WorldWideScience

Sample records for actuator based reconfigurable

  1. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure.

    Directory of Open Access Journals (Sweden)

    Bo Zhao

    Full Text Available This paper considers a decentralized fault tolerant control (DFTC scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO. Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations.

  2. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure

    Science.gov (United States)

    Zhao, Bo; Li, Yuanchun

    2015-01-01

    This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations. PMID:26181826

  3. Casting traceability with direct part marking using reconfigurable pin-type tooling based on paraffin–graphite actuators

    DEFF Research Database (Denmark)

    Vedel-Smith, Nikolaj Kjelgaard; Lenau, Torben Anker

    2012-01-01

    Green sand moulding machines for cast iron foundries are presently unable to uniquely identify individual castings. An insert tool concept is developed and tested via incremental mock-up development. The tool is part of the pattern plate and changes shape between each moulding, thus giving each...... mould a unique ID by embossing a Data Matrix symbol into the sand. In the process of producing the mould, each casting can be given a unique (DPM), enabling part tracking throughout the casting's life cycle. Sand embossing is achieved with paraffin-actuated reconfigurable pin-type tooling under...... simulated processing conditions. The marker geometry limitations have been tested using static symbol patterns, both for sand embossing and actual casting marking. The marked castings have successfully been identified with decoding software. The study shows that the function of each element...

  4. Analysis of Reconfigured Control Loop with a Virtual Actuator

    Directory of Open Access Journals (Sweden)

    Anna Filasova

    2011-01-01

    Full Text Available Control reconfiguration changes the control structure in response to a fault detected in the plant. This becomes necessary, because a major fault like loss of an actuator breaks the corresponding control loop and therefore renders the whole system inoperable.  An important aim of control reconfiguration is to change the control structure as little as possible, since every change bears the potential of practical problems. The proposed solution is to keep the original controller in the loop and to add an extension called virtual actuator that implements the necessary changes of the control structure. The virtual actuator translates between the signals of the nominal controller and the signal of the faulty plants. This paper is concerned with the analysis of reconfigured loop with a virtual actuator for the system with the faulty actuator. The proposed analysis is illustrated on numerical example.

  5. Reconfigurable Control of Input Affine Nonlinear Systems under Actuator Fault

    DEFF Research Database (Denmark)

    Tabatabaeipour, Mojtaba; Galeazzi, Roberto

    2015-01-01

    loop is preserved. The RB is realized by a virtual actuator and a reference model. Using notions of incremental and input-to-state stability (ISS), it is shown that ISS of the closed-loop reconfigured system can be achieved by the separate design of the virtual actuator. The proposed method does...... not need any knowledge of the nominal controller and only assumes that the nominal closed-loop system is ISS. The method is demonstrated on a dynamic positioning system for an offshore supply vessel, where the virtual actuator is designed using backstepping....

  6. Distributed sensor and actuator reconfiguration for fault-tolerant networked control systems

    NARCIS (Netherlands)

    Herdeiro Teixeira, A.M.; Araujo, Jose; Sandberg, Henrik; Johansson, Karl H.

    2017-01-01

    In this paper, we address the problem of distributed reconfiguration of networked control systems upon the removal of misbehaving sensors and actuators. In particular, we consider systems with redundant sensors and actuators cooperating to recover from faults. Reconfiguration is performed while

  7. Towards automatic model based controller design for reconfigurable plants

    DEFF Research Database (Denmark)

    Michelsen, Axel Gottlieb; Stoustrup, Jakob; Izadi-Zamanabadi, Roozbeh

    2008-01-01

    This paper introduces model-based Plug and Play Process Control, a novel concept for process control, which allows a model-based control system to be reconfigured when a sensor or an actuator is plugged into a controlled process. The work reported in this paper focuses on composing a monolithic m...

  8. 10–25 GHz frequency reconfigurable MEMS 5-bit phase shifter using push–pull actuator based toggle mechanism

    International Nuclear Information System (INIS)

    Dey, Sukomal; Koul, Shiban K

    2015-01-01

    This paper presents a frequency tunable 5-bit true-time-delay digital phase shifter using radio frequency microelectromechanical system (RF MEMS) technology. The phase shifter is based on the distributed MEMS transmission line (DMTL) concept utilizing a MEMS varactor. The main source of frequency tuning in this work is a bridge actuation mechanism followed by capacitance variation. Two stages of actuation mechanisms (push and pull) are used to achieve a 2:1 tuning ratio. Accurate control of the actuation voltage between the pull to push stages contributes differential phase shift over the band of interest. The functional behavior of the push–pull actuation over the phase shifter application is theoretically established, experimentally investigated and validated with simulation. The phase shifter is fabricated monolithically using a gold based surface micromachining process on an alumina substrate. The individual primary phase-bits (11.25°/22.5°/45°/90°/180°) that are the fundamental building blocks of the complete 5-bit phase shifter are designed, fabricated and experimentally characterized from 10–25 GHz for specific applications. Finally, the complete 5-bit phase shifter demonstrates an average phase error of 4.32°, 2.8°, 1° and 1.58°, an average insertion loss of 3.76, 4.1, 4.2 and 4.84 dB and an average return loss of 11.7, 12, 14 and 11.8 dB at 10, 12, 17.2 and 25 GHz, respectively. To the best of the authors’ knowledge, this is the first reported band tunable stand alone 5-bit phase shifter in the literature which can work over the large spectrum for different applications. The total area of the 5-bit phase shifter is 15.6 mm 2 . Furthermore, the cold-switched reliability of the unit cell and the complete 5-bit MEMS phase shifter are extensively investigated and presented. (paper)

  9. Reconfigurability of Piecewise Affine Systems Against Actuator Faults

    DEFF Research Database (Denmark)

    Tabatabaeipour, Seyed Mojtaba; Gholami, Mehdi; Bak, Thomas

    2011-01-01

    In this paper, we consider the problem of recongurability of peicewise ane (PWA) systems. Actuator faults are considered. A system subject to a fault is considered as recongurable if it can be stabilized by a state feedback controller and the optimal cost of the performance of the systems...

  10. Characterization of a piezoelectric MEMS actuator surface toward motion-enabled reconfigurable RF circuits

    Science.gov (United States)

    Tellers, M. C.; Pulskamp, J. S.; Bedair, S. S.; Rudy, R. Q.; Kierzewski, I. M.; Polcawich, R. G.; Bergbreiter, S. E.

    2018-03-01

    As an alternative to highly constrained hard-wired reconfigurable RF circuits, a motion-enabled reconfigurable circuit (MERC) offers freedom from transmission line losses and homogeneous materials selection. The creation of a successful MERC requires a precise mechanical mechanism for relocating components. In this work, a piezoelectric MEMS actuator array is modeled and experimentally characterized to assess its viability as a solution to the MERC concept. Actuation and design parameters are evaluated, and the repeatability of high quality on-axis motion at greater than 1 mm s-1 is demonstrated with little positional error. Finally, an initial proof-of-concept circuit reconfiguration has been demonstrated using off-the-shelf RF filter components. Although initial feasibility tests show filter performance degradation with an additional insertion loss of 0.3 dB per contact, out-of-band rejection degradation as high as 10 dB, and ripple performance reduction from 0.25 dB to 1.5 dB, MERC is proven here as an alternative to traditional approaches used in reconfigurable RF circuit applications.

  11. Intelligent design optimization of a shape-memory-alloy-actuated reconfigurable wing

    Science.gov (United States)

    Lagoudas, Dimitris C.; Strelec, Justin K.; Yen, John; Khan, Mohammad A.

    2000-06-01

    The unique thermal and mechanical properties offered by shape memory alloys (SMAs) present exciting possibilities in the field of aerospace engineering. When properly trained, SMA wires act as linear actuators by contracting when heated and returning to their original shape when cooled. It has been shown experimentally that the overall shape of an airfoil can be altered by activating several attached SMA wire actuators. This shape-change can effectively increase the efficiency of a wing in flight at several different flow regimes. To determine the necessary placement of these wire actuators within the wing, an optimization method that incorporates a fully-coupled structural, thermal, and aerodynamic analysis has been utilized. Due to the complexity of the fully-coupled analysis, intelligent optimization methods such as genetic algorithms have been used to efficiently converge to an optimal solution. The genetic algorithm used in this case is a hybrid version with global search and optimization capabilities augmented by the simplex method as a local search technique. For the reconfigurable wing, each chromosome represents a realizable airfoil configuration and its genes are the SMA actuators, described by their location and maximum transformation strain. The genetic algorithm has been used to optimize this design problem to maximize the lift-to-drag ratio for a reconfigured airfoil shape.

  12. An Ionic-Polymer-Metallic Composite Actuator for Reconfigurable Antennas in Mobile Devices

    Directory of Open Access Journals (Sweden)

    Yi-Chen Lin

    2014-01-01

    Full Text Available In this paper, a new application of an electro-active-polymer for a radio frequency (RF switch is presented. We used an ionic polymer metallic composite (IPMC switch to change the operating frequency of an inverted-F antenna. This switch is light in weight, small in volume, and low in cost. In addition, the IPMC is suitable for mobile devices because of its driving voltage of 3 volts and thickness of 200 μm. The IPMC acts as a normally-on switch to control the operating frequency of a reconfigurable antenna in mobile phones. We experimentally demonstrated by network analysis that the IPMC switch could shift its operating frequency from 1.1 to 2.1 GHz, with return losses of than −10 dB at both frequencies. To minimize electrolysis and maximize the operation time in air, propylene carbonate electrolyte with lithium perchlorate (LiClO4 was applied inside the IPMC. The results showed that when the IPMC was actuated over three months at 3.5 V, the tip displacement fell by less than 10%. Therefore, an IPMC actuator is a promising choice for application to a reconfigurable antenna.

  13. Dynamic Output Feedback Based Active Decentralized Fault-Tolerant Control for Reconfigurable Manipulator with Concurrent Failures

    Directory of Open Access Journals (Sweden)

    Yuanchun Li

    2015-01-01

    Full Text Available The goal of this paper is to describe an active decentralized fault-tolerant control (ADFTC strategy based on dynamic output feedback for reconfigurable manipulators with concurrent actuator and sensor failures. Consider each joint module of the reconfigurable manipulator as a subsystem, and treat the fault as the unknown input of the subsystem. Firstly, by virtue of linear matrix inequality (LMI technique, the decentralized proportional-integral observer (DPIO is designed to estimate and compensate the sensor fault online; hereafter, the compensated system model could be derived. Then, the actuator fault is estimated similarly by another DPIO using LMI as well, and the sufficient condition of the existence of H∞ fault-tolerant controller in the dynamic output feedback is presented for the compensated system model. Furthermore, the dynamic output feedback controller is presented based on the estimation of actuator fault to realize active fault-tolerant control. Finally, two 3-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in simulation. The main advantages of the proposed scheme lie in that it can handle the concurrent faults act on the actuator and sensor on the same joint module, as well as there is no requirement of fault detection and isolation process; moreover, it is more feasible to the modularity of the reconfigurable manipulator.

  14. An FPGA-based reconfigurable DDC algorithm

    Science.gov (United States)

    Juszczyk, B.; Kasprowicz, G.

    2016-09-01

    This paper describes implementation of reconfigurable digital down converter in an FPGA structure. System is designed to work with quadrature signals. One of the main criteria of the project was to provied wide range of reconfiguration in order to fulfill various application rage. Potential applications include: software defined radio receiver, passive noise radars and measurement data compression. This document contains general system overview, short description of hardware used in the project and gateware implementation.

  15. Autonomous Reconfiguration Procedures for EJB-based Enterprise Applications

    OpenAIRE

    Vogel, Thomas; Bruhn, Jens; Wirtz, Guido

    2018-01-01

    Enterprise Applications (EA) are complex software systems for supporting the business of companies. Evolution of an EA should not affect its availability, e.g., because of a temporal shutdown, business operations may be affected. One possibility to address this problem is the seamless reconfiguration of the affected EA, i.e., applying the relevant changes while the system is running. Our approach to seamless reconfiguration focuses on component-oriented EAs. It is based on the Autonomic Compu...

  16. Control Reconfiguration of LPV Systems Using Virtual Sensor and Virtual Actuator

    DEFF Research Database (Denmark)

    Tabatabaeipour, Seyed Mojtaba; Stoustrup, Jakob; Bak, Thomas

    2012-01-01

    the plant and the nominal controller such that the fault tolerant goal is achieved without re-designing the nominal controller. The role of the reconfiguration block is to transform the signals from the faulty system such that its behavior is similar to the nominal system from the point of view...

  17. A Reconfiguration Scheme for Accommodating Actuator Failures in Multi-Input, Multi-Output Flight Control Systems

    Science.gov (United States)

    Siwakosit, W.; Hess, R. A.; Bacon, Bart (Technical Monitor); Burken, John (Technical Monitor)

    2000-01-01

    A multi-input, multi-output reconfigurable flight control system design utilizing a robust controller and an adaptive filter is presented. The robust control design consists of a reduced-order, linear dynamic inversion controller with an outer-loop compensation matrix derived from Quantitative Feedback Theory (QFT). A principle feature of the scheme is placement of the adaptive filter in series with the QFT compensator thus exploiting the inherent robustness of the nominal flight control system in the presence of plant uncertainties. An example of the scheme is presented in a pilot-in-the-loop computer simulation using a simplified model of the lateral-directional dynamics of the NASA F18 High Angle of Attack Research Vehicle (HARV) that included nonlinear anti-wind up logic and actuator limitations. Prediction of handling qualities and pilot-induced oscillation tendencies in the presence of these nonlinearities is included in the example.

  18. Sensor and Actuator Fault-Hiding Reconfigurable Control Design for a Four-Tank System Benchmark

    DEFF Research Database (Denmark)

    Hameed, Ibrahim; El-Madbouly, Esam I; Abdo, Mohamed I

    2015-01-01

    Invariant (LTI) system where virtual sensors and virtual actuators are used to correct faulty performance through the use of a pre-fault performance. Simulation results showed that the developed approach can handle different types of faults and able to completely and instantly recover the original system......Fault detection and compensation plays a key role to fulfill high demands for performance and security in today's technological systems. In this paper, a fault-hiding (i.e., tolerant) control scheme that detects and compensates for actuator and sensor faults in a four-tank system benchmark...

  19. Aircraft Attitude Distributed Fault-tolerant Control Based on Dynamic Actuator

    Directory of Open Access Journals (Sweden)

    Zhou Hong-Cheng

    2014-09-01

    Full Text Available For attitude control system, based on decentralized fault-tolerant control framework, actuators damage and stuck fault detection and identification unit are designed for the flight control system. And observer-based auxiliary system unit is also designed. The auxiliary system implies control surface damage faults and disturbances information. Firstly, we give the attitude control system under actuator stuck, lose of effectiveness, and control surface damages faults. Secondly, a multi-observer is designed for actuator fault detection and identification using a decision-making mechanism to determine current actuator failure modes. Then, an adaptive sliding mode observer is designed for implicit control surface damages and interference information. The reconfigurable controller can achieve fault tolerant using the information of adaptive sliding mode observer. Finally, the simulation results show the effectiveness of the proposed method.

  20. Homogeneous and single-side-operational connector mechanism for self-reconfigurable, self-assembly and self-healing systems

    Science.gov (United States)

    Shen, Wei-Min (Inventor); Kovac, Robert M. (Inventor)

    2012-01-01

    Designs of single-end-operative reconfigurable genderless connectors that include a base, a plurality of movable jaws that are formed on the base and can engage to the jaws of another connector, and an actuator that is mounted on the base and can engage and move the jaws of the reconfigurable connector to connect the reconfigurable connector with another connector.

  1. Reconfigurable dual-band metamaterial antenna based on liquid crystals

    Science.gov (United States)

    Che, Bang-Jun; Meng, Fan-Yi; Lyu, Yue-Long; Wu, Qun

    2018-05-01

    In this paper, a novel reconfigurable dual-band metamaterial antenna with a continuous beam that is electrically steered in backward to forward directions is first proposed by employing a liquid crystal (LC)-loaded tunable extended composite right-/left-handed (E-CRLH) transmission line (TL). The frequency-dependent property of the E-CRLH TL is analyzed and a compact unit cell based on the nematic LC is proposed to realize the tunable dual band characteristics. The phase constant of the proposed unit cell can be dynamically continuously tuned from negative to positive values in two operating bands by changing the bias voltage of the loaded LC material. A resulting dual band fixed-frequency beam steering property has been predicted by numerical simulations and experimentally verified. The measured results show that the fabricated reconfigurable antenna features an electrically controlled continuous beam steering from backward  ‑16° to forward  +13° at 7.2 GHz and backward  ‑9° to forward  +17° at 9.4 GHz, respectively. This electrically controlled beam steering range turns out to be competitive with the previously reported single band reconfigurable antennas. Besides, the measured and simulated results of the proposed reconfigurable dual-band metamaterial antenna are in good agreement.

  2. Reconfigurable chaotic logic gates based on novel chaotic circuit

    International Nuclear Information System (INIS)

    Behnia, S.; Pazhotan, Z.; Ezzati, N.; Akhshani, A.

    2014-01-01

    Highlights: • A novel method for implementing logic gates based on chaotic maps is introduced. • The logic gates can be implemented without any changes in the threshold voltage. • The chaos-based logic gates may serve as basic components of future computing devices. - Abstract: The logical operations are one of the key issues in today’s computer architecture. Nowadays, there is a great interest in developing alternative ways to get the logic operations by chaos computing. In this paper, a novel implementation method of reconfigurable logic gates based on one-parameter families of chaotic maps is introduced. The special behavior of these chaotic maps can be utilized to provide same threshold voltage for all logic gates. However, there is a wide interval for choosing a control parameter for all reconfigurable logic gates. Furthermore, an experimental implementation of this nonlinear system is presented to demonstrate the robustness of computing capability of chaotic circuits

  3. Solida: A Blockchain Protocol Based on Reconfigurable Byzantine Consensus

    OpenAIRE

    Abraham, Ittai; Malkhi, Dahlia; Nayak, Kartik; Ren, Ling; Spiegelman, Alexander

    2018-01-01

    The decentralized cryptocurrency Bitcoin has experienced great success but also encountered many challenges. One of the challenges has been the long confirmation time. Another chal- lenge is the lack of incentives at certain steps of the protocol, raising concerns for transaction withholding, selfish mining, etc. To address these challenges, we propose Solida, a decentralized blockchain protocol based on reconfigurable Byzantine consensus augmented by proof-of-work. Solida improves on Bitcoin...

  4. Solida: A Blockchain Protocol Based on Reconfigurable Byzantine Consensus

    OpenAIRE

    Abraham, Ittai; Malkhi, Dahlia; Nayak, Kartik; Ren, Ling; Spiegelman, Alexander

    2016-01-01

    The decentralized cryptocurrency Bitcoin has experienced great success but also encountered many challenges. One of the challenges has been the long confirmation time. Another challenge is the lack of incentives at certain steps of the protocol, raising concerns for transaction withholding, selfish mining, etc. To address these challenges, we propose Solida, a decentralized blockchain protocol based on reconfigurable Byzantine consensus augmented by proof-of-work. Solida improves on Bitcoin i...

  5. Design and Fabrication of a Reconfigurable MEMS-Based Antenna

    KAUST Repository

    Martinez, Miguel Angel Galicia

    2011-06-22

    This thesis presents the design and fabrication of a customized in house Micro-Electro-Mechanical-Systems (MEMS) process based on-chip antenna that is both frequency and polarization reconfigurable. It is designed to work at both 60 GHz and 77 GHz through MEMS switches. This antenna can also work in both horizontal and vertical linear polarizations by utilizing a moveable plate. The design is intended for Wireless Personal Area Networks (WPAN) and automotive radar applications. Typical on-chip antennas are inefficient and difficult to reconfigure. Therefore, the focus of this work is to develop an efficient on-chip antenna solution, which is reconfigurable in frequency and in polarization. A fractal bowtie antenna is employed for this thesis, which achieves frequency reconfigurability through MEMS switches. The design is simulated in industry standard Electromagnetic (EM) simulator Ansoft HFSS. A novel concept for horizontal to vertical linear polarization agility is introduced which incorporates a moveable polymer plate. For this work, a microprobe is used to move the plate from the horizontal to vertical position. For testing purposes, a novel mechanism has been designed in order to feed the antenna with RF-probes in both horizontal and vertical positions. A simulated gain of approximately 0 dB is achieved at both target frequencies (60 and 77 GHz), in both horizontal and vertical positions. In all the cases mentioned above (both frequencies and positions), the antenna is well matched (< -10 dB) to the 50 Ω system impedance. Similarly, the radiation nulls are successfully shifted by changing the position of the antenna from horizontal to vertical. The complete design and fabrication of the reconfigurable MEMS antenna has been done at KAUST facilities. Some challenges have been encountered during its realization due to the immaturity of the customized MEMS fabrication process. Nonetheless, a first fabrication attempt has highlighted such shortcomings. According

  6. Experimental/analytical determination of optimal piezoelectric actuator locations on complex structures based on the actuator power factor

    OpenAIRE

    Bhargava, Adesh

    1995-01-01

    The actuator power factor is defined as the ratio of the total dissipative mechanical power of a PZT actuator to the total supplied electrical power to the PZT actuator. If measured experimentally, it can be used to optinlize the actuator location and configuration for complex structures. The concept of actuator power factor is based on the ability of an integrated induced strain actuator such as a PZT actuator to transfer supplied electrical energy into structural mechanical energy. For a gi...

  7. Liquid metal-based reconfigurable and stretchable photolithography

    International Nuclear Information System (INIS)

    Kim, Daeyoung; Yoo, Jun Hyeon; Lee, Jeong-Bong

    2016-01-01

    Conventional ultraviolet (UV) lithography typically uses a photomask made of a fused silica plate covered with a layer of UV opaque material such as chromium. The photomask has passive binary patterns of UV opaque and UV transparent regions and the pattern is unalterable. We report a novel real-time dynamically reconfigurable photomask technology using a liquid metal (as a UV opaque material) filled in polydimethylsiloxane (PDMS, as a UV transparent material) microfluidic channels. We found that the gallium-based liquid metal (e.g. Galinstan ® ) is opaque in broad spectrum of light in the wavelength from 325 nm to 850 nm while the PDMS is highly transparent in this wide range of spectrum. We made both bright field and dark field microfluidic photomasks and transferred various patterns onto a positive photoresist. A 7-segment display microfluidic channel photomask was also fabricated and decimal numerals (from ‘0’ to ‘9’) were patterned with one photomask by dynamically reconfiguring decimal numeral shapes with on-demand injection and withdrawal of the liquid metal in specific segment microfluidic channels in the photomask. In addition, utilizing mechanical flexibility of the PDMS and the liquid metal, reconfiguration of the patterns in a microfluidic photomask under stretching was successfully tested. (paper)

  8. Graphene-nanoplatelet-based photomechanical actuators

    International Nuclear Information System (INIS)

    Loomis, James; King, Ben; Burkhead, Tom; Xu Peng; Bessler, Nathan; Panchapakesan, Balaji; Terentjev, Eugene

    2012-01-01

    This paper reports large light-induced reversible and elastic responses of graphene nanoplatelet (GNP) polymer composites. Homogeneous mixtures of GNP/polydimethylsiloxane (PDMS) composites (0.1–5 wt%) were prepared and their infrared (IR) mechanical responses studied with increasing pre-strains. Using IR illumination, a photomechanically induced change in stress of four orders of magnitude as compared to pristine PDMS polymer was measured. The actuation responses of the graphene polymer composites depended on the applied pre-strains. At low levels of pre-strain (3–9%) the actuators showed reversible expansion while at high levels (15–40%) the actuators exhibited reversible contraction. The GNP/PDMS composites exhibited higher actuation stresses compared to other forms of nanostructured carbon/PDMS composites, including carbon nanotubes (CNTs), for the same fabrication method. An extraordinary optical-to-mechanical energy conversion factor (η M ) of 7–9 MPa W −1 for GNP-based polymer composite actuators is reported. (paper)

  9. Optically reconfigurable metasurfaces and photonic devices based on phase change materials

    Science.gov (United States)

    Wang, Qian; Rogers, Edward T. F.; Gholipour, Behrad; Wang, Chih-Ming; Yuan, Guanghui; Teng, Jinghua; Zheludev, Nikolay I.

    2016-01-01

    Photonic components with adjustable parameters, such as variable-focal-length lenses or spectral filters, which can change functionality upon optical stimulation, could offer numerous useful applications. Tuning of such components is conventionally achieved by either micro- or nanomechanical actuation of their constituent parts, by stretching or by heating. Here, we report a novel approach for making reconfigurable optical components that are created with light in a non-volatile and reversible fashion. Such components are written, erased and rewritten as two-dimensional binary or greyscale patterns into a nanoscale film of phase-change material by inducing a refractive-index-changing phase transition with tailored trains of femtosecond pulses. We combine germanium-antimony-tellurium-based films with a diffraction-limited resolution optical writing process to demonstrate a variety of devices: visible-range reconfigurable bichromatic and multi-focus Fresnel zone plates, a super-oscillatory lens with subwavelength focus, a greyscale hologram, and a dielectric metamaterial with on-demand reflection and transmission resonances.

  10. Acquisition-based Dynamic Reconfiguration Capabilities

    NARCIS (Netherlands)

    Amiryany Araghy, N.; Huysman, M.H.; de Man, A.P.; Cloodt, M.; Demetriss, V.; Weber, Y.; Kaufmann, R.; Tarba, S.

    2009-01-01

    The success of knowledge acquisitions is dependent upon firm’s ability to integrate knowledge-based resources and thus share knowledge, in order to innovate. Regardless of the increasing number of knowledge acquisitions, however, an understanding of how successful firms direct their knowledge

  11. Soft Sensors and Actuators based on Nanomaterials

    Science.gov (United States)

    Yao, Shanshan

    The focus of this research is using novel bottom-up synthesized nanomaterials and structures to build up devices for wearable sensors and soft actuators. The applications of the wearable sensors towards motion detection and health monitoring are investigated. In addition, flexible heaters for bimorph actuators and stretchable patches made of microgel depots containing drug-loaded nanoparticles (NPs) for stretch-triggered wearable drug delivery are studied. Considerable efforts have been made to achieve highly sensitive and wearable sensors that can simultaneously detect multiple stimuli such as stretch, pressure, temperature or touch. Highly stretchable multifunctional sensors that can detect strain (up to 50%), pressure (up to 1 MPa) and finger touch with good sensitivity, fast response time ( 40 ms) and good pressure mapping function were developed. The sensors were demonstrated for several wearable applications including monitoring thumb movements and knee motions, illustrating the potential utilities of such sensors in robotic systems, prosthetics, healthcare and flexible touch panels. In addition to mechanical sensors, a wearable skin hydration sensor made of silver nanowires (AgNWs) in a polydimethylsiloxane (PDMS) matrix was demonstrated based on skin impedance measurement. The hydration sensors were packaged into a flexible wristband for skin hydration monitoring and a chest patch consisting of a strain sensor, three electrocardiogram (ECG) electrodes and a skin hydration sensor for multimodal sensing. The wearable wristband and chest patch may be used for low-cost, wireless and continuous sensing of skin hydration and other health parameters. Two representative applications of the nanomaterials for soft actuators were investigated. In the first application on bimorph actuation, low-voltage and extremely flexible electrothermal bimorph actuators were fabricated in a simple, efficient and scalable process. The bimorph actuators were made of flexible Ag

  12. Solid electroytes for CNT-based actuators

    Science.gov (United States)

    Riemenschneider, Johannes; Geier, Sebastian; Mahrholz, Thorsten; Mosch, Jürgen; Monner, Hans Peter; Sinapius, Michael

    2009-03-01

    Actuators based on carbon nanotubes (CNT) have the potential to generate high forces at very low voltages. The density of the raw material is just 1330 kg/m3, which makes them well applicable for lightweight applications. Moreover, active strains of up to 1% can be achieved - due to the CNTs dimensional changes on charge injection. Therefore the nanotubes have to be arranged and electrically wired like electrodes of a capacitor. In previous works the system's response of the Nanotubes comprising a liquid electrolyte was studied in detail. The major challenge is to repeat such experiments with solid electrolytes, which is a prerequisite for structural integration. In this paper a method is proposed which makes sure the expansion is not based on thermal expansion. This is done by analysing the electrical system response. As thermal expansion is dominated by ohmic resistance the CNT based actuators show a strong capacitive behavior. This behavior is referable to the constitution of the electrochemical double layer around the nanotubes, which causes the tubes to expand. Also a novel test setup is described, which guarantees that the displacement which is measured will not be caused by bending of a bimorph but due to expansion of a single layer of nanotubes. This paper also presents experimental results demonstrating both, the method of electrical characterization of CNT based actuators with implemented solid electrolytes and the novel test setup which is used to measure the needed data. The actuators which were characterized are hybrids of CNT and the solid electrolyte NAFION which is supplying the ions needed to constitute the electrochemical double layer. The manufacturing, processing of these actuators and also some first experimental results are shown. Unfortunately, the results are not as clear as those for liquid electrolytes, which depend on the hybrid character of the analyzed devices. In the liquid electrolyte based case the CNTs are the only source of

  13. Integrated reconfigurable photonic filters based on interferometric fractional Hilbert transforms.

    Science.gov (United States)

    Sima, C; Cai, B; Liu, B; Gao, Y; Yu, Y; Gates, J C; Zervas, M N; Smith, P G R; Liu, D

    2017-10-01

    In this paper, we present integrated reconfigurable photonic filters using fractional Hilbert transformers (FrHTs) and optical phase tuning structure within the silica-on-silicon platform. The proposed structure, including grating-based FrHTs, an X-coupler, and a pair of thermal tuning filaments, is fabricated through the direct UV grating writing technique. The thermal tuning effect is realized by the controllable microheaters located on the two arms of the X-coupler. We investigate the 200 GHz maximum bandwidth photonic FrHTs based on apodized planar Bragg gratings, and analyze the reflection spectrum responses. Through device integration and thermal modulation, the device could operate as photonic notch filters with 5 GHz linewidth and controllable single sideband suppression filters with measured 12 dB suppression ratio. A 50 GHz instantaneous frequency measuring system using this device is also schematically proposed and analyzed with potential 3 dB measurement improvement. The device could be configured with these multiple functions according to need. The reconfigurable structure has great potential in ultrafast all-optical signal processing fields.

  14. Gallium-Based Room-Temperature Liquid Metals: Actuation and Manipulation of Droplets and Flows

    Directory of Open Access Journals (Sweden)

    Leily Majidi

    2017-08-01

    Full Text Available Gallium-based room-temperature liquid metals possess extremely valuable properties, such as low toxicity, low vapor pressure, and high thermal and electrical conductivity enabling them to become suitable substitutes for mercury and beyond in wide range of applications. When exposed to air, a native oxide layer forms on the surface of gallium-based liquid metals which mechanically stabilizes the liquid. By removing or reconstructing the oxide skin, shape and state of liquid metal droplets and flows can be manipulated/actuated desirably. This can occur manually or in the presence/absence of a magnetic/electric field. These methods lead to numerous useful applications such as soft electronics, reconfigurable devices, and soft robots. In this mini-review, we summarize the most recent progresses achieved on liquid metal droplet generation and actuation of gallium-based liquid metals with/without an external force.

  15. Nanostructured carbon materials based electrothermal air pump actuators

    Science.gov (United States)

    Liu, Qing; Liu, Luqi; Kuang, Jun; Dai, Zhaohe; Han, Jinhua; Zhang, Zhong

    2014-05-01

    Actuator materials can directly convert different types of energy into mechanical energy. In this work, we designed and fabricated electrothermal air pump-type actuators by utilization of various nanostructured carbon materials, including single wall carbon nanotubes (SWCNTs), reduced graphene oxide (r-GO), and graphene oxide (GO)/SWCNT hybrid films as heating elements to transfer electrical stimulus into thermal energy, and finally convert it into mechanical energy. Both the actuation displacement and working temperature of the actuator films show the monotonically increasing trend with increasing driving voltage within the actuation process. Compared with common polymer nanocomposites based electrothermal actuators, our actuators exhibited better actuation performances with a low driving voltage (film actuator due to the intrinsic gas-impermeability nature of graphene platelets. In addition, the high modulus of the r-GO and GO/SWCNT films also guaranteed the large generated stress and high work density. Specifically, the generated stress and gravimetric work density of the GO/SWCNT hybrid film actuator could reach up to more than 50 MPa and 30 J kg-1, respectively, under a driving voltage of 10 V. The resulting stress value is at least two orders of magnitude higher than that of natural muscles (~0.4 MPa).Actuator materials can directly convert different types of energy into mechanical energy. In this work, we designed and fabricated electrothermal air pump-type actuators by utilization of various nanostructured carbon materials, including single wall carbon nanotubes (SWCNTs), reduced graphene oxide (r-GO), and graphene oxide (GO)/SWCNT hybrid films as heating elements to transfer electrical stimulus into thermal energy, and finally convert it into mechanical energy. Both the actuation displacement and working temperature of the actuator films show the monotonically increasing trend with increasing driving voltage within the actuation process. Compared with

  16. Optimal reconfiguration-based dynamic tariff for congestion management and line loss reduction in distribution networks

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei; Cheng, Lin

    2016-01-01

    This paper presents an optimal reconfiguration-based dynamic tariff (DT) method for congestion management and line loss reduction in distribution networks with high penetration of electric vehicles. In the proposed DT concept, feeder reconfiguration (FR) is employed through mixed integer programm...

  17. Study on data acquisition system based on reconfigurable cache technology

    Science.gov (United States)

    Zhang, Qinchuan; Li, Min; Jiang, Jun

    2018-03-01

    Waveform capture rate is one of the key features of digital acquisition systems, which represents the waveform processing capability of the system in a unit time. The higher the waveform capture rate is, the larger the chance to capture elusive events is and the more reliable the test result is. First, this paper analyzes the impact of several factors on the waveform capture rate of the system, then the novel technology based on reconfigurable cache is further proposed to optimize system architecture, and the simulation results show that the signal-to-noise ratio of signal, capacity, and structure of cache have significant effects on the waveform capture rate. Finally, the technology is demonstrated by the engineering practice, and the results show that the waveform capture rate of the system is improved substantially without significant increase of system's cost, and the technology proposed has a broad application prospect.

  18. A Reconfigurable Logic Cell Based on a Simple Dynamical System

    Directory of Open Access Journals (Sweden)

    Lixiang Li

    2013-01-01

    Full Text Available This paper introduces a new scheme to achieve a dynamic logic gate which can be adjusted flexibly to obtain different logic functions by adjusting specific parameters of a dynamical system. Based on graphical tools and the threshold mechanism, the distribution of different logic gates is studied, and a transformation method between different logics is given. Analyzing the performance of the dynamical system in the presence of noise, we discover that it is resistant to system noise. Moreover, we find some part of the system can be considered as a leaky integrator which has been already widely applied in engineering. Finally, we provide a proof-of-principle hardware implementation of the proposed scheme to illustrate its effectiveness. With the proposed scheme in hand, it is convenient to build the flexible, robust, and general purpose computing devices such as various network coding routers, communication encoders or decoders, and reconfigurable computer chips.

  19. Trajectory Generation and Stability Analysis for Reconfigurable Klann Mechanism Based Walking Robot

    Directory of Open Access Journals (Sweden)

    Jaichandar Kulandaidaasan Sheba

    2016-06-01

    Full Text Available Reconfigurable legged robots based on one degree of freedom are highly desired because they are effective on rough and irregular terrains and they provide mobility in such terrain with simple control schemes. It is necessary that reconfigurable legged robots should maintain stability during rest and motion, with a minimum number of legs while maintaining their full range of walking patterns resulting from different gait configuration. In this paper we present a method to generate input trajectory for reconfigurable quadruped robots based on Klann mechanism to properly synchronize movement. Six useful gait cycles based on this reconfigurable Klann mechanism for quadruped robots has been clearly shown here. The platform stability for these six useful gait cycles are validated through simulated results which clearly shows the capabilities of reconfigurable design.

  20. Another Lesson from Plants: The Forward Osmosis-Based Actuator

    Science.gov (United States)

    Sinibaldi, Edoardo; Argiolas, Alfredo; Puleo, Gian Luigi; Mazzolai, Barbara

    2014-01-01

    Osmotic actuation is a ubiquitous plant-inspired actuation strategy that has a very low power consumption but is capable of generating effective movements in a wide variety of environmental conditions. In light of these features, we aimed to develop a novel, low-power-consumption actuator that is capable of generating suitable forces during a characteristic actuation time on the order of a few minutes. Based on the analysis of plant movements and on osmotic actuation modeling, we designed and fabricated a forward osmosis-based actuator with a typical size of 10 mm and a characteristic time of 2–5 minutes. To the best of our knowledge, this is the fastest osmotic actuator developed so far. Moreover, the achieved timescale can be compared to that of a typical plant cell, thanks to the integrated strategy that we pursued by concurrently addressing and solving design and material issues, as paradigmatically explained by the bioinspired approach. Our osmotic actuator produces forces above 20 N, while containing the power consumption (on the order of 1 mW). Furthermore, based on the agreement between model predictions and experimental observations, we also discuss the actuator performance (including power consumption, maximum force, energy density and thermodynamic efficiency) in relation to existing actuation technologies. In light of the achievements of the present study, the proposed osmotic actuator holds potential for effective exploitation in bioinspired robotics systems. PMID:25020043

  1. Another lesson from plants: the forward osmosis-based actuator.

    Science.gov (United States)

    Sinibaldi, Edoardo; Argiolas, Alfredo; Puleo, Gian Luigi; Mazzolai, Barbara

    2014-01-01

    Osmotic actuation is a ubiquitous plant-inspired actuation strategy that has a very low power consumption but is capable of generating effective movements in a wide variety of environmental conditions. In light of these features, we aimed to develop a novel, low-power-consumption actuator that is capable of generating suitable forces during a characteristic actuation time on the order of a few minutes. Based on the analysis of plant movements and on osmotic actuation modeling, we designed and fabricated a forward osmosis-based actuator with a typical size of 10 mm and a characteristic time of 2-5 minutes. To the best of our knowledge, this is the fastest osmotic actuator developed so far. Moreover, the achieved timescale can be compared to that of a typical plant cell, thanks to the integrated strategy that we pursued by concurrently addressing and solving design and material issues, as paradigmatically explained by the bioinspired approach. Our osmotic actuator produces forces above 20 N, while containing the power consumption (on the order of 1 mW). Furthermore, based on the agreement between model predictions and experimental observations, we also discuss the actuator performance (including power consumption, maximum force, energy density and thermodynamic efficiency) in relation to existing actuation technologies. In light of the achievements of the present study, the proposed osmotic actuator holds potential for effective exploitation in bioinspired robotics systems.

  2. Another lesson from plants: the forward osmosis-based actuator.

    Directory of Open Access Journals (Sweden)

    Edoardo Sinibaldi

    Full Text Available Osmotic actuation is a ubiquitous plant-inspired actuation strategy that has a very low power consumption but is capable of generating effective movements in a wide variety of environmental conditions. In light of these features, we aimed to develop a novel, low-power-consumption actuator that is capable of generating suitable forces during a characteristic actuation time on the order of a few minutes. Based on the analysis of plant movements and on osmotic actuation modeling, we designed and fabricated a forward osmosis-based actuator with a typical size of 10 mm and a characteristic time of 2-5 minutes. To the best of our knowledge, this is the fastest osmotic actuator developed so far. Moreover, the achieved timescale can be compared to that of a typical plant cell, thanks to the integrated strategy that we pursued by concurrently addressing and solving design and material issues, as paradigmatically explained by the bioinspired approach. Our osmotic actuator produces forces above 20 N, while containing the power consumption (on the order of 1 mW. Furthermore, based on the agreement between model predictions and experimental observations, we also discuss the actuator performance (including power consumption, maximum force, energy density and thermodynamic efficiency in relation to existing actuation technologies. In light of the achievements of the present study, the proposed osmotic actuator holds potential for effective exploitation in bioinspired robotics systems.

  3. Piezoelectric-based actuators for improved tractor-trailer performance (Conference Presentation)

    Science.gov (United States)

    Menicovich, David; Amitay, Michael; Gallardo, Daniele

    2017-04-01

    The application of piezo-electrically-driven synthetic-jet-based active flow control to reduce drag on tractor-trailers and to improve thermal mixing in refrigerated trailers was explored on full-scale tests. The active flow control technique that is being used relies on a modular system comprised of distributed, small, highly efficient actuators. These actuators, called synthetic jets, are jets that are synthesized at the edge of an orifice by a periodic motion of a piezoelectric diaphragm(s) mounted on one (or more) walls of a sealed cavity. The synthetic jet is zero net mass flux (ZNMF), but it allows momentum transfer to flow. It is typically driven near diaphragm and/or cavity resonance, and therefore, small electric input [O(10W)] is required. Another advantage of this actuator is that no plumbing is required. The system doesn't require changes to the body of the truck, can be easily reconfigured to various types of vehicles, and consumes small amounts of electrical power from the existing electrical system of the truck. The actuators are operated in a closed feedback loop based on inputs received from the tractor's electronic control unit, various system components and environmental sensors. The data are collected and processed on-board and transmitted to a cloud-based data management platform for further big data analytics and diagnostics. The system functions as a smart connected product through the interchange of data between the physical truck-mounted system and its cloud platform.

  4. A miniaturized reconfigurable broadband attenuator based on RF MEMS switches

    International Nuclear Information System (INIS)

    Guo, Xin; Gong, Zhuhao; Zhong, Qi; Liang, Xiaotong; Liu, Zewen

    2016-01-01

    Reconfigurable attenuators are widely used in microwave measurement instruments. Development of miniaturized attenuation devices with high precision and broadband performance is required for state-of-the-art applications. In this paper, a compact 3-bit microwave attenuator based on radio frequency micro-electro-mechanical system (RF MEMS) switches and polysilicon attenuation modules is presented. The device comprises 12 ohmic contact MEMS switches, π -type polysilicon resistive attenuation modules and microwave compensate structures. Special attention was paid to the design of the resistive network, compensate structures and system simulation. The device was fabricated using micromachining processes compatible with traditional integrated circuit fabrication processes. The reconfigurable attenuator integrated with RF MEMS switches and resistive attenuation modules was successfully fabricated with dimensions of 2.45  ×  4.34  ×  0.5 mm 3 , which is 1/1000th of the size of a conventional step attenuator. The measured RF performance revealed that the attenuator provides 10–70 dB attenuation at 10 dB intervals from 0.1–20 GHz with an accuracy better than  ±1.88 dB at 60 dB and an error of less than 2.22 dB at 10 dB. The return loss of each state of the 3-bit attenuator was better than 11.95 dB (VSWR  <  1.71) over the entire operating band. (paper)

  5. Fabrication and actuation of electro-active polymer actuator based on PSMI-incorporated PVDF

    Science.gov (United States)

    Lu, Jun; Kim, Sang-Gyun; Lee, Sunwoo; Oh, Il-Kwon

    2008-08-01

    In this study, an ionic networking membrane (INM) of poly(styrene-alt-maleimide) (PSMI)-incorporated poly(vinylidene fluoride) (PVDF) was applied to fabricate electro-active polymer. Based on the same original membrane of PSMI-incorporated PVDF, various samples of INM actuator were prepared for different reduction times with the electroless-plating technique. The as-prepared INM actuators were tested in terms of surface resistance, platinum morphology, resonance frequency, tip displacement, current and blocked force, and their performances were compared to those of the widely used traditional Nafion actuator. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that much smaller and more uniform platinum particles were formed on the surfaces of the INM actuators as well as within their polymer matrix. Although excellent harmonic responses were observed for the newly developed INM actuators, they were found to be sensitive to the applied reduction times during the fabrication. The mechanical displacement of the INM actuator fabricated after the optimum reduction times was much larger than that of its Nafion counterpart of comparable thickness under the stimulus of constant and alternating current voltage. The PSMI-incorporated PVDF actuator can become a promising smart material to be used in the fields of biomimetic robots, biomedical devices, sensors and actuator, haptic interfaces, energy harvesting and so on.

  6. Fabrication and actuation of electro-active polymer actuator based on PSMI-incorporated PVDF

    International Nuclear Information System (INIS)

    Lu, Jun; Oh, Il-Kwon; Kim, Sang-Gyun; Lee, Sunwoo

    2008-01-01

    In this study, an ionic networking membrane (INM) of poly(styrene-alt-maleimide) (PSMI)-incorporated poly(vinylidene fluoride) (PVDF) was applied to fabricate electro-active polymer. Based on the same original membrane of PSMI-incorporated PVDF, various samples of INM actuator were prepared for different reduction times with the electroless-plating technique. The as-prepared INM actuators were tested in terms of surface resistance, platinum morphology, resonance frequency, tip displacement, current and blocked force, and their performances were compared to those of the widely used traditional Nafion actuator. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that much smaller and more uniform platinum particles were formed on the surfaces of the INM actuators as well as within their polymer matrix. Although excellent harmonic responses were observed for the newly developed INM actuators, they were found to be sensitive to the applied reduction times during the fabrication. The mechanical displacement of the INM actuator fabricated after the optimum reduction times was much larger than that of its Nafion counterpart of comparable thickness under the stimulus of constant and alternating current voltage. The PSMI-incorporated PVDF actuator can become a promising smart material to be used in the fields of biomimetic robots, biomedical devices, sensors and actuator, haptic interfaces, energy harvesting and so on

  7. Experiencing a Problem-Based Learning Approach for Teaching Reconfigurable Architecture Design

    Directory of Open Access Journals (Sweden)

    Erwan Fabiani

    2009-01-01

    Full Text Available This paper presents the “reconfigurable computing” teaching part of a computer science master course (first year on parallel architectures. The practical work sessions of this course rely on active pedagogy using problem-based learning, focused on designing a reconfigurable architecture for the implementation of an application class of image processing algorithms. We show how the successive steps of this project permit the student to experiment with several fundamental concepts of reconfigurable computing at different levels. Specific experiments include exploitation of architectural parallelism, dataflow and communicating component-based design, and configurability-specificity tradeoffs.

  8. Origami-Based Reconfigurable Metamaterials for Tunable Chirality.

    Science.gov (United States)

    Wang, Zuojia; Jing, Liqiao; Yao, Kan; Yang, Yihao; Zheng, Bin; Soukoulis, Costas M; Chen, Hongsheng; Liu, Yongmin

    2017-07-01

    Origami is the art of folding two-dimensional (2D) materials, such as a flat sheet of paper, into complex and elaborate three-dimensional (3D) objects. This study reports origami-based metamaterials whose electromagnetic responses are dynamically controllable via switching the folding state of Miura-ori split-ring resonators. The deformation of the Miura-ori unit along the third dimension induces net electric and magnetic dipoles of split-ring resonators parallel or anti-parallel to each other, leading to the strong chiral responses. Circular dichroism as high as 0.6 is experimentally observed while the chirality switching is realized by controlling the deformation direction and kinematics. In addition, the relative density of the origami metamaterials can be dramatically reduced to only 2% of that of the unfolded structure. These results open a new avenue toward lightweight, reconfigurable, and deployable metadevices with simultaneously customized electromagnetic and mechanical properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A Reconfigurable Omnidirectional Soft Robot Based on Caterpillar Locomotion.

    Science.gov (United States)

    Zou, Jun; Lin, Yangqiao; Ji, Chen; Yang, Huayong

    2018-04-01

    A pneumatically powered, reconfigurable omnidirectional soft robot based on caterpillar locomotion is described. The robot is composed of nine modules arranged as a three by three matrix and the length of this matrix is 154 mm. The robot propagates a traveling wave inspired by caterpillar locomotion, and it has all three degrees of freedom on a plane (X, Y, and rotation). The speed of the robot is about 18.5 m/h (two body lengths per minute) and it can rotate at a speed of 1.63°/s. The modules have neodymium-iron-boron (NdFeB) magnets embedded and can be easily replaced or combined into other configurations. Two different configurations are presented to demonstrate the possibilities of the modular structure: (1) by removing some modules, the omnidirectional robot can be reassembled into a form that can crawl in a pipe and (2) two omnidirectional robots can crawl close to each other and be assembled automatically into a bigger omnidirectional robot. Omnidirectional motion is important for soft robots to explore unstructured environments. The modular structure gives the soft robot the ability to cope with the challenges of different environments and tasks.

  10. SACFIR: SDN-Based Application-Aware Centralized Adaptive Flow Iterative Reconfiguring Routing Protocol for WSNs.

    Science.gov (United States)

    Aslam, Muhammad; Hu, Xiaopeng; Wang, Fan

    2017-12-13

    Smart reconfiguration of a dynamic networking environment is offered by the central control of Software-Defined Networking (SDN). Centralized SDN-based management architectures are capable of retrieving global topology intelligence and decoupling the forwarding plane from the control plane. Routing protocols developed for conventional Wireless Sensor Networks (WSNs) utilize limited iterative reconfiguration methods to optimize environmental reporting. However, the challenging networking scenarios of WSNs involve a performance overhead due to constant periodic iterative reconfigurations. In this paper, we propose the SDN-based Application-aware Centralized adaptive Flow Iterative Reconfiguring (SACFIR) routing protocol with the centralized SDN iterative solver controller to maintain the load-balancing between flow reconfigurations and flow allocation cost. The proposed SACFIR's routing protocol offers a unique iterative path-selection algorithm, which initially computes suitable clustering based on residual resources at the control layer and then implements application-aware threshold-based multi-hop report transmissions on the forwarding plane. The operation of the SACFIR algorithm is centrally supervised by the SDN controller residing at the Base Station (BS). This paper extends SACFIR to SDN-based Application-aware Main-value Centralized adaptive Flow Iterative Reconfiguring (SAMCFIR) to establish both proactive and reactive reporting. The SAMCFIR transmission phase enables sensor nodes to trigger direct transmissions for main-value reports, while in the case of SACFIR, all reports follow computed routes. Our SDN-enabled proposed models adjust the reconfiguration period according to the traffic burden on sensor nodes, which results in heterogeneity awareness, load-balancing and application-specific reconfigurations of WSNs. Extensive experimental simulation-based results show that SACFIR and SAMCFIR yield the maximum scalability, network lifetime and stability

  11. SACFIR: SDN-Based Application-Aware Centralized Adaptive Flow Iterative Reconfiguring Routing Protocol for WSNs

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam

    2017-12-01

    Full Text Available Smart reconfiguration of a dynamic networking environment is offered by the central control of Software-Defined Networking (SDN. Centralized SDN-based management architectures are capable of retrieving global topology intelligence and decoupling the forwarding plane from the control plane. Routing protocols developed for conventional Wireless Sensor Networks (WSNs utilize limited iterative reconfiguration methods to optimize environmental reporting. However, the challenging networking scenarios of WSNs involve a performance overhead due to constant periodic iterative reconfigurations. In this paper, we propose the SDN-based Application-aware Centralized adaptive Flow Iterative Reconfiguring (SACFIR routing protocol with the centralized SDN iterative solver controller to maintain the load-balancing between flow reconfigurations and flow allocation cost. The proposed SACFIR’s routing protocol offers a unique iterative path-selection algorithm, which initially computes suitable clustering based on residual resources at the control layer and then implements application-aware threshold-based multi-hop report transmissions on the forwarding plane. The operation of the SACFIR algorithm is centrally supervised by the SDN controller residing at the Base Station (BS. This paper extends SACFIR to SDN-based Application-aware Main-value Centralized adaptive Flow Iterative Reconfiguring (SAMCFIR to establish both proactive and reactive reporting. The SAMCFIR transmission phase enables sensor nodes to trigger direct transmissions for main-value reports, while in the case of SACFIR, all reports follow computed routes. Our SDN-enabled proposed models adjust the reconfiguration period according to the traffic burden on sensor nodes, which results in heterogeneity awareness, load-balancing and application-specific reconfigurations of WSNs. Extensive experimental simulation-based results show that SACFIR and SAMCFIR yield the maximum scalability, network lifetime

  12. Graphene-based Yagi-Uda antenna with reconfigurable radiation patterns

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yongle, E-mail: wuyongle138@gmail.com; Qu, Meijun; Jiao, Lingxiao; Liu, Yuanan [School of Electronic Engineering, Beijing Key Laboratory of Work Safety Intelligent Monitoring, Beijing University of Posts and Telecommunications, P. O. Box. 282, Beijing, 100876 (China); Ghassemlooy, Zabih [Optical Communications Research Group, NCRLab, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, NE1 8ST (United Kingdom)

    2016-06-15

    This paper presents a radiation pattern reconfigurable Yagi-Uda antenna based on graphene operating at terahertz frequencies. The antenna can be reconfigured to change the main beam pattern into two or four different radiation directions. The proposed antenna consists of a driven dipole radiation conductor, parasitic strips and embedded graphene. The hybrid graphene-metal implementation enables the antenna to have dynamic surface conductivity, which can be tuned by changing the chemical potentials. Therefore, the main beam direction, the resonance frequency, and the front-to-back ratio of the proposed antenna can be controlled by tuning the chemical potentials of the graphene embedded in different positions. The proposed two-beam reconfigurable Yagi-Uda antenna can achieve excellent unidirectional symmetrical radiation pattern with the front-to-back ratio of 11.9 dB and the10-dB impedance bandwidth of 15%. The different radiation directivity of the two-beam reconfigurable antenna can be achieved by controlling the chemical potentials of the graphene embedded in the parasitic stubs. The achievable peak gain of the proposed two-beam reconfigurable antenna is about 7.8 dB. Furthermore, we propose a four-beam reconfigurable Yagi-Uda antenna, which has stable reflection-coefficient performance although four main beams in reconfigurable cases point to four totally different directions. The corresponding peak gain, front-to-back ratio, and 10-dB impedance bandwidth of the four-beam reconfigurable antenna are about 6.4 dB, 12 dB, and 10%, respectively. Therefore, this novel design method of reconfigurable antennas is extremely promising for beam-scanning in terahertz and mid-infrared plasmonic devices and systems.

  13. A Web-Based Integration Procedure for the Development of Reconfigurable Robotic Work-Cells

    Directory of Open Access Journals (Sweden)

    Paulo Ferreira

    2013-07-01

    Full Text Available Concepts related to the development of reconfigurable manufacturing systems (RMS and methodologies to provide the best practices in the processing industry and factory automation, such as system integration and web-based technology, are major issues in designing next-generation manufacturing systems (NGMS. Adaptable and integrable devices are crucial for the success of NGMS. In robotic cells the integration of manufacturing components is essential to accelerate system adaptability. Sensors, control architectures and communication technologies have contributed to achieving further agility in reconfigurable factories. In this work a web-based robotic cell integration procedure is proposed to aid the identification of reconfigurable issues and requirements. This methodology is applied to an industrial robot manipulator to enhance system flexibility towards the development of a reconfigurable robotic platform.

  14. Design and Fabrication of a Reconfigurable MEMS-Based Antenna

    KAUST Repository

    Martinez, Miguel Angel Galicia

    2011-01-01

    According to the high gain obtained in a lossy silicon substrate and the compatibility of the custom MEMS process with the state of the art standard CMOS process, it is believed that the design of this antenna can lead to efficient and low cost reconfigurable millimeter-wave System-on-Chip (SoC) solution.

  15. Development of electrothermal actuation based planar variable optical attenuators (VOAs)

    International Nuclear Information System (INIS)

    Lee, Chengkuo; Yeh, J Andrew

    2006-01-01

    Several sorts of MEMS (Microelectromechanical Systems) based have been demonstrated by using electrostatic actuation scheme up to date. The comb drive and parallel plate are the two most common electrostatic actuators that have been well studied in variable optical attenuator (VOA) applications. In addition to the known retro-reflection type of optical attenuation being realized by our new devices driven by electrothermal actuators in present study, a novel planar tilted mirror with rotational and translation moving capability is proposed by using electrothermal actuators as well. Using electrothermal actuators to provide said planar tilted mirror with rotational and translational displacement has granted us a more efficient way to perform the light attenuation for in-plane structure. The static and transient characteristics of devices operated at ambient room temperature environment show good repeatability and stability

  16. Actuators, transducers and motors based on giant magnetostrictive materials

    Energy Technology Data Exchange (ETDEWEB)

    Claeyssen, F.; Lhermet, N.; Le Letty, R. [Cedrat Recherche, Meylan (France); Bouchilloux, P. [Magsoft Corporation, 1223 People`s Avenue, New York 12180 (United States)

    1997-08-01

    Rare earth-iron magnetostrictive alloys, especially Terfenol-D, feature ``giant`` magnetostrains: static strains of 1000-2000 ppm and dynamic strains of 3500 ppm are reported. These strains permit building various actuating devices (actuators, transducers, motors) both at macro and micro scale. The object of the paper is to recall adapted design methods, especially finite element methods such as ATILA, and to review these different kinds of devices studied at Cedrat Recherche, providing both up-dated experimental and numerical results. The presented devices will include several large displacement longitudinal and shear actuators biased using permanent magnets and used either as characterisation devices or as electromechanical actuators (for active damping, for sonar transducers..), a 1 kHz 4 kW Tonpilz-type sonar transducer called the tripode, a 2 N m torque rotating multi-mode motor, a torsion based drift free micro actuator and a wireless linear micromotor. (orig.)

  17. Development of a metal-based composite actuator

    Science.gov (United States)

    Asanuma, Hiroshi; Haga, Osamu; Ishii, Toshio; Kurihara, Haruki; Ohira, Junichiro; Hakoda, Genji

    2000-06-01

    This paper describes a basic concept and elemental developments to realize a metal based composite actuator to be used for smart structures. In this study, CFRP prepreg was laminated on aluminum plate to develop an actuator and this laminate could perform unidirectional actuation. SiC continuous fiber/Al composite thin plate could also be used for form a modified type of actuator instead of using CFRP. As sensors to be embedded in this actuator, the following ones wee developed. (1) A pre-notched optical fiber filament could be embedded in aluminum matrix without fracture by the interphase forming/bonding method with copper insert and could be fractured in it at the notch, which enabled forming of an optical interference type strain sensor. (2) Nickel wire could be uniformly oxidized and embedded in aluminum matrix without fracture, which could successfully work as a temperature sensor and a strain sensor.

  18. Iridium oxide as actuator material for the ISFET-based sensor-actuator system

    NARCIS (Netherlands)

    Olthuis, Wouter; Bomer, Johan G.; Bergveld, Piet; van der Linden, W.E.; Bos, M.; Bos, M.

    1991-01-01

    Acid or base concentrations can be determined by performing an acid-base titration with Coulometrically generated OH- or H+ ions at a noble-metal actuator electrode in close proximity to the pH-sensitive gate of an ISFET. The ISFET is used as the indicator electrode to detect the equivalence point

  19. CAMAC based Test Signal Generator using Re-configurable device

    International Nuclear Information System (INIS)

    Sharma, Atish; Raval, Tushar; Srivastava, Amit K; Reddy, D Chenna

    2010-01-01

    There are many different types of signal generators, with different purposes and applications (and at varying levels of expense). In general, no device is suitable for all possible applications. Hence the selection of signal generator is as per requirements. For SST-1 Data Acquisition System requirements, we have developed a CAMAC based Test Signal Generator module using Re-configurable device (CPLD). This module is based on CAMAC interface but can be used for testing both CAMAC and PXI Data Acquisition Systems in SST-1 tokamak. It can also be used for other similar applications. Unlike traditional signal generators, which are embedded hardware, it is a flexible hardware unit, programmable through Graphical User Interface (GUI) developed in LabVIEW application development tool. The main aim of this work is to develop a signal generator for testing our data acquisition interface for a large number of channels simultaneously. The module front panel has various connectors like LEMO and D type connectors for signal interface. The module can be operated either in continuous signal generation mode or in triggered mode depending upon application. This can be done either by front panel switch or through CAMAC software commands (for remote operation). Similarly module reset and trigger generation operation can be performed either through front panel push button switch or through software CAMAC commands. The module has the facility to accept external TTL level trigger and clock through LEMO connectors. The module can also generate trigger and the clock signal, which can be delivered to other devices through LEMO connectors. The module generates two types of signals: Analog and digital (TTL level). The analog output (single channel) is generated from Digital to Analog Converter through CPLD for various types of waveforms like Sine, Square, Triangular and other wave shape that can vary in amplitude as well as in frequency. The module is quite useful to test up to 32 channels

  20. Functional verification of dynamically reconfigurable FPGA-based systems

    CERN Document Server

    Gong, Lingkan

    2015-01-01

    This book analyzes the challenges in verifying Dynamically Reconfigurable Systems (DRS) with respect to the user design and the physical implementation of such systems. The authors describe the use of a simulation-only layer to emulate the behavior of target FPGAs and accurately model the characteristic features of reconfiguration. Readers are enabled with this simulation-only layer to maintain verification productivity by abstracting away the physical details of the FPGA fabric.  Two implementations of the simulation-only layer are included: Extended ReChannel is a SystemC library that can be used to check DRS designs at a high level; ReSim is a library to support RTL simulation of a DRS reconfiguring both its logic and state. Through a number of case studies, the authors demonstrate how their approach integrates seamlessly with existing, mainstream DRS design flows and with well-established verification methodologies such as top-down modeling and coverage-driven verification. Provides researchers with an i...

  1. Fast-Response Electrostatic Actuator Based on Nano-Gap

    Directory of Open Access Journals (Sweden)

    Edward Kostsov

    2017-03-01

    Full Text Available The possibility of constructing new high-performance electrostatic fast actuators based on energy transformation in nanometer gaps is considered. The construction and the properties of the operation of such devices as well as their typical parameters are described. The drives are based on ferroelectrics with high values of dielectric permittivity (above 1000. They can be constructed using microelectronic technology. It is demonstrated that the actuators are capable of maintaining forces with a specific density up to 106 N/m2 and up to 100–1000 N in real devices for 10–100 µs. Experimental research results of such actuators are presented.

  2. Short-Term Load Forecasting Based Automatic Distribution Network Reconfiguration: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Huaiguang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ding, Fei [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yingchen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jiang, Huaiguang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ding, Fei [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yingchen [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-07-26

    In the traditional dynamic network reconfiguration study, the optimal topology is determined at every scheduled time point by using the real load data measured at that time. The development of load forecasting technique can provide accurate prediction of load power that will happen in future time and provide more information about load changes. With the inclusion of load forecasting, the optimal topology can be determined based on the predicted load conditions during the longer time period instead of using the snapshot of load at the time when the reconfiguration happens, and thus it can provide information to the distribution system operator (DSO) to better operate the system reconfiguration to achieve optimal solutions. Thus, this paper proposes a short-term load forecasting based approach for automatically reconfiguring distribution systems in a dynamic and pre-event manner. Specifically, a short-term and high-resolution distribution system load forecasting approach is proposed with support vector regression (SVR) based forecaster and parallel parameters optimization. And the network reconfiguration problem is solved by using the forecasted load continuously to determine the optimal network topology with the minimum loss at the future time. The simulation results validate and evaluate the proposed approach.

  3. Plant-based torsional actuator with memory

    Science.gov (United States)

    Nayomi Plaza; Samuel L. Zelinka; Don S. Stone; Joseph E. Jakes

    2013-01-01

    A bundle of a few loblolly pine (Pinus taeda) cells are moisture-activated torsional actuators that twist multiple revolutions per cm length in direct proportion to moisture content. The bundles generate 10 N m kg􀀀1 specific torque during both twisting and untwisting, which is higher than an electric motor. Additionally, the bundles exhibit a moisture-...

  4. Tough nanocomposite ionogel-based actuator exhibits robust performance.

    Science.gov (United States)

    Liu, Xinhua; He, Bin; Wang, Zhipeng; Tang, Haifeng; Su, Teng; Wang, Qigang

    2014-10-20

    Ionogel electrolytes can be fabricated for electrochemical actuators with many desirable advantages, including direct low-voltage control in air, high electrochemical and thermal stability, and complete silence during actuation. However, the demands for active actuators with above features and load-driving ability remain a challenge; much work is necessary to enhance the mechanical strength of electrolyte materials. Herein, we describe a cross-linked supramolecular approach to prepare tough nanocomposite gel electrolytes from HEMA, BMIMBF4, and TiO2 via self-initiated UV polymerization. The tough and stable ionogels are emerging to fabricate electric double-layer capacitor-like soft actuators, which can be driven by electrically induced ion migration. The ionogel-based actuator shows a displacement response of 5.6 mm to the driving voltage of 3.5 V. After adding the additional mass weight of the same as the actuator, it still shows a large displacement response of 3.9 mm. Furthermore, the actuator can not only work in harsh temperature environments (100°C and -10°C) but also realize the goal of grabbing an object by adjusting the applied voltage.

  5. Short-Term Load Forecasting-Based Automatic Distribution Network Reconfiguration

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Huaiguang [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ding, Fei [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yingchen [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-23

    In a traditional dynamic network reconfiguration study, the optimal topology is determined at every scheduled time point by using the real load data measured at that time. The development of the load forecasting technique can provide an accurate prediction of the load power that will happen in a future time and provide more information about load changes. With the inclusion of load forecasting, the optimal topology can be determined based on the predicted load conditions during a longer time period instead of using a snapshot of the load at the time when the reconfiguration happens; thus, the distribution system operator can use this information to better operate the system reconfiguration and achieve optimal solutions. This paper proposes a short-term load forecasting approach to automatically reconfigure distribution systems in a dynamic and pre-event manner. Specifically, a short-term and high-resolution distribution system load forecasting approach is proposed with a forecaster based on support vector regression and parallel parameters optimization. The network reconfiguration problem is solved by using the forecasted load continuously to determine the optimal network topology with the minimum amount of loss at the future time. The simulation results validate and evaluate the proposed approach.

  6. Reconfiguring waveguide-gratings-based M-signature codecs to enhance OCDMA network confidentiality

    Science.gov (United States)

    Huang, Jen-Fa; Chen, Kai-Sheng; Lin, Ying-Chen; Li, Chung-Yu

    2014-02-01

    A reconfiguration scheme based on composite signature codes over waveguide-gratings-based optical code-division multiple-access (OCDMA) network coder/decoders (codecs) is proposed in the paper. By using central control node to monitor network traffic condition and reconfigure the composite signature codes made up of maximal-length sequence (M-sequence) component codes and random changing the signature codes assigned for each user to improve the confidentiality performance in an OCDMA system. The proposed scheme is analyzed with some practical eavesdroppers' attacks.

  7. SmartCell: An Energy Efficient Coarse-Grained Reconfigurable Architecture for Stream-Based Applications

    Directory of Open Access Journals (Sweden)

    Liang Cao

    2009-01-01

    Full Text Available This paper presents SmartCell, a novel coarse-grained reconfigurable architecture, which tiles a large number of processor elements with reconfigurable interconnection fabrics on a single chip. SmartCell is able to provide high performance and energy efficient processing for stream-based applications. It can be configured to operate in various modes, such as SIMD, MIMD, and systolic array. This paper describes the SmartCell architecture design, including processing element, reconfigurable interconnection fabrics, instruction and control process, and configuration scheme. The SmartCell prototype with 64 PEs is implemented using 0.13  m CMOS standard cell technology. The core area is about 8.5  , and the power consumption is about 1.6 mW/MHz. The performance is evaluated through a set of benchmark applications, and then compared with FPGA, ASIC, and two well-known reconfigurable architectures including RaPiD and Montium. The results show that the SmartCell can bridge the performance and flexibility gap between ASIC and FPGA. It is also about 8% and 69% more energy efficient than Montium and RaPiD systems for evaluated benchmarks. Meanwhile, SmartCell can achieve 4 and 2 times more throughput gains when comparing with Montium and RaPiD, respectively. It is concluded that SmartCell system is a promising reconfigurable and energy efficient architecture for stream processing.

  8. Fpga-based control of piezoelectric actuators

    Directory of Open Access Journals (Sweden)

    Juhász László

    2011-01-01

    Full Text Available In many industrial applications like semiconductor production and optical inspection systems, the availability of positioning systems capable to follow trajectory paths in the range of several centimetres, featuring at the same time a nanometre-range precision, is demanding. Pure piezoelectric stages and standard positioning systems with motor and spindle are not able to meet such requirements, because of the small operation range and inadequacies like backlash and friction. One concept for overcoming these problems consists of a hybrid positioning system built through the integration of a DC-drive in series with a piezoelectric actuator. The wide range of potential applications enables a considerable market potential for such an actuator, but due to the high variety of possible positioned objects and dynamic requirements, the required control complexity may be significant. In this paper, a real-time capable state-space control concept for the piezoelectric actuators, embedded in such a hybrid micropositioning system, is presented. The implementation of the controller together with a real-time capable hysteresis compensation measure is performed using a low-budget FPGA-board, whereas the superimposed integrated controller is realized with a dSPACE RCP-system. The advantages of the designed control over a traditional proportional-integral control structure are proven through experimental results using a commercially available hybrid micropositioning system. Positioning results by different dynamic requirements featuring positioning velocities from 1 μm/s up to 5 cm/s are given.

  9. Evaluation of a reconfigurable portable instrument for copper determination based on luminescent carbon dots.

    Science.gov (United States)

    Salinas-Castillo, Alfonso; Morales, Diego P; Lapresta-Fernández, Alejandro; Ariza-Avidad, María; Castillo, Encarnación; Martínez-Olmos, Antonio; Palma, Alberto J; Capitan-Vallvey, Luis Fermin

    2016-04-01

    A portable reconfigurable platform for copper (Cu(II)) determination based on luminescent carbon dot (Cdots) quenching is described. The electronic setup consists of a light-emitting diode (LED) as the carbon dot optical exciter and a photodiode as a light-to-current converter integrated in the same instrument. Moreover, the overall analog conditioning is simply performed with one integrated solution, a field-programmable analog array (FPAA), which makes it possible to reconfigure the filter and gain stages in real time. This feature provides adaptability to use the platform as an analytical probe for carbon dots coming from different batches with some variations in luminescence characteristics. The calibration functions obtained that fit a modified Stern-Volmer equation were obtained using luminescence signals from Cdots quenching by Cu(II). The analytical applicability of the reconfigurable portable instrument for Cu(II) using Cdots has been successfully demonstrated in tap water analysis.

  10. Market-based multiagent system for reconfiguration of shipboard power systems

    International Nuclear Information System (INIS)

    Huang, Kai; Srivastava, Sanjeev K.; Cartes, David A.; Sun, Li-Hsiang

    2009-01-01

    On ships, the electric shipboard power system (SPS) supplies electrical power to critical functions such as navigation, communication, emergency systems, and in the case of warships, weapon systems. During ship operation, some parts of the SPS may become unavailable due to damage, fault, or maintenance. For the survivability and reliability of ships, it is desired to make the SPS highly reconfigurable. This paper presents a market-based multiagent system (MAS) for the reconfiguration of radial SPS. Radial SPSs are found on majority of ships. In the proposed MAS, each agent only communicates with its neighbor agents to make the system work in a fully decentralized manner. The MAS is implemented using Java Agent Development Framework (JADE), which is fully implemented in Java and compliant with Foundation of Intelligent Physical Agents (FIPA). An SPS with two generators and four loads is used for testing the proposed MAS. The results show the proposed MAS can successfully reconfigure a radial SPS. (author)

  11. Reconfigurable Magneto-Electric Dipole Antennas for Base Stations in Modern Wireless Communication Systems

    Directory of Open Access Journals (Sweden)

    Lei Ge

    2018-01-01

    Full Text Available Magneto-electric (ME dipole antennas, with the function of changing the antenna characteristics, such as frequency, polarization, or radiation patterns, are reviewed in this paper. The reconfigurability is achieved by electrically altering the states of diodes or varactors to change the surface currents distributions or reflector size of the antenna. The purpose of the designs is to obtain agile antenna characteristics together with good directive radiation performances, such as low cross-polarization level, high front-to-back ratio, and stable gain. By reconfiguring the antenna capability to support more than one wireless frequency standard, switchable polarizations, or cover tunable areas, the reconfigurable ME dipole antennas are able to switch functionality as the mission changes. Therefore, it can help increase the communication efficiency and reduce the construction cost. This shows very attractive features in base station antennas of modern wireless communication applications.

  12. Optically Controlled Reconfigurable Antenna Array Based on E-Shaped Elements

    Directory of Open Access Journals (Sweden)

    Arismar Cerqueira Sodré Junior

    2014-01-01

    Full Text Available This work presents the development of optically controlled reconfigurable antenna arrays. They are based on two patch elements with E-shaped slots, a printed probe, and a photoconductive switch made from an intrinsic silicon die. Numerical simulations and experiments have been shown to be in agreement, and both demonstrate that the frequency response of the antenna arrays can be efficiently reconfigured over two different frequency ISM bands, namely, 2.4 and 5 GHz. A measured gain of 12.5 dBi has been obtained through the use of two radiating elements printed in a low-cost substrate and a dihedral corner reflector.

  13. Design of millimeter-wave MEMS-based reconfigurable front-end circuits using the standard CMOS technology

    International Nuclear Information System (INIS)

    Chang, Chia-Chan; Hsieh, Sheng-Chi; Chen, Chien-Hsun; Huang, Chin-Yen; Yao, Chun-Han; Lin, Chun-Chi

    2011-01-01

    This paper describes the designs of three reconfigurable CMOS-MEMS front-end components for V-/W-band applications. The suspended MEMS structure is released through post-CMOS micromachining. To achieve circuit reconfigurability, dual-state and multi-state fishbone-beam-drive actuators are proposed herein. The reconfigurable bandstop is fabricated in a 0.35 µm CMOS process with the chip size of 0.765 × 0.98 mm 2 , showing that the stop-band frequency can be switched from 60 to 50 GHz with 40 V actuation voltage. The measured isolation is better than 38 dB at 60 GHz and 34 dB at 50 GHz, respectively. The bandpass filter-integrated single-pole single-throw switch, using the 0.18 µm CMOS process, demonstrates that insertion loss and return loss are better than 6.2 and 15 dB from 88 to 100 GHz in the on-state, and isolation is better than 21 dB in the off-state with an actuation voltage of 51 V. The chip size is 0.7 × 1.04 mm 2 . The third component is a reconfigurable slot antenna fabricated in a 0.18 µm CMOS process with the chip size of 1.2 × 1.2 mm 2 . By utilizing the multi-state actuators, the frequencies of this antenna can be switched to 43, 47, 50.5, 54, 57.5 GHz with return loss better than 20 dB. Those circuits demonstrate good RF performance and are relatively compact by employing several size miniaturizing techniques, thereby enabling a great potential for the future single-chip transceiver.

  14. More Insight of Piezoelectric-based Synthetic Jet Actuators

    Science.gov (United States)

    Housley, Kevin; Amitay, Michael

    2016-11-01

    Increased understanding of the internal flow of piezoelectric-based synthetic jet actuators is needed for the development of specialized actuator cavity geometries to increase jet momentum coefficients and tailor acoustic resonant frequencies. Synthetic jet actuators can benefit from tuning of the structural resonant frequency of the piezoelectric diaphragm(s) and the acoustic resonant frequency of the actuator cavity such that they experience constructive coupling. The resulting coupled behavior produces increased jet velocities. The ability to design synthetic jet actuators to operate with this behavior at select driving frequencies allows for them to be better used in flow control applications, which sometimes require specific jet frequencies in order to utilize the natural instabilities of a given flow field. A parametric study of varying actuator diameters was conducted to this end. Phase-locked data were collected on the jet velocity, the cavity pressure at various locations, and the three-dimensional deformation of the surface of the diaphragm. These results were compared to previous analytical work on the interaction between the structural resonance of the diaphragm and the acoustic resonance of the cavity. Funded by the Boeing Company.

  15. Design-based modeling of magnetically actuated soft diaphragm materials

    Science.gov (United States)

    Jayaneththi, V. R.; Aw, K. C.; McDaid, A. J.

    2018-04-01

    Magnetic polymer composites (MPC) have shown promise for emerging biomedical applications such as lab-on-a-chip and implantable drug delivery. These soft material actuators are capable of fast response, large deformation and wireless actuation. Existing MPC modeling approaches are computationally expensive and unsuitable for rapid design prototyping and real-time control applications. This paper proposes a macro-scale 1-DOF model capable of predicting force and displacement of an MPC diaphragm actuator. Model validation confirmed both blocked force and displacement can be accurately predicted in a variety of working conditions i.e. different magnetic field strengths, static/dynamic fields, and gap distances. The contribution of this work includes a comprehensive experimental investigation of a macro-scale diaphragm actuator; the derivation and validation of a new phenomenological model to describe MPC actuation; and insights into the proposed model’s design-based functionality i.e. scalability and generalizability in terms of magnetic filler concentration and diaphragm diameter. Due to the lumped element modeling approach, the proposed model can also be adapted to alternative actuator configurations, and thus presents a useful tool for design, control and simulation of novel MPC applications.

  16. Model-based design and experimental verification of a monitoring concept for an active-active electromechanical aileron actuation system

    Science.gov (United States)

    Arriola, David; Thielecke, Frank

    2017-09-01

    Electromechanical actuators have become a key technology for the onset of power-by-wire flight control systems in the next generation of commercial aircraft. The design of robust control and monitoring functions for these devices capable to mitigate the effects of safety-critical faults is essential in order to achieve the required level of fault tolerance. A primary flight control system comprising two electromechanical actuators nominally operating in active-active mode is considered. A set of five signal-based monitoring functions are designed using a detailed model of the system under consideration which includes non-linear parasitic effects, measurement and data acquisition effects, and actuator faults. Robust detection thresholds are determined based on the analysis of parametric and input uncertainties. The designed monitoring functions are verified experimentally and by simulation through the injection of faults in the validated model and in a test-rig suited to the actuation system under consideration, respectively. They guarantee a robust and efficient fault detection and isolation with a low risk of false alarms, additionally enabling the correct reconfiguration of the system for an enhanced operational availability. In 98% of the performed experiments and simulations, the correct faults were detected and confirmed within the time objectives set.

  17. Photonics-assisted wireless link based on mm-wave reconfigurable antennas

    DEFF Research Database (Denmark)

    Feliciano daCosta, Igor; Cerqueira Sodré, Arismar; Rodriguez Páez, Juan Sebastián

    2017-01-01

    The authors report a novel concept for photonics-assisted and broadband optical-wireless indoor networks based on optically-controlled reconfigurable antenna arrays (OCRAAs) and photonic down conversion (PDC) techniques, operating in the 28 and 38 GHz frequency bands. The antenna bandwidth is opt...... for access networks in the mm-wave frequency range....

  18. Reconfigurable OR and XOR logic gates based on dual responsive on-off-on micromotors

    Science.gov (United States)

    Dong, Yonggang; Liu, Mei; Zhang, Hui; Dong, Bin

    2016-04-01

    In this study, we report a hemisphere-like micromotor. Intriguingly, the micromotor exhibits controllable on-off-on motion, which can be actuated by two different external stimuli (UV and NH3). Moreover, the moving direction of the micromotor can be manipulated by the direction in which UV and NH3 are applied. As a result, the motion accelerates when both stimuli are applied in the same direction and decelerates when the application directions are opposite to each other. More interestingly, the dual stimuli responsive micromotor can be utilized as a reconfigurable logic gate with UV and NH3 as the inputs and the motion of the micromotor as the output. By controlling the direction of the external stimuli, OR and XOR dual logic functions can be realized.In this study, we report a hemisphere-like micromotor. Intriguingly, the micromotor exhibits controllable on-off-on motion, which can be actuated by two different external stimuli (UV and NH3). Moreover, the moving direction of the micromotor can be manipulated by the direction in which UV and NH3 are applied. As a result, the motion accelerates when both stimuli are applied in the same direction and decelerates when the application directions are opposite to each other. More interestingly, the dual stimuli responsive micromotor can be utilized as a reconfigurable logic gate with UV and NH3 as the inputs and the motion of the micromotor as the output. By controlling the direction of the external stimuli, OR and XOR dual logic functions can be realized. Electronic supplementary information (ESI) available: Fig. S1-S6 and Videos S1-S5. See DOI: 10.1039/c6nr00752j

  19. Metallic molybdenum disulfide nanosheet-based electrochemical actuators

    Science.gov (United States)

    Acerce, Muharrem; Akdoğan, E. Koray; Chhowalla, Manish

    2017-09-01

    Actuators that convert electrical energy to mechanical energy are useful in a wide variety of electromechanical systems and in robotics, with applications such as steerable catheters, adaptive wings for aircraft and drag-reducing wind turbines. Actuation systems can be based on various stimuli, such as heat, solvent adsorption/desorption, or electrochemical action (in systems such as carbon nanotube electrodes, graphite electrodes, polymer electrodes and metals). Here we demonstrate that the dynamic expansion and contraction of electrode films formed by restacking chemically exfoliated nanosheets of two-dimensional metallic molybdenum disulfide (MoS2) on thin plastic substrates can generate substantial mechanical forces. These films are capable of lifting masses that are more than 150 times that of the electrode over several millimetres and for hundreds of cycles. Specifically, the MoS2 films are able to generate mechanical stresses of about 17 megapascals—higher than mammalian muscle (about 0.3 megapascals) and comparable to ceramic piezoelectric actuators (about 40 megapascals)—and strains of about 0.6 per cent, operating at frequencies up to 1 hertz. The actuation performance is attributed to the high electrical conductivity of the metallic 1T phase of MoS2 nanosheets, the elastic modulus of restacked MoS2 layers (2 to 4 gigapascals) and fast proton diffusion between the nanosheets. These results could lead to new electrochemical actuators for high-strain and high-frequency applications.

  20. Large displacement vertical translational actuator based on piezoelectric thin films.

    Science.gov (United States)

    Qiu, Zhen; Pulskamp, Jeffrey S; Lin, Xianke; Rhee, Choong-Ho; Wang, Thomas; Polcawich, Ronald G; Oldham, Kenn

    2010-07-01

    A novel vertical translational microactuator based on thin-film piezoelectric actuation is presented, using a set of four compound bend-up/bend-down unimorphs to produce translational motion of a moving platform or stage. The actuation material is a chemical-solution deposited lead-zirconate-titanate (PZT) thin film. Prototype designs have shown as much as 120 μ m of static displacement, with 80-90 μ m displacements being typical, using four 920 μ m long by 70 μ m legs. Analytical models are presented that accurately describe nonlinear behavior in both static and dynamic operation of prototype stages when the dependence of piezoelectric coefficients on voltage is known. Resonance of the system is observed at a frequency of 200 Hz. The large displacement and high bandwidth of the actuators at low-voltage and low-power levels should make them useful to a variety of optical applications, including endoscopic microscopy.

  1. Nonlinear Model-Based Fault Detection for a Hydraulic Actuator

    NARCIS (Netherlands)

    Van Eykeren, L.; Chu, Q.P.

    2011-01-01

    This paper presents a model-based fault detection algorithm for a specific fault scenario of the ADDSAFE project. The fault considered is the disconnection of a control surface from its hydraulic actuator. Detecting this type of fault as fast as possible helps to operate an aircraft more cost

  2. Nonlinear dispersion-based incoherent photonic processing for microwave pulse generation with full reconfigurability.

    Science.gov (United States)

    Bolea, Mario; Mora, José; Ortega, Beatriz; Capmany, José

    2012-03-12

    A novel all-optical technique based on the incoherent processing of optical signals using high-order dispersive elements is analyzed for microwave arbitrary pulse generation. We show an approach which allows a full reconfigurability of a pulse in terms of chirp, envelope and central frequency by the proper control of the second-order dispersion and the incoherent optical source power distribution, achieving large values of time-bandwidth product.

  3. A Web-Based Integration Procedure for the Development of Reconfigurable Robotic Work-Cells

    OpenAIRE

    Paulo Ferreira; Victoria Reyes; João Mestre

    2013-01-01

    Concepts related to the development of reconfigurable manufacturing systems (RMS) and methodologies to provide the best practices in the processing industry and factory automation, such as system integration and web-based technology, are major issues in designing next-generation manufacturing systems (NGMS). Adaptable and integrable devices are crucial for the success of NGMS. In robotic cells the integration of manufacturing components is essential to accelerate system adaptability. Sensors,...

  4. Theoretical and experimental study on active sound transmission control based on single structural mode actuation using point force actuators.

    Science.gov (United States)

    Sanada, Akira; Tanaka, Nobuo

    2012-08-01

    This study deals with the feedforward active control of sound transmission through a simply supported rectangular panel using vibration actuators. The control effect largely depends on the excitation method, including the number and locations of actuators. In order to obtain a large control effect at low frequencies over a wide frequency, an active transmission control method based on single structural mode actuation is proposed. Then, with the goal of examining the feasibility of the proposed method, the (1, 3) mode is selected as the target mode and a modal actuation method in combination with six point force actuators is considered. Assuming that a single input single output feedforward control is used, sound transmission in the case minimizing the transmitted sound power is calculated for some actuation methods. Simulation results showed that the (1, 3) modal actuation is globally effective at reducing the sound transmission by more than 10 dB in the low-frequency range for both normal and oblique incidences. Finally, experimental results also showed that a large reduction could be achieved in the low-frequency range, which proves the validity and feasibility of the proposed method.

  5. Photoredox-Based Actuation of an Artificial Molecular Muscle.

    Science.gov (United States)

    Liles, Kevin P; Greene, Angelique F; Danielson, Mary K; Colley, Nathan D; Wellen, Andrew; Fisher, Jeremy M; Barnes, Jonathan C

    2018-01-24

    The use of light to actuate materials is advantageous because it represents a cost-effective and operationally straightforward way to introduce energy into a stimuli-responsive system. Common strategies for photoinduced actuation of materials typically rely on light irradiation to isomerize azobenzene or spiropyran derivatives, or to induce unidirectional rotation of molecular motors incorporated into a 3D polymer network. Although interest in photoredox catalysis has risen exponentially in the past decade, there are far fewer examples where photoinduced electron transfer (PET) processes are employed to actuate materials. Here, a novel mode of actuation in a series of redox-responsive hydrogels doped with a visible-light-absorbing ruthenium-based photocatalyst is reported. The hydrogels are composed primarily of polyethylene glycol and low molar concentrations of a unimolecular electroactive polyviologen that is activated through a PET mechanism. The rate and degree of contraction of the hydrogels are measured over several hours while irradiating with blue light. Likewise, the change in mechanical properties-determined through oscillatory shear rheology experiments-is assessed as a function of polyviologen concentration. Finally, an artificial molecular muscle is fabricated using the best-performing hydrogel composition, and its ability to perform work, while irradiated, is demonstrated by lifting a small weight. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Programmable and functional electrothermal bimorph actuators based on large-area anisotropic carbon nanotube paper

    Science.gov (United States)

    Li, Qingwei; Liu, Changhong; Fan, Shoushan

    2018-04-01

    Electro-active polymer (EAP) actuators, such as electronic, ionic and electrothermal (ET) actuators, have become an important branch of next-generation soft actuators in bionic robotics. However, most reported EAP actuators could realize only simple movements, being restricted by the small area of flexible electrodes and simple designs. We prepared large-area flexible electrodes of high anisotropy, made of oriented carbon nanotube (CNT) paper, and carried out artful graphic designs and processing on the electrodes to make functional ET bimorph actuators which can realize large bending deformations (over 220°, curvature > 1.5 cm-1) and bionic movements driven by electricity. The anisotropy of CNT paper benefits electrode designs and multiform actuations for complex actuators. Based on the large-area CNT paper, more interesting and functional actuators can be designed and prepared which will have practical applications in the fields of artificial muscles, complicated actuations, and soft and bionic robotics.

  7. High speed vision processor with reconfigurable processing element array based on full-custom distributed memory

    Science.gov (United States)

    Chen, Zhe; Yang, Jie; Shi, Cong; Qin, Qi; Liu, Liyuan; Wu, Nanjian

    2016-04-01

    In this paper, a hybrid vision processor based on a compact full-custom distributed memory for near-sensor high-speed image processing is proposed. The proposed processor consists of a reconfigurable processing element (PE) array, a row processor (RP) array, and a dual-core microprocessor. The PE array includes two-dimensional processing elements with a compact full-custom distributed memory. It supports real-time reconfiguration between the PE array and the self-organized map (SOM) neural network. The vision processor is fabricated using a 0.18 µm CMOS technology. The circuit area of the distributed memory is reduced markedly into 1/3 of that of the conventional memory so that the circuit area of the vision processor is reduced by 44.2%. Experimental results demonstrate that the proposed design achieves correct functions.

  8. Implementing EW Receivers Based on Large Point Reconfigured FFT on FPGA Platforms

    Directory of Open Access Journals (Sweden)

    He Chen

    2011-12-01

    Full Text Available This paper presents design and implementation of digital receiver based on large point fast Fourier transform (FFT suitable for electronic warfare (EW applications. When implementing the FFT algorithm on field-programmable gate array (FPGA platforms, the primary goal is to maximize throughput and minimize area. This algorithm adopts two-dimension, parallel and pipeline stream mode and implements the reconfiguration of FFT's points. Moreover, a double-sequence-separation FFT algorithm has been implemented in order to achieve faster real time processing in broadband digital receivers. The performance of the hardware implementation on the FPGA platforms of broadband digital receivers has been analyzed in depth. It reaches the requirement of high-speed digital signal processing, and reveals the designing this kind of digital signal processing systems on FPGA platforms. Keywords: digital receivers, field programmable gate array (FPGA, fast Fourier transform (FFT, large point reconfigured, signal processing system.

  9. A road to practical dielectric elastomer actuators based robotics and mechatronics: discrete actuation

    Science.gov (United States)

    Plante, Jean-Sébastien; Devita, Lauren M.; Dubowsky, Steven

    2007-04-01

    Fundamental studies of Dielectric Elastomer Actuators (DEAs) using viscoelastic materials such as VHB 4905/4910 from 3M showed significant advantages at high stretch rates. The film's viscous forces increase actuator life and the short power-on times minimize energy losses through current leakage. This paper presents a design paradigm that exploits these fundamental properties of DEAs called discrete actuation. Discrete actuation uses DEAs at high stretch rates to change the states of robotic or mechatronic systems in discrete steps. Each state of the system is stable and can be maintained without actuator power. Discrete actuation can be used in robotic and mechatronic applications such as manipulation and locomotion. The resolution of such systems increases with the number of discrete states, 10 to 100 being sufficient for many applications. An MRI-guided needle positioning device for cancer treatments and a space exploration robot using hopping for locomotion are presented as examples of this concept.

  10. Reconfigurable Diodes Based on Vertical WSe2 Transistors with van der Waals Bonded Contacts.

    Science.gov (United States)

    Avsar, Ahmet; Marinov, Kolyo; Marin, Enrique Gonzalez; Iannaccone, Giuseppe; Watanabe, Kenji; Taniguchi, Takashi; Fiori, Gianluca; Kis, Andras

    2018-05-01

    New device concepts can increase the functionality of scaled electronic devices, with reconfigurable diodes allowing the design of more compact logic gates being one of the examples. In recent years, there has been significant interest in creating reconfigurable diodes based on ultrathin transition metal dichalcogenide crystals due to their unique combination of gate-tunable charge carriers, high mobility, and sizeable band gap. Thanks to their large surface areas, these devices are constructed under planar geometry and the device characteristics are controlled by electrostatic gating through rather complex two independent local gates or ionic-liquid gating. In this work, similar reconfigurable diode action is demonstrated in a WSe 2 transistor by only utilizing van der Waals bonded graphene and Co/h-BN contacts. Toward this, first the charge injection efficiencies into WSe 2 by graphene and Co/h-BN contacts are characterized. While Co/h-BN contact results in nearly Schottky-barrier-free charge injection, graphene/WSe 2 interface has an average barrier height of ≈80 meV. By taking the advantage of the electrostatic transparency of graphene and the different work-function values of graphene and Co/h-BN, vertical devices are constructed where different gate-tunable diode actions are demonstrated. This architecture reveals the opportunities for exploring new device concepts. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. An ultra-wideband pattern reconfigurable antenna based on graphene coating

    Science.gov (United States)

    Jiang, YanNan; Yuan, Rui; Gao, Xi; Wang, Jiao; Li, SiMin; Lin, Yi-Yu

    2016-11-01

    An ultra-wideband pattern reconfigurable antenna is proposed. The antenna is a dielectric coaxial hollow monopole with a cylindrical graphene-based impedance surface coating. It consists of a graphene sheet coated onto the inner surface of a cylindrical substrate and a set of independent polysilicon DC gating pads mounted on the outside of the cylindrical substrate. By changing the DC bias voltages to the different gating pads, the surface impedance of the graphene coating can be freely controlled. Due to the tunability of graphene's surface impedance, the radiation pattern of the proposed antenna can be reconfigured. A transmission line method is used to illustrate the physical mechanism of the proposed antenna. The results show that the proposed antenna can reconfigure its radiation pattern in the omnidirectional mode with the relative bandwidth of 58.5% and the directional mode over the entire azimuth plane with the relative bandwidth of 67%. Project supported by the National Natural Science Foundation of China (Grant Nos. 61661012, 61461016, and 61361005), the Natural Science Foundation of Guangxi, China (Grant Nos. 2015GXNSFBB139003 and 2014GXNSFAA118283), Program for Innovation Research Team of Guilin University of Electromagnetic Technology, China, and the Dean Project of Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing, China.

  12. Enhanced Particle Swarm Optimization-Based Feeder Reconfiguration Considering Uncertain Large Photovoltaic Powers and Demands

    Directory of Open Access Journals (Sweden)

    Ying-Yi Hong

    2014-01-01

    Full Text Available The Kyoto protocol recommended that industrialized countries limit their green gas emissions in 2012 to 5.2% below 1990 levels. Photovoltaic (PV arrays provide clear and sustainable renewable energy to electric power systems. Solar PV arrays can be installed in distribution systems of rural and urban areas, as opposed to wind-turbine generators, which cause noise in surrounding environments. However, a large PV array (several MW may incur several operation problems, for example, low power quality and reverse power. This work presents a novel method to reconfigure the distribution feeders in order to prevent the injection of reverse power into a substation connected to the transmission level. Moreover, a two-stage algorithm is developed, in which the uncertain bus loads and PV powers are clustered by fuzzy-c-means to gain representative scenarios; optimal reconfiguration is then achieved by a novel mean-variance-based particle swarm optimization. The system loss is minimized while the operational constraints, including reverse power and voltage variation, are satisfied due to the optimal feeder reconfiguration. Simulation results obtained from a 70-bus distribution system with 4 large PV arrays validate the proposed method.

  13. Controlling Tensegrity Robots through Evolution using Friction based Actuation

    Science.gov (United States)

    Kothapalli, Tejasvi; Agogino, Adrian K.

    2017-01-01

    Traditional robotic structures have limitations in planetary exploration as their rigid structural joints are prone to damage in new and rough terrains. In contrast, robots based on tensegrity structures, composed of rods and tensile cables, offer a highly robust, lightweight, and energy efficient solution over traditional robots. In addition tensegrity robots can be highly configurable by rearranging their topology of rods, cables and motors. However, these highly configurable tensegrity robots pose a significant challenge for locomotion due to their complexity. This study investigates a control pattern for successful locomotion in tensegrity robots through an evolutionary algorithm. A twelve-rod hardware model is rapidly prototyped to utilize a new actuation method based on friction. A web-based physics simulation is created to model the twelve-rod tensegrity ball structure. Square-waves are used as control policies for the actuators of the tensegrity structure. Monte Carlo trials are run to find the most successful number of amplitudes for the square-wave control policy. From the results, an evolutionary algorithm is implemented to find the most optimized solution for locomotion of the twelve-rod tensegrity structure. The software pattern coupled with the new friction based actuation method can serve as the basis for highly efficient tensegrity robots in space exploration.

  14. Adaptive deformable mirror : based on electromagnetic actuators

    NARCIS (Netherlands)

    Hamelinck, R.F.M.M.

    2010-01-01

    Refractive index variations in the earth's atmosphere cause wavefront aberrations and limit thereby the resolution in ground-based telescopes. With Adaptive Optics (AO) the temporally and spatially varying wavefront distortions can be corrected in real time. Most implementations in a ground based

  15. Fraction-based input modification for fast SMA-actuation

    NARCIS (Netherlands)

    Gaasbeek, Rolf; de Jager, Bram

    Shape Memory Alloy actuators are microactuators that are known for their high actuation-force and -strain. Limiting the application of Shape Memory Alloy actuators is the lack of suitable control algorithms that can deal with the highly non-linear dynamics of the actuator. The latter suffers from

  16. A reconfigurable all-optical VPN based on XGM effect of SOA in WDM PON

    Science.gov (United States)

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Tao; Su, Yikai

    2010-12-01

    We propose and experimentally demonstrate a reconfigurable all-optical VPN scheme enabling intercommunications among different ONUs in a WDM PON. Reconfiguration is realized by dynamically setting wavelength conversion of optical VPN signal using a SOA in the OLT.

  17. Reconfigurable pipelined sensing for image-based control

    NARCIS (Netherlands)

    Medina, R.; Stuijk, S.; Goswami, D.; Basten, T.

    2016-01-01

    Image-based control systems are becoming common in domains such as robotics, healthcare and industrial automation. Coping with a long sample period because of the latency of the image processing algorithm is an open challenge. Modern multi-core platforms allow to address this challenge by pipelining

  18. Comparison of microtweezers based on three lateral thermal actuator configurations

    Science.gov (United States)

    Luo, J. K.; Flewitt, A. J.; Spearing, S. M.; Fleck, N. A.; Milne, W. I.

    2005-06-01

    Thermal actuator-based microtweezers with three different driving configurations have been designed, fabricated and characterized. Finite element analysis has been used to model the device performance. It was found that one configuration of microtweezer, based on two lateral bimorph thermal actuators, has a small displacement (tip opening of the tweezers) and a very limited operating power range. An alternative configuration consisting of two horizontal hot bars with separated beams as the arms can deliver a larger displacement with a much-extended operating power range. This structure can withstand a higher temperature due to the wider beams used, and has flexible arms for increased displacement. Microtweezers driven by a number of chevron structures in parallel have similar maximum displacements but at a cost of higher power consumption. The measured temperature of the devices confirms that the device with the chevron structure can deliver the largest displacement for a given working temperature, while the bimorph thermal actuator design has the highest operating temperature at the same power due to its thin hot arm, and is prone to structural failure.

  19. Reconfigurable Secure Video Codec Based on DWT and AES Processor

    OpenAIRE

    Rached Tourki; M. Machhout; B. Bouallegue; M. Atri; M. Zeghid; D. Dia

    2010-01-01

    In this paper, we proposed a secure video codec based on the discrete wavelet transformation (DWT) and the Advanced Encryption Standard (AES) processor. Either, use of video coding with DWT or encryption using AES is well known. However, linking these two designs to achieve secure video coding is leading. The contributions of our work are as follows. First, a new method for image and video compression is proposed. This codec is a synthesis of JPEG and JPEG2000,which is implemented using Huffm...

  20. Multilayer modal actuator-based piezoelectric transformers.

    Science.gov (United States)

    Huang, Yao-Tien; Wu, Wen-Jong; Wang, Yen-Chieh; Lee, Chih-Kung

    2007-02-01

    An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well.

  1. Shape memory-based actuators and release mechanisms therefrom

    Science.gov (United States)

    Vaidyanathan, Rajan (Inventor); Snyder, Daniel W. (Inventor); Schoenwald, David K. (Inventor); Lam, Nhin S. (Inventor); Watson, Daniel S. (Inventor); Krishnan, Vinu B. (Inventor); Noebe, Ronald D. (Inventor)

    2012-01-01

    SM-based actuators (110) and release mechanisms (100) therefrom and systems (500) including one or more release mechanisms (100). The actuators (110) comprise a SM member (118) and a deformable member (140) mechanically coupled to the SM member (118) which deforms upon a shape change of the SM member triggered by a phase transition of the SM member. A retaining element (160) is mechanically coupled to the deformable member (140), wherein the retaining element (160) moves upon the shape change. Release mechanism (100) include an actuator, a rotatable mechanism (120) including at least one restraining feature (178) for restraining rotational movement of the retaining element (160) before the shape change, and at least one spring (315) that provides at least one locked spring-loaded position when the retaining element is in the restraining feature and at least one released position that is reached when the retaining element is in a position beyond the restraining feature (178). The rotatable mechanism (120) includes at least one load-bearing protrusion (310). A hitch (400) is for mechanically coupling to the load, wherein the hitch is supported on the load bearing protrusion (310) when the rotatable mechanism is in the locked spring-loaded position.

  2. Design and Simulation of an Electrothermal Actuator Based Rotational Drive

    Science.gov (United States)

    Beeson, Sterling; Dallas, Tim

    2008-10-01

    As a participant in the Micro and Nano Device Engineering (MANDE) Research Experience for Undergraduates program at Texas Tech University, I learned how MEMS devices operate and the limits of their operation. Using specialized AutoCAD-based design software and the ANSYS simulation program, I learned the MEMS fabrication process used at Sandia National Labs, the design limitations of this process, the abilities and drawbacks of micro devices, and finally, I redesigned a MEMS device called the Chevron Torsional Ratcheting Actuator (CTRA). Motion is achieved through electrothermal actuation. The chevron (bent-beam) actuators cause a ratcheting motion on top of a hub-less gear so that as voltage is applied the CTRA spins. The voltage applied needs to be pulsed and the frequency of the pulses determine the angular frequency of the device. The main objective was to design electromechanical structures capable of transforming the electrical signals into mechanical motion without overheating. The design was optimized using finite element analysis in ANSYS allowing multi-physics simulations of our model system.

  3. Reconfigurable Secure Video Codec Based on DWT and AES Processor

    Directory of Open Access Journals (Sweden)

    Rached Tourki

    2010-01-01

    Full Text Available In this paper, we proposed a secure video codec based on the discrete wavelet transformation (DWT and the Advanced Encryption Standard (AES processor. Either, use of video coding with DWT or encryption using AES is well known. However, linking these two designs to achieve secure video coding is leading. The contributions of our work are as follows. First, a new method for image and video compression is proposed. This codec is a synthesis of JPEG and JPEG2000,which is implemented using Huffman coding to the JPEG and DWT to the JPEG2000. Furthermore, an improved motion estimation algorithm is proposed. Second, the encryptiondecryption effects are achieved by the AES processor. AES is aim to encrypt group of LL bands. The prominent feature of this method is an encryption of LL bands by AES-128 (128-bit keys, or AES-192 (192-bit keys, or AES-256 (256-bit keys.Third, we focus on a method that implements partial encryption of LL bands. Our approach provides considerable levels of security (key size, partial encryption, mode encryption, and has very limited adverse impact on the compression efficiency. The proposed codec can provide up to 9 cipher schemes within a reasonable software cost. Latency, correlation, PSNR and compression rate results are analyzed and shown.

  4. Reconfiguration Management in the Context of RTOS-Based HW/SW Embedded Systems

    Directory of Open Access Journals (Sweden)

    Eustache Yvan

    2008-01-01

    Full Text Available Abstract This paper presents a safe and efficient solution to manage asynchronous configurations of dynamically reconfigurable systems-on-chip. We first define our unified RTOS-based framework for HW/SW task communication and configuration management. Then three issues are discussed and solutions are given: the formalization of configuration space modeling including its different dimensions, the synchronization of configuration that mainly addresses the question of task configuration ordering, and the configuration coherency that solves the way a task accepts a new configuration. Finally, we present the global method and give some implementation figures from a smart camera case study.

  5. Reconfiguration Management in the Context of RTOS-Based HW/SW Embedded Systems

    Directory of Open Access Journals (Sweden)

    Yvan Eustache

    2008-01-01

    Full Text Available This paper presents a safe and efficient solution to manage asynchronous configurations of dynamically reconfigurable systems-on-chip. We first define our unified RTOS-based framework for HW/SW task communication and configuration management. Then three issues are discussed and solutions are given: the formalization of configuration space modeling including its different dimensions, the synchronization of configuration that mainly addresses the question of task configuration ordering, and the configuration coherency that solves the way a task accepts a new configuration. Finally, we present the global method and give some implementation figures from a smart camera case study.

  6. SEU mitigation technique by Dynamic Reconfiguration method in FPGA based DSP application

    International Nuclear Information System (INIS)

    Dey, Madhusudan; Singh, Abhishek; Roy, Amitava

    2012-01-01

    Field Programmable Gate Array (FPGA), an SRAM based configurable devices meant for implementation of any digital circuits is susceptible to malfunction in the harsh radiation environment. It causes the corruption of the configuration memory of FPGA and the digital circuits starts malfunctioning. There is a need to restore the system as early as possible. This paper discusses about one such technique named dynamic partial reconfiguration (DPR) method. This paper also touches upon the signal processing by DPR method. The framework consisting of ADC, DAC and ICAP controllers designed using dedicated state machines to study the best possible downtime also for verifying the performance of digital filters for signal processing

  7. Rapidly reconfigurable slow-light system based on off-resonant Raman absorption

    International Nuclear Information System (INIS)

    Vudyasetu, Praveen K.; Howell, John C.; Camacho, Ryan M.

    2010-01-01

    We present a slow-light system based on dual Raman absorption resonances in warm rubidium vapor. Each Raman absorption resonance is produced by a control beam in an off-resonant Λ system. This system combines all optical control of the Raman absorption and the low-dispersion broadening properties of the double Lorentzian absorption slow light. The bandwidth, group delay, and central frequency of the slow-light system can all be tuned dynamically by changing the properties of the control beam. We demonstrate multiple pulse delays with low distortion and show that such a system has fast switching dynamics and thus fast reconfiguration rates.

  8. Soft silicone based interpenetrating networks as materials for actuators

    DEFF Research Database (Denmark)

    Yu, Liyun; Gonzalez, Lidia; Hvilsted, Søren

    2014-01-01

    A new approach based on silicone interpenetrating networks with orthogonal chemistries has been investigated with focus on developing soft and flexible elastomers with high energy densities and small viscous losses. The interpenetrating networks are made as simple two pot mixtures...... as for the commercial available silylation based elastomers such as Elastosil RT625. The resulting interpenetrating networks are formulated to be softer than RT625 to increase the actuation caused when applying a voltage due to their softness combined with the significantly higher permittivity than the pure silicone...

  9. Plasma actuators for active flow control based on a glow discharge

    International Nuclear Information System (INIS)

    Kühn, M.; Kühn-Kauffeldt, M.; Schein, J.; Belinger, A.

    2017-01-01

    In this work a glow discharge based active flow control for high flow velocities and low Reynolds numbers is presented. Unlike common plasma actuators such as dielectric barrier discharge (DBD) or spark jets, this actuator uses small impulse bits at frequencies. The actuator is optimized for frequencies up to 40 kHz to counter Tollmien Schlichting wave effects and so reduce overall air foil drag. Several measurements to prove the non-eroding effect of the actuator and the electrical properties were performed. It was found that the actuator is capable of operating at high frequencies without measurable erosion. (paper)

  10. Modelling of coulometric sensor-actuator systems based on ISFETs with a porous actuator covering the gate

    NARCIS (Netherlands)

    Luo, J.; Luo, J.; Olthuis, Wouter; Bergveld, Piet; Bos, M.; van der Linden, W.E.

    1993-01-01

    The ion-selective field effect transistor (ISFET)-based coulometric sensor¿actuator systems have found applications in acid¿base titration and in the construction of a low-drift carbon dioxide and a pH-static enzyme sensor. In this paper a brief review is given of the previously developed

  11. Design of a rotary dielectric elastomer actuator using a topology optimization method based on pairs of curves

    Science.gov (United States)

    Wang, Nianfeng; Guo, Hao; Chen, Bicheng; Cui, Chaoyu; Zhang, Xianmin

    2018-05-01

    Dielectric elastomers (DE), known as electromechanical transducers, have been widely used in the field of sensors, generators, actuators and energy harvesting for decades. A large number of DE actuators including bending actuators, linear actuators and rotational actuators have been designed utilizing an experience design method. This paper proposes a new method for the design of DE actuators by using a topology optimization method based on pairs of curves. First, theoretical modeling and optimization design are discussed, after which a rotary dielectric elastomer actuator has been designed using this optimization method. Finally, experiments and comparisons between several DE actuators have been made to verify the optimized result.

  12. A Reconfigurable Readout Integrated Circuit for Heterogeneous Display-Based Multi-Sensor Systems

    Directory of Open Access Journals (Sweden)

    Kyeonghwan Park

    2017-04-01

    Full Text Available This paper presents a reconfigurable multi-sensor interface and its readout integrated circuit (ROIC for display-based multi-sensor systems, which builds up multi-sensor functions by utilizing touch screen panels. In addition to inherent touch detection, physiological and environmental sensor interfaces are incorporated. The reconfigurable feature is effectively implemented by proposing two basis readout topologies of amplifier-based and oscillator-based circuits. For noise-immune design against various noises from inherent human-touch operations, an alternate-sampling error-correction scheme is proposed and integrated inside the ROIC, achieving a 12-bit resolution of successive approximation register (SAR of analog-to-digital conversion without additional calibrations. A ROIC prototype that includes the whole proposed functions and data converters was fabricated in a 0.18 μm complementary metal oxide semiconductor (CMOS process, and its feasibility was experimentally verified to support multiple heterogeneous sensing functions of touch, electrocardiogram, body impedance, and environmental sensors.

  13. Reconfiguring Worlds with Simple Actuation via Physics-Based Nonprehensile Actions

    Data.gov (United States)

    National Aeronautics and Space Administration — Increased capability in autonomous navigation has revolutionized space exploration. Autonomous rovers have allowed us to explore further and for longer durations...

  14. An Unconventional Inchworm Actuator Based on PZT/ERFs Control Technology.

    Science.gov (United States)

    Liu, Guojun; Zhang, Yanyan; Liu, Jianfang; Li, Jianqiao; Tang, Chunxiu; Wang, Tengfei; Yang, Xuhao

    2016-01-01

    An unconventional inchworm actuator for precision positioning based on piezoelectric (PZT) actuation and electrorheological fluids (ERFs) control technology is presented. The actuator consists of actuation unit (PZT stack pump), fluid control unit (ERFs valve), and execution unit (hydraulic actuator). In view of smaller deformation of PZT stack, a new structure is designed for actuation unit, which integrates the advantages of two modes (namely, diaphragm type and piston type) of the volume changing of pump chamber. In order to improve the static shear yield strength of ERFs, a composite ERFs valve is designed, which adopts the series-parallel plate compound structure. The prototype of the inchworm actuator has been designed and manufactured in the lab. Systematic test results indicate that the displacement resolution of the unconventional inchworm actuator reaches 0.038 μm, and the maximum driving force and velocity are 42 N, 14.8 mm/s, respectively. The optimal working frequency for the maximum driving velocity is 120 Hz. The complete research and development processes further confirm the feasibility of developing a new type of inchworm actuator with high performance based on PZT actuation and ERFs control technology, which provides a reference for the future development of a new type of actuator.

  15. An Unconventional Inchworm Actuator Based on PZT/ERFs Control Technology

    Directory of Open Access Journals (Sweden)

    Guojun Liu

    2016-01-01

    Full Text Available An unconventional inchworm actuator for precision positioning based on piezoelectric (PZT actuation and electrorheological fluids (ERFs control technology is presented. The actuator consists of actuation unit (PZT stack pump, fluid control unit (ERFs valve, and execution unit (hydraulic actuator. In view of smaller deformation of PZT stack, a new structure is designed for actuation unit, which integrates the advantages of two modes (namely, diaphragm type and piston type of the volume changing of pump chamber. In order to improve the static shear yield strength of ERFs, a composite ERFs valve is designed, which adopts the series-parallel plate compound structure. The prototype of the inchworm actuator has been designed and manufactured in the lab. Systematic test results indicate that the displacement resolution of the unconventional inchworm actuator reaches 0.038 μm, and the maximum driving force and velocity are 42 N, 14.8 mm/s, respectively. The optimal working frequency for the maximum driving velocity is 120 Hz. The complete research and development processes further confirm the feasibility of developing a new type of inchworm actuator with high performance based on PZT actuation and ERFs control technology, which provides a reference for the future development of a new type of actuator.

  16. New Incremental Actuators based on Electro-active Polymer: Conceptual, Control, and Driver Design Considerations. 

    OpenAIRE

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe; Andersen, Michael A. E.; Sarban, Rahimullah

    2016-01-01

    This paper presents an overview of the widely usedconventional linear actuator technologies and existing electroactivepolymer based linear and rotary actuators. It also providesthe conceptual, control and driver design considerations for anew dielectric electro-active polymer (DEAP) based incrementalactuator. The DEAP incremental actuator consists of threeindependent DEAP actuators with a unique cylindrical designthat potentially simplifies mass production and scalabilitycompared to existing ...

  17. SVM-Based Dynamic Reconfiguration CPS for Manufacturing System in Industry 4.0

    Directory of Open Access Journals (Sweden)

    Hyun-Jun Shin

    2018-01-01

    Full Text Available CPS is potential application in various fields, such as medical, healthcare, energy, transportation, and defense, as well as Industry 4.0 in Germany. Although studies on the equipment aging and prediction of problem have been done by combining CPS with Industry 4.0, such studies were based on small numbers and majority of the papers focused primarily on CPS methodology. Therefore, it is necessary to study active self-protection to enable self-management functions, such as self-healing by applying CPS in shop-floor. In this paper, we have proposed modeling of shop-floor and a dynamic reconfigurable CPS scheme that can predict the occurrence of anomalies and self-protection in the model. For this purpose, SVM was used as a machine learning technology and it was possible to restrain overloading in manufacturing process. In addition, we design CPS framework based on machine learning for Industry 4.0, simulate it, and perform. Simulation results show the simulation model autonomously detects the abnormal situation and it is dynamically reconfigured through self-healing.

  18. Using Partial Reconfiguration and Message Passing to Enable FPGA-Based Generic Computing Platforms

    Directory of Open Access Journals (Sweden)

    Manuel Saldaña

    2012-01-01

    Full Text Available Partial reconfiguration (PR is an FPGA feature that allows the modification of certain parts of an FPGA while the rest of the system continues to operate without disruption. This distinctive characteristic of FPGAs has many potential benefits but also challenges. The lack of good CAD tools and the deep hardware knowledge requirement result in a hard-to-use feature. In this paper, the new partition-based Xilinx PR flow is used to incorporate PR within our MPI-based message-passing framework to allow hardware designers to create template bitstreams, which are predesigned, prerouted, generic bitstreams that can be reused for multiple applications. As an example of the generality of this approach, four different applications that use the same template bitstream are run consecutively, with a PR operation performed at the beginning of each application to instantiate the desired application engine. We demonstrate a simplified, reusable, high-level, and portable PR interface for X86-FPGA hybrid machines. PR issues such as local resets of reconfigurable modules and context saving and restoring are addressed in this paper followed by some examples and preliminary PR overhead measurements.

  19. Enabling Fast ASIP Design Space Exploration: An FPGA-Based Runtime Reconfigurable Prototyper

    Directory of Open Access Journals (Sweden)

    Paolo Meloni

    2012-01-01

    Full Text Available Application Specific Instruction-set Processors (ASIPs expose to the designer a large number of degrees of freedom. Accurate and rapid simulation tools are needed to explore the design space. To this aim, FPGA-based emulators have recently been proposed as an alternative to pure software cycle-accurate simulator. However, the advantages of on-hardware emulation are reduced by the overhead of the RTL synthesis process that needs to be run for each configuration to be emulated. The work presented in this paper aims at mitigating this overhead, exploiting a form of software-driven platform runtime reconfiguration. We present a complete emulation toolchain that, given a set of candidate ASIP configurations, identifies and builds an overdimensioned architecture capable of being reconfigured via software at runtime, emulating all the design space points under evaluation. The approach has been validated against two different case studies, a filtering kernel and an M-JPEG encoding kernel. Moreover, the presented emulation toolchain couples FPGA emulation with activity-based physical modeling to extract area and power/energy consumption figures. We show how the adoption of the presented toolchain reduces significantly the design space exploration time, while introducing an overhead lower than 10% for the FPGA resources and lower than 0.5% in terms of operating frequency.

  20. Actuation mechanisms of carbon nanotube-based architectures

    Science.gov (United States)

    Geier, Sebastian; Mahrholz, Thorsten; Wierach, Peter; Sinapius, Michael

    2016-04-01

    State of the art smart materials such as piezo ceramics or electroactive polymers cannot feature both, mechanical stiffness and high active strain. Moreover, properties like low density, high mechanical stiffness and high strain at the same time driven by low energy play an increasingly important role for their future application. Carbon nanotubes (CNT), show this behavior. Their active behavior was observed 1999 the first time using paper-like mats made of CNT. Therefore the CNT-papers are electrical charged within an electrolyte thus forming a double- layer. The measured deflection of CNT material is based on the interaction between the charged high surface area formed by carbon nanotubes and ions provided by the electrolyte. Although CNT-papers have been extensively analyzed as well at the macro-scale as nano-scale there is still no generally accepted theory for the actuation mechanism. This paper focuses on investigations of the actuation mechanisms of CNT-papers in comparison to vertically aligned CNT-arrays. One reason of divergent results found in literature might be attributed to different types of CNT samples. While CNT-papers represent architectures of short CNTs which need to bridge each other to form the dimensions of the sample, the continuous CNTs of the array feature a length of almost 3 mm, along which the experiments are carried out. Both sample types are tested within an actuated tensile test set-up under different conditions. While the CNT-papers are tested in water-based electrolytes with comparably small redox-windows the hydrophobic CNT-arrays are tested in ionic liquids with comparatively larger redox-ranges. Furthermore an in-situ micro tensile test within an SEM is carried out to prove the optimized orientation of the MWCNTs as result of external load. It was found that the performance of CNT-papers strongly depends on the test conditions. However, the CNT-arrays are almost unaffected by the conditions showing active response at negative

  1. Fault Diagnosis of a Reconfigurable Crawling–Rolling Robot Based on Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Karthikeyan Elangovan

    2017-10-01

    Full Text Available As robots begin to perform jobs autonomously, with minimal or no human intervention, a new challenge arises: robots also need to autonomously detect errors and recover from faults. In this paper, we present a Support Vector Machine (SVM-based fault diagnosis system for a bio-inspired reconfigurable robot named Scorpio. The diagnosis system needs to detect and classify faults while Scorpio uses its crawling and rolling locomotion modes. Specifically, we classify between faulty and non-faulty conditions by analyzing onboard Inertial Measurement Unit (IMU sensor data. The data capture nine different locomotion gaits, which include rolling and crawling modes, at three different speeds. Statistical methods are applied to extract features and to reduce the dimensionality of original IMU sensor data features. These statistical features were given as inputs for training and testing. Additionally, the c-Support Vector Classification (c-SVC and nu-SVC models of SVM, and their fault classification accuracies, were compared. The results show that the proposed SVM approach can be used to autonomously diagnose locomotion gait faults while the reconfigurable robot is in operation.

  2. Tunable and reconfigurable multi-tap microwave photonic filter based on dynamic Brillouin gratings in fibers.

    Science.gov (United States)

    Sancho, J; Primerov, N; Chin, S; Antman, Y; Zadok, A; Sales, S; Thévenaz, L

    2012-03-12

    We propose and experimentally demonstrate new architectures to realize multi-tap microwave photonic filters, based on the generation of a single or multiple dynamic Brillouin gratings in polarization maintaining fibers. The spectral range and selectivity of the proposed periodic filters is extensively tunable, simply by reconfiguring the positions and the number of dynamic gratings along the fiber respectively. In this paper, we present a complete analysis of three different configurations comprising a microwave photonic filter implementation: a simple notch-type Mach-Zehnder approach with a single movable dynamic grating, a multi-tap performance based on multiple dynamic gratings and finally a stationary grating configuration based on the phase modulation of two counter-propagating optical waves by a common pseudo-random bit sequence (PRBS).

  3. A Novel Reconfigurable Logic Unit Based on the DNA-Templated Potassium-Concentration-Dependent Supramolecular Assembly.

    Science.gov (United States)

    Yang, Chunrong; Zou, Dan; Chen, Jianchi; Zhang, Linyan; Miao, Jiarong; Huang, Dan; Du, Yuanyuan; Yang, Shu; Yang, Qianfan; Tang, Yalin

    2018-03-15

    Plenty of molecular circuits with specific functions have been developed; however, logic units with reconfigurability, which could simplify the circuits and speed up the information process, are rarely reported. In this work, we designed a novel reconfigurable logic unit based on a DNA-templated, potassium-concentration-dependent, supramolecular assembly, which could respond to the input stimuli of H + and K + . By inputting different concentrations of K + , the logic unit could implement three significant functions, including a half adder, a half subtractor, and a 2-to-4 decoder. Considering its reconfigurable ability and good performance, the novel prototypes developed here may serve as a promising proof of principle in molecular computers. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. On-line Multiple-model Based Adaptive Control Reconfiguration for a Class of Non-linear Control Systems

    DEFF Research Database (Denmark)

    Yang, Z.; Izadi-Zamanabadi, R.; Blanke, Mogens

    2000-01-01

    of LTI models are employed to approximate the faulty, reconfigured and nominal nonlinear systems respectively with respect to the on-line information of the operating system, and a set of compensating modules are proposed and designed so as to make the local LTI model approximating to the reconfigured...... nonlinear system match the corresponding LTI model approximating to the nominal nonlinear system in some optimal sense. The compensating modules are designed by the Pseudo-Inverse Method based on the local LTI models for the nominal and faulty nonlinear systems. Moreover, these modules should update...... corresponding to the updating of local LTI models, which validations are determined by the model approximation errors and the optimal index of local design. The test on a nonlinear ship propulsion system shows the promising potential of this method for system reconfiguration...

  5. Paper-based Pneumatic Locomotive Robot with Sticky Actuator

    Directory of Open Access Journals (Sweden)

    Du Xiaohan

    2016-01-01

    Full Text Available Demands for small-scale and low-cost robots have witnessed a great increase in recent years [1–5]. This paper introduces the design and fabrication of a novel, simple, low-cost and designer-friendly locomotive robot. The materials and tools to build the robot originate from everyday life. The robot is pneumatically powered and manually controlled by simply pumping and vacuuming the syringe repeatedly, which realizes reliable locomotion by folding and opening of the planes. In order to realize this complicated motion, a “3D Sticky Actuator” is developed. The motion and force analysis of actuator are then modelled by the numerical method to develop the relations between design parameters. This suggests a systematic and user interactive way of manufacturing various shapes of the actuator, depending on user-defined road condition (e.g. obstacles and slopes and other constraints. One key advantage of the paper-based robot is suggested by its high feasibility.

  6. Asymmetric actuating structure generates negligible influence on the supporting base for high performance scanning probe microscopies

    Science.gov (United States)

    Yi Yan, Gang; Bin Liu, Yong; Hua Feng, Zhi

    2014-02-01

    An asymmetric actuating structure generating negligible influence on the supporting base for high performance scanning probe microscopies is proposed in this paper. The actuator structure consists of two piezostacks, one is used for actuating while the other is for counterbalancing. In contrast with balanced structure, the two piezostacks are installed at the same side of the supporting base. The effectiveness of the structure is proved by some experiments with the actuators fixed to the free end of a cantilever. Experimental results show that almost all of the vibration modes of the cantilever are suppressed effectively at a wide frequency range of 90 Hz-10 kHz.

  7. Smart Material-Actuated Flexible Tendon-Based Snake Robot

    Directory of Open Access Journals (Sweden)

    Mohiuddin Ahmed

    2016-05-01

    Full Text Available A flexible snake robot has better navigation ability compare with the existing electrical motor-based rigid snake robot, due to its excellent bending capability during navigation inside a narrow maze. This paper discusses the modelling, simulation and experiment of a flexible snake robot. The modelling consists of the kinematic analysis and the dynamic analysis of the snake robot. A platform based on the Incompletely Restrained Positioning Mechanism (IRPM is proposed, which uses the external force provided by a compliant flexible beam in each of the actuators. The compliant central column allows the configuration to achieve three degrees of freedom (3DOFs with three tendons. The proposed flexible snake robot has been built using smart material, such as electroactive polymers (EAPs, which can be activated by applying power to it. Finally, the physical prototype of the snake robot has been built. An experiment has been performed in order to justify the proposed model.

  8. Graphitic carbon nitride nanosheet electrode-based high-performance ionic actuator

    Science.gov (United States)

    Wu, Guan; Hu, Ying; Liu, Yang; Zhao, Jingjing; Chen, Xueli; Whoehling, Vincent; Plesse, Cédric; Nguyen, Giao T. M.; Vidal, Frédéric; Chen, Wei

    2015-01-01

    Ionic actuators have attracted attention due to their remarkably large strain under low-voltage stimulation. Because actuation performance is mainly dominated by the electrochemical and electromechanical processes of the electrode layer, the electrode material and structure are crucial. Here, we report a graphitic carbon nitride nanosheet electrode-based ionic actuator that displays high electrochemical activity and electromechanical conversion abilities, including large specific capacitance (259.4 F g−1) with ionic liquid as the electrolyte, fast actuation response (0.5±0.03% in 300 ms), large electromechanical strain (0.93±0.03%) and high actuation stability (100,000 cycles) under 3 V. The key to the high performance lies in the hierarchical pore structure with dominant size actuation performance. PMID:26028354

  9. Bismuth Sodium Titanate Based Materials for Piezoelectric Actuators.

    Science.gov (United States)

    Reichmann, Klaus; Feteira, Antonio; Li, Ming

    2015-12-04

    The ban of lead in many electronic products and the expectation that, sooner or later, this ban will include the currently exempt piezoelectric ceramics based on Lead-Zirconate-Titanate has motivated many research groups to look for lead-free substitutes. After a short overview on different classes of lead-free piezoelectric ceramics with large strain, this review will focus on Bismuth-Sodium-Titanate and its solid solutions. These compounds exhibit extraordinarily high strain, due to a field induced phase transition, which makes them attractive for actuator applications. The structural features of these materials and the origin of the field-induced strain will be revised. Technologies for texturing, which increases the useable strain, will be introduced. Finally, the features that are relevant for the application of these materials in a multilayer design will be summarized.

  10. Rotational actuator of motor based on carbon nanotubes

    Science.gov (United States)

    Zettl, Alexander K.; Fennimore, Adam M.; Yuzvinsky, Thomas D.

    2008-11-18

    A rotational actuator/motor based on rotation of a carbon nanotube is disclosed. The carbon nanotube is provided with a rotor plate attached to an outer wall, which moves relative to an inner wall of the nanotube. After deposit of a nanotube on a silicon chip substrate, the entire structure may be fabricated by lithography using selected techniques adapted from silicon manufacturing technology. The structures to be fabricated may comprise a multiwall carbon nanotube (MWNT), two in plane stators S1, S2 and a gate stator S3 buried beneath the substrate surface. The MWNT is suspended between two anchor pads and comprises a rotator attached to an outer wall and arranged to move in response to electromagnetic inputs. The substrate is etched away to allow the rotor to freely rotate. Rotation may be either in a reciprocal or fully rotatable manner.

  11. Optimized electrode coverage of membrane actuators based on epitaxial PZT thin films

    International Nuclear Information System (INIS)

    Nguyen, M D; Dekkers, M; Blank, D H A; Rijnders, G; Nazeer, H

    2013-01-01

    This research presents an optimization of piezoelectric membrane actuators by maximizing the actuator displacement. Membrane actuators based on epitaxial Pb(Zr,Ti)O 3 thin films grown on all-oxide electrodes and buffer layers using silicon technology were fabricated. Electrode coverage was found to be an important factor in the actuation displacement of the piezoelectric membranes. The optimum electrode coverage for maximum displacement was theoretically determined to be 39%, which is in good agreement with the experimental results. Dependences of membrane displacement and optimum electrode coverage on membrane diameter and PZT-film/Si-device-layer thickness ratio have also been investigated. (paper)

  12. Actuators based on polyurethanes with different types of polyol

    Science.gov (United States)

    Lim, Hyun-Ok; Bark, Geong-Mi; Jo, Nam-Ju

    2007-07-01

    This study dealt with the electrostrictive responses of polyurethane (PU) actuators with different microphase separation structure, which was a promising candidate for a material used in polymer actuators. In order to construct PUs with different higher-order structure, we synthesized PUs with different diols; poly(neopentyl glycol adipate) (PNAD), poly(tetramethylene glycol) (PTMG), and poly(dimethyl siloxnae) (PDMS). Synthesized PU was characterized by FT-IR spectroscopy and GPC. Thermal analysis and mechanical properties of PU films were carried out with DSC and UTM, respectively. And PU actuator was formed in a monomorph type which made by carbon black electrodes on the both surfaces of PU film by spin coating method. Actuation behavior was mainly influenced on microphase separation structure and mechanical property of PU. In result, PU actuator with PNAD, polyester urethane, had the largest field-induced displacement.

  13. Polymer-based actuators for virtual reality devices

    Science.gov (United States)

    Bolzmacher, Christian; Hafez, Moustapha; Benali Khoudja, Mohamed; Bernardoni, Paul; Dubowsky, Steven

    2004-07-01

    Virtual Reality (VR) is gaining more importance in our society. For many years, VR has been limited to the entertainment applications. Today, practical applications such as training and prototyping find a promising future in VR. Therefore there is an increasing demand for low-cost, lightweight haptic devices in virtual reality (VR) environment. Electroactive polymers seem to be a potential actuation technology that could satisfy these requirements. Dielectric polymers developed the past few years have shown large displacements (more than 300%). This feature makes them quite interesting for integration in haptic devices due to their muscle-like behaviour. Polymer actuators are flexible and lightweight as compared to traditional actuators. Using stacks with several layers of elatomeric film increase the force without limiting the output displacement. The paper discusses some design methods for a linear dielectric polymer actuator for VR devices. Experimental results of the actuator performance is presented.

  14. MEMS fluidic actuator

    Science.gov (United States)

    Kholwadwala, Deepesh K [Albuquerque, NM; Johnston, Gabriel A [Trophy Club, TX; Rohrer, Brandon R [Albuquerque, NM; Galambos, Paul C [Albuquerque, NM; Okandan, Murat [Albuquerque, NM

    2007-07-24

    The present invention comprises a novel, lightweight, massively parallel device comprising microelectromechanical (MEMS) fluidic actuators, to reconfigure the profile, of a surface. Each microfluidic actuator comprises an independent bladder that can act as both a sensor and an actuator. A MEMS sensor, and a MEMS valve within each microfluidic actuator, operate cooperatively to monitor the fluid within each bladder, and regulate the flow of the fluid entering and exiting each bladder. When adjacently spaced in a array, microfluidic actuators can create arbitrary surface profiles in response to a change in the operating environment of the surface. In an embodiment of the invention, the profile of an airfoil is controlled by independent extension and contraction of a plurality of actuators, that operate to displace a compliant cover.

  15. FPGA-based reconfigurable processor for ultrafast interlaced ultrasound and photoacoustic imaging.

    Science.gov (United States)

    Alqasemi, Umar; Li, Hai; Aguirre, Andrés; Zhu, Quing

    2012-07-01

    In this paper, we report, to the best of our knowledge, a unique field-programmable gate array (FPGA)-based reconfigurable processor for real-time interlaced co-registered ultrasound and photoacoustic imaging and its application in imaging tumor dynamic response. The FPGA is used to control, acquire, store, delay-and-sum, and transfer the data for real-time co-registered imaging. The FPGA controls the ultrasound transmission and ultrasound and photoacoustic data acquisition process of a customized 16-channel module that contains all of the necessary analog and digital circuits. The 16-channel module is one of multiple modules plugged into a motherboard; their beamformed outputs are made available for a digital signal processor (DSP) to access using an external memory interface (EMIF). The FPGA performs a key role through ultrafast reconfiguration and adaptation of its structure to allow real-time switching between the two imaging modes, including transmission control, laser synchronization, internal memory structure, beamforming, and EMIF structure and memory size. It performs another role by parallel accessing of internal memories and multi-thread processing to reduce the transfer of data and the processing load on the DSP. Furthermore, because the laser will be pulsing even during ultrasound pulse-echo acquisition, the FPGA ensures that the laser pulses are far enough from the pulse-echo acquisitions by appropriate time-division multiplexing (TDM). A co-registered ultrasound and photoacoustic imaging system consisting of four FPGA modules (64-channels) is constructed, and its performance is demonstrated using phantom targets and in vivo mouse tumor models.

  16. New Incremental Actuators based on Electro-active Polymer: Conceptual, Control, and Driver Design Considerations

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Schneider, Henrik; Zhang, Zhe

    2016-01-01

    This paper presents an overview of the widely usedconventional linear actuator technologies and existing electroactivepolymer based linear and rotary actuators. It also providesthe conceptual, control and driver design considerations for anew dielectric electro-active polymer (DEAP) based...

  17. Reconfigurable computing the theory and practice of FPGA-based computation

    CERN Document Server

    Hauck, Scott

    2010-01-01

    Reconfigurable Computing marks a revolutionary and hot topic that bridges the gap between the separate worlds of hardware and software design- the key feature of reconfigurable computing is its groundbreaking ability to perform computations in hardware to increase performance while retaining the flexibility of a software solution. Reconfigurable computers serve as affordable, fast, and accurate tools for developing designs ranging from single chip architectures to multi-chip and embedded systems. Scott Hauck and Andre DeHon have assembled a group of the key experts in the fields of both hardwa

  18. Low voltage driven dielectric electro active polymer actuator with integrated piezoelectric transformer based driver

    DEFF Research Database (Denmark)

    Andersen, Thomas; Rødgaard, Martin Schøler; Thomsen, Ole Cornelius

    2011-01-01

    actuators, a low voltage solution is developed by integrating the driver electronic into a 110 mm tall cylindrical coreless Push InLastor actuator. To decrease the size of the driver, a piezoelectric transformer (PT) based solution is utilized. The PT is essentially an improved Rosen type PT...

  19. Reconfigurable Computing

    CERN Document Server

    Cardoso, Joao MP

    2011-01-01

    As the complexity of modern embedded systems increases, it becomes less practical to design monolithic processing platforms. As a result, reconfigurable computing is being adopted widely for more flexible design. Reconfigurable Computers offer the spatial parallelism and fine-grained customizability of application-specific circuits with the postfabrication programmability of software. To make the most of this unique combination of performance and flexibility, designers need to be aware of both hardware and software issues. FPGA users must think not only about the gates needed to perform a comp

  20. New methods to engineer and seamlessly reconfigure time triggered ethernet based systems during runtime based on the PROFINET IRT example

    CERN Document Server

    Wisniewski, Lukasz

    2017-01-01

    The objective of this dissertation is to design a concept that would allow to increase the flexibility of currently available Time Triggered Ethernet based (TTEB) systems, however, without affecting their performance and robustness. The main challenges are related to scheduling of time triggered communication that may take significant amount of time and has to be performed on a powerful platform. Additionally, the reliability has to be considered and kept on the required high level. Finally, the reconfiguration has to be optimally done without affecting the currently running system.

  1. Reconfiguration in FPGA-Based Multi-Core Platforms for Hard Real-Time Applications

    DEFF Research Database (Denmark)

    Pezzarossa, Luca; Schoeberl, Martin; Sparsø, Jens

    2016-01-01

    -case execution-time of tasks of an application that determines the systems ability to respond in time. To support this focus, the platform must provide service guarantees for both communication and computation resources. In addition, many hard real-time applications have multiple modes of operation, and each......In general-purpose computing multi-core platforms, hardware accelerators and reconfiguration are means to improve performance; i.e., the average-case execution time of a software application. In hard real-time systems, such average-case speed-up is not in itself relevant - it is the worst...... mode has specific requirements. An interesting perspective on reconfigurable computing is to exploit run-time reconfiguration to support mode changes. In this paper we explore approaches to reconfiguration of communication and computation resources in the T-CREST hard real-time multi-core platform...

  2. A Controller for Dynamic Partial Reconfiguration in FPGA-Based Real-Time Systems

    DEFF Research Database (Denmark)

    Pezzarossa, Luca; Schoeberl, Martin; Sparsø, Jens

    2017-01-01

    -source DPR controller specially developed for hard real-time systems and prototyped in connection with the open-source multi-core platform for real-time applications T-CREST. The controller enables a processor to perform reconfiguration in a time-predictable manner and supports different operating modes......In real-time systems, the use of hardware accelerators can lead to a worst-case execution-time speed-up, to a simplification of its analysis, and to a reduction of its pessimism. When using FPGA technology, dynamic partial reconfiguration (DPR) can be used to minimize the area, by only loading....... The paper also presents a software tool for bitstream conversion, compression, and for reconfiguration time analysis. The DPR controller is evaluated in terms of hardware cost, operating frequency, speed, and bitstream compression ratio vs. reconfiguration time trade-off. A simple application example...

  3. Virtual network topology reconfiguration based on big data analytics for traffic prediction

    OpenAIRE

    Morales Alcaide, Fernando; Ruiz Ramírez, Marc; Velasco Esteban, Luis Domingo

    2016-01-01

    Big data analytics is applied for IP traffic prediction. When the virtual topology needs to be reconfigured, predicted and current traffic matrices are used to find the optimal topology. Exhaustive simulation results reveal large benefits. Peer Reviewed

  4. Block RAM-based architecture for real-time reconfiguration using Xilinx® FPGAs

    Directory of Open Access Journals (Sweden)

    Rikus le Roux

    2015-07-01

    Full Text Available Despite the advantages dynamic reconfiguration adds to a system, it only improves system performance if the execution time exceeds the configuration time. As a result, dynamic reconfiguration is only capable of improving the performance of quasi-static applications. In order to improve the performance of dynamic applications, researchers focus on improving the reconfiguration throughput. These approaches are mostly limited by the bus commonly used to connect the configuration controller to the memory, which contributes to the configuration time. A method proposed to ameliorate this overhead is an architecture utilizing localised block RAM (BRAM connected to the configuration controller to store the configuration bitstream. The aim of this paper is to illustrate the advantages of the proposed architecture, especially for reconfiguring real-time applications. This is done by validating the throughput of the architecture and comparing this to the maximum theoretical throughput of the internal configuration access port (ICAP. It was found that the proposed architecture is capable of reconfiguring an application within a time-frame suitable for real-time reconfiguration. The drawback of this method is that the BRAM is extremely limited and only a discrete set of configurations can be stored. This paper also proposes a method on how this can be mitigated without affecting the throughput.

  5. An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

    Science.gov (United States)

    Park, Won-Hyeong; Shin, Eun-Jae; Yun, Sungryul; Kim, Sang-Youn

    2018-01-01

    In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

  6. Design and performance analysis of position-based impedance control for an electrohydrostatic actuation system

    Directory of Open Access Journals (Sweden)

    Yongling FU

    2018-03-01

    Full Text Available Electrohydrostatic actuator (EHA is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots. This paper presents the development and evaluation of position-based impedance control (PBIC for an EHA. Impedance control provides the actuator with compliance and facilitates the interaction with the environment. Most impedance control applications utilize electrical or valve-controlled hydraulic actuators, whereas this work realizes impedance control via a compact and efficient EHA. The structures of the EHA and PBIC are firstly introduced. A mathematical model of the actuation system is established, and values of its coefficients are identified by particle swarm optimization. This model facilitates the development of a position controller and the selection of target impedance parameters. A nonlinear proportional-integral position controller is developed for the EHA to achieve the accurate positioning requirement of PBIC. The controller compensates for the adverse effect of stiction, and a position accuracy of 0.08 mm is attained. Various experimental results are presented to verify the applicability of PBIC to the EHA. The compliance of the actuator is demonstrated in an impact test. Keywords: Actuation system, Aerospace, Electrohydrostatic actuator, Force control, Nonlinear dynamics, Particle swarm optimization, Position control

  7. Centralised versus Decentralised Control Reconfiguration for Collaborating Underwater Robots

    DEFF Research Database (Denmark)

    Furno, Lidia; Nielsen, Mikkel Cornelius; Blanke, Mogens

    2015-01-01

    The present paper introduces an approach to fault-tolerant reconfiguration for collaborating underwater robots. Fault-tolerant reconfiguration is obtained using the virtual actuator approach, Steen (2005). The paper investigates properties of a centralised versus a decentralised implementation an...... an underwater drill needs to be transported and positioned by three collaborating robots as part of an underwater autonomous operation....

  8. Transparent Runtime Migration of Loop-Based Traces of Processor Instructions to Reconfigurable Processing Units

    Directory of Open Access Journals (Sweden)

    João Bispo

    2013-01-01

    Full Text Available The ability to map instructions running in a microprocessor to a reconfigurable processing unit (RPU, acting as a coprocessor, enables the runtime acceleration of applications and ensures code and possibly performance portability. In this work, we focus on the mapping of loop-based instruction traces (called Megablocks to RPUs. The proposed approach considers offline partitioning and mapping stages without ignoring their future runtime applicability. We present a toolchain that automatically extracts specific trace-based loops, called Megablocks, from MicroBlaze instruction traces and generates an RPU for executing those loops. Our hardware infrastructure is able to move loop execution from the microprocessor to the RPU transparently, at runtime, and without changing the executable binaries. The toolchain and the system are fully operational. Three FPGA implementations of the system, differing in the hardware interfaces used, were tested and evaluated with a set of 15 application kernels. Speedups ranging from 1.26 to 3.69 were achieved for the best alternative using a MicroBlaze processor with local memory.

  9. Modeling and test of a kinaesthetic actuator based on MR fluid for haptic applications.

    Science.gov (United States)

    Yang, Tae-Heon; Koo, Jeong-Hoi; Kim, Sang-Youn; Kwon, Dong-Soo

    2017-03-01

    Haptic display units have been widely used for conveying button sensations to users, primarily employing vibrotactile actuators. However, the human feeling for pressing buttons mainly relies on kinaesthetic sensations (rather than vibrotactile sensations), and little studies exist on small-scale kinaesthetic haptic units. Thus, the primary goals of this paper are to design a miniature kinaesthetic actuator based on Magneto-Rheological (MR) fluid that can convey various button-clicking sensations and to experimentally evaluate its haptic performance. The design focuses of the proposed actuator were to produce sufficiently large actuation forces (resistive forces) for human users in a given size constraint and to offer a wide range of actuation forces for conveying vivid haptic sensations to users. To this end, this study first performed a series of parametric studies using mathematical force models for multiple operating modes of MR fluid in conjunction with finite element electromagnetism analysis. After selecting design parameters based on parametric studies, a prototype actuator was constructed, and its performance was evaluated using a dynamic mechanical analyzer. It measured the actuator's resistive force with a varying stroke (pressed depth) up to 1 mm and a varying input current from 0 A to 200 mA. The results show that the proposed actuator creates a wide range of resistive forces from around 2 N (off-state) to over 9.5 N at 200 mA. In order to assess the prototype's performance in the terms of the haptic application prospective, a maximum force rate was calculated to determine just noticeable difference in force changes for the 1 mm stoke of the actuator. The results show that the force rate is sufficient to mimic various levels of button sensations, indicating that the proposed kinaesthetic actuator can offer a wide range of resistive force changes that can be conveyed to human operators.

  10. Actuated polymer based dielectric mirror for visual spectral range applications

    Science.gov (United States)

    Vergara, Pedro P.; Lunardi, Leda

    2017-08-01

    Miniature dielectric mirrors are useful components for lasers, thin film beam splitters and high quality mirrors in optics. These mirrors usually made from rigid inorganic materials can achieve a reflectance of almost one hundred percent. Being structural components, as soon as fabricated their reflectance and/or bandwidth remains constant. Here it is presented a novel fabrication process of a dielectric mirror based on free standing polymer layers. By applying an electrostatic force between the top and the bottom layers the reflectance can be changed. The large difference between the polymers refractive index and the air allows to achieve a reflectance of more than 85% using only six pairs of nanolayers. Preliminary simulations indicate an actuation speed of less than 1ms. Experimental optical characterization of fabricated structures agrees well with simulation results. Furthermore, structures can be designed to reflect a particular set of colors and/or isolated by using color filters, so a color pixel is fabricated, where the reflectance for each isolated color can be voltage controlled. Potential applications include an active component in a reflective screen display.

  11. A novel reconfigurable electromagnetically induced transparency based on S-PINs

    Science.gov (United States)

    Xue, Feng; Liu, Shao-Bin; Zhang, Hai-Feng; Wen, Yong-Diao; Kong, Xiang-Kun; Li, Hai-Ming

    2018-02-01

    In this paper, a tunable electromagnetically induced transparency (EIT) based on S-PINs is theoretically analyzed. Unit cell of the structure consists of a cutwire (CW), split ring resonator (SRR), and solid state plasma (SS plasma) patches which are composed of S-PIN array. The destructive interference between the CW and SRR results in a narrowband transparency window accompanied with strong phase dispersion. The proposed design can obtain a tunable EIT with different frequencies range from 12.8 GHz to 16.5 GHz in a simple method by switching these S-PINs on or off selectively. The related parameters of the S-PIN such as the size, carrier concentration, and volt-ampere characteristics have been studied theoretically. The interaction and coupling between two resonators are investigated in detail by the analysis of the current distribution and E-field strength as well. The research results provide an effective way to realize reconfigurable compact slow-light devices.

  12. Fabrication of a Miniature Paper-Based Electroosmotic Actuator

    Directory of Open Access Journals (Sweden)

    Deepa Sritharan

    2016-11-01

    Full Text Available A voltage-controlled hydraulic actuator is presented that employs electroosmotic fluid flow (EOF in paper microchannels within an elastomeric structure. The microfluidic device was fabricated using a new benchtop lamination process. Flexible embedded electrodes were formed from a conductive carbon-silicone composite. The pores in the layer of paper placed between the electrodes served as the microchannels for EOF, and the pumping fluid was propylene carbonate. A sealed fluid-filled chamber was formed by film-casting silicone to lay an actuating membrane over the pumping liquid. Hydraulic force generated by EOF caused the membrane to bulge by hundreds of micrometers within fractions of a second. Potential applications of these actuators include soft robots and biomedical devices.

  13. An artificial flexible robot arm based on pneumatic muscle actuators

    Directory of Open Access Journals (Sweden)

    Renn Jyh-Chyang

    2017-01-01

    Full Text Available The purpose of this paper is to develop a novel human-friendly artificial flexible robot arm using four parallel-connected pneumatic muscle actuators (PMAs. The PMA is a flexible silicone rubber actuator which has some behaviors nearest to the real biological muscle including translational and rotational motions. An inverse kinematic model for the motion control is also developed. Finally, from experiment results, it is proved that not only the axial contraction control of a single PMA but also the attitude control of the whole pneumatic flexible robot arm using PID controller are satisfactory.

  14. High-strain actuator materials based on dielectric elastomers

    DEFF Research Database (Denmark)

    Pelrine, R.; Kornbluh, R.; Kofod, G.

    2000-01-01

    Dielectric elastomers are a new class of actuator materials that exhibit excellent performance. The principle of operation, as well as methods to fabricate and test these elastomers, is summarized here. The Figure is a sketch of an elastomer film (light gray) stretched on a frame (black) and patt......Dielectric elastomers are a new class of actuator materials that exhibit excellent performance. The principle of operation, as well as methods to fabricate and test these elastomers, is summarized here. The Figure is a sketch of an elastomer film (light gray) stretched on a frame (black...

  15. a New ER Fluid Based Haptic Actuator System for Virtual Reality

    Science.gov (United States)

    Böse, H.; Baumann, M.; Monkman, G. J.; Egersdörfer, S.; Tunayar, A.; Freimuth, H.; Ermert, H.; Khaled, W.

    The concept and some steps in the development of a new actuator system which enables the haptic perception of mechanically inhomogeneous virtual objects are introduced. The system consists of a two-dimensional planar array of actuator elements containing an electrorheological (ER) fluid. When a user presses his fingers onto the surface of the actuator array, he perceives locally variable resistance forces generated by vertical pistons which slide in the ER fluid through the gaps between electrode pairs. The voltage in each actuator element can be individually controlled by a novel sophisticated switching technology based on optoelectric gallium arsenide elements. The haptic information which is represented at the actuator array can be transferred from a corresponding sensor system based on ultrasonic elastography. The combined sensor-actuator system may serve as a technology platform for various applications in virtual reality, like telemedicine where the information on the consistency of tissue of a real patient is detected by the sensor part and recorded by the actuator part at a remote location.

  16. A DP based scheme for real-time reconfiguration of solar cell arrays exposed to dynamic changing inhomogeneous illuminations

    DEFF Research Database (Denmark)

    Shi, Liping; Brehm, Robert

    2016-01-01

    The overall energy conversion efficiency of solar cell arrays is highly effected by partial shading effects. Especially for solar panel arrays installed in environments which are exposed to inhomogeneous dynamic changing illuminations such as on roof tops of electrical vehicles the overall system...... efficiency is drastically reduced. Dynamic real-time reconfiguration of the solar panel array can reduce effects on the output efficiency due to partial shading. This results in a maximized power output of the panel array when exposed to dynamic changing illuminations. The optimal array configuration...... with respect to shading patterns can be stated as a combinatorial optimization problem and this paper proposes a dynamic programming (DP) based algorithm which finds the optimal feasible solution to reconfigure the solar panel array for maximum efficiency in real-time with linear time complexity. It is shown...

  17. Towards Python-based Domain-specific Languages for Self-reconfigurable Modular Robotics Research

    DEFF Research Database (Denmark)

    Moghadam, Mikael; Johan Christensen, David; Brandt, David

    2013-01-01

    This paper explores the role of operating system and high-level languages in the development of software and domain-specific languages (DSLs) for self-reconfigurable robotics. We review some of the current trends in self-reconfigurable robotics and describe the development of a software system...... for ATRON II which utilizes Linux and Python to significantly improve software abstraction and portability while providing some basic features which could prove useful when using Python, either stand-alone or via a DSL, on a self-reconfigurable robot system. These features include transparent socket...... communication, module identification, easy software transfer and reliable module-to-module communication. The end result is a software platform for modular robots that where appropriate builds on existing work in operating systems, virtual machines, middleware and high-level languages....

  18. Modelling, Simulation and Testing of a Reconfigurable Cable-Based Parallel Manipulator as Motion Aiding System

    Directory of Open Access Journals (Sweden)

    Gianni Castelli

    2010-01-01

    Full Text Available This paper presents results on the modelling, simulation and experimental tests of a cable-based parallel manipulator to be used as an aiding or guiding system for people with motion disabilities. There is a high level of motivation for people with a motion disability or the elderly to perform basic daily-living activities independently. Therefore, it is of great interest to design and implement safe and reliable motion assisting and guiding devices that are able to help end-users. In general, a robot for a medical application should be able to interact with a patient in safety conditions, i.e. it must not damage people or surroundings; it must be designed to guarantee high accuracy and low acceleration during the operation. Furthermore, it should not be too bulky and it should exert limited wrenches after close interaction with people. It can be advisable to have a portable system which can be easily brought into and assembled in a hospital or a domestic environment. Cable-based robotic structures can fulfil those requirements because of their main characteristics that make them light and intrinsically safe. In this paper, a reconfigurable four-cable-based parallel manipulator has been proposed as a motion assisting and guiding device to help people to accomplish a number of tasks, such as an aiding or guiding system to move the upper and lower limbs or the whole body. Modelling and simulation are presented in the ADAMS environment. Moreover, experimental tests are reported as based on an available laboratory prototype.

  19. Design and characterization of low-cost fabric-based flat pneumatic actuators for soft assistive glove application.

    Science.gov (United States)

    Yap, Hong Kai; Sebastian, Frederick; Wiedeman, Christopher; Yeow, Chen-Hua

    2017-07-01

    We present the design of low-cost fabric-based Hat pneumatic actuators for soft assistive glove application. The soft assistive glove is designed to assist hand impaired patients in performing activities of daily living and rehabilitation. The actuators consist of flexible materials such as fabric and latex bladder. Using zero volume actuation concept, the 2D configuration of the actuators simplifies the manufacturing process and allows the actuators to be more compact. The actuators achieve bi-directional flexion and extension motions. Compared to previously developed inflatable soft actuators, the actuators generate sufficient force and torque to assist in both finger flexion and extension at lower air pressure. Preliminary evaluation results show that the glove is able to provide both active finger flexion and extension assistance for activities of daily living and rehabilitative training.

  20. Design and property analysis of a hybrid linear actuator based on shape memory alloy

    International Nuclear Information System (INIS)

    Zhang, Xiaoguang; Hu, Jinhong; Mao, Shixin; Dong, Erbao; Yang, Jie

    2014-01-01

    This paper introduces two methods for solving two bottlelike problems regarding the shape memory alloy (SMA) application as actuators. These methods are ‘rotating output,’ which aims to solve the problem of the low working frequency caused by the demand for cool time, and ‘accumulated shifting,’ which solves the problem of difficult-to-obtain output displacements in a large scale. We also introduce a hybrid linear actuator that applies the two methods and achieves both a strong force and an accurate large output displacement while working at a high frequency based on the SMA wires and DC motors. A prototype of this actuator was fabricated and tested to verify the two methods. This hybrid actuator system dynamic model, which was composed of the constitutive model of the SMA, the electrical and heat transfer behavior of the SMA wires and the dynamics of the linear actuation system, was established and discussed. Our study aims to illuminate the application of an SMA in actuators with the proposed methods with regard to its two main problems. An actuator with a high power-weight ratio and the capability to work at a high frequency, as well as accurate linear step displacements in a large scale, is also presented. (paper)

  1. LES-based characterization of a suction and oscillatory blowing fluidic actuator

    Science.gov (United States)

    Kim, Jeonglae; Moin, Parviz

    2015-11-01

    Recently, a novel fluidic actuator using steady suction and oscillatory blowing was developed for control of turbulent flows. The suction and oscillatory blowing (SaOB) actuator combines steady suction and pulsed oscillatory blowing into a single device. The actuation is based upon a self-sustained mechanism of confined jets and does not require any moving parts. The control output is determined by a pressure source and the geometric details, and no additional input is needed. While its basic mechanisms have been investigated to some extent, detailed characteristics of internal turbulent flows are not well understood. In this study, internal flows of the SaOB actuator are simulated using large-eddy simulation (LES). Flow characteristics within the actuator are described in detail for a better understanding of the physical mechanisms and improving the actuator design. LES predicts the self-sustained oscillations of the turbulent jet. Switching frequency, maximum velocity at the actuator outlets, and wall pressure distribution are in good agreement with the experimental measurements. The computational results are used to develop simplified boundary conditions for numerical experiments of active flow control. Supported by the Boeing company.

  2. Network topology exploration of mesh-based coarse-grain reconfigurable architectures

    NARCIS (Netherlands)

    Bansal, N.; Gupta, S.; Dutt, N.D.; Nicolau, A.; Gupta, R.

    2004-01-01

    Several coarse-grain reconfigurable architectures proposed recently consist of a large number of processing elements (PEs) connected in a mesh-like network topology. We study the effects of three aspects of network topology exploration on the performance of applications on these architectures: (a)

  3. Humidity Responsive Photonic Sensor based on a Carboxymethyl Cellulose Mechanical Actuator

    OpenAIRE

    Hartings, Matthew; Douglass, Kevin O.; Neice, Claire; Ahmed, Zeeshan

    2017-01-01

    We describe an intuitive and simple method for exploiting humidity-driven volume changes in carboxymethyl cellulose (CMC) to fabricate a humidity responsive actuator on a glass fiber substrate. We optimize this platform to generate a photonic-based humidity sensor where CMC coated on a fiber optic containing a fiber Bragg grating (FBG) actuates a mechanical strain in response to humidity changes. The humidity-driven mechanical deformation of the FBG results in a large lin...

  4. Multipoint dynamically reconfigure adaptive distributed fiber optic acoustic emission sensor (FAESense) system for condition based maintenance

    Science.gov (United States)

    Mendoza, Edgar; Prohaska, John; Kempen, Connie; Esterkin, Yan; Sun, Sunjian; Krishnaswamy, Sridhar

    2010-09-01

    This paper describes preliminary results obtained under a Navy SBIR contract by Redondo Optics Inc. (ROI), in collaboration with Northwestern University towards the development and demonstration of a next generation, stand-alone and fully integrated, dynamically reconfigurable, adaptive fiber optic acoustic emission sensor (FAESense™) system for the in-situ unattended detection and localization of shock events, impact damage, cracks, voids, and delaminations in new and aging critical infrastructures found in ships, submarines, aircraft, and in next generation weapon systems. ROI's FAESense™ system is based on the integration of proven state-of-the-art technologies: 1) distributed array of in-line fiber Bragg gratings (FBGs) sensors sensitive to strain, vibration, and acoustic emissions, 2) adaptive spectral demodulation of FBG sensor dynamic signals using two-wave mixing interferometry on photorefractive semiconductors, and 3) integration of all the sensor system passive and active optoelectronic components within a 0.5-cm x 1-cm photonic integrated circuit microchip. The adaptive TWM demodulation methodology allows the measurement of dynamic high frequnency acoustic emission events, while compensating for passive quasi-static strain and temperature drifts. It features a compact, low power, environmentally robust 1-inch x 1-inch x 4-inch small form factor (SFF) package with no moving parts. The FAESense™ interrogation system is microprocessor-controlled using high data rate signal processing electronics for the FBG sensors calibration, temperature compensation and the detection and analysis of acoustic emission signals. Its miniaturized package, low power operation, state-of-the-art data communications, and low cost makes it a very attractive solution for a large number of applications in naval and maritime industries, aerospace, civil structures, the oil and chemical industry, and for homeland security applications.

  5. Dielectric oil-based polymer actuator for improved thickness strain and breakdown voltage

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Min Sung; Yamamoto, Akio [Dept. of Precision Engineering, School of Engineering, The University of Tokyo, Tokyo (Japan)

    2016-09-15

    Dielectric elastomer actuators (DEAs) have been increasingly investigated as alternative actuators to conventional ones. However, DEAs suffer from high rates of premature failure. Therefore, this study proposes a dielectric oil-based polymer actuator, also called a Dielectric liquid actuator (DLA), to compensate for the drawbacks of DEAs. DLA was experimentally compared with conventional DEAs. Results showed that DLA successfully prevented thermal runaway at defects in the electrode and excessive thinning of the film, resulting in increased breakdown voltage. Consequently, premature failure was inhibited, and the performance was improved. The breakdown voltages of DLA and DEA were 6000 and 2000 V, respectively, and their maximum thickness strains were 49.5% and 37.5%, respectively.

  6. Dielectric oil-based polymer actuator for improved thickness strain and breakdown voltage

    International Nuclear Information System (INIS)

    Cho, Min Sung; Yamamoto, Akio

    2016-01-01

    Dielectric elastomer actuators (DEAs) have been increasingly investigated as alternative actuators to conventional ones. However, DEAs suffer from high rates of premature failure. Therefore, this study proposes a dielectric oil-based polymer actuator, also called a Dielectric liquid actuator (DLA), to compensate for the drawbacks of DEAs. DLA was experimentally compared with conventional DEAs. Results showed that DLA successfully prevented thermal runaway at defects in the electrode and excessive thinning of the film, resulting in increased breakdown voltage. Consequently, premature failure was inhibited, and the performance was improved. The breakdown voltages of DLA and DEA were 6000 and 2000 V, respectively, and their maximum thickness strains were 49.5% and 37.5%, respectively

  7. Multipoint fiber-optic laser-ultrasonic actuator based on fiber core-opened tapers.

    Science.gov (United States)

    Tian, Jiajun; Dong, Xiaolong; Gao, Shimin; Yao, Yong

    2017-11-27

    In this study, a novel fiber-optic, multipoint, laser-ultrasonic actuator based on fiber core-opened tapers (COTs) is proposed and demonstrated. The COTs were fabricated by splicing single-mode fibers using a standard fiber splicer. A COT can effectively couple part of a core mode into cladding modes, and the coupling ratio can be controlled by adjusting the taper length. Such characteristics are used to obtain a multipoint, laser-ultrasonic actuator with balanced signal strength by reasonably controlling the taper lengths of the COTs. As a prototype, we constructed an actuator that generated ultrasound at four points with a balanced ultrasonic strength by connecting four COTs with coupling ratios of 24.5%, 33.01%, 49.51%, and 87.8% in a fiber link. This simple-to-fabricate, multipoint, laser-ultrasonic actuator with balanced ultrasound signal strength has potential applications in fiber-optic ultrasound testing technology.

  8. A spongy graphene based bimorph actuator with ultra-large displacement towards biomimetic application.

    Science.gov (United States)

    Hu, Ying; Lan, Tian; Wu, Guan; Zhu, Zicai; Chen, Wei

    2014-11-07

    Bimorph actuators, consisting of two layers with asymmetric expansion and generating bending displacement, have been widely researched. Their actuation performances greatly rely on the difference of coefficients of thermal expansion (CTE) between the two material layers. Here, by introducing a spongy graphene (sG) paper with a large negative CTE as well as high electrical-to-thermal properties, an electromechanical sG/PDMS bimorph actuator is designed and fabricated, showing an ultra-large bending displacement output under low voltage stimulation (curvature of about 1.2 cm(-1) at 10 V for 3 s), a high displacement-to-length ratio (∼0.79), and vibration motion at AC voltage (up to 10 Hz), which is much larger and faster than that of the other electromechanical bimorph actuators. Based on the sG/PDMS bimorph serving as the "finger", a mechanical gripper is constructed to realize the fast manipulation of the objects under 0.1 Hz square wave voltage stimulation (0-8 V). The designed bimorph actuator coupled with ultra-large bending displacement, low driven voltage, and the ease of fabrication may open up substantial possibilities for the utilization of electromechanical actuators in practical biomimetic device applications.

  9. Multistable wireless micro-actuator based on antagonistic pre-shaped double beams

    International Nuclear Information System (INIS)

    Liu, X; Lamarque, F; Doré, E; Pouille, P

    2015-01-01

    This paper presents a monolithic multistable micro-actuator based on antagonistic pre-shaped double beams. The designed micro-actuator is formed by two rows of bistable micro-actuators providing four stable positions. The bistable mechanism for each row is a pair of antagonistic pre-shaped beams. This bistable mechanism has an easier pre-load operation compared to the pre-compressed bistable beams method. Furthermore, it solves the asymmetrical force output problem of parallel pre-shaped bistable double beams. At the same time, the geometrical limit is lower than parallel pre-shaped bistable double beams, which ensures a smaller stroke of the micro-actuator with the same dimensions. The designed micro-actuator is fabricated using laser cutting machine on medium density fiberboard (MDF). The bistability and merits of antagonistic pre-shaped double beams are experimentally validated. Finally, a contactless actuation test is performed using 660 nm wavelength laser heating shape memory alloy (SMA) active elements. (paper)

  10. Multistable wireless micro-actuator based on antagonistic pre-shaped double beams

    Science.gov (United States)

    Liu, X.; Lamarque, F.; Doré, E.; Pouille, P.

    2015-07-01

    This paper presents a monolithic multistable micro-actuator based on antagonistic pre-shaped double beams. The designed micro-actuator is formed by two rows of bistable micro-actuators providing four stable positions. The bistable mechanism for each row is a pair of antagonistic pre-shaped beams. This bistable mechanism has an easier pre-load operation compared to the pre-compressed bistable beams method. Furthermore, it solves the asymmetrical force output problem of parallel pre-shaped bistable double beams. At the same time, the geometrical limit is lower than parallel pre-shaped bistable double beams, which ensures a smaller stroke of the micro-actuator with the same dimensions. The designed micro-actuator is fabricated using laser cutting machine on medium density fiberboard (MDF). The bistability and merits of antagonistic pre-shaped double beams are experimentally validated. Finally, a contactless actuation test is performed using 660 nm wavelength laser heating shape memory alloy (SMA) active elements.

  11. Tabu Search-based Synthesis of Digital Microfluidic Biochips with Dynamically Reconfigurable Non-rectangular Devices

    DEFF Research Database (Denmark)

    Maftei, Elena; Pop, Paul; Madsen, Jan

    2010-01-01

    they are highly reconfigurable and scalable. A digital biochip is composed of a two-dimensional array of cells, together with reservoirs for storing the samples and reagents. Several adjacent cells are dynamically grouped to form a virtual device, on which operations are performed. So far, researchers have...... assumed that throughout its execution, an operation is performed on a rectangular virtual device, whose position remains fixed. However, during the execution of an operation, the virtual device can be reconfigured to occupy a different group of cells on the array, forming any shape, not necessarily...... rectangular. In this paper, we present a Tabu Search metaheuristic for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determines the allocation, resource binding, scheduling and placement of the operations in the application...

  12. Integrated reconfigurable microring based silicon WDM receiver for on-chip optical interconnect

    International Nuclear Information System (INIS)

    Shen, Ao; Yang, Long-Zhi; Dai, Ting-Ge; Hao, Yin-Lei; Jiang, Xiao-Qing; Yang, Jian-Yi; Qiu, Chen

    2015-01-01

    We demonstrate an integrated reconfigurable wavelength division multiplexing receiver on the silicon-on-insulator (SOI) platform. The receiver is composed of a 1 × 8 thermally tunable microring resonator filter and Ge–Si photodetectors. With low thermal tuning powers the channel allocation of the receiver can be reconfigured with high accuracy and flexibility. The thermal tuning efficiency is approximately 8 mW nm −1 . We show eight-channel configurations with channel spacing of 100 GHz and 50 GHz and a configuration in which all eight channels cover an entire free spectral range of the ring with uniform channel spacing of 1.2 nm. Each channel can receive high-quality signals with a data rate of up to 13.5 Gb s −1 ; thus an aggregate data rate higher than 100 Gb s −1 can be achieved. (paper)

  13. WDM Optical Access Network for Full-Duplex and Reconfigurable Capacity Assignment Based on PolMUX Technique

    Directory of Open Access Journals (Sweden)

    Jose Mora

    2014-12-01

    Full Text Available We present a novel bidirectional WDM-based optical access network featuring reconfigurable capacity assignment. The architecture relies on the PolMUX technique allowing a compact, flexible, and bandwidth-efficient router in addition to source-free ONUs and color-less ONUs for cost/complexity minimization. Moreover, the centralized architecture contemplates remote management and control of polarization. High-quality transmission of digital signals is demonstrated through different routing scenarios where all channels are dynamically assigned in both downlink and uplink directions.

  14. Inverse grey-box model-based control of a dielectric elastomer actuator

    DEFF Research Database (Denmark)

    Jones, Richard William; Sarban, Rahimullah

    2012-01-01

    control performance across the operating range of the DE actuator, a gain scheduling term, which linearizes the operating characteristics of the tubular dielectric elastomer actuator, is developed and implemented in series with the IMC controller. The IMC-based approach is investigated for servo control......An accurate physical-based electromechanical model of a commercially available tubular dielectric elastomer (DE) actuator has been developed and validated. In this contribution, the use of the physical-based electromechanical model to formulate a model-based controller is examined. The choice...... of control scheme was dictated by the desire for transparency in both controller design and operation. The internal model control (IMC) approach was chosen. In this particular application, the inverse of the linearized form of the grey-box model is used to formulate the IMC controller. To ensure consistent...

  15. Secure computing on reconfigurable systems

    OpenAIRE

    Fernandes Chaves, R.J.

    2007-01-01

    This thesis proposes a Secure Computing Module (SCM) for reconfigurable computing systems. SC provides a protected and reliable computational environment, where data security and protection against malicious attacks to the system is assured. SC is strongly based on encryption algorithms and on the attestation of the executed functions. The use of SC on reconfigurable devices has the advantage of being highly adaptable to the application and the user requirements, while providing high performa...

  16. The Actuator Fault Diagnosis Based on the Valve Friction

    Directory of Open Access Journals (Sweden)

    Jiajiang Li

    2014-08-01

    Full Text Available Control valve (actuator is the frequently moving terminal Instrument of the control system. To avoid the leaking of the actuator, there is packing at the moving parts. However, the friction caused by the packing can do harm to the control of the system. The washing effect of the media, high temperature, high pressure, frequent movement and other effects can result in the leaking of the packing and the deformation of the valve stem, which causes the change of the friction. The study of the control of the friction has always been an interesting topic in the industry. In this paper, we theoretically analyze the relationship of the friction of the packing and the static performance of the control valve, and offer a method to check the quality of the moving parts by attaching a strain gage (strain rosette to the empty part of the valve stem. This method has been demonstrated via experiment and a method to do error detection is provided at last.

  17. High-cycle electromechanical aging of dielectric elastomer actuators with carbon-based electrodes

    Science.gov (United States)

    de Saint-Aubin, C. A.; Rosset, S.; Schlatter, S.; Shea, H.

    2018-07-01

    We present high-cycle aging tests of dielectric elastomer actuators (DEAs) based on silicone elastomers, reporting on the time-evolution of actuation strain and of electrode resistance over millions of cycles. We compare several types of carbon-based electrodes, and for the first time show how the choice of electrode has a dramatic influence on DEA aging. An expanding circle DEA configuration is used, consisting of a commercial silicone membrane with the following electrodes: commercial carbon grease applied manually, solvent-diluted carbon grease applied by stamping (pad printing), loose carbon black powder applied manually, carbon black powder suspension applied by inkjet-printing, and conductive silicone-carbon composite applied by stamping. The silicone-based DEAs with manually applied carbon grease electrodes show the shortest lifetime of less than 105 cycles at 5% strain, while the inkjet-printed carbon powder and the stamped silicone-carbon composite make for the most reliable devices, with lifetimes greater than 107 cycles at 5% strain. These results are valid for the specific dielectric and electrode configurations that were tested: using other dielectrics or electrode formulations would lead to different lifetimes and failure modes. We find that aging (as seen in the change in resistance and in actuation strain versus cycle number) is independent of the actuation frequency from 10 Hz to 200 Hz, and depends on the total accumulated time the DEA spends in an actuated state.

  18. PVC gel soft actuator-based wearable assist wear for hip joint support during walking

    Science.gov (United States)

    Li, Yi; Hashimoto, Minoru

    2017-12-01

    Plasticized polyvinyl chloride (PVC) gel and mesh electrode-based soft actuators have considerable potential to provide new types of artificial muscle, exhibiting similar responsiveness to biological muscle in air, >10% deformation, >90 kPa output stress, variable stiffness, long cycle life (>5 million cycles), and low power consumption. We have designed and fabricated a prototype of walking assist wear using the PVC gel actuator in previous study. The system has several advantages compared with traditional motor-based exoskeletons, including lower weight and power consumption, and no requirement for rigid external structures that constrain the wearer’s joints. In this study, we designed and established a control and power system to making the whole system portable and wearable outdoors. And we designed two control strategies based on the characteristics of the assist wear and the biological kinematics. In a preliminary experimental evaluation, a hemiparetic stroke patient performed a 10 m to-and-fro straight line walking task with and without assist wear on the affected side. We found that the assist wear enabled natural movement, increasing step length and decreasing muscular activity during straight line walking. We demonstrated that the assistance effect could be adjusted by controlling the on-off time of the PVC gel soft actuators. The results show the effectiveness of the proposed system and suggest the feasibility of PVC gel soft actuators for developing practical soft wearable assistive devices, informing the development of future wearable robots and the other soft actuator technologies for human movement assistance and rehabilitation.

  19. Smart materials-based actuators at the micronano-scale characterization, control, and applications

    CERN Document Server

    2013-01-01

    Smart Materials-Based Actuators at the Micro/Nano-Scale: Characterization, Control, and Applications gives a state of the art of emerging techniques to the characterization and control of actuators based on smart materials working at the micro/nano scale. The book aims to characterize some commonly used structures based on piezoelectric and electroactive polymeric actuators and also focuses on various and emerging techniques employed to control them. This book also includes two of the most emerging topics and applications: nanorobotics and cells micro/nano-manipulation. This book: Provides both theoretical and experimental results Contains complete information from characterization, modeling, identification, control to final applications for researchers and engineers that would like to model, characterize, control and apply their own micro/nano-systems Discusses applications such as microrobotics and their control, design and fabrication of microsystems, microassembly and its automation, nanorobotics and thei...

  20. A new hybrid evolutionary algorithm based on new fuzzy adaptive PSO and NM algorithms for Distribution Feeder Reconfiguration

    International Nuclear Information System (INIS)

    Niknam, Taher; Azadfarsani, Ehsan; Jabbari, Masoud

    2012-01-01

    Highlights: ► Network reconfiguration is a very important way to save the electrical energy. ► This paper proposes a new algorithm to solve the DFR. ► The algorithm combines NFAPSO with NM. ► The proposed algorithm is tested on two distribution test feeders. - Abstract: Network reconfiguration for loss reduction in distribution system is a very important way to save the electrical energy. This paper proposes a new hybrid evolutionary algorithm to solve the Distribution Feeder Reconfiguration problem (DFR). The algorithm is based on combination of a New Fuzzy Adaptive Particle Swarm Optimization (NFAPSO) and Nelder–Mead simplex search method (NM) called NFAPSO–NM. In the proposed algorithm, a new fuzzy adaptive particle swarm optimization includes two parts. The first part is Fuzzy Adaptive Binary Particle Swarm Optimization (FABPSO) that determines the status of tie switches (open or close) and second part is Fuzzy Adaptive Discrete Particle Swarm Optimization (FADPSO) that determines the sectionalizing switch number. In other side, due to the results of binary PSO(BPSO) and discrete PSO(DPSO) algorithms highly depends on the values of their parameters such as the inertia weight and learning factors, a fuzzy system is employed to adaptively adjust the parameters during the search process. Moreover, the Nelder–Mead simplex search method is combined with the NFAPSO algorithm to improve its performance. Finally, the proposed algorithm is tested on two distribution test feeders. The results of simulation show that the proposed method is very powerful and guarantees to obtain the global optimization.

  1. Leveraging Disturbance Observer Based Torque Control for Improved Impedance Rendering with Series Elastic Actuators

    Science.gov (United States)

    Mehling, Joshua S.; Holley, James; O'Malley, Marcia K.

    2015-01-01

    The fidelity with which series elastic actuators (SEAs) render desired impedances is important. Numerous approaches to SEA impedance control have been developed under the premise that high-precision actuator torque control is a prerequisite. Indeed, the design of an inner torque compensator has a significant impact on actuator impedance rendering. The disturbance observer (DOB) based torque control implemented in NASA's Valkyrie robot is considered here and a mathematical model of this torque control, cascaded with an outer impedance compensator, is constructed. While previous work has examined the impact a disturbance observer has on torque control performance, little has been done regarding DOBs and impedance rendering accuracy. Both simulation and a series of experiments are used to demonstrate the significant improvements possible in an SEA's ability to render desired dynamic behaviors when utilizing a DOB. Actuator transparency at low impedances is improved, closed loop hysteresis is reduced, and the actuator's dynamic response to both commands and interaction torques more faithfully matches that of the desired model. All of this is achieved by leveraging DOB based control rather than increasing compensator gains, thus making improved SEA impedance control easier to achieve in practice.

  2. Magnetic actuator for the control and mixing of magnetic bead-based reactions on-chip.

    Science.gov (United States)

    Berenguel-Alonso, Miguel; Granados, Xavier; Faraudo, Jordi; Alonso-Chamarro, Julián; Puyol, Mar

    2014-10-01

    While magnetic bead (MB)-based bioassays have been implemented in integrated devices, their handling on-chip is normally either not optimal--i.e. only trapping is achieved, with aggregation of the beads--or requires complex actuator systems. Herein, we describe a simple and low-cost magnetic actuator to trap and move MBs within a microfluidic chamber in order to enhance the mixing of a MB-based reaction. The magnetic actuator consists of a CD-shaped plastic unit with an arrangement of embedded magnets which, when rotating, generate the mixing. The magnetic actuator has been used to enhance the amplification reaction of an enzyme-linked fluorescence immunoassay to detect Escherichia coli O157:H7 whole cells, an enterohemorrhagic strain, which have caused several outbreaks in food and water samples. A 2.7-fold sensitivity enhancement was attained with a detection limit of 603 colony-forming units (CFU) /mL, when employing the magnetic actuator.

  3. Plasma-based actuators for turbulent boundary layer control in transonic flow

    Science.gov (United States)

    Budovsky, A. D.; Polivanov, P. A.; Vishnyakov, O. I.; Sidorenko, A. A.

    2017-10-01

    The study is devoted to development of methods for active control of flow structure typical for the aircraft wings in transonic flow with turbulent boundary layer. The control strategy accepted in the study was based on using of the effects of plasma discharges interaction with miniature geometrical obstacles of various shapes. The conceptions were studied computationally using 3D RANS, URANS approaches. The results of the computations have shown that energy deposition can significantly change the flow pattern over the obstacles increasing their influence on the flow in boundary layer region. Namely, one of the most interesting and promising data were obtained for actuators basing on combination of vertical wedge with asymmetrical plasma discharge. The wedge considered is aligned with the local streamlines and protruding in the flow by 0.4-0.8 of local boundary layer thickness. The actuator produces negligible distortion of the flow at the absence of energy deposition. Energy deposition along the one side of the wedge results in longitudinal vortex formation in the wake of the actuator providing momentum exchange in the boundary layer. The actuator was manufactured and tested in wind tunnel experiments at Mach number 1.5 using the model of flat plate. The experimental data obtained by PIV proved the availability of the actuator.

  4. Controller Reconfiguration through Terminal Connections  based on Closed-loop System Identification

    DEFF Research Database (Denmark)

    Trangbæk, K

    2009-01-01

     Often, when a controlled plant is modified, e.g. if a new sensor or  actuator becomes available, it is desirable to retain the existing  controllers and apply the new control capabilities in a gradual,  online fashion rather than decommissioning the entire existing system  and replacing it with ...

  5. An electroactive conducting polymer actuator based on NBR/RTIL solid polymer electrolyte

    Science.gov (United States)

    Cho, M. S.; Seo, H. J.; Nam, J. D.; Choi, H. R.; Koo, J. C.; Lee, Y.

    2007-04-01

    This paper reports the fabrication of a dry-type conducting polymer actuator using nitrile rubber (NBR) as the base material in a solid polymer electrolyte. The conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the NBR layer by using a chemical oxidation polymerization technique. Room-temperature ionic liquids (RTIL) based on imidazolium salts, e.g. 1-butyl-3-methyl imidazolium X (where X = BF4-, PF6-, (CF3SO2)2N-), were absorbed into the composite film. The compatibility between the ionic liquids and the NBR polymer was confirmed by DMA. The effect of the anion size of the ionic liquids on the displacement of the actuator was examined. The displacement increased with increasing anion size of the ionic liquids. The cyclic voltammetry responses and the redox switching dynamics of the actuators were examined in different ionic liquids.

  6. Magnetostrictive actuator-based micropositioner and its application in turning

    Science.gov (United States)

    Kanizar, William L.; Liu, Dongming; Moon, Kee S.; Sutherland, John W.

    1996-05-01

    The surface finish of a turned part is primarily generated from process parameters such as feed, tool geometry, and cutting speed. A micropositioner system utilizing a magnetostrictive material, Terfenol-D, as a linear motor is presented as a means to actively control the process. The system has an actuator clamped in a flexor that is rigid in the feed and main cutting force directions, yet is flexible in the radial direction. Using control algorithms implemented on a digital computer, the system can provide a means to compensate for deleterious vibrations. The system has also been used to manipulate the tool position in the radial direction so that non-circular turning can be accomplished.

  7. Opto-VLSI-based reconfigurable free-space optical interconnects architecture

    DEFF Research Database (Denmark)

    Aljada, Muhsen; Alameh, Kamal; Chung, Il-Sug

    2007-01-01

    is the Opto-VLSI processor which can be driven by digital phase steering and multicasting holograms that reconfigure the optical interconnects between the input and output ports. The optical interconnects architecture is experimentally demonstrated at 2.5 Gbps using high-speed 1×3 VCSEL array and 1......×3 photoreceiver array in conjunction with two 1×4096 pixel Opto-VLSI processors. The minimisation of the crosstalk between the output ports is achieved by appropriately aligning the VCSEL and PD elements with respect to the Opto-VLSI processors and driving the latter with optimal steering phase holograms....

  8. An efficient hybrid evolutionary algorithm based on PSO and HBMO algorithms for multi-objective Distribution Feeder Reconfiguration

    Energy Technology Data Exchange (ETDEWEB)

    Niknam, Taher [Electronic and Electrical Engineering Department, Shiraz University of Technology, Shiraz (Iran)

    2009-08-15

    This paper introduces a robust searching hybrid evolutionary algorithm to solve the multi-objective Distribution Feeder Reconfiguration (DFR). The main objective of the DFR is to minimize the real power loss, deviation of the nodes' voltage, the number of switching operations, and balance the loads on the feeders. Because of the fact that the objectives are different and no commensurable, it is difficult to solve the problem by conventional approaches that may optimize a single objective. This paper presents a new approach based on norm3 for the DFR problem. In the proposed method, the objective functions are considered as a vector and the aim is to maximize the distance (norm2) between the objective function vector and the worst objective function vector while the constraints are met. Since the proposed DFR is a multi objective and non-differentiable optimization problem, a new hybrid evolutionary algorithm (EA) based on the combination of the Honey Bee Mating Optimization (HBMO) and the Discrete Particle Swarm Optimization (DPSO), called DPSO-HBMO, is implied to solve it. The results of the proposed reconfiguration method are compared with the solutions obtained by other approaches, the original DPSO and HBMO over different distribution test systems. (author)

  9. Construction of a Fish-like Robot Based on High Performance Graphene/PVDF Bimorph Actuation Materials.

    Science.gov (United States)

    Xiao, Peishuang; Yi, Ningbo; Zhang, Tengfei; Huang, Yi; Chang, Huicong; Yang, Yang; Zhou, Ying; Chen, Yongsheng

    2016-06-01

    Smart actuators have many potential applications in various areas, so the development of novel actuation materials, with facile fabricating methods and excellent performances, are still urgent needs. In this work, a novel electromechanical bimorph actuator constituted by a graphene layer and a PVDF layer, is fabricated through a simple yet versatile solution approach. The bimorph actuator can deflect toward the graphene side under electrical stimulus, due to the differences in coefficient of thermal expansion between the two layers and the converse piezoelectric effect and electrostrictive property of the PVDF layer. Under low voltage stimulus, the actuator (length: 20 mm, width: 3 mm) can generate large actuation motion with a maximum deflection of about 14.0 mm within 0.262 s and produce high actuation stress (more than 312.7 MPa/g). The bimorph actuator also can display reversible swing behavior with long cycle life under high frequencies. on this basis, a fish-like robot that can swim at the speed of 5.02 mm/s is designed and demonstrated. The designed graphene-PVDF bimorph actuator exhibits the overall novel performance compared with many other electromechanical avtuators, and may contribute to the practical actuation applications of graphene-based materials at a macro scale.

  10. Construction of a Fish‐like Robot Based on High Performance Graphene/PVDF Bimorph Actuation Materials

    Science.gov (United States)

    Xiao, Peishuang; Yi, Ningbo; Zhang, Tengfei; Chang, Huicong; Yang, Yang; Zhou, Ying

    2016-01-01

    Smart actuators have many potential applications in various areas, so the development of novel actuation materials, with facile fabricating methods and excellent performances, are still urgent needs. In this work, a novel electromechanical bimorph actuator constituted by a graphene layer and a PVDF layer, is fabricated through a simple yet versatile solution approach. The bimorph actuator can deflect toward the graphene side under electrical stimulus, due to the differences in coefficient of thermal expansion between the two layers and the converse piezoelectric effect and electrostrictive property of the PVDF layer. Under low voltage stimulus, the actuator (length: 20 mm, width: 3 mm) can generate large actuation motion with a maximum deflection of about 14.0 mm within 0.262 s and produce high actuation stress (more than 312.7 MPa/g). The bimorph actuator also can display reversible swing behavior with long cycle life under high frequencies. on this basis, a fish‐like robot that can swim at the speed of 5.02 mm/s is designed and demonstrated. The designed graphene‐PVDF bimorph actuator exhibits the overall novel performance compared with many other electromechanical avtuators, and may contribute to the practical actuation applications of graphene‐based materials at a macro scale. PMID:27818900

  11. Electromechanical actuator with controllable motion, fast response rate, and high-frequency resonance based on graphene and polydiacetylene.

    Science.gov (United States)

    Liang, Jiajie; Huang, Lu; Li, Na; Huang, Yi; Wu, Yingpeng; Fang, Shaoli; Oh, Jiyoung; Kozlov, Mikhail; Ma, Yanfeng; Li, Feifei; Baughman, Ray; Chen, Yongsheng

    2012-05-22

    Although widely investigated, novel electromechanical actuators with high overall actuation performance are still in urgent need for various practical and scientific applications, such as robots, prosthetic devices, sensor switches, and sonar projectors. In this work, combining the properties of unique environmental perturbations-actuated deformational isomerization of polydiacetylene (PDA) and the outstanding intrinsic features of graphene together for the first time, we design and fabricate an electromechanical bimorph actuator composed of a layer of PDA crystal and a layer of flexible graphene paper through a simple yet versatile solution approach. Under low applied direct current (dc), the graphene-PDA bimorph actuator with strong mechanical strength can generate large actuation motion (curvature is about 0.37 cm(-1) under a current density of 0.74 A/mm(2)) and produce high actuation stress (more than 160 MPa/g under an applied dc of only 0.29 A/mm(2)). When applying alternating current (ac), this actuator can display reversible swing behavior with long cycle life under high frequencies even up to 200 Hz; significantly, while the frequency and the value of applied ac and the state of the actuators reach an appropriate value, the graphene-PDA actuator can produce a strong resonance and the swing amplitude will jump to a peak value. Moreover, this stable graphene-PDA actuator also demonstrates rapidly and partially reversible electrochromatic phenomenon when applying an ac. Two mechanisms-the dominant one, electric-induced deformation, and a secondary one, thermal-induced expansion of PDA-are proposed to contribute to these interesting actuation performances of the graphene-PDA actuators. On the basis of these results, a mini-robot with controllable direction of motion based on the graphene-PDA actuator is designed to illustrate the great potential of our discoveries for practical use. Combining the unique actuation mechanism and many outstanding properties of

  12. Surface texture change on-demand and microfluidic devices based on thickness mode actuation of dielectric elastomer actuators (DEAs)

    Science.gov (United States)

    Ankit, Ankit; Nguyen, Anh Chien; Mathews, Nripan

    2017-04-01

    Tactile feedback devices and microfluidic devices have huge significance in strengthening the area of robotics, human machine interaction and low cost healthcare. Dielectric Elastomer Actuators (DEAs) are an attractive alternative for both the areas; offering the advantage of low cost and simplistic fabrication in addition to the high actuation strains. The inplane deformations produced by the DEAs can be used to produce out-of-plane deformations by what is known as the thickness mode actuation of DEAs. The thickness mode actuation is achieved by adhering a soft passive layer to the DEA. This enables a wide area of applications in tactile applications without the need of complex systems and multiple actuators. But the thickness mode actuation has not been explored enough to understand how the deformations can be improved without altering the material properties; which is often accompanied with increased cost and a trade off with other closely associated material properties. We have shown the effect of dimensions of active region and non-active region in manipulating the out-of-plane deformation. Making use of this, we have been able to demonstrate large area devices and complex patterns on the passive top layer for the surface texture change on-demand applications. We have also been able to demonstrate on-demand microfluidic channels and micro-chambers without the need of actually fabricating the channels; which is a cost incurring and cumbersome process.

  13. Compliant actuation based on dielectric elastomers for a force-feedback device: modeling and experimental evaluation

    Directory of Open Access Journals (Sweden)

    R. Vertechy

    2013-01-01

    Full Text Available Thanks to their large power densities, low costs and shock-insensitivity, Dielectric Elastomers (DE seem to be a promising technology for the implementation of light and compact force-feedback devices such as, for instance, haptic interfaces. Nonetheless, the development of these kinds of DE-based systems is not trivial owing to the relevant dissipative phenomena that affect the DE when subjected to rapidly changing deformations. In this context, the present paper addresses the development of a force feedback controller for an agonist-antagonist linear actuator composed of a couple of conically-shaped DE films and a compliant mechanism behaving as a negative-rate bias spring. The actuator is firstly modeled accounting for the visco-hyperelastic nature of the DE material. The model is then linearized and employed for the design of a force controller. The controller employs a position sensor, which determines the actuator configuration, and a force sensor, which measures the interaction force that the actuator exchanges with the environment. In addition, an optimum full-state observer is also implemented, which enables both accurate estimation of the time-dependent behavior of the elastomeric material and adequate suppression of the sensor measurement noise. Preliminary experimental results are provided to validate the proposed actuator-controller architecture.

  14. Thermally Driven Photonic Actuator Based on Silica Opal Photonic Crystal with Liquid Crystal Elastomer.

    Science.gov (United States)

    Xing, Huihui; Li, Jun; Shi, Yang; Guo, Jinbao; Wei, Jie

    2016-04-13

    We have developed a novel thermoresponsive photonic actuator based on three-dimensional SiO2 opal photonic crystals (PCs) together with liquid crystal elastomers (LCEs). In the process of fabrication of such a photonic actuator, the LCE precursor is infiltrated into the SiO2 opal PC followed by UV light-induced photopolymerization, thereby forming the SiO2 opal PC/LCE composite film with a bilayer structure. We find that this bilayer composite film simultaneously exhibits actuation behavior as well as the photonic band gap (PBG) response to external temperature variation. When the SiO2 opal PC/LCE composite film is heated, it exhibits a considerable bending deformation, and its PBG shifts to a shorter wavelength at the same time. In addition, this actuation is quite fast, reversible, and highly repeatable. The thermoresponsive behavior of the SiO2 opal PC/LCE composite films mainly derives from the thermal-driven change of nematic order of the LCE layer which leads to the asymmetric shrinkage/expansion of the bilayer structure. These results will be of interest in designing optical actuator systems for environment-temperature detection.

  15. Design and implementation of a reconfigurable mixed-signal SoC based on field programmable analog arrays

    Science.gov (United States)

    Liu, Lintao; Gao, Yuhan; Deng, Jun

    2017-11-01

    This work presents a reconfigurable mixed-signal system-on-chip (SoC), which integrates switched-capacitor-based field programmable analog arrays (FPAA), analog-to-digital converter (ADC), digital-to-analog converter, digital down converter , digital up converter, 32-bit reduced instruction-set computer central processing unit (CPU) and other digital IPs on a single chip with 0.18 μm CMOS technology. The FPAA intellectual property could be reconfigured as different function circuits, such as gain amplifier, divider, sine generator, and so on. This single-chip integrated mixed-signal system is a complete modern signal processing system, occupying a die area of 7 × 8 mm 2 and consuming 719 mW with a clock frequency of 150 MHz for CPU and 200 MHz for ADC/DAC. This SoC chip can help customers to shorten design cycles, save board area, reduce the system power consumption and depress the system integration risk, which would afford a big prospect of application for wireless communication. Project supported by the National High Technology and Development Program of China (No. 2012AA012303).

  16. Reconfigurable and ultra-sensitive in-line Mach-Zehnder interferometer based on the fusion of microfiber and microfluid

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Shecheng [Key Laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071 (China); Institute of Micro and Nano Optics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Zhang, Weigang, E-mail: zhangwg@nankai.edu.cn, E-mail: haozhang@nankai.edu.cn; Zhang, Hao, E-mail: zhangwg@nankai.edu.cn, E-mail: haozhang@nankai.edu.cn [Key Laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071 (China); Zhang, Chonglei [Institute of Micro and Nano Optics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China)

    2015-02-23

    A reconfigurable Mach-Zenhnder interferometer (MZI) based on a microfluidic cavity (MFC) constructed by embedding a microfiber between two segments of single-mode fibers with pre-designed lateral offset has been proposed and experimentally demonstrated. The MFC serves as an interference arm with an eccentric annular cross section and allows convenient sample (gas or liquids) replacement procedure. The microfiber works as the other interference arm that provides the proposed device with ease of reconstruction and also enhances the force sensitivity. The re-configurability and the ultra-wide tuning sensitivity range are demonstrated by immersing the MZI constructed with a 484 μm-long-MFC and a microfiber 44 μm in diameter in different droplets. Ultrahigh sensitivities of 34.65 nm/°C (∼88 380 nm/RIU) and −493.7 nm/N (∼−590 pm/με) are experimentally achieved using a droplet with a refractive index of ∼1.44.

  17. Reconfigurable and ultra-sensitive in-line Mach-Zehnder interferometer based on the fusion of microfiber and microfluid

    International Nuclear Information System (INIS)

    Gao, Shecheng; Zhang, Weigang; Zhang, Hao; Zhang, Chonglei

    2015-01-01

    A reconfigurable Mach-Zenhnder interferometer (MZI) based on a microfluidic cavity (MFC) constructed by embedding a microfiber between two segments of single-mode fibers with pre-designed lateral offset has been proposed and experimentally demonstrated. The MFC serves as an interference arm with an eccentric annular cross section and allows convenient sample (gas or liquids) replacement procedure. The microfiber works as the other interference arm that provides the proposed device with ease of reconstruction and also enhances the force sensitivity. The re-configurability and the ultra-wide tuning sensitivity range are demonstrated by immersing the MZI constructed with a 484 μm-long-MFC and a microfiber 44 μm in diameter in different droplets. Ultrahigh sensitivities of 34.65 nm/°C (∼88 380 nm/RIU) and −493.7 nm/N (∼−590 pm/με) are experimentally achieved using a droplet with a refractive index of ∼1.44

  18. Powered Upper Limb Orthosis Actuation System Based on Pneumatic Artificial Muscles

    Science.gov (United States)

    Chakarov, Dimitar; Veneva, Ivanka; Tsveov, Mihail; Venev, Pavel

    2018-03-01

    The actuation system of a powered upper limb orthosis is studied in the work. To create natural safety in the mutual "man-robot" interaction, an actuation system based on pneumatic artificial muscles (PAM) is selected. Experimentally obtained force/contraction diagrams for bundles, consisting of different number of muscles are shown in the paper. The pooling force and the stiffness of the pneumatic actuators is assessed as a function of the number of muscles in the bundle and the supply pressure. Joint motion and torque is achieved by antagonistic actions through pulleys, driven by bundles of pneumatic muscles. Joint stiffness and joint torques are determined on condition of a power balance, as a function of the joint position, pressure, number of muscles and muscles

  19. Helmholtz resonance in a piezoelectric–hydraulic pump-based hybrid actuator

    International Nuclear Information System (INIS)

    Kim, Gi-Woo; Wang, K W

    2011-01-01

    This paper demonstrates that a hydraulically acting Helmholtz resonator can exist in a piezoelectric–hydraulic pump (PHP) based hybrid actuator, which in turn affects the volumetric efficiency of the PHP. The simulation and experimental results illustrate the effect of Helmholtz resonance on the flow rate performance of the PHP. The study also shows how to shift the Helmholtz resonant frequency to a higher value through changing parameters such as the cylinder diameter and the effective bulk modulus of the working fluid, which will improve the volumetric efficiency and broaden the operating frequency range of the PHP actuator

  20. A solid state actuator based on polypyrrole (PPy) and a solid electrolyte NBR working in air

    Science.gov (United States)

    Cho, Misuk; Nam, Jaedo; Choi, Hyouk Ryeol; Koo, Jachoon; Lee, Youngkwan

    2005-05-01

    The solid polymer electrolyte based conducting polymer actuator was presented. In the preparation of acutuator module, an ionic liquid impregnated a synthetic rubber (NBR) and PPy were used as a solid polymer electrolyte and conducting polymer, respectively. An ionic liquid, 1-butyl-3-methylimidazolium bis (trifluoromethyl sulfonyl)imide (BMITFSI) is gradually dispersed into the NBR film and the conducting polymer, PPy was synthesized on the surface of NBR. The ionic conductivity of new type solid polymer electrolyte as a function of the immersion time was investigated. The cyclic voltammetry responsed and the redox switching dynamics of PEDOT in NBR matrix were studied. The displacement of the actuator was measured by laser beam.

  1. Low-Power Silicon-based Thermal Sensors and Actuators for Chemical Applications

    NARCIS (Netherlands)

    Vereshchagina, E.

    2011-01-01

    In the Hot Silicon project low and ultra-low-power Si-based hot surface devices have been developed, i.e. thermal sensors and actuators, for application in catalytic gas micro sensors, micro- and nano- calorimeters. This work include several scientific and technological aspects: • Design and

  2. Active control of massively separated high-speed/base flows with electric arc plasma actuators

    Science.gov (United States)

    DeBlauw, Bradley G.

    The current project was undertaken to evaluate the effects of electric arc plasma actuators on high-speed separated flows. Two underlying goals motivated these experiments. The first goal was to provide a flow control technique that will result in enhanced flight performance for supersonic vehicles by altering the near-wake characteristics. The second goal was to gain a broader and more sophisticated understanding of these complex, supersonic, massively-separated, compressible, and turbulent flow fields. The attainment of the proposed objectives was facilitated through energy deposition from multiple electric-arc plasma discharges near the base corner separation point. The control authority of electric arc plasma actuators on a supersonic axisymmetric base flow was evaluated for several actuator geometries, frequencies, forcing modes, duty cycles/on-times, and currents. Initially, an electric arc plasma actuator power supply and control system were constructed to generate the arcs. Experiments were performed to evaluate the operational characteristics, electromagnetic emission, and fluidic effect of the actuators in quiescent ambient air. The maximum velocity induced by the arc when formed in a 5 mm x 1.6 mm x 2 mm deep cavity was about 40 m/s. During breakdown, the electromagnetic emission exhibited a rise and fall in intensity over a period of about 340 ns. After breakdown, the emission stabilized to a near-constant distribution. It was also observed that the plasma formed into two different modes: "high-voltage" and "low-voltage". It is believed that the plasma may be switching between an arc discharge and a glow discharge for these different modes. The two types of plasma do not appear to cause substantial differences on the induced fluidic effects of the actuator. In general, the characterization study provided a greater fundamental understanding of the operation of the actuators, as well as data for computational model comparison. Preliminary investigations

  3. Design challenges for stepper motor actuated microvalve based on fine and micro-machining

    NARCIS (Netherlands)

    Fazal, I.; Elwenspoek, Michael Curt

    2007-01-01

    We present a normally open stepper motor actuated microvalve based on micro and fine-machining technique. In this paper, first we have described how the larger controllable flow range can be achieved with simple micromachining techniques and secondly we have presented the results which show how the

  4. Optimization of Comb-Drive Actuators [Nanopositioners for probe-based data storage and musical MEMS

    NARCIS (Netherlands)

    Engelen, Johannes Bernardus Charles

    2011-01-01

    The era of infinite storage seems near. To reach it, data storage capabilities need to grow, and new storage technologies must be developed.This thesis studies one aspect of one of the emergent storage technologies: optimizing electrostatic combdrive actuation for a parallel probe-based data storage

  5. Kinematics of an in-parallel actuated manipulator based on the Stewart platform mechanism

    Science.gov (United States)

    Williams, Robert L., II

    1992-01-01

    This paper presents kinematic equations and solutions for an in-parallel actuated robotic mechanism based on Stewart's platform. These equations are required for inverse position and resolved rate (inverse velocity) platform control. NASA LaRC has a Vehicle Emulator System (VES) platform designed by MIT which is based on Stewart's platform. The inverse position solution is straight-forward and computationally inexpensive. Given the desired position and orientation of the moving platform with respect to the base, the lengths of the prismatic leg actuators are calculated. The forward position solution is more complicated and theoretically has 16 solutions. The position and orientation of the moving platform with respect to the base is calculated given the leg actuator lengths. Two methods are pursued in this paper to solve this problem. The resolved rate (inverse velocity) solution is derived. Given the desired Cartesian velocity of the end-effector, the required leg actuator rates are calculated. The Newton-Raphson Jacobian matrix resulting from the second forward position kinematics solution is a modified inverse Jacobian matrix. Examples and simulations are given for the VES.

  6. Reconfigurable metamaterials for terahertz wave manipulation

    Science.gov (United States)

    Hashemi, Mohammed R.; Cakmakyapan, Semih; Jarrahi, Mona

    2017-09-01

    Reconfigurable metamaterials have emerged as promising platforms for manipulating the spectral and spatial properties of terahertz waves without being limited by the characteristics of naturally existing materials. Here, we present a comprehensive overview of various types of reconfigurable metamaterials that are utilized to manipulate the intensity, phase, polarization, and propagation direction of terahertz waves. We discuss various reconfiguration mechanisms based on optical, electrical, thermal, and mechanical stimuli while using semiconductors, superconductors, phase-change materials, graphene, and electromechanical structures. The advantages and disadvantages of different reconfigurable metamaterial designs in terms of modulation efficiency, modulation bandwidth, modulation speed, and system complexity are discussed in detail.

  7. Extended state observer-based motion synchronisation control for hybrid actuation system of large civil aircraft

    Science.gov (United States)

    Wang, Xingjian; Shi, Cun; Wang, Shaoping

    2017-07-01

    Hybrid actuation system with dissimilar redundant actuators, which is composed of a hydraulic actuator (HA) and an electro-hydrostatic actuator (EHA), has been applied on modern civil aircraft to improve the reliability. However, the force fighting problem arises due to different dynamic performances between HA and EHA. This paper proposes an extended state observer (ESO)-based motion synchronisation control method. To cope with the problem of unavailability of the state signals, the well-designed ESO is utilised to observe the HA and EHA state variables which are unmeasured. In particular, the extended state of ESO can estimate the lumped effect of the unknown external disturbances acting on the control surface, the nonlinear dynamics, uncertainties, and the coupling term between HA and EHA. Based on the observed states of ESO, motion synchronisation controllers are presented to make HA and EHA to simultaneously track the desired motion trajectories, which are generated by a trajectory generator. Additionally, the unknown disturbances and the coupling terms can be compensated by using the extended state of the proposed ESO. Finally, comparative simulation results indicate that the proposed ESO-based motion synchronisation controller can achieve great force fighting reduction between HA and EHA.

  8. A study of metalized electrode self-clearing in electroactive polymer (EAP) based actuators

    Science.gov (United States)

    Ahmed, Saad; Ounaies, Zoubeida

    2016-04-01

    Electroactive polymer (EAP) based technologies have shown promise in areas such as artificial muscles, actuator, aerospace, medical and soft robotics. Still challenges remain such as low induced forces and defects-driven electrical breakdown, which impede the practical implementation of this technology. Multilayered or stacked configuration can address the low induced force issue whereas self-clearing can be a technique to improve breakdown limit of EAP based actuators. Self-clearing refers to the partial local breakdown of dielectric medium due to the presence of impurities, which in turn results in the evaporation of some of the metalized electrode. After this evaporation, the impurity is cleared and any current path would be safely cut off, which means the actuator continues to perform. It is a widely studied concept in the capacitor community, while it has not been studied much for EAP technologies. In this paper we report a systematic approach to precondition a silver-metalized electroactive polymer (EAP), more specifically P(VDF-TrFE-CTFE) terpolymer, using self-clearing concept. First, we show improvement in the dielectric breakdown strength of EAP based unimorph actuators after pre-clearing the impurities using low electric field (lower than dielectric breakdown of the terpolymer). Inspired by this improvement, we used Weibull statistics to systematically estimate the self-clearing/ preconditioning field needed to clear the defects. Then electrical breakdown experiments are conducted with and without preconditioning the samples to investigate its effect on the breakdown strength of the sample.

  9. Metasurfaces Based on Phase-Change Material as a Reconfigurable Platform for Multifunctional Devices

    Science.gov (United States)

    Raeis-Hosseini, Niloufar; Rho, Junsuk

    2017-01-01

    Integration of phase-change materials (PCMs) into electrical/optical circuits has initiated extensive innovation for applications of metamaterials (MMs) including rewritable optical data storage, metasurfaces, and optoelectronic devices. PCMs have been studied deeply due to their reversible phase transition, high endurance, switching speed, and data retention. Germanium-antimony-tellurium (GST) is a PCM that has amorphous and crystalline phases with distinct properties, is bistable and nonvolatile, and undergoes a reliable and reproducible phase transition in response to an optical or electrical stimulus; GST may therefore have applications in tunable photonic devices and optoelectronic circuits. In this progress article, we outline recent studies of GST and discuss its advantages and possible applications in reconfigurable metadevices. We also discuss outlooks for integration of GST in active nanophotonic metadevices. PMID:28878196

  10. Synthesis of Phase-Only Reconfigurable Linear Arrays Using Multiobjective Invasive Weed Optimization Based on Decomposition

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2014-01-01

    Full Text Available Synthesis of phase-only reconfigurable array aims at finding a common amplitude distribution and different phase distributions for the array to form different patterns. In this paper, the synthesis problem is formulated as a multiobjective optimization problem and solved by a new proposed algorithm MOEA/D-IWO. First, novel strategies are introduced in invasive weed optimization (IWO to make original IWO fit for solving multiobjective optimization problems; then, the modified IWO is integrated into the framework of the recently well proved competitive multiobjective optimization algorithm MOEA/D to form a new competitive MOEA/D-IWO algorithm. At last, two sets of experiments are carried out to illustrate the effectiveness of MOEA/D-IWO. In addition, MOEA/D-IWO is compared with MOEA/D-DE, a new version of MOEA/D. The comparing results show the superiority of MOEA/D-IWO and indicate its potential for solving the antenna array synthesis problems.

  11. Dual-drive Mach-Zehnder modulator-based reconfigurable and transparent spectral conversion for dense wavelength division multiplexing transmissions

    Science.gov (United States)

    Mao, Mingzhi; Qian, Chen; Cao, Bingyao; Zhang, Qianwu; Song, Yingxiong; Wang, Min

    2017-09-01

    A digital signal process enabled dual-drive Mach-Zehnder modulator (DD-MZM)-based spectral converter is proposed and extensively investigated to realize dynamically reconfigurable and high transparent spectral conversion. As another important innovation point of the paper, to optimize the converter performance, the optimum operation conditions of the proposed converter are deduced, statistically simulated, and experimentally verified. The optimum conditions supported-converter performances are verified by detail numerical simulations and experiments in intensity-modulation and direct-detection-based network in terms of frequency detuning range-dependent conversion efficiency, strict operation transparency for user signal characteristics, impact of parasitic components on the conversion performance, as well as the converted component waveform are almost nondistortion. It is also found that the converter has the high robustness to the input signal power, optical signal-to-noise ratio variations, extinction ratio, and driving signal frequency.

  12. Large-Deformation Curling Actuators Based on Carbon Nanotube Composite: Advanced-Structure Design and Biomimetic Application.

    Science.gov (United States)

    Chen, Luzhuo; Weng, Mingcen; Zhou, Zhiwei; Zhou, Yi; Zhang, Lingling; Li, Jiaxin; Huang, Zhigao; Zhang, Wei; Liu, Changhong; Fan, Shoushan

    2015-12-22

    In recent years, electroactive polymers have been developed as actuator materials. As an important branch of electroactive polymers, electrothermal actuators (ETAs) demonstrate potential applications in the fields of artificial muscles, biomimetic devices, robotics, and so on. Large-shape deformation, low-voltage-driven actuation, and ultrafast fabrication are critical to the development of ETA. However, a simultaneous optimization of all of these advantages has not been realized yet. Practical biomimetic applications are also rare. In this work, we introduce an ultrafast approach to fabricate a curling actuator based on a newly designed carbon nanotube and polymer composite, which completely realizes all of the above required advantages. The actuator shows an ultralarge curling actuation with a curvature greater than 1.0 cm(-1) and bending angle larger than 360°, even curling into a tubular structure. The driving voltage is down to a low voltage of 5 V. The remarkable actuation is attributed not only to the mismatch in the coefficients of thermal expansion but also to the mechanical property changes of materials during temperature change. We also construct an S-shape actuator to show the possibility of building advanced-structure actuators. A weightlifting walking robot is further designed that exhibits a fast-moving motion while lifting a sample heavier than itself, demonstrating promising biomimetic applications.

  13. Space-Based Reconfigurable Software Defined Radio Test Bed Aboard International Space Station

    Science.gov (United States)

    Reinhart, Richard C.; Lux, James P.

    2014-01-01

    The National Aeronautical and Space Administration (NASA) recently launched a new software defined radio research test bed to the International Space Station. The test bed, sponsored by the Space Communications and Navigation (SCaN) Office within NASA is referred to as the SCaN Testbed. The SCaN Testbed is a highly capable communications system, composed of three software defined radios, integrated into a flight system, and mounted to the truss of the International Space Station. Software defined radios offer the future promise of in-flight reconfigurability, autonomy, and eventually cognitive operation. The adoption of software defined radios offers space missions a new way to develop and operate space transceivers for communications and navigation. Reconfigurable or software defined radios with communications and navigation functions implemented in software or VHDL (Very High Speed Hardware Description Language) provide the capability to change the functionality of the radio during development or after launch. The ability to change the operating characteristics of a radio through software once deployed to space offers the flexibility to adapt to new science opportunities, recover from anomalies within the science payload or communication system, and potentially reduce development cost and risk by adapting generic space platforms to meet specific mission requirements. The software defined radios on the SCaN Testbed are each compliant to NASA's Space Telecommunications Radio System (STRS) Architecture. The STRS Architecture is an open, non-proprietary architecture that defines interfaces for the connections between radio components. It provides an operating environment to abstract the communication waveform application from the underlying platform specific hardware such as digital-to-analog converters, analog-to-digital converters, oscillators, RF attenuators, automatic gain control circuits, FPGAs, general-purpose processors, etc. and the interconnections among

  14. Reconfigurable network processing platforms

    NARCIS (Netherlands)

    Kachris, C.

    2007-01-01

    This dissertation presents our investigation on how to efficiently exploit reconfigurable hardware to design flexible, high performance, and power efficient network devices capable to adapt to varying processing requirements of network applications and traffic. The proposed reconfigurable network

  15. Reconfigurable architecture based on fiber bragg gratings for indoor networks (Arquitectura reconfigurable basada en redes de difracción de Bragg para redes convergentes indoor ópticas

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Puerto-Leguizamón

    2016-01-01

    Full Text Available This paper presents an approach for dynamic reconfiguration of wavelength channels for future indoor network architectures. The approach exploits the tunability and the rejection profile of Fiber Bragg Gratings (FBG to implement service distribution strategies that includes Unicast, Broadcast and Multicast scenarios for fixed and mobile users. Experimental demonstrations based on two implementations show results with 1% average degradation for Error Vector Magnitude (EVM values and up to 2,2 dB for 1x10-12 Bit Error Rate (BER. In particular, the proposed architectures fit for large in-building networks

  16. Unified Singularity Modeling and Reconfiguration of 3rTPS Metamorphic Parallel Mechanisms with Parallel Constraint Screws

    Directory of Open Access Journals (Sweden)

    Yufeng Zhuang

    2015-01-01

    Full Text Available This paper presents a unified singularity modeling and reconfiguration analysis of variable topologies of a class of metamorphic parallel mechanisms with parallel constraint screws. The new parallel mechanisms consist of three reconfigurable rTPS limbs that have two working phases stemming from the reconfigurable Hooke (rT joint. While one phase has full mobility, the other supplies a constraint force to the platform. Based on these, the platform constraint screw systems show that the new metamorphic parallel mechanisms have four topologies by altering the limb phases with mobility change among 1R2T (one rotation with two translations, 2R2T, and 3R2T and mobility 6. Geometric conditions of the mechanism design are investigated with some special topologies illustrated considering the limb arrangement. Following this and the actuation scheme analysis, a unified Jacobian matrix is formed using screw theory to include the change between geometric constraints and actuation constraints in the topology reconfiguration. Various singular configurations are identified by analyzing screw dependency in the Jacobian matrix. The work in this paper provides basis for singularity-free workspace analysis and optimal design of the class of metamorphic parallel mechanisms with parallel constraint screws which shows simple geometric constraints with potential simple kinematics and dynamics properties.

  17. Functional materials based on carbon nanotubes: Carbon nanotube actuators and noncovalent carbon nanotube modification

    Science.gov (United States)

    Fifield, Leonard S.

    Carbon nanotubes have attractive inherent properties that encourage the development of new functional materials and devices based on them. The use of single wall carbon nanotubes as electromechanical actuators takes advantage of the high mechanical strength, surface area and electrical conductivity intrinsic to these molecules. The work presented here investigates the mechanisms that have been discovered for actuation of carbon nanotube paper: electrostatic, quantum chemical charge injection, pneumatic and viscoelastic. A home-built apparatus for the measurement of actuation strain is developed and utilized in the investigation. An optical fiber switch, the first demonstrated macro-scale device based on the actuation of carbon nanotubes, is described and its performance evaluated. Also presented here is a new general process designed to modify the surface of carbon nanotubes in a non-covalent, non-destructive way. This method can be used to impart new functionalities to carbon nanotube samples for a variety of applications including sensing, solar energy conversion and chemical separation. The process described involves the achievement of large degrees of graphitic surface coverage with polycyclic aromatic hydrocarbons through the use of supercritical fluids. These molecules are bifunctional agents that anchor a desired chemical group to the aromatic surface of the carbon nanotubes without adversely disrupting the conjugated backbone that gives rise the attractive electronic and physical properties of the nanotubes. Both the nanotube functionalization work and the actuator work presented here emphasize how an understanding and control of nanoscale structure and phenomena can be of vital importance in achieving desired performance for active materials. Opportunities for new devices with improved function over current state-of-the-art can be envisioned and anticipated based on this understanding and control.

  18. Recession in a linear stepper motor based on piezoelectric actuator and electrorheological clampers

    International Nuclear Information System (INIS)

    Li, Cuihong; Meng, Yonggang; Tian, Yu

    2012-01-01

    A linear inchworm-type stepper motor based on piezoelectric actuator and comb shape electrorheological (ER) clampers was developed and tested. A recession phenomenon in the movement of the motor was found and was significantly affected by the driving voltage of the piezoelectric actuator and ER fluids. A dynamic model to analyze the mechanism of the recession was established. The force ratio of the viscoelastic clamping force (applied high electric field) to the viscous damping force (zero field) of ER fluids is the critical factor which determines the recession. The ratio is also affected by the extension or contraction rate of the actuator during movement, which is affected by the charging and discharging processes. With a relatively large distance between the clamper electrodes and a small displacement activated by the extension of the piezoelectric actuator, the instantaneous shear rate might not be sufficiently high, preventing ER fluids from attaining a shear-thickened and high-strength state. The ratio of yield strength to the viscous strength of ER fluids during movement should be as large as possible to reduce the recession displacement. (paper)

  19. New Design of a Soft Robotics Wearable Elbow Exoskeleton Based on Shape Memory Alloy Wire Actuators

    Science.gov (United States)

    Cano, Enrique; Moreno, Luis; Blanco, Dolores

    2017-01-01

    The elbow joint is a complex articulation composed of the humeroulnar and humeroradial joints (for flexion-extension movement) and the proximal radioulnar articulation (for pronation-supination movement). During the flexion-extension movement of the elbow joint, the rotation center changes and this articulation cannot be truly represented as a simple hinge joint. The main goal of this project is to design and assemble a medical rehabilitation exoskeleton for the elbow with one degree of freedom for flexion-extension, using the rotation center for proper patient elbow joint articulation. Compared with the current solutions, which align the exoskeleton axis with the elbow axis, this offers an ergonomic physical human-robot interface with a comfortable interaction. The exoskeleton is actuated with shape memory alloy wire-based actuators having minimum rigid parts, for guiding the actuators. Thanks to this unusual actuation system, the proposed exoskeleton is lightweight and has low noise in operation with a simple design 3D-printed structure. Using this exoskeleton, these advantages will improve the medical rehabilitation process of patients that suffered stroke and will influence how their lifestyle will change to recover from these diseases and improve their ability with activities of daily living, thanks to brain plasticity. The exoskeleton can also be used to evaluate the real status of a patient, with stroke and even spinal cord injury, thanks to an elbow movement analysis. PMID:29104424

  20. Centrifugal forming and mechanical properties of silicone-based elastomers for soft robotic actuators

    Science.gov (United States)

    Kulkarni, Parth

    This thesis describes the centrifugal forming and resulting mechanical properties of silicone-based elastomers for the manufacture of soft robotic actuators. This process is effective at removing bubbles that get entrapped within 3D-printed, enclosed molds. Conventional methods for rapid prototyping of soft robotic actuators to remove entrapped bubbles typically involve degassing under vacuum, with open-faced molds that limit the layout of formed parts to raised 2D geometries. As the functionality and complexity of soft robots increase, there is a need to mold complete 3D structures with controlled thicknesses or curvatures on multiples surfaces. In addition, characterization of the mechanical properties of common elastomers for these soft robots has lagged the development of new designs. As such, relationships between resulting material properties and processing parameters are virtually non-existent. One of the goals of this thesis is to provide guidelines and physical insights to relate the design, processing conditions, and resulting properties of soft robotic components to each other. Centrifugal forming with accelerations on the order of 100 g's is capable of forming bubble-free, true 3D components for soft robotic actuators, and resulting demonstrations in this work include an aquatic locomotor, soft gripper, and an actuator that straightens when pressurized. Finally, this work shows that the measured mechanical properties of 3D geometries fabricated within enclosed molds through centrifugal forming possess comparable mechanical properties to vacuumed materials formed from open-faced molds with raised 2D features.

  1. Enhanced Design of a Soft Thin-Film Vibrotactile Actuator Based on PVC Gel

    Directory of Open Access Journals (Sweden)

    Won-Hyeong Park

    2017-09-01

    Full Text Available We fabricated a soft thin-film vibrotactile actuator, which can be easily inserted into wearable devices, based on an electroactive PVC gel. One of the most important factors in fabricating a soft and thin vibrotactile actuator is to create vibrational force strong enough to stimulate human skin in a wide frequency range. To achieve this, we investigate the working principle of the PVC gel and suggest a new structure in which most of electric energy contributes to the deformation of the PVC gel. Due to this structure, the vibrational amplitude of the proposed PVC gel actuator could considerably increase (0.816 g (g = 9.8 m/s2 at resonant frequency. The vibrotactile amplitude is proportional to the amount of input voltage. It increased from 0.05 g up to 0.416 g with increasing applied voltages from 200 V to 1 kV at 1 Hz. The experimental results show that the proposed actuator can create a variety of haptic sensations.

  2. Pulse width modulation-based temperature tracking for feedback control of a shape memory alloy actuator.

    Science.gov (United States)

    Ayvali, Elif; Desai, Jaydev P

    2014-04-01

    This work presents a temperature-feedback approach to control the radius of curvature of an arc-shaped shape memory alloy (SMA) wire. The nonlinear properties of the SMA such as phase transformation and its dependence on temperature and stress make SMA actuators difficult to control. Tracking a desired trajectory is more challenging than controlling just the position of the SMA actuator since the desired path is continuously changing. Consequently, tracking the desired strain directly or tracking the parameters such as temperature and electrical resistance that are related to strain with a model is a challenging task. Temperature-feedback is an attractive approach when direct measurement of strain is not practical. Pulse width modulation (PWM) is an effective method for SMA actuation and it can be used along with a compensator to control the temperature of the SMA. Using the constitutive model of the SMA, the desired temperature profile can be obtained for a given strain trajectory. A PWM-based nonlinear PID controller with a feed-forward heat transfer model is proposed to use temperature-feedback for tracking a desired temperature trajectory. The proposed controller is used during the heating phase of the SMA actuator. The controller proves to be effective in tracking step-wise and continuous trajectories.

  3. New Design of a Soft Robotics Wearable Elbow Exoskeleton Based on Shape Memory Alloy Wire Actuators.

    Science.gov (United States)

    Copaci, Dorin; Cano, Enrique; Moreno, Luis; Blanco, Dolores

    2017-01-01

    The elbow joint is a complex articulation composed of the humeroulnar and humeroradial joints (for flexion-extension movement) and the proximal radioulnar articulation (for pronation-supination movement). During the flexion-extension movement of the elbow joint, the rotation center changes and this articulation cannot be truly represented as a simple hinge joint. The main goal of this project is to design and assemble a medical rehabilitation exoskeleton for the elbow with one degree of freedom for flexion-extension, using the rotation center for proper patient elbow joint articulation. Compared with the current solutions, which align the exoskeleton axis with the elbow axis, this offers an ergonomic physical human-robot interface with a comfortable interaction. The exoskeleton is actuated with shape memory alloy wire-based actuators having minimum rigid parts, for guiding the actuators. Thanks to this unusual actuation system, the proposed exoskeleton is lightweight and has low noise in operation with a simple design 3D-printed structure. Using this exoskeleton, these advantages will improve the medical rehabilitation process of patients that suffered stroke and will influence how their lifestyle will change to recover from these diseases and improve their ability with activities of daily living, thanks to brain plasticity. The exoskeleton can also be used to evaluate the real status of a patient, with stroke and even spinal cord injury, thanks to an elbow movement analysis.

  4. New Design of a Soft Robotics Wearable Elbow Exoskeleton Based on Shape Memory Alloy Wire Actuators

    Directory of Open Access Journals (Sweden)

    Dorin Copaci

    2017-01-01

    Full Text Available The elbow joint is a complex articulation composed of the humeroulnar and humeroradial joints (for flexion-extension movement and the proximal radioulnar articulation (for pronation-supination movement. During the flexion-extension movement of the elbow joint, the rotation center changes and this articulation cannot be truly represented as a simple hinge joint. The main goal of this project is to design and assemble a medical rehabilitation exoskeleton for the elbow with one degree of freedom for flexion-extension, using the rotation center for proper patient elbow joint articulation. Compared with the current solutions, which align the exoskeleton axis with the elbow axis, this offers an ergonomic physical human-robot interface with a comfortable interaction. The exoskeleton is actuated with shape memory alloy wire-based actuators having minimum rigid parts, for guiding the actuators. Thanks to this unusual actuation system, the proposed exoskeleton is lightweight and has low noise in operation with a simple design 3D-printed structure. Using this exoskeleton, these advantages will improve the medical rehabilitation process of patients that suffered stroke and will influence how their lifestyle will change to recover from these diseases and improve their ability with activities of daily living, thanks to brain plasticity. The exoskeleton can also be used to evaluate the real status of a patient, with stroke and even spinal cord injury, thanks to an elbow movement analysis.

  5. The effect of carbon nanofillers on the performance of electromechanical polyaniline-based composite actuators

    International Nuclear Information System (INIS)

    García-Gallegos, J C; Martín-Gullón, I; Conesa, J A; Vega-Cantú, Y I; Rodríguez-Macías, F J

    2016-01-01

    Different types of crystalline carbon nanomaterials were used to reinforce polyaniline for use in electromechanical bilayer bending actuators. The objective is to analyze how the different graphitic structures of the nanocarbons affect and improve the in situ polymerized polyaniline composites and their subsequent actuator behavior. The nanocarbons investigated were multiwalled carbon nanotubes, nitrogen-doped carbon nanotubes, helical-ribbon carbon nanofibers and graphene oxide, each one presenting different shape and structural characteristics. Films of nanocarbon-PAni composite were tested in a liquid electrolyte cell system. Experimental design was used to select the type of nanocarbon filler and composite loadings, and yielded a good balance of electromechanical properties. Raman spectroscopy suggests good interaction between PAni and the nanocarbon fillers. Electron microscopy showed that graphene oxide dispersed the best, followed by multiwall carbon nanotubes, while nitrogen-doped nanotube composites showed dispersion problems and thus poor performance. Multiwall carbon nanotube composite actuators showed the best performance based on the combination of bending angle, bending velocity and maximum working cycles, while graphene oxide attained similarly good performance due to its best dispersion. This parallel testing of a broad set of nanocarbon fillers on PAni-composite actuators is unprecedented to the best of our knowledge and shows that the type and properties of the carbon nanomaterial are critical to the performance of electromechanical devices with other conditions remaining equal. (paper)

  6. A Mobile Self-Reconfigurable Microrobot with Power and Communication Relays

    Directory of Open Access Journals (Sweden)

    Dawei Zhang

    2010-12-01

    Full Text Available A modular mobile self-reconfigurable microrobot is developed to enlarge the whole surveillance range of mobile microrobot. The microrobot is designed as differential driven vehicle equipped with a passive universal connector with autonomic engagement/disengagement function, and actuated by MEMS-based electromagnetic micromotors. To realize that the microrobot is autonomous, its electrical system is designed in modularity and integrated. A simple autonomous docking approach based on infrared sensors is presented. Experimental results verify high efficiency and reliability of the proposed docking method, and demonstrate the improved ability of performing large-range vision-based surveillance by power and communication relays.

  7. A Mobile Self-reconfigurable Microrobot with Power and Communication Relays

    Directory of Open Access Journals (Sweden)

    Dawei Zhang

    2011-01-01

    Full Text Available A modular mobile self-reconfigurable microrobot is developed to enlarge the whole surveillance range of mobile microrobot. The microrobot is designed as differential driven vehicle equipped with a passive universal connector with autonomic engagement/disengagement function, and actuated by MEMS-based electromagnetic micromotors. To realize that the microrobot is autonomous, its electrical system is designed in modularity and integrated. A simple autonomous docking approach based on infrared sensors is presented. Experimental results verify high efficiency and reliability of the proposed docking method, and demonstrate the improved ability of performing large-range vision-based surveillance by power and communication relays.

  8. Smart reconfigurable parabolic space antenna for variable electromagnetic patterns

    Science.gov (United States)

    Kalra, Sahil; Datta, Rituparna; Munjal, B. S.; Bhattacharya, Bishakh

    2018-02-01

    An application of reconfigurable parabolic space antenna for satellite is discussed in this paper. The present study focuses on shape morphing of flexible parabolic antenna actuated with Shape Memory Alloy (SMA) wires. The antenna is able to transmit the signals to the desired footprint on earth with a desired gain value. SMA wire based actuation with a locking device is developed for a precise control of Antenna shape. The locking device is efficient to hold the structure in deformed configuration during power cutoff from the system. The maximum controllable deflection at any point using such actuation system is about 25mm with a precision of ±100 m. In order to control the shape of the antenna in a closed feedback loop, a Proportional, Integral and Derivative (PID) based controller is developed using LabVIEW (NI) and experiments are performed. Numerical modeling and analysis of the structure is carried out using finite element software ABAQUS. For data reduction and fast computation, stiffness matrix generated by ABAQUS is condensed by Guyan Reduction technique and shape optimization is performed using Non-dominated Sorting Genetic Algorithm (NSGA-II). The matching in comparative study between numerical and experimental set-up shows efficacy of our method. Thereafter, Electro-Magnetic (EM) simulations of the deformed shape is carried out using electromagnetic field simulation, High Frequency Structure Simulator (HFSS). The proposed design is envisaged to be very effective for multipurpose application of satellite system in the future missions of Indian Space Research Organization (ISRO).

  9. Thermal Actuation Based 3-DoF Non-Resonant Microgyroscope Using MetalMUMPs

    Directory of Open Access Journals (Sweden)

    Muhammad Masood ul Hassan

    2009-04-01

    Full Text Available High force, large displacement and low voltage consumption are a primary concern for microgyroscopes. The chevron-shaped thermal actuators are unique in terms of high force generation combined with the large displacements at a low operating voltage in comparison with traditional electrostatic actuators. A Nickel based 3-DoF micromachined gyroscope comprising 2-DoF drive mode and 1-DoF sense mode oscillator utilizing the chevron-shaped thermal actuators is presented here. Analytical derivations and finite element simulations are carried out to predict the performance of the proposed device using the thermo-physical properties of electroplated nickel. The device sensitivity is improved by utilizing the dynamical amplification of the oscillation in 2-DoF drive mode using an active-passive mass configuration. A comprehensive theoretical description, dynamics and mechanical design considerations of the proposed gyroscopes model are discussed in detail. Parametric optimization of gyroscope, its prototype modeling and fabrication using MetalMUMPs has also been investigated. Dynamic transient simulation results predicted that the sense mass of the proposed device achieved a drive displacement of 4.1µm when a sinusoidal voltage of 0.5V is applied at 1.77 kHz exhibiting a mechanical sensitivity of 1.7μm /o/s in vacuum. The wide bandwidth frequency response of the 2-DoF drive mode oscillator consists of two resonant peaks and a flat region of 2.11 kHz between the peaks defining the operational frequency region. The sense mode resonant frequency can lie anywhere within this region and therefore the amplitude of the response is insensitive to structural parameter variations, enhancing device robustness against such variations. The proposed device has a size of 2.2 x 2.6 mm2, almost one third in comparison with existing M-DoF vibratory gyroscope with an estimated power consumption of 0.26 Watts. These predicted results illustrate that the chevron

  10. Optimization of Actuating Origami Networks

    Science.gov (United States)

    Buskohl, Philip; Fuchi, Kazuko; Bazzan, Giorgio; Joo, James; Gregory, Reich; Vaia, Richard

    2015-03-01

    Origami structures morph between 2D and 3D conformations along predetermined fold lines that efficiently program the form, function and mobility of the structure. By leveraging design concepts from action origami, a subset of origami art focused on kinematic mechanisms, reversible folding patterns for applications such as solar array packaging, tunable antennae, and deployable sensing platforms may be designed. However, the enormity of the design space and the need to identify the requisite actuation forces within the structure places a severe limitation on design strategies based on intuition and geometry alone. The present work proposes a topology optimization method, using truss and frame element analysis, to distribute foldline mechanical properties within a reference crease pattern. Known actuating patterns are placed within a reference grid and the optimizer adjusts the fold stiffness of the network to optimally connect them. Design objectives may include a target motion, stress level, or mechanical energy distribution. Results include the validation of known action origami structures and their optimal connectivity within a larger network. This design suite offers an important step toward systematic incorporation of origami design concepts into new, novel and reconfigurable engineering devices. This research is supported under the Air Force Office of Scientific Research (AFOSR) funding, LRIR 13RQ02COR.

  11. Air Ambient-Operated pNIPAM-Based Flexible Actuators Stimulated by Human Body Temperature and Sunlight.

    Science.gov (United States)

    Yamamoto, Yuki; Kanao, Kenichiro; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

    2015-05-27

    Harnessing a natural power source such as the human body temperature or sunlight should realize ultimate low-power devices. In particular, macroscale and flexible actuators that do not require an artificial power source have tremendous potential. Here we propose and demonstrate electrically powerless polymer-based actuators operated at ambient conditions using a packaging technique in which the stimulating power source is produced by heat from the human body or sunlight. The actuating angle, force, and reliability are discussed as functions of temperature and exposure to sunlight. Furthermore, a wearable device platform and a smart curtain actuated by the temperature of human skin and sunlight, respectively, are demonstrated as the first proof-of-concepts. These nature-powered actuators should realize a new class of ultimate low-power devices.

  12. Optimal reliability design for over-actuated systems based on the MIT rule: Application to an octocopter helicopter testbed

    International Nuclear Information System (INIS)

    Chamseddine, Abbas; Theilliol, Didier; Sadeghzadeh, Iman; Zhang, Youmin; Weber, Philippe

    2014-01-01

    This paper addresses the problem of optimal reliability in over-actuated systems. Overloading an actuator decreases its overall lifetime and reduces its average performance over a long time. Therefore, performance and reliability are two conflicting requirements. While appropriate reliability is related to average loads, good performance is related to fast response and sufficient loads generated by actuators. Actuator redundancy allows us to address both performance and reliability at the same time by properly allocating desired loads among redundant actuators. The main contribution of this paper is the on-line optimization of the overall plant reliability according to performance objective using an MIT (Massachusetts Institute of Technology) rule-based method. The effectiveness of the proposed method is illustrated through an experimental application to an octocopter helicopter testbed

  13. Implementing Workflow Reconfiguration in WS-BPEL

    DEFF Research Database (Denmark)

    Mazzara, Manuel; Dragoni, Nicola; Zhou, Mu

    2012-01-01

    This paper investigates the problem of dynamic reconfiguration by means of a workflow-based case study used for discussion. We state the requirements on a system implementing the workflow and its reconfiguration, and we describe the system’s design in BPMN. WS-BPEL, a language that would not natu......This paper investigates the problem of dynamic reconfiguration by means of a workflow-based case study used for discussion. We state the requirements on a system implementing the workflow and its reconfiguration, and we describe the system’s design in BPMN. WS-BPEL, a language that would...... not naturally support dynamic change, is used as a target for implementation. The WS-BPEL recovery framework is here exploited to implement the reconfiguration using principles derived from previous research in process algebra and two mappings from BPMN to WS-BPEL are presented, one automatic and only mostly...

  14. A Survey on FPGA-Based Sensor Systems: Towards Intelligent and Reconfigurable Low-Power Sensors for Computer Vision, Control and Signal Processing

    Directory of Open Access Journals (Sweden)

    Gabriel J. García

    2014-03-01

    Full Text Available The current trend in the evolution of sensor systems seeks ways to provide more accuracy and resolution, while at the same time decreasing the size and power consumption. The use of Field Programmable Gate Arrays (FPGAs provides specific reprogrammable hardware technology that can be properly exploited to obtain a reconfigurable sensor system. This adaptation capability enables the implementation of complex applications using the partial reconfigurability at a very low-power consumption. For highly demanding tasks FPGAs have been favored due to the high efficiency provided by their architectural flexibility (parallelism, on-chip memory, etc., reconfigurability and superb performance in the development of algorithms. FPGAs have improved the performance of sensor systems and have triggered a clear increase in their use in new fields of application. A new generation of smarter, reconfigurable and lower power consumption sensors is being developed in Spain based on FPGAs. In this paper, a review of these developments is presented, describing as well the FPGA technologies employed by the different research groups and providing an overview of future research within this field.

  15. A survey on FPGA-based sensor systems: towards intelligent and reconfigurable low-power sensors for computer vision, control and signal processing.

    Science.gov (United States)

    García, Gabriel J; Jara, Carlos A; Pomares, Jorge; Alabdo, Aiman; Poggi, Lucas M; Torres, Fernando

    2014-03-31

    The current trend in the evolution of sensor systems seeks ways to provide more accuracy and resolution, while at the same time decreasing the size and power consumption. The use of Field Programmable Gate Arrays (FPGAs) provides specific reprogrammable hardware technology that can be properly exploited to obtain a reconfigurable sensor system. This adaptation capability enables the implementation of complex applications using the partial reconfigurability at a very low-power consumption. For highly demanding tasks FPGAs have been favored due to the high efficiency provided by their architectural flexibility (parallelism, on-chip memory, etc.), reconfigurability and superb performance in the development of algorithms. FPGAs have improved the performance of sensor systems and have triggered a clear increase in their use in new fields of application. A new generation of smarter, reconfigurable and lower power consumption sensors is being developed in Spain based on FPGAs. In this paper, a review of these developments is presented, describing as well the FPGA technologies employed by the different research groups and providing an overview of future research within this field.

  16. Synthesis of new solid polymer electrolyte and actuator based on PEDOT/NBR/ionic liquid

    Science.gov (United States)

    Cho, M. S.; Seo, H. J.; Nam, J. D.; Choi, H. R.; Koo, J. C.; Lee, Y.

    2006-03-01

    The conducting polymer actuator was presented. The solid polymer electrolyte based on nitrile rubber (NBR) activated with different ionic liquids was prepared. The three different grades of NBR films were synthesized by emulsion polymerization with different amount of acrylonitrile, 23, 35, and 40 mol. %, respectively. The effect of acrylonitrile content on the ionic conductivity and dielectric constant of solid polymer electrolytes was characterized. A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the NBR layer by using a chemical oxidation polymerization technique, and room temperature ionic liquids (RTIL) based on imidazolium salts, e.g. 1-butyl-3-methyl imidazolium X [where X= BF 4 -, PF 6 -, (CF 3SO II) IIN -], were absorbed into the composite film. The effects of the anion size of the ionic liquids on the displacement of the actuator were examined. The displacement increased with increasing the anion-size of the ionic liquids.

  17. Data-based fault-tolerant control for affine nonlinear systems with actuator faults.

    Science.gov (United States)

    Xie, Chun-Hua; Yang, Guang-Hong

    2016-09-01

    This paper investigates the fault-tolerant control (FTC) problem for unknown nonlinear systems with actuator faults including stuck, outage, bias and loss of effectiveness. The upper bounds of stuck faults, bias faults and loss of effectiveness faults are unknown. A new data-based FTC scheme is proposed. It consists of the online estimations of the bounds and a state-dependent function. The estimations are adjusted online to compensate automatically the actuator faults. The state-dependent function solved by using real system data helps to stabilize the system. Furthermore, all signals in the resulting closed-loop system are uniformly bounded and the states converge asymptotically to zero. Compared with the existing results, the proposed approach is data-based. Finally, two simulation examples are provided to show the effectiveness of the proposed approach. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

    Science.gov (United States)

    Keum, Jung-Hoon; Ra, Sung-Woong

    2009-12-01

    Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

  19. PZT crack detection in suspension-based dual stage actuator [for HDDs

    CERN Document Server

    Yung Ping Yeh; Ku, C

    2000-01-01

    An impedance method is proposed to detect cracks of PZT bars in suspension based dual stage-actuators. The frequency response amplitude of impedance at the resonance of 1.95 MHz, the PZT bar width extension mode, was very sensitive to the cracks in PZT material. As cracks in the PZT bars propagated from invisible micro cracks to visible macro cracks, the impedance gain at 1.95 MHz dropped suddenly. (3 refs).

  20. Towards a digital sound reconstruction MEMS device: Characterization of a single PZT based piezoelectric actuator

    KAUST Repository

    Carreno, Armando Arpys Arevalo; Conchouso Gonzalez, David; Castro, David; Jaber, Nizar; Younis, Mohammad I.; Foulds, Ian G.

    2015-01-01

    of acoustic actuators. These actuators consist of a flexible membrane fabricated using polyimide, which is actuated using a Lead-Zirconate-Titanate (PZT) piezoelectric ceramic layer working in the d31 actuation mode. The dimensions of the membrane are of 1mm

  1. Reconfigurable Braille display with phase change locking

    Science.gov (United States)

    Soule, Cody W.; Lazarus, Nathan

    2016-07-01

    Automatically updated signs and displays for sighted people are common in today’s world. However, there is no cheap, low power equivalent available for the blind. This work demonstrates a reconfigurable Braille cell using the solid-to-liquid phase change of a low melting point alloy as a zero holding power locking mechanism. The device is actuated with the alloy in the liquid state, and is then allowed to solidify to lock the Braille dot in the actuated position. A low-cost manufacturing process is developed that includes molding of a rigid silicone to create pneumatic channels, and bonding of a thin membrane of a softer silicone on the surface for actuation. A plug of Field’s metal (melting point 62 °C) is placed in the pneumatic channels below each Braille dot to create the final device. The device is well suited for low duty cycle operation in applications such as signs, and is able to maintain its state indefinitely without additional power input. The display requires a pneumatic pressure of only 24 kPa for actuation, and reconfiguration has been demonstrated in less than a minute and a half.

  2. A 10 Gb/s passive-components-based WDM-TDM reconfigurable optical access network architecture

    NARCIS (Netherlands)

    Tran, N.C.; Jung, H.D.; Okonkwo, C.M.; Tangdiongga, E.; Koonen, A.M.J.

    2011-01-01

    We propose a cost-effective, reconfigurable optical access network by employing passive components in the remote node and dual conventional optical transceivers in ONUs. The architecture is demonstrated with bidirectional transmission at 10 Gb/s.

  3. Two Reconfigurable Flight-Control Design Methods: Robust Servomechanism and Control Allocation

    Science.gov (United States)

    Burken, John J.; Lu, Ping; Wu, Zheng-Lu; Bahm, Cathy

    2001-01-01

    Two methods for control system reconfiguration have been investigated. The first method is a robust servomechanism control approach (optimal tracking problem) that is a generalization of the classical proportional-plus-integral control to multiple input-multiple output systems. The second method is a control-allocation approach based on a quadratic programming formulation. A globally convergent fixed-point iteration algorithm has been developed to make onboard implementation of this method feasible. These methods have been applied to reconfigurable entry flight control design for the X-33 vehicle. Examples presented demonstrate simultaneous tracking of angle-of-attack and roll angle commands during failures of the fight body flap actuator. Although simulations demonstrate success of the first method in most cases, the control-allocation method appears to provide uniformly better performance in all cases.

  4. Reconfigurable Flight Control Designs With Application to the X-33 Vehicle

    Science.gov (United States)

    Burken, John J.; Lu, Ping; Wu, Zhenglu

    1999-01-01

    Two methods for control system reconfiguration have been investigated. The first method is a robust servomechanism control approach (optimal tracking problem) that is a generalization of the classical proportional-plus-integral control to multiple input-multiple output systems. The second method is a control-allocation approach based on a quadratic programming formulation. A globally convergent fixed-point iteration algorithm has been developed to make onboard implementation of this method feasible. These methods have been applied to reconfigurable entry flight control design for the X-33 vehicle. Examples presented demonstrate simultaneous tracking of angle-of-attack and roll angle commands during failures of the right body flap actuator. Although simulations demonstrate success of the first method in most cases, the control-allocation method appears to provide uniformly better performance in all cases.

  5. Improved actuation strain of PDMS-based DEA materials chemically modified with softening agents

    Science.gov (United States)

    Biedermann, Miriam; Blümke, Martin; Wegener, Michael; Krüger, Hartmut

    2015-04-01

    Dielectric elastomer actuators (DEAs) are smart materials that gained much in interest particularly in recent years. One active field of research is the improvement of their properties by modification of their structural framework. The object of this work is to improve the actuation properties of polydimethylsiloxane (PDMS)-based DEAs by covalent incorporation of mono-vinyl-terminated low-molecular PDMS chains into the PDMS network. These low-molecular units act as a kind of softener within the PDMS network. The loose chain ends interfere with the network formation and lower the network's density. PDMS films with up to 50wt% of low-molecular PDMS additives were manufactured and the chemical, mechanical, electrical, and electromechanical properties of these novel materials were investigated.

  6. Stabilisation of a three-dimensional boundary layer by base-flow manipulation using plasma actuators

    International Nuclear Information System (INIS)

    Dörr, P C; Kloker, M J

    2015-01-01

    The applicability of dielectric barrier discharge plasma actuators for controlling the crossflow-vortex-induced laminar breakdown in a three-dimensional swept-wing-type boundary-layer flow is investigated using direct numerical simulation. Similar to the classical application of suction at the wall the aim is to modify the quasi two-dimensional base flow and to weaken primary crossflow (CF) instability, mainly due to a reduction of the basic CF. Not only localised volumetric forcing by plasma actuators but also CF counter-blowing and spots with a moving wall are investigated to identify effective fundamental mechanisms. It is found that counter blowing always results in partial blockage of the flow and eventually increased CF velocity, whereas moving-wall spots can slightly reduce the CF and the amplitude of crossflow vortices. Using discrete volumetric forcing a significant attenuation even of finite-amplitude crossflow vortices and thus a distinct transition delay is achieved. (paper)

  7. A new amplifier for improving piezoelectric actuator linearity based on current switching in precision positioning

    International Nuclear Information System (INIS)

    Ru, Changhai; Chen, Liguo; Shao, Bing; Rong, Weibin; Sun, Lining

    2008-01-01

    Piezoelectric actuators have traditionally been driven by voltage amplifiers. When driven at large voltages these actuators exhibit a significant amount of distortion, known as hysteresis, which may reduce the stability robustness of the system in feedback control applications. Piezoelectric transducers are known to exhibit less hysteresis when driven with current or charge rather than voltage. Despite this advantage, such methods have found little practical application due to the poor low frequency response of present current and charge driver designs. In this paper, a new piezoelectric amplifier based on current switching is presented which can reduce hysteresis. Special circuits and a hybrid control algorithm realize quick and precise positioning. Experimental results demonstrate that the amplifier can be used for dynamic and static applications and low frequency bandwidths can also be achieved

  8. A biomimetic jellyfish robot based on ionic polymer metal composite actuators

    International Nuclear Information System (INIS)

    Yeom, Sung-Weon; Oh, Il-Kwon

    2009-01-01

    A biomimetic jellyfish robot based on ionic polymer metal composite actuators was fabricated and activated to mimic real locomotive behavior with pulse and recovery processes. To imitate the curved shape of the jellyfish, a thermal treatment was applied to obtain a permanent initial deformation of a hemispherical form. The bio-inspired input signal was generated for mimicking real locomotion of the jellyfish. The vertical floating displacement and the thrust force of the biomimetic jellyfish robot under various input signals were measured and compared. The present results show that the bio-inspired electrical input signal with pulse-recovery process generates much higher floating velocity of the biomimetic jellyfish robot in comparison with pure sinusoidal excitations. The curved shape of the IPMC actuator through thermal treatments can be successfully applied to mimic the real biomimetic robots with smooth curves

  9. Dynamic behaviour of ISFET-based Sensor-Actuator systems

    NARCIS (Netherlands)

    Olthuis, Wouter; Luo, J.; Luo, J.; van der Schoot, B.H.; van der Schoot, B.H.; Bomer, Johan G.; Bergveld, Piet

    1990-01-01

    Rapid acid-base titrations can be performed at the surface of a noble-metal electrode with coulometrically generated ions. An ISFET is used as an indicator electrode to detect the equivalence point in the resulting titration curve. The time needed to reach the equivalence point is typically 0.5 to

  10. Tendon-Based Stiffening for a Pneumatically Actuated Soft Manipulator

    OpenAIRE

    Shiva, A.; Stilli, A.; Noh, Y.; Faragasso, A.; Falco, I. D.; Gerboni, G.; Cianchetti, M.; Menciassi, A.; Althoefer, K.; Wurdemann, H. A.

    2016-01-01

    There is an emerging trend toward soft robotics due to its extended manipulation capabilities compared to traditionally rigid robot links, showing promise for an extended applicability to new areas. However, as a result of the inherent property of soft robotics being less rigid, the ability to control/obtain higher overall stiffness when required is yet to be further explored. In this letter, an innovative design is introduced which allows varying the stiffness of a continuum silicon-based ma...

  11. Reconfigurable Integrated Optoelectronics

    Directory of Open Access Journals (Sweden)

    Richard Soref

    2011-01-01

    Full Text Available Integrated optics today is based upon chips of Si and InP. The future of this chip industry is probably contained in the thrust towards optoelectronic integrated circuits (OEICs and photonic integrated circuits (PICs manufactured in a high-volume foundry. We believe that reconfigurable OEICs and PICs, known as ROEICs and RPICs, constitute the ultimate embodiment of integrated photonics. This paper shows that any ROEIC-on-a-chip can be decomposed into photonic modules, some of them fixed and some of them changeable in function. Reconfiguration is provided by electrical control signals to the electro-optical building blocks. We illustrate these modules in detail and discuss 3D ROEIC chips for the highest-performance signal processing. We present examples of our module theory for RPIC optical lattice filters already constructed, and we propose new ROEICs for directed optical logic, large-scale matrix switching, and 2D beamsteering of a phased-array microwave antenna. In general, large-scale-integrated ROEICs will enable significant applications in computing, quantum computing, communications, learning, imaging, telepresence, sensing, RF/microwave photonics, information storage, cryptography, and data mining.

  12. Introduction to Reconfigurable Supercomputing

    CERN Document Server

    Lanzagorta, Marco; Rosenberg, Robert

    2010-01-01

    This book covers technologies, applications, tools, languages, procedures, advantages, and disadvantages of reconfigurable supercomputing using Field Programmable Gate Arrays (FPGAs). The target audience is the community of users of High Performance Computers (HPe who may benefit from porting their applications into a reconfigurable environment. As such, this book is intended to guide the HPC user through the many algorithmic considerations, hardware alternatives, usability issues, programming languages, and design tools that need to be understood before embarking on the creation of reconfigur

  13. Component based modelling of piezoelectric ultrasonic actuators for machining applications

    International Nuclear Information System (INIS)

    Saleem, A; Ahmed, N; Salah, M; Silberschmidt, V V

    2013-01-01

    Ultrasonically Assisted Machining (UAM) is an emerging technology that has been utilized to improve the surface finishing in machining processes such as turning, milling, and drilling. In this context, piezoelectric ultrasonic transducers are being used to vibrate the cutting tip while machining at predetermined amplitude and frequency. However, modelling and simulation of these transducers is a tedious and difficult task. This is due to the inherent nonlinearities associated with smart materials. Therefore, this paper presents a component-based model of ultrasonic transducers that mimics the nonlinear behaviour of such a system. The system is decomposed into components, a mathematical model of each component is created, and the whole system model is accomplished by aggregating the basic components' model. System parameters are identified using Finite Element technique which then has been used to simulate the system in Matlab/SIMULINK. Various operation conditions are tested and performed to demonstrate the system performance

  14. Non-linear time variant model intended for polypyrrole-based actuators

    Science.gov (United States)

    Farajollahi, Meisam; Madden, John D. W.; Sassani, Farrokh

    2014-03-01

    Polypyrrole-based actuators are of interest due to their biocompatibility, low operation voltage and relatively high strain and force. Modeling and simulation are very important to predict the behaviour of each actuator. To develop an accurate model, we need to know the electro-chemo-mechanical specifications of the Polypyrrole. In this paper, the non-linear time-variant model of Polypyrrole film is derived and proposed using a combination of an RC transmission line model and a state space representation. The model incorporates the potential dependent ionic conductivity. A function of ionic conductivity of Polypyrrole vs. local charge is proposed and implemented in the non-linear model. Matching of the measured and simulated electrical response suggests that ionic conductivity of Polypyrrole decreases significantly at negative potential vs. silver/silver chloride and leads to reduced current in the cyclic voltammetry (CV) tests. The next stage is to relate the distributed charging of the polymer to actuation via the strain to charge ratio. Further work is also needed to identify ionic and electronic conductivities as well as capacitance as a function of oxidation state so that a fully predictive model can be created.

  15. Kinematics and control of redundant robotic arm based on dielectric elastomer actuators

    Science.gov (United States)

    Branz, Francesco; Antonello, Andrea; Carron, Andrea; Carli, Ruggero; Francesconi, Alessandro

    2015-04-01

    Soft robotics is a promising field and its application to space mechanisms could represent a breakthrough in space technologies by enabling new operative scenarios (e.g. soft manipulators, capture systems). Dielectric Elastomers Actuators have been under deep study for a number of years and have shown several advantages that could be of key importance for space applications. Among such advantages the most notable are high conversion efficiency, distributed actuation, self-sensing capability, multi-degree-of-freedom design, light weight and low cost. The big potentialities of double cone actuators have been proven in terms of good performances (i.e. stroke and force/torque), ease of manufacturing and durability. In this work the kinematic, dynamic and control design of a two-joint redundant robotic arm is presented. Two double cone actuators are assembled in series to form a two-link design. Each joint has two degrees of freedom (one rotational and one translational) for a total of four. The arm is designed to move in a 2-D environment (i.e. the horizontal plane) with 4 DoF, consequently having two degrees of redundancy. The redundancy is exploited in order to minimize the joint loads. The kinematic design with redundant Jacobian inversion is presented. The selected control algorithm is described along with the results of a number of dynamic simulations that have been executed for performance verification. Finally, an experimental setup is presented based on a flexible structure that counteracts gravity during testing in order to better emulate future zero-gravity applications.

  16. Microheaters based on ultrasonic actuation of piezoceramic elements

    Science.gov (United States)

    Visvanathan, Karthik; Gianchandani, Yogesh B.

    2011-08-01

    This paper describes the use of micromachined lead zirconate titanate (PZT) piezoceramic elements for heat generation by ultrasonic energy dissipated within the elements and surrounding media. Simulations based on three-dimensional finite-element models suggest that circular disk-shaped elements provide superior steady-state temperature rise for a given cross-sectional area, volume of the PZT element and drive voltage. Experimental validation is performed using PZT-5A heaters of 3.2 mm diameter and 0.191 mm thickness. Single-element heaters and dual-element stacks are evaluated. Although the steady-state temperature generated by these heaters reaches the maximum value at the frequency of maximum electromechanical conductance, the heating effectiveness is maximized at the frequency of maximum electromechanical impedance. Stacked PZT heaters provide 3.5 times the temperature rise and 3 times greater heating effectiveness than single elements. Furthermore, the heaters attain the maximum heating effectiveness when bonded to highly damping and non-conducting substrates. A maximum temperature of 120 °C is achieved at 160 mW input power. Experiments are performed using porcine tissue samples to show the feasibility of using PZT heaters in tissue cauterization. A PZT heater probe brands a porcine tissue in 2-3 s with 10 VRMS drive voltage. The interface temperature is ≈150 °C.

  17. Characterization​ and ​analysis of ​m​otion ​m​echanism​ of electroactive​ chitosan-based actuator.

    Science.gov (United States)

    Altınkaya, Emine; Seki, Yoldaş; Çetin, Levent; Gürses, Barış Oğuz; Özdemir, Okan; Sever, Kutlay; Sarıkanat, Mehmet

    2018-02-01

    In order to analyze the bending mechanism of the electroactive​ chitosan-based actuator, different amounts of poly(diallyldimethylammonium chloride) (PDAD) were incorporated in chitosan solution. The effects of PDAD concentration on electromechanical performance of chitosan actuator were investigated under various excitation voltages. With the incorporation of PDAD into chitosan solution, crosslinked chitosan film acts as an actuator showing a considerable displacement behavior. However it can be noted that higher incorporation of PDAD into chitosan solution decreased the performance of the actuators. Thermal, viscoelastic, and crystallographic properties of the chitosan films were examined by thermogravimetric analysis, dynamic mechanical analysis, and X-ray diffraction analysis, respectively. The effect of incorporation of PDAD in chitosan-based film on morphological properties of chitosan film was determined by scanning electron microscopy. It was observed that the films involving PDAD have larger pore size than the PDAD free film. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Simple Approach For Induction Motor Control Using Reconfigurable Hardware

    Directory of Open Access Journals (Sweden)

    József VÁSÁRHELYI

    2002-12-01

    Full Text Available The paper deals with rotor-field-oriented vector control structures for the induction motor drives fed by the so-called tandem frequency converter. It is composed of two different types of DC-link converters connected in parallel arrangement. The larger-power one has current-source character and is operating synchronized in time and in amplitude with the stator currents. The other one has voltage-source character and it is the actuator of the motor control system. The drive is able to run also with partial-failed tandem converter, if the control strategy corresponds to the actual operating mode. A reconfigurable hardware implemented in configurable logic cells ensures the changing of the vector-control structure. The proposed control schemes were tested by simulation based on Matlab-Simulink model.

  19. Control of supersonic axisymmetric base flows using passive splitter plates and pulsed plasma actuators

    Science.gov (United States)

    Reedy, Todd Mitchell

    influenced considerably, the area-integrated pressure was only slightly affected. Normalized RMS levels indicate that base pressure fluctuations were significantly reduced with the addition of the splitter plates. Power-spectral-density estimates revealed a spectral broadening of fluctuating energy for the 1/2 cylinder configuration and a bimodal distribution for the 1/3 and 1/4 cylinder configurations. It was concluded that the recirculation region is not the most sensitive location to apply flow control; rather, the shear layer may be a more influential site for implementing flow control methodologies. For active flow control, pulsed plasma-driven fluidic actuators were investigated. Initially, the performance of two plasma actuator designs was characterized to determine their potential as supersonic flow control devices. For the first actuator considered, the pulsed plasma jet, electro-thermal heating from an electric discharge heats and pressurizes gas in a small cavity which is exhausted through a circular orifice forming a synthetic jet. Depending on the electrical energy addition, peak jet velocities ranged between 130 to nearly 500 m/s when exhausted to quiescent, ambient conditions. The second plasma actuator investigated is the localized arc filament plasma actuator (LAFPA), which created fluidic perturbations through the rapid, local thermal heating, generated from an electric arc discharge between two electrodes within a shallow open cavity. Electrical and emission properties of the LAFPA were first documented as a function of pressure in a quiescent, no-flow environment. Rotational and vibrational temperatures from N2 spectra were obtained for select plasma conditions and ambient pressures. Results further validate that the assumption of optically thin conditions for these electric arc plasmas is not necessary valid, even at low ambient pressure. Breakdown voltage, sustained plasma voltage, power, and energy per pulse were demonstrated to decrease with

  20. Reconfigurable radio systems network architectures and standards

    CERN Document Server

    Iacobucci, Maria Stella

    2013-01-01

    This timely book provides a standards-based view of the development, evolution, techniques and potential future scenarios for the deployment of reconfigurable radio systems.  After an introduction to radiomobile and radio systems deployed in the access network, the book describes cognitive radio concepts and capabilities, which are the basis for reconfigurable radio systems.  The self-organizing network features introduced in 3GPP standards are discussed and IEEE 802.22, the first standard based on cognitive radio, is described. Then the ETSI reconfigurable radio systems functional ar

  1. Reconfigurable fault tolerant avionics system

    Science.gov (United States)

    Ibrahim, M. M.; Asami, K.; Cho, Mengu

    This paper presents the design of a reconfigurable avionics system based on modern Static Random Access Memory (SRAM)-based Field Programmable Gate Array (FPGA) to be used in future generations of nano satellites. A major concern in satellite systems and especially nano satellites is to build robust systems with low-power consumption profiles. The system is designed to be flexible by providing the capability of reconfiguring itself based on its orbital position. As Single Event Upsets (SEU) do not have the same severity and intensity in all orbital locations, having the maximum at the South Atlantic Anomaly (SAA) and the polar cusps, the system does not have to be fully protected all the time in its orbit. An acceptable level of protection against high-energy cosmic rays and charged particles roaming in space is provided within the majority of the orbit through software fault tolerance. Check pointing and roll back, besides control flow assertions, is used for that level of protection. In the minority part of the orbit where severe SEUs are expected to exist, a reconfiguration for the system FPGA is initiated where the processor systems are triplicated and protection through Triple Modular Redundancy (TMR) with feedback is provided. This technique of reconfiguring the system as per the level of the threat expected from SEU-induced faults helps in reducing the average dynamic power consumption of the system to one-third of its maximum. This technique can be viewed as a smart protection through system reconfiguration. The system is built on the commercial version of the (XC5VLX50) Xilinx Virtex5 FPGA on bulk silicon with 324 IO. Simulations of orbit SEU rates were carried out using the SPENVIS web-based software package.

  2. Program Execution on Reconfigurable Multicore Architectures

    Directory of Open Access Journals (Sweden)

    Sanjiva Prasad

    2016-06-01

    Full Text Available Based on the two observations that diverse applications perform better on different multicore architectures, and that different phases of an application may have vastly different resource requirements, Pal et al. proposed a novel reconfigurable hardware approach for executing multithreaded programs. Instead of mapping a concurrent program to a fixed architecture, the architecture adaptively reconfigures itself to meet the application's concurrency and communication requirements, yielding significant improvements in performance. Based on our earlier abstract operational framework for multicore execution with hierarchical memory structures, we describe execution of multithreaded programs on reconfigurable architectures that support a variety of clustered configurations. Such reconfiguration may not preserve the semantics of programs due to the possible introduction of race conditions arising from concurrent accesses to shared memory by threads running on the different cores. We present an intuitive partial ordering notion on the cluster configurations, and show that the semantics of multithreaded programs is always preserved for reconfigurations "upward" in that ordering, whereas semantics preservation for arbitrary reconfigurations can be guaranteed for well-synchronised programs. We further show that a simple approximate notion of efficiency of execution on the different configurations can be obtained using the notion of amortised bisimulations, and extend it to dynamic reconfiguration.

  3. Real-Time Algebraic Derivative Estimations Using a Novel Low-Cost Architecture Based on Reconfigurable Logic

    Science.gov (United States)

    Morales, Rafael; Rincón, Fernando; Gazzano, Julio Dondo; López, Juan Carlos

    2014-01-01

    Time derivative estimation of signals plays a very important role in several fields, such as signal processing and control engineering, just to name a few of them. For that purpose, a non-asymptotic algebraic procedure for the approximate estimation of the system states is used in this work. The method is based on results from differential algebra and furnishes some general formulae for the time derivatives of a measurable signal in which two algebraic derivative estimators run simultaneously, but in an overlapping fashion. The algebraic derivative algorithm presented in this paper is computed online and in real-time, offering high robustness properties with regard to corrupting noises, versatility and ease of implementation. Besides, in this work, we introduce a novel architecture to accelerate this algebraic derivative estimator using reconfigurable logic. The core of the algorithm is implemented in an FPGA, improving the speed of the system and achieving real-time performance. Finally, this work proposes a low-cost platform for the integration of hardware in the loop in MATLAB. PMID:24859033

  4. Global calibration of multi-cameras with non-overlapping fields of view based on photogrammetry and reconfigurable target

    Science.gov (United States)

    Xia, Renbo; Hu, Maobang; Zhao, Jibin; Chen, Songlin; Chen, Yueling

    2018-06-01

    Multi-camera vision systems are often needed to achieve large-scale and high-precision measurement because these systems have larger fields of view (FOV) than a single camera. Multiple cameras may have no or narrow overlapping FOVs in many applications, which pose a huge challenge to global calibration. This paper presents a global calibration method for multi-cameras without overlapping FOVs based on photogrammetry technology and a reconfigurable target. Firstly, two planar targets are fixed together and made into a long target according to the distance between the two cameras to be calibrated. The relative positions of the two planar targets can be obtained by photogrammetric methods and used as invariant constraints in global calibration. Then, the reprojection errors of target feature points in the two cameras’ coordinate systems are calculated at the same time and optimized by the Levenberg–Marquardt algorithm to find the optimal solution of the transformation matrix between the two cameras. Finally, all the camera coordinate systems are converted to the reference coordinate system in order to achieve global calibration. Experiments show that the proposed method has the advantages of high accuracy (the RMS error is 0.04 mm) and low cost and is especially suitable for on-site calibration.

  5. Dual sensing-actuation artificial muscle based on polypyrrole-carbon nanotube composite

    Science.gov (United States)

    Schumacher, J.; Otero, Toribio F.; Pascual, Victor H.

    2017-04-01

    Dual sensing artificial muscles based on conducting polymer are faradaic motors driven by electrochemical reactions, which announce the development of proprioceptive devices. The applicability of different composites has been investigated with the aim to improve the performance. Addition of carbon nanotubes may reduce irreversible reactions. We present the testing of a dual sensing artificial muscle based on a conducting polymer and carbon nanotubes composite. Large bending motions (up to 127 degrees) in aqueous solution and simultaneously sensing abilities of the operation conditions are recorded. The sensing and actuation equations are derived for incorporation into a control system.

  6. Efficient Structure-Based Models for the McKibben Contraction Pneumatic Muscle Actuator: The Full Description of the Behaviour of the Contraction PMA

    Directory of Open Access Journals (Sweden)

    Alaa Al-Ibadi

    2017-10-01

    Full Text Available To clarify the advantages of using soft robots in all aspects of life, the effective behaviour of the pneumatic muscle actuator (PMA must be known. In this work, the performances of the PMA are explained and modelled with three formulas. The first formula describes the pulling force of the actuator based on the structure parameters; furthermore, the formula presented is the generalised contraction force for wholly-pneumatic muscle actuators. The second important model is the length formula, which is modified to our previous work to fit different actuator structures. Based on these two models, the stiffness of the actuator is formulated to illustrate its variability at different air pressure amounts. In addition, these formulas will make the selection of proper actuators for any robot arm structure easier using the knowledge gained from their performance. On the other hand, the desired behaviour of this type of actuator will be predefined and controlled.

  7. Design of reconfigurable antennas using graph models

    CERN Document Server

    Costantine, Joseph; Christodoulou, Christos G; Christodoulou, Christos G

    2013-01-01

    This lecture discusses the use of graph models to represent reconfigurable antennas. The rise of antennas that adapt to their environment and change their operation based on the user's request hasn't been met with clear design guidelines. There is a need to propose some rules for the optimization of any reconfigurable antenna design and performance. Since reconfigurable antennas are seen as a collection of self-organizing parts, graph models can be introduced to relate each possible topology to a corresponding electromagnetic performance in terms of achieving a characteristic frequency of oper

  8. Rough terrain motion planning for actively reconfigurable mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Michael

    2015-02-05

    In the aftermath of the Tohoku earthquake and the nuclear meltdown at the power plant of Fukushima Daiichi in 2011, reconfigurable robots like the iRobot Packbot were deployed. Instead of humans, the robots were used to investigate contaminated areas. Other incidents are the two major earthquakes in Northern Italy in May 2012. Besides many casualties, a large number of historical buildings was severely damaged. Due to the imminent danger of collapse, it was too dangerous for rescue personnel to enter many of the buildings. Therefore, the sites were inspected by reconfigurable robots, which are able to traverse the rubble and debris of the partially destroyed buildings. This thesis develops a navigation system enabling wheeled and tracked robots to safely traverse rough terrain and challenging structures. It consists of a planning mechanism and a controller. The focus of this thesis, however, is on the contribution to motion planning. The planning scheme employs a hierarchical approach to motion planning for actively reconfigurable robots in rough environments. Using a map of the environment the algorithm estimates the traversability under the consideration of uncertainties. Based on this analysis, an initial path search determines an approximate solution with respect to the robot's operating limits.Subsequently, a detailed planning step refines the initial path where it is required. The refinement step considers the robot's actuators and stability in addition to the quantities of the first search. Determining the robot-terrain interaction is very important in rough terrain. This thesis presents two path refinement approaches: a deterministic and a randomized approach. The experimental evaluation investigates the separate components of the planning scheme, the robot-terrain interaction for instance.In simulation as well as in real world experiments the evaluation demonstrates the necessity of such a planning algorithm in rough terrain and it provides

  9. Rough terrain motion planning for actively reconfigurable mobile robots

    International Nuclear Information System (INIS)

    Brunner, Michael

    2015-01-01

    In the aftermath of the Tohoku earthquake and the nuclear meltdown at the power plant of Fukushima Daiichi in 2011, reconfigurable robots like the iRobot Packbot were deployed. Instead of humans, the robots were used to investigate contaminated areas. Other incidents are the two major earthquakes in Northern Italy in May 2012. Besides many casualties, a large number of historical buildings was severely damaged. Due to the imminent danger of collapse, it was too dangerous for rescue personnel to enter many of the buildings. Therefore, the sites were inspected by reconfigurable robots, which are able to traverse the rubble and debris of the partially destroyed buildings. This thesis develops a navigation system enabling wheeled and tracked robots to safely traverse rough terrain and challenging structures. It consists of a planning mechanism and a controller. The focus of this thesis, however, is on the contribution to motion planning. The planning scheme employs a hierarchical approach to motion planning for actively reconfigurable robots in rough environments. Using a map of the environment the algorithm estimates the traversability under the consideration of uncertainties. Based on this analysis, an initial path search determines an approximate solution with respect to the robot's operating limits.Subsequently, a detailed planning step refines the initial path where it is required. The refinement step considers the robot's actuators and stability in addition to the quantities of the first search. Determining the robot-terrain interaction is very important in rough terrain. This thesis presents two path refinement approaches: a deterministic and a randomized approach. The experimental evaluation investigates the separate components of the planning scheme, the robot-terrain interaction for instance.In simulation as well as in real world experiments the evaluation demonstrates the necessity of such a planning algorithm in rough terrain and it provides

  10. Dissipativity-Based Reliable Control for Fuzzy Markov Jump Systems With Actuator Faults.

    Science.gov (United States)

    Tao, Jie; Lu, Renquan; Shi, Peng; Su, Hongye; Wu, Zheng-Guang

    2017-09-01

    This paper is concerned with the problem of reliable dissipative control for Takagi-Sugeno fuzzy systems with Markov jumping parameters. Considering the influence of actuator faults, a sufficient condition is developed to ensure that the resultant closed-loop system is stochastically stable and strictly ( Q, S,R )-dissipative based on a relaxed approach in which mode-dependent and fuzzy-basis-dependent Lyapunov functions are employed. Then a reliable dissipative control for fuzzy Markov jump systems is designed, with sufficient condition proposed for the existence of guaranteed stability and dissipativity controller. The effectiveness and potential of the obtained design method is verified by two simulation examples.

  11. Electrostatically Driven Nanoballoon Actuator.

    Science.gov (United States)

    Barzegar, Hamid Reza; Yan, Aiming; Coh, Sinisa; Gracia-Espino, Eduardo; Dunn, Gabriel; Wågberg, Thomas; Louie, Steven G; Cohen, Marvin L; Zettl, Alex

    2016-11-09

    We demonstrate an inflatable nanoballoon actuator based on geometrical transitions between the inflated (cylindrical) and collapsed (flattened) forms of a carbon nanotube. In situ transmission electron microscopy experiments employing a nanoelectromechanical manipulator show that a collapsed carbon nanotube can be reinflated by electrically charging the nanotube, thus realizing an electrostatically driven nanoballoon actuator. We find that the tube actuator can be reliably cycled with only modest control voltages (few volts) with no apparent wear or fatigue. A complementary theoretical analysis identifies critical parameters for nanotube nanoballoon actuation.

  12. High-speed tracking control of piezoelectric actuators using an ellipse-based hysteresis model.

    Science.gov (United States)

    Gu, Guoying; Zhu, Limin

    2010-08-01

    In this paper, an ellipse-based mathematic model is developed to characterize the rate-dependent hysteresis in piezoelectric actuators. Based on the proposed model, an expanded input space is constructed to describe the multivalued hysteresis function H[u](t) by a multiple input single output (MISO) mapping Gamma:R(2)-->R. Subsequently, the inverse MISO mapping Gamma(-1)(H[u](t),H[u](t);u(t)) is proposed for real-time hysteresis compensation. In controller design, a hybrid control strategy combining a model-based feedforward controller and a proportional integral differential (PID) feedback loop is used for high-accuracy and high-speed tracking control of piezoelectric actuators. The real-time feedforward controller is developed to cancel the rate-dependent hysteresis based on the inverse hysteresis model, while the PID controller is used to compensate for the creep, modeling errors, and parameter uncertainties. Finally, experiments with and without hysteresis compensation are conducted and the experimental results are compared. The experimental results show that the hysteresis compensation in the feedforward path can reduce the hysteresis-caused error by up to 88% and the tracking performance of the hybrid controller is greatly improved in high-speed tracking control applications, e.g., the root-mean-square tracking error is reduced to only 0.34% of the displacement range under the input frequency of 100 Hz.

  13. Nonlinear dynamic modeling of a V-shaped metal based thermally driven MEMS actuator for RF switches

    Science.gov (United States)

    Bakri-Kassem, Maher; Dhaouadi, Rached; Arabi, Mohamed; Estahbanati, Shahabeddin V.; Abdel-Rahman, Eihab

    2018-05-01

    In this paper, we propose a new dynamic model to describe the nonlinear characteristics of a V-shaped (chevron) metallic-based thermally driven MEMS actuator. We developed two models for the thermal actuator with two configurations. The first MEMS configuration has a small tip connected to the shuttle, while the second configuration has a folded spring and a wide beam attached to the shuttle. A detailed finite element model (FEM) and a lumped element model (LEM) are proposed for each configuration to completely characterize the electro-thermal and thermo-mechanical behaviors. The nonlinear resistivity of the polysilicon layer is extracted from the measured current-voltage (I-V) characteristics of the actuator and the simulated corresponding temperatures in the FEM model, knowing the resistivity of the polysilicon at room temperature from the manufacture’s handbook. Both developed models include the nonlinear temperature-dependent material properties. Numerical simulations in comparison with experimental data using a dedicated MEMS test apparatus verify the accuracy of the proposed LEM model to represent the complex dynamics of the thermal MEMS actuator. The LEM and FEM simulation results show an accuracy ranging from a maximum of 13% error down to a minimum of 1.4% error. The actuator with the lower thermal load to air that includes a folded spring (FS), also known as high surface area actuator is compared to the actuator without FS, also known as low surface area actuator, in terms of the I-V characteristics, power consumption, and experimental static and dynamic responses of the tip displacement.

  14. Feedforward-feedback hybrid control for magnetic shape memory alloy actuators based on the Krasnosel'skii-Pokrovskii model.

    Directory of Open Access Journals (Sweden)

    Miaolei Zhou

    Full Text Available As a new type of smart material, magnetic shape memory alloy has the advantages of a fast response frequency and outstanding strain capability in the field of microdrive and microposition actuators. The hysteresis nonlinearity in magnetic shape memory alloy actuators, however, limits system performance and further application. Here we propose a feedforward-feedback hybrid control method to improve control precision and mitigate the effects of the hysteresis nonlinearity of magnetic shape memory alloy actuators. First, hysteresis nonlinearity compensation for the magnetic shape memory alloy actuator is implemented by establishing a feedforward controller which is an inverse hysteresis model based on Krasnosel'skii-Pokrovskii operator. Secondly, the paper employs the classical Proportion Integration Differentiation feedback control with feedforward control to comprise the hybrid control system, and for further enhancing the adaptive performance of the system and improving the control accuracy, the Radial Basis Function neural network self-tuning Proportion Integration Differentiation feedback control replaces the classical Proportion Integration Differentiation feedback control. Utilizing self-learning ability of the Radial Basis Function neural network obtains Jacobian information of magnetic shape memory alloy actuator for the on-line adjustment of parameters in Proportion Integration Differentiation controller. Finally, simulation results show that the hybrid control method proposed in this paper can greatly improve the control precision of magnetic shape memory alloy actuator and the maximum tracking error is reduced from 1.1% in the open-loop system to 0.43% in the hybrid control system.

  15. Feedforward-feedback hybrid control for magnetic shape memory alloy actuators based on the Krasnosel'skii-Pokrovskii model.

    Science.gov (United States)

    Zhou, Miaolei; Zhang, Qi; Wang, Jingyuan

    2014-01-01

    As a new type of smart material, magnetic shape memory alloy has the advantages of a fast response frequency and outstanding strain capability in the field of microdrive and microposition actuators. The hysteresis nonlinearity in magnetic shape memory alloy actuators, however, limits system performance and further application. Here we propose a feedforward-feedback hybrid control method to improve control precision and mitigate the effects of the hysteresis nonlinearity of magnetic shape memory alloy actuators. First, hysteresis nonlinearity compensation for the magnetic shape memory alloy actuator is implemented by establishing a feedforward controller which is an inverse hysteresis model based on Krasnosel'skii-Pokrovskii operator. Secondly, the paper employs the classical Proportion Integration Differentiation feedback control with feedforward control to comprise the hybrid control system, and for further enhancing the adaptive performance of the system and improving the control accuracy, the Radial Basis Function neural network self-tuning Proportion Integration Differentiation feedback control replaces the classical Proportion Integration Differentiation feedback control. Utilizing self-learning ability of the Radial Basis Function neural network obtains Jacobian information of magnetic shape memory alloy actuator for the on-line adjustment of parameters in Proportion Integration Differentiation controller. Finally, simulation results show that the hybrid control method proposed in this paper can greatly improve the control precision of magnetic shape memory alloy actuator and the maximum tracking error is reduced from 1.1% in the open-loop system to 0.43% in the hybrid control system.

  16. A soft biomolecule actuator based on a highly functionalized bacterial cellulose nano-fiber network with carboxylic acid groups.

    Science.gov (United States)

    Wang, Fan; Jeon, Jin-Han; Park, Sukho; Kee, Chang-Doo; Kim, Seong-Jun; Oh, Il-Kwon

    2016-01-07

    Upcoming human-related applications such as soft wearable electronics, flexible haptic systems, and active bio-medical devices will require bio-friendly actuating materials. Here, we report a soft biomolecule actuator based on carboxylated bacterial cellulose (CBC), ionic liquid (IL), and poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) ( PSS) electrodes. Soft and biocompatible polymer-IL composites were prepared via doping of CBC with ILs. The highly conductive PSS layers were deposited on both sides of the CBC-IL membranes by a dip-coating technique to yield a sandwiched actuator system. Ionic conductivity and ionic exchange capacity of the CBC membrane can be increased up to 22.8 times and 1.5 times compared with pristine bacterial cellulose (BC), respectively, resulting in 8 times large bending deformation than the pure BC actuators with metallic electrodes in an open air environment. The developed CBC-IL actuators show significant progress in the development of biocompatible and soft actuating materials with quick response, low operating voltage and comparatively large bending deformation.

  17. Large angle and high linearity two-dimensional laser scanner based on voice coil actuators

    Science.gov (United States)

    Wu, Xin; Chen, Sihai; Chen, Wei; Yang, Minghui; Fu, Wen

    2011-10-01

    A large angle and high linearity two-dimensional laser scanner with an in-house ingenious deflection angle detecting system is developed based on voice coil actuators direct driving mechanism. The specially designed voice coil actuators make the steering mirror moving at a sufficiently large angle. Frequency sweep method based on virtual instruments is employed to achieve the natural frequency of the laser scanner. The response shows that the performance of the laser scanner is limited by the mechanical resonances. The closed-loop controller based on mathematical model is used to reduce the oscillation of the laser scanner at resonance frequency. To design a qualified controller, the model of the laser scanner is set up. The transfer function of the model is identified with MATLAB according to the tested data. After introducing of the controller, the nonlinearity decreases from 13.75% to 2.67% at 50 Hz. The laser scanner also has other advantages such as large deflection mirror, small mechanical structure, and high scanning speed.

  18. Compensator design for hysteresis of a stacked PZT actuator using a congruency-based hysteresis model

    International Nuclear Information System (INIS)

    Nguyen, Phuong-Bac; Choi, Seung-Bok

    2012-01-01

    This paper proposes a rate-independent hysteresis compensator for a stacked PZT (lead zirconate titanate) actuator. From a congruency-based hysteresis (CBH) model which is derived from the inherent properties of this actuator, especially the congruency, a feedforward compensator associated with it is developed. The formulation of the proposed compensator is based on an assumption that the inverse operator also possesses the same properties as the CBH model does. This implies that the compensator also possesses properties such as the wiped-out loop closing between the consecutive control points and congruency. Consequently, the expressions for the compensator can be conducted by exploiting the equations for the CBH model in two cases of monotonic increase and monotonic decrease of input excitation. In order to assess the performance of the compensator, several experiments in both open-loop and closed-loop controls are undertaken. In the open-loop control experiment, the performance of the feedforward compensator using the CBH model is compared with the classical Preisach model-based one in three cases of reference waveforms. In the closed-loop control experiment, the proposed compensator is incorporated into a PID (proportional-integral-derivative) control system and the performance of this integrated system is then evaluated and compared to that of the PID with and without compensator. (paper)

  19. Development of a Flat Type Six-Axis Stage Based on Piezoelectric Actuators

    Directory of Open Access Journals (Sweden)

    Hau-Wei Lee

    2014-01-01

    Full Text Available This study presents and investigates a six-DOF (degrees of freedom piezoelectric based stage for positioning error compensation. The relationship between the displacement of the piezoelectric actuators and the stage can be computed according to the geometric relationships of the actuators installed. In this study, a feedforward compensator based on the hysteresis model has been designed for compensation and a PI controller was used for positioning. The combination of a feedforward compensator and PI controller gives the stage good positioning and tracking performance. Stage position information is feedback from a six-DOF optical measurement system comprised of three modular two-dimensional measurement devices. Each module employs a quadrant photodiode (QPD, a laser diode, and a lens. The measurement signal is acquired and processed using an FPGA based processor for real time control. The linear and angular positioning resolution is 0.02 μm and 0.1 arcsec, respectively. When the stage is controlled in a closed loop, the positioning errors are in the range of ±0.1 μm and ±0.5 arcsec. The stage is controlled to track a sinusoidal wave with an amplitude of 2.5 μm and a frequency of 5 Hz; tracking errors were within ±0.1 μm and ±0.2 arcsec.

  20. Mapping real-life applications on run-time reconfigurable NoC-based MPSoC on FPGA.

    NARCIS (Netherlands)

    Singh, A.K.; Kumar, A.; Srikanthan, Th.; Ha, Y.

    2010-01-01

    Multiprocessor systems-on-chip (MPSoC) are required to fulfill the performance demand of modern real-life embedded applications. These MPSoCs are employing Network-on-Chip (NoC) for reasons of efficiency and scalability. Additionally, these systems need to support run-time reconfiguration of their

  1. Tunable and reconfigurable microwave filter by use of a Bragg-grating-based acousto-optic superlattice modulator.

    Science.gov (United States)

    Delgado-Pinar, M; Mora, J; Díez, A; Andrés, M V; Ortega, B; Capmany, J

    2005-01-01

    We present an all-optical novel configuration for implementing multitap transversal filters by use of a broadband source sliced by fiber Bragg grating arrays generated by propagating an acoustic wave along a strong uniform fiber Bragg grating. The tunability and reconfigurability of the microwave filter are demonstrated.

  2. Bistable out-of-plane stress-mismatched thermally actuated bilayer devices with large deflection

    International Nuclear Information System (INIS)

    Goessling, B A; Lucas, T M; Moiseeva, E V; Aebersold, J W; Harnett, C K

    2011-01-01

    In this paper, we explore microfabricated bistable actuators released as thin films from a silicon wafer. The actuators are based on a serpentine design where two cantilevers are coupled at the tips by a thin-film bar. These devices are parameterized by two lengths: cantilever length and the length of the coupling bar. These two dimensions are systematically varied to study the effect of design parameters on bistability. The three-dimensional devices have extremely large deflection (hundreds of microns rather than tens of microns for most planar microactuators of similar size) and are thermally actuated out of the plane of the wafer by applying a bias across either the left or right side of the serpentine. The bistability of these devices is evaluated using electron and optical microscopy. Potential applications include non-volatile mechanical memory, optical shutters, and reconfigurable antenna elements

  3. Reconfiguration of distribution nets

    International Nuclear Information System (INIS)

    Latorre Bayona, Gerardo; Angarita Marquez, Jorge Luis

    2000-01-01

    Starting of the location of the reconfiguration problem inside the context of the operation of distribution nets, of the quality indicators definition and of the presentation of the alternatives more used for reduction of technical losses, they are related diverse reconfiguration methodologies proposed in the technical literature, pointing out their three principals limitations; also are presents the results of lost obtained starting from simulation works carried out in distribution circuits of the ESSA ESP, which permitting to postulate the reconfiguration of nets like an excellent alternative to reduce technical losses

  4. Neural networks based identification and compensation of rate-dependent hysteresis in piezoelectric actuators

    International Nuclear Information System (INIS)

    Zhang, Xinliang; Tan, Yonghong; Su, Miyong; Xie, Yangqiu

    2010-01-01

    This paper presents a method of the identification for the rate-dependent hysteresis in the piezoelectric actuator (PEA) by use of neural networks. In this method, a special hysteretic operator is constructed from the Prandtl-Ishlinskii (PI) model to extract the changing tendency of the static hysteresis. Then, an expanded input space is constructed by introducing the proposed hysteretic operator to transform the multi-valued mapping of the hysteresis into a one-to-one mapping. Thus, a feedforward neural network is applied to the approximation of the rate-independent hysteresis on the constructed expanded input space. Moreover, in order to describe the rate-dependent performance of the hysteresis, a special hybrid model, which is constructed by a linear auto-regressive exogenous input (ARX) sub-model preceded with the previously obtained neural network based rate-independent hysteresis sub-model, is proposed. For the compensation of the effect of the hysteresis in PEA, the PID feedback controller with a feedforward hysteresis compensator is developed for the tracking control of the PEA. Thus, a corresponding inverse model based on the proposed modeling method is developed for the feedforward hysteresis compensator. Finally, both simulations and experimental results on piezoelectric actuator are presented to verify the effectiveness of the proposed approach for the rate-dependent hysteresis.

  5. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    Science.gov (United States)

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

  6. A Preliminary Investigation of Temperature Dependency of a Shape Memory Actuator with Time-Based Control in Aircraft Interiors

    Science.gov (United States)

    Otibar, Dennis; Weirich, Antonia; Kortenjann, Marcus; Kuhlenkötter, Bernd

    2017-06-01

    Shape memory alloys (SMA) possess an array of unique functional properties which are influenced by a complex interaction of different factors. Due to thermal sensitivity, slight changes in the environmental temperature may cause the properties to change significantly. This poses a huge challenge especially for the use of SMAs as actuators. The most common and elementary activation strategy of SMA actuators is based on the duration of activation and cooling with constant activation parameters. However, changing environmental influences cause the necessity to modify these parameters. This circumstance needs to be especially considered in the design process of actuator controls. This paper focuses on investigating the influence of environmental temperature changes on time-based activated SMA actuators. The results of the described experiments form the base for designing reactive control strategies for SMA actuators used in alternating environments. An example for application fields with changing environments and particularly changing temperatures are aircraft related implementations. This area also stands to benefit from the actuators’ advantages in ecological efficiency.

  7. Fabrication of wrist-like SMA-based actuator by double smart soft composite casting

    Science.gov (United States)

    Rodrigue, Hugo; Wei, Wang; Bhandari, Binayak; Ahn, Sung-Hoon

    2015-12-01

    A new manufacturing method for smart soft composite (SSC) actuators that consists of double casting a SSC actuator to produce an actuator with non-linear shape memory alloy (SMA) wire positioning is proposed. This method is used to manufacture a tube-shaped SSC actuator in which the SMA wires follow the curvature of the tube and is capable of pure-twisting deformations while sustaining a cantilever load. The concept is tested by measuring the maximum twisting angle and a simple control method is proposed to control the twisting angle of the actuator. Then, a soft robotic wrist with a length of 18 cm is built, its load-carrying capability is tested by measuring the cantilever force required for deforming the actuator, and its load-carrying capability during actuation is tested by loading one end with different objects and actuating the actuator. This wrist actuator shows good repeatability, is capable of twisting deformations up to 25° while holding objects weighing 100 g, and can sustain loads above 2 N without undergoing buckling.

  8. Fabrication of wrist-like SMA-based actuator by double smart soft composite casting

    International Nuclear Information System (INIS)

    Rodrigue, Hugo; Wei, Wang; Bhandari, Binayak; Ahn, Sung-Hoon

    2015-01-01

    A new manufacturing method for smart soft composite (SSC) actuators that consists of double casting a SSC actuator to produce an actuator with non-linear shape memory alloy (SMA) wire positioning is proposed. This method is used to manufacture a tube-shaped SSC actuator in which the SMA wires follow the curvature of the tube and is capable of pure-twisting deformations while sustaining a cantilever load. The concept is tested by measuring the maximum twisting angle and a simple control method is proposed to control the twisting angle of the actuator. Then, a soft robotic wrist with a length of 18 cm is built, its load-carrying capability is tested by measuring the cantilever force required for deforming the actuator, and its load-carrying capability during actuation is tested by loading one end with different objects and actuating the actuator. This wrist actuator shows good repeatability, is capable of twisting deformations up to 25° while holding objects weighing 100 g, and can sustain loads above 2 N without undergoing buckling. (paper)

  9. Attention-based navigation in mobile robots using a reconfigurable sensor

    NARCIS (Netherlands)

    Maris, M.

    2001-01-01

    In this paper, a method for visual attentional selection in mobile robots is proposed, based on amplification of the selected stimulus. Attention processing is performed on the vision sensor, which is integrated on a silicon chip and consists of a contrast sensitive retina with the ability to change

  10. An Efficient FFT For OFDM Based Cognitive Radio On A Reconfigurable Architecture

    NARCIS (Netherlands)

    Zhang, Q.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

    2007-01-01

    Cognitive Radio is a promising technology to utilize non-used parts of the spectrum that actually are assigned to licensed services. An adaptive OFDM based Cognitive Radio system has the capacity to nullify individual carriers to avoid interference to the licensed user. Therefore, there could be a

  11. Ripples in Communication : Reconfigurable and Adaptive Wireless Communication Systems based on Wavelet Packet Modulators

    NARCIS (Netherlands)

    Lakshmanan, M.K.

    2011-01-01

    Wavelet Packet Modulation (WPM) is a multi-carrier transmission technique that uses orthogonal wavelet packet bases to combine a collection of information bits into a single composite signal. This system can be considered as a viable alternative, for wide-band communication, to the popular

  12. Energy-aware SQL query acceleration through FPGA-based dynamic partial reconfiguration

    NARCIS (Netherlands)

    Becher, Andreas; Bauer, Florian; Ziener, Daniel; Teich, Jürgen

    2014-01-01

    In this paper, we propose an approach for energy-aware FPGA-based query acceleration for databases on embedded devices. After the analysis of an incoming query, a query-specific hardware accelerator is generated on-the-fly and loaded on the FPGA for subsequent query execution using partial dynamic

  13. Dynamic Reconfiguration of a RGBD Sensor Based on QoS and QoC Requirements in Distributed Systems.

    Science.gov (United States)

    Munera, Eduardo; Poza-Lujan, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, José-Enrique; Noguera, Juan Fco Blanes

    2015-07-24

    The inclusion of embedded sensors into a networked system provides useful information for many applications. A Distributed Control System (DCS) is one of the clearest examples where processing and communications are constrained by the client's requirements and the capacity of the system. An embedded sensor with advanced processing and communications capabilities supplies high level information, abstracting from the data acquisition process and objects recognition mechanisms. The implementation of an embedded sensor/actuator as a Smart Resource permits clients to access sensor information through distributed network services. Smart resources can offer sensor services as well as computing, communications and peripheral access by implementing a self-aware based adaptation mechanism which adapts the execution profile to the context. On the other hand, information integrity must be ensured when computing processes are dynamically adapted. Therefore, the processing must be adapted to perform tasks in a certain lapse of time but always ensuring a minimum process quality. In the same way, communications must try to reduce the data traffic without excluding relevant information. The main objective of the paper is to present a dynamic configuration mechanism to adapt the sensor processing and communication to the client's requirements in the DCS. This paper describes an implementation of a smart resource based on a Red, Green, Blue, and Depth (RGBD) sensor in order to test the dynamic configuration mechanism presented.

  14. Finite element analysis of displacement actuator based on giant magnetostrictive thin film

    Directory of Open Access Journals (Sweden)

    Shaopeng Yu

    2018-05-01

    Full Text Available With the rapid development of science and technology, mechanical and electrical equipment become more and more miniature. In order to achieve precise control in less than 1cm3, the giant magnetostrictive thin film has become a research hotspot. The micro displacement actuator with planar and arc film is designed by the dynamic coupling model based on J-A model and magneto-mechanical effect method which is proposed in this paper. The different structure and thickness of films are analyzed by COMSOL Multiphysics software when the current flows through driving coil. After comparing the simulation results with the test ones, it can be seen that the coupling model is accurate and the structure is reliable. At the same time, MATLAB is used to fit the current density-displacement curve and higher order equation is obtained, and then the feasibility of design can be verified. The actuator with arc structure had advantages of small volume, fast response, high precision, easy integration, etc., which has a broad application prospect in the field of vibration control, micro positioning, robot and so on.

  15. Finite element analysis of displacement actuator based on giant magnetostrictive thin film

    Science.gov (United States)

    Yu, Shaopeng; Wang, Bowen; Zhang, Changgeng; Cui, Baozhi

    2018-05-01

    With the rapid development of science and technology, mechanical and electrical equipment become more and more miniature. In order to achieve precise control in less than 1cm3, the giant magnetostrictive thin film has become a research hotspot. The micro displacement actuator with planar and arc film is designed by the dynamic coupling model based on J-A model and magneto-mechanical effect method which is proposed in this paper. The different structure and thickness of films are analyzed by COMSOL Multiphysics software when the current flows through driving coil. After comparing the simulation results with the test ones, it can be seen that the coupling model is accurate and the structure is reliable. At the same time, MATLAB is used to fit the current density-displacement curve and higher order equation is obtained, and then the feasibility of design can be verified. The actuator with arc structure had advantages of small volume, fast response, high precision, easy integration, etc., which has a broad application prospect in the field of vibration control, micro positioning, robot and so on.

  16. LMI-based adaptive reliable H∞ static output feedback control against switched actuator failures

    Science.gov (United States)

    An, Liwei; Zhai, Ding; Dong, Jiuxiang; Zhang, Qingling

    2017-08-01

    This paper investigates the H∞ static output feedback (SOF) control problem for switched linear system under arbitrary switching, where the actuator failure models are considered to depend on switching signal. An active reliable control scheme is developed by combination of linear matrix inequality (LMI) method and adaptive mechanism. First, by exploiting variable substitution and Finsler's lemma, new LMI conditions are given for designing the SOF controller. Compared to the existing results, the proposed design conditions are more relaxed and can be applied to a wider class of no-fault linear systems. Then a novel adaptive mechanism is established, where the inverses of switched failure scaling factors are estimated online to accommodate the effects of actuator failure on systems. Two main difficulties arise: first is how to design the switched adaptive laws to prevent the missing of estimating information due to switching; second is how to construct a common Lyapunov function based on a switched estimate error term. It is shown that the new method can give less conservative results than that for the traditional control design with fixed gain matrices. Finally, simulation results on the HiMAT aircraft are given to show the effectiveness of the proposed approaches.

  17. Reconfigurable Sensor Monitoring System

    Science.gov (United States)

    Alhorn, Dean C. (Inventor); Dutton, Kenneth R. (Inventor); Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2017-01-01

    A reconfigurable sensor monitoring system includes software tunable filters, each of which is programmable to condition one type of analog signal. A processor coupled to the software tunable filters receives each type of analog signal so-conditioned.

  18. Neural networks dynamic hysteresis model for piezoceramic actuator based on hysteresis operator of first-order differential equation

    International Nuclear Information System (INIS)

    Dang Xuanju; Tan Yonghong

    2005-01-01

    A new neural networks dynamic hysteresis model for piezoceramic actuator is proposed by combining the Preisach model with diagonal recurrent neural networks. The Preisach model is based on elementary rate-independent operators and is not suitable for modeling piezoceramic actuator across a wide frequency band because of the rate-dependent hysteresis characteristic of the piezoceramic actuator. The structure of the developed model is based on the structure of the Preisach model, in which the rate-independent relay hysteresis operators (cells) are replaced by the rate-dependent hysteresis operators of first-order differential equation. The diagonal recurrent neural networks being modified by an adjustable factor can be used to model the hysteresis behavior of the pizeoceramic actuator because its structure is similar to the structure of the modified Preisach model. Therefore, the proposed model not only possesses that of the Preisach model, but also can be used for describing its dynamic hysteresis behavior. Through the experimental results of both the approximation and the prediction, the effectiveness of the neural networks dynamic hysteresis model for the piezoceramic actuator is demonstrated

  19. Miniaturized and reconfigurable notch antenna based on a BST ferroelectric thin film

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Hung Viet [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); CEA-LETI, Minatec, 17 avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Benzerga, Ratiba, E-mail: ratiba.benzerga@univ-rennes1.fr [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); Borderon, Caroline [IETR, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes (France); Delaveaud, Christophe [CEA-LETI, Minatec, 17 avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Sharaiha, Ala [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); Renoud, Raphael [IETR, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes (France); Paven, Claire Le [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); Pavy, Sabrina; Nadaud, Kevin; Gundel, Hartmut W. [IETR, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes (France)

    2015-07-15

    Highlights: • A miniature and agile antenna based on a BST MIM capacitor is simulated and made. • Mn{sup 2+} doped BST thin films are synthesized by chemical deposition and spin coating. • Permittivity and losses of the BST thin film are respectively 225 and 0.02 at 1 GHz. • A miniaturization rate of 70% is obtained with a MIM capacitance of 3.7 pF. • A frequency tunability of 14.5% and a tunability performance of 0.04 are measured. - Abstract: This work deals with the design, realization and characterization of a miniature and frequency agile antenna based on a ferroelectric Ba{sub 0,80}Sr{sub 0,20}TiO{sub 3} thin film. The notch antenna is loaded with a variable metal/insulator/metal (MIM) capacitor and is achieved by a monolithic method. The MIM capacitance is 3.7 pF, which results in a resonant frequency of 670 MHz compared to 2.25 GHz for the unloaded simulated antenna; the resulting miniaturization rate is 70%. The characterization of the antenna prototype shows a frequency tunable rate of 14.5% under an electric field of 375 kV/cm, with a tunability performance η = 0.04.

  20. Towards a digital sound reconstruction MEMS device: Characterization of a single PZT based piezoelectric actuator

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2015-04-01

    In this paper we report the fabrication and characterization of a single piezoelectric actuator for digital sound reconstruction. This work is the first step towards the implementation of a true digital micro-loudspeaker by means of an array of acoustic actuators. These actuators consist of a flexible membrane fabricated using polyimide, which is actuated using a Lead-Zirconate-Titanate (PZT) piezoelectric ceramic layer working in the d31 actuation mode. The dimensions of the membrane are of 1mm diameter and 4μm in thickness, which is capable of being symmetrically actuated in both upward and downward directions, due to the back etch step releasing the membrane. Our electrical characterization shows an improvement in the polarization of the piezoelectric material after its final etch patterning step, and our mechanical characterization shows the natural modes of resonance of the stacked membrane. © 2015 IEEE.

  1. Bioinspired Smart Actuator Based on Graphene Oxide-Polymer Hybrid Hydrogels.

    Science.gov (United States)

    Wang, Tao; Huang, Jiahe; Yang, Yiqing; Zhang, Enzhong; Sun, Weixiang; Tong, Zhen

    2015-10-28

    Rapid response and strong mechanical properties are desired for smart materials used in soft actuators. A bioinspired hybrid hydrogel actuator was designed and prepared by series combination of three trunks of tough polymer-clay hydrogels to accomplish the comprehensive actuation of "extension-grasp-retraction" like a fishing rod. The hydrogels with thermo-creep and thermo-shrinking features were successively irradiated by near-infrared (NIR) to execute extension and retraction, respectively. The GO in the hydrogels absorbed the NIR energy and transformed it into thermo-energy rapidly and effectively. The hydrogel with adhesion or magnetic force was adopted as the "hook" of the hybrid hydrogel actuator for grasping object. The hook of the hybrid hydrogel actuator was replaceable according to applications, even with functional materials other than hydrogels. This study provides an innovative concept to explore new soft actuators through combining response hydrogels and programming the same stimulus.

  2. Reconfiguration of face expressions based on the discrete capture data of radial basis function interpolation

    Institute of Scientific and Technical Information of China (English)

    ZHENG Guangguo; ZHOU Dongsheng; WEI Xiaopeng; ZHANG Qiang

    2012-01-01

    Compactly supported radial basis function can enable the coefficient matrix of solving weigh linear system to have a sparse banded structure, thereby reducing the complexity of the algorithm. Firstly, based on the compactly supported radial basis function, the paper makes the complex quadratic function (Multiquadric, MQ for short) to be transformed and proposes a class of compactly supported MQ function. Secondly, the paper describes a method that interpolates discrete motion capture data to solve the motion vectors of the interpolation points and they are used in facial expression reconstruction. Finally, according to this characteris- tic of the uneven distribution of the face markers, the markers are numbered and grouped in accordance with the density level, and then be interpolated in line with each group. The approach not only ensures the accuracy of the deformation of face local area and smoothness, but also reduces the time complexity of computing.

  3. Improved control of distributed parameter systems using wireless sensor and actuator networks: An observer-based method

    International Nuclear Information System (INIS)

    Jiang Zheng-Xian; Cui Bao-Tong; Lou Xu-Yang; Zhuang Bo

    2017-01-01

    In this paper, the control problem of distributed parameter systems is investigated by using wireless sensor and actuator networks with the observer-based method. Firstly, a centralized observer which makes use of the measurement information provided by the fixed sensors is designed to estimate the distributed parameter systems. The mobile agents, each of which is affixed with a controller and an actuator, can provide the observer-based control for the target systems. By using Lyapunov stability arguments, the stability for the estimation error system and distributed parameter control system is proved, meanwhile a guidance scheme for each mobile actuator is provided to improve the control performance. A numerical example is finally used to demonstrate the effectiveness and the advantages of the proposed approaches. (paper)

  4. Low-voltage, large-strain soft electrothermal actuators based on laser-reduced graphene oxide/Ag particle composites

    Science.gov (United States)

    Wang, Qian; Li, Yu-Tao; Zhang, Tian-Yu; Wang, Dan-Yang; Tian, Ye; Yan, Jun-Chao; Tian, He; Yang, Yi; Yang, Fan; Ren, Tian-Ling

    2018-03-01

    In this paper, low-voltage, large-strain flexible electrothermal actuators (ETAs) based on laser-reduced graphene oxide (LRGO)/Ag particle composites were fabricated in a simple and cost-efficient process. By adding Ag particles to the LRGO, the sheet resistance decreased effectively. Under a driving voltage of 28 V, the actuator obtained a bending angle of 192° within 6 s. Besides, the bending deformation could be precisely controlled by the driving voltage ranging from 10° to 192°. Finally, a gripper composed of two actuators was demonstrated to manipulate a piece of polydimethylsiloxane block. With the advantages of low-voltage, fast-response, and easy-to-manufacture, the graphene based ETAs have a promising application in soft robotics and soft machines.

  5. Size-dependent pull-in instability of electrostatically actuated microbeam-based MEMS

    International Nuclear Information System (INIS)

    Wang, Binglei; Zhou, Shenjie; Zhao, Junfeng; Chen, Xi

    2011-01-01

    We present a size-dependent model for electrostatically actuated microbeam-based MEMS using strain gradient elasticity theory. The normalized pull-in voltage is shown to increase nonlinearly with the decrease of the beam height, and the size effect becomes prominent if the beam thickness is on the order of microns or smaller (i.e. when the beam dimension is comparable to the material length scale parameter). Very good agreement is found between the present model and available experimental data. The study may be helpful to characterize the mechanical properties of small size MEMS, or guide the design of microbeam-based devices for a wide range of potential applications. (technical note)

  6. Controllable nanoscale rotating actuator system based on carbon nanotube and graphene

    International Nuclear Information System (INIS)

    Huang, Jianzhang; Han, Qiang

    2016-01-01

    A controllable nanoscale rotating actuator system consisting of a double carbon nanotube and graphene driven by a temperature gradient is proposed, and its rotating dynamics performance and driving mechanism are investigated through molecular dynamics simulations. The outer tube exhibits stable pure rotation with certain orientation under temperature gradient and the steady rotational speed rises as the temperature gradient increases. It reveals that the driving torque is caused by the difference of atomic van der Waals potentials due to the temperature gradient and geometrical features of carbon nanotube. A theoretical model for driving torque is established based on lattice dynamics theory and its predicted results agree well with molecular dynamics simulations. Further discussion is taken according to the theoretical model. The work in this study would be a guide for design and application of controllable nanoscale rotating devices based on carbon nanotubes and graphene. (paper)

  7. Risk-based reconfiguration of safety monitoring system using dynamic Bayesian network

    International Nuclear Information System (INIS)

    Kohda, Takehisa; Cui Weimin

    2007-01-01

    To prevent an abnormal event from leading to an accident, the role of its safety monitoring system is very important. The safety monitoring system detects symptoms of an abnormal event to mitigate its effect at its early stage. As the operation time passes by, the sensor reliability decreases, which implies that the decision criteria of the safety monitoring system should be modified depending on the sensor reliability as well as the system reliability. This paper presents a framework for the decision criteria (or diagnosis logic) of the safety monitoring system. The logic can be dynamically modified based on sensor output data monitored at regular intervals to minimize the expected loss caused by two types of safety monitoring system failure events: failed-dangerous (FD) and failed-safe (FS). The former corresponds to no response under an abnormal system condition, while the latter implies a spurious activation under a normal system condition. Dynamic Bayesian network theory can be applied to modeling the entire system behavior composed of the system and its safety monitoring system. Using the estimated state probabilities, the optimal decision criterion is given to obtain the optimal diagnosis logic. An illustrative example of a three-sensor system shows the merits and characteristics of the proposed method, where the reasonable interpretation of sensor data can be obtained

  8. Virtual Character Animation Based on Affordable Motion Capture and Reconfigurable Tangible Interfaces.

    Science.gov (United States)

    Lamberti, Fabrizio; Paravati, Gianluca; Gatteschi, Valentina; Cannavo, Alberto; Montuschi, Paolo

    2018-05-01

    Software for computer animation is generally characterized by a steep learning curve, due to the entanglement of both sophisticated techniques and interaction methods required to control 3D geometries. This paper proposes a tool designed to support computer animation production processes by leveraging the affordances offered by articulated tangible user interfaces and motion capture retargeting solutions. To this aim, orientations of an instrumented prop are recorded together with animator's motion in the 3D space and used to quickly pose characters in the virtual environment. High-level functionalities of the animation software are made accessible via a speech interface, thus letting the user control the animation pipeline via voice commands while focusing on his or her hands and body motion. The proposed solution exploits both off-the-shelf hardware components (like the Lego Mindstorms EV3 bricks and the Microsoft Kinect, used for building the tangible device and tracking animator's skeleton) and free open-source software (like the Blender animation tool), thus representing an interesting solution also for beginners approaching the world of digital animation for the first time. Experimental results in different usage scenarios show the benefits offered by the designed interaction strategy with respect to a mouse & keyboard-based interface both for expert and non-expert users.

  9. Field programmable gate array based reconfigurable scanning probe/optical microscope.

    Science.gov (United States)

    Nowak, Derek B; Lawrence, A J; Dzegede, Zechariah K; Hiester, Justin C; Kim, Cliff; Sánchez, Erik J

    2011-10-01

    The increasing popularity of nanometrology and nanospectroscopy has pushed researchers to develop complex new analytical systems. This paper describes the development of a platform on which to build a microscopy tool that will allow for flexibility of customization to suit research needs. The novelty of the described system lies in its versatility of capabilities. So far, one version of this microscope has allowed for successful near-field and far-field fluorescence imaging with single molecule detection sensitivity. This system is easily adapted for reflection, polarization (Kerr magneto-optical (MO)), Raman, super-resolution techniques, and other novel scanning probe imaging and spectroscopic designs. While collecting a variety of forms of optical images, the system can simultaneously monitor topographic information of a sample with an integrated tuning fork based shear force system. The instrument has the ability to image at room temperature and atmospheric pressure or under liquid. The core of the design is a field programmable gate array (FPGA) data acquisition card and a single, low cost computer to control the microscope with analog control circuitry using off-the-shelf available components. A detailed description of electronics, mechanical requirements, and software algorithms as well as examples of some different forms of the microscope developed so far are discussed.

  10. Design and experimental characterization of a NiTi-based, high-frequency, centripetal peristaltic actuator

    International Nuclear Information System (INIS)

    Borlandelli, E; Scarselli, D; Bettini, P; Morandini, M; Sala, G; Quadrio, M; Nespoli, A; Rigamonti, D; Villa, E

    2015-01-01

    Development and experimental testing of a peristaltic device actuated by a single shape-memory NiTi wire are described. The actuator is designed to radially shrink a compliant silicone pipe, and must work on a sustained basis at an actuation frequency that is higher than those typical of NiTi actuators. Four rigid, aluminum-made circular sectors are sitting along the pipe circumference and provide the required NiTi wire housing. The aluminum assembly acts as geometrical amplifier of the wire contraction and as heat sink required to dissipate the thermal energy of the wire during the cooling phase. We present and discuss the full experimental investigation of the actuator performance, measured in terms of its ability to reduce the pipe diameter, at a sustained frequency of 1.5 Hz. Moreover, we investigate how the diameter contraction is affected by various design parameters as well as actuation frequencies up to 4 Hz. We manage to make the NiTi wire work at 3% in strain, cyclically providing the designed pipe wall displacement. The actuator performance is found to decay approximately linearly with actuation frequencies up to 4 Hz. Also, the interface between the wire and the aluminum parts is found to be essential in defining the functional performance of the actuator. (paper)

  11. A Uniform Energy Consumption Algorithm for Wireless Sensor and Actuator Networks Based on Dynamic Polling Point Selection

    Science.gov (United States)

    Li, Shuo; Peng, Jun; Liu, Weirong; Zhu, Zhengfa; Lin, Kuo-Chi

    2014-01-01

    Recent research has indicated that using the mobility of the actuator in wireless sensor and actuator networks (WSANs) to achieve mobile data collection can greatly increase the sensor network lifetime. However, mobile data collection may result in unacceptable collection delays in the network if the path of the actuator is too long. Because real-time network applications require meeting data collection delay constraints, planning the path of the actuator is a very important issue to balance the prolongation of the network lifetime and the reduction of the data collection delay. In this paper, a multi-hop routing mobile data collection algorithm is proposed based on dynamic polling point selection with delay constraints to address this issue. The algorithm can actively update the selection of the actuator's polling points according to the sensor nodes' residual energies and their locations while also considering the collection delay constraint. It also dynamically constructs the multi-hop routing trees rooted by these polling points to balance the sensor node energy consumption and the extension of the network lifetime. The effectiveness of the algorithm is validated by simulation. PMID:24451455

  12. Laminated chemical and physical micro-jet actuators based on conductive media

    Science.gov (United States)

    Gadiraju, Priya D.

    2008-04-01

    This dissertation presents the development of electrically-powered, lamination-based microactuators for the realization of large arrays of high impulse and short duration micro-jets with potential applications in the field of micro-electro-mechanical systems (MEMS). Microactuators offer unique control opportunities by converting the input electrical or chemical energy stored in a propellant into useful mechanical energy. This small and precise control obtained can potentially be applied towards aerodynamic control and transdermal drug delivery applications. This thesis work discusses the feasibility of using microactuators for two such applications: Control of the motion of a spinning projectile by utilizing the chemically-driven microjets ejected from the actuators, and enhancement of the permeability properties of skin by selectively ablating the stratum corneum layer of skin using the physical microjets ejected from the actuators. This enhanced permeability of skin can later be used for the delivery of high molecular weight drugs for transdermal drug delivery. The development of electrically powered microactuators starts by fabricating an array of radially firing microactuators using lamination-based microfabrication techniques that potentially enable batch fabrication at low cost. The microactuators of this thesis consist of three main parts: a micro chamber in which the propellant is stored; two electrode structures through which electrical energy is supplied to the propellant; and a micro nozzle through which the propellant or released gases from the propellant are expanded as a jet. Once the actuators are fabricated, they are integrated with MEMS-process-compatible propellants and optimized so as to produce instantaneous ignition of the propellant. This instantaneous ignition is achieved either by making the propellant itself conductive, thus, passing an electric current directly through the propellant; or by discharging an arc across the propellant by

  13. Reconfigurable multi-DSP parallel computing architecture based on DSM%基于DSM的可重构多DSP并行处理架构

    Institute of Scientific and Technical Information of China (English)

    程鑫; 吴华春

    2012-01-01

    提出一种基于DSM的可在线重构多DSP并行处理架构,采用基于自定义内部总线的信息传递服务,在分布式物理内存上实现了统一编址的共享内存模型,减小了DSP之间的数据传递开销;设计基于VME总线的在线重构来实现针对消息传递服务的重定义,增强了并行计算架构的通用性.实验表明,采用此DSM能减小了并行DSP对共享数据同步访问开销,满足多轴精密同步运动控制系统需求.%A design of reconfigurable multi-digital signal processor (DSP) parallel computing architecture based on distributed shared memory (DSM) was proposed. A message-passing communication based on the user-defined internal bus (IB) was designed to implement a shared memory model on physically distributed memory, which decreased the data transmission overhead. Online reconfiguration mechanism was designed to implement message-passing communication reconfiguration, which in-creasd the universality of parallel architecture. The experiment shows that adopting the DSM introduced can reduce simultaneous access overhead to shared data, which satisfies the requirements of ultra-precise multi-axis motion control system.

  14. Model-Based Evolution of a Fast Hybrid Fuzzy Adaptive Controller for a Pneumatic Muscle Actuator

    Directory of Open Access Journals (Sweden)

    Alexander Hošovský

    2012-07-01

    Full Text Available Pneumatic artificial muscle-based robotic systems usually necessitate the use of various nonlinear control techniques in order to improve their performance. Their robustness to parameter variation, which is generally difficult to predict, should also be tested. Here a fast hybrid adaptive control is proposed, where a conventional PD controller is placed into the feedforward branch and a fuzzy controller is placed into the adaptation branch. The fuzzy controller compensates for the actions of the PD controller under conditions of inertia moment variation. The fuzzy controller of Takagi-Sugeno type is evolved through a genetic algorithm using the dynamic model of a pneumatic muscle actuator. The results confirm the capability of the designed system to provide robust performance under the conditions of varying inertia.

  15. Parameter identification based on modified simulated annealing differential evolution algorithm for giant magnetostrictive actuator

    Science.gov (United States)

    Gao, Xiaohui; Liu, Yongguang

    2018-01-01

    There is a serious nonlinear relationship between input and output in the giant magnetostrictive actuator (GMA) and how to establish mathematical model and identify its parameters is very important to study characteristics and improve control accuracy. The current-displacement model is firstly built based on Jiles-Atherton (J-A) model theory, Ampere loop theorem and stress-magnetism coupling model. And then laws between unknown parameters and hysteresis loops are studied to determine the data-taking scope. The modified simulated annealing differential evolution algorithm (MSADEA) is proposed by taking full advantage of differential evolution algorithm's fast convergence and simulated annealing algorithm's jumping property to enhance the convergence speed and performance. Simulation and experiment results shows that this algorithm is not only simple and efficient, but also has fast convergence speed and high identification accuracy.

  16. Wind Turbine Rotor Simulation via CFD Based Actuator Disc Technique Compared to Detailed Measurement

    Directory of Open Access Journals (Sweden)

    Esmail Mahmoodi

    2015-10-01

    Full Text Available In this paper, a generalized Actuator Disc (AD is used to model the wind turbine rotor of the MEXICO experiment, a collaborative European wind turbine project. The AD model as a combination of CFD technique and User Defined Functions codes (UDF, so-called UDF/AD model is used to simulate loads and performance of the rotor in three different wind speed tests. Distributed force on the blade, thrust and power production of the rotor as important designing parameters of wind turbine rotors are focused to model. A developed Blade Element Momentum (BEM theory as a code based numerical technique as well as a full rotor simulation both from the literature are included into the results to compare and discuss. The output of all techniques is compared to detailed measurements for validation, which led us to final conclusions.

  17. Flytrap-inspired robot using structurally integrated actuation based on bistability and a developable surface.

    Science.gov (United States)

    Kim, Seung-Won; Koh, Je-Sung; Lee, Jong-Gu; Ryu, Junghyun; Cho, Maenghyo; Cho, Kyu-Jin

    2014-09-01

    The Venus flytrap uses bistability, the structural characteristic of its leaf, to actuate the leaf's rapid closing motion for catching its prey. This paper presents a flytrap-inspired robot and novel actuation mechanism that exploits the structural characteristics of this structure and a developable surface. We focus on the concept of exploiting structural characteristics for actuation. Using shape memory alloy (SMA), the robot actuates artificial leaves made from asymmetrically laminated carbon fiber reinforced prepregs. We exploit two distinct structural characteristics of the leaves. First, the bistability acts as an implicit actuator enabling rapid morphing motion. Second, the developable surface has a kinematic constraint that constrains the curvature of the artificial leaf. Due to this constraint, the curved artificial leaf can be unbent by bending the straight edge orthogonal to the curve. The bending propagates from one edge to the entire surface and eventually generates an overall shape change. The curvature change of the artificial leaf is 18 m(-1) within 100 ms when closing. Experiments show that these actuation mechanisms facilitate the generation of a rapid and large morphing motion of the flytrap robot by one-way actuation of the SMA actuators at a local position.

  18. Piezoelectric-hydraulic pump based band brake actuation system for automotive transmission control

    Science.gov (United States)

    Kim, Gi-Woo; Wang, K. W.

    2007-04-01

    The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic pump to the input of the band brake. Compared with the current systems, this new actuator features much simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated using experimental data. Performance tests on the hardware and system simulations utilizing the validated model are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for AT shift control.

  19. Flytrap-inspired robot using structurally integrated actuation based on bistability and a developable surface

    International Nuclear Information System (INIS)

    Kim, Seung-Won; Koh, Je-Sung; Cho, Kyu-Jin; Lee, Jong-Gu; Ryu, Junghyun; Cho, Maenghyo

    2014-01-01

    The Venus flytrap uses bistability, the structural characteristic of its leaf, to actuate the leaf's rapid closing motion for catching its prey. This paper presents a flytrap-inspired robot and novel actuation mechanism that exploits the structural characteristics of this structure and a developable surface. We focus on the concept of exploiting structural characteristics for actuation. Using shape memory alloy (SMA), the robot actuates artificial leaves made from asymmetrically laminated carbon fiber reinforced prepregs. We exploit two distinct structural characteristics of the leaves. First, the bistability acts as an implicit actuator enabling rapid morphing motion. Second, the developable surface has a kinematic constraint that constrains the curvature of the artificial leaf. Due to this constraint, the curved artificial leaf can be unbent by bending the straight edge orthogonal to the curve. The bending propagates from one edge to the entire surface and eventually generates an overall shape change. The curvature change of the artificial leaf is 18 m −1  within 100 ms when closing. Experiments show that these actuation mechanisms facilitate the generation of a rapid and large morphing motion of the flytrap robot by one-way actuation of the SMA actuators at a local position. (paper)

  20. Value Assessment of Distribution Network Reconfiguration: A Danish Case Study

    DEFF Research Database (Denmark)

    Vaskantiras, Georgios; You, Shi

    2016-01-01

    . This paper presents a case study-based analysis to explore the potential value of reconfiguration in detail. The study is performed using a 10kV distribution grid of Denmark, while reconfiguration is applied to minimize the energy losses under both normal and post-fault conditions. The results show......Distribution network reconfiguration is a mechanism that can improve the distribution system performance from multiple perspectives. In the context of smart grid wherein the degrees of automation and intelligence are high, the potential value of network reconfiguration can be significant...

  1. Reconfigurable topological photonic crystal

    Science.gov (United States)

    Shalaev, Mikhail I.; Desnavi, Sameerah; Walasik, Wiktor; Litchinitser, Natalia M.

    2018-02-01

    Topological insulators are materials that conduct on the surface and insulate in their interior due to non-trivial topology of the band structure. The edge states on the interface between topological (non-trivial) and conventional (trivial) insulators are topologically protected from scattering due to structural defects and disorders. Recently, it was shown that photonic crystals (PCs) can serve as a platform for realizing a scatter-free propagation of light waves. In conventional PCs, imperfections, structural disorders, and surface roughness lead to significant losses. The breakthrough in overcoming these problems is likely to come from the synergy of the topological PCs and silicon-based photonics technology that enables high integration density, lossless propagation, and immunity to fabrication imperfections. For many applications, reconfigurability and capability to control the propagation of these non-trivial photonic edge states is essential. One way to facilitate such dynamic control is to use liquid crystals (LCs), which allow to modify the refractive index with external electric field. Here, we demonstrate dynamic control of topological edge states by modifying the refractive index of a LC background medium. Background index is changed depending on the orientation of a LC, while preserving the topology of the system. This results in a change of the spectral position of the photonic bandgap and the topological edge states. The proposed concept might be implemented using conventional semiconductor technology, and can be used for robust energy transport in integrated photonic devices, all-optical circuity, and optical communication systems.

  2. Enabling Self-Organization in Embedded Systems with Reconfigurable Hardware

    Directory of Open Access Journals (Sweden)

    Christophe Bobda

    2009-01-01

    Full Text Available We present a methodology based on self-organization to manage resources in networked embedded systems based on reconfigurable hardware. Two points are detailed in this paper, the monitoring system used to analyse the system and the Local Marketplaces Global Symbiosis (LMGS concept defined for self-organization of dynamically reconfigurable nodes.

  3. Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions

    Science.gov (United States)

    Kim, Gi-Woo; Wang, K. W.

    2009-08-01

    In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT 1\\to 2 up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements.

  4. Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions

    International Nuclear Information System (INIS)

    Kim, Gi-Woo; Wang, K W

    2009-01-01

    In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT 1→2 up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements

  5. Recurrent-neural-network-based identification of a cascade hydraulic actuator for closed-loop automotive power transmission control

    International Nuclear Information System (INIS)

    You, Seung Han; Hahn, Jin Oh

    2012-01-01

    By virtue of its ease of operation compared with its conventional manual counterpart, automatic transmissions are commonly used as automotive power transmission control system in today's passenger cars. In accordance with this trend, research efforts on closed-loop automatic transmission controls have been extensively carried out to improve ride quality and fuel economy. State-of-the-art power transmission control algorithms may have limitations in performance because they rely on the steady-state characteristics of the hydraulic actuator rather than fully exploit its dynamic characteristics. Since the ultimate viability of closed-loop power transmission control is dominated by precise pressure control at the level of hydraulic actuator, closed-loop control can potentially attain superior efficacy in case the hydraulic actuator can be easily incorporated into model-based observer/controller design. In this paper, we propose to use a recurrent neural network (RNN) to establish a nonlinear empirical model of a cascade hydraulic actuator in a passenger car automatic transmission, which has potential to be easily incorporated in designing observers and controllers. Experimental analysis is performed to grasp key system characteristics, based on which a nonlinear system identification procedure is carried out. Extensive experimental validation of the established model suggests that it has superb one-step-ahead prediction capability over appropriate frequency range, making it an attractive approach for model-based observer/controller design applications in automotive systems

  6. Linear Extended State Observer-Based Motion Synchronization Control for Hybrid Actuation System of More Electric Aircraft

    Directory of Open Access Journals (Sweden)

    Xingjian Wang

    2017-10-01

    Full Text Available Moving towards the more electric aircraft (MEA, a hybrid actuator configuration provides an opportunity to introduce electromechanical actuator (EMA into primary flight control. In the hybrid actuation system (HAS, an electro-hydraulic servo actuator (EHSA and an EMA operate on the same control surface. In order to solve force fighting problem in HAS, this paper proposes a novel linear extended state observer (LESO-based motion synchronization control method. To cope with the problem of unavailability of the state signals required by the motion synchronization controller, LESO is designed for EHSA and EMA to observe the state variables. Based on the observed states of LESO, motion synchronization controllers could enable EHSA and EMA to simultaneously track the desired motion trajectories. Additionally, nonlinearities, uncertainties and unknown disturbances as well as the coupling term between EHSA and EMA can be estimated and compensated by using the extended state of the proposed LESO. Finally, comparative simulation results indicate that the proposed LESO-based motion synchronization controller could reduce significant force fighting between EHSA and EMA.

  7. Linear Extended State Observer-Based Motion Synchronization Control for Hybrid Actuation System of More Electric Aircraft

    Science.gov (United States)

    Liao, Rui; Shi, Cun; Wang, Shaoping

    2017-01-01

    Moving towards the more electric aircraft (MEA), a hybrid actuator configuration provides an opportunity to introduce electromechanical actuator (EMA) into primary flight control. In the hybrid actuation system (HAS), an electro-hydraulic servo actuator (EHSA) and an EMA operate on the same control surface. In order to solve force fighting problem in HAS, this paper proposes a novel linear extended state observer (LESO)-based motion synchronization control method. To cope with the problem of unavailability of the state signals required by the motion synchronization controller, LESO is designed for EHSA and EMA to observe the state variables. Based on the observed states of LESO, motion synchronization controllers could enable EHSA and EMA to simultaneously track the desired motion trajectories. Additionally, nonlinearities, uncertainties and unknown disturbances as well as the coupling term between EHSA and EMA can be estimated and compensated by using the extended state of the proposed LESO. Finally, comparative simulation results indicate that the proposed LESO-based motion synchronization controller could reduce significant force fighting between EHSA and EMA. PMID:29068392

  8. A Novel Docking System for Modular Self-Reconfigurable Robots

    Directory of Open Access Journals (Sweden)

    Tan Zhang

    2017-10-01

    Full Text Available Existing self-reconfigurable robots achieve connections and disconnections by a separate drive of the docking system. In this paper, we present a new docking system with which the connections and disconnections are driven by locomotion actuators, without the need for a separate drive, which reduces the weight and the complexity of the modules. This self-reconfigurable robot consists of two types of fundamental modules, i.e., active and passive modules. By the docking system, two types of connections are formed with the fundamental modules, and the docking and undocking actions are achieved through simple control with less sensory feedback. This paper describes the design of the robotic modules, the docking system, the docking process, and the docking force analysis. An experiment is performed to demonstrate the self-reconfigurable robot with the docking system.

  9. Realization of the FPGA-based reconfigurable computing environment by the example of morphological processing of a grayscale image

    Science.gov (United States)

    Shatravin, V.; Shashev, D. V.

    2018-05-01

    Currently, robots are increasingly being used in every industry. One of the most high-tech areas is creation of completely autonomous robotic devices including vehicles. The results of various global research prove the efficiency of vision systems in autonomous robotic devices. However, the use of these systems is limited because of the computational and energy resources available in the robot device. The paper describes the results of applying the original approach for image processing on reconfigurable computing environments by the example of morphological operations over grayscale images. This approach is prospective for realizing complex image processing algorithms and real-time image analysis in autonomous robotic devices.

  10. Particle swarm optimization based solar PV array reconfiguration of the maximum power extraction under partial shading conditions

    DEFF Research Database (Denmark)

    Babu, Thanikanti Sudhakar; Ram, J. Prasanth; Dragicevic, Tomislav

    2018-01-01

    For large photovoltaic power generation plants, number of panels are interconnected in series and parallel to form a photovoltaic (PV) array. In this configuration, partial shade will result in decrease in power output and introduce multiple peaks in the P–V curve. As a consequence, the modules...... in the array will deliver different row currents. Therefore, to maximize the power extraction from PV array, the panels need to be reconfigured for row current difference minimization. Row current minimization via Su Do Ku game theory do physical relocation of panels may cause laborious work and lengthy...

  11. Hysteresis modeling of magnetic shape memory alloy actuator based on Krasnosel'skii-Pokrovskii model.

    Science.gov (United States)

    Zhou, Miaolei; Wang, Shoubin; Gao, Wei

    2013-01-01

    As a new type of intelligent material, magnetically shape memory alloy (MSMA) has a good performance in its applications in the actuator manufacturing. Compared with traditional actuators, MSMA actuator has the advantages as fast response and large deformation; however, the hysteresis nonlinearity of the MSMA actuator restricts its further improving of control precision. In this paper, an improved Krasnosel'skii-Pokrovskii (KP) model is used to establish the hysteresis model of MSMA actuator. To identify the weighting parameters of the KP operators, an improved gradient correction algorithm and a variable step-size recursive least square estimation algorithm are proposed in this paper. In order to demonstrate the validity of the proposed modeling approach, simulation experiments are performed, simulations with improved gradient correction algorithm and variable step-size recursive least square estimation algorithm are studied, respectively. Simulation results of both identification algorithms demonstrate that the proposed modeling approach in this paper can establish an effective and accurate hysteresis model for MSMA actuator, and it provides a foundation for improving the control precision of MSMA actuator.

  12. A multi-segment soft actuator for biomedical applications based on IPMCs

    Science.gov (United States)

    Zhao, Dongxu; Wang, Yanjie; Liu, Jiayu; Luo, Meng; Li, Dichen; Chen, Hualing

    2015-04-01

    With rapid progress of biomedical devices towards miniaturization, flexibility, multifunction and low cost, the restrictions of traditional mechanical structures become particularly apparent, while soft materials become research focus in broad fields. As one of the most attractive soft materials, Ionic Polymer-Metal Composite (IPMC) is widely used as artificial muscles and actuators, with the advantages of low driving-voltage, high efficiency of electromechanical transduction and functional stabilization. In this paper, a new intuitive control method was presented to achieve the omnidirectional bending movements and was applied on a representative actuation structure of a multi-degree-offreedom soft actuator composed of two segments bar-shaped IPMC with a square cross section. Firstly, the bar-shaped IPMCs were fabricated by the solution casting method, reducing plating, autocatalytic plating method and cut into shapes successively. The connectors of the multi-segment IPMC actuator were fabricated by 3D printing. Then, a new control method was introduced to realize the intuitive mapping relationship between the actuator and the joystick manipulator. The control circuit was designed and tested. Finally, the multi-degree-of-freedom actuator of 2 segments bar-shaped IPMCs was implemented and omnidirectional bending movements were achieved, which could be a promising actuator for biomedical applications, such as endoscope, catheterism, laparoscopy and the surgical resection of tumors.

  13. Hysteresis Modeling of Magnetic Shape Memory Alloy Actuator Based on Krasnosel'skii-Pokrovskii Model

    Directory of Open Access Journals (Sweden)

    Miaolei Zhou

    2013-01-01

    Full Text Available As a new type of intelligent material, magnetically shape memory alloy (MSMA has a good performance in its applications in the actuator manufacturing. Compared with traditional actuators, MSMA actuator has the advantages as fast response and large deformation; however, the hysteresis nonlinearity of the MSMA actuator restricts its further improving of control precision. In this paper, an improved Krasnosel'skii-Pokrovskii (KP model is used to establish the hysteresis model of MSMA actuator. To identify the weighting parameters of the KP operators, an improved gradient correction algorithm and a variable step-size recursive least square estimation algorithm are proposed in this paper. In order to demonstrate the validity of the proposed modeling approach, simulation experiments are performed, simulations with improved gradient correction algorithm and variable step-size recursive least square estimation algorithm are studied, respectively. Simulation results of both identification algorithms demonstrate that the proposed modeling approach in this paper can establish an effective and accurate hysteresis model for MSMA actuator, and it provides a foundation for improving the control precision of MSMA actuator.

  14. Reconfiguring trade mark law

    DEFF Research Database (Denmark)

    Elsmore, Matthew James

    2013-01-01

    -border setting, with a particular focus on small business and consumers. The article's overall message is to call for a rethink of received wisdom suggesting that trade marks are effective trade-enabling devices. The case is made for reassessing how we think about European trade mark law.......First, this article argues that trade mark law should be approached in a supplementary way, called reconfiguration. Second, the article investigates such a reconfiguration of trade mark law by exploring the interplay of trade marks and service transactions in the Single Market, in the cross...

  15. Magnetic Actuation of Biological Systems

    Science.gov (United States)

    Lauback, Stephanie D.

    Central to the advancement of many biomedical and nanotechnology capabilities is the capacity to precisely control the motion of micro and nanostructures. These applications range from single molecule experiments to cell isolation and separation, to drug delivery and nanomachine manipulation. This dissertation focuses on actuation of biological micro- and nano-entities through the use of weak external magnetic fields, superparamagnetic beads, and ferromagnetic thin films. The magnetic platform presents an excellent method for actuation of biological systems due to its ability to directly control the motion of an array of micro and nanostructures in real-time with calibrated picoNewton forces. The energy landscape of two ferromagnetic thin film patterns (disks and zigzag wires) is experimentally explored and compared to corresponding theoretical models to quantify the applied forces and trajectories of superparamagnetic beads due to the magnetic traps. A magnetic method to directly actuate DNA nanomachines in real-time with nanometer resolution and sub-second response times using micromagnetic control was implemented through the use of stiff DNA micro-levers which bridged the large length scale mismatch between the micro-actuator and the nanomachine. Compared to current alternative methods which are limited in the actuation speeds and the number of reconfiguration states of DNA constructs, this magnetic approach enables fast actuation (˜ milliseconds) and reconfigurable conformations achieved through a continuous range of finely tuned steps. The system was initially tested through actuation of the stiff arm tethered to the surface, and two prototype DNA nanomachines (rotor and hinge) were successfully actuated using the stiff mechanical lever. These results open new possibilities in the development of functional robotic systems at the molecular scale. In exploiting the use of DNA stiff levers, a new technique was also developed to investigate the emergence of the

  16. Mobile Autonomous Reconfigurable System

    Directory of Open Access Journals (Sweden)

    Pavliuk N.A.

    2018-04-01

    Full Text Available The object of this study is a multifunctional modular robot able to assemble independently in a given configuration and responsively change it in the process of operation depending on the current task. In this work we aim at developing and examining unified modules for a modular robot, which can both perform autonomous movement and form a complex structure by connecting to other modules. The existing solutions in the field of modular robotics were reviewed and classified by power supply, the ways of interconnection, the ways of movement and the possibility of independent movement of separate modules. Basing on the analysis of the shortcomings of existing analogues, we have developed a module of mobile autonomous reconfigurable system, including a base unit, a set of magneto-mechanical connectors and two motor wheels. The basic kinematic scheme of the modular robot, the features of a single module, as well as the modular structure formed by an array of similar modules were described. Two schemes for placing sets of magneto-mechanical connectors in the basic module have been proposed. We described the principle of operation of a magneto-mechanical connector based on redirection of the magnetic flux of a permanent magnet. This solution simplifies the system for controlling a mechanism of connection with other modules, increases energy efficiency and a battery life of the module. Since the energy is required only at the moment of switching the operating modes of the connector, there is no need to power constantly the connector mechanism to maintain the coupling mode.

  17. On the Feasibility and Limitations of Just-in-Time Instruction Set Extension for FPGA-Based Reconfigurable Processors

    Directory of Open Access Journals (Sweden)

    Mariusz Grad

    2012-01-01

    Full Text Available Reconfigurable instruction set processors provide the possibility of tailor the instruction set of a CPU to a particular application. While this customization process could be performed during runtime in order to adapt the CPU to the currently executed workload, this use case has been hardly investigated. In this paper, we study the feasibility of moving the customization process to runtime and evaluate the relation of the expected speedups and the associated overheads. To this end, we present a tool flow that is tailored to the requirements of this just-in-time ASIP specialization scenario. We evaluate our methods by targeting our previously introduced Woolcano reconfigurable ASIP architecture for a set of applications from the SPEC2006, SPEC2000, MiBench, and SciMark2 benchmark suites. Our results show that just-in-time ASIP specialization is promising for embedded computing applications, where average speedups of 5x can be achieved by spending 50 minutes for custom instruction identification and hardware generation. These overheads will be compensated if the applications execute for more than 2 hours. For the scientific computing benchmarks, the achievable speedup is only 1.2x, which requires significant execution times in the order of days to amortize the overheads.

  18. Inflatable actuators: an attempt for a common approach based on Treloar’s rubber elasticity theory

    Science.gov (United States)

    Tondu, Bertrand

    2018-01-01

    Inflatable actuators are defined as pressure hyperelastic vessels whose expansion is constrained for generating either movements in extension, or typical contractile movements of artificial muscles. By using Treloar’s theory of rubber elasticity, applied to thin-walled pressure vessels, we propose to determine in which conditions they can be considered as stable open-loop positioning actuators. Antagonism can be viewed as an extension of this open-loop stability principle applicable to artificial muscles as to extensible actuators. We especially show its relevance for multiple chambers pressurized cylinders and how Treloar’s theory can help to model their bending in a readable and relevant formal way. We also try to justify why we think that antagonism applied to extensible actuators can actually appear as the best way for designing miniaturized multiple degrees of freedom rubber made microactuators if, however, only a limited power is required.

  19. Capacitive sensing of droplets for microfluidic devices based on thermocapillary actuation

    NARCIS (Netherlands)

    Chen, J.-Z.; Darhuber, A.A.; Troian, S.M.; Wagner, S.

    2004-01-01

    The design and performance of a miniaturized coplanar capacitive sensor is presented whose electrode arrays can also function as resistive microheaters for thermocapillary actuation of liquid films and droplets. Optimal compromise between large capacitive signal and high spatial resolution is

  20. Synthetic Jet Actuator-Based Aircraft Tracking Using a Continuous Robust Nonlinear Control Strategy

    Directory of Open Access Journals (Sweden)

    N. Ramos-Pedroza

    2017-01-01

    Full Text Available A robust nonlinear control law that achieves trajectory tracking control for unmanned aerial vehicles (UAVs equipped with synthetic jet actuators (SJAs is presented in this paper. A key challenge in the control design is that the dynamic characteristics of SJAs are nonlinear and contain parametric uncertainty. The challenge resulting from the uncertain SJA actuator parameters is mitigated via innovative algebraic manipulation in the tracking error system derivation along with a robust nonlinear control law employing constant SJA parameter estimates. A key contribution of the paper is a rigorous analysis of the range of SJA actuator parameter uncertainty within which asymptotic UAV trajectory tracking can be achieved. A rigorous stability analysis is carried out to prove semiglobal asymptotic trajectory tracking. Detailed simulation results are included to illustrate the effectiveness of the proposed control law in the presence of wind gusts and varying levels of SJA actuator parameter uncertainty.

  1. SMA spring-based artificial muscle actuated by hot and cool water using faucet-like valve

    Science.gov (United States)

    Park, Cheol Hoon; Son, Young Su

    2017-04-01

    An artificial muscle for a human arm-like manipulator with high strain and high power density are under development, and an SMA(Shape memory alloy) spring is a good actuator for this application. In this study, an artificial muscle composed of a silicon tube and a bundle of SMA(Shape memory alloy) springs is evaluated. A bundle of SMA springs consists of five SMA springs which are fabricated by using SMA wires with a diameter of 0.5 mm, and hot and cool water actuates it by heating and cooling SMA springs. A faucet-like valve was also developed to mix hot water and cool water and control the water temperature. The mass of silicon tube and a bundle of SMA springs is only 3.3 g and 2.25 g, respectively, and the total mass of artificial muscle is 5.55 g. It showed good actuating performance for a load with a mass of 2.3 kg and the power density was more than 800 W/kg for continuous valve switching with a cycle of 0.6 s. The faucet-like valve can switch a water output from hot water to cold water within 0.3s, and the artificial muscle is actuated well in response to the valve position and speed. It is also presented that the temperature of the mixed water can be controlled depending on the valve position, and the displacement of the artificial muscle can be controlled well by the mixed water. Based on these results, SMA spring-based artificial muscle actuated by hot and cool water could be applicable to the human arm-like robot manipulators.

  2. Modeling and control of precision actuators

    CERN Document Server

    Kiong, Tan Kok

    2013-01-01

    IntroductionGrowing Interest in Precise ActuatorsTypes of Precise ActuatorsApplications of Precise ActuatorsNonlinear Dynamics and ModelingHysteresisCreepFrictionForce RipplesIdentification and Compensation of Preisach Hysteresis in Piezoelectric ActuatorsSVD-Based Identification and Compensation of Preisach HysteresisHigh-Bandwidth Identification and Compensation of Hysteretic Dynamics in Piezoelectric ActuatorsConcluding RemarksIdentification and Compensation of Frict

  3. Knowledge-based Adaptive Tracking Control of Electro-hydraulic Actuator Systems

    DEFF Research Database (Denmark)

    Hansen, Poul Erik

    1997-01-01

    The paper deal with intelligent motion control and electro-hydraulic actuator systems for multiaxis machynes and robots.The research results are from the IMCIA research Programme supported by the Danish Technical Research Council, STVF.......The paper deal with intelligent motion control and electro-hydraulic actuator systems for multiaxis machynes and robots.The research results are from the IMCIA research Programme supported by the Danish Technical Research Council, STVF....

  4. Reconfigurable Mobile Multimedia

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Bos, M.; Havinga, Paul J.M.; Smit, Jaap

    1999-01-01

    This paper discusses reconfigurability issues in lowpower hand-held multimedia systems, with particular emphasis on energy conservation. We claim that a radical new approach has to be taken in order to fulfill the requirements - in terms of processing power and energy consumption - of future mobile

  5. Reconfigurable layout problem

    NARCIS (Netherlands)

    Meng, G.; Heragu, S.S.; Heragu, S.S.; Zijm, Willem H.M.

    2004-01-01

    This paper addresses the reconfigurable layout problem, which differs from traditional, robust and dynamic layout problems mainly in two aspects: first, it assumes that production data are available only for the current and upcoming production period. Second, it considers queuing performance

  6. Finite element analysis of electroactive polymer and magnetoactive elastomer based actuation for origami folding

    Science.gov (United States)

    Zhang, Wei; Ahmed, Saad; Masters, Sarah; Ounaies, Zoubeida; Frecker, Mary

    2017-10-01

    The incorporation of smart materials such as electroactive polymers and magnetoactive elastomers in origami structures can result in active folding using external electric and magnetic stimuli, showing promise in many origami-inspired engineering applications. In this study, 3D finite element analysis (FEA) models are developed using COMSOL Multiphysics software for three configurations that incorporate a combination of active and passive material layers, namely: (1) a single-notch unimorph folding configuration actuated using only external electric field, (2) a double-notch unimorph folding configuration actuated using only external electric field, and (3) a bifold configuration which is actuated using multi-field (electric and magnetic) stimuli. The objectives of the study are to verify the effectiveness of the FEA models to simulate folding behavior and to investigate the influence of geometric parameters on folding quality. Equivalent mechanical pressure and surface stress are used as external loads in the FEA to simulate electric and magnetic fields, respectively. Compared quantitatively with experimental data, FEA captured the folding performance of electric actuation well for notched configurations and magnetic actuation for a bifold structure, but underestimated electric actuation for the bifold structure. By investigating the impact of geometric parameters and locations to place smart materials, FEA can be used in design, avoiding trial-and-error iterations of experiments.

  7. Design of a Telescopic Linear Actuator Based on Hollow Shape Memory Springs

    Science.gov (United States)

    Spaggiari, Andrea; Spinella, Igor; Dragoni, Eugenio

    2011-07-01

    Shape memory alloys (SMAs) are smart materials exploited in many applications to build actuators with high power to mass ratio. Typical SMA drawbacks are: wires show poor stroke and excessive length, helical springs have limited mechanical bandwidth and high power consumption. This study is focused on the design of a large-scale linear SMA actuator conceived to maximize the stroke while limiting the overall size and the electric consumption. This result is achieved by adopting for the actuator a telescopic multi-stage architecture and using SMA helical springs with hollow cross section to power the stages. The hollow geometry leads to reduced axial size and mass of the actuator and to enhanced working frequency while the telescopic design confers to the actuator an indexable motion, with a number of different displacements being achieved through simple on-off control strategies. An analytical thermo-electro-mechanical model is developed to optimize the device. Output stroke and force are maximized while total size and power consumption are simultaneously minimized. Finally, the optimized actuator, showing good performance from all these points of view, is designed in detail.

  8. A novel vibration assisted polishing device based on the flexural mechanism driven by the piezoelectric actuators

    Directory of Open Access Journals (Sweden)

    Guilian Wang

    2018-01-01

    Full Text Available The vibration assisted polishing has widely application fields because of higher machining frequency and better polishing quality, especially the polishing with the non-resonant mode that is regarded as a kind of promising polishing method. This paper reports a novel vibration assisted polishing device, consisting of the flexible hinge mechanism driven by the piezoelectric actuators, which is suitable for polishing planes or curve surfaces with slow curvature. Firstly, the generation methods of vibration trajectory are investigated for the same frequency and different frequency signals’ inputs, respectively, and then the types of elliptic and Lissajous’s vibration trajectories are generated respectively. Secondly, a flexural mechanism consisting of the right circular flexible hinges and the leaf springs is developed to produce two-dimensional vibration trajectory. Statics and dynamics investigating of this flexible mechanism are finished in detail. The analytical models about input and output compliances of the flexural mechanism are established according to the matrix-based compliance modeling, and the dynamic model of the flexural mechanism based on the Euler-Lagrange equation is also presented. The finite element model of the flexural mechanism was established to carry out the numerical simulation in order to testify the rationality of device design. Finally, the polishing experiment is carried out to prove the effectiveness of the vibration device. The experimental results show that this novel vibration assisted polishing device developed in this study can remove more effectively the cutting marks left by last process and obviously reduce the workpiece surface roughness.

  9. Design, fabrication and actuation of a MEMS-based image stabilizer for photographic cell phone applications

    International Nuclear Information System (INIS)

    Chiou, Jin-Chern; Hung, Chen-Chun; Lin, Chun-Ying

    2010-01-01

    This work presents a MEMS-based image stabilizer applied for anti-shaking function in photographic cell phones. The proposed stabilizer is designed as a two-axis decoupling XY stage 1.4 × 1.4 × 0.1 mm 3 in size, and adequately strong to suspend an image sensor for anti-shaking photographic function. This stabilizer is fabricated by complex fabrication processes, including inductively coupled plasma (ICP) processes and flip-chip bonding technique. Based on the special designs of a hollow handle layer and a corresponding wire-bonding assisted holder, electrical signals of the suspended image sensor can be successfully sent out with 32 signal springs without incurring damage during wire-bonding packaging. The longest calculated traveling distance of the stabilizer is 25 µm which is sufficient to resolve the anti-shaking problem in a three-megapixel image sensor. Accordingly, the applied voltage for the 25 µm moving distance is 38 V. Moreover, the resonant frequency of the actuating device with the image sensor is 1.123 kHz.

  10. Reconfigurable virtual electrowetting channels.

    Science.gov (United States)

    Banerjee, Ananda; Kreit, Eric; Liu, Yuguang; Heikenfeld, Jason; Papautsky, Ian

    2012-02-21

    Lab-on-a-chip systems rely on several microfluidic paradigms. The first uses a fixed layout of continuous microfluidic channels. Such lab-on-a-chip systems are almost always application specific and far from a true "laboratory." The second involves electrowetting droplet movement (digital microfluidics), and allows two-dimensional computer control of fluidic transport and mixing. The merging of the two paradigms in the form of programmable electrowetting channels takes advantage of both the "continuous" functionality of rigid channels based on which a large number of applications have been developed to date and the "programmable" functionality of digital microfluidics that permits electrical control of on-chip functions. In this work, we demonstrate for the first time programmable formation of virtual microfluidic channels and their continuous operation with pressure driven flows using an electrowetting platform. Experimental, theoretical, and numerical analyses of virtual channel formation with biologically relevant electrolyte solutions and electrically-programmable reconfiguration are presented. We demonstrate that the "wall-less" virtual channels can be formed reliably and rapidly, with propagation rates of 3.5-3.8 mm s(-1). Pressure driven transport in these virtual channels at flow rates up to 100 μL min(-1) is achievable without distortion of the channel shape. We further demonstrate that these virtual channels can be switched on-demand between multiple inputs and outputs. Ultimately, we envision a platform that would provide rapid prototyping of microfluidic concepts and would be capable of a vast library of functions and benefitting applications from clinical diagnostics in resource-limited environments to rapid system prototyping to high throughput pharmaceutical applications.

  11. Distinguishing Reconfiguration and Compound-cue Retrieval in Task Switching

    Directory of Open Access Journals (Sweden)

    Gordon D Logan

    2010-10-01

    Full Text Available Many researchers claim that task switching requires reconfiguration of the cognitive system. Others claim that task switching involves cue-based memory retrieval processes and not reconfiguration. We evaluate these competing claims by developing both reconfiguration and cue-based memory models in a common theoretical framework and by fitting the models to' target functions', which show how performance on individual target stimuli varies depending on the task subjects perform on the targets. Our analyses show that the process of compound-cue retrieval – using the task cue and the target as joint retrieval cues to select a response from memory – is sufficient to explain target functions for parity and magnitude judgments of digits and that reconfiguration does not seem to add anything to the explanation. We address the generality of this conclusion and speculate about the conditions under which reconfiguration may be necessary for task switching.

  12. Design Tools for Reconfigurable Hardware in Orbit (RHinO)

    Science.gov (United States)

    French, Mathew; Graham, Paul; Wirthlin, Michael; Larchev, Gregory; Bellows, Peter; Schott, Brian

    2004-01-01

    The Reconfigurable Hardware in Orbit (RHinO) project is focused on creating a set of design tools that facilitate and automate design techniques for reconfigurable computing in space, using SRAM-based field-programmable-gate-array (FPGA) technology. These tools leverage an established FPGA design environment and focus primarily on space effects mitigation and power optimization. The project is creating software to automatically test and evaluate the single-event-upsets (SEUs) sensitivities of an FPGA design and insert mitigation techniques. Extensions into the tool suite will also allow evolvable algorithm techniques to reconfigure around single-event-latchup (SEL) events. In the power domain, tools are being created for dynamic power visualiization and optimization. Thus, this technology seeks to enable the use of Reconfigurable Hardware in Orbit, via an integrated design tool-suite aiming to reduce risk, cost, and design time of multimission reconfigurable space processors using SRAM-based FPGAs.

  13. Graphene-Based Functional Architectures: Sheets Regulation and Macrostructure Construction toward Actuators and Power Generators.

    Science.gov (United States)

    Cheng, Huhu; Huang, Yaxin; Shi, Gaoquan; Jiang, Lan; Qu, Liangti

    2017-07-18

    Graphene, with large delocalized π electron cloud on a two-dimensional (2D) atom-thin plane, possesses excellent carrier mobility, large surface area, high light transparency, high mechanical strength, and superior flexibility. However, the lack of intrinsic band gap, poor dispersibility, and weak reactivity of graphene hinder its application scope. Heteroatom-doping regulation and surface modification of graphene can effectively reconstruct the sp 2 bonded carbon atoms and tailor the surface chemistry and interfacial interaction, while microstructure mediation on graphene can induce the special chemical and physical properties because of the quantum confinement, edge effect, and unusual mass transport process. Based on these regulations on graphene, series of methods and techniques are developed to couple the promising characters of graphene into the macroscopic architectures for potential and practical applications. In this Account, we present our effort on graphene regulation from chemical modification to microstructure control, from the morphology-designed macroassemblies to their applications in functional systems excluding the energy-storage devices. We first introduce the chemically regulative graphene with incorporated heteroatoms into the honeycomb lattice, which could open the intrinsic band gap and provide many active sites. Then the surface modification of graphene with functional components will improve dispersibility, prevent aggregation, and introduce new functions. On the other hand, microstructure mediation on graphene sheets (e.g., 0D quantum dots, 1D nanoribbons, and 2D nanomeshes) is demonstrated to induce special chemical and physical properties. Benefiting from the effective regulation on graphene sheets, diverse methods including dimension-confined strategy, filtration assembly, and hydrothermal treatment have been developed to assemble individual graphene sheets to macroscopic graphene fibers, films, and frameworks. These rationally

  14. Facilitating preemptive hardware system design using partial reconfiguration techniques.

    Science.gov (United States)

    Dondo Gazzano, Julio; Rincon, Fernando; Vaderrama, Carlos; Villanueva, Felix; Caba, Julian; Lopez, Juan Carlos

    2014-01-01

    In FPGA-based control system design, partial reconfiguration is especially well suited to implement preemptive systems. In real-time systems, the deadline for critical task can compel the preemption of noncritical one. Besides, an asynchronous event can demand immediate attention and, then, force launching a reconfiguration process for high-priority task implementation. If the asynchronous event is previously scheduled, an explicit activation of the reconfiguration process is performed. If the event cannot be previously programmed, such as in dynamically scheduled systems, an implicit activation to the reconfiguration process is demanded. This paper provides a hardware-based approach to explicit and implicit activation of the partial reconfiguration process in dynamically reconfigurable SoCs and includes all the necessary tasks to cope with this issue. Furthermore, the reconfiguration service introduced in this work allows remote invocation of the reconfiguration process and then the remote integration of off-chip components. A model that offers component location transparency is also presented to enhance and facilitate system integration.

  15. Experimental and Simulation-Based Investigation of Polycentric Motion of an Inherent Compliant Pneumatic Bending Actuator with Skewed Rotary Elastic Chambers

    Directory of Open Access Journals (Sweden)

    André Wilkening

    2017-01-01

    Full Text Available To offer a functionality that could not be found in traditional rigid robots, compliant actuators are in development worldwide for a variety of applications and especially for human–robot interaction. Pneumatic bending actuators are a special kind of such actuators. Due to the absence of fixed mechanical axes and their soft behavior, these actuators generally possess a polycentric motion ability. This can be very useful to provide an implicit self-alignment to human joint axes in exoskeleton-like rehabilitation devices. As a possible realization, a novel bending actuator (BA was developed using patented pneumatic skewed rotary elastic chambers (sREC. To analyze the actuator self-alignment properties, knowledge about the motion of this bending actuator type, the so-called skewed rotary elastic chambers bending actuator (sRECBA, is of high interest and this paper presents experimental and simulation-based kinematic investigations. First, to describe actuator motion, the finite helical axes (FHA of basic actuator elements are determined using a three-dimensional (3D camera system. Afterwards, a simplified two-dimensional (2D kinematic simulation model based on a four-bar linkage was developed and the motion was compared to the experimental data by calculating the instantaneous center of rotation (ICR. The equivalent kinematic model of the sRECBA was realized using a series of four-bar linkages and the resulting ICR was analyzed in simulation. Finally, the FHA of the sRECBA were determined and analyzed for three different specific motions. The results show that the actuator’s FHA adapt to different motions performed and it can be assumed that implicit self-alignment to the polycentric motion of the human joint axis will be provided.

  16. Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films

    International Nuclear Information System (INIS)

    Hees, J; Heidrich, N; Pletschen, W; Sah, R E; Wolfer, M; Lebedev, V; Nebel, C E; Ambacher, O; Williams, O A

    2013-01-01

    Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (10 8 cm −2 ), in the case of hydrogen-treated ND seeding particles, to very high values of 10 11 cm −2 for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young’s moduli of more than 1000 GPa. (paper)

  17. A Statistical Methodology for Determination of Safety Systems Actuation Setpoints Based on Extreme Value Statistics

    Directory of Open Access Journals (Sweden)

    D. R. Novog

    2008-01-01

    Full Text Available This paper provides a novel and robust methodology for determination of nuclear reactor trip setpoints which accounts for uncertainties in input parameters and models, as well as accounting for the variations in operating states that periodically occur. Further it demonstrates that in performing best estimate and uncertainty calculations, it is critical to consider the impact of all fuel channels and instrumentation in the integration of these uncertainties in setpoint determination. This methodology is based on the concept of a true trip setpoint, which is the reactor setpoint that would be required in an ideal situation where all key inputs and plant responses were known, such that during the accident sequence a reactor shutdown will occur which just prevents the acceptance criteria from being exceeded. Since this true value cannot be established, the uncertainties in plant simulations and plant measurements as well as operational variations which lead to time changes in the true value of initial conditions must be considered. This paper presents the general concept used to determine the actuation setpoints considering the uncertainties and changes in initial conditions, and allowing for safety systems instrumentation redundancy. The results demonstrate unique statistical behavior with respect to both fuel and instrumentation uncertainties which has not previously been investigated.

  18. Stiffness Customization and Patterning for Property Modulation of Silicone-Based Soft Pneumatic Actuators.

    Science.gov (United States)

    Sun, Yi; Yap, Hong Kai; Liang, Xinquan; Guo, Jin; Qi, Peng; Ang, Marcelo H; Yeow, Chen-Hua

    2017-09-01

    Soft pneumatic actuators (SPAs), as novel types of motion drivers for robotic devices, excel in many applications, such as rehabilitation and biomimicry, which demand compliance and softness. To further expand their scope of utilization, the SPAs should be customizable to meet the distinctive requirements of different applications. This article proposes a novel perspective on the SPA working mechanism based on stiffness distribution and then presents a versatile method called stiffness customization and patterning (SCP) for SPA body stiffness layout as a novel attempt to customize SPAs with distinctive properties. We fabricated a hybrid type of material combining unstretchable material and silicone with customizable aggregated elasticity. The tensile results showed that embedding unstretchable material directly increases the stiffness of the hybrid material sample, and our stress-strain model for SCP is able to adequately predict the elasticity of hybrid samples with specific material ratios. By applying this approach to bending-type SPAs, we are able to mitigate SPA buckling, a main failure mode of SPAs, and improve the SPA tip force by using hybrid material with globally increased stiffness. We also diversify bending modalities with different stiffness configurations in the hybrid material. SCP offers numerous ways to engineer SPAs for more applications.

  19. Performance of Optimized Prosthetic Ankle Designs That Are Based on a Hydraulic Variable Displacement Actuator (VDA).

    Science.gov (United States)

    Gardiner, James; Bari, Abu Zeeshan; Kenney, Laurence; Twiste, Martin; Moser, David; Zahedi, Saeed; Howard, David

    2017-12-01

    Current energy storage and return prosthetic feet only marginally reduce the cost of amputee locomotion compared with basic solid ankle cushioned heel feet, possibly due to their lack of push-off at the end of stance. To the best of our knowledge, a prosthetic ankle that utilizes a hydraulic variable displacement actuator (VDA) to improve push-off performance has not previously been proposed. Therefore, here we report a design optimization and simulation feasibility study for a VDA-based prosthetic ankle. The proposed device stores the eccentric ankle work done from heel strike to maximum dorsiflexion in a hydraulic accumulator and then returns the stored energy to power push-off. Optimization was used to establish the best spring characteristic and gear ratio between ankle and VDA. The corresponding simulations show that, in level walking, normal push-off is achieved and, per gait cycle, the energy stored in the accumulator increases by 22% of the requirements for normal push-off. Although the results are promising, there are many unanswered questions and, for this approach to be a success, a new miniature, low-losses, and lightweight VDA would be required that is half the size of the smallest commercially available device.

  20. Multilevel Simulation of Heterogeneous Reconfigurable Platforms

    Directory of Open Access Journals (Sweden)

    Damien Picard

    2009-01-01

    Full Text Available This paper presents a general system-level simulation and testing methodology for reconfigurable System-on-Chips, starting from behavioral specifications of system activities to multilevel simulations of accelerated tasks running on the reconfigurable circuit. The system is based on a common objectoriented environment that offers valuable debugging and probing facilities as well as integrated testing features. Our system brings these benefits to the hardware simulation, while enforcing validation through characterization tests and interoperability through on-demand mainstream tools connections. This framework has been partially developed in the scope of the EU Morpheus project and is used to validate our contribution to the spatial design task.

  1. Reconfigurable Robust Routing for Mobile Outreach Network

    Science.gov (United States)

    Lin, Ching-Fang

    2010-01-01

    The Reconfigurable Robust Routing for Mobile Outreach Network (R3MOO N) provides advanced communications networking technologies suitable for the lunar surface environment and applications. The R3MOON techn ology is based on a detailed concept of operations tailored for luna r surface networks, and includes intelligent routing algorithms and wireless mesh network implementation on AGNC's Coremicro Robots. The product's features include an integrated communication solution inco rporating energy efficiency and disruption-tolerance in a mobile ad h oc network, and a real-time control module to provide researchers an d engineers a convenient tool for reconfiguration, investigation, an d management.

  2. A novel in situ device based on a bionic piezoelectric actuator to study tensile and fatigue properties of bulk materials.

    Science.gov (United States)

    Wang, Shupeng; Zhang, Zhihui; Ren, Luquan; Zhao, Hongwei; Liang, Yunhong; Zhu, Bing

    2014-06-01

    In this work, a miniaturized device based on a bionic piezoelectric actuator was developed to investigate the static tensile and dynamic fatigue properties of bulk materials. The device mainly consists of a bionic stepping piezoelectric actuator based on wedge block clamping, a pair of grippers, and a set of precise signal test system. Tensile and fatigue examinations share a set of driving system and a set of signal test system. In situ tensile and fatigue examinations under scanning electron microscope or metallographic microscope could be carried out due to the miniaturized dimensions of the device. The structure and working principle of the device were discussed and the effects of output difference between two piezoelectric stacks on the device were theoretically analyzed. The tensile and fatigue examinations on ordinary copper were carried out using this device and its feasibility was verified through the comparison tests with a commercial tensile examination instrument.

  3. A Field Programmable Gate Array-Based Reconfigurable Smart-Sensor Network for Wireless Monitoring of New Generation Computer Numerically Controlled Machines

    Directory of Open Access Journals (Sweden)

    Ion Stiharu

    2010-08-01

    Full Text Available Computer numerically controlled (CNC machines have evolved to adapt to increasing technological and industrial requirements. To cover these needs, new generation machines have to perform monitoring strategies by incorporating multiple sensors. Since in most of applications the online Processing of the variables is essential, the use of smart sensors is necessary. The contribution of this work is the development of a wireless network platform of reconfigurable smart sensors for CNC machine applications complying with the measurement requirements of new generation CNC machines. Four different smart sensors are put under test in the network and their corresponding signal processing techniques are implemented in a Field Programmable Gate Array (FPGA-based sensor node.

  4. A Field Programmable Gate Array-Based Reconfigurable Smart-Sensor Network for Wireless Monitoring of New Generation Computer Numerically Controlled Machines

    Science.gov (United States)

    Moreno-Tapia, Sandra Veronica; Vera-Salas, Luis Alberto; Osornio-Rios, Roque Alfredo; Dominguez-Gonzalez, Aurelio; Stiharu, Ion; de Jesus Romero-Troncoso, Rene

    2010-01-01

    Computer numerically controlled (CNC) machines have evolved to adapt to increasing technological and industrial requirements. To cover these needs, new generation machines have to perform monitoring strategies by incorporating multiple sensors. Since in most of applications the online Processing of the variables is essential, the use of smart sensors is necessary. The contribution of this work is the development of a wireless network platform of reconfigurable smart sensors for CNC machine applications complying with the measurement requirements of new generation CNC machines. Four different smart sensors are put under test in the network and their corresponding signal processing techniques are implemented in a Field Programmable Gate Array (FPGA)-based sensor node. PMID:22163602

  5. A reconfigurable hybrid supervisory system for process control

    International Nuclear Information System (INIS)

    Garcia, H.E.; Ray, A.; Edwards, R.M.

    1994-01-01

    This paper presents a reconfigurable approach to decision and control systems for complex dynamic processes. The proposed supervisory control system is a reconfigurable hybrid architecture structured into three functional levels of hierarchy, namely, execution, supervision, and coordination. While the bottom execution level is constituted by either reconfigurable continuously varying or discrete event systems, the top two levels are necessarily governed by reconfigurable sets of discrete event decision and control systems. Based on the process status, the set of active control and supervisory algorithm is chosen. The reconfigurable hybrid system is briefly described along with a discussion on its implementation at the Experimental Breeder Reactor II of Argonne National Laboratory. A process control application of this hybrid system is presented and evaluated in an in-plant experiment

  6. A reconfigurable hybrid supervisory system for process control

    International Nuclear Information System (INIS)

    Garcia, H.E.; Ray, A.; Edwards, R.M.

    1994-01-01

    This paper presents a reconfigurable approach to decision and control systems for complex dynamic processes. The proposed supervisory control system is a reconfigurable hybrid architecture structured into three functional levels of hierarchy, namely, execution, supervision, and coordination. While, the bottom execution level is constituted by either reconfigurable continuously varying or discrete event systems, the top two levels are necessarily governed by reconfigurable sets of discrete event decision and control systems. Based on the process status, the set of active control and supervisory algorithm is chosen. The reconfigurable hybrid system is briefly described along with a discussion on its implementation at the Experimental Breeder Reactor 2 of Argonne National Laboratory. A process control application of this hybrid system is presented and evaluated in an in-plant experiment

  7. Transformational electronics are now reconfiguring

    KAUST Repository

    Rojas, Jhonathan Prieto

    2015-05-22

    Current developments on enhancing our smart living experience are leveraging the increased interest for novel systems that can be compatible with foldable, wrinkled, wavy and complex geometries and surfaces, and thus become truly ubiquitous and easy to deploy. Therefore, relying on innovative structural designs we have been able to reconfigure the physical form of various materials, to achieve remarkable mechanical flexibility and stretchability, which provides us with the perfect platform to develop enhanced electronic systems for application in entertainment, healthcare, fitness and wellness, military and manufacturing industry. Based on these novel structural designs we have developed a siliconbased network of hexagonal islands connected through double-spiral springs, forming an ultra-stretchable (~1000%) array for full compliance to highly asymmetric shapes and surfaces, as well as a serpentine design used to show an ultrastretchable (~800%) and flexible, spatially reconfigurable, mobile, metallic thin film copper (Cu)-based, body-integrated and non-invasive thermal heater with wireless controlling capability, reusability, heating-adaptability and affordability due to low-cost complementary metal oxide semiconductor (CMOS)-compatible integration. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  8. Cylindrical Piezoelectric Fiber Composite Actuators

    Science.gov (United States)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices include ultrasonic transducers, micro-positioning devices, buzzers, strain sensors, and clocks. The invention of such lightweight, relatively inexpensive piezoceramic-fiber-composite actuators as macro fiber composite (MFC) actuators has made it possible to obtain strains and displacements greater than those that could be generated by prior actuators based on monolithic piezoceramic sheet materials. MFC actuators are flat, flexible actuators designed for bonding to structures to apply or detect strains. Bonding multiple layers of MFC actuators together could increase force capability, but not strain or displacement capability. Cylindrical piezoelectric fiber composite (CPFC) actuators have been invented as alternatives to MFC actuators for applications in which greater forces and/or strains or displacements may be required. In essence, a CPFC actuator is an MFC or other piezoceramic fiber composite actuator fabricated in a cylindrical instead of its conventional flat shape. Cylindrical is used here in the general sense, encompassing shapes that can have circular, elliptical, rectangular or other cross-sectional shapes in the planes perpendicular to their longitudinal axes.

  9. Adaptive fuzzy observer-based stabilization of a class of uncertain time-delayed chaotic systems with actuator nonlinearities

    International Nuclear Information System (INIS)

    Shahnazi, Reza; Haghani, Adel; Jeinsch, Torsten

    2015-01-01

    An observer-based output feedback adaptive fuzzy controller is proposed to stabilize a class of uncertain chaotic systems with unknown time-varying time delays, unknown actuator nonlinearities and unknown external disturbances. The actuator nonlinearity can be backlash-like hysteresis or dead-zone. Based on universal approximation property of fuzzy systems the unknown nonlinear functions are approximated by fuzzy systems, where the consequent parts of fuzzy rules are tuned with adaptive schemes. The proposed method does not need the availability of the states and an observer based output feedback approach is proposed to estimate the states. To have more robustness and at the same time to alleviate chattering an adaptive discontinuous structure is suggested. Semi-global asymptotic stability of the overall system is ensured by proposing a suitable Lyapunov–Krasovskii functional candidate. The approach is applied to stabilize the time-delayed Lorenz chaotic system with uncertain dynamics amid significant disturbances. Analysis of simulations reveals the effectiveness of the proposed method in terms of coping well with the modeling uncertainties, nonlinearities in actuators, unknown time-varying time-delays and unknown external disturbances while maintaining asymptotic convergence

  10. Compact electrostatic comb actuator

    Science.gov (United States)

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  11. The Actuator Surface Model: A New Navier-Stokes Based Model for Rotor Computations

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zhang, J.H.; Sørensen, Jens Nørkær

    2009-01-01

    This paper presents a new numerical technique for simulating two-dimensional wind turbine flow. The method, denoted as the 2D actuator surface technique, consists of a two-dimensional Navier-Stokes solver in which the pressure distribution is represented by body forces that are distributed along ....... In the last part, the actuator surface technique is applied to compute the flow past a two-bladed vertical axis wind turbine equipped with NACA 0012 airfoils. Comparisons with experimental data show an encouraging performance of the method.......This paper presents a new numerical technique for simulating two-dimensional wind turbine flow. The method, denoted as the 2D actuator surface technique, consists of a two-dimensional Navier-Stokes solver in which the pressure distribution is represented by body forces that are distributed along...

  12. Pneumatic Rotary Actuator Position Servo System Based on ADE-PD Control

    Directory of Open Access Journals (Sweden)

    Yeming Zhang

    2018-03-01

    Full Text Available In order to accurately control the rotation position of a pneumatic rotary actuator, the flow state of the gas and the motion state of the pneumatic rotary actuator in the pneumatic rotary actuator position servo system are analyzed in this paper. The mathematical model of the system and the experiment platform are established after that. An Adaptive Differential Evolution (ADE algorithm which adaptively ameliorates the scaling factor and crossover probability in the process of individual evolution is proposed and applied to the parameter optimization of PD controller. The experimental platform is used to compare the controller with Differential Evolution (DE algorithm and NCD-PID controller. Finally, the characteristics of the system are tested by increasing the inertial load. The experimental results illustrate that system using ADE-PD control strategy has greater position precision and faster response than using DE-PD and NCD-PID strategies, and shows great robustness.

  13. Intelligent control of an IPMC actuated manipulator using emotional learning-based controller

    Science.gov (United States)

    Shariati, Azadeh; Meghdari, Ali; Shariati, Parham

    2008-08-01

    In this research an intelligent emotional learning controller, Takagi- Sugeno- Kang (TSK) is applied to govern the dynamics of a novel Ionic-Polymer Metal Composite (IPMC) actuated manipulator. Ionic-Polymer Metal Composites are active actuators that show very large deformation in existence of low applied voltage. In this research, a new IPMC actuator is considered and applied to a 2-dof miniature manipulator. This manipulator is designed for miniature tasks. The control system consists of a set of neurofuzzy controller whose parameters are adapted according to the emotional learning rules, and a critic with task to assess the present situation resulted from the applied control action in terms of satisfactory achievement of the control goals and provides the emotional signal (the stress). The controller modifies its characteristics so that the critic's stress decreased.

  14. Reconfiguring Maternity Care?

    DEFF Research Database (Denmark)

    Johannsen, Nis

    This dissertation constitutes a reflection on two initiatives seeking to reconfigure maternity care. One initiative sought to digitalise maternity records and included a pilot run of an electronic maternity record in a Danish county. The other consisted of a collaboration between a maternity ward...... at a hospital and a group of researchers which included me. Both initiatives involved numerous seemingly different interests that were held together and related to reconfiguring maternity care. None of the initiatives can unequivocally be labelled a success, as neither managed to change maternity care, at least...... experimental designs are constructed. The consequences and the politics of the proposed changes are engaged with in laboratory manner through collaborative development of the designs and through exposing them to members of field of maternity care...

  15. Validation and modification of the Blade Element Momentum theory based on comparisons with actuator disc simulations

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Bak, Christian; Døssing, Mads

    2010-01-01

    A comprehensive investigation of the Blade Element Momentum (BEM) model using detailed numerical simulations with an axis symmetric actuator disc (AD) model has been carried out. The present implementation of the BEM model is in a version where exactly the same input in the form of non-dimensiona......A comprehensive investigation of the Blade Element Momentum (BEM) model using detailed numerical simulations with an axis symmetric actuator disc (AD) model has been carried out. The present implementation of the BEM model is in a version where exactly the same input in the form of non...

  16. A self-adaption compensation control for hysteresis nonlinearity in piezo-actuated stages based on Pi-sigma fuzzy neural network

    Science.gov (United States)

    Xu, Rui; Zhou, Miaolei

    2018-04-01

    Piezo-actuated stages are widely applied in the high-precision positioning field nowadays. However, the inherent hysteresis nonlinearity in piezo-actuated stages greatly deteriorates the positioning accuracy of piezo-actuated stages. This paper first utilizes a nonlinear autoregressive moving average with exogenous inputs (NARMAX) model based on the Pi-sigma fuzzy neural network (PSFNN) to construct an online rate-dependent hysteresis model for describing the hysteresis nonlinearity in piezo-actuated stages. In order to improve the convergence rate of PSFNN and modeling precision, we adopt the gradient descent algorithm featuring three different learning factors to update the model parameters. The convergence of the NARMAX model based on the PSFNN is analyzed effectively. To ensure that the parameters can converge to the true values, the persistent excitation condition is considered. Then, a self-adaption compensation controller is designed for eliminating the hysteresis nonlinearity in piezo-actuated stages. A merit of the proposed controller is that it can directly eliminate the complex hysteresis nonlinearity in piezo-actuated stages without any inverse dynamic models. To demonstrate the effectiveness of the proposed model and control methods, a set of comparative experiments are performed on piezo-actuated stages. Experimental results show that the proposed modeling and control methods have excellent performance.

  17. Electrically Reconfigurable Liquid Crystalline Mirrors (Postprint)

    Science.gov (United States)

    2018-04-24

    focus on dynamic reconfiguration of the reflection band gap of polymer-stabilized cholesteric liquid crystals (PSCLCs). Recent research has reported the...public release: distribution unlimited. © 2018 AMERICAN CHEMICAL SOCIETY (STINFO COPY) AIR FORCE RESEARCH LABORATORY MATERIALS AND MANUFACTURING...MONITORING AGENCY ACRONYM(S) Air Force Research Laboratory Materials and Manufacturing Directorate Wright-Patterson Air Force Base, OH

  18. An orientation measurement method based on Hall-effect sensors for permanent magnet spherical actuators with 3D magnet array.

    Science.gov (United States)

    Yan, Liang; Zhu, Bo; Jiao, Zongxia; Chen, Chin-Yin; Chen, I-Ming

    2014-10-24

    An orientation measurement method based on Hall-effect sensors is proposed for permanent magnet (PM) spherical actuators with three-dimensional (3D) magnet array. As there is no contact between the measurement system and the rotor, this method could effectively avoid friction torque and additional inertial moment existing in conventional approaches. Curved surface fitting method based on exponential approximation is proposed to formulate the magnetic field distribution in 3D space. The comparison with conventional modeling method shows that it helps to improve the model accuracy. The Hall-effect sensors are distributed around the rotor with PM poles to detect the flux density at different points, and thus the rotor orientation can be computed from the measured results and analytical models. Experiments have been conducted on the developed research prototype of the spherical actuator to validate the accuracy of the analytical equations relating the rotor orientation and the value of magnetic flux density. The experimental results show that the proposed method can measure the rotor orientation precisely, and the measurement accuracy could be improved by the novel 3D magnet array. The study result could be used for real-time motion control of PM spherical actuators.

  19. Smart Tendon Actuated Flexible Actuator

    Directory of Open Access Journals (Sweden)

    Md. Masum Billah

    2015-01-01

    Full Text Available We investigate the kinematic feasibility of a tendon-based flexible parallel platform actuator. Much of the research on tendon-driven Stewart platforms is devoted either to the completely restrained positioning mechanism (CRPM or to one particular type of the incompletely restrained positioning mechanism (IRPM where the external force is provided by the gravitational pull on the platform such as in cable-suspended Stewart platforms. An IRPM-based platform is proposed which uses the external force provided by a compliant member. The compliant central column allows the configuration to achieve n DOFs with n tendons. In particular, this investigation focuses on the angular deflection of the upper platform with respect to the lower platform. The application here is aimed at developing a linkable module that can be connected to one another so as to form a “snake robot” of sorts. Since locomotion takes precedence over positioning in this application, a 3-DOF Stewart platform is adopted. For an arbitrary angular displace of the end-effector, the corresponding length of each tendon can be determined through inverse kinematics. Mathematical singularities are investigated using the traditional analytical method of defining the Jacobian.

  20. Note: A novel rotary actuator driven by only one piezoelectric actuator.

    Science.gov (United States)

    Huang, Hu; Fu, Lu; Zhao, Hongwei; Shi, Chengli; Ren, Luquan; Li, Jianping; Qu, Han

    2013-09-01

    This paper presents a novel piezo-driven rotary actuator based on the parasitic motion principle. Output performances of the rotary actuator were tested and discussed. Experiment results indicate that using only one piezoelectric actuator and simple sawtooth wave control, the rotary actuator reaches the rotation velocity of about 20,097 μrad/s when the driving voltage is 100 V and the driving frequency is 90 Hz. The actuator can rotate stably with the minimum resolution of 0.7 μrad. This paper verifies feasibility of the parasitic motion principle for applications of rotary actuators, providing new design ideas for precision piezoelectric rotary actuators.

  1. Magnetic fish-robot based on multi-motion control of a flexible magnetic actuator.

    Science.gov (United States)

    Kim, Sung Hoon; Shin, Kyoosik; Hashi, Shuichiro; Ishiyama, Kazushi

    2012-09-01

    This paper presents a biologically inspired fish-robot driven by a single flexible magnetic actuator with a rotating magnetic field in a three-axis Helmholtz coil. Generally, magnetic fish-robots are powered by alternating and gradient magnetic fields, which provide a single motion such as bending the fish-robot's fins. On the other hand, a flexible magnetic actuator driven by an external rotating magnetic field can create several gaits such as the bending vibration, the twisting vibration, and their combination. Most magnetic fish-like micro-robots do not have pectoral fins on the side and are simply propelled by the tail fin. The proposed robot can swim and perform a variety of maneuvers with the addition of pectoral fins and control of the magnetic torque direction. In this paper, we find that the robot's dynamic actuation correlates with the magnetic actuator and the rotating magnetic field. The proposed robot is also equipped with new features, such as a total of six degrees of freedom, a new control method that stabilizes posture, three-dimensional swimming, a new velocity control, and new turning abilities.

  2. Magnetic fish-robot based on multi-motion control of a flexible magnetic actuator

    International Nuclear Information System (INIS)

    Kim, Sung Hoon; Hashi, Shuichiro; Ishiyama, Kazushi; Shin, Kyoosik

    2012-01-01

    This paper presents a biologically inspired fish-robot driven by a single flexible magnetic actuator with a rotating magnetic field in a three-axis Helmholtz coil. Generally, magnetic fish-robots are powered by alternating and gradient magnetic fields, which provide a single motion such as bending the fish-robot's fins. On the other hand, a flexible magnetic actuator driven by an external rotating magnetic field can create several gaits such as the bending vibration, the twisting vibration, and their combination. Most magnetic fish-like micro-robots do not have pectoral fins on the side and are simply propelled by the tail fin. The proposed robot can swim and perform a variety of maneuvers with the addition of pectoral fins and control of the magnetic torque direction. In this paper, we find that the robot's dynamic actuation correlates with the magnetic actuator and the rotating magnetic field. The proposed robot is also equipped with new features, such as a total of six degrees of freedom, a new control method that stabilizes posture, three-dimensional swimming, a new velocity control, and new turning abilities. (paper)

  3. Maximization of integral outlet quantities of an axisymmetric synthetic jet actuator based on a loudspeaker

    Czech Academy of Sciences Publication Activity Database

    Kordík, Jozef; Trávníček, Zdeněk

    2016-01-01

    Roč. 114, March (2016), č. článku 02152. ISSN 2101-6275. [International Conference on Experimental Fluid Mechanics /10./. Praha, 17.11.2015-20.11.2015] R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * synthetic jet actuator * resonance Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts

  4. A Method for Aileron Actuator Fault Diagnosis Based on PCA and PGC-SVM

    Directory of Open Access Journals (Sweden)

    Wei-Li Qin

    2016-01-01

    Full Text Available Aileron actuators are pivotal components for aircraft flight control system. Thus, the fault diagnosis of aileron actuators is vital in the enhancement of the reliability and fault tolerant capability. This paper presents an aileron actuator fault diagnosis approach combining principal component analysis (PCA, grid search (GS, 10-fold cross validation (CV, and one-versus-one support vector machine (SVM. This method is referred to as PGC-SVM and utilizes the direct drive valve input, force motor current, and displacement feedback signal to realize fault detection and location. First, several common faults of aileron actuators, which include force motor coil break, sensor coil break, cylinder leakage, and amplifier gain reduction, are extracted from the fault quadrantal diagram; the corresponding fault mechanisms are analyzed. Second, the data feature extraction is performed with dimension reduction using PCA. Finally, the GS and CV algorithms are employed to train a one-versus-one SVM for fault classification, thus obtaining the optimal model parameters and assuring the generalization of the trained SVM, respectively. To verify the effectiveness of the proposed approach, four types of faults are introduced into the simulation model established by AMESim and Simulink. The results demonstrate its desirable diagnostic performance which outperforms that of the traditional SVM by comparison.

  5. Performance of synthetic jet actuators based on hybrid and double-acting principles

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Tesař, Václav; Kordík, Jozef

    2008-01-01

    Roč. 11, č. 3 (2008), s. 221-229 ISSN 1343-8875 R&D Projects: GA ČR GA101/07/1499; GA AV ČR(CZ) IAA200760801 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * impinging jet * actuator Subject RIV: BK - Fluid Dynamics Impact factor: 0.943, year: 2008

  6. Numerical simulation of the aerodynamic field in complex terrain wind farm based on actuator disk model

    DEFF Research Database (Denmark)

    Xu, Chang; Li, Chen Qi; Han, Xing Xing

    2015-01-01

    Study on the aerodynamic field in complex terrain is significant to wind farm micro-sitting and wind power prediction. This paper modeled the wind turbine through an actuator disk model, and solved the aerodynamic field by CFD to study the influence of meshing, boundary conditions and turbulence ...

  7. Numerical Study of Wind Turbine Wake Modeling Based on a Actuator Surface Model

    DEFF Research Database (Denmark)

    Zhou, Huai-yang; Xu, Chang; Han, Xing Xing

    2017-01-01

    In the Actuator Surface Model (ALM), the turbine blades are represented by porous surfaces of velocity and pressure discontinuities to model the action of lifting surfaces on the flow. The numerical simulation is implemented on FLUENT platform combined with N-S equations. This model is improved o...

  8. High-performance hybrid (electrostatic double-layer and faradaic capacitor-based) polymer actuators incorporating nickel oxide and vapor-grown carbon nanofibers.

    Science.gov (United States)

    Terasawa, Naohiro; Asaka, Kinji

    2014-12-02

    The electrochemical and electromechanical properties of polymeric actuators prepared using nickel peroxide hydrate (NiO2·xH2O) or nickel peroxide anhydride (NiO2)/vapor-grown carbon nanofibers (VGCF)/ionic liquid (IL) electrodes were compared with actuators prepared using solely VGCFs or single-walled carbon nanotubes (SWCNTs) and an IL. The electrode in these actuator systems is equivalent to an electrochemical capacitor (EC) exhibiting both electrostatic double-layer capacitor (EDLC)- and faradaic capacitor (FC)-like behaviors. The capacitance of the metal oxide (NiO2·xH2O or NiO2)/VGCF/IL electrode is primarily attributable to the EDLC mechanism such that, at low frequencies, the strains exhibited by the NiO2·xH2O/VGCF/IL and NiO2/VGCF/IL actuators primarily result from the FC mechanism. The VGCFs in the NiO2·xH2O/VGCF/IL and NiO2/VGCF/IL actuators strengthen the EDLC mechanism and increase the electroconductivity of the devices. The mechanism underlying the functioning of the NiO2·xH2O/VGCF/IL actuator in which NiO2·xH2O/VGCF = 1.0 was found to be different from that of the devices produced using solely VGCFs or SWCNTs, which exhibited only the EDLC mechanism. In addition, it was found that both NiO2 and VGCFs are essential with regard to producing actuators that are capable of exhibiting strain levels greater than those of SWCNT-based polymer actuators and are thus suitable for practical applications. Furthermore, the frequency dependence of the displacement responses of the NiO2·xH2O/VGCF and NiO2/VGCF polymer actuators were successfully simulated using a double-layer charging kinetic model. This model, which accounted for the oxidization and reduction reactions of the metal oxide, can also be applied to SWCNT-based actuators. The results of electromechanical response simulations for the NiO2·xH2O/VGCF and NiO2/VGCF actuators predicted the strains at low frequencies as well as the time constants of the devices, confirming that the model is applicable

  9. Application of condition-based HRA method for a manual actuation of the safety features in a nuclear power Plant

    International Nuclear Information System (INIS)

    Kang, Hyun Gook; Jang, Seung-Cheol

    2006-01-01

    A practical approach to develop a more realistic fault-tree model with a consideration of various conditions endured by a human operator is proposed. In safety-critical systems, the generation failure of an actuation signal is caused by the concurrent failures of the automated systems and an operator action. These two sources of safety signals are complicatedly correlated. The failures of sensors or automated systems will cause a lack of necessary information for a human operator and result in error-forcing contexts such as the loss of corresponding alarms and indications. It is well known that the error-forcing contexts largely affect the operator's performance. An automated system which consists of multiple processing channels and complex components is also affected by the availability of the sensors. This paper proposes a condition-based human reliability assessment (CBHRA) method in order to address these complicated conditions in a practical way. We apply the CBHRA method to the manual actuation of the safety features such as a reactor trip and auxiliary feedwater actuation in Korean Standard Nuclear Power Plants. Even the human error probability of each given condition is simply assumed, the application results prove that the CBHRA effectively accommodates the complicated error-forcing contexts into the fault trees

  10. OffWindSolver: Wind farm design tool based on actuator line/actuator disk concept in OpenFoam architecture

    Directory of Open Access Journals (Sweden)

    Panjwani Balram

    2014-01-01

    Full Text Available Wind energy is a good alternative to meet the energy requirements in some parts of the world; however the efficiency of wind farm depends on the optimized location of the wind turbines. Therefore a software tool that is capable of predicting the in-situ performance of multiple turbine installations in different operating conditions with reliable accuracy is needed. In present study wind farm layout design tool OffWindSolver is developed within the OpenFoam architecture. Unsteady PisoFoam solver is extended to account for wind turbines, where each turbine is modeled as a sink term in the momentum equation. Turbine modeling is based on actuator line concepts derived from SOWFA code, where each blade of the turbine is represented as a line. The loading on each line/blade of the turbine is estimated using the Blade Element Method (BEM. The inputs for the solver are tabulated airfoil aerodynamic data, dimension and height of the wind turbines, wind magnitude and direction. OffWindSolver is validated for a real wind farm – Lillgrund offshore facility in Sweden/Denmark operated by Vattenfall Vindkraft AB. Because of the scale of the computation, we only examine the effect of wind from one direction at one speed. In the absence of time dependent Marine Atmospheric Boundary Layer (MABL, a log wind profile with surface roughness of 0.04 is used at the inlet. The simulated power production of each turbine is compared to the field data and large-eddy simulation. The overall power of the wind farm is well predicted. The simulation shows the significant decreases of the power for those turbines that were in the wake.

  11. Active vibration control of a full scale aircraft wing using a reconfigurable controller

    Science.gov (United States)

    Prakash, Shashikala; Renjith Kumar, T. G.; Raja, S.; Dwarakanathan, D.; Subramani, H.; Karthikeyan, C.

    2016-01-01

    This work highlights the design of a Reconfigurable Active Vibration Control (AVC) System for aircraft structures using adaptive techniques. The AVC system with a multichannel capability is realized using Filtered-X Least Mean Square algorithm (FxLMS) on Xilinx Virtex-4 Field Programmable Gate Array (FPGA) platform in Very High Speed Integrated Circuits Hardware Description Language, (VHDL). The HDL design is made based on Finite State Machine (FSM) model with Floating point Intellectual Property (IP) cores for arithmetic operations. The use of FPGA facilitates to modify the system parameters even during runtime depending on the changes in user's requirements. The locations of the control actuators are optimized based on dynamic modal strain approach using genetic algorithm (GA). The developed system has been successfully deployed for the AVC testing of the full-scale wing of an all composite two seater transport aircraft. Several closed loop configurations like single channel and multi-channel control have been tested. The experimental results from the studies presented here are very encouraging. They demonstrate the usefulness of the system's reconfigurability for real time applications.

  12. Electrical actuation of dielectric droplets

    International Nuclear Information System (INIS)

    Kumari, N; Bahadur, V; Garimella, S V

    2008-01-01

    Electrical actuation of liquid droplets at the microscale offers promising applications in the fields of microfluidics and lab-on-a-chip devices. Much prior research has targeted the electrical actuation of electrically conducting liquid droplets; however, the actuation of dielectric droplets has remained relatively unexplored, despite the advantages associated with the use of a dielectric droplet. This paper presents modeling and experimental results on the electrical actuation of dielectric droplets between two flat plates. A first-order analytical model, based on the energy-minimization principle, is developed to estimate the electrical actuation force on a dielectric droplet as it moves between two flat plates. Two versions of this analytical model are benchmarked for their suitability and accuracy against a detailed numerical model. The actuation force prediction is then combined with available semi-analytical expressions for predicting the forces opposing droplet motion to develop a model that predicts transient droplet motion under electrical actuation. Electrical actuation of dielectric droplets is experimentally demonstrated by moving transformer oil droplets between two flat plates under the influence of an actuation voltage. Droplet velocities and their dependence on the plate spacing and the applied voltage are experimentally measured and showed reasonable agreement with predictions from the models developed

  13. Repetition or Reconfiguration

    DEFF Research Database (Denmark)

    Andersen, Kristina Vaarst

    , the cognitive quality of knowledge held by individual professionals is the key microfoundation for project level performance. This paper empirically tests effects of project participants with and without knowledge diversity for project level performance for projects aiming for varying degrees of repetition...... and reconfiguration. The results indicate that project performance benefits form contributions from individuals holding diverse knowledge only when projects aim for high differentiation levels. This positive association is not just moderated, it may even be reversed in the case of professionals participating in low...

  14. Design of a novel parallel reconfigurable machine tool

    CSIR Research Space (South Africa)

    Modungwa, D

    2008-06-01

    Full Text Available of meeting the demands for high mechanical dexterity adaptation as well as high stiffness necessary for mould and die re-conditioning. This paper presents, the design of parallel reconfigurable machine tool (PRMT) based on both application...

  15. Nonlinear Analysis of Actuation Performance of Shape Memory Alloy Composite Film Based on Silicon Substrate

    Directory of Open Access Journals (Sweden)

    Shuangshuang Sun

    2014-01-01

    Full Text Available The mechanical model of the shape memory alloy (SMA composite film with silicon (Si substrate was established by the method of mechanics of composite materials. The coupled action between the SMA film and Si substrate under thermal loads was analyzed by combining static equilibrium equations, geometric equations, and physical equations. The material nonlinearity of SMA and the geometric nonlinearity of bending deformation were both considered. By simulating and analyzing the actuation performance of the SMA composite film during one cooling-heating thermal cycle, it is found that the final cooling temperature, boundary condition, and the thickness of SMA film have significant effects on the actuation performance of the SMA composite film. Besides, the maximum deflection of the SMA composite film is affected obviously by the geometric nonlinearity of bending deformation when the thickness of SMA film is very large.

  16. Capacitive sensing of droplets for microfluidic devices based on thermocapillary actuation

    OpenAIRE

    Chen, Jian Z.; Darhuber, Anton A.; Troian, Sandra M.; Wagner, Sigurd

    2004-01-01

    The design and performance of a miniaturized coplanar capacitive sensor is presented whose electrode arrays can also function as resistive microheaters for thermocapillary actuation of liquid films and droplets. Optimal compromise between large capacitive signal and high spatial resolution is obtained for electrode widths comparable to the liquid film thickness measured, in agreement with supporting numerical simulations which include mutual capacitance effects. An interdigitated, variable wi...

  17. Thermo-mechanical actuator-based miniature tagging module for localization in capsule endoscopy

    Science.gov (United States)

    Chandrappan, Jayakrishnan; Ruiqi, Lim; Su, Nandar; Yen Yi, Germaine Hoe; Vaidyanathan, Kripesh

    2011-04-01

    Capsule endoscopy is a frontline medical diagnostic tool for the gastro intestinal tract disorders. During diagnosis, efficient localization techniques are essential to specify a pathological area that may require further diagnosis or treatment. This paper presents the development of a miniature tagging module that relies on a novel concept to label the region of interest and has the potential to integrate with a capsule endoscope. The tagging module is a compact thermo-mechanical actuator loaded with a biocompatible micro tag. A low power microheater attached to the module serves as the thermal igniter for the mechanical actuator. At optimum temperature, the actuator releases the micro tag instantly and penetrates the mucosa layer of a GI tract, region of interest. Ex vivo animal trials are conducted to verify the feasibility of the tagging module concept. X-ray imaging is used to detect the location of the micro tag embedded in the GI tract wall. The method is successful, and radiopaque micro tags can provide valuable pre-operative position information on the infected area to facilitate further clinical procedures.

  18. A novel hybrid actuation mechanism based XY nanopositioning stage with totally decoupled kinematics

    Science.gov (United States)

    Zhu, Wu-Le; Zhu, Zhiwei; Guo, Ping; Ju, Bing-Feng

    2018-01-01

    This paper reports the design, analysis and testing of a parallel two degree-of-freedom piezo-actuated compliant stage for XY nanopositioning by introducing an innovative hybrid actuation mechanism. It mainly features the combination of two Scott-Russell and a half-bridge mechanisms for double-stage displacement amplification as well as moving direction modulation. By adopting the leaf-type double parallelogram (LTDP) structures at both input and output ends of the hybrid mechanism, the lateral stiffness and dynamic characteristics are significantly improved while the parasitic motions are greatly eliminated. The XY nanopositioning stage is constructed with two orthogonally configured hybrid mechanisms along with the LTDP mechanisms for totally decoupled kinematics at both input and output ends. An analytical model was established to describe the complete elastic deformation behavior of the stage, with further verification through the finite element simulation. Finally, experiments were implemented to comprehensively evaluate both the static and dynamic performances of the proposed stage. Closed-loop control of the piezoelectric actuators (PEA) by integrating strain gauges was also conducted to effectively eliminate the nonlinear hysteresis of the stage.

  19. Structural Technology Evaluation and Analysis Program (STEAP). Delivery Order 0037: Prognosis-Based Control Reconfiguration for an Aircraft with Faulty Actuator to Enable Performance in a Degraded State

    Science.gov (United States)

    2010-12-01

    excessive rates of degradation during the mis- sion. 3. To validate the model and control strategies, a hardware in loop methodology will be developed...the simulation is called an onboard-controller-in-the-loop simulation (OILS) or OBC-in-the-loop simulation. 4.1.1 Advantages of HILS Hardware - in - loop -simulation

  20. Organizational Reconfiguration and Strategic Response

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Pedersen, Torben

    2014-01-01

    this, firms need a high degree of architectural knowledge, which is typically gained through learning by doing. We therefore argue that firms with more offshoring experience are more likely to include organizational objectives in their offshoring strategies. We develop and find support......The purpose of this paper is to investigate the effect of the organizational reconfiguration of offshoring on firms’ strategies. A consequence of offshoring is the need to reintegrate the geographically relocated organizational activities into a coherent organizational architecture. In order to do...... for this hypothesis using a mixed-method approach based on a qualitative case study and comprehensive data from the Offshoring Research Network. These findings contribute to research on the organizational design and architecture of offshoring and the dynamics of organizational architectures....

  1. Highly Reconfigurable Beamformer Stimulus Generator

    Directory of Open Access Journals (Sweden)

    Vaviļina E.

    2018-02-01

    Full Text Available The present paper proposes a highly reconfigurable beamformer stimulus generator of radar antenna array, which includes three main blocks: settings of antenna array, settings of objects (signal sources and a beamforming simulator. Following from the configuration of antenna array and object settings, different stimulus can be generated as the input signal for a beamformer. This stimulus generator is developed under a greater concept with two utterly independent paths where one is the stimulus generator and the other is the hardware beamformer. Both paths can be complemented in final and in intermediate steps as well to check and improve system performance. This way the technology development process is promoted by making each of the future hardware steps more substantive. Stimulus generator configuration capabilities and test results are presented proving the application of the stimulus generator for FPGA based beamforming unit development and tuning as an alternative to an actual antenna system.

  2. Highly Reconfigurable Beamformer Stimulus Generator

    Science.gov (United States)

    Vaviļina, E.; Gaigals, G.

    2018-02-01

    The present paper proposes a highly reconfigurable beamformer stimulus generator of radar antenna array, which includes three main blocks: settings of antenna array, settings of objects (signal sources) and a beamforming simulator. Following from the configuration of antenna array and object settings, different stimulus can be generated as the input signal for a beamformer. This stimulus generator is developed under a greater concept with two utterly independent paths where one is the stimulus generator and the other is the hardware beamformer. Both paths can be complemented in final and in intermediate steps as well to check and improve system performance. This way the technology development process is promoted by making each of the future hardware steps more substantive. Stimulus generator configuration capabilities and test results are presented proving the application of the stimulus generator for FPGA based beamforming unit development and tuning as an alternative to an actual antenna system.

  3. Reconfigurable multiport EPON repeater

    Science.gov (United States)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  4. Tracking Control of Shape-Memory-Alloy Actuators Based on Self-Sensing Feedback and Inverse Hysteresis Compensation

    Directory of Open Access Journals (Sweden)

    Shu-Hung Liu

    2009-12-01

    Full Text Available Shape memory alloys (SMAs offer a high power-to-weight ratio, large recovery strain, and low driving voltages, and have thus attracted considerable research attention. The difficulty of controlling SMA actuators arises from their highly nonlinear hysteresis and temperature dependence. This paper describes a combination of self-sensing and model-based control, where the model includes both the major and minor hysteresis loops as well as the thermodynamics effects. The self-sensing algorithm uses only the power width modulation (PWM signal and requires no heavy equipment. The method can achieve high-accuracy servo control and is especially suitable for miniaturized applications.

  5. A Multi-Agent-Based Intelligent Sensor and Actuator Network Design for Smart House and Home Automation

    Directory of Open Access Journals (Sweden)

    Fei Hu

    2013-08-01

    Full Text Available The smart-house technology aims to increase home automation and security with reduced energy consumption. A smart house consists of various intelligent sensors and actuators operating on different platforms with conflicting objectives. This paper proposes a multi-agent system (MAS design framework to achieve smart house automation. The novelties of this work include the developments of (1 belief, desire and intention (BDI agent behavior models; (2 a regulation policy-based multi-agent collaboration mechanism; and (3 a set of metrics for MAS performance evaluation. Simulations of case studies are performed using the Java Agent Development Environment (JADE to demonstrate the advantages of the proposed method.

  6. A FEM-Experimental Approach for the Development of a Conceptual Linear Actuator Based on Tendril’s Free Coiling

    Directory of Open Access Journals (Sweden)

    Luca Cortese

    2017-01-01

    Full Text Available Within the vastness of the plant species, certain living systems show tendril structures whose motion is of particular interest for biomimetic engineers. Tendrils sense and coil around suitable grips, and by shortening in length, they erect the remaining plant body. To achieve contraction, tendrils rotate along their main axis and shift from a linear to a double-spring geometry. This phenomenon is denoted as the free-coiling phase. In this work, with the aim of understanding the fundamentals of the mechanics behind the free coiling, a reverse-engineering approach based on the finite element method was firstly applied. The model consisted of an elongated cylinder with suitable material properties, boundary, and loading conditions, in order to reproduce the kinematics of the tendril. The simulation succeeded in mimicking coiling faithfully and was therefore used to validate a tentative linear actuator model based on the plant’s working principle. More in detail, exploiting shape memory alloy materials to obtain large reversible deformations, the main tendril features were implemented into a nickel-titanium spring-based testing model. The results of the experimental tests confirmed the feasibility of the idea in terms of both functioning principles and actual performance. It can be concluded that the final set-up can be used as a base for a prototype design of a new kind of a linear actuator.

  7. Piezoelectric self-sensing actuator for active vibration control of motorized spindle based on adaptive signal separation

    Science.gov (United States)

    He, Ye; Chen, Xiaoan; Liu, Zhi; Qin, Yi

    2018-06-01

    The motorized spindle is the core component of CNC machine tools, and the vibration of it reduces the machining precision and service life of the machine tools. Owing to the fast response, large output force, and displacement of the piezoelectric stack, it is often used as the actuator in the active vibration control of the spindle. A piezoelectric self-sensing actuator (SSA) can reduce the cost of the active vibration control system and simplify the structure by eliminating the use of a sensor, because a SSA can have both actuating and sensing functions at the same time. The signal separation method of a SSA based on a bridge circuit is widely applied because of its simple principle and easy implementation. However, it is difficult to maintain dynamic balance of the circuit. Prior research has used adaptive algorithm to balance of the bridge circuit on the flexible beam dynamically, but those algorithms need no correlation between sensing and control voltage, which limit the applications of SSA in the vibration control of the rotor-bearing system. Here, the electromechanical coupling model of the piezoelectric stack is established, followed by establishment of the dynamic model of the spindle system. Next, a new adaptive signal separation method based on the bridge circuit is proposed, which can separate relative small sensing voltage from related mixed voltage adaptively. The experimental results show that when the self-sensing signal obtained from the proposed method is used as a displacement signal, the vibration of the motorized spindle can be suppressed effectively through a linear quadratic Gaussian (LQG) algorithm.

  8. Modeling of an ionic polymer metal composite actuator based on an extended Kalman filter trained neural network

    International Nuclear Information System (INIS)

    Truong, Dinh Quang; Ahn, Kyoung Kwan

    2014-01-01

    An ion polymer metal composite (IPMC) is an electroactive polymer that bends in response to a small applied electric field as a result of mobility of cations in the polymer network and vice versa. This paper presents an innovative and accurate nonlinear black-box model (NBBM) for estimating the bending behavior of IPMC actuators. The model is constructed via a general multilayer perceptron neural network (GMLPNN) integrated with a smart learning mechanism (SLM) that is based on an extended Kalman filter with self-decoupling ability (SDEKF). Here the GMLPNN is built with an ability to autoadjust its structure based on its characteristic vector. Furthermore, by using the SLM based on the SDEKF, the GMLPNN parameters are optimized with small computational effort, and the modeling accuracy is improved. An apparatus employing an IPMC actuator is first set up to investigate the IPMC characteristics and to generate the data for training and validating the model. The advanced NBBM model for the IPMC system is then created with the proper inputs to estimate IPMC tip displacement. Next, the model is optimized using the SLM mechanism with the training data. Finally, the optimized NBBM model is verified with the validating data. A comparison between this model and the previously developed model is also carried out to prove the effectiveness of the proposed modeling technique. (paper)

  9. Wavefront correction system based on an equilateral triangular arrangement of actuators

    International Nuclear Information System (INIS)

    Salmon, J.T.; Bergum, J.W.; Kartz, M.W.; Presta, R.W.; Swift, C.D.

    1993-02-01

    Atomic Vapor Laser Isotope Separation (AVLIS) requires the copropagation of multiple beams at different wavelengths and at average powers exceeding 1 kW. Although mirror coatings are used that absorb less than one part in 10 5 , the beams still suffer from thermally induced phase distortions, both in the dye amplifiers and in transmissive optics, such as beam combiners and vacuum windows. These aberrations are 2nd-order and 3rd-order and can reach 5 waves peak-to-valley (p-v), which causes the beam to distort and break up when propagated over large distances. The magnitude of the aberrations scales with power, with time constants on the order of 30 seconds. Previous adaptive systems that have been developed corrected these thermally induced phase distortions of both 2nd-order and 3rd-order; however, these systems had limited spatial resolution and in some cases marginal stability. The authors have developed a new adaptive optics system where both the actuators of the deformable mirror and the lenslets of the Hartmann sensor are arranged with centers at the vertices of equilateral triangles. The wavefront sensor is a video Hartmann sensor that also uses an equilateral array of lenslets. The controller hardware uses a VME bus. The design minimizes the generation of reflected wavefronts higher than first order across each lenslet for large excursions of actuators from positions where the mirror is flat and, thus maximizes the precision of the slopes measured by the Hartmann sensor. The design is also immune to the waffle mode that is present in the reconstructors of adaptive optics systems where actuators are arranged in a square array

  10. Performance of optimised prosthetic ankle designs that are based on a hydraulic variable displacement actuator (VDA)

    OpenAIRE

    Gardiner, JD; Bari, AZ; Kenney, LPJ; Twiste, M; Moser, D; Zahedi, S; Howard, D

    2017-01-01

    Current energy storage and return (ESR) prosthetic\\ud feet only marginally reduce the cost of amputee locomotion\\ud compared to basic solid ankle cushioned heel (SACH) feet,\\ud possibly due to their lack of push-off at the end of stance. To our knowledge, a prosthetic ankle that utilises a hydraulic variable displacement actuator (VDA) to improve push-off performance has not previously been proposed. Therefore, here we report a design optimisation and simulation feasibility study for a VDA ba...

  11. Pulse mode actuation-readout system based on MEMS resonator for liquid sensing

    DEFF Research Database (Denmark)

    Tang, Meng; Cagliani, Alberto; Davis, Zachary James

    2014-01-01

    A MEMS (Micro-Electro-Mechanical Systems) bulk disk resonator is applied for mass sensing under its dynamic mode. The classical readout circuitry involves sophisticated feedback loop and feedthrough compensation. We propose a simple straightforward non-loop pulse mode actuation and capacitive...... readout scheme. In order to verify its feasibility in liquid bio-chemical sensing environment, an experimental measurement is conducted with humidity sensing application. The measured resonant frequency changes 60kHz of 67.7MHz with a humidity change of 0~80%....

  12. Towards a model-based development approach for wireless sensor-actuator network protocols

    DEFF Research Database (Denmark)

    Kumar S., A. Ajith; Simonsen, Kent Inge

    2014-01-01

    Model-Driven Software Engineering (MDSE) is a promising approach for the development of applications, and has been well adopted in the embedded applications domain in recent years. Wireless Sensor Actuator Networks consisting of resource constrained hardware and platformspecific operating system...... induced due to manual translations. With the use of formal semantics in the modeling approach, we can further ensure the correctness of the source model by means of verification. Also, with the use of network simulators and formal modeling tools, we obtain a verified and validated model to be used...

  13. Reconfigurable control of a power plant deaerator using learning automata

    International Nuclear Information System (INIS)

    Garcia, H.E.; Ray, A.; Edwards, R.M.

    1991-01-01

    A deaerating feedwater heater, equipped with a water level controller and a pressure controller, has been chosen to investigate the feasibility of a reconfigurable control scheme for power plants by incorporating the concept of learning automata. In this paper simulation results based on a model of the Experimental Breeder Reactor (EBR-II) at the Argonne National Laboratory site in Idaho are presented to demonstrate the efficacy of the reconfigurable control scheme

  14. Reconfigurable assembly work station

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yhu-Tin; Abell, Jeffrey A.; Spicer, John Patrick

    2017-11-14

    A reconfigurable autonomous workstation includes a multi-faced superstructure including a horizontally-arranged frame section supported on a plurality of posts. The posts form a plurality of vertical faces arranged between adjacent pairs of the posts, the faces including first and second faces and a power distribution and position reference face. A controllable robotic arm suspends from the rectangular frame section, and a work table fixedly couples to the power distribution and position reference face. A plurality of conveyor tables are fixedly coupled to the work table including a first conveyor table through the first face and a second conveyor table through the second face. A vision system monitors the work table and each of the conveyor tables. A programmable controller monitors signal inputs from the vision system to identify and determine orientation of the component on the first conveyor table and control the robotic arm to execute an assembly task.

  15. Compact, Frequency Reconfigurable, Printed Monopole Antenna

    Directory of Open Access Journals (Sweden)

    Ricardo Gonçalves

    2012-01-01

    Full Text Available This paper proposes a possible implementation of a compact printed monopole antenna, useful to operate in UMTS and WLAN bands. In order to accomplish that, a miniaturization technique based on the application of chip inductors is used in conjunction with frequency reconfiguration capability. The chip inductors change the impedance response of the monopole, allowing to reduce the resonant frequency. In order to be able to operate the antenna in these two different frequencies, an antenna reconfiguration technique based on PIN diodes is applied. This procedure allows the change of the active form of the antenna leading to a shift in the resonant frequency. The prototype measurements show good agreement with the simulation results.

  16. Lattice Automata for Control of Self-Reconfigurable Robots

    DEFF Research Database (Denmark)

    Støy, Kasper

    2015-01-01

    are extreme versatility and robustness. The organisation of self-reconfigurable robots in a lattice structure and the emphasis on local communication between modules mean that lattice automata are a useful basis for control of self-reconfigurable robots. However, there are significant differences which arise...... mainly from the physical nature of self-reconfigurable robots as opposed to the virtual nature of lattice automata. The problems resulting from these differences are mutual exclusion, handling motion constraints of modules, and unrealistic assumption about global, spatial orientation. Despite...... these problems the self-reconfigurable robot community has successfully applied lattice automata to simple control problems. However, for more complex problems hybrid solutions based on lattice automata and distributed algorithms are used. Hence, lattice automata have shown to have potential for the control...

  17. A Portable, Air-Jet-Actuator-Based Device for System Identification

    Science.gov (United States)

    Staats, Wayne; Belden, Jesse; Mazumdar, Anirban; Hunter, Ian

    2010-11-01

    System identification (ID) of human and robotic limbs could help in diagnosis of ailments and aid in optimization of control parameters and future redesigns. We present a self-contained actuator, which uses the Coanda effect to rapidly switch the direction of a high speed air jet to create a binary stochastic force input to a limb for system ID. The design of the actuator is approached with the goal of creating a portable device, which could deployed on robot or human limbs for in situ identification. The viability of the device is demonstrated by performing stochastic system ID on an underdamped elastic beam system with fixed inertia and stiffness, and variable damping. The non-parametric impulse response yielded from the stochastic system ID is modeled as a second order system, and the resultant parameters are found to be in excellent agreement with those found using more traditional system ID techniques. The current design could be further miniaturized and developed as a portable, wireless, on-site multi-axis system identification system for less intrusive and more widespread use.

  18. Designing Secure Systems on Reconfigurable Hardware

    OpenAIRE

    Huffmire, Ted; Brotherton, Brett; Callegari, Nick; Valamehr, Jonathan; White, Jeff; Kastner, Ryan; Sherwood, Ted

    2008-01-01

    The extremely high cost of custom ASIC fabrication makes FPGAs an attractive alternative for deployment of custom hardware. Embedded systems based on reconfigurable hardware integrate many functions onto a single device. Since embedded designers often have no choice but to use soft IP cores obtained from third parties, the cores operate at different trust levels, resulting in mixed trust designs. The goal of this project is to evaluate recently proposed security primitives for reconfigurab...

  19. ALI (Autonomous Lunar Investigator): Revolutionary Approach to Exploring the Moon with Addressable Reconfigurable Technology

    Science.gov (United States)

    Clark, P. E.; Curtis, S. A.; Rilee, M. L.; Floyd, S. R.

    2005-01-01

    Addressable Reconfigurable Technology (ART) based structures: Mission Concepts based on Addressable Reconfigurable Technology (ART), originally studied for future ANTS (Autonomous Nanotechnology Swarm) Space Architectures, are now being developed as rovers for nearer term use in lunar and planetary surface exploration. The architecture is based on the reconfigurable tetrahedron as a building block. Tetrahedra are combined to form space-filling networks, shaped for the required function. Basic structural components are highly modular, addressable arrays of robust nodes (tetrahedral apices) from which highly reconfigurable struts (tetrahedral edges), acting as supports or tethers, are efficiently reversibly deployed/stowed, transforming and reshaping the structures as required.

  20. Reconfiguration in Mobile Multimedia Systems

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Havinga, Paul J.M.; Bos, M.; Smit, L.T.; Heysters, P.M.

    2000-01-01

    Dynamically reconfigurable systems offer the potential for realising efficient systems as well as providing adaptability to changing system requirements. Such systems are suitable for future mobile multimedia systems that have limited battery resources, must handle diverse data types, and must

  1. Terrain Adaptive Reconfiguration of Mobility

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop an algorithm (and software) to automatically adapt a reconfigurable robot to different types of terrains for improved mobility, that compared to SOA:...

  2. Dynamic Reconfiguration in Planetary Exploration

    DEFF Research Database (Denmark)

    Cohn, Marisa

    2014-01-01

    In taking into account the ways in which material and social realms are constitutively entangled within organizations, it is rhetorically tempting to say that technologies and social structures reconfigure each other. But what does it mean to reconfigure? How does one "figure" the other and how do...... we fully embrace a mutually constitutive relationship when examining fluid relations? This paper delves into these questions by exploring how physical, social, material, technological, and organizational arrangements dynamically reconfigure each other in the duration of organizational practice. Using...... be gained by focusing attention on the dynamic reconfigurations between social and material realms. In so doing, we call attention to the ways in which current sociomaterial perspectives have difficulty articulating the shifting, figural, asymmetric and dynamic negotiations between people, social structures...

  3. Hybrid nanocomposites based on electroactive hydrogels and cellulose nanocrystals for high-sensitivity electro-mechanical underwater actuation

    Science.gov (United States)

    Santaniello, Tommaso; Migliorini, Lorenzo; Locatelli, Erica; Monaco, Ilaria; Yan, Yunsong; Lenardi, Cristina; Comes Franchini, Mauro; Milani, Paolo

    2017-08-01

    We report the synthesis, fabrication and characterization of a hybrid hydrogel/cellulose nanocomposite, which exhibits high-performance electro-mechanical underwater actuation and high sensitivity in response to electrical stimuli below the standard potential of water electrolysis. The macromolecular structure of the material is constituted by an electroactive hydrogel, obtained through a photo-polymerization reaction with the use of three vinylic co-monomers: Na-4-vinylbenzenesulfonate, 2-hydroxyethylmethacrylate, and acrylonitrile. Different amounts (from 0.1% to 1.4% w/w) of biodegradable cellulose nanocrystals (CNCs) with sulfonate surface groups, obtained through the acidic hydrolysis of sulphite pulp lapsheets, are physically incorporated into the gel matrix during the synthesis step. Freestanding thin films of the nanocomposites are molded, and their swelling, mechanical and responsive properties are fully characterized. We observed that the embedding of the CNCs enhanced both the material Young’s modulus and its sensitivity to the applied electric field in the sub-volt regime (down to 5 mV cm-1). A demonstrator integrating multiple actuators that cooperatively bend together, mimicking the motion of an electro-valve, is also prototyped and tested. The presented nanocomposite is suitable for the development of soft smart components for bio-robotic applications and cells-based and bio-hybrid fluidic devices fabrication.

  4. Actuators for smart applications

    NARCIS (Netherlands)

    Paternoster, Alexandre; de Boer, Andries; Loendersloot, Richard; Akkerman, Remko; D. Brei,; M. Frecker,

    2010-01-01

    Actuator manufacturers are developing promising technologies which meet high requirements in performance, weight and power consumption. Conventionally, actuators are characterized by their displacement and load performance. This hides the dynamic aspects of those actuation solutions. Work per weight

  5. A bidirectional shape memory alloy folding actuator

    International Nuclear Information System (INIS)

    Paik, Jamie K; Wood, Robert J

    2012-01-01

    This paper presents a low-profile bidirectional folding actuator based on annealed shape memory alloy sheets applicable for meso- and microscale systems. Despite the advantages of shape memory alloys—high strain, silent operation, and mechanical simplicity—their application is often limited to unidirectional operation. We present a bidirectional folding actuator that produces two opposing 180° motions. A laser-patterned nickel alloy (Inconel 600) heater localizes actuation to the folding sections. The actuator has a thin ( < 1 mm) profile, making it appropriate for use in robotic origami. Various design parameters and fabrication variants are described and experimentally explored in the actuator prototype. (paper)

  6. Firewater system inadvertent actuation frequencies

    International Nuclear Information System (INIS)

    Schroeder, J.A.; Eide, S.A.

    1993-01-01

    This paper presents some recommended generic values for fire protection system inadvertent actuation frequencies. The frequencies are based on actual data from Department of Energy and commercial reactor plant facilities

  7. Reconfigurable, Cognitive Software-Defined Radio

    Science.gov (United States)

    Bhat, Arvind

    2015-01-01

    Software-defined radio (SDR) technology allows radios to be reconfigured to perform different communication functions without using multiple radios to accomplish each task. Intelligent Automation, Inc., has developed SDR platforms that switch adaptively between different operation modes. The innovation works by modifying both transmit waveforms and receiver signal processing tasks. In Phase I of the project, the company developed SDR cognitive capabilities, including adaptive modulation and coding (AMC), automatic modulation recognition (AMR), and spectrum sensing. In Phase II, these capabilities were integrated into SDR platforms. The reconfigurable transceiver design employs high-speed field-programmable gate arrays, enabling multimode operation and scalable architecture. Designs are based on commercial off-the-shelf (COTS) components and are modular in nature, making it easier to upgrade individual components rather than redesigning the entire SDR platform as technology advances.

  8. Reconfigurable Manufacturing System Design and Implementation

    DEFF Research Database (Denmark)

    Hadar, Ronen; Bilberg, Arne

    2013-01-01

    is meant primarily to show the physical feasibility of the system and provide a first-look into a real production application of the RMS ideas. The purpose of this paper is to present the design of the manufacturer’s RMS proof of concept, its implementation, and evaluation results.......Reconfigurable Manufacturing Systems (RMS) have been an increasing area of interest in the research arena. However, it seems that current literature is lacking application and implementation cases where RMS are simulated, tested, and evaluated as a feasible manufacturing concept. A Manufacturer...... of Consumer Goods identified the potential of the RMS concept and decided to investigate the concept in a real production installation. The result of this development is a proof of concept of a changeable and reconfigurable assembly and decoration system based on the principles of RMS. This proof of concept...

  9. Distributed reconfigurable control strategies for switching topology networked multi-agent systems.

    Science.gov (United States)

    Gallehdari, Z; Meskin, N; Khorasani, K

    2017-11-01

    In this paper, distributed control reconfiguration strategies for directed switching topology networked multi-agent systems are developed and investigated. The proposed control strategies are invoked when the agents are subject to actuator faults and while the available fault detection and isolation (FDI) modules provide inaccurate and unreliable information on the estimation of faults severities. Our proposed strategies will ensure that the agents reach a consensus while an upper bound on the team performance index is ensured and satisfied. Three types of actuator faults are considered, namely: the loss of effectiveness fault, the outage fault, and the stuck fault. By utilizing quadratic and convex hull (composite) Lyapunov functions, two cooperative and distributed recovery strategies are designed and provided to select the gains of the proposed control laws such that the team objectives are guaranteed. Our proposed reconfigurable control laws are applied to a team of autonomous underwater vehicles (AUVs) under directed switching topologies and subject to simultaneous actuator faults. Simulation results demonstrate the effectiveness of our proposed distributed reconfiguration control laws in compensating for the effects of sudden actuator faults and subject to fault diagnosis module uncertainties and unreliabilities. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  10. V-stack piezoelectric actuator

    Science.gov (United States)

    Ardelean, Emil V.; Clark, Robert L.

    2001-07-01

    Aeroelastic control of wings by means of a distributed, trailing-edge control surface is of interest with regards to maneuvers, gust alleviation, and flutter suppression. The use of high energy density, piezoelectric materials as motors provides an appealing solution to this problem. A comparative analysis of the state of the art actuators is currently being conducted. A new piezoelectric actuator design is presented. This actuator meets the requirements for trailing edge flap actuation in both stroke and force. It is compact, simple, sturdy, and leverages stroke geometrically with minimum force penalties while displaying linearity over a wide range of stroke. The V-Stack Piezoelectric Actuator, consists of a base, a lever, two piezoelectric stacks, and a pre-tensioning element. The work is performed alternately by the two stacks, placed on both sides of the lever. Pre-tensioning can be readily applied using a torque wrench, obviating the need for elastic elements and this is for the benefit of the stiffness of the actuator. The characteristics of the actuator are easily modified by changing the base or the stacks. A prototype was constructed and tested experimentally to validate the theoretical model.

  11. Silicon-based micromembranes with piezoelectric actuation and piezoresistive detection for sensing purposes in liquid media

    International Nuclear Information System (INIS)

    Alava, T; Mathieu, F; Mazenq, L; Nicu, L; Soyer, C; Remiens, D

    2010-01-01

    In this paper, the authors report for the first time the physical cointegration of piezoelectric actuation and piezoresistive detection on resonating micromembranes dedicated to microgravimetric biosensing applications. The micromembranes are oscillated by a reverse piezoelectric phenomenon provided by a PbZr x Ti 1−x O 3 46/54 thin layer. The oscillation amplitudes are read-out by measuring the resistance change of piezoresistors precisely located on the clamped edges of each micromembrane. The detection of the micromembranes' resonant frequencies is reported in air and deionized water. A dedicated electronic set-up operating the micromembranes in a closed-loop configuration is described. The set-up enables multiplexed tracking of four micromembranes' resonant frequencies in liquid media while enhancing the corresponding quality factors' values. Increases up to 11-fold of the micromembranes' quality factors in liquid is reported for the (0,1) vibration mode. A quality factor of up to 417 is reported in fluid.

  12. Optimization Method of Intersection Signal Coordinated Control Based on Vehicle Actuated Model

    Directory of Open Access Journals (Sweden)

    Chen Zhao-Meng

    2015-01-01

    Full Text Available Traditional timing green wave control with predetermined cycle, split, and offset cannot adapt for dynamic real-time traffic flow. This paper proposes a coordinated control method for variable cycle time green wave bandwidth optimization integrated with traffic-actuated control. In the coordinated control, green split is optimized in real time by the measured presence of arriving and/or standing vehicles in each intersection and simultaneously green waves along arterials are guaranteed. Specifically, the dynamic bound of green wave is firstly determined, and then green early-start and green late-start algorithms are presented respectively to accommodate the fluctuations in vehicle arrival rates in each phase. Numerical examples show that the proposed method improves green time, expands green wave bandwidth, and reduces queuing.

  13. MEMS-based thermally-actuated image stabilizer for cellular phone camera

    International Nuclear Information System (INIS)

    Lin, Chun-Ying; Chiou, Jin-Chern

    2012-01-01

    This work develops an image stabilizer (IS) that is fabricated using micro-electro-mechanical system (MEMS) technology and is designed to counteract the vibrations when human using cellular phone cameras. The proposed IS has dimensions of 8.8 × 8.8 × 0.3 mm 3 and is strong enough to suspend an image sensor. The processes that is utilized to fabricate the IS includes inductive coupled plasma (ICP) processes, reactive ion etching (RIE) processes and the flip-chip bonding method. The IS is designed to enable the electrical signals from the suspended image sensor to be successfully emitted out using signal output beams, and the maximum actuating distance of the stage exceeds 24.835 µm when the driving current is 155 mA. Depending on integration of MEMS device and designed controller, the proposed IS can decrease the hand tremor by 72.5%. (paper)

  14. Context-Based Filtering for Assisted Brain-Actuated Wheelchair Driving

    Directory of Open Access Journals (Sweden)

    Gerolf Vanacker

    2007-01-01

    Full Text Available Controlling a robotic device by using human brain signals is an interesting and challenging task. The device may be complicated to control and the nonstationary nature of the brain signals provides for a rather unstable input. With the use of intelligent processing algorithms adapted to the task at hand, however, the performance can be increased. This paper introduces a shared control system that helps the subject in driving an intelligent wheelchair with a noninvasive brain interface. The subject's steering intentions are estimated from electroencephalogram (EEG signals and passed through to the shared control system before being sent to the wheelchair motors. Experimental results show a possibility for significant improvement in the overall driving performance when using the shared control system compared to driving without it. These results have been obtained with 2 healthy subjects during their first day of training with the brain-actuated wheelchair.

  15. Capacitive sensing of droplets for microfluidic devices based on thermocapillary actuation.

    Science.gov (United States)

    Chen, Jian Z; Darhuber, Anton A; Troian, Sandra M; Wagner, Sigurd

    2004-10-01

    The design and performance of a miniaturized coplanar capacitive sensor is presented whose electrode arrays can also function as resistive microheaters for thermocapillary actuation of liquid films and droplets. Optimal compromise between large capacitive signal and high spatial resolution is obtained for electrode widths comparable to the liquid film thickness measured, in agreement with supporting numerical simulations which include mutual capacitance effects. An interdigitated, variable width design, allowing for wider central electrodes, increases the capacitive signal for liquid structures with non-uniform height profiles. The capacitive resolution and time response of the current design is approximately 0.03 pF and 10 ms, respectively, which makes possible a number of sensing functions for nanoliter droplets. These include detection of droplet position, size, composition or percentage water uptake for hygroscopic liquids. Its rapid response time allows measurements of the rate of mass loss in evaporating droplets.

  16. Advances in Reconfigurable Mechanisms and Robots I

    CERN Document Server

    Zoppi, Matteo; Kong, Xianwen

    2012-01-01

    Advances in Reconfigurable Mechanisms and Robots I provides a selection of key papers presented in The Second ASME/IFToMM International Conference on Reconfigurable Mechanisms and Robots (ReMAR 2012) held on 9th -11th  July 2012 in Tianjin, China. This ongoing series of conferences will be covered in this ongoing collection of books.   A total of seventy-eight papers are divided into seven parts to cover the topology, kinematics and design of reconfigurable mechanisms with the reconfiguration theory, analysis and synthesis, and present the current research and development in the field of reconfigurable mechanisms including reconfigurable parallel mechanisms. In this aspect, the recent study and development of reconfigurable robots are further presented with the analysis and design and with their control and development. The bio-inspired mechanisms and subsequent reconfiguration are explored in the challenging fields of rehabilitation and minimally invasive surgery. Advances in Reconfigurable Mechanisms and ...

  17. Epoxy-Based Shape-Memory Actuators Obtained via Dual-Curing of Off-Stoichiometric “Thiol–Epoxy” Mixtures

    Directory of Open Access Journals (Sweden)

    Alberto Belmonte

    2017-03-01

    Full Text Available In this work, epoxy-based shape-memory actuators have been developed by taking advantage of the sequential dual-curing of off-stoichiometric “thiol–epoxy” systems. Bent-shaped designs for flexural actuation were obtained thanks to the easy processing of these materials in the intermediate stage (after the first curing process, and successfully fixed through the second curing process. The samples were programmed into a flat temporary-shape and the recovery-process was analyzed in unconstrained, partially-constrained and fully-constrained conditions using a dynamic mechanical analyzer (DMA. Different “thiol–epoxy” systems and off-stoichiometric ratios were used to analyze the effect of the network structure on the actuation performance. The results evidenced the possibility to take advantage of the flexural recovery as a potential actuator, the operation of which can be modulated by changing the network structure and properties of the material. Under unconstrained-recovery conditions, faster and narrower recovery-processes (an average speed up to 80%/min are attained by using materials with homogeneous network structure, while in partially- or fully-constrained conditions, a higher crosslinking density and the presence of crosslinks of higher functionality lead to a higher amount of energy released during the recovery-process, thus, increasing the work or the force released. Finally, an easy approach for the prediction of the work released by the shape-memory actuator has been proposed.

  18. Rational design of reconfigurable prismatic architected materials

    Science.gov (United States)

    Overvelde, Johannes T. B.; Weaver, James C.; Hoberman, Chuck; Bertoldi, Katia

    2017-01-01

    Advances in fabrication technologies are enabling the production of architected materials with unprecedented properties. Most such materials are characterized by a fixed geometry, but in the design of some materials it is possible to incorporate internal mechanisms capable of reconfiguring their spatial architecture, and in this way to enable tunable functionality. Inspired by the structural diversity and foldability of the prismatic geometries that can be constructed using the snapology origami technique, here we introduce a robust design strategy based on space-filling tessellations of polyhedra to create three-dimensional reconfigurable materials comprising a periodic assembly of rigid plates and elastic hinges. Guided by numerical analysis and physical prototypes, we systematically explore the mobility of the designed structures and identify a wide range of qualitatively different deformations and internal rearrangements. Given that the underlying principles are scale-independent, our strategy can be applied to the design of the next generation of reconfigurable structures and materials, ranging from metre-scale transformable architectures to nanometre-scale tunable photonic systems.

  19. Dynamic pull-in instability of geometrically nonlinear actuated micro-beams based on the modified couple stress theory

    Directory of Open Access Journals (Sweden)

    Hamid M. Sedighi

    Full Text Available This paper investigates the dynamic pull-in instability of vibrating micro-beams undergoing large deflection under electrosatically actuation. The governing equation of motion is derived based on the modified couple stress theory. Homotopy Perturbation Method is employed to produce the high accuracy approximate solution as well as the second-order frequency- amplitude relationship. The nonlinear governing equation of micro beam vibrations predeformed by an electric field includes both even and odd nonlinearities. The influences of basic non-dimensional parameters on the pull-in instability as well as the natural frequency are studied. It is demonstrated that two terms in series expansions are sufficient to produce high accuracy solution of the micro-structure. The accuracy of proposed asymptotic approach is validated via numerical results. The phase portrait of the system exhibits periodic and homoclinic orbits.

  20. Improvement of fatigue resistance for multilayer lead zirconate titanate (PZT)-based ceramic actuators by external mechanical loads

    Science.gov (United States)

    Yang, Gang; Yue, Zhenxing; Ji, Ye; Chu, Xiangcheng; Li, Longtu

    2008-12-01

    The influence of external compressive loads, applied along a direction perpendicular to polarization, on fatigue behaviors of multilayer lead zirconate titanate (PZT)-based ceramic actuators was investigated. Under no external mechanical load, a normal fatigue behavior was observed, demonstrating that both switching polarization (Pswitching) and remnant polarization (Pr) progressively decreased with increasing switching cycles due to domain pinning by charge point defects. However, an anomalous enhancement in both switching and remnant polarizations was observed upon application of the external compressive loads. After 5×106 cycles of polarization switching, Pswitching and Pr increase by about 13% and 6% at 40 MPa, respectively, while Pswitching and Pr increase by about 11% and 21% at 60 MPa, respectively. The improvement of fatigue resistance can be attributed to non-180° domain switching and suppression of microcracking, triggered by external mechanical loads.

  1. Ion-Selective Ionic Polymer Metal Composite (IPMC) actuator based on crown ether containing sulfonated Poly(Arylene Ether Ketone)

    NARCIS (Netherlands)

    Tas, S.; Zoetebier, B.; Sukas, O.S.; Bayraktar, M.; Hempenius, M.; Vancso, G.J.; Nijmeijer, K.

    2017-01-01

    This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane

  2. Dynamic reconfiguration of van der Waals gaps within GeTe-Sb2Te3 based superlattices

    NARCIS (Netherlands)

    Momand, Jamo; Wang, Ruining; Boschker, Jos E.; Verheijen, Marcel A.; Calarco, Raffaella; Kooi, Bart J.

    2017-01-01

    Phase-change materials based on GeSbTe show unique switchable optoelectronic properties and are an important contender for next-generation non-volatile memories. Moreover, they recently received considerable scientific interest, because it is found that a vacancy ordering process is responsible for

  3. Dynamic reconfiguration of van der Waals gaps within GeTe-Sb2-Te3 based superlattices

    NARCIS (Netherlands)

    Momand, J.; Wang, R.; Boschker, J.E.; Verheijen, M.A.; Calarco, R.; Kooi, B.J.

    2017-01-01

    Phase-change materials based on GeSbTe show unique switchable optoelectronic properties and are an important contender for next-generation non-volatile memories. Moreover, they recently received considerable scientific interest, because it is found that a vacancy ordering process is responsible for

  4. An Electrically Actuated Microbeam-Based MEMS Device: Experimental and Theoretical Investigation

    KAUST Repository

    Ruzziconi, Laura

    2017-11-03

    The present paper deals with the dynamic behavior of a microelectromechanical systems (MEMS). The device consists of a clamped-clamped microbeam electrostatically and electrodynamically actuated. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. In the first part of the paper an extensive experimental investigation is conducted. The microbeam is perfectly straight. The first three experimental natural frequencies are identified and the nonlinear dynamics are explored at increasing values of electrodynamic excitation. Several backward and forward frequency sweeps are acquired. The nonlinear behavior is highlighted. The experimental data show the coexistence of the nonresonant and the resonant branch, which perform a bending toward higher frequencies values before undergoing jump or pull-in dynamics. This kind of bending is not particularly common in MEMS. In the second part of the paper, a theoretical single degree-of-freedom model is derived. The unknown parameters are extracted and settled via parametric identification. A single mode reduced-order model is considered, which is obtained via the Galerkin technique. To enhance the computational efficiency, the contribution of the electric force term is computed in advance and stored in a table. Extensive numerical simulations are performed at increasing values of electrodynamic excitation. They are observed to properly predict all the main nonlinear features arising in the device response. This occurs not only at low values of electrodynamic excitation, but also at higher ones

  5. Adaptive observer-based control for an IPMC actuator under varying humidity conditions

    Science.gov (United States)

    Bernat, Jakub; Kolota, Jakub

    2018-05-01

    As ionic polymer metal composites (IPMC) are increasingly applied to mechatronic systems, many new IPMC modeling efforts have been reported in the literature. The demands of rapidly growing technology has generated interest in advancing the intrinsic actuation and sensing capabilities of IPMC. Classical IPMC applications need constant hydration to operate. On the other hand, for IPMCs operating in air, the water content of the polymer varies with the humidity level of the ambient environment, which leads to its strong humidity-dependent behavior. Furthermore, decreasing water content over time plays a crucial role in the effectiveness of IPMC. Therefore, the primary challenge of this work is to accurately model this phenomenon. The principal contribution of the paper is a new IPMC model, which considers the change of moisture content. A novel nonlinear adaptive observer is designed to determine the unknown electric potential and humidity level in the polymer membrane. This approach effectively determines the moisture content of the IPMC during long-term continuous operation in air. This subsequently allows us to develop an effective back-stepping control algorithm that considers varying moisture content. Data from experiments are presented to support the effectiveness of the observation process, which is shown in illustrative examples.

  6. Dielectric Actuation of Polymers

    Science.gov (United States)

    Niu, Xiaofan

    in tactile display is investigated by the prototyping of a large scale refreshable Braille display device. Braille is a critical way for the vision impaired community to learn literacy and improve life quality. Current piezoelectrics-based refreshable Braille display technologies are limited to up to 1 line of Braille text, due to the bulky size of bimorph actuators. Based on the unique actuation feature of BSEP, refreshable Braille display devices up to smartphone-size have been demonstrated by polymer sheet laminates. Dots in the devices can be individually controlled via incorporated field-driven BSEP actuators and Joule heater units. A composite material consisting of silver nanowires (AgNW) embedded in a polymer substrate is brought up as a compliant electrode candidate for BSEP application. The AgNW composite is highly conductive (Rs: 10 Ω/sq) and remains conductive at strains as high as 140% (Rs: <10 3 Ω/sq). The baseline conductivity has only small changes up to 90% strain, which makes it low enough for both field driving and stretchable Joule heating. An out-of-plane bistable area strain up to 68% under Joule heating is achieved.

  7. Dessign and Implementation of Hardened Reconfiguration Controller for Self-Healing Systems on SRAM-Based FPGAs

    OpenAIRE

    DERAKHSHAN, NASER

    2013-01-01

    As digital systems become large and complex, their dependability is getting more important, particularly in mission-critical and safety‐critical applications. Among various available platforms for implementing a digital system, SRAM-based Field Programmable Gate Arrays (FPGAs) are increasingly adopted in embedded systems due to their flexibility in achieving multiple requirements such as low cost, high performance, and fast turnaround time compared to Fixed Application Specific Integrated Cir...

  8. A Modular Re-configurable Rover System

    Science.gov (United States)

    Bouloubasis, A.; McKee, G.; Active Robotics Lab

    In this paper we present the novel concepts incorporated in a planetary surface exploration rover design that is currently under development. The Multitasking Rover (MTR) aims to demonstrate functionality that will cover many of the current and future needs such as rough-terrain mobility, modularity and upgradeability [1]. The rover system has enhanced mobility characteristics. It operates in conjunction with Science Packs (SPs) and Tool Packs (TPs) - modules attached to the main frame of the rover, which are either special tools or science instruments and alter the operation capabilities of the system. To date, each rover system design is very much task driven for example, the scenario of cooperative transportation of extended payloads [2], comprises two rovers each equipped with a manipulator dedicated to the task [3]. The MTR approach focuses mostly on modularity and upgradeability presenting at the same time a fair amount of internal re-configurability for the sake of rough terrain stability. The rover itself does not carry any scientific instruments or tools. To carry out the scenario mentioned above, the MTR would have to locate and pick-up a TP with the associated manipulator. After the completion of the task the TP could be put away to a storage location enabling the rover to utilize a different Pack. The rover will not only offer mobility to these modules, but also use them as tools, transforming its role and functionality. The advantage of this approach is that instead of sending a large number of rovers to perform a variety of tasks, a smaller number of MTRs could be deployed with a large number of SPs/TPs, offering multiples of the functionality at a reduced payload. Two SPs or TPs (or a combination of) can be carried and deployed. One of the key elements in the design of the four wheeled rover, lies within its suspension system. It comprises a linear actuator located within each leg and also an active differential linking the two shoulders. This novel

  9. A micro-optical system for endoscopy based on mechanical compensation paradigm using miniature piezo-actuation.

    Science.gov (United States)

    Cerveri, Pietro; Zazzarini, Cynthia Corinna; Patete, Paolo; Baroni, Guido

    2014-06-01

    The goal of the study was to investigate the feasibility of a novel miniaturized optical system for endoscopy. Fostering the mechanical compensation paradigm, the modeled optical system, composed by 14 lenses, separated in 4 different sets, had a total length of 15.55mm, an effective focal length ranging from 1.5 to 4.5mm with a zoom factor of about 2.8×, and an angular field of view up to 56°. Predicted maximum lens travel was less than 3.5mm. The consistency of the image plane height across the magnification range testified the zoom capability. The maximum predicted achromatic astigmatism, transverse spherical aberration, longitudinal spherical aberration and relative distortion were less than or equal to 25μm, 15μm, 35μm and 12%, respectively. Tests on tolerances showed that the manufacturing and opto-mechanics mounting are critical as little deviations from design dramatically decrease the optical performances. However, recent micro-fabrication technology can guarantee tolerances close to nominal design. A closed-loop actuation unit, devoted to move the zoom and the focus lens sets, was implemented adopting miniaturized squiggle piezo-motors and magnetic position encoders based on Hall effect. Performance results, using a prototypical test board, showed a positioning accuracy of less than 5μm along a lens travel path of 4.0mm, which was in agreement with the lens set motion features predicted by the analysis. In conclusion, this study demonstrated the feasibility of the optical design and the viability of the actuation approach while tolerances must be carefully taken into account. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  10. Piezoelectric actuator based phase locking system to improve the dynamics of the control scheme for a heavy ion superconducting linac

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, B.K., E-mail: bhuban@iuac.res.in [Inter University Accelerator Centre (IUAC), Aruna Asaf Ali Marg, New Delhi – 110 067 (India); Ahuja, R.; Kumar, Rajesh; Suman, S.K.; Mathuria, D.S.; Rai, A.; Patra, P.; Pandey, A.; Karmakar, J.; Chowdhury, G.K.; Dutt, R.N. [Inter University Accelerator Centre (IUAC), Aruna Asaf Ali Marg, New Delhi – 110 067 (India); Joshi, G. [Electronics Division, Bhabha Atomic Research Centre, Mumbai – 400 085 (India); Ghosh, S.; Kanjilal, D.; Roy, A. [Inter University Accelerator Centre (IUAC), Aruna Asaf Ali Marg, New Delhi – 110 067 (India)

    2015-03-21

    The superconducting heavy ion linear accelerator at Inter-University Accelerator Centre Delhi has been in operation since 2007. Initially, the superconducting niobium Quarter Wave Resonators (QWRs) in the linac were phase locked using a combination of electronic and mechanical controls which operated in fast (~10 μsec) and slow (~sec) time scales respectively. In this scheme, fast control was achieved through dynamic phase control whereas slow control of the frequency was done through the niobium tuner bellows installed at the drift tube end of the resonator and flexed using helium gas to change the resonance frequency. In order to improve the dynamics of this control system, an alternate scheme using piezoelectric actuator, instead of helium gas, to flex the same niobium bellows, has been implemented in the QWRs of the second and third accelerating modules of the linac. The piezoelectric actuator is used in closed loop along with the fast dynamic phase control scheme. The feedback loop of the piezoelectric control includes a dual control scheme - an integral control loop to arrest the slow drift, and the positive position feedback (PPF) based control loop to damp the microphonics. This control scheme has been found to arrest slow drifts in the resonator frequency more tightly along with damping of low frequency microphonics (~few tens of Hz) picked up by the resonator from its surrounding environment. This has substantially eased the load from the fast electronic control, resulting in the reduction of the radio frequency (RF) power requirement during operation. In addition, it has improved the stability of phase and amplitude of the QWRs. The details of the new scheme along with results obtained during the online run of the linac for beam acceleration are presented.

  11. Modular and reconfigurable common PCB-platform of FPGA based LLRF control system for TESLA test facility

    Energy Technology Data Exchange (ETDEWEB)

    Pozniak, K.T.; Romaniuk, R.S. [Institute of Electronic Systems, Warsaw (Poland); Kierzkowski, K. [Institute of Experimental Physics, Warsaw (Poland)

    2005-07-01

    The paper includes a description of predicted functionalities to be implemented in a universal motherboard (MB) for the next generation of LLRF control system for TESLA. The motherboard bases on a number of quasi-autonomous embedded executive modules. The modules are implemented in a few FPGA chips featured by the MB. The paper presents a practical design of the MB. The initial (basic) solution of the MB has the Cyclone as the chip where the board management is embedded. The board features communication modules - VME and micro, single chip PC with Ethernet. The board provides power supply for the FPGA chips. The board has fast internal communication between particular modules. (orig.)

  12. Modular and reconfigurable common PCB-platform of FPGA based LLRF control system for TESLA test facility

    International Nuclear Information System (INIS)

    Pozniak, K.T.; Romaniuk, R.S.; Kierzkowski, K.

    2005-01-01

    The paper includes a description of predicted functionalities to be implemented in a universal motherboard (MB) for the next generation of LLRF control system for TESLA. The motherboard bases on a number of quasi-autonomous embedded executive modules. The modules are implemented in a few FPGA chips featured by the MB. The paper presents a practical design of the MB. The initial (basic) solution of the MB has the Cyclone as the chip where the board management is embedded. The board features communication modules - VME and micro, single chip PC with Ethernet. The board provides power supply for the FPGA chips. The board has fast internal communication between particular modules. (orig.)

  13. Flight control actuation system

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Gaines, Louie T. (Inventor); Evans, Paul S. (Inventor); Kern, James I. (Inventor)

    2006-01-01

    A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.

  14. Resource optimised reconfigurable modular parallel pipelined stochastic approximation-based self-tuning regulator architecture with reduced latency

    Directory of Open Access Journals (Sweden)

    Varghese Mathew Vaidyan

    2015-09-01

    Full Text Available Present self-tuning regulator architectures based on recursive least-square estimation are computationally expensive and require large amount of resources and time in generating the first control signal due to computational bottlenecks imposed by the calculations involved in estimation stage, different stages of matrix multiplications and the number of intermediate variables at each iteration and precludes its use in applications that have fast required response times and those which run on embedded computing platforms with low-power or low-cost requirements with constraints on resource usage. A salient feature of this study is that a new modular parallel pipelined stochastic approximation-based self-tuning regulator architecture which reduces the time required to generate the first control signal, reduces resource usage and reduces the number of intermediate variables is proposed. Fast matrix multiplication, pipelining and high-speed arithmetic function implementations were used for improving the performance. Results of implementation demonstrate that the proposed architecture has an improvement in control signal generation time by 38% and reduction in resource usage by 41% in terms of multipliers and 44.4% in terms of adders compared with the best existing related work, opening up new possibilities for the application of online embedded self-tuning regulators.

  15. Generalized Boolean logic Driven Markov Processes: A powerful modeling framework for Model-Based Safety Analysis of dynamic repairable and reconfigurable systems

    International Nuclear Information System (INIS)

    Piriou, Pierre-Yves; Faure, Jean-Marc; Lesage, Jean-Jacques

    2017-01-01

    This paper presents a modeling framework that permits to describe in an integrated manner the structure of the critical system to analyze, by using an enriched fault tree, the dysfunctional behavior of its components, by means of Markov processes, and the reconfiguration strategies that have been planned to ensure safety and availability, with Moore machines. This framework has been developed from BDMP (Boolean logic Driven Markov Processes), a previous framework for dynamic repairable systems. First, the contribution is motivated by pinpointing the limitations of BDMP to model complex reconfiguration strategies and the failures of the control of these strategies. The syntax and semantics of GBDMP (Generalized Boolean logic Driven Markov Processes) are then formally defined; in particular, an algorithm to analyze the dynamic behavior of a GBDMP model is developed. The modeling capabilities of this framework are illustrated on three representative examples. Last, qualitative and quantitative analysis of GDBMP models highlight the benefits of the approach.

  16. Soft Pneumatic Actuators for Rehabilitation

    Directory of Open Access Journals (Sweden)

    Guido Belforte

    2014-05-01

    Full Text Available Pneumatic artificial muscles are pneumatic devices with practical and various applications as common actuators. They, as human muscles, work in agonistic-antagonistic way, giving a traction force only when supplied by compressed air. The state of the art of soft pneumatic actuators is here analyzed: different models of pneumatic muscles are considered and evolution lines are presented. Then, the use of Pneumatic Muscles (PAM in rehabilitation apparatus is described and the general characteristics required in different applications are considered, analyzing the use of proper soft actuators with various technical properties. Therefore, research activity carried out in the Department of Mechanical and Aerospace Engineering in the field of soft and textile actuators is presented here. In particular, pneumatic textile muscles useful for active suits design are described. These components are made of a tubular structure, with an inner layer of latex coated with a deformable outer fabric sewn along the edge. In order to increase pneumatic muscles forces and contractions Braided Pneumatic Muscles are studied. In this paper, new prototypes are presented, based on a fabric construction and various kinds of geometry. Pressure-force-deformation tests results are carried out and analyzed. These actuators are useful for rehabilitation applications. In order to reproduce the whole upper limb movements, new kind of soft actuators are studied, based on the same principle of planar membranes deformation. As an example, the bellows muscle model and worm muscle model are developed and described. In both cases, wide deformations are expected. Another issue for soft actuators is the pressure therapy. Some textile sleeve prototypes developed for massage therapy on patients suffering of lymph edema are analyzed. Different types of fabric and assembly techniques have been tested. In general, these Pressure Soft Actuators are useful for upper/lower limbs treatments

  17. Design of a hybrid reconfigurable Software Defined Radio transceiver based on frequency shift keying using multiple encoding schemes

    Directory of Open Access Journals (Sweden)

    Nikhil Marriwala

    2016-03-01

    The aim of this paper was to analyze Frequency Shift Keying (FSK Transceiver built using Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW and to measure the reduction in data errors in the presence of Forward Error Correction (FEC channel coding algorithms namely the Convolution and the Turbo Codes. Through this design a graphical representation of Bit Error Rate (BER vs Eb/N0 where (Eb is Energy per bit and (N0 is Spectral noise density has been given in the presence of Additive White Gaussian Noise (AWGN introduced in the channel. FSK is widely used for data transmission over band pass channels; hence, we have chosen FSK for the implementation of SDR. The SDR transceiver module designed has been fully implemented and has the ability to navigate over a wide range of frequencies with programmable channel bandwidth and modulation characteristics. We are able to build an interactive FSK based SDR transceiver in a shorter time with the use of LabVIEW. The outputs achieved show a low BER for very high data rates in the presence of AWGN noise.

  18. Reconfiguring health workforce: a case-based comparative study explaining the increasingly diverse professional roles in Europe

    Directory of Open Access Journals (Sweden)

    Antoinette de Bont

    2016-11-01

    Full Text Available Abstract Background Over the past decade the healthcare workforce has diversified in several directions with formalised roles for health care assistants, specialised roles for nurses and technicians, advanced roles for physician associates and nurse practitioners and new professions for new services, such as case managers. Hence the composition of health care teams has become increasingly diverse. The exact extent of this diversity is unknown across the different countries of Europe, as are the drivers of this change. The research questions guiding this study were: What extended professional roles are emerging on health care teams? How are extended professional roles created? What main drivers explain the observed differences, if any, in extended roles in and between countries? Methods We performed a case-based comparison of the extended roles in care pathways for breast cancer, heart disease and type 2 diabetes. We conducted 16 case studies in eight European countries, including in total 160 interviews with physicians, nurses and other health care professionals in new roles and 600+ hours of observation in health care clinics. Results The results show a relatively diverse composition of roles in the three care pathways. We identified specialised roles for physicians, extended roles for nurses and technicians, and independent roles for advanced nurse practitioners and physician associates. The development of extended roles depends upon the willingness of physicians to delegate tasks, developments in medical technology and service (redesign. Academic training and setting a formal scope of practice for new roles have less impact upon the development of new roles. While specialised roles focus particularly on a well-specified technical or clinical domain, the generic roles concentrate on organising and integrating care and cure. Conclusion There are considerable differences in the number and kind of extended roles between both countries and care

  19. The VIPER project (Visualization Integration Platform for Exploration Research): a biologically inspired autonomous reconfigurable robotic platform for diverse unstructured environments

    Science.gov (United States)

    Schubert, Oliver J.; Tolle, Charles R.

    2004-09-01

    Over the last decade the world has seen numerous autonomous vehicle programs. Wheels and track designs are the basis for many of these vehicles. This is primarily due to four main reasons: a vast preexisting knowledge base for these designs, energy efficiency of power sources, scalability of actuators, and the lack of control systems technologies for handling alternate highly complex distributed systems. Though large efforts seek to improve the mobility of these vehicles, many limitations still exist for these systems within unstructured environments, e.g. limited mobility within industrial and nuclear accident sites where existing plant configurations have been extensively changed. These unstructured operational environments include missions for exploration, reconnaissance, and emergency recovery of objects within reconfigured or collapsed structures, e.g. bombed buildings. More importantly, these environments present a clear and present danger for direct human interactions during the initial phases of recovery operations. Clearly, the current classes of autonomous vehicles are incapable of performing in these environments. Thus the next generation of designs must include highly reconfigurable and flexible autonomous robotic platforms. This new breed of autonomous vehicles will be both highly flexible and environmentally adaptable. Presented in this paper is one of the most successful designs from nature, the snake-eel-worm (SEW). This design implements shape memory alloy (SMA) actuators which allow for scaling of the robotic SEW designs from sub-micron scale to heavy industrial implementations without major conceptual redesigns as required in traditional hydraulic, pneumatic, or motor driven systems. Autonomous vehicles based on the SEW design posses the ability to easily move between air based environments and fluid based environments with limited or no reconfiguration. Under a SEW designed vehicle, one not only achieves vastly improved maneuverability within a

  20. Control of Adjustable Compliant Actuators

    Directory of Open Access Journals (Sweden)

    Berno J.E. Misgeld

    2014-05-01

    Full Text Available Adjustable compliance or variable stiffness actuators comprise an additional element to elastically decouple the actuator from the load and are increasingly applied to human-centered robotic systems. The advantages of such actuators are of paramount importance in rehabilitation robotics, where requirements demand safe interaction between the therapy system and the patient. Compliant actuator systems enable the minimization of large contact forces arising, for example, from muscular spasticity and have the ability to periodically store and release energy in cyclic movements. In order to overcome the loss of bandwidth introduced by the elastic element and to guarantee a higher range in force/torque generation, new actuator designs consider variable or nonlinear stiffness elements, respectively. These components cannot only be adapted to the walking speed or the patient condition, but also entail additional challenges for feedback control. This paper introduces a novel design method for an impedance-based controller that fulfills the control objectives and compares the performance and robustness to a classical cascaded control approach. The new procedure is developed using a non-standard positive-real Η2 controller design and is applied to a loop-shaping approach. Robust norm optimal controllers are designed with regard to the passivity of the actuator load-impedance transfer function and the servo control problem. Classical cascaded and positive-real Η2 controller designs are validated and compared in simulations and in a test bench using a passive elastic element of varying stiffness.

  1. RECONFIGURACIÓN DE REDES ELÉCTRICAS DE MEDIA TENSIÓN BASADA EN EL ALGORITMO DE PRIM RECONFIGURATION OF MEDIUM VOLTAGE NETWORKS BASED ON PRIM'S ALGORITHM

    Directory of Open Access Journals (Sweden)

    Angely Cárcamo-Gallardo

    2007-04-01

    Full Text Available En este trabajo se presenta un nuevo algoritmo que permite reconfigurar un sistema de distribución (SD de energía eléctrica minimizando la energía no suministrada (ENS. El SD se modela utilizando teoría de grafos, mientras que la ENS se formula recursivamente y se parametriza en términos de los índices de confiabilidad del SD. Empleando esta modelación se transforma el problema de optimización en el problema de encontrar el árbol de mínima expansión (AME a partir del grafo que modela al SD, donde la métrica de distancia utilizada corresponde a la ENS a cada nodo del SD. Para encontrar de manera eficiente el AME se utiliza el algoritmo de Prim, ya que pertenece a la clase de algoritmos voraces en el cálculo del AME. Adicionalmente, se propone un algoritmo que realiza una revisión del AME obtenido analizando las topologías que fueron descartadas aleatoriamente durante el proceso de decisión. El desempeño del algoritmo de optimización se evalúa en sistemas de pruebas y en dos sistemas eléctricos reales.This paper presents a novel algorithm to reconfigure an electric power distribution network (EPDN, minimizing its non-supplied energy (NSE. The EPDN is modeled using graph theory and the NSE is recursively formulated in terms of the reliability parameters of the EPDN. Based on this mathematical model, we transform the original optimization problem into the graph theory problem of finding the minimum spanning tree (MST of a given graph, which models the EPDN. The distance metric employed by the searching algorithm is the NSE. In order to efficiently find the MST, Prim's algorithm is employed due to is greedy search behavior. In addition, a backtracking algorithm is used to check the MST obtained. The backtracking algorithm analyzes all the candidate topologies that were randomly discarded during the decision process. The performance of the optimization algorithm is evaluated using testing systems and two actual EPDNs.

  2. Smart Sound Processing for Defect Sizing in Pipelines Using EMAT Actuator Based Multi-Frequency Lamb Waves

    Directory of Open Access Journals (Sweden)

    Joaquín García-Gómez

    2018-03-01

    Full Text Available Pipeline inspection is a topic of particular interest to the companies. Especially important is the defect sizing, which allows them to avoid subsequent costly repairs in their equipment. A solution for this issue is using ultrasonic waves sensed through Electro-Magnetic Acoustic Transducer (EMAT actuators. The main advantage of this technology is the absence of the need to have direct contact with the surface of the material under investigation, which must be a conductive one. Specifically interesting is the meander-line-coil based Lamb wave generation, since the directivity of the waves allows a study based in the circumferential wrap-around received signal. However, the variety of defect sizes changes the behavior of the signal when it passes through the pipeline. Because of that, it is necessary to apply advanced techniques based on Smart Sound Processing (SSP. These methods involve extracting useful information from the signals sensed with EMAT at different frequencies to obtain nonlinear estimations of the depth of the defect, and to select the features that better estimate the profile of the pipeline. The proposed technique has been tested using both simulated and real signals in steel pipelines, obtaining good results in terms of Root Mean Square Error (RMSE.

  3. Smart Sound Processing for Defect Sizing in Pipelines Using EMAT Actuator Based Multi-Frequency Lamb Waves.

    Science.gov (United States)

    García-Gómez, Joaquín; Gil-Pita, Roberto; Rosa-Zurera, Manuel; Romero-Camacho, Antonio; Jiménez-Garrido, Jesús Antonio; García-Benavides, Víctor

    2018-03-07

    Pipeline inspection is a topic of particular interest to the companies. Especially important is the defect sizing, which allows them to avoid subsequent costly repairs in their equipment. A solution for this issue is using ultrasonic waves sensed through Electro-Magnetic Acoustic Transducer (EMAT) actuators. The main advantage of this technology is the absence of the need to have direct contact with the surface of the material under investigation, which must be a conductive one. Specifically interesting is the meander-line-coil based Lamb wave generation, since the directivity of the waves allows a study based in the circumferential wrap-around received signal. However, the variety of defect sizes changes the behavior of the signal when it passes through the pipeline. Because of that, it is necessary to apply advanced techniques based on Smart Sound Processing (SSP). These methods involve extracting useful information from the signals sensed with EMAT at different frequencies to obtain nonlinear estimations of the depth of the defect, and to select the features that better estimate the profile of the pipeline. The proposed technique has been tested using both simulated and real signals in steel pipelines, obtaining good results in terms of Root Mean Square Error (RMSE).

  4. Single Crystal Piezoelectric Stack Actuator DM with Integrated Low-Power HVA-Based Driver ASIC, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project aims to develop an innovative batch fabrication technique to create single crystal PMN-PT stack actuator deformable mirrors (DM) at low...

  5. Dynamic Reconfiguration in Mobile Systems

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Glesner, Manfred; Zipf, Peter; Smit, L.T.; Havinga, Paul J.M.; Heysters, P.M.; Renovell, Michel; Rosien, M.A.J.

    Dynamically reconfigurable systems have the potential of realising efficient systems as well as providing adaptability to changing system requirements. Such systems are suitable for future mobile multimedia systems that have limited battery resources, must handle diverse data types, and must operate

  6. Robust Throughput Boosting for Low Latency Dynamic Partial Reconfiguration

    DEFF Research Database (Denmark)

    Nannarelli, Alberto; Re, M.; Cardarilli, Gian Carlo

    2017-01-01

    Reducing the configuration time of portions of an FPGA at run time is crucial in contemporary FPGA-based accelerators. In this work, we propose a method to increase the throughput for FPGA dynamic partial reconfiguration by using standard IP blocks. The throughput is increased by over-clocking th......Reducing the configuration time of portions of an FPGA at run time is crucial in contemporary FPGA-based accelerators. In this work, we propose a method to increase the throughput for FPGA dynamic partial reconfiguration by using standard IP blocks. The throughput is increased by over...

  7. A modeling framework for deteriorating control system and predictive maintenance of actuators

    International Nuclear Information System (INIS)

    Langeron, Y.; Grall, A.; Barros, A.

    2015-01-01

    Actuators play a central role in industrial automation systems. They are costly, and therefore studying their dependability needs all attention. Usually, an actuator is inserted in a feedback control system, and its mission is to implement a control action delivered by a controller. In this paper, a monotonic actuator deterioration is considered and it is assumed that a relationship exists between the control action and the physical actuator's deterioration. A modeling framework is proposed including a non-decreasing stochastic degradation process driving the inability for an actuator to fully implement its role. The prognosis of the actuator's residual useful lifetime is derived and used to update the controller's setting. The controller reconfiguration completes the maintenance corrective and preventive actions. This new action is suggested as an alternative for maintenance strategy. - Highlights: • A degrading control system model is proposed focusing on actuator deterioration. • It is assumed a relationship between this degradation and its loss of efficiency. • The actuator RUL is quantified as a quantile of its conditional survival function. • RUL prognosis is used to reconfigure the control input law. • This new action is suggested as an alternative for maintenance strategy

  8. Adaptive fuzzy tracking control for a constrained flexible air-breathing hypersonic vehicle based on actuator compensation

    Directory of Open Access Journals (Sweden)

    Peng Fei Wang

    2016-10-01

    Full Text Available The design of an adaptive fuzzy tracking control for a flexible air-breathing hypersonic vehicle with actuator constraints is discussed. Based on functional decomposition methodology, velocity and altitude controllers are designed. Fuzzy logic systems are applied to approximate the lumped uncertainty of each subsystem of air-breathing hypersonic vehicle model. Every controllers contain only one adaptive parameter that needs to be updated online with a minimal-learning-parameter scheme. The back-stepping design is not demanded by converting the altitude subsystem into the normal output-feedback formulation, which predigests the design of a controller. The special contribution is that novel auxiliary systems are developed to compensate both the tracking errors and desired control laws, based on which the explored controller can still provide effective tracking of velocity and altitude commands when the inputs are saturated. Finally, reference trajectory tracking simulation shows the effectiveness of the proposed method in its application to air-breathing hypersonic vehicle control.

  9. Self-Sensing Control of Nafion-Based Ionic Polymer-Metal Composite (IPMC Actuator in the Extremely Low Humidity Environment

    Directory of Open Access Journals (Sweden)

    Minoru Sasaki

    2013-10-01

    Full Text Available This paper presents feedforward, feedback and two-degree-of-freedom control applied to an Ionic Polymer-Metal Composite (IPMC actuator. It presents a high potential for development of miniature robots and biomedical devices and artificial muscles. We have reported in the last few years that dehydration treatment improves the electrical controllability of bending in Selemion CMV-based IPMCs. We tried to replicate this controllability in Nafion-based IPMC. We found that the displacement of a Nafion-based IPMC was proportional to the total charge imposed, just as in the Selemion-CMV case. This property is the basis of self-sensing controllers for Nafion-based IPMC bending behavior: we perform bending curvature experiments on Nafion-based IPMCs, obtaining the actuator's dynamics and transfer function. From these, we implemented self-sensing controllers using feedforward, feedback and two-degree-of-freedom techniques. All three controllers performed very well with the Nafion-based IPMC actuator.

  10. Available Resources for Reconfigurable Systems in 5G Networks

    DEFF Research Database (Denmark)

    Rodríguez Páez, Juan Sebastián; Vegas Olmos, Juan José

    2017-01-01

    In this paper, the concept of a Radio-over-Fiber based Centralized Radio Access Network is explained and analyzed, in order to identify a set of resources within the network that can be used as a base in the design of reconfigurable systems. This analysis is then used to design a different reconf...

  11. An adaptive cryptographic accelerator for network storage security on dynamically reconfigurable platform

    Science.gov (United States)

    Tang, Li; Liu, Jing-Ning; Feng, Dan; Tong, Wei

    2008-12-01

    Existing security solutions in network storage environment perform poorly because cryptographic operations (encryption and decryption) implemented in software can dramatically reduce system performance. In this paper we propose a cryptographic hardware accelerator on dynamically reconfigurable platform for the security of high performance network storage system. We employ a dynamic reconfigurable platform based on a FPGA to implement a PowerPCbased embedded system, which executes cryptographic algorithms. To reduce the reconfiguration latency, we apply prefetch scheduling. Moreover, the processing elements could be dynamically configured to support different cryptographic algorithms according to the request received by the accelerator. In the experiment, we have implemented AES (Rijndael) and 3DES cryptographic algorithms in the reconfigurable accelerator. Our proposed reconfigurable cryptographic accelerator could dramatically increase the performance comparing with the traditional software-based network storage systems.

  12. Analysing the Hydraulic Actuator-based Knee Unit Kinematics and Correlating the Numerical Results and Walking Human Knee Joint Behavior

    Directory of Open Access Journals (Sweden)

    K. A. Trukhanov

    2014-01-01

    Full Text Available State-of-the-art machinery development enables people with lost lower limb to continue their previous life despite a loss. International companies dealing with this area pursue a minimization of human behaviour problems because of amputation. Researches to create an optimal design of the artificial knee joint are under way.The work task was to define analytical relationships of changing kinematic parameters of the human walking on the flat surface such as an angle of the knee joint, knee point (moment, definition of reduced knee actuator (A load, as well as to compare obtained results with experimental data.As an A in created design, the article proposes to use a controlled shock absorber based on the hydraulic cylinder.A knee unit is a kinematic two-tier mechanism. One of the mechanism links performs rotational motion, and the other is rotation-translational to provide a rotation of the first one.When studying the hydraulic actuator device dynamics, as a generalized coordinate a coordinate of the piston x (or ρ position is chosen while in the study of link movements an angle β is preferable.Experimental data are obtained for a human with the body weight of 57.6 kg walking on the flat surface to estimate a value of the knee joint angle, speed, acceleration, torque, and capacity in the knee joint and are taken from the published works of foreign authors.A trigonometric approximation was used for fitting the experimental data. The resulting dependence of the reduced load on the stock of A is necessary to perform the synthesis of A. The criterion for linear mechanisms mentioned in the D.N. Popov’s work is advisable to use as a possible criterion for optimization of A.The results obtained are as follows:1. Kinematics linkage mechanism is described using relationships for dependencies of its geometrical parameters, namely a cylinder piston stroke x (or ρ and a links angle β.2. Obtained polynomials of kinematic relationships allow a synthesis of

  13. Pass-band reconfigurable spoof surface plasmon polaritons

    Science.gov (United States)

    Zhang, Hao Chi; He, Pei Hang; Gao, Xinxin; Tang, Wen Xuan; Cui, Tie Jun

    2018-04-01

    In this paper, we introduce a new scheme to construct the band-pass tunable filter based on the band-pass reconfigurable spoof surface plasmon polaritons (SPPs), whose cut-off frequencies at both sides of the passband can be tuned through changing the direct current (DC) bias of varactors. Compared to traditional technology (e.g. microstrip filters), the spoof SPP structure can provide more tight field confinement and more significant field enhancement, which is extremely valuable for many system applications. In order to achieve this scheme, we proposed a specially designed SPP filter integrated with varactors and DC bias feeding structure to support the spoof SPP passband reconfiguration. Furthermore, the full-wave simulated result verifies the outstanding performance on both efficiency and reconfiguration, which has the potential to be widely used in advanced intelligent systems.

  14. A Method for Design of Modular Reconfigurable Machine Tools

    Directory of Open Access Journals (Sweden)

    Zhengyi Xu

    2017-02-01

    Full Text Available Presented in this paper is a method for the design of modular reconfigurable machine tools (MRMTs. An MRMT is capable of using a minimal number of modules through reconfiguration to perform the required machining tasks for a family of parts. The proposed method consists of three steps: module identification, module determination, and layout synthesis. In the first step, the module components are collected from a family of general-purpose machines to establish a module library. In the second step, for a given family of parts to be machined, a set of needed modules are selected from the module library to construct a desired reconfigurable machine tool. In the third step, a final machine layout is decided though evaluation by considering a number of performance indices. Based on this method, a software package has been developed that can design an MRMT for a given part family.

  15. Supporting scalable Bayesian networks using configurable discretizer actuators

    CSIR Research Space (South Africa)

    Osunmakinde, I

    2009-04-01

    Full Text Available The authors propose a generalized model with configurable discretizer actuators as a solution to the problem of the discretization of massive numerical datasets. Their solution is based on a concurrent distribution of the actuators and uses dynamic...

  16. Soft, Rotating Pneumatic Actuator.

    Science.gov (United States)

    Ainla, Alar; Verma, Mohit S; Yang, Dian; Whitesides, George M

    2017-09-01

    This article describes a soft pneumatic actuator that generates cyclical motion. The actuator consists of several (three, four, or five) chambers (arranged around the circumference of a circle surrounding a central rod) that can be actuated independently using negative pressure (or partial vacuum). Sequential actuation of the four-chamber device using reduced pressure moves the central rod cyclically in an approximately square path. We characterize the trajectory of the actuator and the force exerted by it, as we vary the material used for fabrication, the number of chambers, and the size of the actuator. We demonstrate two applications of this actuator: to deliver fluid while stirring (by replacing the central rod with a needle) and for locomotion that mimics a reptilian gait (by combining four actuators together).

  17. Hardware support for software controlled fast reconfiguration of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-06-18

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  18. Characterization of a smartphone size haptic rendering system based on thin-film AlN actuators on glass substrates

    Science.gov (United States)

    Bernard, F.; Casset, F.; Danel, J. S.; Chappaz, C.; Basrour, S.

    2016-08-01

    This paper presents for the first time the characterization of a smartphone-size haptic rendering system based on the friction modulation effect. According to previous work and finite element modeling, the homogeneous flexural modes are needed to get the haptic feedback effect. The device studied consists of a thin film AlN transducers deposited on an 110  ×  65 mm2 glass substrate. The transducer’s localization on the glass plate allows a transparent central area of 90  ×  49 mm2. Electrical and mechanical parameters of the system are extracted from measurement. From this extraction, the electrical impedance matching reduced the applied voltage to 17.5 V AC and the power consumption to 1.53 W at the resonance frequency of the vibrating system to reach the haptic rendering specification. Transient characterizations of the actuation highlight a delay under the dynamic tactile detection. The characterization of the AlN transducers used as sensors, including the noise rejection, the delay or the output charge amplitude allows detections with high accuracy of any variation due to external influences. Those specifications are the first step to a low-power-consumption feedback-looped system.

  19. Characterization of a smartphone size haptic rendering system based on thin-film AlN actuators on glass substrates

    International Nuclear Information System (INIS)

    Bernard, F; Basrour, S; Casset, F; Danel, J S; Chappaz, C

    2016-01-01

    This paper presents for the first time the characterization of a smartphone-size haptic rendering system based on the friction modulation effect. According to previous work and finite element modeling, the homogeneous flexural modes are needed to get the haptic feedback effect. The device studied consists of a thin film AlN transducers deposited on an 110  ×  65 mm 2 glass substrate. The transducer’s localization on the glass plate allows a transparent central area of 90  ×  49 mm 2 . Electrical and mechanical parameters of the system are extracted from measurement. From this extraction, the electrical impedance matching reduced the applied voltage to 17.5 V AC and the power consumption to 1.53 W at the resonance frequency of the vibrating system to reach the haptic rendering specification. Transient characterizations of the actuation highlight a delay under the dynamic tactile detection. The characterization of the AlN transducers used as sensors, including the noise rejection, the delay or the output charge amplitude allows detections with high accuracy of any variation due to external influences. Those specifications are the first step to a low-power-consumption feedback-looped system. (paper)

  20. Chaos Suppression of an Electrically Actuated Microresonator Based on Fractional-Order Nonsingular Fast Terminal Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Jianxin Han

    2017-01-01

    Full Text Available This paper focuses on chaos suppression strategy of a microresonator actuated by two symmetrical electrodes. Dynamic behavior of this system under the case where the origin is the only stable equilibrium is investigated first. Numerical simulations reveal that system may exhibit chaotic motion under certain excitation conditions. Then, bifurcation diagrams versus amplitude or frequency of AC excitation are drawn to grasp system dynamics nearby its natural frequency. Results show that the vibration is complex and may exhibit period-doubling bifurcation, chaotic motion, or dynamic pull-in instability. For the suppression of chaos, a novel control algorithm, based on an integer-order nonsingular fast terminal sliding mode and a fractional-order switching law, is proposed. Fractional Lyapunov Stability Theorem is used to guarantee the asymptotic stability of the system. Finally, numerical results with both fractional-order and integer-order control laws show that our proposed control law is effective in controlling chaos with system uncertainties and external disturbances.

  1. Modular, Reconfigurable, High-Energy Technology Development

    Science.gov (United States)

    Carrington, Connie; Howell, Joe

    2006-01-01

    The Modular, Reconfigurable High-Energy (MRHE) Technology Demonstrator project was to have been a series of ground-based demonstrations to mature critical technologies needed for in-space assembly of a highpower high-voltage modular spacecraft in low Earth orbit, enabling the development of future modular solar-powered exploration cargo-transport vehicles and infrastructure. MRHE was a project in the High Energy Space Systems (HESS) Program, within NASA's Exploration Systems Research and Technology (ESR&T) Program. NASA participants included Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), and Glenn Research Center (GRC). Contractor participants were the Boeing Phantom Works in Huntsville, AL, Lockheed Martin Advanced Technology Center in Palo Alto, CA, ENTECH, Inc. in Keller, TX, and the University of AL Huntsville (UAH). MRHE's technical objectives were to mature: (a) lightweight, efficient, high-voltage, radiation-resistant solar power generation (SPG) technologies; (b) innovative, lightweight, efficient thermal management systems; (c) efficient, 100kW-class, high-voltage power delivery systems from an SPG to an electric thruster system; (d) autonomous rendezvous and docking technology for in-space assembly of modular, reconfigurable spacecraft; (e) robotic assembly of modular space systems; and (f) modular, reconfigurable distributed avionics technologies. Maturation of these technologies was to be implemented through a series of increasingly-inclusive laboratory demonstrations that would have integrated and demonstrated two systems-of-systems: (a) the autonomous rendezvous and docking of modular spacecraft with deployable structures, robotic assembly, reconfiguration both during assembly and (b) the development and integration of an advanced thermal heat pipe and a high-voltage power delivery system with a representative lightweight high-voltage SPG array. In addition, an integrated simulation testbed would have been developed

  2. Plasma actuators for bluff body flow control

    Science.gov (United States)

    Kozlov, Alexey V.

    noise. A tandem cylinder configuration with the plasma actuation on the upstream cylinder is investigated using surface dynamic pressure sensors. As a result of the plasma actuation, the surface pressure fluctuations on the downstream cylinder are reduced by about two times at the free-stream velocity of 40 m/s (ReD = 164,000). In addition, this study presents the results of a parametric experimental investigation aimed at optimizing the body force produced by single dielectric barrier discharge (SDBD) plasma actuators used for aerodynamic flow control. A primary goal of the study is the improvement of actuator authority for flow control applications at higher Reynolds number than previously possible. The study examines the effects of dielectric material and thickness, applied voltage amplitude and frequency, voltage waveform, exposed electrode geometry, covered electrode width and multiple actuator arrays. The metric used to evaluate the performance of the actuator in each case is the measured actuator-induced thrust which is proportional to the total body force. It is demonstrated that actuators constructed with thick dielectric material of low dielectric constant and operated at low frequency AC voltage produce a body force that is an order of magnitude larger than that obtained by the Kapton-based actuators used in many previous plasma flow control studies. These actuators allow operation at much higher applied voltages without the formation of discrete streamers which lead to body force saturation.

  3. Extended DNA Tile Actuators

    DEFF Research Database (Denmark)

    Kristiansen, Martin; Kryger, Mille; Zhang, Zhao

    2012-01-01

    A dynamic linear DNA tile actuator is expanded to three new structures of higher complexity. The original DNA actuator was constructed from a central roller strand which hybridizes with two piston strands by forming two half-crossover junctions. A linear expansion of the actuator is obtained...

  4. Design and fabrication of PMMA-micromachined fluid lens based on electromagnetic actuation on PMMA–PDMS bonded membrane

    International Nuclear Information System (INIS)

    Lee, June Kyoo; Park, Kyung-Woo; Choi, Ju Chan; Kim, Hak-Rin; Kong, Seong Ho

    2012-01-01

    The fabrication of a poly(methyl methacrylate) (PMMA)-micromachined fluid lens with an optimally designed built-in electromagnetic actuator was demonstrated in this study. Through a finite element method, the number of winding turns and the distance between magnetic moments were estimated to design an effective and miniaturized electromagnetic actuator. The lens body composed of PMMA structures was simply and rapidly micromachined using computer numerical control micro-milling. The poly(dimethylsiloxane) (PDMS) membranes for electromagnetic actuation were bonded to the PMMA structures by using the proposed PMMA–PDMS bonding technique, which uses an SiO 2 intermediate layer. A physical repulsive force produced by the electromagnetic actuator applies a controllable fluidic pressure to a fluidic chamber that is sealed with the PDMS membrane, thus allowing dynamic focusing. The focus tunability of the fabricated lens was 67 diopters with a focus hysteresis of less than 1 mm and a response time of 2 ms. The solenoid of the built-in actuator showed negligible thermal crosstalk to the lens. (paper)

  5. Single-crystal-material-based induced-shear actuation for vibration reduction of helicopters with composite rotor system

    International Nuclear Information System (INIS)

    Pawar, Prashant M; Jung, Sung Nam

    2008-01-01

    In this study, an assessment is made for the helicopter vibration reduction of composite rotor blades using an active twist control concept. Special focus is given to the feasibility of implementing the benefits of the shear actuation mechanism along with elastic couplings of composite blades for achieving maximum vibration reduction. The governing equations of motion for composite rotor blades with surface bonded piezoceramic actuators are obtained using Hamilton's principle. The equations are then solved for dynamic response using finite element discretization in the spatial and time domains. A time domain unsteady aerodynamic theory with free wake model is used to obtain the airloads. A newly developed single-crystal piezoceramic material is introduced as an actuator material to exploit its superior shear actuation authority. Seven rotor blades with different elastic couplings representing stiffness properties similar to stiff-in-plane rotor blades are used to investigate the hub vibration characteristics. The rotor blades are modeled as a box beam with actuator layers bonded on the outer surface of the top and bottom of the box section. Numerical results show that a notable vibration reduction can be achieved for all the combinations of composite rotor blades. This investigation also brings out the effect of different elastic couplings on various vibration-reduction-related parameters which could be useful for the optimal design of composite helicopter blades

  6. Single-crystal-material-based induced-shear actuation for vibration reduction of helicopters with composite rotor system

    Science.gov (United States)

    Pawar, Prashant M.; Jung, Sung Nam

    2008-12-01

    In this study, an assessment is made for the helicopter vibration reduction of composite rotor blades using an active twist control concept. Special focus is given to the feasibility of implementing the benefits of the shear actuation mechanism along with elastic couplings of composite blades for achieving maximum vibration reduction. The governing equations of motion for composite rotor blades with surface bonded piezoceramic actuators are obtained using Hamilton's principle. The equations are then solved for dynamic response using finite element discretization in the spatial and time domains. A time domain unsteady aerodynamic theory with free wake model is used to obtain the airloads. A newly developed single-crystal piezoceramic material is introduced as an actuator material to exploit its superior shear actuation authority. Seven rotor blades with different elastic couplings representing stiffness properties similar to stiff-in-plane rotor blades are used to investigate the hub vibration characteristics. The rotor blades are modeled as a box beam with actuator layers bonded on the outer surface of the top and bottom of the box section. Numerical results show that a notable vibration reduction can be achieved for all the combinations of composite rotor blades. This investigation also brings out the effect of different elastic couplings on various vibration-reduction-related parameters which could be useful for the optimal design of composite helicopter blades.

  7. Nested Reconfigurable Robots: Theory, Design, and Realization

    Directory of Open Access Journals (Sweden)

    Ning Tan

    2015-07-01

    Full Text Available Rather than the conventional classification method, we propose to divide modular and reconfigurable robots into intra-, inter-, and nested reconfigurations. We suggest designing the robot with nested reconfigurability, which utilizes individual robots with intra-reconfigurability capable of combining with other homogeneous/heterogeneous robots (inter-reconfigurability. The objective of this approach is to generate more complex morphologies for performing specific tasks that are far from the capabilities of a single module or to respond to programmable assembly requirements. In this paper, we discuss the theory, concept, and initial mechanical design of Hinged-Tetro, a self-reconfigurable module conceived for the study of nested reconfiguration. Hinged-Tetro is a mobile robot that uses the principle of hinged dissection of polyominoes to transform itself into any of the seven one-sided tetrominoes in a straightforward way. The robot can also combine with other modules for shaping complex structures or giving rise to a robot with new capabilities. Finally, the validation experiments verify the nested reconfigurability of Hinged-Tetro. Extensive tests and analyses of intra-reconfiguration are provided in terms of energy and time consumptions. Experiments using two robots validate the inter-reconfigur ability of the proposed module.

  8. Red-light-controllable liquid-crystal soft actuators via low-power excited upconversion based on triplet-triplet annihilation.

    Science.gov (United States)

    Jiang, Zhen; Xu, Ming; Li, Fuyou; Yu, Yanlei

    2013-11-06

    A red-light-controllable soft actuator has been achieved, driven by low-power excited triplet-triplet annihilation-based upconversion luminescence (TTA-UCL). First, a red-to-blue TTA-based upconversion system with a high absolute quantum yield of 9.3 ± 0.5% was prepared by utilizing platinum(II) tetraphenyltetrabenzoporphyrin (PtTPBP) as the sensitizer and 9,10-bis(diphenylphosphoryl)anthracene (BDPPA) as the annihilator. In order to be employed as a highly effective phototrigger of photodeformable cross-linked liquid-crystal polymers (CLCPs), the PtTPBP&BDPPA system was incorporated into a rubbery polyurethane film and then assembled with an azotolane-containing CLCP film. The generating assembly film bent toward the light source when irradiated with a 635 nm laser at low power density of 200 mW cm(-2) because the TTA-UCL was effectively utilized by the azotolane moieties in the CLCP film, inducing their trans-cis photoisomerization and an alignment change of the mesogens via an emission-reabsorption process. It is the first example of a soft actuator in which the TTA-UCL is trapped and utilized to create photomechanical effect. Such advantages of using this novel red-light-controllable soft actuator in potential biological applications have also been demonstrated as negligible thermal effect and its excellent penetration ability into tissues. This work not only provides a novel photomanipulated soft actuation material system based on the TTA-UCL technology but also introduces a new technological application of the TTA-based upconversion system in photonic devices.

  9. Schematic Approach to Information Services Reconfiguration

    Directory of Open Access Journals (Sweden)

    Sabah Al-Fedaghi

    2015-02-01

    Full Text Available Information system change is concerned with deliberate modifications to an organization’s technical and organiza‐ tional subsystems that deal with information. Changes result in adjustments being made to the configuration of information systems that could have an impact on the operations of those systems. This paper examines the problem of interference between old configuration activi‐ ties, new configuration activities and reconfiguration activities that occur due to overlapping modes. The paper proposes a novel form of depicting and solving the problem based on a flow-based conceptualization in which a configuration can be viewed as a system of flow systems organized architecturally, described by their internal flows, and connected by external flows and triggering. This method of diagramming is applied to a complex case study involving the reconfiguration of an office workflow for order processing described in BPMN. The diagrams resulting from this method and the BPMN diagrams are then examined side by side. Accordingly, the conclusion is that a new high-level representation seems more system‐ atic as a foundation for building a conceptual schema of business processes.

  10. Quasi-static analysis and control of planer and spatial bending fluidic actuator

    OpenAIRE

    Chang, Benjamin Che-Ming

    2011-01-01

    This work presents a novel silicone-based millimetre scale bending fluidic actuator. Two designs of the bending fluidic actuator are studied: a planer actuator that bends about one axis; and a spatial actuator able to bend about two orthogonal axes. The unique parallel micro-channel design of the fluidic actuators enables operation at low working pressures, while at the same time having a very limited thickness expansion during pressurization. The fluidic actuators can be easily scaled to des...

  11. Reconfigurable engineered motile semiconductor microparticles.

    Science.gov (United States)

    Ohiri, Ugonna; Shields, C Wyatt; Han, Koohee; Tyler, Talmage; Velev, Orlin D; Jokerst, Nan

    2018-05-03

    Locally energized particles form the basis for emerging classes of active matter. The design of active particles has led to their controlled locomotion and assembly. The next generation of particles should demonstrate robust control over their active assembly, disassembly, and reconfiguration. Here we introduce a class of semiconductor microparticles that can be comprehensively designed (in size, shape, electric polarizability, and patterned coatings) using standard microfabrication tools. These custom silicon particles draw energy from external electric fields to actively propel, while interacting hydrodynamically, and sequentially assemble and disassemble on demand. We show that a number of electrokinetic effects, such as dielectrophoresis, induced charge electrophoresis, and diode propulsion, can selectively power the microparticle motions and interactions. The ability to achieve on-demand locomotion, tractable fluid flows, synchronized motility, and reversible assembly using engineered silicon microparticles may enable advanced applications that include remotely powered microsensors, artificial muscles, reconfigurable neural networks and computational systems.

  12. Design of reconfigurable logic controllers

    CERN Document Server

    Bukowiec, Arkadiusz; Doligalski, Michał; Tkacz, Jacek

    2016-01-01

    This book presents the original concepts and modern techniques for specification, synthesis, optimisation and implementation of parallel logical control devices. It deals with essential problems of reconfigurable control systems like dependability, modularity and portability. Reconfigurable systems require a wider variety of design and verification options than the application-specific integrated circuits. The book presents a comprehensive selection of possible design techniques. The diversity of the modelling approaches covers Petri nets, state machines and activity diagrams. The preferences of the presented optimization and synthesis methods are not limited to increasing of the efficiency of resource use. One of the biggest advantages of the presented methods is the platform independence, the FPGA devices and single board computers are some of the examples of possible platforms. These issues and problems are illustrated with practical cases of complete control systems. If you expect a new look at the recon...

  13. An Embedded Reconfigurable Logic Module

    Science.gov (United States)

    Tucker, Jerry H.; Klenke, Robert H.; Shams, Qamar A. (Technical Monitor)

    2002-01-01

    A Miniature Embedded Reconfigurable Computer and Logic (MERCAL) module has been developed and verified. MERCAL was designed to be a general-purpose, universal module that that can provide significant hardware and software resources to meet the requirements of many of today's complex embedded applications. This is accomplished in the MERCAL module by combining a sub credit card size PC in a DIMM form factor with a XILINX Spartan I1 FPGA. The PC has the ability to download program files to the FPGA to configure it for different hardware functions and to transfer data to and from the FPGA via the PC's ISA bus during run time. The MERCAL module combines, in a compact package, the computational power of a 133 MHz PC with up to 150,000 gate equivalents of digital logic that can be reconfigured by software. The general architecture and functionality of the MERCAL hardware and system software are described.

  14. Reconfigurable Model Execution in the OpenMDAO Framework

    Science.gov (United States)

    Hwang, John T.

    2017-01-01

    NASA's OpenMDAO framework facilitates constructing complex models and computing their derivatives for multidisciplinary design optimization. Decomposing a model into components that follow a prescribed interface enables OpenMDAO to assemble multidisciplinary derivatives from the component derivatives using what amounts to the adjoint method, direct method, chain rule, global sensitivity equations, or any combination thereof, using the MAUD architecture. OpenMDAO also handles the distribution of processors among the disciplines by hierarchically grouping the components, and it automates the data transfer between components that are on different processors. These features have made OpenMDAO useful for applications in aircraft design, satellite design, wind turbine design, and aircraft engine design, among others. This paper presents new algorithms for OpenMDAO that enable reconfigurable model execution. This concept refers to dynamically changing, during execution, one or more of: the variable sizes, solution algorithm, parallel load balancing, or set of variables-i.e., adding and removing components, perhaps to switch to a higher-fidelity sub-model. Any component can reconfigure at any point, even when running in parallel with other components, and the reconfiguration algorithm presented here performs the synchronized updates to all other components that are affected. A reconfigurable software framework for multidisciplinary design optimization enables new adaptive solvers, adaptive parallelization, and new applications such as gradient-based optimization with overset flow solvers and adaptive mesh refinement. Benchmarking results demonstrate the time savings for reconfiguration compared to setting up the model again from scratch, which can be significant in large-scale problems. Additionally, the new reconfigurability feature is applied to a mission profile optimization problem for commercial aircraft where both the parametrization of the mission profile and the

  15. Neural network-based robust actuator fault diagnosis for a non-linear multi-tank system.

    Science.gov (United States)

    Mrugalski, Marcin; Luzar, Marcel; Pazera, Marcin; Witczak, Marcin; Aubrun, Christophe

    2016-03-01

    The paper is devoted to the problem of the robust actuator fault diagnosis of the dynamic non-linear systems. In the proposed method, it is assumed that the diagnosed system can be modelled by the recurrent neural network, which can be transformed into the linear parameter varying form. Such a system description allows developing the designing scheme of the robust unknown input observer within H∞ framework for a class of non-linear systems. The proposed approach is designed in such a way that a prescribed disturbance attenuation level is achieved with respect to the actuator fault estimation error, while guaranteeing the convergence of the observer. The application of the robust unknown input observer enables actuator fault estimation, which allows applying the developed approach to the fault tolerant control tasks. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  16. SaRDIn - A Safe Reconfigurable Distributed Interlocking

    DEFF Research Database (Denmark)

    Fantechi, Alessandro; Gnesi, S.; Haxthausen, Anne Elisabeth

    2016-01-01

    Current computer-based interlocking systems most often have a centralized design, with all logic residing in a single computer. Centralized interlockings are complex to design. Following the general trend in Cyber-Physical Systems, the SaRDIn (Safe Reconfigurable Distributed Interlockings) concept...

  17. Reconfigurable digital receiver design and application for instantaneous polarimetric measurement

    NARCIS (Netherlands)

    Wang, Z.; Krasnov, O.A.; Babur, G.P.; Ligthart, L.P.; Van der Zwan, F.

    2011-01-01

    This paper presents the development of a reconfigurable receiver to undertake challenging signal processing tasks for a novel polarimetric radar system. The field-programmable gate arrays (FPGAs)-based digital receiver samples incoming signals at intermediate frequency (IF) and processes signals

  18. Hardware/software virtualization for the reconfigurable multicore platform.

    NARCIS (Netherlands)

    Ferger, M.; Al Kadi, M.; Hübner, M.; Koedam, M.L.P.J.; Sinha, S.S.; Goossens, K.G.W.; Marchesan Almeida, Gabriel; Rodrigo Azambuja, J.; Becker, Juergen

    2012-01-01

    This paper presents the Flex Tiles approach for the virtualization of hardware and software for a reconfigurable multicore architecture. The approach enables the virtualization of a dynamic tile-based hardware architecture consisting of processing tiles connected via a network-on-chip and a

  19. Split and flow: reconfigurable capillary connection for digital microfluidic devices.

    Science.gov (United States)

    Lapierre, Florian; Harnois, Maxime; Coffinier, Yannick; Boukherroub, Rabah; Thomy, Vincent

    2014-09-21

    Supplying liquid to droplet-based microfluidic microsystems remains a delicate task facing the problems of coupling continuous to digital or macro- to microfluidic systems. Here, we take advantage of superhydrophobic microgrids to address this problem. Insertion of a capillary tube inside a microgrid aperture leads to a simple and reconfigurable droplet generation setup.

  20. Intelligent Hydraulic Actuator and Exp-based Modelling of Losses in Pumps and .

    DEFF Research Database (Denmark)

    Zhang, Muzhi

    A intelligent fuzzy logic self-organising PD+I controller for a gearrotor hydraulic motor was developed and evaluated. Furthermore, a experimental-based modelling methods with a new software tool 'Dynamodata' for modelling of losses in hydraulic motors and pumps was developed.......A intelligent fuzzy logic self-organising PD+I controller for a gearrotor hydraulic motor was developed and evaluated. Furthermore, a experimental-based modelling methods with a new software tool 'Dynamodata' for modelling of losses in hydraulic motors and pumps was developed....