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....

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.

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.

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

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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...

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.

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...

10–25 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)

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

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

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

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...

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.

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)

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

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).

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)

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.

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.

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.

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...

Magnetic Actuation of Self-Assembled DNA Hinges

Science.gov (United States)

Lauback, S.; Mattioli, K.; Armstrong, M.; Miller, C.; Pease, C.; Castro, C.; Sooryakumar, R.

DNA nanotechnology offers a broad range of applications spanning from the creation of nanoscale devices, motors and nanoparticle templates to the development of precise drug delivery systems. Central to advancing this technology is the ability to actuate or reconfigure structures in real time, which is currently achieved primarily by DNA strand displacement yielding slow actuation times (about 1-10min). Here we exploit superparamagnetic beads to magnetically actuate DNA structures which also provides a system to measure forces associated with molecular interactions. DNA nanodevices are folded using DNA origami, whereby a long single-stranded DNA is folded into a precise compact geometry using hundreds of short oligonucleotides. Our DNA nanodevice is a nanohinge from which rod shaped DNA nanostructures are polymerized into micron-scale filaments forming handles for actuation. By functionalizing one arm of the hinge and the filament ends, the hinge can be attached to a surface while still allowing an arm to rotate and the filaments can be labeled with magnetic beads enabling the hinge to be actuated almost instantaneously by external magnetic fields. These results lay the groundwork to establish real-time manipulation and direct force application of DNA constructs.

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

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.

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.

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.

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

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

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.

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

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

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

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)

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.

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.

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.

Control of soft machines using actuators operated by a Braille display.

Science.gov (United States)

Mosadegh, Bobak; Mazzeo, Aaron D; Shepherd, Robert F; Morin, Stephen A; Gupta, Unmukt; Sani, Idin Zhalehdoust; Lai, David; Takayama, Shuichi; Whitesides, George M

2014-01-07

One strategy for actuating soft machines (e.g., tentacles, grippers, and simple walkers) uses pneumatic inflation of networks of small channels in an elastomeric material. Although the management of a few pneumatic inputs and valves to control pressurized gas is straightforward, the fabrication and operation of manifolds containing many (>50) independent valves is an unsolved problem. Complex pneumatic manifolds-often built for a single purpose-are not easily reconfigured to accommodate the specific inputs (i.e., multiplexing of many fluids, ranges of pressures, and changes in flow rates) required by pneumatic systems. This paper describes a pneumatic manifold comprising a computer-controlled Braille display and a micropneumatic device. The Braille display provides a compact array of 64 piezoelectric actuators that actively close and open elastomeric valves of a micropneumatic device to route pressurized gas within the manifold. The positioning and geometries of the valves and channels in the micropneumatic device dictate the functionality of the pneumatic manifold, and the use of multi-layer soft lithography permits the fabrication of networks in a wide range of configurations with many possible functions. Simply exchanging micropneumatic devices of different designs enables rapid reconfiguration of the pneumatic manifold. As a proof of principle, a pneumatic manifold controlled a soft machine containing 32 independent actuators to move a ball above a flat surface.

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.

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...

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.

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.

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...

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.

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.

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.

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.

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.

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.

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.

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

Reconfigurable origami sonic barriers with tunable bandgaps for traffic noise mitigation

Science.gov (United States)

Thota, M.; Wang, K. W.

2017-10-01

An origami sonic barrier composed of cylindrical inclusions attached onto an origami sheet is proposed. The idea allows for tunable sound blocking properties for application in attenuating complex traffic noise spectra. Folding of the underlying origami sheet transforms the periodicity of the inclusions between different Bravais lattices, viz. between a square and a hexagonal lattice, and such significant lattice re-configuration leads to drastic tuning of dispersion characteristics. The wave tuning capabilities are corroborated via performing theoretical and numerical investigations using a plane wave expansion method and an acoustic simulation package of COMSOL, while experiments are performed on a one-seventh scaled-down model of origami sonic barrier to demonstrate the lattice re-configuration between different Bravais lattices and the associated bandgap adaptability. Good sound blocking performance in the frequency range of traffic noise spectra combined with less efforts, required for actuating one-degree of freedom folding mechanism, makes the origami sonic barrier a potential candidate for mitigating complex traffic noise.

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

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.

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.

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

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...

Soft-rigid interaction mechanism towards a lobster-inspired hybrid actuator

Science.gov (United States)

Chen, Yaohui; Wan, Fang; Wu, Tong; Song, Chaoyang

2018-01-01

Soft pneumatic actuators (SPAs) are intrinsically light-weight, compliant and therefore ideal to directly interact with humans and be implemented into wearable robotic devices. However, they also pose new challenges in describing and sensing their continuous deformation. In this paper, we propose a hybrid actuator design with bio-inspirations from the lobsters, which can generate reconfigurable bending movements through the internal soft chamber interacting with the external rigid shells. This design with joint and link structures enables us to exactly track its bending configurations that previously posed a significant challenge to soft robots. Analytic models are developed to illustrate the soft-rigid interaction mechanism with experimental validation. A robotic glove using hybrid actuators to assist grasping is assembled to illustrate their potentials in safe human-robot interactions. Considering all the design merits, our work presents a practical approach to the design of next-generation robots capable of achieving both good accuracy and compliance.

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

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

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....

Fault-tolerant Control of Discrete-time LPV systems using Virtual Actuators and Sensors

DEFF Research Database (Denmark)

Tabatabaeipour, Mojtaba; Stoustrup, Jakob; Bak, Thomas

2015-01-01

This paper proposes a new fault-tolerant control (FTC) method for discrete-time linear parameter varying (LPV) systems using a reconfiguration block. The basic idea of the method is to achieve the FTC goal without re-designing the nominal controller by inserting a reconfiguration block between......, it transforms the output of the controller for the faulty system such that the stability and performance goals are preserved. Input-to-state stabilizing LPV gains of the virtual actuator and sensor are obtained by solving linear matrix inequalities (LMIs). We show that separate design of these gains guarantees....... Finally, the effectiveness of the method is demonstrated via a numerical example and stator current control of an induction motor....

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.

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...

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.

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.

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.

Grasp planning for a reconfigurable parallel robot with an underactuated arm structure

Directory of Open Access Journals (Sweden)

M. Riedel

2010-12-01

Full Text Available In this paper, a novel approach of grasp planning is applied to find out the appropriate grasp points for a reconfigurable parallel robot called PARAGRIP (Parallel Gripping. This new handling system is able to manipulate objects in the six-dimensional Cartesian space by several robotic arms using only six actuated joints. After grasping, the contact elements at the end of the underactuated arm mechanisms are connected to the object which forms a closed loop mechanism similar to the architecture of parallel manipulators. As the mounting and grasp points of the arms can easily be changed, the manipulator can be reconfigured to match the user's preferences and needs. This paper raises the question, how and where these grasp points are to be placed on the object to perform well for a certain manipulation task.

This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

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...

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...

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.

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.)

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

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)

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.

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.

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

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

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.

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

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

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...

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

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.

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.

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.

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.

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.

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.

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

A grayscale pneumatic micro-valve for use in a reconfigurable tactile tablet for vision-impaired individuals

International Nuclear Information System (INIS)

Schneider, Joseph Devin; Rebolledo-Mendez, Jovan David; McNamara, Shamus

2015-01-01

The design, fabrication, and characterization of a strained bilayer film for use in a micro-valve for a reconfigurable tactile tablet for vision-impaired individuals is presented. The bilayer film consists of a compressive and tensile layer to cause the film to coil and retract from the gas channel when the micro-valve is in the open position. A novel support structure that improves yield and controls the direction of coiling is demonstrated. An array of 225 strained bilayer films was designed and fabricated. Each strained bilayer film was able to be actuated individually with a voltage that ranged between 60 and 70 V. The relationship between the applied voltage and the percentage open of the micro-valve is found to be linear over an extended voltage range, enabling the reconfigurable tactile tablet to produce the equivalent of a grayscale image. (paper)

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...

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...

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...

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)

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.

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.

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...

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...

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

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.

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.

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...

Impact of reconfiguration period and photovoltaic penetration on distribution grid reconfiguration

DEFF Research Database (Denmark)

Chittur Ramaswamy, Parvathy; Deconinck, Geert; Pillai, Jayakrishnan Radhakrishna

2014-01-01

of reconfiguration and its impact on network losses in the context of time-varying load. Though reconfiguring a network reduces the losses, this paper calls for a comparison of number of switching vs. the loss reduction in order to decide the period of reconfiguration. This paper considers also the impact of varying...... photovoltaic (PV) penetration on the resulting optimal configuration. It validates the method of using a parameter namely minimum loss reduction parameter to avoid tedious computational efforts in finding the optimal configuration when an infinitesimal change in PV penetration occurs....

Roles and Self-Reconfigurable Robots

DEFF Research Database (Denmark)

Dvinge, Nicolai; Schultz, Ulrik Pagh; Christensen, David Johan

2007-01-01

A self-reconfigurable robot is a robotic device that can change its own shape. Self-reconfigurable robots are commonly built from multiple identical modules that can manipulate each other to change the shape of the robot. The robot can also perform tasks such as locomotion without changing shape......., significantly simplifying the task of programming self-reconfigurable robots. Our language fully supports programming the ATRON self-reconfigurable robot, and has been used to implement several controllers running both on the physical modules and in simulation.......A self-reconfigurable robot is a robotic device that can change its own shape. Self-reconfigurable robots are commonly built from multiple identical modules that can manipulate each other to change the shape of the robot. The robot can also perform tasks such as locomotion without changing shape....... Programming a modular, self-reconfigurable robot is however a complicated task: the robot is essentially a real-time, distributed embedded system, where control and communication paths often are tightly coupled to the current physical configuration of the robot. To facilitate the task of programming modular...

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.

Classification of Reconfiguration Resources and Lead Time for Reconfigurable Manufacturing Systems

NARCIS (Netherlands)

Ing. Erik Puik; Daniël Telgen; Leo van Moergestel; Darek Ceglarek

2014-01-01

From the article: Manufacturing technology can improve the turnover of a company if it enables fast market introduction for volume production. Reconfigurable equipment is developed to meet the growing demand for more agile production. Modular reconfiguration, defined as changing the structure of

External Environment Sensing by a Module on Self-reconfiguration Robot

Science.gov (United States)

Goto, Tomotsugu; Uchida, Masafumi; Onogaki, Hitoshi

In the situation in which a robot and a human work together by collaborating with each other, a robot and a human share one working environment, and each interferes in each other. The boundary of each complex dynamic occupation area changes in the connection movement which is the component of collaborative works at this time. The main restraint condition which relates to the robustness of that connection movement is each physical charactristics, that is, the embodiment. A robot body is variability though the embodiment of a human is almost fixed. Therefore, the safe and the robust connection movement is brought when a robot has the robot body which is well suitable for the embodiment of a human. A purpose for this research is that the colaboration works between the self-reconfiguration robot and a human is realized. To achieve this purpose, sensing function of external environment on a module was examined. A module is a component of the self-reconfiguration robot. A robot body vibrates when a module actuates an arm actively. This vibration is observed by using some acceleration sensors. Measured datas reflects a difference of objects that it touches a robot body. In this paper, the sensing technique of external environment which identifies this difference by using the neural network is proposed.

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.

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.

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)

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.

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.

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.

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.

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.

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 ...

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.

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

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

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.

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.

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

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.

A Modular, Reconfigurable Mold for a Soft Robotic Gripper Design Activity

Directory of Open Access Journals (Sweden)

Jiawei Zhang

2017-09-01

Full Text Available Soft robotics is an emerging field with strong potential to serve as an educational tool due to its advantages such as low costs and shallow learning curves. In this paper, we introduce a modular and reconfigurable mold for flexible design of pneumatic soft robotic grippers. By using simple assembly kits, students at all levels are able to design and construct soft robotic grippers that vary in function and performance. The process of constructing the modular mold enables students to understand how design choices impact system performance. Our unique modular mold allows students to select the number and length of fingers in a gripper, as well as to adjust the internal geometry of the pneumatic actuator cavity, which dictates how and where bending of a finger occurs. In addition, the mold may be deconstructed and reconfigured, which allows for fast iterative design and lowers material costs (since a new mold does not need to be made to implement a design change. We further demonstrate the feasibility of the modular mold by implementing it in a soft robot design activity in classrooms and showing a sufficiently high rate of student success in designing and constructing a functional soft robotic gripper.

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

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.

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.

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

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

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 ...

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

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....

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.

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.

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.

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...

Reconfigurable vision system for real-time applications

Science.gov (United States)

Torres-Huitzil, Cesar; Arias-Estrada, Miguel

2002-03-01

Recently, a growing community of researchers has used reconfigurable systems to solve computationally intensive problems. Reconfigurability provides optimized processors for systems on chip designs, and makes easy to import technology to a new system through reusable modules. The main objective of this work is the investigation of a reconfigurable computer system targeted for computer vision and real-time applications. The system is intended to circumvent the inherent computational load of most window-based computer vision algorithms. It aims to build a system for such tasks by providing an FPGA-based hardware architecture for task specific vision applications with enough processing power, using the minimum amount of hardware resources as possible, and a mechanism for building systems using this architecture. Regarding the software part of the system, a library of pre-designed and general-purpose modules that implement common window-based computer vision operations is being investigated. A common generic interface is established for these modules in order to define hardware/software components. These components can be interconnected to develop more complex applications, providing an efficient mechanism for transferring image and result data among modules. Some preliminary results are presented and discussed.

A Framework for Hardware-Accelerated Services Using Partially Reconfigurable SoCs

Directory of Open Access Journals (Sweden)

MACHIDON, O. M.

2016-05-01

Full Text Available The current trend towards ?Everything as a Service? fosters a new approach on reconfigurable hardware resources. This innovative, service-oriented approach has the potential of bringing a series of benefits for both reconfigurable and distributed computing fields by favoring a hardware-based acceleration of web services and increasing service performance. This paper proposes a framework for accelerating web services by offloading the compute-intensive tasks to reconfigurable System-on-Chip (SoC devices, as integrated IP (Intellectual Property cores. The framework provides a scalable, dynamic management of the tasks and hardware processing cores, based on dynamic partial reconfiguration of the SoC. We have enhanced security of the entire system by making use of the built-in detection features of the hardware device and also by implementing active counter-measures that protect the sensitive data.

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

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.

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.

Efficient integration of plug-in electric vehicles via reconfigurable microgrids

International Nuclear Information System (INIS)

Kavousi-Fard, Abdollah; Khodaei, Amin

2016-01-01

This paper investigates the viability of the reconfigurable microgrids (RMGs) in facilitating the integration of plug-in electric vehicles (PEVs). The reconfiguration ability of microgrids, which is enabled by the use of remotely controlled switches (RCSs), will support the high penetration of PEVs and renewable distributed generators (DGs) while reducing the total operation cost and potentially enhance microgrid reliability. The objective of the proposed optimal scheduling problem is to minimize the total cost of power supply by distributed energy resources (DERs) and upstream network energy exchange, battery degradation cost in PEVs, cost of switching during the reconfiguration, and expected customer interruption costs as a reliability index. To address the high level of the uncertainties in the problem, a scenario-based stochastic framework is devised to capture the uncertainties associated with the charging and discharging values of PEVs, number of PEVs in each fleet, time of the daily trips for PEVs, hourly load consumption, hourly output power of renewable DGs, and hourly market price. The satisfying performance and merits of the proposed model are examined on a test microgrid. - Highlights: • Introduction of reconfigurable microgrids for providing flexible structure to manage electric loads. • Assessing the effects of the reconfiguration on the integration of PEVs. • Introduction of a stochastic framework for reducing operation and reliability costs in microgrids. • Introduction of a smart charge/discharge scheme for PEVs based on V2G during the reconfiguration.

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.

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.

Supervisory Fault Tolerant Control of the GTM UAV Using LPV Methods

Directory of Open Access Journals (Sweden)

Péni Tamás

2015-03-01

Full Text Available A multi-level reconfiguration framework is proposed for fault tolerant control of over-actuated aerial vehicles, where the levels indicate how much authority is given to the reconfiguration task. On the lowest, first level the fault is accommodated by modifying only the actuator/sensor configuration, so the fault remains hidden from the baseline controller. A dynamic reallocation scheme is applied on this level. The allocation mechanism exploits the actuator/sensor redundancy available on the aircraft. When the fault cannot be managed at the actuator/sensor level, the reconfiguration process has access to the baseline controller. Based on the LPV control framework, this is done by introducing fault-specific scheduling parameters. The baseline controller is designed to provide an acceptable performance level along all fault scenarios coded in these scheduling variables. The decision on which reconfiguration level has to be initiated in response to a fault is determined by a supervisor unit. The method is demonstrated on a full six-degrees-of-freedom nonlinear simulation model of the GTM UAV.

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.

MEMS-Reconfigurable Metamaterials and Antenna Applications

Directory of Open Access Journals (Sweden)

Tomislav Debogovic

2014-01-01

Full Text Available This paper reviews some of our contributions to reconfigurable metamaterials, where dynamic control is enabled by microelectromechanical systems (MEMS technology. First, we show reconfigurable composite right-/left-handed transmission lines (CRLH-TLs having state of the art phase velocity variation and loss, thereby enabling efficient reconfigurable phase shifters and leaky-wave antennas (LWA. Second, we present very low loss metasurface designs with reconfigurable reflection properties, applicable in reflectarrays and partially reflective surface (PRS antennas. All the presented devices have been fabricated and experimentally validated. They operate in X- and Ku-bands.

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...

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.

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.

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...

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.

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.

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.

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

Accelerating artificial intelligence with reconfigurable computing

Science.gov (United States)

Cieszewski, Radoslaw

Reconfigurable computing is emerging as an important area of research in computer architectures and software systems. Many algorithms can be greatly accelerated by placing the computationally intense portions of an algorithm into reconfigurable hardware. Reconfigurable computing combines many benefits of both software and ASIC implementations. Like software, the mapped circuit is flexible, and can be changed over the lifetime of the system. Similar to an ASIC, reconfigurable systems provide a method to map circuits into hardware. Reconfigurable systems therefore have the potential to achieve far greater performance than software as a result of bypassing the fetch-decode-execute operations of traditional processors, and possibly exploiting a greater level of parallelism. Such a field, where there is many different algorithms which can be accelerated, is an artificial intelligence. This paper presents example hardware implementations of Artificial Neural Networks, Genetic Algorithms and Expert Systems.

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.

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.

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

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.

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.

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...

Torsional actuation with extension-torsion composite coupling and a magnetostrictive actuator

Science.gov (United States)

Bothwell, Christopher M.; Chandra, Ramesh; Chopra, Inderjit

1995-04-01

An analytical-experimental study of using magnetostrictive actuators in conjunction with an extension-torsion coupled composite tube to actuate a rotor blade trailing-edge flap to actively control helicopter vibration is presented. Thin walled beam analysis based on Vlasov theory was used to predict the induced twist and extension in a composite tube with magnetostrictive actuation. The study achieved good correlation between theory and experiment. The Kevlar-epoxy systems showed good correlation between measured and predicted twist values.

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.

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...

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.

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.

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.

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.

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

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.

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.

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,...

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.

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

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

Smart film actuators using biomass plastic

International Nuclear Information System (INIS)

Yoneyama, Satoshi; Tanaka, Nobuo

2011-01-01

This paper presents a novel smart film actuator based on the use of a biomass plastic as a piezoelectric film. Conventional polymeric smart sensors and actuators have been based upon synthetic piezoelectric polymer films such as PVDF. Almost all synthetic polymers are made from nearly depleted oil resources. In addition combustion of their materials releases carbon dioxide, thereby contributing to global warming. Thus at least two important sustainability principles are violated when employing synthetic polymers: avoiding depletable resources and avoiding ecosystem destruction. To overcome such problems, industrial plastic products made from synthetic polymers were developed to replace oil-based plastics with biomass plastics. This paper applies a biomass plastic with piezoelectricity such as poly-L-lactic acid (PLLA). As a result, PLLA film becomes a distributed parameter actuator per se, hence an environmentally conscious smart film actuator is developed. Firstly, this paper overviews the fundamental properties of piezoelectric synthetic polymers and biopolymers. The concept of carbon neutrality using biopolymers is mentioned. Then a two-dimensional modal actuator for exciting a specific structural mode is proposed. Furthermore, a biomass plastic-based cantilever beam with the capability of modal actuation is developed, the validity of the proposed smart film actuator based upon a biomass plastic being analytically as well as experimentally verified

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.

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.

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.

Implementation of Reconfigurable Manufacturing Systems, the Case of The LEGO Group

DEFF Research Database (Denmark)

Wang, Ying; Bilberg, Arne; Hadar, Ronen

of reconfigurable manufacturing systems (RMS). A literature review is made to describe the advantages and core characteristics of RMS. Based on the theory, a conceptual model is developed to analyze where RMS would be most suitable and have most benefits in The LEGO Group. Finally, the conclusion is drawn based...... on the analysis through the model. Keywords: Reconfigurable Manufacturing Systems, Conceptual Model of RMS, Production of The LEGO Group...

ETSI-Standard Reconfigurable Mobile Device for Supporting the Licensed Shared Access

Directory of Open Access Journals (Sweden)

Kyunghoon Kim

2016-01-01

Full Text Available In order for a Mobile Device (MD to support the Licensed Shared Access (LSA, the MD should be reconfigurable, meaning that the configuration of a MD must be adaptively changed in accordance with the communication standard adopted in a given LSA system. Based on the standard architecture for reconfigurable MD defined in Working Group (WG 2 of the Technical Committee (TC Reconfigurable Radio System (RRS of the European Telecommunications Standards Institute (ETSI, this paper presents a procedure to transfer control signals among the software entities of a reconfigurable MD required for implementing the LSA. This paper also presents an implementation of a reconfigurable MD prototype that realizes the proposed procedure. The modem and Radio Frequency (RF part of the prototype MD are implemented with the NVIDIA GeForce GTX Titan Graphic Processing Unit (GPU and the Universal Software Radio Peripheral (USRP N210, respectively. With a preset scenario that consists of five time slots from different signal environments, we demonstrate superb performance of the reconfigurable MD in comparison to the conventional nonreconfigurable MD in terms of the data receiving rate available in the LSA band at 2.3–2.4 GHz.

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)

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.

PV Reconfiguration Systems: a Technical and Economic Study

Directory of Open Access Journals (Sweden)

Caruso M.

2017-03-01

Full Text Available Dynamical electrical array reconfiguration strategies for grid-connected PV systems have been proposed as solution to improve energy production due to the mismatch effect of PV plants during partial shading conditions. Strategies are based on the use of dynamic connections between PV panels given by the employment of switches that allow for each panel the series, parallel or exclusion connections, physically changing the electrical connections between the related PV modules, consequentially modifying the layout of the plant. Usually the cost of the dynamic matrix is not taken into account. This novel work evaluates the economic advantages obtained by the use of reconfiguration strategies in PV systems, by taking into consideration the price of energy due to incentives in different European and non-European countries and correlates it with the employment of two types of reconfigurators, with different internal structures. For each of the incentives proposed by the different Countries, the main strength and weakness points of the possible investment are highlighted and critically analyzed. From this analysis, it can be stated that the adoption of reconfiguration systems, in certain cases, can be a very convenient solution.

Reconfigurable Signal Processing and Hardware Architecture for Broadband Wireless Communications

Directory of Open Access Journals (Sweden)

Liang Ying-Chang

2005-01-01

Full Text Available This paper proposes a broadband wireless transceiver which can be reconfigured to any type of cyclic-prefix (CP -based communication systems, including orthogonal frequency-division multiplexing (OFDM, single-carrier cyclic-prefix (SCCP system, multicarrier (MC code-division multiple access (MC-CDMA, MC direct-sequence CDMA (MC-DS-CDMA, CP-based CDMA (CP-CDMA, and CP-based direct-sequence CDMA (CP-DS-CDMA. A hardware platform is proposed and the reusable common blocks in such a transceiver are identified. The emphasis is on the equalizer design for mobile receivers. It is found that after block despreading operation, MC-DS-CDMA and CP-DS-CDMA have the same equalization blocks as OFDM and SCCP systems, respectively, therefore hardware and software sharing is possible for these systems. An attempt has also been made to map the functional reconfigurable transceiver onto the proposed hardware platform. The different functional entities which will be required to perform the reconfiguration and realize the transceiver are explained.

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.

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.

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.

Trustworthy reconfigurable systems enhancing the security capabilities of reconfigurable hardware architectures

CERN Document Server

Feller, Thomas

2014-01-01

?Thomas Feller sheds some light on trust anchor architectures fortrustworthy reconfigurable systems. He is presenting novel concepts enhancing the security capabilities of reconfigurable hardware.Almost invisible to the user, many computer systems are embedded into everyday artifacts, such as cars, ATMs, and pacemakers. The significant growth of this market segment within the recent years enforced a rethinking with respect to the security properties and the trustworthiness of these systems. The trustworthiness of a system in general equates to the integrity of its system components. Hardware-b

Development of thermal actuators with multi-locking positions

Science.gov (United States)

Luo, J. K.; Zhu, Y.; Fu, Y. Q.; Flewitt, A. J.; Spearing, S. M.; Miao, J. M.; Milne, W. I.

2006-04-01

To reduce power consumption and operation temperature for micro-thermal actuators, metal-based micro-mechanical locks with multi-locking positions were analyzed and fabricated. The micro-locks consist of two or three U-shaped thermal actuators. The devices were made by a single mask process using electroplated Ni as the active material. Tests showed that the metal based thermal actuators deliver a maximum displacement of ~20µm at a much lower temperature than that of Si-based actuators. However Ni-actuators showed a severe back bending, which increases with increasing applied power. The temperature to initiate the back bending is as low as ~240°C. Back bending increases the distance between the two actuators, and leads to locking function failure. For practical application, Ni-based thermal actuators must be operated below 200°C.

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...

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.

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.

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.

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.

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

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

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)

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)

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.

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.

Reconfigurable Autonomy for Future Planetary Rovers

Science.gov (United States)

Burroughes, Guy

Extra-terrestrial Planetary rover systems are uniquely remote, placing constraints in regard to communication, environmental uncertainty, and limited physical resources, and requiring a high level of fault tolerance and resistance to hardware degradation. This thesis presents a novel self-reconfiguring autonomous software architecture designed to meet the needs of extraterrestrial planetary environments. At runtime it can safely reconfigure low-level control systems, high-level decisional autonomy systems, and managed software architecture. The architecture can perform automatic Verification and Validation of self-reconfiguration at run-time, and enables a system to be self-optimising, self-protecting, and self-healing. A novel self-monitoring system, which is non-invasive, efficient, tunable, and autonomously deploying, is also presented. The architecture was validated through the use-case of a highly autonomous extra-terrestrial planetary exploration rover. Three major forms of reconfiguration were demonstrated and tested: first, high level adjustment of system internal architecture and goal; second, software module modification; and third, low level alteration of hardware control in response to degradation of hardware and environmental change. The architecture was demonstrated to be robust and effective in a Mars sample return mission use-case testing the operational aspects of a novel, reconfigurable guidance, navigation, and control system for a planetary rover, all operating in concert through a scenario that required reconfiguration of all elements of the system.

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.

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.

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

Elements of Autonomous Self-Reconfigurable Robots

DEFF Research Database (Denmark)

Christensen, David Johan

In this thesis, we study several central elements of autonomous self-reconfigurable modular robots. Unlike conventional robots such robots are: i) Modular, since robots are assembled from numerous robotic modules. ii) Reconfigurable, since the modules can be combined in a variety of ways. iii) Self......-reconfigurable, since the modules themselves are able to change how they are combined. iv) Autonomous, since robots control themselves without human guidance. Such robots are attractive to study since they in theory have several desirable characteristics, such as versatility, reliability and cheapness. In practice...... however, it is challenging to realize such characteristics since state-of-the-art systems and solutions suffer from several inherent technical and theoretical problems and limitations. In this thesis, we address these challenges by exploring four central elements of autonomous self-reconfigurable modular...

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.

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.

Silicon Processors Using Organically Reconfigurable Techniques (SPORT)

Science.gov (United States)

2014-05-19

AFRL-OSR-VA-TR-2014-0132 SILICON PROCESSORS USING ORGANICALLY RECONFIGURABLE TECHNIQUES ( SPORT ) Dennis Prather UNIVERSITY OF DELAWARE Final Report 05...5a. CONTRACT NUMBER Silicon Processes for Organically Reconfigurable Techniques ( SPORT ) 5b. GRANT NUMBER FA9550-10-1-0363 5c...Contract: Silicon Processes for Organically Reconfigurable Techniques ( SPORT ) Contract #: FA9550-10-1-0363 Reporting Period: 1 July 2010 – 31 December

A game-theoretic formulation of the homogeneous self-reconfiguration problem

KAUST Repository

Pickem, Daniel; Egerstedt, Magnus; Shamma, Jeff S.

2015-01-01

In this paper we formulate the homogeneous two- and three-dimensional self-reconfiguration problem over discrete grids as a constrained potential game. We develop a game-theoretic learning algorithm based on the Metropolis-Hastings algorithm that solves the self-reconfiguration problem in a globally optimal fashion. Both a centralized and a fully decentralized algorithm are presented and we show that the only stochastically stable state is the potential function maximizer, i.e. the desired target configuration. These algorithms compute transition probabilities in such a way that even though each agent acts in a self-interested way, the overall collective goal of self-reconfiguration is achieved. Simulation results confirm the feasibility of our approach and show convergence to desired target configurations.

A game-theoretic formulation of the homogeneous self-reconfiguration problem

KAUST Repository

Pickem, Daniel

2015-12-15

In this paper we formulate the homogeneous two- and three-dimensional self-reconfiguration problem over discrete grids as a constrained potential game. We develop a game-theoretic learning algorithm based on the Metropolis-Hastings algorithm that solves the self-reconfiguration problem in a globally optimal fashion. Both a centralized and a fully decentralized algorithm are presented and we show that the only stochastically stable state is the potential function maximizer, i.e. the desired target configuration. These algorithms compute transition probabilities in such a way that even though each agent acts in a self-interested way, the overall collective goal of self-reconfiguration is achieved. Simulation results confirm the feasibility of our approach and show convergence to desired target configurations.

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.

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...

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.

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.

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.

Active joint mechanism driven by multiple actuators made of flexible bags: a proposal of dual structural actuator.

Science.gov (United States)

Kimura, Hitoshi; Matsuzaki, Takuya; Kataoka, Mokutaro; Inou, Norio

2013-01-01

An actuator is required to change its speed and force depending on the situation. Using multiple actuators for one driving axis is one of the possible solutions; however, there is an associated problem of output power matching. This study proposes a new active joint mechanism using multiple actuators. Because the actuator is made of a flexible bag, it does not interfere with other actuators when it is depressurized. The proposed joint achieved coordinated motion of multiple actuators. This report also discusses a new actuator which has dual cylindrical structure. The cylinders are composed of flexible bags with different diameters. The joint torque is estimated based on the following factors: empirical formula for the flexible actuator torque, geometric relationship between the joint and the actuator, and the principle of virtual work. The prototype joint mechanism achieves coordinated motion of multiple actuators for one axis. With this motion, small inner actuator contributes high speed motion, whereas large outer actuator generates high torque. The performance of the prototype joint is examined by speed and torque measurements. The joint showed about 30% efficiency at 2.0 Nm load torque under 0.15 MPa air input.

Method for driving an actuator, actuator drive, and apparatus comprising an actuator

OpenAIRE

2010-01-01

An actuator driver circuit includes a drive signal source and an electrical damping element having a negative resistance connected in series with the drive signal source. A controllable switch is provided for selectively switching the electrical damping element into or put of a signal path from a drive signal source output to a driver circuit output, in order to selectively change the electrical damping of an actuator. For example, the electrical damping of a radial actuator or a focus actuat...

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.

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.

A novel approach to gait synchronization and transition for reconfigurable walking platforms

Directory of Open Access Journals (Sweden)

Shunsuke Nansai

2015-04-01

Full Text Available Legged robots based on one degree-of-freedom reconfigurable planar leg mechanisms, that are capable of generating multiple useful gaits, are highly desired due to the possibility of handling environments and tasks of high complexity while maintaining simple control schemes. An essential consideration in these reconfigurable legged robots is to attain stability in motion, at rest as well as while transforming from one configuration to another with the minimum number of legs as long as the full range of their walking patterns, resulting from the different gait cycles of their legs, is achieved. To this end, in this paper, we present a method for the generation of input joint trajectories to properly synchronize the movement of quadruped robots with reconfigurable legs. The approach is exemplified in a four-legged robot with reconfigurable Jansen legs capable of generating up to six useful different gait cycles. The proposed technique is validated through simulated results that show the platform׳s stability across its six feasible walking patterns and during gait transition phases, thus considerably extending the capabilities of the non-reconfigurable design.

A Domain-Specific Language for Programming Self-Reconfigurable Robots

DEFF Research Database (Denmark)

Schultz, Ulrik Pagh; Christensen, David Johan; Støy, Kasper

2007-01-01

. Programming a modular, self-reconfigurable robot is however a complicated task: the robot is essentially a real-time, distributed embedded system, where control and communication paths often are tightly coupled to the current physical configuration of the robot. To facilitate the task of programming modular......, self-reconfigurable robots, we have developed a declarative, role-based language that allows the programmer to define roles and behavior independently of the concrete physical structure of the robot. Roles are compiled to mobile code fragments that distribute themselves over the physical structure...

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.

Materials challenges for repeatable RF wireless device reconfiguration with microfluidic channels

Science.gov (United States)

Griffin, Anthony S.; Sottos, Nancy R.; White, Scott R.

2018-03-01

Recently, adaptive wireless devices have utilized displacement of EGaIn within microchannels as an electrical switching mechanism to enable reconfigurable electronics. Device reconfiguration using EGaIn in microchannels overcomes many challenges encountered by more traditional reconfiguration mechanisms such as diodes and microelectromechanical systems (MEMS). Reconfiguration using EGaIn is severely limited by undesired permanent shorting due to retention of the liquid in microchannels caused by wetting and rapid oxide skin formation. Here, we investigate the conditions which prevent repeatable electrical switching using EGaIn in microchannels. Initial contact angle tests of EGaIn on epoxy surfaces demonstrate the wettability of EGaIn on flat surfaces. SEM cross-sections of microchannels reveal adhesion of EGaIn residue to channel walls. Micro-computed tomography (microCT) scans of provide volumetric measurements of EGaIn remaining inside channels after flow cycling. Non-wetting coatings are proposed as materials based strategy to overcome these issues in future work.

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.

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.

Reconfiguring Urban Sustainability Transitions, Analysing Multiplicity

Directory of Open Access Journals (Sweden)

Mike Hodson

2017-02-01

Full Text Available Cities, and the networked infrastructures that sustain urban life, are seen as crucial sites for creating more sustainable futures. Yet, although there are many plans, the realisation of sustainable urban infrastructures on the ground is uneven. To develop better ways of understanding why this is the case, the paper makes a conceptual contribution by engaging with current understanding of urban sustainability transitions, using urban sustainable mobility as a reference point. It extends these insights to argue that urban transitions are not about technological or social innovation per se, but about how multiple innovations are experimented with, combined and reconfigured in existing urban contexts and how such processes are governed. There are potentially many ways in which urban sustainable mobility can be reconfigured contextually. Innovation is in the particular form of reconfiguration rather than individual technologies. To make analytical sense of this multiplicity, a preliminary framework is developed that offers the potential to think about urban transitions as contextual and reconfigurational. We argue that there is a need to embrace multiplicity and to understand its relationships to forms of reconfiguration, through empirical exploration and further theoretical and conceptual development. The preliminary framework is a contribution to doing so and we set out future directions for research.

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.

Liquid metal actuation by electrical control of interfacial tension

Energy Technology Data Exchange (ETDEWEB)

Eaker, Collin B.; Dickey, Michael D., E-mail: michael-dickey@ncsu.edu [Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, North Carolina 27695 (United States)

2016-09-15

By combining metallic electrical conductivity with low viscosity, liquid metals and liquid metal alloys offer new and exciting opportunities to serve as reconfigurable components of electronic, microfluidic, and electromagnetic devices. Here, we review the physics and applications of techniques that utilize voltage to manipulate the interfacial tension of liquid metals; such techniques include electrocapillarity, continuous electrowetting, electrowetting-on-dielectric, and electrochemistry. These techniques lower the interfacial tension between liquid metals and a surrounding electrolyte by driving charged species (or in the case of electrochemistry, chemical species) to the interface. The techniques are useful for manipulating and actuating liquid metals at sub-mm length scales where interfacial forces dominate. We focus on metals and alloys that are liquid near or below room temperature (mercury, gallium, and gallium-based alloys). The review includes discussion of mercury—despite its toxicity—because it has been utilized in numerous applications and it offers a way of introducing several phenomena without the complications associated with the oxide layer that forms on gallium and its alloys. The review focuses on the advantages, applications, opportunities, challenges, and limitations of utilizing voltage to control interfacial tension as a method to manipulate liquid metals.

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

The static actuation of dielectric elastomer actuators: how does pre-stretch improve actuation?

International Nuclear Information System (INIS)

Kofod, Guggi

2008-01-01

It has previously been shown that providing dielectric elastomer actuators with a level of pre-stretch can improve properties such as breakdown strength, actuation strain and efficiency. The actuation in such actuators depends on an interplay between the highly nonlinear hyperelastic stress-strain behaviour with the electrostatic Maxwell's stress; however, the direct effects of pre-stretch on the electromechanical coupling have still not been investigated in detail. We compare several experimental results found in the literature on the hyperelastic parameters of the Ogden model for the commonly used material VHB 4910, and introduce a more detailed and thus more accurate fit to a previous uniaxial stress-strain experiment. Electrostatic actuation models for a pure shear cuboid dielectric elastomer actuator with pre-stretch are introduced, for both intensive and extensive variables. For both intensive and extensive variables the constant strain (blocked stress or force) as well as the actuation strain is presented. It is shown how in the particular case of isotropic amorphous elastomers the pre-stretch does not affect the electromechanical coupling directly, and that the enhancement in actuation strain due to pre-stretch occurs through the alteration of the geometrical dimensions of the actuator. Also, the presence of the optimum load is explained as being due to the plateau region in the force-stretch curve, and it is shown that pre-stretch is not able to affect its position. Finally, it is shown how the simplified Ogden fit leads to entirely different conclusions for actuation strain in terms of extensive variables as does the detailed fit, emphasizing the importance of employing accurate hyperelastic models for the stress-stretch behaviour of the elastomer.

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.

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

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.

Distribution grid reconfiguration reduces power losses and helps integrate renewables

International Nuclear Information System (INIS)

Lueken, Colleen; Carvalho, Pedro M.S.; Apt, Jay

2012-01-01

A reconfigurable network can change its topology by opening and closing switches on power lines. We use real wind, solar, load, and cost data and a model of a reconfigurable distribution grid to show that reconfiguration allows a grid operator to reduce operational losses as well as to accept more intermittent renewable generation than a static configuration can. Net present value analysis of automated switch technology shows that the return on investment is negative for this test network when considering only loss reduction, but that the investment is attractive under certain conditions when reconfiguration is used to minimize curtailment. - Highlights: ► Reconfiguration may reduce losses in grids with solar or wind distributed generation. ► Reconfigurable networks can accept more solar or wind DG than static ones. ► Using reconfiguration for loss reduction would not create a positive ROI. ► Using reconfiguration to reduce curtailment usually would create a positive ROI.

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...

From stretchable to reconfigurable inorganic electronics

KAUST Repository

Nassar, Joanna M.

2016-05-06

Today’s state-of-the-art electronics are high performing, energy efficient, multi-functional and cost effective. However, they are also typically rigid and brittle. With the emergence of the Internet of Everything, electronic applications are expanding into previously unexplored areas, like healthcare, smart wearable artifacts, and robotics. One major challenge is the physical asymmetry of target application surfaces, which often cause mechanical stretching, contracting, twisting and other deformations to the application. In this review paper, we explore materials, processes, mechanics and devices that enable physically stretchable and reconfigurable electronics. While the concept of stretchable electronics is commonly used in practice, the notion of physically reconfigurable electronics is still in its infancy. Because organic materials are commonly naturally stretchable and physically deformable, we predominantly focus on electronics made from inorganic materials that have the capacity for physical stretching and reconfiguration while retaining their intended attributes. We emphasize how applications of electronics dictate theory to integration strategy for stretchable and reconfigurable inorganic electronics.

Multimode Communication Protocols Enabling Reconfigurable Radios

Directory of Open Access Journals (Sweden)

Berlemann Lars

2005-01-01

Full Text Available This paper focuses on the realization and application of a generic protocol stack for reconfigurable wireless communication systems. This focus extends the field of software-defined radios which usually concentrates on the physical layer. The generic protocol stack comprises common protocol functionality and behavior which are extended through specific parts of the targeted radio access technology. This paper considers parameterizable modules of basic protocol functions residing in the data link layer of the ISO/OSI model. System-specific functionality of the protocol software is realized through adequate parameterization and composition of the generic modules. The generic protocol stack allows an efficient realization of reconfigurable protocol software and enables a completely reconfigurable wireless communication system. It is a first step from side-by-side realized, preinstalled modes in a terminal towards a dynamic reconfigurable anymode terminal. The presented modules of the generic protocol stack can also be regarded as a toolbox for the accelerated and cost-efficient development of future communication protocols.

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.

El Diseño Modular en el contexto del desarrollo de Máquinas Herramienta Reconfigurables. // Modular Design in the development of reconfigurable Machine Tools´ context.

Directory of Open Access Journals (Sweden)

R. Pérez Rodríguez

2005-05-01

Full Text Available Las tendencias actuales en los procesos de manufactura reflejan los cambios en las demandas de los clientes. En nuestrosdías, el mercado requiere inexorablemente de productos cada vez más personalizados, por lo que se tiende de unaproducción masiva hacia un tipo específico de producción, en menos tiempo y con menos costos de producción. Enrespuesta a esta necesidad, la nueva generación de máquinas herramienta debe de ser reconfigurable e inteligente. Lascaracterísticas principales de las Máquinas Reconfigurables e Inteligentes son la modularidad, convertibilidad, flexibilidady efectividad en los costos. Este artículo presenta un enfoque para el diseño modular de máquinas herramienta, basado en elportafolio de productos del constructor de máquinas. La metodología parte de un conjunto de requerimientos funcionalesdefinidos por el constructor de máquinas y ofrece una descripción de los posibles módulos que pueden ser desarrolladospara una determinada máquina herramienta reconfigurable.Palabras claves: Diseño modular, máquinas herramienta, reconfigurable, inteligente.___________________________________________________________________________Abstract.The manufacturing tendencies reflect the changes on the customer demands. Nowadays, the market is constantly requiringmore customized products, moving from mass production to “one-of-a-kind production” in less time with lower productioncosts. In response to this need, the next generation of machine tools should be reconfigurable and intelligent.Reconfigurability allows for the reduction of machine design lead time, machine set-up and ramp-up time. The principalcharacteristics of the Reconfigurable and Intelligent Machines are modularity, convertibility, flexibility and costeffectiveness.This paper presents an approach for the design of machine tools modules, based on the product portfolio ofthe machine tool builder. The methodology takes as input a set of functional requirements

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.

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.

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

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.

Design, Modelling and Analysis of a Workflow Reconfiguration

DEFF Research Database (Denmark)

Mazzara, Manuel; Abouzaid, Faisal; Dragoni, Nicola

2011-01-01

This paper describes a case study involving the reconfiguration of an office workflow. We state the requirements on a system implementing the workflow and its reconfiguration, and describe the system’s design in BPMN. We then use an asynchronous pi-calculus and Web.1 to model the design and to ve......This paper describes a case study involving the reconfiguration of an office workflow. We state the requirements on a system implementing the workflow and its reconfiguration, and describe the system’s design in BPMN. We then use an asynchronous pi-calculus and Web.1 to model the design...

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...

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

A reconfigurable strategy for distributed digital process control

International Nuclear Information System (INIS)

Garcia, H.E.; Ray, A.; Edwards, R.M.

1990-01-01

A reconfigurable control scheme is proposed which, unlike a preprogrammed one, uses stochastic automata to learn the current operating status of the environment (i.e., the plant, controller, and communication network) by dynamically monitoring the system performance and then switching to the appropriate controller on the basis of these observations. The potential applicability of this reconfigurable control scheme to electric power plants is being investigated. The plant under consideration is the Experimental Breeder Reactor (EBR-II) at the Argonne National Laboratory site in Idaho. The distributed control system is emulated on a ring network where the individual subsystems are hosted as follows: (1) the reconfigurable control modules are located in one of the network modules called Multifunction Controller; (2) the learning modules are resident in a VAX 11/785 mainframe computer; and (3) a detailed model of the plant under control is executed in the same mainframe. This configuration is a true representation of the network-based control system in the sense that it operates in real time and is capable of interacting with the actual plant

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).

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)

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

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.

Optimization of metallic microheaters for high-speed reconfigurable silicon photonics.

Science.gov (United States)

Atabaki, A H; Shah Hosseini, E; Eftekhar, A A; Yegnanarayanan, S; Adibi, A

2010-08-16

The strong thermooptic effect in silicon enables low-power and low-loss reconfiguration of large-scale silicon photonics. Thermal reconfiguration through the integration of metallic microheaters has been one of the more widely used reconfiguration techniques in silicon photonics. In this paper, structural and material optimizations are carried out through heat transport modeling to improve the reconfiguration speed of such devices, and the results are experimentally verified. Around 4 micros reconfiguration time are shown for the optimized structures. Moreover, sub-microsecond reconfiguration time is experimentally demonstrated through the pulsed excitation of the microheaters. The limitation of this pulsed excitation scheme is also discussed through an accurate system-level model developed for the microheater response.

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.

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

Validation of multi-body modelling methodology for reconfigurable underwater robots

DEFF Research Database (Denmark)

Nielsen, M.C.; Eidsvik, O. A.; Blanke, Mogens

2016-01-01

This paper investigates the problem of employing reconfigurable robots in an underwater setting. The main results presented is the experimental validation of a modelling methodology for a system consisting of N dynamically connected robots with heterogeneous dynamics. Two distinct types...... of experiments are performed, a series of hydrostatic free-decay tests and a series of open-loop trajectory tests. The results are compared to a simulation based on the modelling methodology. The modelling methodology shows promising results for usage with systems composed of reconfigurable underwater modules...

Multi-mode sensor processing on a dynamically reconfigurable massively parallel processor array

Science.gov (United States)

Chen, Paul; Butts, Mike; Budlong, Brad; Wasson, Paul

2008-04-01

This paper introduces a novel computing architecture that can be reconfigured in real time to adapt on demand to multi-mode sensor platforms' dynamic computational and functional requirements. This 1 teraOPS reconfigurable Massively Parallel Processor Array (MPPA) has 336 32-bit processors. The programmable 32-bit communication fabric provides streamlined inter-processor connections with deterministically high performance. Software programmability, scalability, ease of use, and fast reconfiguration time (ranging from microseconds to milliseconds) are the most significant advantages over FPGAs and DSPs. This paper introduces the MPPA architecture, its programming model, and methods of reconfigurability. An MPPA platform for reconfigurable computing is based on a structural object programming model. Objects are software programs running concurrently on hundreds of 32-bit RISC processors and memories. They exchange data and control through a network of self-synchronizing channels. A common application design pattern on this platform, called a work farm, is a parallel set of worker objects, with one input and one output stream. Statically configured work farms with homogeneous and heterogeneous sets of workers have been used in video compression and decompression, network processing, and graphics applications.

Microwave photonic filters using low-cost sources featuring tunability, reconfigurability and negative coefficients.

Science.gov (United States)

Capmany, José; Mora, José; Ortega, Beatriz; Pastor, Daniel

2005-03-07

We propose and experimentally demonstrate two configurations of photonic filters for the processing of microwave signals featuring tunability, reconfigurability and negative coefficients based on the use of low cost optical sources. The first option is a low power configuration based on spectral slicing of a broadband source. The second is a high power configuration based on fixed lasers. Tunability, reconfigurability and negative coefficients are achieved by means of a MEMS cross-connect, a variable optical attenuator array and simple 2x2 switches respectively.

Electromechanical actuation of buckypaper actuator: Material properties and performance relationships

International Nuclear Information System (INIS)

Cottinet, P.-J.; Souders, C.; Tsai, S.-Y.; Liang, R.; Wang, B.; Zhang, C.

2012-01-01

Carbon nanotubes can be assembled into macroscopic thin film materials called buckypapers. To incorporate buckypaper actuators into engineering systems, it is of high importance to understand their material property-actuation performance relationships in order to model and predict the behavior of these actuators. The electromechanical actuation of macroscopic buckypaper structures and their actuators, including single and multi-walled carbon nanotube buckypapers and aligned single-walled nanotube buckypapers, were analyzed and compared. From the experimental evidence, this Letter discusses the effects of the fundamental material properties, including Young modulus and electrical double layer properties, on actuation performance of the resultant actuators. -- Highlights: ► In this study we identified the figure of merit of the electromechanical conversion. ► Different type of buckypaper was realized and characterized for actuation properties. ► The results demonstrated the potential of Buckypapers/Nafion for actuation

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...

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...

Design and demonstration of a fish robot actuated by a SMA-driven actuation system

Science.gov (United States)

Le, Chan H.; Nguyen, Quang S.; Park, Hoon C.

2010-04-01

This paper presents a concept of a fish robot actuated by an SMA-based actuator. The bending-type actuator system is composed of a 0.1mm diameter SMA wire and a 0.5mm thick glass/epoxy strip. The SMA wire is installed to the bent composite strip. The actuator can produce about 200gf of blocking force and 3.5mm displacement at the center of the glass/epoxy strip. The bending motion of the actuator is converted into the tail-beat motion of a fish robot through a linkage system. The fish robot is evaluated by measuring the tail-beat angle, swimming speed and thrust produced by the fish robot. The tail-beat angle is about 20° and the maximum swimming speed is about 1.6cm/s. The measured thrust is about 0.4gf when the fish robot is operated at 0.9Hz.

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

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.

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)

Development of a dry actuation conducting polymer actuator for micro-optical zoom lenses

Science.gov (United States)

Kim, Baek-Chul; Kim, Hyunseok; Nguyen, H. C.; Cho, M. S.; Lee, Y.; Nam, Jae-Do; Choi, Hyouk Ryeol; Koo, J. C.; Jeong, H.-S.

2008-03-01

The objective of the present work is to demonstrate the efficiency and feasibility of NBR (Nitrile Butadiene Rubber) based conducting polymer actuator that is fabricated into a micro zoon lens driver. Unlike the traditional conducting polymer that normally operates in a liquid, the proposed actuator successfully provides fairly effective driving performance for the zoom lens system in a dry environment. And this paper is including the experiment results for an efficiency improvement. The result suggested by an experiment was efficient in micro optical zoom lens system. In addition, the developed design method of actuator was given consideration to design the system.

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.

Piezoelectric Actuator/Sensor Technology at Rockwell

Science.gov (United States)

Neurgaonkar, Ratnakar R.

1996-01-01

We describe the state-of-the art of piezoelectric materials based on perovskite and tungsten bronze families for sensor, actuator and smart structure applications. The microstructural defects in these materials have been eliminated to a large extent and the resulting materials exhibit exceedingly high performance for various applications. The performance of Rockwell actuators/sensors is at least 3 times better than commercially available products. These high performance actuators are being incorporated into various applications including, DOD, NASA and commercial. The multilayer actuator stacks fabricated from our piezoceramics are advantageous for sensing and high capacitance applications. In this presentation, we will describe the use of our high performance piezo-ceramics for actuators and sensors, including multilayer stacks and composite structures.

Actuator with Multi Degrees of Freedom(Actuator)

OpenAIRE

矢野, 智昭; Tomoaki, YANO; 産業技術総合研究所

2006-01-01

The advantages, problems and the recent developments of the actuator with multi degrees of freedom are presented. At first, the advantages of the actuator with multi degrees of freedom are described. Next, the problems needed to solve for practical use are presented. The recent applications of the actuator with multi degrees of freedom are also reviewed.

Compact, planar, translational piezoelectric bimorph actuator with Archimedes’ spiral actuating tethers

International Nuclear Information System (INIS)

Yang, Chenye; Liu, Sanwei; Livermore, Carol; Xie, Xin

2016-01-01

The design, analytical modelling, finite element analysis (FEA), and experimental characterization of a microelectromechanical system (MEMS) out-of-plane (vertical) translational piezoelectric lead–zirconate–titanate (PZT) bimorph actuator supported on Archimedes’ spiral tethers are presented. Three types of bimorph actuators with different electrode patterns (with spiral tethers half actuated, fully actuated with uniform polarity, or fully actuated with reversed polarity) are designed and modelled. The two actuators with the highest predicted performance (half actuated and fully actuated with uniform polarity) are implemented and characterized. Both designs are fabricated by commercial processes and are compatible with integration into more complex MEMS systems. Analytical modelling and FEA are used to analyze and predict the actuators’ displacements and blocking forces. Experimental measurements of the deflections and blocking forces of actuators with full uniform actuation and half actuation validate the design. At an applied voltage of 110 V, the out-of-plane deflections of the actuators with half actuation and full uniform actuation are measured at about 17 µ m and 29 µ m respectively, in good agreement with analytical predictions of 17.3 µ m and 34.2 µ m and FEA predictions of 17.1 µ m and 25.8 µ m. The blocking force for devices with half-actuated tethers is predicted to be 12 mN (analytical) and 10 mN (FEA), close to the experimental value of 9 mN. The blocking force for devices with full uniform actuation is predicted to be 23 mN (analytical) and 17 mN (FEA), as compared with 15 mN in experiments. (paper)

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

Analytical dynamic modeling of fast trilayer polypyrrole bending actuators

International Nuclear Information System (INIS)

Amiri Moghadam, Amir Ali; Moavenian, Majid; Tahani, Masoud; Torabi, Keivan

2011-01-01

Analytical modeling of conjugated polymer actuators with complicated electro-chemo-mechanical dynamics is an interesting area for research, due to the wide range of applications including biomimetic robots and biomedical devices. Although there have been extensive reports on modeling the electrochemical dynamics of polypyrrole (PPy) bending actuators, mechanical dynamics modeling of the actuators remains unexplored. PPy actuators can operate with low voltage while producing large displacement in comparison to robotic joints, they do not have friction or backlash, but they suffer from some disadvantages such as creep and hysteresis. In this paper, a complete analytical dynamic model for fast trilayer polypyrrole bending actuators has been proposed and named the analytical multi-domain dynamic actuator (AMDDA) model. First an electrical admittance model of the actuator will be obtained based on a distributed RC line; subsequently a proper mechanical dynamic model will be derived, based on Hamilton's principle. The purposed modeling approach will be validated based on recently published experimental results

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

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.

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)

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.

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

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...

Go reconfigure: how fish change shape as they swim and evolve.

Science.gov (United States)

Long, John H; Porter, Marianne E; Root, Robert G; Liew, Chun Wai

2010-12-01

The bodies of fish change shape over propulsive, behavioral, developmental, and evolutionary time scales, a general phenomenon that we call "reconfiguration". Undulatory, postural, and form-reconfiguration can be distinguished, studied independently, and examined in terms of mechanical interactions and evolutionary importance. Using a combination of live, swimming fishes and digital robotic fish that are autonomous and self-propelled, we examined the functional relation between undulatory and postural reconfiguration in forward swimming, backward swimming, and yaw turning. To probe how postural and form reconfiguration interact, the yaw turning of leopard sharks was examined using morphometric and kinematic analyses. To test how undulatory reconfiguration might evolve, the digital robotic fish were subjected to selection for enhanced performance in a simulated ecology in which each individual had to detect and move towards a food source. In addition to the general issue of reconfiguration, these investigations are united by the fact that the dynamics of undulatory and postural reconfigurations are predicted to be determined, in part, by the structural stiffness of the fish's body. Our method defines undulatory reconfiguration as the combined, point-by-point periodic motion of the body, leaving postural reconfiguration as the combined deviations from undulatory reconfiguration. While undulatory reconfiguration appears to be the sole or primary propulsive driver, postural reconfiguration may contribute to propulsion in hagfish and it is correlated with differences in forward, and backward, swimming in lamprey. Form reconfigures over developmental time in leopard sharks in a manner that is consistent with an allometric scaling theory in which structural stiffness of the body is held constant. However, correlation of a form proxy for structural stiffness of the body suggests that body stiffness may scale in order to limit maximum postural reconfiguration during routine

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)

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

Robust reconfigurable control for parametric and additive faults with FDI uncertainties

DEFF Research Database (Denmark)

Stoustrup, Jakob; Yang, Zhenyu

2000-01-01

From the system recoverable point of view, this paper discusses robust reconfigurable control synthesis for LTI systems and a class of nonlinear control systems with parametric and additive faults as well as derivations generated by FDI algorithms. By following the model-matching strategy......, an augmented optimal control problem is constructed based on the considered faulty and fictitious nominal systems, such that the robust control design techniques, such as H-infinity control and mu synthesis, can be employed for the reconfigurable control design....

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)

Nanopatterned reconfigurable spin-textures for magnonics

Science.gov (United States)

Albisetti, E.; Petti, D.; Pancaldi, M.; Madami, M.; Tacchi, S.; Curtis, J.; King, W. P.; Papp, A.; Csaba, G.; Porod, W.; Vavassori, P.; Riedo, E.; Bertacco, R.

The control of spin-waves holds the promise to enable energy-efficient information transport and wave-based computing. Conventionally, the engineering of spin-waves is achieved via physically patterning magnetic structures such as magnonic crystals and micro-nanowires. We demonstrate a new concept for creating reconfigurable magnonic nanostructures, by crafting at the nanoscale the magnetic anisotropy landscape of a ferromagnet exchange-coupled to an antiferromagnet. By performing a highly localized field cooling with the hot tip of a scanning probe microscope, magnetic structures, with arbitrarily oriented magnetization and tunable unidirectional anisotropy, are patterned without modifying the film chemistry and topography. We demonstrate that, in such structures, the spin-wave excitation and propagation can be spatially controlled at remanence, and can be tuned by external magnetic fields. This opens the way to the use of nanopatterned spin-textures, such as domains and domain walls, for exciting and manipulating magnons in reconfigurable nanocircuits. Partially funded by the EC through project SWING (no. 705326).

MT-ADRES: Multithreading on Coarse-Grained Reconfigurable Architecture

DEFF Research Database (Denmark)

Wu, Kehuai; Kanstein, Andreas; Madsen, Jan

2007-01-01

The coarse-grained reconfigurable architecture ADRES (Architecture for Dynamically Reconfigurable Embedded Systems) and its compiler offer high instruction-level parallelism (ILP) to applications by means of a sparsely interconnected array of functional units and register files. As high-ILP archi......The coarse-grained reconfigurable architecture ADRES (Architecture for Dynamically Reconfigurable Embedded Systems) and its compiler offer high instruction-level parallelism (ILP) to applications by means of a sparsely interconnected array of functional units and register files. As high......-ILP architectures achieve only low parallelism when executing partially sequential code segments, which is also known as Amdahl’s law, this paper proposes to extend ADRES to MT-ADRES (Multi-Threaded ADRES) to also exploit thread-level parallelism. On MT-ADRES architectures, the array can be partitioned in multiple...

A finite element model of rigid body structures actuated by dielectric elastomer actuators

Science.gov (United States)

Simone, F.; Linnebach, P.; Rizzello, G.; Seelecke, S.

2018-06-01

This paper presents on finite element (FE) modeling and simulation of dielectric elastomer actuators (DEAs) coupled with articulated structures. DEAs have proven to represent an effective transduction technology for the realization of large deformation, low-power consuming, and fast mechatronic actuators. However, the complex dynamic behavior of the material, characterized by nonlinearities and rate-dependent phenomena, makes it difficult to accurately model and design DEA systems. The problem is further complicated in case the DEA is used to activate articulated structures, which increase both system complexity and implementation effort of numerical simulation models. In this paper, we present a model based tool which allows to effectively implement and simulate complex articulated systems actuated by DEAs. A first prototype of a compact switch actuated by DEA membranes is chosen as reference study to introduce the methodology. The commercially available FE software COMSOL is used for implementing and coupling a physics-based dynamic model of the DEA with the external structure, i.e., the switch. The model is then experimentally calibrated and validated in both quasi-static and dynamic loading conditions. Finally, preliminary results on how to use the simulation tool to optimize the design are presented.

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

The effects of additives on the actuating performances of a dielectric elastomer actuator

International Nuclear Information System (INIS)

Nguyen, Huu Chuc; Doan, Vu Thuy; Park, JongKil; Koo, Ja Choon; Choi, Hyouk Ryeol; Lee, Youngkwan; Nam, Jae-do

2009-01-01

This paper presents a comprehensive study of the effects of additives on the performance of a dielectric elastomer actuator. Previously, a new dielectric elastomer material, called 'synthetic elastomer', was presented for the means of actuation, which permits changes in the mechanical as well as the electrical properties in order to meet the requirements of certain applications. This work studies how the electromechanical properties of the synthetic elastomer can be adjusted by combining two additives, namely dioctyl phthalate (DOP) and titanium dioxide (TiO 2 ). Experiments are carried out and the effects of each additive are compared to one another based on the actuation performances

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.

Micro-mechanics of ionic electroactive polymer actuators

Science.gov (United States)

Punning, Andres; Põldsalu, Inga; Kaasik, Friedrich; Vunder, Veiko; Aabloo, Alvo

2015-04-01

Commonly, modeling of the bending behavior of the ionic electroactive polymer (IEAP) actuators is based on the classical mechanics of cantilever beam. It is acknowledged, that the actuation of the ionic electroactive polymer (IEAP) actuators is symmetric about the centroid - the convex side of the actuator is expanding and the concave side is contracting for exactly the same amount, while the thickness of the actuator remains invariant. Actuating the IEAP actuators and sensors under scanning electron microscope (SEM), in situ, reveals that for some types of them this approach is incorrect. Comparison of the SEM micrographs using the Digital Image Correction (DIC) method results with the precise strain distribution of the IEAP actuators in two directions: in the axial direction, and in the direction of thickness. This information, in turn, points to the physical processes taking place within the electrodes as well as membrane of the trilayer laminate of sub-millimeter thickness. Comparison of the EAP materials, engaged as an actuator as well as a sensor, reveals considerable differences between the micro-mechanics of the two modes.

A 16-channel reconfigurable OCDMA/DWDM system using continuous phase-shift SSFBGs

OpenAIRE

Chun, Tian; Zhang, Zhaowei; Ibsen, M.; Petropoulos, P.; Richardson, D.J.

2007-01-01

We demonstrate a reconfigurable 16-channel optical code-division multiple access (OCDMA)/dense wavelength division multiplexing (DWDM) system (4 OCDMA times 4 DWDM times 625 Mb/s) based on novel 31-chip, 40 Gchip/s quaternary phase coding gratings operating at a channel spacing of just 50 GHz. The system performance is studied for cases of both fixed and code-reconfigurable decoders. Error-free performance is achieved in both cases and for all 16 channels.

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.

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...

Multi-objective optimal operation of smart reconfigurable distribution grids

Directory of Open Access Journals (Sweden)

Abdollah Kavousi-Fard

2016-02-01

Full Text Available Reconfiguration is a valuable technique that can support the distribution grid from different aspects such as operation cost and loss reduction, reliability improvement, and voltage stability enhancement. An intelligent and efficient optimization framework, however, is required to reach the desired efficiency through the reconfiguration strategy. This paper proposes a new multi-objective optimization model to make use of the reconfiguration strategy for minimizing the power losses, improving the voltage profile, and enhancing the load balance in distribution grids. The proposed model employs the min-max fuzzy approach to find the most satisfying solution from a set of nondominated solutions in the problem space. Due to the high complexity and the discrete nature of the proposed model, a new optimization method based on harmony search (HS algorithm is further proposed. Moreover, a new modification method is suggested to increase the harmony memory diversity in the improvisation stage and increase the convergence ability of the algorithm. The feasibility and satisfying performance of the proposed model are examined on the IEEE 32-bus distribution system.

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.

Modular reconfigurable machine tools: design, control and evaluation

CSIR Research Space (South Africa)

Padayachee, J

2009-11-01

Full Text Available The reconfigurable manufacturing system (RMS) paradigm encapsulates methodologies that enable manufacturing systems to cope effectively with market and product changes. This research presents the design and evaluation of modular reconfigurable...

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.

3rd IEEE/IFToMM International Conference on Reconfigurable Mechanisms and Robots

CERN Document Server

Kong, Xianwen; Dai, Jian; ReMAR 2015; Advances in Reconfigurable Mechanisms and Robots II

2016-01-01

This book presents the most recent advances in the research and applications of reconfigurable mechanisms and robots. It collects 93 independently reviewed papers presented at the Third ASME/IFToMM International Conference on Reconfigurable Mechanisms and Robots (ReMAR 2015) held in Beijing, China, 20-22 July 2015. The conference papers are organized into seven parts to cover the reconfiguration theory, topology, kinematics and design of reconfigurable mechanisms including reconfigurable parallel mechanisms. The most recent results on reconfigurable robots are presented including their analysis, design, simulation and control. Bio-inspired mechanisms are also explored in the challenging fields of rehabilitation and minimally invasive surgery. This book further addresses deployable mechanisms and origami-inspired mechanisms and showcases a wide range of successful applications of reconfigurable mechanisms and robots. Advances in Reconfigurable Mechanisms and Robots II should be of interest for researchers, eng...

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.

Improving Reliability, Security, and Efficiency of Reconfigurable Hardware Systems (Habilitation)

NARCIS (Netherlands)

Ziener, Daniel

2017-01-01

In this treatise,  my research on methods to improve efficiency, reliability, and security of reconfigurable hardware systems, i.e., FPGAs, through partial dynamic reconfiguration is outlined. The efficiency of reconfigurable systems can be improved by loading optimized data paths on-the-fly on an

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.

Exact analysis of two kinds of piezoelectric actuator

International Nuclear Information System (INIS)

Han Rong; Shi Zhifei

2008-01-01

Two kinds of piezoelectric hollow cylinder actuator are studied in this paper. One is the expansion actuator and the other is the contraction actuator. Using the Airy stress function method, the analytical solutions of these two kinds of actuators are obtained based on the theory of piezo-elasticity. The solutions are compared with numerical results and good agreement is found. Inherent properties of these two kinds of piezoelectric cylinder actuator are presented and discussed. Findings have applications in the field of micromechanics and microengineering

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.

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

Micromachined tunable metamaterials: a review

International Nuclear Information System (INIS)

Liu, A Q; Zhu, W M; Tsai, D P; Zheludev, N I

2012-01-01

This paper reviews micromachined tunable metamaterials, whereby the tuning capabilities are based on the mechanical reconfiguration of the lattice and/or the metamaterial element geometry. The primary focus of this review is the feasibility of the realization of micromachined tunable metamaterials via structure reconfiguration and the current state of the art in the fabrication technologies of structurally reconfigurable metamaterial elements. The micromachined reconfigurable microstructures not only offer a new tuning method for metamaterials without being limited by the nonlinearity of constituent materials, but also enable a new paradigm of reconfigurable metamaterial-based devices with mechanical actuations. With recent development in nanomachining technology, it is possible to develop structurally reconfigurable metamaterials with faster tuning speed, higher density of integration and more flexible choice of the working frequencies. (review article)

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.

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...

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

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).

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

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.

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

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...

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.

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

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.

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

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.

Piezoelectric Actuator with Frequency Characteristics for a Middle-Ear Implant.

Science.gov (United States)

Shin, Dong Ho; Cho, Jin-Ho

2018-05-24

The design and implementation of a novel piezoelectric-based actuator for an implantable middle-ear hearing aid is described in this paper. The proposed actuator has excellent low-frequency output characteristics, and can generate high output in a specific frequency band by adjusting the mechanical resonance. The actuator consists of a piezoelectric element, a miniature bellows, a cantilever membrane, a metal ring support, a ceramic tip, and titanium housing. The optimal structure of the cantilever-membrane design, which determines the frequency characteristics of the piezoelectric actuator, was derived through finite element analysis. Based on the results, the piezoelectric actuator was implemented, and its performance was verified through a cadaveric experiment. It was confirmed that the proposed actuator provides better performance than currently used actuators, in terms of frequency characteristics.

3D printed soft parallel actuator

Science.gov (United States)

Zolfagharian, Ali; Kouzani, Abbas Z.; Khoo, Sui Yang; Noshadi, Amin; Kaynak, Akif

2018-04-01

This paper presents a 3-dimensional (3D) printed soft parallel contactless actuator for the first time. The actuator involves an electro-responsive parallel mechanism made of two segments namely active chain and passive chain both 3D printed. The active chain is attached to the ground from one end and constitutes two actuator links made of responsive hydrogel. The passive chain, on the other hand, is attached to the active chain from one end and consists of two rigid links made of polymer. The actuator links are printed using an extrusion-based 3D-Bioplotter with polyelectrolyte hydrogel as printer ink. The rigid links are also printed by a 3D fused deposition modelling (FDM) printer with acrylonitrile butadiene styrene (ABS) as print material. The kinematics model of the soft parallel actuator is derived via transformation matrices notations to simulate and determine the workspace of the actuator. The printed soft parallel actuator is then immersed into NaOH solution with specific voltage applied to it via two contactless electrodes. The experimental data is then collected and used to develop a parametric model to estimate the end-effector position and regulate kinematics model in response to specific input voltage over time. It is observed that the electroactive actuator demonstrates expected behaviour according to the simulation of its kinematics model. The use of 3D printing for the fabrication of parallel soft actuators opens a new chapter in manufacturing sophisticated soft actuators with high dexterity and mechanical robustness for biomedical applications such as cell manipulation and drug release.

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.

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.

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.

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.

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.

Soft Robotic Actuators

Science.gov (United States)

Godfrey, Juleon Taylor

In this thesis a survey on soft robotic actuators is conducted. The actuators are classified into three main categories: Pneumatic Artificial Muscles (PAM), Electronic Electroactive Polymers (Electric EAP), and Ionic Electroactive Polymers (Ionic EAP). Soft robots can have many degrees and are more compliant than hard robots. This makes them suitable for applications that are difficult for hard robots. For each actuator background history, build materials, how they operate, and modeling are presented. Multiple actuators in each class are reviewed highlighting both their use and their mathematical formulation. In addition to the survey the McKibben actuator was chosen for fabrication and in-depth experimental analysis. Four McKibben actuators were fabricated using mesh sleeve, barbed hose fittings, and different elastic bladders. All were actuated using compressed air. Tensile tests were performed for each actuator to measure the tension force as air pressure increased from 20 to 100 psi in 10 psi increments. To account for material relaxation properties eleven trials for each actuator were run for 2-3 days. In conclusion, the smallest outer diameter elastic bladder was capable of producing the highest force due to the larger gap between the bladder and the sleeve.

A Domain-Specific Language for Programming Self-Reconfigurable Robots

DEFF Research Database (Denmark)

Schultz, Ulrik Pagh; Christensen, David Johan; Støy, Kasper

2007-01-01

, self-reconfigurable robots, we have developed a declarative, role-based language that allows the programmer to define roles and behavior independently of the concrete physical structure of the robot. Roles are compiled to mobile code fragments that distribute themselves over the physical structure...

A Workload-Adaptive and Reconfigurable Bus Architecture for Multicore Processors

Directory of Open Access Journals (Sweden)

Shoaib Akram

2010-01-01

Full Text Available Interconnection networks for multicore processors are traditionally designed to serve a diversity of workloads. However, different workloads or even different execution phases of the same workload may benefit from different interconnect configurations. In this paper, we first motivate the need for workload-adaptive interconnection networks. Subsequently, we describe an interconnection network framework based on reconfigurable switches for use in medium-scale (up to 32 cores shared memory multicore processors. Our cost-effective reconfigurable interconnection network is implemented on a traditional shared bus interconnect with snoopy-based coherence, and it enables improved multicore performance. The proposed interconnect architecture distributes the cores of the processor into clusters with reconfigurable logic between clusters to support workload-adaptive policies for inter-cluster communication. Our interconnection scheme is complemented by interconnect-aware scheduling and additional interconnect optimizations which help boost the performance of multiprogramming and multithreaded workloads. We provide experimental results that show that the overall throughput of multiprogramming workloads (consisting of two and four programs can be improved by up to 60% with our configurable bus architecture. Similar gains can be achieved also for multithreaded applications as shown by further experiments. Finally, we present the performance sensitivity of the proposed interconnect architecture on shared memory bandwidth availability.

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

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

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

Natural fibres actuators for smart bio-inspired hygromorph biocomposites

Science.gov (United States)

Le Duigou, Antoine; Requile, Samuel; Beaugrand, Johnny; Scarpa, Fabrizio; Castro, Mickael

2017-12-01

Hygromorph biocomposite (HBC) actuators make use of the transport properties of plant fibres to generate an out-of-plane displacement when a moisture gradient is present. HBC actuators possess a design based on the bilayer configuration of natural hygromorph actuators (like pine cone, wheat awn, Selaginella lepidophyll). In this work we present a series of design guidelines for HBCs with improved performance, low environmental footprints and high durability in severe environments. We develop a theoretical actuating response (curvature) formulation of maleic anhydride polypropylene (MAPP)/plant fibres based on bimetallic actuators theory. The actuation response is evaluated as a function of the fibre type (flax, jute, kenaf and coir). We demonstrate that the actuation is directly related to the fibre microstructure and its biochemical composition. The jute and flax fibres appear to be the best candidates for use in HBCs. Flax/MAPP and jute/MAPP HBCs exhibit similar actuating behaviours during the sorption phase (amplitude and speed), but different desorption characteristics due to the combined effect of the lumen size, fibre division and biochemical composition on the desorption mechanism. During hygromechanical fatigue tests the jute/MAPP HBCs exhibit a drastic improvement in durability compared to their flax counterparts. We also provide a demonstration on how HBCs can be used to trigger deployment of more complex structures based on Origami and Kirigami designs.

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.

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...

Reconfiguring The Supply Chain For Complex Engineered Products

DEFF Research Database (Denmark)

Wæhrens, Brian Vejrum; Asmussen, Jesper Normann

2016-01-01

of the SC, the product and market requirements. This paper seeks to investigate the factors which create a need for supply chain reconfiguration in the context of the Complex Product Systems, together with the enablers and barriers for successfully realizing supply chain improvements through reconfiguration....

MT-ADRES: multi-threading on coarse-grained reconfigurable architecture

DEFF Research Database (Denmark)

Wu, Kehuai; Kanstein, Andreas; Madsen, Jan

2008-01-01

The coarse-grained reconfigurable architecture ADRES (architecture for dynamically reconfigurable embedded systems) and its compiler offer high instruction-level parallelism (ILP) to applications by means of a sparsely interconnected array of functional units and register files. As high-ILP archi......The coarse-grained reconfigurable architecture ADRES (architecture for dynamically reconfigurable embedded systems) and its compiler offer high instruction-level parallelism (ILP) to applications by means of a sparsely interconnected array of functional units and register files. As high......-ILP architectures achieve only low parallelism when executing partially sequential code segments, which is also known as Amdahl's law, this article proposes to extend ADRES to MT-ADRES (multi-threaded ADRES) to also exploit thread-level parallelism. On MT-ADRES architectures, the array can be partitioned...

Nonlinear Tracking Control of a Conductive Supercoiled Polymer Actuator.

Science.gov (United States)

Luong, Tuan Anh; Cho, Kyeong Ho; Song, Min Geun; Koo, Ja Choon; Choi, Hyouk Ryeol; Moon, Hyungpil

2018-04-01

Artificial muscle actuators made from commercial nylon fishing lines have been recently introduced and shown as a new type of actuator with high performance. However, the actuators also exhibit significant nonlinearities, which make them difficult to control, especially in precise trajectory-tracking applications. In this article, we present a nonlinear mathematical model of a conductive supercoiled polymer (SCP) actuator driven by Joule heating for model-based feedback controls. Our efforts include modeling of the hysteresis behavior of the actuator. Based on nonlinear modeling, we design a sliding mode controller for SCP actuator-driven manipulators. The system with proposed control law is proven to be asymptotically stable using the Lyapunov theory. The control performance of the proposed method is evaluated experimentally and compared with that of a proportional-integral-derivative (PID) controller through one-degree-of-freedom SCP actuator-driven manipulators. Experimental results show that the proposed controller's performance is superior to that of a PID controller, such as the tracking errors are nearly 10 times smaller compared with those of a PID controller, and it is more robust to external disturbances such as sensor noise and actuator modeling error.

Operating System Concepts for Reconfigurable Computing: Review and Survey

OpenAIRE

Marcel Eckert; Dominik Meyer; Jan Haase; Bernd Klauer

2016-01-01

One of the key future challenges for reconfigurable computing is to enable higher design productivity and a more easy way to use reconfigurable computing systems for users that are unfamiliar with the underlying concepts. One way of doing this is to provide standardization and abstraction, usually supported and enforced by an operating system. This article gives historical review and a summary on ideas and key concepts to include reconfigurable computing aspects in operating systems. The arti...

Parameters design of the dielectric elastomer spring-roll bending actuator (Conference Presentation)

Science.gov (United States)

Li, Jinrong; Liu, Liwu; Liu, Yanju; Leng, Jinsong

2017-04-01

Dielectric elastomers are novel soft smart material that could deform sustainably when subjected to external electric field. That makes dielectric elastomers promising materials for actuators. In this paper, a spring-roll actuator that would bend when a high voltage is applied was fabricated based on dielectric elastomer. Using such actuators as active parts, the flexible grippers and inchworm-inspired crawling robots were manufactured, which demonstrated some examples of applications in soft robotics. To guide the parameters design of dielectric elastomer based spring-roll bending actuators, the theoretical model of such actuators was established based on thermodynamic theories. The initial deformation and electrical induced bending angle of actuators were formulated. The failure of actuators was also analyzed considering some typical failure modes like electromechanical instability, electrical breakdown, loss of tension and maximum tolerant stretch. Thus the allowable region of actuators was determined. Then the bending angle-voltage relations and failure voltages of actuators with different parameters, including stretches of the dielectric elastomer film, number of active layers, and dimensions of spring, were investigated. The influences of each parameter on the actuator performances were discussed, providing meaningful guidance to the optical design of the spring-roll bending actuators.

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....

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.

A small biomimetic quadruped robot driven by multistacked dielectric elastomer actuators

Science.gov (United States)

Nguyen, Canh Toan; Phung, Hoa; Dat Nguyen, Tien; Lee, Choonghan; Kim, Uikyum; Lee, Donghyouk; Moon, Hyungpil; Koo, Jachoon; Nam, Jae-do; Ryeol Choi, Hyouk

2014-06-01

A kind of dielectric elastomer (DE) material, called ‘synthetic elastomer’, has been developed based on acrylonitrile butadiene rubber (NBR) to be used as a dielectric elastomer actuator (DEA). By stacking single layers of synthetic elastomer, a linear actuator, called a multistacked actuator, is produced, and used by mechatronic and robotic systems to generate linear motion. In this paper, we demonstrate the application of the multistacked dielectric elastomer actuator in a biomimetic legged robot. A miniature robot driven by a biomimetic actuation system with four 2-DOF (two-degree-of-freedom) legged mechanisms is realized. Based on the experimental results, we evaluate the performance of the proposed robot and validate the feasibility of the multistacked actuator in a locomotion system as a replacement for conventional actuators.

A small biomimetic quadruped robot driven by multistacked dielectric elastomer actuators

International Nuclear Information System (INIS)

Nguyen, Canh Toan; Phung, Hoa; Nguyen, Tien Dat; Lee, Choonghan; Kim, Uikyum; Lee, Donghyouk; Moon, Hyungpil; Koo, Jachoon; Choi, Hyouk Ryeol; Nam, Jae-do

2014-01-01

A kind of dielectric elastomer (DE) material, called ‘synthetic elastomer’, has been developed based on acrylonitrile butadiene rubber (NBR) to be used as a dielectric elastomer actuator (DEA). By stacking single layers of synthetic elastomer, a linear actuator, called a multistacked actuator, is produced, and used by mechatronic and robotic systems to generate linear motion. In this paper, we demonstrate the application of the multistacked dielectric elastomer actuator in a biomimetic legged robot. A miniature robot driven by a biomimetic actuation system with four 2-DOF (two-degree-of-freedom) legged mechanisms is realized. Based on the experimental results, we evaluate the performance of the proposed robot and validate the feasibility of the multistacked actuator in a locomotion system as a replacement for conventional actuators. (paper)

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)

Reconfigurability of behavioural specifications for manufacturing systems

Science.gov (United States)

Schmidt, Klaus Werner

2017-12-01

Reconfigurable manufacturing systems (RMS) support flexibility in the product variety and the configuration of the manufacturing system itself in order to enable quick adjustments to new products and production requirements. As a consequence, an essential feature of RMS is their ability to rapidly modify the control strategy during run-time. In this paper, the particular problem of changing the specified operation of a RMS, whose logical behaviour is modelled as a finite state automaton, is addressed. The notion of reconfigurability of specifications (RoS) is introduced and it is shown that the stated reconfiguration problem can be formulated as a controlled language convergence problem. In addition, algorithms for the verification of RoS and the construction of a reconfiguration supervisor are proposed. The supervisor is realised in a modular way which facilitates the extension by new configurations. Finally, it is shown that a supremal nonblocking and controllable strict subautomaton of the plant automaton that fulfils RoS exists in case RoS is violated for the plant automaton itself and an algorithm for the computation of this strict subautomaton is presented. The developed concepts and results are illustrated by a manufacturing cell example.

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).

Bi-directional series-parallel elastic actuator and overlap of the actuation layers.

Science.gov (United States)

Furnémont, Raphaël; Mathijssen, Glenn; Verstraten, Tom; Lefeber, Dirk; Vanderborght, Bram

2016-01-27

Several robotics applications require high torque-to-weight ratio and energy efficient actuators. Progress in that direction was made by introducing compliant elements into the actuation. A large variety of actuators were developed such as series elastic actuators (SEAs), variable stiffness actuators and parallel elastic actuators (PEAs). SEAs can reduce the peak power while PEAs can reduce the torque requirement on the motor. Nonetheless, these actuators still cannot meet performances close to humans. To combine both advantages, the series parallel elastic actuator (SPEA) was developed. The principle is inspired from biological muscles. Muscles are composed of motor units, placed in parallel, which are variably recruited as the required effort increases. This biological principle is exploited in the SPEA, where springs (layers), placed in parallel, can be recruited one by one. This recruitment is performed by an intermittent mechanism. This paper presents the development of a SPEA using the MACCEPA principle with a self-closing mechanism. This actuator can deliver a bi-directional output torque, variable stiffness and reduced friction. The load on the motor can also be reduced, leading to a lower power consumption. The variable recruitment of the parallel springs can also be tuned in order to further decrease the consumption of the actuator for a given task. First, an explanation of the concept and a brief description of the prior work done will be given. Next, the design and the model of one of the layers will be presented. The working principle of the full actuator will then be given. At the end of this paper, experiments showing the electric consumption of the actuator will display the advantage of the SPEA over an equivalent stiff actuator.

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-...

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.

Design Flow Instantiation for Run-Time Reconfigurable Systems: A Case Study

Directory of Open Access Journals (Sweden)

Yang Qu

2007-12-01

Full Text Available Reconfigurable system is a promising alternative to deliver both flexibility and performance at the same time. New reconfigurable technologies and technology-dependent tools have been developed, but a complete overview of the whole design flow for run-time reconfigurable systems is missing. In this work, we present a design flow instantiation for such systems using a real-life application. The design flow is roughly divided into two parts: system level and implementation. At system level, our supports for hardware resource estimation and performance evaluation are applied. At implementation level, technology-dependent tools are used to realize the run-time reconfiguration. The design case is part of a WCDMA decoder on a commercially available reconfigurable platform. The results show that using run-time reconfiguration can save over 40% area when compared to a functionally equivalent fixed system and achieve 30 times speedup in processing time when compared to a functionally equivalent pure software design.

Operating System Concepts for Reconfigurable Computing: Review and Survey

Directory of Open Access Journals (Sweden)

Marcel Eckert

2016-01-01

Full Text Available One of the key future challenges for reconfigurable computing is to enable higher design productivity and a more easy way to use reconfigurable computing systems for users that are unfamiliar with the underlying concepts. One way of doing this is to provide standardization and abstraction, usually supported and enforced by an operating system. This article gives historical review and a summary on ideas and key concepts to include reconfigurable computing aspects in operating systems. The article also presents an overview on published and available operating systems targeting the area of reconfigurable computing. The purpose of this article is to identify and summarize common patterns among those systems that can be seen as de facto standard. Furthermore, open problems, not covered by these already available systems, are identified.

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).

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.

Soft buckling actuators

Energy Technology Data Exchange (ETDEWEB)

Yang, Dian; Whitesides, George M.

2017-12-26

A soft actuator is described, including: a rotation center having a center of mass; a plurality of bucklable, elastic structural components each comprising a wall defining an axis along its longest dimension, the wall connected to the rotation center in a way that the axis is offset from the center of mass in a predetermined direction; and a plurality of cells each disposed between two adjacent bucklable, elastic structural components and configured for connection with a fluid inflation or deflation source; wherein upon the deflation of the cell, the bucklable, elastic structural components are configured to buckle in the predetermined direction. A soft actuating device including a plurality of the soft actuators and methods of actuation using the soft actuator or soft actuating device disclosed herein are also described.

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)

Performance Analysis of Generating Function Approach for Optimal Reconfiguration of Formation Flying

Directory of Open Access Journals (Sweden)

Kwangwon Lee

2013-03-01

Full Text Available The use of generating functions for solving optimal rendezvous problems has an advantage in the sense that it does not require one to guess and iterate the initial costate. This paper presents how to apply generating functions to analyze spacecraft optimal reconfiguration between projected circular orbits. The series-based solution obtained by using generating functions demonstrates excellent convergence and approximation to the nonlinear reference solution obtained from a numerical shooting method. These favorable properties are expected to hold for analyzing optimal formation reconfiguration under perturbations and non-circular reference orbits.

Enhanced situation awareness and decision making for an intelligent reconfigurable reactor power controller

International Nuclear Information System (INIS)

Kenney, S.J.; Edwards, R.M.

1996-01-01

A Learning Automata based intelligent reconfigurable controller has been adapted for use as a reactor power controller to achieve improved reactor temperature performance. The intelligent reconfigurable controller is capable of enforcing either a classical or an optimal reactor power controller based on control performance feedback. Four control performance evaluation measures: dynamically estimated average quadratic temperature error, power, rod reactivity and rod reactivity rate were developed to provide feedback to the control decision component of the intelligent reconfigurable controller. Fuzzy Logic and Neural Network controllers have been studied for inclusion in the bank of controllers that form the intermediate level of an enhanced intelligent reconfigurable reactor power controller (IRRPC). The increased number of alternatives available to the supervisory level of the IRRPC requires enhanced situation awareness. Additional performance measures have been designed and a method for synthesizing them into a single indication of the overall performance of the currently enforced reactor power controller has been conceptualized. Modification of the reward/penalty scheme implemented in the existing IRRPC to increase the quality of the supervisory level decision process has been studied. The logogen model of human memory (Morton, 1969) and individual controller design information could be used to allocate reward to the most appropriate controller. Methods for allocating supervisory level attention were also studied with the goal of maximizing learning rate

Hierarchically assembled DNA origami tubules with reconfigurable chirality

International Nuclear Information System (INIS)

Chen, Haorong; Cha, Tae-Gon; Pan, Jing; Choi, Jong Hyun

2013-01-01

The dynamic reconfiguration of a hierarchically assembled tubular structure is demonstrated using the DNA origami technique. Short cylindrical DNA origami monomers are synthesized and linked into elongated tubules, which can then be disassembled via toehold-mediated strand displacement. The disassembled subunits are subsequently linked into tubules of a different chirality. The reconfiguration is performed with the subunits carrying dumbbell hairpin DNA oligonucleotides or gold nanoparticles (AuNPs). The reconfiguration of higher order origami structures presented here is useful for constructing dynamic nanostructures that exceed the size limit of single DNA origami and may facilitate the study of molecular or particle interactions by tuning their relative distance and organization. (paper)

Performance study of a hydrogen powered metal hydride actuator

International Nuclear Information System (INIS)

Bhuiya, Md Mainul Hossain; Kim, Kwang J

2016-01-01

A thermally driven hydrogen powered actuator integrating metal hydride hydrogen storage reactor, which is compact, noiseless, and able to generate smooth actuation, is presented in this article. To test the plausibility of a thermally driven actuator, a conventional piston type actuator was integrated with LaNi 5 based hydrogen storage system. Copper encapsulation followed by compaction of particles into pellets, were adopted to improve overall thermal conductivity of the reactor. The operation of the actuator was thoroughly investigated for an array of operating temperature ranges. Temperature swing of the hydride reactor triggering smooth and noiseless actuation over several operating temperature ranges were monitored for quantification of actuator efficiency. Overall, the actuator generated smooth and consistent strokes during repeated cycles of operation. The efficiency of the actuator was found to be as high as 13.36% for operating a temperature range of 20 °C–50 °C. Stress–strain characteristics, actuation hysteresis etc were studied experimentally. Comparison of stress–strain characteristics of the proposed actuator with traditional actuators, artificial muscles and so on was made. The study suggests that design modification and use of high pressure hydride may enhance the performance and broaden the application horizon of the proposed actuator in future. (paper)

Optimal energy management strategy for self-reconfigurable batteries

International Nuclear Information System (INIS)

Bouchhima, Nejmeddine; Schnierle, Marc; Schulte, Sascha; Birke, Kai Peter

2017-01-01

This paper proposes a novel energy management strategy for multi-cell high voltage batteries where the current through each cell can be controlled, called self-reconfigurable batteries. An optimized control strategy further enhances the energy efficiency gained by the hardware architecture of those batteries. Currently, achieving cell equalization by using the active balancing circuits is considered as the best way to optimize the energy efficiency of the battery pack. This study demonstrates that optimizing the energy efficiency of self-reconfigurable batteries is no more strongly correlated to the cell balancing. According to the features of this novel battery architecture, the energy management strategy is formulated as nonlinear dynamic optimization problem. To solve this optimal control, an optimization algorithm that generates the optimal discharge policy for a given driving cycle is developed based on dynamic programming and code vectorization. The simulation results show that the designed energy management strategy maximizes the system efficiency across the battery lifetime over conventional approaches. Furthermore, the present energy management strategy can be implemented online due to the reduced complexity of the optimization algorithm. - Highlights: • The energy efficiency of self-reconfigurable batteries is maximized. • The energy management strategy for the battery is formulated as optimal control problem. • Developing an optimization algorithm using dynamic programming techniques and code vectorization. • Simulation studies are conducted to validate the proposed optimal strategy.

Switchable reconfiguration of nucleic acid nanostructures by stimuli-responsive DNA machines.

Science.gov (United States)

Liu, Xiaoqing; Lu, Chun-Hua; Willner, Itamar

2014-06-17

CONSPECTUS: The base sequence in DNA dictates structural and reactivity features of the biopolymer. These properties are implemented to use DNA as a unique material for developing the area of DNA nanotechnology. The design of DNA machines represents a rapidly developing research field in the area of DNA nanotechnology. The present Account discusses the switchable reconfiguration of nucleic acid nanostructures by stimuli-responsive DNA machines, and it highlights potential applications and future perspectives of the area. Programmed switchable DNA machines driven by various fuels and antifuels, such as pH, Hg(2+) ions/cysteine, or nucleic acid strands/antistrands, are described. These include the assembly of DNA tweezers, walkers, a rotor, a pendulum, and more. Using a pH-oscillatory system, the oscillatory mechanical operation of a DNA pendulum is presented. Specifically, the synthesis and "mechanical" properties of interlocked DNA rings are described. This is exemplified with the preparation of interlocked DNA catenanes and a DNA rotaxane. The dynamic fuel-driven reconfiguration of the catenane/rotaxane structures is followed by fluorescence spectroscopy. The use of DNA machines as functional scaffolds to reconfigurate Au nanoparticle assemblies and to switch the fluorescence features within fluorophore/Au nanoparticle conjugates between quenching and surface-enhanced fluorescence states are addressed. Specifically, the fluorescence features of the different DNA machines are characterized as a function of the spatial separation between the fluorophore and Au nanoparticles. The experimental results are supported by theoretical calculations. The future development of reconfigurable stimuli-responsive DNA machines involves fundamental challenges, such as the synthesis of molecular devices exhibiting enhanced complexities, the introduction of new fuels and antifuels, and the integration of new payloads being reconfigured by the molecular devices, such as enzymes or

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

Double-Acting Sleeve Muscle Actuator for Bio-Robotic Systems

Directory of Open Access Journals (Sweden)

Hao Zheng

2013-11-01

Full Text Available This paper presents a new type of muscle-like actuator, namely double-acting (DA sleeve muscle actuator, which is suitable for the actuation of biologically-inspired and biomedical robotic systems, especially those serving human-assistance purposes (prostheses, orthoses, etc.. Developed based on the traditional pneumatic muscle actuator, the new DA sleeve muscle incorporates a unique insert at the center. With the insert occupying the central portion of the internal volume, this new actuator enjoys multiple advantages relative to the traditional pneumatic muscle, including a consistent increase of force capacity over the entire range of motion, and a significant decrease of energy consumption in operation. Furthermore, the insert encompasses an additional chamber, which generates an extension force when pressurized. As such, this new actuator provides a unique bi-directional actuation capability, and, thus, has a potential to significantly simplify the design of a muscle actuator-powered robotic system. To demonstrate this new actuator concept, a prototype has been designed and fabricated, and experiments conducted on this prototype demonstrated the enhanced force capacity and the unique bi-directional actuation capability.

Double-Acting Sleeve Muscle Actuator for Bio-Robotic Systems

Science.gov (United States)

Zheng, Hao; Shen, Xiangrong

2014-01-01

This paper presents a new type of muscle-like actuator, namely double-acting (DA) sleeve muscle actuator, which is suitable for the actuation of biologically-inspired and biomedical robotic systems, especially those serving human-assistance purposes (prostheses, orthoses, etc.). Developed based on the traditional pneumatic muscle actuator, the new DA sleeve muscle incorporates a unique insert at the center. With the insert occupying the central portion of the internal volume, this new actuator enjoys multiple advantages relative to the traditional pneumatic muscle, including a consistent increase of force capacity over the entire range of motion, and a significant decrease of energy consumption in operation. Furthermore, the insert encompasses an additional chamber, which generates an extension force when pressurized. As such, this new actuator provides a unique bi-directional actuation capability, and, thus, has a potential to significantly simplify the design of a muscle actuator-powered robotic system. To demonstrate this new actuator concept, a prototype has been designed and fabricated, and experiments conducted on this prototype demonstrated the enhanced force capacity and the unique bi-directional actuation capability. PMID:25264492

Double-Acting Sleeve Muscle Actuator for Bio-Robotic Systems.

Science.gov (United States)

Zheng, Hao; Shen, Xiangrong

2013-11-25

This paper presents a new type of muscle-like actuator, namely double-acting (DA) sleeve muscle actuator, which is suitable for the actuation of biologically-inspired and biomedical robotic systems, especially those serving human-assistance purposes (prostheses, orthoses, etc .). Developed based on the traditional pneumatic muscle actuator, the new DA sleeve muscle incorporates a unique insert at the center. With the insert occupying the central portion of the internal volume, this new actuator enjoys multiple advantages relative to the traditional pneumatic muscle, including a consistent increase of force capacity over the entire range of motion, and a significant decrease of energy consumption in operation. Furthermore, the insert encompasses an additional chamber, which generates an extension force when pressurized. As such, this new actuator provides a unique bi-directional actuation capability, and, thus, has a potential to significantly simplify the design of a muscle actuator-powered robotic system. To demonstrate this new actuator concept, a prototype has been designed and fabricated, and experiments conducted on this prototype demonstrated the enhanced force capacity and the unique bi-directional actuation capability.

A multi-electrode and pre-deformed bilayer spring structure electrostatic attractive MEMS actuator with large stroke at low actuation voltage

International Nuclear Information System (INIS)

Hu, Fangrong; Li, Zhi; Xiong, Xianming; Niu, Junhao; Peng, Zhiyong; Qian, Yixian; Yao, Jun

2012-01-01

This paper presents a multi-electrode and pre-deformed bilayer spring structure electrostatic attractive microelectromechanical systems (MEMS) actuator; it has large stroke at relatively low actuation voltage. Generally, electrostatic-attractive-force-based actuators have small stroke due to the instability resulted from the electrostatic ‘pull-in’ phenomenon. However, in many applications, the electrostatic micro-actuator with large stroke at low voltage is more preferred. By introducing a multi-electrode and a pre-deformed bilayer spring structure, an electrostatic attractive MEMS actuator with large stroke at very low actuation voltage has been successfully demonstrated in this paper. The actuator contains a central plate with a size of 300 µm × 300 µm × 1.5 µm and it is supported by four L-shaped bilayer springs which are pre-deformed due to residual stresses. Each bilayer spring is simultaneously attracted by three adjacent fixed electrodes, and the factors affecting the electrostatic attractive force are analyzed by a finite element analysis method. The prototype of the actuator is fabricated by poly-multi-user-MEMS-process (PolyMUMP) and the static performance is tested using a white light interferometer. The measured stroke of the actuator reaches 2 µm at 13 V dc, and it shows a good agreement with the simulation. (paper)

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...

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.

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.

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.

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

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.

A Design Method for Fault Reconfiguration and Fault-Tolerant Control of a Servo Motor

Directory of Open Access Journals (Sweden)

Jing He

2013-01-01

Full Text Available A design scheme that integrates fault reconfiguration and fault-tolerant position control is proposed for a nonlinear servo system with friction. Analysis of the non-linear friction torque and fault in the system is used to guide design of a sliding mode position controller. A sliding mode observer is designed to achieve fault reconfiguration based on the equivalence principle. Thus, active fault-tolerant position control of the system can be realized. A real-time simulation experiment is performed on a hardware-in-loop simulation platform. The results show that the system reconfigures well for both incipient and abrupt faults. Under the fault-tolerant control mechanism, the output signal for the system position can rapidly track given values without being influenced by faults.

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.

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

Dynamic Reconfiguration in Real-Time Systems Energy, Performance, and Thermal Perspectives

CERN Document Server

Wang, Weixun; Ranka, Sanjay

2013-01-01

Given the widespread use of real-time multitasking systems, there are tremendous optimization opportunities if reconfigurable computing can be effectively incorporated while maintaining performance and other design constraints of typical applications. The focus of this book is to describe the dynamic reconfiguration techniques that can be safely used in real-time systems. This book provides comprehensive approaches by considering synergistic effects of computation, communication as well as storage together to significantly improve overall performance, power, energy and temperature.  Provides a comprehensive introduction to optimization and dynamic reconfiguration techniques in real-time embedded systems; Covers state-of-the-art techniques and ongoing research in reconfigurable architectures; Focuses on algorithms tuned for dynamic reconfiguration techniques in real-time systems;  Provides reference for anyone designing low-power systems, energy-/temperature-constrained devices, and power-performance efficie...

Dynamic reconfiguration of human brain functional networks through neurofeedback.

Science.gov (United States)

Haller, Sven; Kopel, Rotem; Jhooti, Permi; Haas, Tanja; Scharnowski, Frank; Lovblad, Karl-Olof; Scheffler, Klaus; Van De Ville, Dimitri

2013-11-01

Recent fMRI studies demonstrated that functional connectivity is altered following cognitive tasks (e.g., learning) or due to various neurological disorders. We tested whether real-time fMRI-based neurofeedback can be a tool to voluntarily reconfigure brain network interactions. To disentangle learning-related from regulation-related effects, we first trained participants to voluntarily regulate activity in the auditory cortex (training phase) and subsequently asked participants to exert learned voluntary self-regulation in the absence of feedback (transfer phase without learning). Using independent component analysis (ICA), we found network reconfigurations (increases in functional network connectivity) during the neurofeedback training phase between the auditory target region and (1) the auditory pathway; (2) visual regions related to visual feedback processing; (3) insula related to introspection and self-regulation and (4) working memory and high-level visual attention areas related to cognitive effort. Interestingly, the auditory target region was identified as the hub of the reconfigured functional networks without a-priori assumptions. During the transfer phase, we again found specific functional connectivity reconfiguration between auditory and attention network confirming the specific effect of self-regulation on functional connectivity. Functional connectivity to working memory related networks was no longer altered consistent with the absent demand on working memory. We demonstrate that neurofeedback learning is mediated by widespread changes in functional connectivity. In contrast, applying learned self-regulation involves more limited and specific network changes in an auditory setup intended as a model for tinnitus. Hence, neurofeedback training might be used to promote recovery from neurological disorders that are linked to abnormal patterns of brain connectivity. Copyright © 2013 Elsevier Inc. All rights reserved.

Glenn Reconfigurable User-interface and Virtual reality Exploration (GURVE) Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The GRUVE (Glenn Reconfigurable User-interface and Virtual reality Exploration) Lab is a reconfigurable, large screen display facility at Nasa Glenn Research Center....

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.

Loop overhead reduction techniques for coarse grained reconfigurable architectures

NARCIS (Netherlands)

Vadivel, K.; Wijtvliet, M.; Jordans, R.; Corporaal, H.

2017-01-01

Due to their flexibility and high performance, Coarse Grained Reconfigurable Array (CGRA) are a topic of increasing research interest. However, CGRAs also have the potential to achieve very high energy efficiency in comparison to other reconfigurable architectures when hardware optimizations are

Characteristics Analysis and Testing of SMA Spring Actuator

Directory of Open Access Journals (Sweden)

Jianzuo Ma

2013-01-01

Full Text Available The biasing form two-way shape memory alloy (SMA actuator composed of SMA spring and steel spring is analyzed. Based on the force equilibrium equation, the relationship between load capacity of SMA spring and geometric parameters is established. In order to obtain the characteristics of SMA spring actuator, the output force and output displacement of SMA spring under different temperatures are analyzed by the theoretical model and the experimental method. Based on the shape memory effect of SMA, the relationship of the SMA spring actuator's output displacement with the temperature, the stress and strain, the material parameters, and the size parameters is established. The results indicate that the trend of theoretical results is basically consistent with the experimental data. The output displacement of SMA spring actuator is increased with the increasing temperature.

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....

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

Mathematical modeling of a V-stack piezoelectric aileron actuation

Directory of Open Access Journals (Sweden)

Ioan URSU

2016-12-01

Full Text Available The article presents a mathematical modeling of aileron actuation that uses piezo V-shaped stacks. The aim of the actuation is the increasing of flutter speed in the context of a control law, in order to widen the flight envelope. In this way the main advantage of such a piezo actuator, the bandwidth is exploited. The mathematical model is obtained based on free body diagrams, and the numerical simulations allow a preliminary sizing of the actuator.

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.

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.

A Reconfigurable Buck, Boost, and Buck-Boost Converter: Unified Model and Robust Controller

Directory of Open Access Journals (Sweden)

Martín Antonio Rodríguez Licea

2018-01-01

Full Text Available The need for reconfigurable, high power density, and low-cost configurations of DC-DC power electronic converters (PEC in areas such as the transport electrification and the use of renewable energy has spread out the requirement to incorporate in a single circuit several topologies, which generally result in an increment of complexity about the modeling, control, and stability analyses. In this paper, a reconfigurable topology is presented which can be applied in alterative/changing power conversion scenarios and consists of a reconfigurable Buck, Boost, and Buck-Boost DC-DC converter (RBBC. A unified averaged model of the RBBC is obtained, a robust controller is designed through a polytopic representation, and a Lyapunov based switched stability analysis of the closed-loop system is presented. The reported RBBC provides a wide range of voltage operation, theoretically from -∞ to ∞ volts with a single power source. Robust stability, even under arbitrarily fast (bounded parameter variations and reconfiguration changes, is reported including numerical and experimental results. The main advantages of the converter and the robust controller proposed are simple design, robustness against abrupt changes in the parameters, and low cost.

Electrically controllable twisted-coiled artificial muscle actuators using surface-modified polyester fibers

Science.gov (United States)

Park, Jungwoo; Yoo, Ji Wang; Seo, Hee Won; Lee, Youngkwan; Suhr, Jonghwan; Moon, Hyungpil; Koo, Ja Choon; Ryeol Choi, Hyouk; Hunt, Robert; Kim, Kwang Jin; Kim, Soo Hyun; Nam, Jae-Do

2017-03-01

As a new class of thermally activated actuators based on polymeric fibers, we investigated polyethylene terephthalate (PET) yarns for the development of a twisted-coiled polymer fiber actuator (TCA). The PET yarn TCA exhibited the maximum linear actuation up to 8.9% by external heating at above the glass transition temperature, 160 °C-180 °C. The payload of the actuator was successfully correlated with the preload and training-load conditions by an empirical equation. Furthermore, the PET-based TCA was electrically driven by Joule heating after the PET surface was metallization with silver. For the fast and precise control of PET yarn TCA, electroless silver plating was conducted to form electrical conductive layers on the PET fiber surface. The silver plated PET-based TCA was tested by Joule heating and the tensile actuation was increased up to 12.1% (6 V) due to the enhanced surface hardness and slippage of PET fibers. Overall, silver plating of the polymeric yarn provided a fast actuation speed and enhanced actuation performance of the TCA actuator by Joule heating, providing a great potential for being used in artificial muscle for biomimetic machines including robots, industrial actuators and powered exoskeletons.

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)

A wireless actuating drug delivery system

International Nuclear Information System (INIS)

Jo, Won-Jun; Baek, Seung-Ki; Park, Jung-Hwan

2015-01-01

A wireless actuating drug delivery system was devised. The system is based on induction heating for drug delivery. In this study, thermally generated nitrogen gas produced by induction heating of azobisisobutyronitrile (AIBN) was utilized for pressure-driven release of the drug. The delivery device consists of an actuator chamber, a drug reservoir, and a microchannel. A semicircular copper disc (5 and 6 mm in diameter and 100 µm thick), and thermal conductive tape were integrated as the heating element in the actuator chamber. The final device was 2.7 mm thick. 28 µl of drug solution were placed in the reservoir and the device released the drug quickly at the rate of 6 µl s −1 by induction heating at 160 µT of magnetic intensity. The entire drug solution was released and dispersed after subcutaneous implantation under identical experimental condition. This study demonstrates that the device was simply prepared and drug delivery could be achieved by wireless actuation of a thin, pressure-driven actuator. (paper)

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.

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.

Sealing-free fast-response paraffin/nanoporous gold hybrid actuator

Science.gov (United States)

Ye, Xing-Long; Jin, Hai-Jun

2017-09-01

Paraffin-based actuators can deliver large actuation strokes and high actuation stress, but often suffer from a low response rate and leaking problems. Here, we report a new paraffin/metal hybrid actuator, which was fabricated by infiltrating nanoporous gold with paraffin. It exhibits a fast actuation rate owing to the high thermal conductivity of the inter-connected metal phase, and requires no external sealing because liquid paraffin can be well confined in nanoscale channels, due to the large capillarity. We found that in this hybrid actuator, the stress generated by actuation is negligibly small when the characteristic size of the nanoporous gold (L) is above ˜70 nm, and increases dramatically with a decreasing size when L paraffin wax—the paraffin in smaller pores can sustain larger tensile stress, and thus the contraction of paraffin during cooling can be translated into larger compression stress and strain energy in a metal framework, leading to a larger actuation stress and energy. We also demonstrate that complex actuation motions can be achieved by incorporating hierarchical-structured nanoporous metal with paraffin.

HoneyComb: An Application-Driven Online Adaptive Reconfigurable Hardware Architecture

Directory of Open Access Journals (Sweden)

Alexander Thomas

2012-01-01

Full Text Available Since the introduction of the first reconfigurable devices in 1985 the field of reconfigurable computing developed a broad variety of architectures from fine-grained to coarse-grained types. However, the main disadvantages of the reconfigurable approaches, the costs in area, and power consumption, are still present. This contribution presents a solution for application-driven adaptation of our reconfigurable architecture at register transfer level (RTL to reduce the resource requirements and power consumption while keeping the flexibility and performance for a predefined set of applications. Furthermore, implemented runtime adaptive features like online routing and configuration sequencing will be presented and discussed. A presentation of the prototype chip of this architecture designed in 90 nm standard cell technology manufactured by TSMC will conclude this contribution.

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

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.

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)

Proof of Concept of an Irradiance Estimation System for Reconfigurable Photovoltaic Arrays

Directory of Open Access Journals (Sweden)

Vincenzo Li Vigni

2015-06-01

Full Text Available In order to reduce the mismatch effect caused by non-uniform shadows in PV arrays, reconfigurable interconnections approaches have been recently proposed in the literature. These systems usually require the knowledge of the solar radiation affecting every solar module. The aim of this work is to evaluate the effectiveness of three irradiance estimation approaches in order to define which can be well suited for reconfigurable PV arrays. It is presented a real-time solar irradiance estimation device (IrradEst, implementing the three different estimation methods. The proposed system is based on mathematical models of PV modules enabling to estimate irradiation values by sensing a combination of temperature, voltage and current of a PV module. Experimental results showed generally good agreement between the estimated irradiances and the measurements performed by a standard pyranometer taken as reference. Finally one of the three methods was selected as possible solution for a reconfigurable PV system.

Reconfigurable Computing As an Enabling Technology for Single-Photon-Counting Laser Altimetry

Science.gov (United States)

Powell, Wesley; Hicks, Edward; Pinchinat, Maxime; Dabney, Philip; McGarry, Jan; Murray, Paul

2003-01-01

Single-photon-counting laser altimetry is a new measurement technique offering significant advantages in vertical resolution, reducing instrument size, mass, and power, and reducing laser complexity as compared to analog or threshold detection laser altimetry techniques. However, these improvements come at the cost of a dramatically increased requirement for onboard real-time data processing. Reconfigurable computing has been shown to offer considerable performance advantages in performing this processing. These advantages have been demonstrated on the Multi-KiloHertz Micro-Laser Altimeter (MMLA), an aircraft based single-photon-counting laser altimeter developed by NASA Goddard Space Flight Center with several potential spaceflight applications. This paper describes how reconfigurable computing technology was employed to perform MMLA data processing in real-time under realistic operating constraints, along with the results observed. This paper also expands on these prior results to identify concepts for using reconfigurable computing to enable spaceflight single-photon-counting laser altimeter instruments.

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.

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.

Optically controlled reconfigurable antenna for 5G future broadband cellular communication networks

DEFF Research Database (Denmark)

Costa, I.F. da; Spadoti, D. H.; Cerqueira Sodre Jr., Arismar

2017-01-01

This paper presents an optically controlled reconfigurable antenna for millimetre-wave frequency range. Silicon switches are used to control the optical reconfiguration, modifying the frequency response and radiation pattern of the antenna design. Therefore, the system can switch between the ligh......This paper presents an optically controlled reconfigurable antenna for millimetre-wave frequency range. Silicon switches are used to control the optical reconfiguration, modifying the frequency response and radiation pattern of the antenna design. Therefore, the system can switch between...

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).

Reconfigurable antennas radiations using plasma Faraday cage

OpenAIRE

Barro , Oumar Alassane; Himdi , Mohamed; Lafond , Olivier

2015-01-01

International audience; This letter presents a new reconfigurable plasma antenna associated with a Faraday cage. The Faraday cage is realized using a fluorescent lamp. A patch antenna with a broadside radiation pattern or a monopole antenna with an end-fire radiation pattern , operating at 2.45 GHz, is placed inside Faraday cage. The performance of the reconfigurable system is observed in terms of input reflection coefficient, gain and radiation pattern via simulation and measurement. It is s...

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:...

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.

Dielectric elastomer actuators for octopus inspired suction cups.

Science.gov (United States)

Follador, M; Tramacere, F; Mazzolai, B

2014-09-25

Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms.

Dielectric elastomer actuators for octopus inspired suction cups

International Nuclear Information System (INIS)

Follador, M; Tramacere, F; Mazzolai, B

2014-01-01

Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms. (paper)

Robust, Flexible and Lightweight Dielectric Barrier Discharge Actuators Using Nanofoams/Aerogels