Adaptive Sliding Mode Control for Hydraulic Drives
Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.;
2013-01-01
This paper presents a new adaptive sliding mode controller generally applicable for position tracking control of electro-hydraulic valve-cylinder drives (VCD’s). The proposed control scheme requires limited knowledge on system parameters, and employs only piston- and valve spool position feedback...
Adaptive sliding mode control for a class of chaotic systems
Farid, R.; Ibrahim, A.; Zalam, B., E-mail: ramy5475@yahoo.com [Menofia University, Faculty of Electronic Engineering, Department of Industrial Electronics and Control, Menuf, Menofia (Egypt)
2015-03-30
Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller.
Adaptive sliding mode control for a class of chaotic systems
Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller
Robust observer-based adaptive fuzzy sliding mode controller
Oveisi, Atta; Nestorović, Tamara
2016-08-01
In this paper, a new observer-based adaptive fuzzy integral sliding mode controller is proposed based on the Lyapunov stability theorem. The plant is subjected to a square-integrable disturbance and is assumed to have mismatch uncertainties both in state- and input-matrices. Based on the classical sliding mode controller, the equivalent control effort is obtained to satisfy the sufficient requirement of sliding mode controller and then the control law is modified to guarantee the reachability of the system trajectory to the sliding manifold. In order to relax the norm-bounded constrains on the control law and solve the chattering problem of sliding mode controller, a fuzzy logic inference mechanism is combined with the controller. An adaptive law is then introduced to tune the parameters of the fuzzy system on-line. Finally, for evaluating the controller and the robust performance of the closed-loop system, the proposed regulator is implemented on a real-time mechanical vibrating system.
Sliding mode control of wind-induced vibrations using fuzzy sliding surface and gain adaptation
Thenozhi, Suresh; Yu, Wen
2016-04-01
Although fuzzy/adaptive sliding mode control can reduce the chattering problem in structural vibration control applications, they require the equivalent control and the upper bounds of the system uncertainties. In this paper, we used fuzzy logic to approximate the standard sliding surface and designed a dead-zone adaptive law for tuning the switching gain of the sliding mode control. The stability of the proposed controller is established using Lyapunov stability theory. A six-storey building prototype equipped with an active mass damper has been used to demonstrate the effectiveness of the proposed controller towards the wind-induced vibrations.
Adaptive Fractional Fuzzy Sliding Mode Control for Multivariable Nonlinear Systems
Junhai Luo
2014-01-01
Full Text Available This paper presents a robust adaptive fuzzy sliding mode control method for a class of uncertain nonlinear systems. The fractional order calculus is employed in the parameter updating stage. The underlying stability analysis as well as parameter update law design is carried out by Lyapunov based technique. In the simulation, two examples including a comparison with the traditional integer order counterpart are given to show the effectiveness of the proposed method. The main contribution of this paper consists in the control performance is better for the fractional order updating law than that of traditional integer order.
L1 adaptive control with sliding-mode based adaptive law
Jie LUO; Chengyu CAO
2015-01-01
This paper presents an adaptive control scheme with an integration of sliding mode control into the L1 adaptive control architecture, which provides good tracking performance as well as robustness against matched uncertainties. Sliding mode control is used as an adaptive law in the L1 adaptive control architecture, which is considered as a virtual control of error dynamics between estimated states and real states. Low-pass filtering mechanism in the control law design prevents a discontinuous signal in the adaptive law from appearing in actual control signal while maintaining control accuracy. By using sliding mode control as a virtual control of error dynamics and introducing the low-pass filtered control signal, the chattering effect is eliminated. The performance bounds between the close-loop adaptive system and the closed-loop reference system are characterized in this paper. Numerical simulation is provided to demonstrate the performance of the presented adaptive control scheme.
Adaptive Global Sliding Mode Control for MEMS Gyroscope Using RBF Neural Network
Yundi Chu
2015-01-01
Full Text Available An adaptive global sliding mode control (AGSMC using RBF neural network (RBFNN is proposed for the system identification and tracking control of micro-electro-mechanical system (MEMS gyroscope. Firstly, a new kind of adaptive identification method based on the global sliding mode controller is designed to update and estimate angular velocity and other system parameters of MEMS gyroscope online. Moreover, the output of adaptive neural network control is used to adjust the switch gain of sliding mode control dynamically to approach the upper bound of unknown disturbances. In this way, the switch item of sliding mode control can be converted to the output of continuous neural network which can weaken the chattering in the sliding mode control in contrast to the conventional fixed gain sliding mode control. Simulation results show that the designed control system can get satisfactory tracking performance and effective estimation of unknown parameters of MEMS gyroscope.
Chattering-free fuzzy adaptive robust sliding-mode vibration control of a smart flexible beam
Chattering is an undesired phenomenon associated with classical sliding-mode control. The discontinuous bang–bang robust controller causes chattering near the equilibrium. To attenuate the chattering, in this paper, a fuzzy logic smooth switch system is integrated with the adaptive robust sliding-mode control to form a fuzzy adaptive robust sliding-mode control for the active vibration control of a smart flexible beam integrated with piezoceramic actuators and sensors. The asymptotical stability proof of the proposed fuzzy adaptive robust sliding-mode controller is provided by Lyapunov's direct method. The experimental results show that the proposed fuzzy adaptive robust sliding-mode controller quickly suppresses the vibration. Additionally, with the fuzzy switch system, the chattering is successfully attenuated
Backstepping design of missile guidance and control based on adaptive fuzzy sliding mode control
Ran Maopeng; Wang Qing; Hou Delong; Dong Chaoyang
2014-01-01
This paper presents an integrated missile guidance and control law based on adaptive fuzzy sliding mode control. The integrated model is formulated as a block-strict-feedback nonlinear system, in which modeling errors, unmodeled nonlinearities, target maneuvers, etc. are viewed as unknown uncertainties. The adaptive nonlinear control law is designed based on backstepping and sliding mode control techniques. An adaptive fuzzy system is adopted to approximate the coupling nonlinear functions of...
Tat-Bao-Thien Nguyen
2014-01-01
Full Text Available In this paper, based on fuzzy neural networks, we develop an adaptive sliding mode controller for chaos suppression and tracking control in a chaotic permanent magnet synchronous motor (PMSM drive system. The proposed controller consists of two parts. The first is an adaptive sliding mode controller which employs a fuzzy neural network to estimate the unknown nonlinear models for constructing the sliding mode controller. The second is a compensational controller which adaptively compensates estimation errors. For stability analysis, the Lyapunov synthesis approach is used to ensure the stability of controlled systems. Finally, simulation results are provided to verify the validity and superiority of the proposed method.
Synchronization of a modified Chua's circuit system via adaptive sliding mode control
This study addresses the adaptive synchronization of a modified Chua's circuit system with both unknown system parameters and the nonlinearity in the control input. An adaptive switching surface is newly adopted such that it becomes easy to ensure the stability of the error dynamics in the sliding mode. Based on this adaptive switching surface, an adaptive sliding mode controller (ASMC) is derived to guarantee the occurrence of the sliding motion, even when the system is undergoing input nonlinearity. This method can also be easily extended to a general class of Chua's circuits. An illustrative example is given to show the applicability of the proposed ASMC design
Robust synchronization of drive-response chaotic systems via adaptive sliding mode control
A robust adaptive sliding control scheme is developed in this study to achieve synchronization for two identical chaotic systems in the presence of uncertain system parameters, external disturbances and nonlinear control inputs. An adaptation algorithm is given based on the Lyapunov stability theory. Using this adaptation technique to estimate the upper-bounds of parameter variation and external disturbance uncertainties, an adaptive sliding mode controller is then constructed without requiring the bounds of parameter and disturbance uncertainties to be known in advance. It is proven that the proposed adaptive sliding mode controller can maintain the existence of sliding mode in finite time in uncertain chaotic systems. Finally, numerical simulations are presented to show the effectiveness of the proposed control scheme.
Constant Power Control of a Proton Exchange Membrane Fuel Cell through Adaptive Fuzzy Sliding Mode
Minxiu Yan
2013-05-01
Full Text Available Fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. The paper describes a mathematical model of proton exchange membrane fuel cells by analyzing the working mechanism of the proton exchange membrane fuel cell. Furthermore, an adaptive fuzzy sliding mode controller is designed for the constant power output of PEMFC system. Simulation results prove that adaptive fuzzy sliding mode control has better control effect than conventional fuzzy sliding mode control.
Anti-Synchronization of Chaotic Systems via Adaptive Sliding Mode Control
An anti-synchronization scheme is proposed to achieve the anti-synchronization behavior between chaotic systems with fully unknown parameters. A sliding surface and an adaptive sliding mode controller are designed to gain the anti-synchronization. The stability of the error dynamics is proven theoretically using the Lyapunov stability theory. Finally numerical results are presented to justify the theoretical analysis
Backstepping design of missile guidance and control based on adaptive fuzzy sliding mode control
Ran Maopeng
2014-06-01
Full Text Available This paper presents an integrated missile guidance and control law based on adaptive fuzzy sliding mode control. The integrated model is formulated as a block-strict-feedback nonlinear system, in which modeling errors, unmodeled nonlinearities, target maneuvers, etc. are viewed as unknown uncertainties. The adaptive nonlinear control law is designed based on backstepping and sliding mode control techniques. An adaptive fuzzy system is adopted to approximate the coupling nonlinear functions of the system, and for the uncertainties, we utilize an online-adaptive control law to estimate the unknown parameters. The stability analysis of the closed-loop system is also conducted. Simulation results show that, with the application of the adaptive fuzzy sliding mode control, small miss distances and smooth missile trajectories are achieved, and the system is robust against system uncertainties and external disturbances.
Backstepping design of missile guidance and control based on adaptive fuzzy sliding mode control
Ran Maopeng; Wang Qing; Hou Delong; Dong Chaoyang
2014-01-01
This paper presents an integrated missile guidance and control law based on adaptive fuzzy sliding mode control. The integrated model is formulated as a block-strict-feedback nonlinear system, in which modeling errors, unmodeled nonlinearities, target maneuvers, etc. are viewed as unknown uncertainties. The adaptive nonlinear control law is designed based on backstepping and sliding mode control techniques. An adaptive fuzzy system is adopted to approximate the coupling nonlinear functions of the system, and for the uncertainties, we utilize an online-adaptive control law to estimate the unknown parameters. The stability analysis of the closed-loop system is also conducted. Simulation results show that, with the application of the adaptive fuzzy sliding mode control, small miss distances and smooth missile trajectories are achieved, and the system is robust against system uncertainties and external disturbances.
Mohammad Jannati
2014-05-01
Full Text Available This paper presents a technique for speed sensorless Rotor Flux Oriented Control (RFOC of 3-phase Induction Motor (IM under open-phase fault (unbalanced or faulty IM. The presented RFOC strategy is based on rotational transformation. An adaptive sliding mode control system with an adaptive switching gain is proposed instead of the speed PI controller. Using an adaptive sliding mode control causes the proposed speed sensorless RFOC drive system to become insensitive to uncertainties such as load disturbances and parameter variations. Moreover, with adaptation of the sliding switching gain, calculation of the system uncertainties upper bound is not needed. Finally, simulation results have been presented to confirm the good performance of the proposed method.
Farzin Piltan, N. Sulaiman, Payman Ferdosali, Mehdi Rashidi, Zahra Tajpeikar
2011-12-01
Full Text Available This research is focused on proposed adaptive fuzzy sliding mode algorithms with the adaptation lawsderived in the Lyapunov sense. The stability of the closed-loop system is proved mathematically based onthe Lyapunov method. Adaptive MIMO fuzzy compensate fuzzy sliding mode method design a MIMO fuzzysystem to compensate for the model uncertainties of the system, and chattering also solved by linearsaturation method. Since there is no tuning method to adjust the premise part of fuzzy rules so wepresented a scheme to online tune consequence part of fuzzy rules. Classical sliding mode control isrobust to control model uncertainties and external disturbances. A sliding mode method with a switchingcontrol low guarantees the stability of the certain and/or uncertain system, but the addition of the switchingcontrol low introduces chattering into the system. One way to reduce or eliminate chattering is to insert aboundary layer method inside of a boundary layer around the sliding surface. Classical sliding modecontrol method has difficulty in handling unstructured model uncertainties. One can overcome this problemby combining a sliding mode controller and artificial intelligence (e.g. fuzzy logic. To approximate a timevaryingnonlinear dynamic system, a fuzzy system requires a large amount of fuzzy rule base. This largenumber of fuzzy rules will cause a high computation load. The addition of an adaptive law to a fuzzy slidingmode controller to online tune the parameters of the fuzzy rules in use will ensure a moderatecomputational load. The adaptive laws in this algorithm are designed based on the Lyapunov stabilitytheorem. Asymptotic stability of the closed loop system is also proved in the sense of Lyapunov.
Adaptive robust PID controller design based on a sliding mode for uncertain chaotic systems
A robust adaptive PID controller design motivated from the sliding mode control is proposed for a class of uncertain chaotic systems in this paper. Three PID control gains, K p, K i, and K d, are adjustable parameters and will be updated online with an adequate adaptation mechanism to minimize a previously designed sliding condition. By introducing a supervisory controller, the stability of the closed-loop PID control system under with the plant uncertainty and external disturbance can be guaranteed. Finally, a well-known Duffing-Holmes chaotic system is used as an illustrative to show the effectiveness of the proposed robust adaptive PID controller
Model-Free Adaptive Fuzzy Sliding Mode Controller Optimized by Particle Swarm for Robot Manipulator
Amin Jalali
2013-05-01
Full Text Available The main purpose of this paper is to design a suitable control scheme that confronts the uncertainties in a robot. Sliding mode controller (SMC is one of the most important and powerful nonlinear robust controllers which has been applied to many non-linear systems. However, this controller has some intrinsic drawbacks, namely, the chattering phenomenon, equivalent dynamic formulation, and sensitivity to the noise. This paper focuses on applying artificial intelligence integrated with the sliding mode control theory. Proposed adaptive fuzzy sliding mode controller optimized by Particle swarm algorithm (AFSMC-PSO is a Mamdani’s error based fuzzy logic controller (FLS with 7 rules integrated with sliding mode framework to provide the adaptation in order to eliminate the high frequency oscillation (chattering and adjust the linear sliding surface slope in presence of many different disturbances and the best coefficients for the sliding surface were found by offline tuning Particle Swarm Optimization (PSO. Utilizing another fuzzy logic controller as an impressive manner to replace it with the equivalent dynamic part is the main goal to make the model free controller which compensate the unknown system dynamics parameters and obtain the desired control performance without exact information about the mathematical formulation of model.
Faten Baklouti
2016-01-01
Full Text Available The trajectory tracking of underactuated nonlinear system with two degrees of freedom is tackled by an adaptive fuzzy hierarchical sliding mode controller. The proposed control law solves the problem of coupling using a hierarchical structure of the sliding surfaces and chattering by adopting different reaching laws. The unknown system functions are approximated by fuzzy logic systems and free parameters can be updated online by adaptive laws based on Lyapunov theory. Two comparative studies are made in this paper. The first comparison is between three different expressions of reaching laws to compare their abilities to reduce the chattering phenomenon. The second comparison is made between the proposed adaptive fuzzy hierarchical sliding mode controller and two other control laws which keep the coupling in the underactuated system. The tracking performances of each control law are evaluated. Simulation examples including different amplitudes of external disturbances are made.
Adaptive Sliding Mode BTT Autopilot for Cruise Missiles with Variable-Swept Wings
Wei-Ming Li; Rui-Sheng Sun; Hong-Yang Bai; Peng-Yun Liu
2014-01-01
In this paper, an adaptive sliding mode method was proposed for BTT autopilot of cruise missiles with variable-swept wings. To realize the whole state feedback, the roll angle, normal overloads and angular rates were considered as state variables of the autopilot, and a parametric sliding mode controller was designed via feedback linearization. A novel parametric adaptation law was put forward to estimate the nonlinear time-varying parameter perturbations in real time based on Lyapunov stability theory. A sliding mode boundary layer theory was adopted to smooth the discontinuity of control variables and eliminate the control chattering. The simulation was presented for the roll angle and overload commands tracking in different configuration schemes. The results indicated that the controlled system has robust dynamic tracking performance in condition of the large-scale aerodynamic parametric variety resulted from variable-swept wings.
Wu, Zhenhui; Dong, Chaoyang
2006-11-01
Because of nonlinearity and strong coupling of reaction-jet and aerodynamics compound control missile, a missile autopilot design method based on adaptive fuzzy sliding mode control (AFSMC) is proposed in this paper. The universal approximation ability of adaptive fuzzy system is used to approximate the nonlinear function in missile dynamics equation during the flight of high angle of attack. And because the sliding mode control is robustness to external disturbance strongly, the sliding mode surface of the error system is constructed to overcome the influence of approximation error and external disturbance so that the actual overload can track the maneuvering command with high precision. Simulation results show that the missile autopilot designed in this paper not only can track large overload command with higher precision than traditional method, but also is robust to model uncertainty and external disturbance strongly.
Cong, Shuang; Liang, Yanyang; Shang, Weiwei
2009-01-01
In this chapter, two sliding mode adaptive control strategies have been proposed for SISO and SIMO systems with unknown bound time-varying uncertainty respectively. Firstly, for a typical SISO system of position tracking in DC motor with unknown bound time-varying dead
Xuxi Zhang
2014-01-01
Full Text Available The attitude tracking problem of spacecraft in the presence of unknown disturbance is investigated. By using the adaptive control technique and the Lyapunov stability theory, a chattering-free adaptive sliding mode control law is proposed for the attitude tracking problem of spacecraft with unknown disturbance. Simulation results are employed to demonstrate the effectiveness of the proposed control design technique in this paper.
Xiuchun Li
2013-01-01
Full Text Available When the parameters of both drive and response systems are all unknown, an adaptive sliding mode controller, strongly robust to exotic perturbations, is designed for realizing generalized function projective synchronization. Sliding mode surface is given and the controlled system is asymptotically stable on this surface with the passage of time. Based on the adaptation laws and Lyapunov stability theory, an adaptive sliding controller is designed to ensure the occurrence of the sliding motion. Finally, numerical simulations are presented to verify the effectiveness and robustness of the proposed method even when both drive and response systems are perturbed with external disturbances.
An adaptive fuzzy sliding mode strategy is developed for the generalized projective synchronization of a fractional-order chaotic system, where the slave system is not necessarily known in advance. Based on the designed adaptive update laws and the linear feedback method, the adaptive fuzzy sliding controllers are proposed via the fuzzy design, and the strength of the designed controllers can be adaptively adjusted according to the external disturbances. Based on the Lyapunov stability theorem, the stability and the robustness of the controlled system are proved theoretically. Numerical simulations further support the theoretical results of the paper and demonstrate the efficiency of the proposed method. Moreover, it is revealed that the proposed method allows us to manipulate arbitrarily the response dynamics of the slave system by adjusting the desired scaling factor λi and the desired translating factor ηi, which may be used in a channel-independent chaotic secure communication. (general)
Adaptive terminal sliding mode control for high-order nonlinear dynamic systems
庄开宇; 苏宏业; 张克勤; 褚健
2003-01-01
An adaptive terminal sliding mode control (SMC) technique is proposed to deal with the tracking problem for a class of high-order nonlinear dynamic systems. It is shown that a function augmented sliding hyperplane can be used to develop a new terminal sliding mode for high-order nonlinear systems. A terminal SMC controller based on Lyapunov theory is designed to force the state variables of the closed-loop system to reach and remain on the terminal sliding mode, so that the output tracking error then converges to zero in finite time which can be set arbitrarily. An adaptive mechanism is introduced to estimate the unknown parameters of the upper bounds of system uncertainties. The estimates are then used as controller parameters so that the effects of uncertain dynamics can be eliminated. It is also shown that the stability of the closed-loop system can be guaranteed with the proposed control strategy. The simulation of a numerical example is provided to show the effectiveness of the new method.
Adaptive Sliding Mode Robust Control for Virtual Compound-Axis Servo System
Yan Ren; Zhenghua Liu; Le Chang; Nuan Wen
2013-01-01
A structure mode of virtual compound-axis servo system is proposed to improve the tracking accuracy of the ordinary optoelectric tracking platform. It is based on the structure and principles of compound-axis servo system. A hybrid position control scheme combining the PD controller and feed-forward controller is used in subsystem to track the tracking error of the main system. This paper analyzes the influences of the equivalent disturbance in main system and proposes an adaptive sliding mod...
Adaptive Sliding Mode Robust Control for Virtual Compound-Axis Servo System
Yan Ren
2013-01-01
Full Text Available A structure mode of virtual compound-axis servo system is proposed to improve the tracking accuracy of the ordinary optoelectric tracking platform. It is based on the structure and principles of compound-axis servo system. A hybrid position control scheme combining the PD controller and feed-forward controller is used in subsystem to track the tracking error of the main system. This paper analyzes the influences of the equivalent disturbance in main system and proposes an adaptive sliding mode robust control method based on the improved disturbance observer. The sliding mode technique helps this disturbance observer to deal with the uncompensated disturbance in high frequency by making use of the rapid switching control value, which is based on the subtle error of disturbance estimation. Besides, the high-frequency chattering is alleviated effectively in this proposal. The effectiveness of the proposal is confirmed by experiments on optoelectric tracking platform.
郭亚军; 马大为; 王晓峰; 乐贵高
2011-01-01
An adaptive backstepping sliding mode control approach is introduced to control the pitch motion of a rocket launcher. Its control law is proposed to guarantee that the control system is ultimately bounded in a Lyapunov sense and make the servo system track the instruction of reference position globally and asymptotically. In addition, the sliding mode control can restrain the effects of parameter uncertainties and external disturbance. The functions of adaptive mechanism and sliding mode control are analyzed through the simulation in the different conditions. The simulation results illustrate that the method is applicable and robust.
Composite Adaptive Sliding Mode Control for Electrical Servo System using Multiple Models
Lipeng Wang
2011-01-01
Full Text Available In this study, a composite adaptive sliding mode control using Multiple Models (MM-CASMC is proposed for precision position control of an induction motor servo system with parametric uncertainties and external disturbance. The MM-CASMC is designed based on a classical sliding mode control frame. Robustness against parametric uncertainties and high-frequency extern disturbance are both obtained via online parameters estimation and switching control, respectively. A composite adaption law which combines direct and BGF-LS type indirect adaptive methods is developed to achieve both Globally Uniformly Ultimately Boundness (GUUB and approximately exponential convergence in large range under persistent excitation, the later implies clearer transient behaviour which is of great importance but not provided by standard direct adaptive method. Moreover, a multiple model adaptive control design is further incorporated to achieve improvement in transient response by utilizing model switching and parameters estimates resetting and an noval method by means of dual-channel filtering is proposed for regessor filtering and model switching. For the proposed strategy, the GUUB stability and improvments in transient behaviour and adaptability to sudden changes in the parameter values are all proved in Lyapunov sense. Simulation results verify that an induction motor servo system with the adoption of MM-CASMC can achieve favorable tracking performance and transient response in the presence of parameter variations and external load disturbance.
Adaptive PI-Based Sliding Mode Control for Nanopositioning of Piezoelectric Actuators
Jin Li
2014-01-01
Full Text Available This paper proposes an adaptive proportion-integral (PI-based sliding mode control design (APISMC used for nanopositioning of piezoelectric actuators (PEAs. Nonlinearities, mainly hysteresis, can drastically degrade the system performance. As well as the model imperfection, hysteresis can be treated as uncertainties of the system. These uncertainties can be addressed by sliding mode control (SMC since SMC is promising for positioning and tracking control. To further improve the response speed, suppress chattering, and reduce the steady-state error, the adaptive PI-based SMC is employed to replace the discontinuous control. Actually, the adaptive PI-based SMC offers a fast convergence of the sliding surface. Further, another advantage of the proposed controller lies in that its implementation only requires the online tuning PI parameters without acquiring the knowledge of bounds on system uncertainties. A linear second-order system is utilized as the estimated model to compensate for the process nonlinearity and estimate the control gain. The robust stability of the APISMC is proved through a Lyapunov stability analysis. Simulation results demonstrate that the modified SMC is superior to the original one for both positioning and tracking applications. Compared with the original, the proposed controller provides better performance—less chattering, faster response, and higher precision.
Adaptive sliding mode observer for induction motor using two-time-scale approach
Mezouar, A.; Fellah, M.K.; Hadjeri, S. [Intelligent Control and Electrical Power Systems Laboratory, Department of Electrical Engineering, Faculty of Sciences Engineering, Djillali Liabes University (22 000) Sidi Bel Abbes (Algeria)
2007-04-15
This paper presents an original method for the design of a robust adaptive sliding mode current and flux observer for induction motor drive using two-time-scale approach. This approach, based on the singular perturbation theory, decomposes the original system of the observer error dynamics into separate slow and fast subsystems of lower dimensions and permits a simple design and sequential determination of the observer gains. For the proposed observer, the rotor speed signal is assumed to be available. The stator currents and rotor flux are observed on the stationary reference frame using sliding mode concept, and the adaptive rotor time-constant is derived from Lyapunov stability theory using measured and estimated currents and estimated rotor flux. The control algorithm is based on the indirect field-oriented sliding mode control to keep the machine field oriented. The control-observer scheme seeks to provide asymptotic tracking of speed and rotor flux in spite of the presence of an uncertain load torque and unknown value of the rotor resistance. The effectiveness of this control algorithm has been successfully verified through computer simulations. (author)
Three-dimensional guidance law based on adaptive integral sliding mode control
Song Junhong; Song Shenmin
2016-01-01
For the terminal guidance problem of missiles intercepting maneuvering targets in the three-dimensional space, the design of guidance laws for non-decoupling three-dimensional engage-ment geometry is studied. Firstly, by introducing a finite time integral sliding mode manifold, a novel guidance law based on the integral sliding mode control is presented with the target acceler-ation as a known bounded external disturbance. Then, an improved adaptive guidance law based on the integral sliding mode control without the information of the upper bound on the target accel-eration is developed, where the upper bound of the target acceleration is estimated online by a designed adaptive law. The both presented guidance laws can make sure that the elevation angular rate of the line-of-sight and the azimuth angular rate of the line-of-sight converge to zero in finite time. In the end, the results of the guidance performance for the proposed guidance laws are pre-sented by numerical simulations. Although the designed guidance laws are developed for the con-stant speed missiles, the simulation results for the time-varying speed missiles are also shown to further confirm the designed guidance laws.
Three-dimensional guidance law based on adaptive integral sliding mode control
Song Junhong
2016-02-01
Full Text Available For the terminal guidance problem of missiles intercepting maneuvering targets in the three-dimensional space, the design of guidance laws for non-decoupling three-dimensional engagement geometry is studied. Firstly, by introducing a finite time integral sliding mode manifold, a novel guidance law based on the integral sliding mode control is presented with the target acceleration as a known bounded external disturbance. Then, an improved adaptive guidance law based on the integral sliding mode control without the information of the upper bound on the target acceleration is developed, where the upper bound of the target acceleration is estimated online by a designed adaptive law. The both presented guidance laws can make sure that the elevation angular rate of the line-of-sight and the azimuth angular rate of the line-of-sight converge to zero in finite time. In the end, the results of the guidance performance for the proposed guidance laws are presented by numerical simulations. Although the designed guidance laws are developed for the constant speed missiles, the simulation results for the time-varying speed missiles are also shown to further confirm the designed guidance laws.
Adaptive Terminal Sliding Mode NDO-Based Control of Underactuated AUV in Vertical Plane
Wei Chen
2016-01-01
Full Text Available The depth tracking issue of underactuated autonomous underwater vehicle (AUV in vertical plane is addressed in this paper. Considering the complicated dynamics and kinematics model for underactuated AUV, a more simplified model is obtained based on assumptions. Then a nonlinear disturbance observer (NDO is presented to estimate the external disturbance acting on AUV, and an adaptive terminal sliding mode control (ATSMC based on NDO is applied to enhance the depth tracking performance of underactuated AUV considering both internal and external disturbance. Compared with the traditional sliding mode controller, the static error and chattering problem of the depth tracking process have been clearly improved by adopting NDO-based ATSMC. The stability of control system is proven to be guaranteed according to Lyapunov theory. In the end, simulation results imply that the proposed controller owns strong robustness and satisfied control effectiveness in comparison with the traditional controller.
Online Adaptive Error Compensation SVM-Based Sliding Mode Control of an Unmanned Aerial Vehicle
Kaijia Xue
2016-01-01
Full Text Available Unmanned Aerial Vehicle (UAV is a nonlinear dynamic system with uncertainties and noises. Therefore, an appropriate control system has an obligation to ensure the stabilization and navigation of UAV. This paper mainly discusses the control problem of quad-rotor UAV system, which is influenced by unknown parameters and noises. Besides, a sliding mode control based on online adaptive error compensation support vector machine (SVM is proposed for stabilizing quad-rotor UAV system. Sliding mode controller is established through analyzing quad-rotor dynamics model in which the unknown parameters are computed by offline SVM. During this process, the online adaptive error compensation SVM method is applied in this paper. As modeling errors and noises both exist in the process of flight, the offline SVM one-time mode cannot predict the uncertainties and noises accurately. The control law is adjusted in real-time by introducing new training sample data to online adaptive SVM in the control process, so that the stability and robustness of flight are ensured. It can be demonstrated through the simulation experiments that the UAV that joined online adaptive SVM can track the changing path faster according to its dynamic model. Consequently, the proposed method that is proved has the better control effect in the UAV system.
Adaptive Neural-Sliding Mode Control of Active Suspension System for Camera Stabilization
Feng Zhao
2015-01-01
Full Text Available The camera always suffers from image instability on the moving vehicle due to the unintentional vibrations caused by road roughness. This paper presents a novel adaptive neural network based on sliding mode control strategy to stabilize the image captured area of the camera. The purpose is to suppress vertical displacement of sprung mass with the application of active suspension system. Since the active suspension system has nonlinear and time varying characteristics, adaptive neural network (ANN is proposed to make the controller robustness against systematic uncertainties, which release the model-based requirement of the sliding model control, and the weighting matrix is adjusted online according to Lyapunov function. The control system consists of two loops. The outer loop is a position controller designed with sliding mode strategy, while the PID controller in the inner loop is to track the desired force. The closed loop stability and asymptotic convergence performance can be guaranteed on the basis of the Lyapunov stability theory. Finally, the simulation results show that the employed controller effectively suppresses the vibration of the camera and enhances the stabilization of the entire camera, where different excitations are considered to validate the system performance.
Heng Liu; Jin Xu; Yeguo Sun
2013-01-01
X–Z inverted pendulum is a new kind of inverted pendulum and it can move with the combination of the vertical and horizontal forces. This paper addresses the control problem of X-Z inverted pendulum in the presents of system uncertainties and external disturbances, and an adaptive fuzzy sliding mode control approach is proposed. The fuzzy system is used to approximate the system uncertainties and the complicated intermediate control functions in the backstepping control design. To update th...
Fan, Quan-Yong; Yang, Guang-Hong
2016-01-01
This paper is concerned with the problem of integral sliding-mode control for a class of nonlinear systems with input disturbances and unknown nonlinear terms through the adaptive actor-critic (AC) control method. The main objective is to design a sliding-mode control methodology based on the adaptive dynamic programming (ADP) method, so that the closed-loop system with time-varying disturbances is stable and the nearly optimal performance of the sliding-mode dynamics can be guaranteed. In the first step, a neural network (NN)-based observer and a disturbance observer are designed to approximate the unknown nonlinear terms and estimate the input disturbances, respectively. Based on the NN approximations and disturbance estimations, the discontinuous part of the sliding-mode control is constructed to eliminate the effect of the disturbances and attain the expected equivalent sliding-mode dynamics. Then, the ADP method with AC structure is presented to learn the optimal control for the sliding-mode dynamics online. Reconstructed tuning laws are developed to guarantee the stability of the sliding-mode dynamics and the convergence of the weights of critic and actor NNs. Finally, the simulation results are presented to illustrate the effectiveness of the proposed method. PMID:26357411
El Fadil, H.; Giri, F.; Guerrero, Josep M.
2013-01-01
This paper deals with the problem of controlling energy generation systems including fuel cells (FCs) and interleaved boost power converters. The proposed nonlinear adaptive controller is designed using sliding mode control (SMC) technique based on the system nonlinear model. The latter accounts...... for the boost converter large-signal dynamics as well as for the fuel-cell nonlinear characteristics. The adaptive nonlinear controller involves online estimation of the DC bus impedance ‘seen’ by the converter. The control objective is threefold: (i) asymptotic stability of the closed loop system......, (ii) output voltage regulation under bus impedance uncertainties and (iii) equal current sharing between modules. It is formally shown, using theoretical analysis and simulations, that the developed adaptive controller actually meets its control objectives....
Ehsan Maani Miandoab
2013-01-01
Full Text Available Two different control methods, namely, adaptive sliding mode control and impulse damper, are used to control the chaotic vibration of a block on a belt system due to the rate-dependent friction. In the first method, using the sliding mode control technique and based on the Lyapunov stability theory, a sliding surface is determined, and an adaptive control law is established which stabilizes the chaotic response of the system. In the second control method, the vibration of this system is controlled by an impulse damper. In this method, an impulsive force is applied to the system by expanding and contracting the PZT stack according to efficient control law. Numerical simulations demonstrate the effectiveness of both methods in controlling the chaotic vibration of the system. It is shown that the settling time of the controlled system using impulse damper is less than that one controlled by adaptive sliding mode control; however, it needs more control effort.
Adaptive Backstepping Sliding-Mode Control of the Electronic Throttle System in Modern Automobiles
Rui Bai
2014-01-01
Full Text Available In modern automobiles, electronic throttle is a DC-motor-driven valve that regulates air inflow into the vehicle’s combustion system. The electronic throttle is increasingly being used in order to improve the vehicle drivability, fuel economy, and emissions. Electronic throttle system has the nonlinear dynamical characteristics with the unknown disturbance and parameters. At first, the dynamical nonlinear model of the electronic throttle is built in this paper. Based on the model and using the backstepping design technique, a new adaptive backstepping sliding-mode controller of the electronic throttle is developed. During the backstepping design process, parameter adaptive law is designed to estimate the unknown parameter, and sliding-mode control term is applied to compensate the unknown disturbance. The proposed controller can make the actual angle of the electronic throttle track its set point with the satisfactory performance. Finally, a computer simulation is performed, and simulation results verify that the proposed control method can achieve favorable tracking performance.
HU Qinglei; ZHANG Youmin; HUO Xing; XIAO Bing
2011-01-01
A fault tolerant control (FTC) design technique against actuator stuck faults is investigated using integral-type sliding mode control (ISMC) with application to spacecraft attitude maneuvering control system. The principle of the proposed FTC scheme is to design an integral-type sliding mode attitude controller using on-line parameter adaptive updating law to compensate for the effects of stuck actuators. This adaptive law also provides both the estimates of the system parameters and external disturbances such that a prior knowledge of the spacecraft inertia or boundedness of disturbances is not required. Moreover, by including the integral feedback term, the designed controller can not only tolerate actuator stuck faults, but also compensate the disturbances with constant components. For the synthesis of controller, the fault time, patterns and values are unknown in advance, as motivated from a practical spacecraft control application. Complete stability and performance analysis are presented and illustrative simulation results of application to a spacecraft show that high precise attitude control with zero steady-error is successfully achieved using various scenarios of stuck failures in actuators.
Heng Liu
2013-07-01
Full Text Available X–Z inverted pendulum is a new kind of inverted pendulum and it can move with the combination of the vertical and horizontal forces. This paper addresses the control problem of X-Z inverted pendulum in the presents of system uncertainties and external disturbances, and an adaptive fuzzy sliding mode control approach is proposed. The fuzzy system is used to approximate the system uncertainties and the complicated intermediate control functions in the backstepping control design. To update the parameters of the fuzzy system, a proper proportional-integral adaptation law is introduced. Finally, simulation studies are done to show the stabilization of the X-Z inverted pendulum under the proposed method.
A Robust Adaptive Sliding Mode Control for PMLSM with Variable Velocity Profile Over Wide Range
Payam Ghaebi Panah
2015-07-01
Full Text Available An adaptive robust variable structure speed controller is designed for wide range of desired velocity control of a Permanent Magnet Linear Synchronous Motor (PMLSM. This is performed for comprehensive nonlinear model of PMLSM including non-idealities such as detent force, parameter uncertainty, unpredicted disturbance and nonlinear friction. The proposed method is based on the robust Sliding Mode Control (SMC in combination with an adaptive strategy for a wide range of velocity. The simulation results are provided for the above mentioned comprehensive model of PMLSM with a variable velocity profile. Moreover, as an evaluation criterion, a Proportional-Integral (PI controller is designed whose parameters are optimally tuned by the Particle Swarm Optimization (PSO algorithm for better comparison.
Xiao-Zheng Jin
2013-01-01
Full Text Available This paper deals with the asymptotic consensus problem for a class of multiagent systems with time-varying additive actuator faults and perturbed communications. The L2 performance of systems is also considered in the consensus controller designs. The upper and lower bounds of faults and perturbations in actuators and communications and controller gains are assumed to be unknown but can be estimated by designing some indirect adaptive laws. Based on the information from the adaptive estimation mechanism, the distributed robust adaptive sliding mode controllers are constructed to automatically compensate for the effects of faults and perturbations and to achieve any given level of L2 gain attenuation from external disturbance to consensus errors. Through Lyapunov functions and adaptive schemes, the asymptotic consensus of resulting adaptive multiagent system can be achieved with a specified performance criterion in the presence of perturbed communications and actuators. The effectiveness of the proposed design is illustrated via a decoupled longitudinal model of F-18 aircraft.
Asif, Muhammad; Junaid Khan, Muhammad; Cai, Ning
2014-05-01
In this paper, novel adaptive sliding mode dynamic controller with integrator in the loop is proposed for nonholonomic wheeled mobile robot (WMR). The modified kinematics controller is used to generate kinematics velocities of WMR which are subsequently used as the input to adaptive dynamic controller. Actuator dynamics are also derived to generate actuator voltage of WMR through torque and velocity vectors. Stability of both kinematics and dynamic controller is presented using Lyapunov stability analysis. The proposed scheme is verified and validated using computer simulations for tracking the desired trajectory of WMR. The performance of proposed scheme is compared with standard backstepping kinematics controller and classical sliding mode control. In addition, the performance is further compared with standard backstepping kinematics controller with adaptive sliding mode controller without integrator. It is shown that the proposed scheme exhibits zero steady state error, fast error convergence and robustness in the presence of continuous disturbances and uncertainties.
Bu Xiangwei
2015-08-01
Full Text Available A novel adaptive neural control strategy is exploited for the longitudinal dynamics of a generic flexible air-breathing hypersonic vehicle (FAHV. By utilizing functional decomposition method, the dynamics of FAHV is decomposed into the velocity subsystem and the altitude subsystem. For each subsystem, only one neural network is employed for the unknown function approximation. To further reduce the computational burden, minimal-learning parameter (MLP technology is used to estimate the norm of ideal weight vectors rather than their elements. By introducing sliding mode differentiator (SMD to estimate the newly defined variables, there is no need for the strict-feedback form and virtual controller. Hence the developed control law is considerably simpler than the ones derived from back-stepping scheme. Finally, simulation studies are made to illustrate the effectiveness of the proposed control approach in spite of the flexible effects, system uncertainties and varying disturbances.
Abdul Kareem
2012-07-01
Full Text Available This paper presents a novel fuzzy logic based Adaptive Super-twisting Sliding Mode Controller for the control of dynamic uncertain systems. The proposed controller combines the advantages of Second order Sliding Mode Control, Fuzzy Logic Control and Adaptive Control. The reaching conditions, stability and robustness of the system with the proposed controller are guaranteed. In addition, the proposed controller is well suited for simple design and implementation. The effectiveness of the proposed controller over the first order Sliding Mode Fuzzy Logic controller is illustrated by Matlab based simulations performed on a DC-DC Buck converter. Based on this comparison, the proposed controller is shown to obtain the desired transient response without causing chattering and error under steady-state conditions. The proposed controller is able to give robust performance in terms of rejection to input voltage variations and load variations.
Sliding mode control and observation
Shtessel, Yuri; Fridman, Leonid; Levant, Arie
2014-01-01
The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...
Jianxing Liu
2015-01-01
Full Text Available We present an adaptive-gain second order sliding mode (SOSM control applied to a hybrid power system for electric vehicle applications. The main advantage of the adaptive SOSM is that it does not require the upper bound of the uncertainty. The proposed hybrid system consists of a polymer electrolyte membrane fuel cell (PEMFC with a unidirectional DC/DC converter and a Li-ion battery stack with a bidirectional DC/DC converter, where the PEMFC is employed as the primary energy source and the battery is employed as the second energy source. One of the main limitations of the FC is its slow dynamics mainly due to the air-feed system and fuel-delivery system. Fuel starvation phenomenon will occur during fast load demand. Therefore, the second energy source is required to assist the main source to improve system perofrmance. The proposed energy management system contains two cascade control structures, which are used to regulate the fuel cell and battery currents to track the given reference currents and stabilize the DC bus voltage while satisfying the physical limitations. The proposed control strategy is evaluated for two real driving cycles, that is, Urban Dynamometer Driving Schedule (UDDS and Highway Fuel Economy Driving Schedule (HWFET.
Adaptive sliding mode control of the A-axis used for blisk manufacturing
Zhao Pengbing
2014-06-01
Full Text Available As a key assembly in the 5-axis CNC machine tools, positioning precision of the A-axis directly affects the machining accuracy and surface quality of the parts. First of all, mechanical structure and control system of the A-axis are designed. Then, considering the influence of nonlinear friction, backlash, unmodeled dynamics, uncertain cutting force and other external disturbance on the control precision of the A-axis, an adaptive sliding mode control (ASMC based on extended state observer (ESO is proposed. ESO is employed to estimate the state variables of the unknown system and an adaptive law is adopted to compensate for the input dead-zone caused by friction, backlash and other nonlinear characteristics. Finally, stability of the closed-loop system is guaranteed by the Lyapunov theory. Positioning experiments illustrate the perfect estimation of ESO and the stronger anti-interference and robustness of ASMC, which can improve the control precision of the A-axis by about 40 times. Processing experiments show that the ASMC can reduce the waviness, average error and roughness of the processed surface by 35.63%, 31.31% and 30.35%, respectively.
Adaptive sliding mode control of the A-axis used for blisk manufacturing
Zhao Pengbing; Shi Yaoyao
2014-01-01
As a key assembly in the 5-axis CNC machine tools, positioning precision of the A-axis directly affects the machining accuracy and surface quality of the parts. First of all, mechanical structure and control system of the A-axis are designed. Then, considering the influence of nonlin-ear friction, backlash, unmodeled dynamics, uncertain cutting force and other external disturbance on the control precision of the A-axis, an adaptive sliding mode control (ASMC) based on extended state observer (ESO) is proposed. ESO is employed to estimate the state variables of the unknown system and an adaptive law is adopted to compensate for the input dead-zone caused by friction, backlash and other nonlinear characteristics. Finally, stability of the closed-loop system is guaran-teed by the Lyapunov theory. Positioning experiments illustrate the perfect estimation of ESO and the stronger anti-interference and robustness of ASMC, which can improve the control precision of the A-axis by about 40 times. Processing experiments show that the ASMC can reduce the waviness, average error and roughness of the processed surface by 35.63%, 31.31%and 30.35%, respectively.
Automated adaptive sliding mode control scheme for a class of real complicated systems
M Shahi; A H Mazinan
2015-02-01
A class of real complicated systems, including chemical reactions, biological systems, information processing, laser systems, electrical circuits, information exchange, brain activities modelling, secure communication and other related ones can be presented through nonlinear and non-identical hyper-chaotic systems. The main goal of the present investigation is to synchronize two non-identical hyperchaotic master/slave systems, which are given as the models of the complicated systems, based on the realization of an efficient automated adaptive sliding mode control scheme. In the research presented here, the mentioned systems need to be dealt with through the proposed control scheme, since two non-identical systems are completely synchronized. In one such case, the whole of the chosen states of the master and slave systems should be coincided after a few time steps, as long as the effect of the external disturbance, uncertainty and unknown parameters could truly be ignored. Due to the fact that the investigated hyper-chaotic systems have taken into consideration as the representation of a number of complicated processes under mentioned external disturbance, uncertainty and unknown parameters, the traditional control approaches cannot actually be realized, in satisfactory manners.With this purpose, the proposed control scheme has been designed to cope with synchronization error, in a reasonable amount of time, in order to drive applicable hyper-chaotic systems. Consequently, the performance of the proposed control scheme is considered and verified through the numerical simulations.
Chaos control may be understood as the use of tiny perturbations for the stabilization of unstable periodic orbits embedded in a chaotic attractor. The idea that chaotic behavior may be controlled by small perturbations of physical parameters allows this kind of behavior to be desirable in different applications. In this work, chaos control is performed employing a variable structure controller. The approach is based on the sliding mode control strategy and enhanced by an adaptive fuzzy algorithm to cope with modeling inaccuracies. The convergence properties of the closed-loop system are analytically proven using Lyapunov's direct method and Barbalat's lemma. As an application of the control procedure, a nonlinear pendulum dynamics is investigated. Numerical results are presented in order to demonstrate the control system performance. A comparison between the stabilization of general orbits and unstable periodic orbits embedded in chaotic attractor is carried out showing that the chaos control can confer flexibility to the system by changing the response with low power consumption.
Adaptive Sliding Mode Control of Mobile Manipulators with Markovian Switching Joints
Liang Ding; Haibo Gao; Kerui Xia; Zhen Liu; Jianguo Tao; Yiqun Liu
2012-01-01
The hybrid joints of manipulators can be switched to either active (actuated) or passive (underactuated) mode as needed. Consider the property of hybrid joints, the system switches stochastically between active and passive systems, and the dynamics of the jump system cannot stay on each trajectory errors region of subsystems forever; therefore, it is difficult to determine whether the closed-loop system is stochastically stable. In this paper, we consider stochastic stability and sliding mode...
Adaptive Sliding Mode Control of MEMS Gyroscope Based on Neural Network Approximation
Yuzheng Yang
2014-01-01
Full Text Available An adaptive sliding controller using radial basis function (RBF network to approximate the unknown system dynamics microelectromechanical systems (MEMS gyroscope sensor is proposed. Neural controller is proposed to approximate the unknown system model and sliding controller is employed to eliminate the approximation error and attenuate the model uncertainties and external disturbances. Online neural network (NN weight tuning algorithms, including correction terms, are designed based on Lyapunov stability theory, which can guarantee bounded tracking errors as well as bounded NN weights. The tracking error bound can be made arbitrarily small by increasing a certain feedback gain. Numerical simulation for a MEMS angular velocity sensor is investigated to verify the effectiveness of the proposed adaptive neural control scheme and demonstrate the satisfactory tracking performance and robustness.
Guo Haigang
2012-01-01
Full Text Available Combining adaptive fuzzy sliding mode control with fuzzy or variable universe fuzzy switching technique, this study develops two novel direct adaptive schemes for a class of MIMO nonlinear systems with uncertainties and external disturbances. The proposed control schemes consist of fuzzy equivalent control terms, fuzzy switching control terms (in scheme one or variable universe fuzzy switching control terms (in scheme two, and compensation control terms. The compensation control terms are used to relax the assumption on fuzzy approximation error. Based on Lyapunov stability theory, the parameters update laws are adaptively tuned online and the global asymptotic stability of the closed-loop system can be guaranteed. The major contribution of this study is to develop a novel framework for designing direct adaptive fuzzy sliding mode control scheme facing model uncertainties and external disturbances. The derived schemes can effectively solve the chattering problem and the equivalent control calculation in that environment. Simulation results performed on a two-link robotic manipulator demonstrate the feasibility of the proposed control schemes.
Wu Xiaobo; Liu Qing; Zhao Menglian; Chen Mingyang
2013-01-01
An analog implementation of a novel fixed-frequency quasi-sliding-mode controller for single-inductor dual-output (SIDO) buck converter in pseudo-continuous conduction mode (PCCM) with a self-adaptive freewheeling current level (SFCL) is presented.Both small and large signal variations around the operation point are considered to achieve better transient response so as to reduce the cross-regulation of this SIDO buck converter.Moreover,an internal integral loop is added to suppress the steady-state regulation error introduced by conventional PWM-based sliding mode controllers.Instead of keeping it as a constant value,the free-wheeling current level varies according to the load condition to maintain high power efficiency and less cross-regulation at the same time.To verify the feasibility of the proposed controller,an SIDO buck converter with two regulated output voltages,1.8 V and 3.3 V,is designed and fabricated in HEJIAN 0.35 μm CMOS process.Simulation and experiment results show that the transient time of this SIDO buck converter drops to 10 μs while the cross-regulation is reduced to 0.057 mV/mA,when its first load changes from 50 to 100 mA.
Chen, Xiaopeng; Shen, Weixiang; Cao, Zhenwei; Kapoor, Ajay
2014-01-01
In this paper, a novel approach for battery state of charge (SOC) estimation in electric vehicles (EVs) based on an adaptive switching gain sliding mode observer (ASGSMO) has been presented. To design the ASGSMO for the SOC estimation, the state equations based on a battery equivalent circuit model (BECM) are derived to represent dynamic behaviours of a battery. Comparing with a conventional sliding mode observer, the ASGSMO has a capability of minimising chattering levels in the SOC estimation by using the self-adjusted switching gain while maintaining the characteristics of being able to compensate modelling errors caused by the parameter variations of the BECM. Lyapunov stability theory is adopted to prove the error convergence of the ASGSMO for the SOC estimation. The lithium-polymer battery (LiPB) is utilised to conduct experiments for determining the parameters of the BECM and verifying the effectiveness of the proposed ASGSMO in various discharge current profiles including EV driving conditions in both city and suburban.
Jia-Wei Wu
2013-07-01
Full Text Available This paper presents an intelligent control strategy to overcome nonlinear and time-varying characteristics of a diaphragm-type pneumatic vibration isolator (PVI system. By combining an adaptive rule with fuzzy and sliding-mode control, the method has online learning ability when it faces the system’s nonlinear and time-varying behaviors during an active vibration control process. Since the proposed scheme has a simple structure, it is easy to implement. To validate the proposed scheme, a composite control which adopts both chamber pressure and payload velocity as feedback signal is implemented. During experimental investigations, sinusoidal excitation at resonance and random-like signal are input on a floor base to simulate ground vibration. Performances obtained from the proposed scheme are compared with those obtained from passive system and PID scheme to illustrate the effectiveness of the proposed intelligent control.
Adaptive Quasi-Sliding Mode Control for Permanent Magnet DC Motor
Fredy E. Hoyos
2013-01-01
Full Text Available The motor speed of a buck power converter and DC motor coupled system is controlled by means of a quasi-sliding scheme. The fixed point inducting control technique and the zero average dynamics strategy are used in the controller design. To estimate the load and friction torques an online estimator, computed by the least mean squares method, is used. The control scheme is tested in a rapid control prototyping system which is based on digital signal processing for a dSPACE platform. The closed loop system exhibits adequate performance, and experimental and simulation results match.
Adaptive Quasi-Sliding Mode Control for Permanent Magnet DC Motor
Hoyos, Fredy E.; Alejandro Rincón; John Alexander Taborda; Nicolás Toro; Fabiola Angulo
2013-01-01
The motor speed of a buck power converter and DC motor coupled system is controlled by means of a quasi-sliding scheme. The fixed point inducting control technique and the zero average dynamics strategy are used in the controller design. To estimate the load and friction torques an online estimator, computed by the least mean squares method, is used. The control scheme is tested in a rapid control prototyping system which is based on digital signal processing for a dSPACE platform. The closed...
Kong, Xiangxi; Zhang, Xueliang; Chen, Xiaozhe; Wen, Bangchun; Wang, Bo
2016-05-01
In this paper, self- and controlled synchronizations of three eccentric rotors (ERs) in line driven by induction motors rotating in the same direction in a vibrating system are investigated. The vibrating system is a typical underactuated mechanical-electromagnetic coupling system. The analysis and control of the vibrating system convert to the synchronization motion problem of three ERs. Firstly, the self-synchronization motion of three ERs is analyzed according to self-synchronization theory. The criterions of synchronization and stability of self-synchronous state are obtained by using a modified average perturbation method. The significant synchronization motion of three ERs with zero phase differences cannot be implemented according to self-synchronization theory through analysis and simulations. To implement the synchronization motion of three ERs with zero phase differences, an adaptive sliding mode control (ASMC) algorithm based on a modified master-slave control strategy is employed to design the controllers. The stability of the controllers is verified by using Lyapunov theorem. The performances of the controlled synchronization system are presented by simulations to demonstrate the effectiveness of controllers. Finally, the effects of reference speed and non-zero phase differences on the controlled system are discussed to show the strong robustness of the proposed controllers. Additionally, the dynamic responses of the vibrating system in different synchronous states are analyzed.
Zhang, Xiangwen; Xu, Yong; Pan, Ming; Ren, Fenghua
2014-04-01
A sliding-mode observer is designed to estimate the vehicle velocity with the measured vehicle acceleration, the wheel speeds and the braking torques. Based on the Burckhardt tyre model, the extended Kalman filter is designed to estimate the parameters of the Burckhardt model with the estimated vehicle velocity, the measured wheel speeds and the vehicle acceleration. According to the estimated parameters of the Burckhardt tyre model, the tyre/road friction coefficients and the optimal slip ratios are calculated. A vehicle adaptive sliding-mode control (SMC) algorithm is presented with the estimated vehicle velocity, the tyre/road friction coefficients and the optimal slip ratios. And the adjustment method of the sliding-mode gain factors is discussed. Based on the adaptive SMC algorithm, a vehicle's antilock braking system (ABS) control system model is built with the Simulink Toolbox. Under the single-road condition as well as the different road conditions, the performance of the vehicle ABS system is simulated with the vehicle velocity observer, the tyre/road friction coefficient estimator and the adaptive SMC algorithm. The results indicate that the estimated errors of the vehicle velocity and the tyre/road friction coefficients are acceptable and the vehicle ABS adaptive SMC algorithm is effective. So the proposed adaptive SMC algorithm can be used to control the vehicle ABS without the information of the vehicle velocity and the road conditions.
TCP网络的自适应非奇异终端滑模控制%Adaptive nonsingular terminal sliding mode control for TCP networks
叶成荫
2011-01-01
For the problem of congestion control in the TCP Internet, a novel active queue management ( AQM) algorithm based on the nonsingular terminal sliding mode control theory is proposed. A nonsingular terminal sliding mode surface is used to the singularity problem of conventional terminal sliding mode controls, so that the system can be guaranteed to converge to an equilibrium point.Considering UDP flow, an adaptive law based on Lyapunov stability method eliminates the effect from the disturbance of UDP flow. Simulation results demonstrate that the algorithm enables the queue length to converge to set value quickly, keeps the queue oscillation small, and outperforms the conventional IP control and sliding mode control.%针对TCP网络的拥塞控制问题,采用非奇异终端滑模控制理论提出了一种新的主动队列管理算法.采用非奇异终端滑模面以克服传统终端滑模控制的奇异问题,同时确保系统能在有限时间内收敛至平衡点.考虑到UDP流干扰的情况,用Lyapunov稳定性方法给出了一个自适应律来消除UDP流干扰对系统的影响.仿真结果表明,该算法可以使队列长度快速收敛到设定值,同时维持较小的队列振荡,优于传统的滑模控制.
孙美美; 胡云安; 韦建明
2015-01-01
An adaptive sliding mode control scheme was presented for the synchronization of a class of multiwing hyper-chaotic system with uncertainties and unknown external disturbances.The sliding mode control and parameter adaptive principle were designed to realize the synchronization between the master system and slave system.Adaptive control technique and the sliding mode technique were both used to introduce robustness and eliminate systematic uncertainties and affections from external disturbances.It is proved that synchronization errors converge to a small neighbourhood of the origin by using Lyapunov stability theory.Finally,simulation results verified the effectiveness of the proposed con-trol scheme.%研究了一类多涡卷超混沌系统的同步控制问题，同时考虑了不确定项和未知扰动的情况，提出了一种自适应滑模控制方案。综合利用滑模控制技术和自适应控制技术，消除了系统不确定性和未知扰动的影响，对于不确定性和未知扰动具有较好的鲁棒性。利用 Lyapunov 稳定性理论证明了系统同步误差渐近收敛到一个原点的小邻域内，系统渐近稳定。仿真结果验证了该方法的有效性。
Sliding mode control for mobile welding robot
Lü Xueqin; Zhang Ke; Wu Yixiong
2006-01-01
The sliding mode controller of mobile welding robot is established in this paper through applying the method of variable structure control with sliding mode into the control of the mobile welding robot.The traditional switching function smooth method is improved by combining the smoothed switching function with the time-varying control gain.It is shown that the proposed sliding mode controller is robust to bounded external disturbances.Experimental results demonstrate that sliding mode controller algorithm can be used into seam tracking and the tracking system is stable with bounded uncertain disturbance.In the seam tracking process, the robot moves steadily without any obvious chattering.
Brief reviews on suppressing panel flutter vibrations by various active control strategies as well as utilization tunable electrorheological fluids (ERFs) for vibration control of structural systems are presented. Active suppression of the supersonic flutter motion of a simply supported sandwich panel with a tunable ERF interlayer, and coupled to an elastic foundation, is subsequently investigated. The structural formulation is based on the classical beam theory along with the Winkler–Pasternak foundation model, the ER fluid core is modeled as a first-order Kelvin–Voigt material, and the quasi-steady first-order supersonic piston theory is employed to describe the aerodynamic loading. Hamilton’s principle is used to derive a set of fully coupled dynamic equations of motion. The generalized Fourier expansions in conjunction with the Galerkin method are then employed to formulate the governing equations in the state space domain. The critical dynamic pressures at which unstable panel oscillations (coalescence of eigenvalues) occur are obtained via the p-method for selected applied electric field strengths (E = 0,2,4 kV mm−1). The classical Runge–Kutta time integration algorithm is subsequently used to calculate the open-loop aeroelastic response of the system in various basic loading configurations (i.e. uniformly distributed blast, gust, sonic boom, and step loads), with or without an interacting soft/stiff elastic foundation. Finally, a sliding mode control synthesis (SMC) involving the first six natural modes of the structural system is set up to actively suppress the closed-loop system response in supersonic flight conditions and under the imposed excitations. Simulation results demonstrate performance, effectiveness, and insensitivity with respect to the spillover of the proposed SMC-based control system. Limiting cases are considered and good agreements with the data available in the literature as well as with the computations made by using the
Sliding mode control for synchronous electric drives
Ryvkin, Sergey E
2011-01-01
This volume presents the theory of control systems with sliding mode applied to electrical motors and power converters. It demonstrates the methodology of control design and the original algorithms of control and observation. Practically all semiconductor devices are used in power converters, that feed electrical motors, as power switches. A switching mode offers myriad attractive, inherent properties from a control viewpoint, especially a sliding mode. Sliding mode control supplies high dynamics to systems, invariability of systems to changes of their parameters and of exterior loads in combi
Fuzzy Backstepping Sliding Mode Control for Mismatched Uncertain System
H. Q. Hou
2014-06-01
Full Text Available Sliding mode controllers have succeeded in many control problems that the conventional control theories have difficulties to deal with; however it is practically impossible to achieve high-speed switching control. Therefore, in this paper an adaptive fuzzy backstepping sliding mode control scheme is derived for mismatched uncertain systems. Firstly fuzzy sliding mode controller is designed using backstepping method based on the Lyapunov function approach, which is capable of handling mismatched problem. Then fuzzy sliding mode controller is designed using T-S fuzzy model method, it can improve the performance of the control systems and their robustness. Finally this method of control is applied to nonlinear system as a case study; simulation results are also provided the performance of the proposed controller.
This paper describes a nonlinear torque and stator flux controller for three phase induction motor (IM) drives on the basis of a space vector modulation (SVM) scheme. Using the IM fifth order model in a fixed 'ab' axis reference frame with stator currents (isa ,isb) and stator fluxes (ψsa,ψsb) as state variables, a sliding mode (SM) torque and flux controller is designed first in order to track a linear reference model, which has the desired dynamic behaviors for the IM drive system. The SM controller generates the reference voltages (vas*,vbs*) for a two level space vector modulation-pulse width modulation (SVM-PWM) inverter that feeds the motor. Then, the SM controller is combined with an adaptive input-output feedback linearization technique in order to preserve the system robustness with respect to stator and rotor resistances variations and uncertainties. Finally, simulations and comparative experimental results with the proposed control scheme are presented
Yin, Xiu-xing; Lin, Yong-gang; Li, Wei; Liu, Hong-wei; Gu, Ya-jing
2015-09-01
A variable-displacement pump controlled pitch system is proposed to mitigate generator power and flap-wise load fluctuations for wind turbines. The pitch system mainly consists of a variable-displacement hydraulic pump, a fixed-displacement hydraulic motor and a gear set. The hydraulic motor can be accurately regulated by controlling the pump displacement and fluid flows to change the pitch angle through the gear set. The detailed mathematical representation and dynamic characteristics of the proposed pitch system are thoroughly analyzed. An adaptive sliding mode pump displacement controller and a back-stepping stroke piston controller are designed for the proposed pitch system such that the resulting pitch angle tracks its desired value regardless of external disturbances and uncertainties. The effectiveness and control efficiency of the proposed pitch system and controllers have been verified by using realistic dataset of a 750 kW research wind turbine. PMID:26303957
Wallace Moreira Bessa
2010-04-01
Full Text Available This paper presents a detailed discussion about the convergence properties of a variable structure controller for uncertain single-input-single-output nonlinear systems (SISO. The adopted approach is based on the sliding mode control strategy and enhanced by an adaptive fuzzy algorithm to cope with modeling inaccuracies and external disturbances that can arise. The boundedness of all closed-loop signals and the convergence properties of the tracking error are analytically proven using Lyapunov's direct method and Barbalat's lemma. This result corrects flawed conclusions previously reached in the literature. An application of this adaptive fuzzy sliding mode controller to a second-order nonlinear system is also presented. The obtained numerical results demonstrate the improved control system performance.Este trabalho apresenta uma discussão detalhada acerca das propriedades de convergência de um controlador à estrutura variável para sistemas incertos com uma entrada e uma saída (SISO. A abordagem adotada baseia-se na estratégia de controle por modos deslizantes e incorpora um algoritmo difuso adaptativo para compensar imprecisões de modelagem e perturbações externas que possam ocorrer. A limitação de todos os sinais do sistema em malha-fechada e as propriedades de convergência do erro de rastreamento são demonstradas analiticamente através do método direto de Liapunov e do lema de Barbalat. Este resultado corrige conclusões errôneas apresentadas anteriormente na literatura. Uma aplicação do controlador por modos deslizantes difuso adaptativo em um sistema não-linear de segunda ordem também é discutida. Os resultados obtidos numericamente confirmam o desempenho do controlador.
Adaptive ant colony sliding mode control for nonlinear coupling systems%非线性耦合系统的自适应蚁群滑模控制
梁利华; 陈国民; 张松涛
2011-01-01
针对一类多子系统之间具有强耦合关系的非线性系统,提出自适应蚁群滑模控制方法.依据等效滑模控制理论,建立滑模算法控制结构图,用于解耦非线性耦合系统；根据自适应蚁群算法建立了多变量蚁群算法的图形表示,对滑模控制中的滑模面斜率进行优化,来削弱“抖振”现象.该方法可以用较小的计算量对耦合系统自然解耦,并利用蚁群算法的并行特性来优化参数.将该方法应用到三轴摇摆台控制系统中,仿真结果表明,与其他算法相比,超调量减小50％,上升时间和调节时间也明显减小,且有较好的控制效果和鲁棒性.%An adaptive Ant Colony Sliding Mode Control (ACSMC) approach is proposed for a class of nonlinear systems with multi-coupling subsystems for the first time. The structure diagram was established to decouple the systems of nonlinear coupling system based on the equivalent theory of sliding mode control. A multivariate graphical representation of the ant colony algorithm was given to optimize the surface slope of sliding mode control to eliminate the chattering phenomenon. Precise natural decoupling with smaller amount of calculation in coupling system is achieved and use the parallel characteristics of ant colony algorithm to optimize the parameters is employed. By applying this method to three-axis swing platform control system the simulation results prove that compared with other algorithms the proposed approach decreases overshoot 50% and it also reduces the rising time and the settling time significantly and has better effectiveness and robustness.
A Sliding Mode-Multimodel Control with Sliding Mode Observer for a Sensorless Pumping System
Rhif, Ahmed; Kardous, Zohra; Braiek, Naceur Ben Hadj
2013-01-01
This work deals with the design of a sliding mode observer with a multi-surfaces sliding mode multimodel control (SM-MMC) for a mechanical sensorless pumping system. The observer is designed to estimate the speed and the mechanical position of the DC motor operating in the process. Robustness tests validated by simulation show the effectiveness of the sliding mode observer associated with this control approach (SM-MMC).
SLIDING MODE CONTROL FOR ACTIVE AUTOMOBILE SUSPENSIONS
1998-01-01
Nonlinear control methods are presented based on theory of sliding mode control (SMC) or variable structure control (VSC) for application to active automobile suspensions. Requirements of reducing manufacturing cost and energy consumption of the active suspension system may be satisfiedby reasonable design of the sliding surface and hydraulic servo system. Emphasis is placed on the study of the discrete sliding mode control method (DSMC) applicable for a new sort of speed on-off solenoid valves of anti-dust capability and low price. Robustness and effectiveness of the feedback linearized controller in typical road conditions are demonstrated by numerical results fora quarter-car suspension model.
Kobravi, Hamid-Reza; Erfanian, Abbas
2009-08-01
A decentralized control methodology is designed for the control of ankle dorsiflexion and plantarflexion in paraplegic subjects with electrical stimulation of tibialis anterior and calf muscles. Each muscle joint is considered as a subsystem and individual controllers are designed for each subsystem. Each controller operates solely on its associated subsystem, with no exchange of information between the subsystems. The interactions between the subsystems are taken as external disturbances for each isolated subsystem. In order to achieve robustness with respect to external disturbances, unmodeled dynamics, model uncertainty and time-varying properties of muscle-joint dynamics, a robust control framework is proposed which is based on the synergistic combination of an adaptive nonlinear compensator with a sliding mode control and is referred to as an adaptive robust control. Extensive simulations and experiments on healthy and paraplegic subjects were performed to demonstrate the robustness against the time-varying properties of muscle-joint dynamics, day-to-day variations, subject-to-subject variations, fast convergence, stability and tracking accuracy of the proposed method. The results indicate that the decentralized robust control provides excellent tracking control for different reference trajectories and can generate control signals to compensate the muscle fatigue and reject the external disturbance. Moreover, the controller is able to automatically regulate the interaction between agonist and antagonist muscles under different conditions of operating without any preprogrammed antagonist activities.
Yazdanpanah, R.; Soltani, J. [Faculty of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan (Iran); Arab Markadeh, G.R. [Department of Electrical Engineering, Technical Faculty, Shahrekord University, Shahrekord (Iran)
2008-04-15
This paper describes a nonlinear torque and stator flux controller for three phase induction motor (IM) drives on the basis of a space vector modulation (SVM) scheme. Using the IM fifth order model in a fixed 'ab' axis reference frame with stator currents (i{sub sa},i{sub sb}) and stator fluxes ({psi}{sub sa},{psi}{sub sb}) as state variables, a sliding mode (SM) torque and flux controller is designed first in order to track a linear reference model, which has the desired dynamic behaviors for the IM drive system. The SM controller generates the reference voltages (v{sub as}{sup *},v{sub bs}{sup *}) for a two level space vector modulation-pulse width modulation (SVM-PWM) inverter that feeds the motor. Then, the SM controller is combined with an adaptive input-output feedback linearization technique in order to preserve the system robustness with respect to stator and rotor resistances variations and uncertainties. Finally, simulations and comparative experimental results with the proposed control scheme are presented. (author)
Laser autofocusing: a sliding mode approach
Golubovic, Edin; Khalil, Islam S. M.; Kamadan, Abdullah; ŞABANOVIÇ, Asif; Sabanovic, Asif
2010-01-01
Quality of the laser processing depends on many factors, such as overall configuration of the laser workstation, control methods used and quality of the laser beam. Although lasers used in material processing are typically high energy lasers, light beam still needs to be focused in order to achieve higher energy density and smaller final spot size. This paper presents an application of sliding mode to the laser autofocusing system. Autofocusing system consists of photodiode as the measurem...
Adaptive Sliding Mode Pitch Control of Variable-speed Wind Turbines%变速风力发电机组的自适应滑模变桨距控制
何真; 龚春英
2013-01-01
An adaptive global fast terminal sliding mode control method was proposed for the pitch control of variable-speed wind turbines with great uncertainties.The dynamics of the adjustable-pitch wind turbines was modeled.An adaptive fuzzy system was designed to approximate the unknown terms in the model.The sliding mode composed of terminal sliding mode and linear sliding mode was chosen and the adaptive terminal sliding mode pitch controller was proposed.By using Lyapunov stability theorem,the stability of the system was proved,the specific adaptive law was determined and the estimation algorithm was designed to estimate the bound of system uncertainties.The case of the pitch control of the wind turbines operating under natural winds was simulated.The results verify that the system is stable and the output power is steady.%在风力发电系统稳定性优化控制的研究中,针对不确定性的变速风力发电机组的变桨距控制方式系统稳定性差的问题,提出了一种自适应全局快速Terminal滑模控制方法.建立变桨距风力发电机组动力学模型,针对模型中的未知环节,设计了自适应模糊逼近系统.采用由Terminal滑动模态和线性滑动模态组成的滑模模态,采用了自适应Terminal滑模变桨距控制器.根据Lyapunov稳定性理论证明了系统稳定性,并给出了具体的自适应律和不确定项边界的估计算法.对自然风下的机组变桨距控制情况进行了仿真,结果表明系统稳定且输出功率平稳.
Fault detection and fault-tolerant control using sliding modes
Alwi, Halim; Tan, Chee Pin
2011-01-01
""Fault Detection and Fault-tolerant Control Using Sliding Modes"" is the first text dedicated to showing the latest developments in the use of sliding-mode concepts for fault detection and isolation (FDI) and fault-tolerant control in dynamical engineering systems. It begins with an introduction to the basic concepts of sliding modes to provide a background to the field. This is followed by chapters that describe the use and design of sliding-mode observers for FDI using robust fault reconstruction. The development of a class of sliding-mode observers is described from first principles throug
Adaptive fuzzy sliding mode stabilization control for floated inertial platform%浮球式惯导平台的自适应模糊滑模稳定控制
李安梁; 蔡洪; 白锡斌
2013-01-01
A control algorithm of adaptive sliding mode control based on fuzzy logic is proposed for the inertial stabilization problem of the floated inertial platform (FLIP).The sliding mode control was used to solve the parameters uncertainness and unmodeled dynamics of the FLIP, which guarantees the stability and rapidity of the system.Then,by focusing on the design problem of the sliding mode control,the gain of a sliding mode control was adjusted by using the fuzzy logic with an adaptive tuning algorithm,which enhanced the adaptability for random uncertainty and improved the robust performance and the stabilization accuracy of the controller.Finally,the stability and convergence of the control system were proven by using the Lyapunov method.The simulation results demonstrate that the proposed method can eliminate the input chattering of the sliding mode control efficiently,and the inertial stabilization of the FLIP is realized with the accuracy higher than0.1 ″.%针对浮球式惯导平台的惯性空间稳定问题，提出了一种基于模糊逻辑的自适应滑模控制方案。该方法利用滑模控制器保证了系统的稳定性和快速性，解决了浮球式惯导平台参数不确定、未建模动态等未知干扰问题；基于滑模控制器的设计问题，利用模糊逻辑和自适应控制律，调节滑模控制器的参数，估计并补偿系统的外界干扰及不确定性等干扰，增强系统对随机不确定性的适应能力，提高控制系统的鲁棒性和控制精度；利用 Laypunov 方法证明了控制系统的稳定性与收敛性。仿真结果表明，该方法可以有效减低滑模控制控制输入抖振问题，实现浮球式惯导平台的高精度惯性空间稳定，且稳定精度高于0．1″。
Ghabraei, Soheil; Moradi, Hamed; Vossoughi, Gholamreza
2015-09-01
To guarantee the safety and efficient performance of the power plant, a robust controller for the boiler-turbine unit is needed. In this paper, a robust adaptive sliding mode controller (RASMC) is proposed to control a nonlinear multi-input multi-output (MIMO) model of industrial boiler-turbine unit, in the presence of unknown bounded uncertainties and external disturbances. To overcome the coupled nonlinearities and investigate the zero dynamics, input-output linearization is performed, and then the new decoupled inputs are derived. To tackle the uncertainties and external disturbances, appropriate adaption laws are introduced. For constructing the RASMC, suitable sliding surface is considered. To guarantee the sliding motion occurrence, appropriate control laws are constructed. Then the robustness and stability of the proposed RASMC is proved via Lyapunov stability theory. To compare the performance of the purposed RASMC with traditional control schemes, a type-I servo controller is designed. To evaluate the performance of the proposed control schemes, simulation studies on nonlinear MIMO dynamic system in the presence of high frequency bounded uncertainties and external disturbances are conducted and compared. Comparison of the results reveals the superiority of proposed RASMC over the traditional control schemes. RAMSC acts efficiently in disturbance rejection and keeping the system behavior in desirable tracking objectives, without the existence of unstable quasi-periodic solutions. PMID:25983065
Sliding Mode Speed Control for DC Drive Systems
Guldemir, H.
2003-01-01
In this study, the Sliding Mode Control theory of the Variable Structure System has been applied to the speed control of a de motor. The dynamic performance of the sliding mode speed control system has been studied against system parameter variations and external load disturbance and the simulation results are given. The application of the sliding mode control theory to controller design for DC drive control system shows a robust system performance.
Power System Stabilizer Based on Global Fuzzy Sliding Mode Control
Nechadi, E.; Harmas, M. N.
2013-01-01
—Power systems stability is enhanced through a novel stabiliser developed around a fuzzy sliding mode approach. First, sliding mode control is applied to selected operating point based models of a power system separately then fuzzy logic is used to form a global model encompassing the separate subsystems, thus leading to a fuzzy sliding mode power system control. Stability is insured through Lyapunov synthesis. Severe operating conditions are used in a simulation study to test the validity of...
Mohammad Mahdi Ebrahimi
2013-11-01
Full Text Available In this research, an artificial chattering free adaptive fuzzy modified sliding mode control design and application to continuum robotic manipulator has proposed in order to design high performance nonlinear controller in the presence of uncertainties. Regarding to the positive points in sliding mode controller, fuzzy logic controller and online tuning method, the output improves. Each method by adding to the previous controller has covered negative points. The main target in this research is design of model free estimator on-line sliding mode fuzzy algorithm for continuum robot manipulator to reach an acceptable performance. Continuum robot manipulators are highly nonlinear, and a number of parameters are uncertain, therefore design model free controller by both analytical and empirical paradigms are the main goal. Although classical sliding mode methodology has acceptable performance with known dynamic parameters such as stability and robustness but there are two important disadvantages as below: chattering phenomenon and mathematical nonlinear dynamic equivalent controller part. To solve the chattering fuzzy logic inference applied instead of dead zone function. To solve the equivalent problems in classical sliding mode controller this paper focuses on applied on-line tuning method in classical controller. This algorithm works very well in certain and uncertain environment. The system performance in sliding mode controller is sensitive to the sliding function. Therefore, compute the optimum value of sliding function for a system is the next challenge. This problem has solved by adjusting sliding function of the on-line method continuously in real-time. In this way, the overall system performance has improved with respect to the classical sliding mode controller. This controller solved chattering phenomenon as well as mathematical nonlinear equivalent part by applied modified PID supervisory method in modified fuzzy sliding mode controller and
郭亚军; 王晓锋; 马大为; 乐贵高
2011-01-01
A adaptive backstepping sliding mode control approach was introduced to control the pitch motion of a rocket gun. Its control law was proposed to guarantee that the control system was ultimately bounded in a Lyapunov sense and make the servo system could track the instruction of reference position globally and asymptotically. In addition, the sliding mode control can restrain effects of parameter uncertainties and external disturbance. The functions of adaptive mechanism and sliding mode control were analyzed by using simulation under different conditions. The simulation results illustrate that the method is applicable and robust.%针对某火箭炮俯仰运动的位置控制问题,采用了一种自适应反演滑模控制方法.自适应反演控制律保证了闭环系统最终有界,使伺服系统能够全局渐进跟踪参考位置指令,从而达到交流伺服系统稳定跟踪控制的目的,滑模控制抑制了模型参数摄动和外界干扰的影响.通过不同条件下的仿真研究,分析了自适应机制和滑模控制在运动控制中的作用,结果表明该方法具有较强的适应性及鲁棒性.
叶成荫
2011-01-01
For the problem of congestion control in the Internet, a novel active queue management ( AQM ) algorithm based on the sliding mode control theory is proposed. Considering UDP flow, an active queue management algorithm based on adaptive global sliding mode control is designed. The algorithm guarantees the network system robustness during the whole control process and uses RBF neural netword as adaptive law to eliminate the effect from the disturbance of UDP flow. Simulation results demonstrate that the algorithm enables the queue length to converge to set value quickly,keeps the small queue oscillation, and outperforms the conventional IP control and sliding mode control.%针对TCP网络的拥塞控制问题,采用滑模控制理论提出了一种新的主动队列管理算法.考虑到UDP流干扰的情况,设计了基于自适应全局滑模控制的主动队列管理算法.该算法保证网络系统在整个控制过程中的鲁棒性,并且使用RBF神经网络作为自适应律来消除UDP流干扰对系统的影响.仿真结果表明该算法可以使队列长度快速收敛到设定值,同时维持较小的队列振荡,优于传统的PI控制和滑模控制.
A Sliding Mode Multimodel Control for a Sensorless Photovoltaic System
Rhif, Ahmed; Kardous, Zohra; Braiek, Naceur BenHadj
2013-01-01
In this work we will talk about a new control test using the sliding mode control with a nonlinear sliding mode observer, which are very solicited in tracking problems, for a sensorless photovoltaic panel. In this case, the panel system will has as a set point the sun position at every second during the day for a period of five years; then the tracker, using sliding mode multimodel controller and a sliding mode observer, will track these positions to make the sunrays orthogonal to the photovo...
Sliding Mode Robustness Control Strategy for Shearer Height Adjusting System
Xiuping Su
2013-09-01
Full Text Available This paper firstly established mathematical model of height adjusting hydro cylinder of the shearer, as well as the state space equation of the shearer height adjusting system. Secondly we designed a shearer automatic height adjusting controller adopting the sliding mode robustness control strategy. The height adjusting controller includes the sliding mode surface switching function based on Ackermann formula, as well as sliding mode control function with the improved butterworth filter. Then simulation of the height adjustment controller shows that the sliding mode robustness control solves buffeting of typical controller, and achieves automatic control for the rolling drum of the shearer.
Chatter free sliding mode control of a chaotic coal mine power grid with small energy inputs
Xu Yanqing; Jia Feng; Ma Caoyuan; Mao Jiasong; Zhang Shaowei
2012-01-01
An augmented proportional-integral sliding surface was designed for a sliding mode controller.A chatter free sliding mode control strategy for a chaotic coal mine power grid was developed.The stability of the control strategy was proven by Lyapunov stability theorem.The proposed sliding mode control strategy eliminated the chattering phenomenon by replacing the sign function with a saturation function,and by replacing the constant coefficients in the reaching law with adaptive ones.An immune genetic algorithm was used to optimize the parameters in the improved reaching.law.The cut-in time of the controllers was optimized to reduce the peak energy of their output.Simulations showed that the proposed sliding mode controller has good,chatter free performance.
Robust Sliding Mode Control for Tokamaks
I. Garrido
2012-01-01
Full Text Available Nuclear fusion has arisen as an alternative energy to avoid carbon dioxide emissions, being the tokamak a promising nuclear fusion reactor that uses a magnetic field to confine plasma in the shape of a torus. However, different kinds of magnetohydrodynamic instabilities may affect tokamak plasma equilibrium, causing severe reduction of particle confinement and leading to plasma disruptions. In this sense, numerous efforts and resources have been devoted to seeking solutions for the different plasma control problems so as to avoid energy confinement time decrements in these devices. In particular, since the growth rate of the vertical instability increases with the internal inductance, lowering the internal inductance is a fundamental issue to address for the elongated plasmas employed within the advanced tokamaks currently under development. In this sense, this paper introduces a lumped parameter numerical model of the tokamak in order to design a novel robust sliding mode controller for the internal inductance using the transformer primary coil as actuator.
Sliding Mode Control of Steerable Needles.
Rucker, D Caleb; Das, Jadav; Gilbert, Hunter B; Swaney, Philip J; Miga, Michael I; Sarkar, Nilanjan; Webster, Robert J
2013-10-01
Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation. PMID:25400527
Sliding mode control the delta-sigma modulation approach
Sira-Ramírez, Hebertt
2015-01-01
This monograph presents a novel method of sliding mode control for switch-regulated nonlinear systems. The Delta Sigma modulation approach allows one to implement a continuous control scheme using one or multiple, independent switches, thus effectively merging the available linear and nonlinear controller design techniques with sliding mode control. Sliding Mode Control: The Delta-Sigma Modulation Approach, combines rigorous mathematical derivation of the unique features of Sliding Mode Control and Delta-Sigma modulation with numerous illustrative examples from diverse areas of engineering. In addition, engineering case studies demonstrate the applicability of the technique and the ease with which one can implement the exposed results. This book will appeal to researchers in control engineering and can be used as graduate-level textbook for a first course on sliding mode control.
Advances in sliding mode control concept, theory and implementation
Janardhanan, S; Spurgeon, Sarah
2013-01-01
The sliding mode control paradigm has become a mature technique for the design of robust controllers for a wide class of systems including nonlinear, uncertain and time-delayed systems. This book is a collection of plenary and invited talks delivered at the 12th IEEE International Workshop on Variable Structure System held at the Indian Institute of Technology, Mumbai, India in January 2012. After the workshop, these researchers were invited to develop book chapters for this edited collection in order to reflect the latest results and open research questions in the area. The contributed chapters have been organized by the editors to reflect the various themes of sliding mode control which are the current areas of theoretical research and applications focus; namely articulation of the fundamental underpinning theory of the sliding mode design paradigm, sliding modes for decentralized system representations, control of time-delay systems, the higher order sliding mode concept, results applicable to nonlinear an...
Sliding mode controller for signal input multiple state submarine system
Sliding mode control design has become a popular choice for controlling non-linear dynamical systems. This paper, explores the dynamics of a submarine and represents the same in state space form. It also investigates the potential of sliding mode controller for a single input multiple state system of a submarine. Mathematical derivation of the controller is presented and it is proved that the sliding mode controllers is robust to changes in operating conditions. The problem of chattering in sliding mode controller design is discussed and remedy of this problem is suggested. Simulation studies are carried out which demonstrate that the sliding mode controller can efficiency be used as a heading controller for the submarine under investigation. (author)
Guaranteed performance in reaching mode of sliding mode controlled systems
G K Singh; K E Holé
2004-02-01
Conventionally, the parameters of a sliding mode controller (SMC) are selected so as to reduce the time spent in the reaching mode. Although, an upper bound on the time to reach (reaching time) the sliding surface is easily derived, performance guarantee in the state/error space needs more consideration. This paper addresses the design of constant plus proportional rate reaching law-based SMC for second-order nonlinear systems. It is shown that this controller imposes a bounding second-order error-dynamics, and thus guarantees robust performance during the reaching phase. The choice of the controller parameters based on the time to reach a desirable level of output tracking error (OTE), rather than on the reaching time is proposed. Using the Lyapunov theory, it is shown that parameter selections, based on the reaching time criterion, may need substantially larger time to achieve the OTE. Simulation results are presented for a nonlinear spring-massdamper system. It is seen that parameter selections based on the proposed OTE criterion, result in substantially quicker tracking, while using similar levels of control effort.
Kong, Xiangxi; Zhang, Xueliang; Chen, Xiaozhe; Wen, Bangchun; Wang, Bo
2016-05-01
In this paper, phase and speed synchronization control of four eccentric rotors (ERs) driven by induction motors in a linear vibratory feeder with unknown time-varying load torques is studied. Firstly, the electromechanical coupling model of the linear vibratory feeder is established by associating induction motor's model with the dynamic model of the system, which is a typical under actuated model. According to the characteristics of the linear vibratory feeder, the complex control problem of the under actuated electromechanical coupling model converts to phase and speed synchronization control of four ERs. In order to keep the four ERs operating synchronously with zero phase differences, phase and speed synchronization controllers are designed by employing adaptive sliding mode control (ASMC) algorithm via a modified master-slave structure. The stability of the controllers is proved by Lyapunov stability theorem. The proposed controllers are verified by simulation via Matlab/Simulink program and compared with the conventional sliding mode control (SMC) algorithm. The results show the proposed controllers can reject the time-varying load torques effectively and four ERs can operate synchronously with zero phase differences. Moreover, the control performance is better than the conventional SMC algorithm and the chattering phenomenon is attenuated. Furthermore, the effects of reference speed and parametric perturbations are discussed to show the strong robustness of the proposed controllers. Finally, experiments on a simple vibratory test bench are operated by using the proposed controllers and without control, respectively, to validate the effectiveness of the proposed controllers further.
Accurate Sliding-Mode Control System Modeling for Buck Converters
Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.
2007-01-01
This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively...... modeling the hysteretic comparator as an infinite gain. Correct prediction of output impedance is shown to be enabled by the use of a more elaborate, finite-gain model of the hysteretic comparator, which takes the effects of time delay and finite switching frequency into account. The demonstrated modeling...... approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30V/3A buck converter....
Adaptive Sliding Control for a Class of Fractional Commensurate Order Chaotic Systems
Jian Yuan
2015-01-01
Full Text Available This paper proposes adaptive sliding mode control design for a class of fractional commensurate order chaotic systems. We firstly introduce a fractional integral sliding manifold for the nominal systems. Secondly we prove the stability of the corresponding fractional sliding dynamics. Then, by introducing a Lyapunov candidate function and using the Mittag-Leffler stability theory we derive the desired sliding control law. Furthermore, we prove that the proposed sliding manifold is also adapted for the fractional systems in the presence of uncertainties and external disturbances. At last, we design a fractional adaptation law for the perturbed fractional systems. To verify the viability and efficiency of the proposed fractional controllers, numerical simulations of fractional Lorenz’s system and Chen’s system are presented.
Robust sliding mode control applied to double Inverted pendulum system
A three hierarchical sliding mode control is presented for a class of an underactuated system which can overcome the mismatched perturbations. The considered underactuated system is a double inverted pendulum (DIP), can be modeled by three subsystems. Such structure allows the construction of several designs of hierarchies for the controller. For all hierarchical designs, the asymptotic stability of every layer sliding mode surface and the sliding mode surface of subsystems are proved theoretically by Barbalat's lemma. Simulation results show the validity of these methods.
Sliding mode control of switching power converters techniques and implementation
Tan, Siew-Chong; Tse, Chi-Kong
2011-01-01
Sliding Mode Control of Switching Power Converters: Techniques and Implementation is perhaps the first in-depth account of how sliding mode controllers can be practically engineered to optimize control of power converters. A complete understanding of this process is timely and necessary, as the electronics industry moves toward the use of renewable energy sources and widely varying loads that can be adequately supported only by power converters using nonlinear controllers.Of the various advanced control methods used to handle the complex requirements of power conversion systems, sliding mode c
Fault Reconstruction Using Sliding Mode Observers
K. Hakiki
2006-01-01
Full Text Available In this study, a nonlinear sliding observer is proposed to explicitly reconstruct fault signals. The novelty lies in the application of the equivalent output injection concept. Previous work in the area of fault detection has used disruption of the sliding motion to detect faults. The aim of the present study was to design a robust observer that slides in the presence of faults based on the response of the estimated outputs of the system. A numerical example of the application to an inverted pendulum mounted on a cart is provided to demonstrate the approach
Sliding mode controller of rf cavity tuning loop
Ferrite tuned cavities must operate under a wide range of accelerating frequencies. The tuning is done by modulating the current in the coil surrounding the ferrite. Feedback controllers are used to improve the tuning condition by sensing the phase error. The design of controllers currently in use is based on classical frequency domain techniques. Classical controllers in this application are sensitive to variations in the tuning system parameters. Also, these controllers generally fail to provide correct transient response when there is beam in the cavity, since the beam loading changes the transfer function of the system. We have designed a robust and adaptive controller based on sliding mode techniques for a cavity tuning system on the ISIS synchrotron. The techniques are extendable to other systems. 7 refs., 3 figs
Sliding mode controller for RF cavity tuning loop
Ferrite tuned cavities must operate under a wide range of accelerating frequencies. The tuning is done by modulating the current in the coil surrounding the ferrite. Feedback controllers are used to improve the tuning condition by sensing the phase error. The design of controllers currently in use is based on classical frequency domain techniques. Classical controllers in this application are sensitive to variations in the tuning system parameters. Also, these controllers generally fail to provide correct transient response when there is beam in the cavity, since the beam loading changes the transfer function of the system. The authors have designed a robust and adaptive controller based on sliding mode techniques for a cavity tuning system on the ISIS synchrotron. The techniques are extendable to other systems
A novel higher order sliding mode control scheme
Defoort, Michael; Floquet, Thierry; Kökösy, Annemarie; Perruquetti, Wilfrid
2009-01-01
A higher order sliding mode control algorithm is proposed for a class of uncertain multi-input multi-output nonlinear systems. This problem can be viewed as the finite time stabilization of a higher order input-output dynamic system with bounded uncertainties. The developed control scheme is based on geometric homogeneity and sliding mode control. The proposed procedure provides explicit conditions on the controller parameters and guarantees robustness against uncertainties. An illustrative e...
Sliding mode observers and observability singularity in chaotic synchronization
L. Boutat-Baddas; J. P. Barbot; Boutat, D.; R. Tauleigne
2004-01-01
We present a new secured data transmission based on a chaotic synchronization and observability singularity. For this, we adopt an approach based on an inclusion of the message in the system structure and we use a sliding mode observer for system with unknown input in order to recover the information. We end the paper with an example of chaotic system with an observability bifurcation. Moreover, this example highlights some benefits of the so-called step-by-step sliding mode observer.
Sliding mode control on electro-mechanical systems
Utkin Vadim I.
2002-01-01
Full Text Available The first sliding mode control application may be found in the papers back in the 1930s in Russia. With its versatile yet simple design procedure the methodology is proven to be one of the most powerful solutions for many practical control designs. For the sake of demonstration this paper is oriented towards application aspects of sliding mode control methodology. First the design approach based on the regularization is generalized for mechanical systems. It is shown that stability of zero dynamics should be taken into account when the regular form consists of blocks of second-order equations. Majority of applications in the paper are related to control and estimation methods of automotive industry. New theoretical methods are developed in the context of these studies: sliding made nonlinear observers, observers with binary measurements, parameter estimation in systems with sliding mode control.
陈志勇; 陈力
2012-01-01
研究了柔性空间机械臂协调运动控制及柔性振动抑制问题。利用假设模态法及系统动量守恒关系,导出了空间机械臂的系统动力学模型。基于混合滑模思想,针对系统惯性参数存在不确定的复杂情况,提出了一种柔性空间机械臂本体姿态、关节协调运动的自适应变结构控制方案。该文所引入的混合滑模由频率成形最优滑模及终端滑模两部分组成。前者用于抑制系统柔性杆件的振动,后者则是为了保证系统追踪误差在有限时间内的收敛性。此外,上述控制方案由于在控制过程中无需预知系统的柔性变量,因此可有效避免对系统柔性状态变量进行实时地测量与反馈,较适于实际应用。仿真运算,证实了所提控制方法的有效性。%The coordinated motion control and flexible vibration suppression problems of flexible space manipulator are studied.With the assumed mode method and the linear momentum conservation of the system,the system dynamics model of the space manipulator is derived.Based on the hybrid sliding mode concept,an adaptive variable structure control scheme is proposed for the flexible space manipulator to achieve the coordinated motion between the base＇s attitude and the arm＇s joints,which accounts for the uncertainty in inertial parameters.The hybrid sliding mode introduced consists of two parts,the frequency shaped optimal sliding mode and the terminal sliding mode.The former is used to suppress the vibration of flexible link of the system,and the latter is utilized to guarantee the convergence of system tracking errors in finite time.Moreover,the control scheme proposed does not require the foreknowledge of flexible variables in control.Thus,it can effectively avoid the real-time measurements and feedbacks of system flexible variables,and be more suitable for practical applications.Simulation results demonstrate the effectiveness of the proposed control scheme.
Second order sliding mode control for a quadrotor UAV.
Zheng, En-Hui; Xiong, Jing-Jing; Luo, Ji-Liang
2014-07-01
A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method. PMID:24751475
Theory of psychological adaptive modes.
Lehti, Juha
2016-05-01
When an individual is facing a stressor and normal stress-response mechanism cannot guarantee sufficient adaptation, special emotional states, adaptive modes, are activated (for example a depressive reaction). Adaptive modes are involuntary states of mind, they are of comprehensive nature, they interfere with normal functioning, and they cannot be repressed or controlled the same way as many emotions. Their transformational nature differentiates them from other emotional states. The object of the adaptive mode is to optimize the problem-solving abilities according to the situation that has provoked the mode. Cognitions and emotions during the adaptive mode are different than in a normal mental state. These altered cognitions and emotional reactions guide the individual to use the correct coping skills in order to deal with the stressor. Successful adaptation will cause the adaptive mode to fade off since the adaptive mode is no longer necessary, and the process as a whole will lead to raised well-being. However, if the adaptation process is inadequate, then the transformation period is prolonged, and the adaptive mode will turn into a dysfunctional state. Many psychiatric disorders are such maladaptive processes. The maladaptive processes can be turned into functional ones by using adaptive skills that are used in functional adaptive processes. PMID:27063089
基于自适应滑模的喷水推进船舶航向控制%Adaptive Sliding Mode for Course Tracking Control of a Waterjet Propulsion Ship
曾薄文; 朱齐丹; 宋洋
2011-01-01
关于船舶航行优化控制,针对喷水推进船舶的航向稳定性控制问题,根据模型中非线性水动力不确定性和外界干扰,提出了基于PID增益调节的自适应滑模控制方法, 并利用Lyapunov稳定性理论证明控制方法的稳定性.控制方法对于模型参数摄动和外界干扰有较好的鲁棒性,PID增益参数的选择可通过在线自适应学习获得,采用边界层方法对设计的滑模控制器的高频抖振加以合理抑制.以一艘喷水推进船舶为例,进行了航向改变的仿真,结果表明设计的控制器具有船舶操纵的良好动态性能,且具有超调小、鲁棒性强的优点,更加符合船舶航向实时控制的工程要求.%In this paper an adaptive sliding mode controller with PID gain tuning method is presented for a waterjet propulsion ship, the model' s nonlinear hydrodynamic uncertainties and environmental disturbances are also considered for controller desisn, and the stability property of proposed controller can be guaranteed according to the Lyapunov stability theorem. Moreover, system robustness against parameter variations and external disturbances are obtained by the proposed control method, and suitable PID control gain parameters can be systematically on-line computed based on adaptive law. The boundary layer condition is adopted to reduce the high frequency chattering in the switching part of the sliding mode controller. Finally, an example with a waterjet propulsion ship is shown to verify the effectiveness of the proposed controller. Simulations, with ship course changing 10°, illustrate that the design controller has good dynamic performances without little overshooting and strong robustness, and can meet the engineering requirement of the ship course real-time control.
Adaptive Structural Mode Control Project
National Aeronautics and Space Administration — M4 Engineering proposes the development of an adaptive structural mode control system. The adaptive control system will begin from a "baseline" dynamic model of the...
Sliding-Mode Synchronization Control for Uncertain Fractional-Order Chaotic Systems with Time Delay
Haorui Liu
2015-06-01
Full Text Available Specifically setting a time delay fractional financial system as the study object, this paper proposes a single controller method to eliminate the impact of model uncertainty and external disturbances on the system. The proposed method is based on the stability theory of Lyapunov sliding-mode adaptive control and fractional-order linear systems. The controller can fit the system state within the sliding-mode surface so as to realize synchronization of fractional-order chaotic systems. Analysis results demonstrate that the proposed single integral, sliding-mode control method can control the time delay fractional power system to realize chaotic synchronization, with strong robustness to external disturbance. The controller is simple in structure. The proposed method was also validated by numerical simulation.
Zebin Yang
2016-06-01
Full Text Available In order to improve the performance of the Bearingless Induction Motor (BIM under large disturbances (such as parameter variations and load disturbances, an adaptive variable-rated sliding mode controller (ASMC is designed to obtain better performance of the speed regulation system. Firstly, the L 1 norm of state variables is applied to the conventional exponential reaching law and an adaptive variable-rated exponential reaching law is proposed to reduce system chattering and improve bad convergence performance of the sliding mode variable structure. Secondly, an integral sliding-mode hyper plane is produced according to the speed error in speed regulation system of BIM. Current signal is extracted by the combination of the sliding-mode hyper plane, the electromagnetic torque and the equation of motion. Finally, the feedback speed can adjust operating state adaptively according to speed error and make system chattering-free moving. The simulation and experiment results show that the proposed ASMC can not only enhance the robustness of the system’s uncertainties, but also improve the dynamic performance and suppress system chattering.
Sliding mode tracking control for miniature unmanned helicopters
Xian Bin
2015-02-01
Full Text Available A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter’s dynamic model is divided into two subsystems, such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles’ dynamic effects and external disturbances. The global asymptotic stability (GAS of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportional-integral-derivative (PID and linear-quadratic regulator (LQR cascaded controller in the presence of wind gust disturbances.
Optimal Sliding Mode Controllers for Attitude Stabilization of Flexible Spacecraft
Chutiphon Pukdeboon
2011-01-01
Full Text Available The robust optimal attitude control problem for a flexible spacecraft is considered. Two optimal sliding mode control laws that ensure the exponential convergence of the attitude control system are developed. Integral sliding mode control (ISMC is applied to combine the first-order sliding mode with optimal control and is used to control quaternion-based spacecraft attitude manoeuvres with external disturbances and an uncertainty inertia matrix. For the optimal control part the state-dependent Riccati equation (SDRE and optimal Lyapunov techniques are employed to solve the infinite-time nonlinear optimal control problem. The second method of Lyapunov is used to guarantee the stability of the attitude control system under the action of the proposed control laws. An example of multiaxial attitude manoeuvres is presented and simulation results are included to verify the usefulness of the developed controllers.
Cascade Control of Magnetic Levitation with Sliding Modes
Eroğlu Yakup
2016-01-01
Full Text Available The effectiveness and applicability of magnetic levitation systems need precise feedback control designs. A cascade control approach consisting of sliding mode control plus sliding mode control (SMC plus SMC is designed to solve position control problem and to provide a high control performance and robustness to the magnetic levitation plant. It is shown that the SMC plus SMC cascade controller is able to eliminate the effects of the inductance related uncertainties of the electromagnetic coil of the plant and achieve a robust and precise position control. Experimental and numerical results are provided to validate the effectiveness and feasibility of the method.
Sliding mode observers and observability singularity in chaotic synchronization
Boutat-Baddas L.
2004-01-01
Full Text Available We present a new secured data transmission based on a chaotic synchronization and observability singularity. For this, we adopt an approach based on an inclusion of the message in the system structure and we use a sliding mode observer for system with unknown input in order to recover the information. We end the paper with an example of chaotic system with an observability bifurcation. Moreover, this example highlights some benefits of the so-called step-by-step sliding mode observer.
王宇飞; 姜长生
2011-01-01
The design of variable universe direct adaptive fuzzy sliding mode control law to a class of uncertain nonlinear systems is considered. According to the tracking error, the contraction and expansion factors of variable universe fuzzy controller are tuned on-line, so the nonlinear part is estimated by the fuzzy system. Robust controller is constructed to attenuate fuzzy approximation errors and enhance the whole system performance. The adjusting law of the adaptive parameters is given. By using Lyapunov theory, it is proven that the closed-loop is uniformly stable.Finally, the flight control system of near space vehicle (NSV) under hypersonic condition is designed by using the proposed method. The results show the fine performance of the method.%考虑一类非线性不确定系统的直接自适应变论域模糊滑模控制问题.根据跟踪误差在线调整伸缩因子,使变论域模糊系统一致逼近被控对象中的非线性部分.通过引入鲁棒自适应控制器,消除了模糊建模误差,提高了系统的动态性能.给出了系统自适应参数的调整律,并基于Lyapunov理论证明了闭环系统一致稳定.最后,将该算法用于近空间飞行器(near space vehicle,NSV)姿态控制系统的设计,仿真结果表明了该算法的有效性.
Fuzzy Sliding Mode Controller Design Using Takagi-Sugeno Modelled Nonlinear Systems
S. Bououden
2013-01-01
Full Text Available Adaptive fuzzy sliding mode controller for a class of uncertain nonlinear systems is proposed in this paper. The unknown system dynamics and upper bounds of the minimum approximation errors are adaptively updated with stabilizing adaptive laws. The closed-loop system driven by the proposed controllers is shown to be stable with all the adaptation parameters being bounded. The performance and stability of the proposed control system are achieved analytically using the Lyapunov stability theory. Simulations show that the proposed controller performs well and exhibits good performance.
Robust antisynchronization of chaos using sliding mode control strategy
Amit Mondal; Mitul Islam; Nurul Islam
2015-01-01
The paper proposes a sliding mode control strategy-based scheme for achieving anti-synchronization between two coupled non-linear chaotic systems. The method works irrespective of whether the systems under consideration possess or lack inverse symmetry. Using a linear sliding surface, a sliding mode control input and a non-linear coupling function are designed that synchronizes the systems antiphase. Finite-time convergence of the method is established. The controller is also robust to all forms of bounded perturbations and this robustness can be easily achieved by tuning of a single controller parameter and introduction of a control vector. The controller is also made chattering-free by producing a continuous analogue of the discontinuous control input. The effectiveness of the method is established by implementing it to antisynchronize chaotic Sprott systems and Rossler systems. The results are also verified through numerical simulation work.
Sliding-Mode Control of PEM Fuel Cells
Kunusch, Cristian; Mayosky, Miguel
2012-01-01
Recent advances in catalysis technologies and new materials make fuel cells an economically appealing and clean energy source with massive market potential in portable devices, home power generation and the automotive industry. Among the more promising fuel-cell technologies are proton exchange membrane fuel cells (PEMFCs). Sliding-Mode Control of PEM Fuel Cells demonstrates the application of higher-order sliding-mode control to PEMFC dynamics. Fuel-cell dynamics are often highly nonlinear and the text shows the advantages of sliding modes in terms of robustness to external disturbance, modelling error and system-parametric disturbance using higher-order control to reduce chattering. Divided into two parts, the book first introduces the theory of fuel cells and sliding-mode control. It begins by contextualising PEMFCs both in terms of their development and within the hydrogen economy and today’s energy production situation as a whole. The reader is then guided through a discussion of fuel-cell operation pr...
Sliding mode control based guidance law with impact angle constraint
Zhao Yao; Sheng Yongzhi; Liu Xiangdong
2014-01-01
The terminal guidance problem for an unpowered lifting reentry vehicle against a sta-tionary target is considered. In addition to attacking the target with high accuracy, the vehicle is also expected to achieve a desired impact angle. In this paper, a sliding mode control (SMC)-based guidance law is developed to satisfy the terminal angle constraint. Firstly, a specific sliding mode function is designed, and the terminal requirements can be achieved by enforcing both the sliding mode function and its derivative to zero at the end of the flight. Then, a backstepping approach is used to ensure the finite-time reaching phase of the sliding mode and the analytic expression of the control effort can be obtained. The trajectories generated by this method only depend on the initial and terminal conditions of the terminal phase and the instantaneous states of the vehicle. In order to test the performance of the proposed guidance law in practical application, numerical simulations are carried out by taking all the aerodynamic parameters into consideration. The effec-tiveness of the proposed guidance law is verified by the simulation results in various scenarios.
Discrete-Time Sliding Mode Control with a Disturbance Estimator
Monsees, G.; Scherpen, J.M.A.
2001-01-01
This paper presents a novel output-based, discrete-time, sliding mode controller design methodology. Output based controllers with and without disturbance estimation are presented. First several existing discrete-time reaching conditions are analyzed and compared. From these methods the linear reach
Digital Sliding Mode Control of Anti-Lock Braking System
MITIC, D. B.
2013-02-01
Full Text Available The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.
Sliding Mode Control (SMC) of Robot Manipulator via Intelligent Controllers
Kapoor, Neha; Ohri, Jyoti
2016-06-01
Inspite of so much research, key technical problem, naming chattering of conventional, simple and robust SMC is still a challenge to the researchers and hence limits its practical application. However, newly developed soft computing based techniques can provide solution. In order to have advantages of conventional and heuristic soft computing based control techniques, in this paper various commonly used intelligent techniques, neural network, fuzzy logic and adaptive neuro fuzzy inference system (ANFIS) have been combined with sliding mode controller (SMC). For validation, proposed hybrid control schemes have been implemented for tracking a predefined trajectory by robotic manipulator, incorporating structured and unstructured uncertainties in the system. After reviewing numerous papers, all the commonly occurring uncertainties like continuous disturbance, uniform random white noise, static friction like coulomb friction and viscous friction, dynamic friction like Dhal friction and LuGre friction have been inserted in the system. Various performance indices like norm of tracking error, chattering in control input, norm of input torque, disturbance rejection, chattering rejection have been used. Comparative results show that with almost eliminated chattering the intelligent SMC controllers are found to be more efficient over simple SMC. It has also been observed from results that ANFIS based controller has the best tracking performance with the reduced burden on the system. No paper in the literature has found to have all these structured and unstructured uncertainties together for motion control of robotic manipulator.
Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles
ZHOU Jun; WANG Zhi; ZHOU Feng-qi
2007-01-01
The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent "explosion of terms". Owing to the upper bounds of the uncertainties are difficult to obtain in advance,adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.
Sliding Mode Attitude Control for Magnetic Actuated Satellite
Wisniewski, Rafal
1998-01-01
Magnetic torquing is attractive as a control principle on small satellites. The actuation principle is to use the interaction between the earth's magnetic field and magnetic field generated by a coil set in the satellite. This control principle is inherently nonlinear, and difficult to use because...... control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis attitude control. This paper deals with three-axis stabilization of a low earth orbit satellite. The problem of controlling the...... spacecraft attitude using only magnetic torquing is realized in the form of the sliding mode control. A three dimensional sliding manifold is proposed, and it is shown that the satellite motion on the sliding manifold is asymptotically stable...
Rudi Uswarman
2014-07-01
Full Text Available This paper presents global sliding mode control and conventional sliding mode control for stabilization position of a levitation object. Sliding mode control will be robusting when in sliding mode condition. However, it is not necessarily robust at attaining phase. In the global sliding mode control, the attaining motion phase was eliminated, so that the robustness of the controller can be improved. However, the value of the parameter uncertainties needs to be limited. Besides that, the common problem in sliding mode control is high chattering phenomenon. If the chattering is too large, it can make the system unstable due the limited ability of electronics component. The strategy to overcome the chattering phenomenon is needed. Based on simulation and experimental results, the global sliding mode control has better performance than conventional sliding mode control.
Path Following of an Underactuated AUV Based on Fuzzy Backstepping Sliding Mode Control
Xiao Liang
2016-06-01
Full Text Available This paper addresses the path following problem of an underactuated autonomous underwater vehicle (AUV with the aim of dealing with parameter uncertainties and current disturbances. An adaptive robust control system was proposed by employing fuzzy logic, backstepping and sliding mode control theory. Fuzzy logic theory is adopted to approximate unknown system function, and the controller was designed by combining sliding mode control with backstepping thought. Firstly, the longitudinal speed was controlled, then the yaw angle was made as input of path following error to design the calm function and the change rate of path parameters. The controller stability was proved by Lyapunov stable theory. Simulation and outfield tests were conducted and the results showed that the controller is of excellent adaptability and robustness in the presence of parameter uncertainties and external disturbances. It is also shown to be able to avoid the chattering of AUV actuators.
Farzin Piltan
2013-06-01
Full Text Available Both fuzzy logic and sliding mode can compensate the steady-state error of proportional-derivative (PD control. This paper presents parallel sliding mode compensations for fuzzy PD controllers. The asymptotic stability of fuzzy PD control with first-order sliding mode compensation in the parallel structure is proven. For the parallel structure, the finite time convergence with a super-twisting second-order sliding-mode is guaranteed.
Advances and applications in sliding mode control systems
Zhu, Quanmin
2015-01-01
This book describes the advances and applications in Sliding mode control (SMC) which is widely used as a powerful method to tackle uncertain nonlinear systems. The book is organized into 21 chapters which have been organised by the editors to reflect the various themes of sliding mode control. The book provides the reader with a broad range of material from first principles up to the current state of the art in the area of SMC and observation presented in a clear, matter-of-fact style. As such it is appropriate for graduate students with a basic knowledge of classical control theory and some knowledge of state-space methods and nonlinear systems. The resulting design procedures are emphasized using Matlab/Simulink software.
Recent advances in sliding modes from control to intelligent mechatronics
Efe, Mehmet
2015-01-01
This volume is dedicated to Professor Okyay Kaynak to commemorate his life time impactful research and scholarly achievements and outstanding services to profession. The 21 invited chapters have been written by leading researchers who, in the past, have had association with Professor Kaynak as either his students and associates or colleagues and collaborators. The focal theme of the volume is the Sliding Modes covering a broad scope of topics from theoretical investigations to their significant applications from Control to Intelligent Mechatronics.
Stability notions and Lyapunov functions for sliding mode control systems
Polyakov, Andrey; Fridman, Leonid
2014-01-01
The paper surveys mathematical tools required for stability and convergence analysis of modern sliding mode control systems. Elements of Filippov theory of differential equations with discontinuous right-hand sides and its recent extensions are discussed. Stability notions (from Lyapunov stability (1982) to fixed-time stability (2012)) are observed. Concepts of generalized derivatives and non-smooth Lyapunov functions are considered. The generalized Lyapunov theorems for stability analysis an...
A high performance switching audio amplifier using sliding mode control
Pillonnet, Gael; Cellier, Rémy; Abouchi, Nacer; Chiollaz, Monique
2008-01-01
International audience The switching audio amplifiers are widely used in various portable and consumer electronics due to their high efficiency, but suffers from low audio performances due to inherent nonlinearity. This paper presents an integrated class D audio amplifier with low consumption and high audio performances. It includes a power stage and an efficient control based on sliding mode technique. This monolithic class D amplifier is capable of delivering up to 1W into 8Ω load at les...
SIMULATION OF BLDC MOTOR CONTROL USING SLIDING MODE CONTROL TECHNIQUE
Namita P. Galphade; Subhash S. Sankeshwari
2015-01-01
Mostly, Brushless DC motors have been used in various industrial and domestic applications because of its advantages like simple structure, large torque, long use time, good speed regulation. Generally the BLDCM systems have uncertain and nonlinear characteristics which degrade performance of controllers. Based on these reasons, Sliding Mode Control (SMC) is one of the popular control strategies to deal with the nonlinear uncertain system. In This work implemented a SMC scheme for effective s...
Robust Control of a Brushless Servo Motor Using Sliding Mode
Radita Arindya
2012-01-01
The application of sliding mode techniques the position control of a brushless servo motor is discussed. Such control laws are well suited for electric power inverter. However, high frequency commutations are avoided due to the mechanical systems. Various recent schemes are studied and operated to derive control solutions which are technically feasible. In spite of straightforward applications the resulting systems show robust performances to parametric variations and disturbances. Robustness...
Sliding mode control of a magnetic levitation system
N. F. Al-Muthairi
2004-01-01
Full Text Available Sliding mode control schemes of the static and dynamic types are proposed for the control of a magnetic levitation system. The proposed controllers guarantee the asymptotic regulation of the statesof the system to their desired values. Simulation results of the proposed controllers are given to illustrate the effectiveness of them. Robustness of the control schemes to changes in the parameters of the system is also investigated.
Multi-mode sliding mode control for precision linear stage based on fixed or floating stator
Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei
2016-02-01
This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.
Maximum Power Point Tracking Based on Sliding Mode Control
Nimrod Vázquez
2015-01-01
Full Text Available Solar panels, which have become a good choice, are used to generate and supply electricity in commercial and residential applications. This generated power starts with the solar cells, which have a complex relationship between solar irradiation, temperature, and output power. For this reason a tracking of the maximum power point is required. Traditionally, this has been made by considering just current and voltage conditions at the photovoltaic panel; however, temperature also influences the process. In this paper the voltage, current, and temperature in the PV system are considered to be a part of a sliding surface for the proposed maximum power point tracking; this means a sliding mode controller is applied. Obtained results gave a good dynamic response, as a difference from traditional schemes, which are only based on computational algorithms. A traditional algorithm based on MPPT was added in order to assure a low steady state error.
Farzin Piltan
2013-07-01
Full Text Available This paper describes the design and implementation of robust nonlinear sliding mode control strategies for robot manipulators whose dynamic or kinematic models are uncertain. Therefore a fuzzy sliding mode tracking controller for robot manipulators with uncertainty in the kinematic and dynamic models is design and analyzes. The controller is developed based on the unit quaternion representation so that singularities associated with the otherwise commonly used three parameter representations are avoided. Simulation results for a planar application of the continuum or hyper-redundant robot manipulator (CRM are provided to illustrate the performance of the developed adaptive controller. These manipulators do not have rigid joints, hence, they are difficult to model and this leads to significant challenges in developing high-performance control algorithms. In this research, a joint level controller for continuum robots is described which utilizes a fuzzy methodology component to compensate for dynamic uncertainties.
许叙遥; 林辉
2013-01-01
To improve the robustness and control precision of single-axis roll stabilized servo platform (SRSSP) in strap-down inertial navigation system, a novel servo control method based on adaptive nonsingular and fast terminal dynamic sliding mode is presented. The principle of SRSSP is introduced, and an adaptive nonsingular and fast terminal sliding mode control method with steady-state error and chatting is analyzed. Based on three-loop PID servo control ideology, a linear segment is configured by system state variables, then a nonsingular and fast terminal dynamic sliding mode controller is developed based on the segment, and the boundary of parameter uncertainty and external disturbance is estimated by adaptive law. The new control method can realize accurate control of the position and speed. Meanwhile, the chattering in sliding mode is greatly attenuated. Simulation results show that the new sliding mode servo control method is feasible, and can improve the robustness and accuracy of the servo platform.%为提高捷联导航系统中的单轴滚转稳定伺服平台鲁棒性和控制精度，提出了一种基于自适应非奇异快速终端的动态滑模控制方法。介绍了单轴滚转稳定伺服平台原理，分析自适应非奇异快速终端滑模控制方法以及存在稳态误差和抖振问题。在借鉴三环PID伺服控制思想基础上，首先将状态变量构成线性滑模面，在该线性滑模面上形成非奇异快速终端滑模控制器，并采用自适应律来估计扰动上限。能够实现位置和速度的精确控制，大大削弱滑模抖振。仿真结果表明，基于自适应非奇异快速终端速度动态滑模控制方法合理可行，提高了单轴滚转稳定平台收敛速度、鲁棒性和控制精度。
Permanent Magnet DC Motor Sliding Mode Control System
Vaez-Zadeh, S.; Zamanian, M.
2000-09-01
In this paper a sliding mode controller (SMC) is designed for a permanent magnet, direct current (PMDC) motor to enhance the motor performance in the presence of unwanted uncertainties. Both the electrical and mechanical signals are used as the inputs to the SMC. The complete motor control system is simulated on a personal computer with different design parameters and desirable system performance is obtained. The experimental implementation of the motor control system is also presented. The test results confirm the simulation results and validate the proposed control system.
Observer Based Sliding Mode Attitude Control: Theoretical and Experimental Results
U. Jørgensen
2011-07-01
Full Text Available In this paper we present the design of a sliding mode controller for attitude control of spacecraft actuated by three orthogonal reaction wheels. The equilibrium of the closed loop system is proved to be asymptotically stable in the sense of Lyapunov. Due to cases where spacecraft do not have angular velocity measurements, an estimator for the generalized velocity is derived and asymptotic stability is proven for the observer. The approach is tested on an experimental platform with a sphere shaped Autonomous Underwater Vehicle SATellite: AUVSAT, developed at the Norwegian University of Science and Technology.
A sliding mode observer for hemodynamic characterization under modeling uncertainties
Zayane, Chadia
2014-06-01
This paper addresses the case of physiological states reconstruction in a small region of the brain under modeling uncertainties. The misunderstood coupling between the cerebral blood volume and the oxygen extraction fraction has lead to a partial knowledge of the so-called balloon model describing the hemodynamic behavior of the brain. To overcome this difficulty, a High Order Sliding Mode observer is applied to the balloon system, where the unknown coupling is considered as an internal perturbation. The effectiveness of the proposed method is illustrated through a set of synthetic data that mimic fMRI experiments.
Decentralized sliding mode control of a building using MR dampers
This paper presents the structural control results of shaking table tests for a steel frame structure in order to evaluate the performance of a number of proposed semi-active control algorithms using multiple magnetorheological (MR) dampers. The test structure is a six-story steel frame equipped with MR dampers. Four different cases of damper arrangement in the structure are selected for the control study. In experimental tests, the El Centro earthquake and Kobe earthquake ground motion data are used as excitations. Further, several decentralized sliding mode control algorithms are developed in this paper specifically for applications of MR dampers in building structures. Various control algorithms are used for the semi-active control studies, including the proposed decentralized sliding mode control (DSMC), LQR control, and passive-on and passive-off control. Each control algorithm is formulated specifically for the use of MR dampers installed in building structures. Additionally, each algorithm uses measurements of the device velocity and device drift for the determination of the control action to ensure that the algorithm can be implemented in a physical structure. The performance of each algorithm is evaluated based on the results of shaking table tests, and the advantages of each algorithm are compared and discussed. The reduction of story drifts and floor accelerations throughout the structure is examined
Sliding mode control of electromagnetic tethered satellite formation
Hallaj, Mohammad Amin Alandi; Assadian, Nima
2016-08-01
This paper investigates the control of tethered satellite formation actuated by electromagnetic dipoles and reaction wheels using the robust sliding mode control technique. Generating electromagnetic forces and moments by electric current coils provides an attractive control actuation alternative for tethered satellite system due to the advantages of no propellant consumption and no obligatory rotational motion. Based on a dumbbell model of tethered satellite in which the flexibility and mass of the tether is neglected, the equations of motion in Cartesian coordinate are derived. In this model, the J2 perturbation is taken into account. The far-field and mid-field models of electromagnetic forces and moments of two satellites on each other and the effect of the Earth's magnetic field are presented. A robust sliding mode controller is designed for precise trajectory tracking purposes and to deal with the electromagnetic force and moment uncertainties and external disturbances due to the Earth's gravitational and magnetic fields inaccuracy. Numerical simulation results are presented to validate the effectiveness of the developed controller and its superiority over the linear controller.
Sliding Mode Control Strategy for Wind Turbine Power Maximization
Oscar Barambones
2012-07-01
Full Text Available The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a sliding mode control for variable speed wind turbine that incorporates a doubly fed induction generator is described. The electrical system incorporates a wound rotor induction machine with back-to-back three phase power converter bridges between its rotor and the grid. In the presented design the so-called vector control theory is applied, in order to simplify the electrical equations. The proposed control scheme uses stator flux-oriented vector control for the rotor side converter bridge control and grid voltage vector control for the grid side converter bridge control. The stability analysis of the proposed sliding mode controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory. Finally simulated results show, on the one hand, that the proposed controller provides high-performance dynamic characteristics, and on the other hand, that this scheme is robust with respect to the uncertainties that usually appear in the real systems.
Hierarchical sliding mode control for under-actuated cranes design, analysis and simulation
Qian, Dianwei
2015-01-01
This book reports on the latest developments in sliding mode overhead crane control, presenting novel research ideas and findings on sliding mode control (SMC), hierarchical SMC and compensator design-based hierarchical sliding mode. The results, which were previously scattered across various journals and conference proceedings, are now presented in a systematic and unified form. The book will be of interest to researchers, engineers and graduate students in control engineering and mechanical engineering who want to learn the methods and applications of SMC.
Switched Reluctance Generator Output Voltage Ripple Reduction Based on Fuzzy Sliding Mode
Xia Fei; Xia Zongze; Huang Xiaobo; Wang Yun
2015-01-01
Aiming at the problem of Switched Reluctance Generator output voltage ripple, this paper designs a fuzzy sliding mode controller based on the analysis of various factors affecting the output voltage ripple. The traditional sliding mode controller has quick convergence, but it has chattering problem. This paper introduces the fuzzy control to select the appropriate sliding mode gain. It can combine with traditional angle control to adjust the output voltage by adjusting the conduction angle. I...
Designing of proportional sliding mode controller for linear one stage inverted pendulum
2011-01-01
The control of Inverted Pendulum (IP) is a hugely complex task. A great deal of nonlinearity is present inherently and as well as affected by the surrounding external conditions. The sliding mode controller (SMC) is very robust inherently. It is used in this paper to control the IP. This paper examines the designing of sliding mode controller (SMC) for a linear inverted pendulum (IP). The paper highlights the important features of the sliding mode and also throws ample lights on the designing...
2014-01-01
A terminal sliding mode controller with nonlinear disturbance observer is investigated to control mobile wheeled inverted pendulum system. In order to eliminate the main drawback of the sliding mode control, “chattering” phenomenon, and for compensation of the model uncertainties and external disturbance, we designed a nonlinear disturbance observer of the mobile wheeled inverted pendulum system. Based on the nonlinear disturbance observer, a terminal sliding mode controller is also proposed....
Ahmed M. Kassem; Ali Mohamed Yousef
2012-01-01
A position control of DC motor servo drive based on the Sliding Mode (SM) approach is presented. The modeling and analysis of the servo DC motor are obtained. The Sliding Mode Controller (SMC) design changes such that its performance is substantially improved. To improve the controller performance in steady stat (zero error) the Integral Sliding Mode Controller (ISMC) is used. Since the main drawback of SMC is a phenomenon, the so-called chattering, resulting from discontinuous controllers. A...
Analysis of an ACC System for Sliding Mode and MPC under Transitional Manoeuvers
Zeeshan Ali Memon
2012-10-01
Full Text Available Two different control algorithms, sliding mode and MPC (Model Predictive Control are employed to analyse the performance of a linear vehicle model equipped with an ACC (Adaptive Cruise Control system. Both controllers are analysed under critical TM (Transitional Maneuvers to investigate their suitability for the ACC system. The simulation results, for the same scenario, from both controllers\\' approach have been compared. The results show that the MPC is more robust than the SMC (Sliding Model Controller. The results show that the SMC algorithm is not suitable for the proposed vehicle model. The shortcomings of the SMC have been highlighted and the comparisons are made with the previous studies. The proposed approach can be useful for the selection of the appropriate controller for the given application.
Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede
A family of speed-sensorless sliding-mode observers for induction motors has been developed. Three topologies have been investigated in order to determine their feasibility, parameter sensitivity and practical applicability. The salient feature of all schemes is that they do not require the rotor...... speed adaptation, that is, they are inherently sensorless observers. The most versatile is a dual-reference-frame observer. The other two schemes, implemented in stator frame and rotor frame, respectively, are simpler and are insensitive to detuning some of the motor parameters. Main theoretical aspects...
Ahcene Boubakir; Fares Boudjema; Salim Labiod
2009-01-01
The aim of this paper is to develop a neuro-fuzzy-sliding mode controller (NFSMC) with a nonlinear sliding surface for a coupled tank system.The main purpose is to eliminate the chattering phenomenon and to overcome the problem of the equivalent control computation.A first-order nonlinear sliding surface is presented,on which the developed sliding mode controller (SMC) is based.Mathematical proof for the stability and convergence of the system is presented.In order to reduce the chattering in SMC,a fixed boundary layer around the switch surface is used.Within the boundary layer,where the fuzzy logic control is applied,the chattering phenomenon,which is inherent in a sliding mode control,is avoided by smoothing the switch signal.Outside the boundary,the sliding mode control is applied to drive the system states into the boundary layer.Moreover,to compute the equivalent controller,a feed-forward neural network (NN) is used.The weights of the net are updated such that the corrective control term of the NFSMC goes to zero.Then,this NN also alleviates the chattering phenomenon because a big gain in the corrective control term produces a more serious chattering than a small gain.Experimental studies carried out on a coupled tank system indicate that the proposed approach is good for control applications.
Robust fuzzy control for stochastic Markovian jumping systems via sliding mode method
Chen, Bei; Jia, Tinggang; Niu, Yugang
2016-07-01
This paper considers the problem of sliding mode control for stochastic Markovian jumping systems by means of fuzzy method. The Takagi-Sugeno (T-S) fuzzy stochastic model subject to state-dependent noise is presented. A key feature in this work is to remove the restricted condition that each local system model had to share the same input channel, which is usually assumed in some existing results. The integral sliding surface is constructed for every mode and the connections among various sliding surfaces are established via a set of coupled matrices. Moreover, the present sliding mode controller including the transition rates of modes can cope with the effect of Markovian switching. It is shown that both the reachability of sliding surfaces and the stability of sliding mode dynamics can be ensured. Finally, numerical simulation results are given.
Hybrid Fuzzy Sliding Mode Controller for Timedelay System
N. K. Yadav
2013-07-01
Full Text Available This paper is concerned with the problems of stability analysis and stabilization control design for a class of discrete-time T-S fuzzy systems with state-delay for multi-input and multi-output. The nonlinear fuzzy controller helps to overcome the problems of the ill - defined model of the systems, which are creating the undesirable performance. . Here sliding surface is being designed for error function of nonlinear system and sliding mode control is being designed here. The switching surface is being proven for its asymptotic stability. The generated error signal and change of error signal will be utilized for application heuristic knowledge to design the rule base in the fuzzy logic control and fuzzy logic controller is designed here. The proposed technique also brings in a systematic approach to the fuzzy logic control, thus overcoming lots of heuristics that were in vogue with earlier fuzzy logic applications. Fuzzy logic control has been applied to a second order model of a roll autopilot. It has been found that the proposed scheme is robust and works satisfactorily even when parameters are perturbed as much as fifteen percent of their geometric mean value. This designed algorithm will be more effective for highly unstable nonlinear systems such as aerospace system.
Fault tolerant control schemes using integral sliding modes
Hamayun, Mirza Tariq; Alwi, Halim
2016-01-01
The key attribute of a Fault Tolerant Control (FTC) system is its ability to maintain overall system stability and acceptable performance in the face of faults and failures within the feedback system. In this book Integral Sliding Mode (ISM) Control Allocation (CA) schemes for FTC are described, which have the potential to maintain close to nominal fault-free performance (for the entire system response), in the face of actuator faults and even complete failures of certain actuators. Broadly an ISM controller based around a model of the plant with the aim of creating a nonlinear fault tolerant feedback controller whose closed-loop performance is established during the design process. The second approach involves retro-fitting an ISM scheme to an existing feedback controller to introduce fault tolerance. This may be advantageous from an industrial perspective, because fault tolerance can be introduced without changing the existing control loops. A high fidelity benchmark model of a large transport aircraft is u...
Longitudinal tire force estimation based on sliding mode observer
El Hadri, A.; Cadiou, J.C.; M' Sirdi, N.K. [Versailles Univ., Paris (France). Lab. de Robotique; Beurier, G.; Delanne, Y. [Lab. Central des Ponts, Centre de Nantes (France)
2001-07-01
This paper presents an estimation method for vehicle longitudinal dynamics, particularly the tractive/braking force. The estimation can be used to detect a critical driving situation to improve security. It can be used also in several vehicle control systems. The main characteristics of the vehicle longitudinal dynamics were taken into account in the model used to design an observer and computer simulations. The state variables are the angular wheel velocity, vehicle velocity and the longitudinal tire force. The proposed differential equation of the tractive/braking force is derived using the concept of relaxation length. The observer designed is based on the sliding mode approach using only the angular wheel velocity measurement. The proposed method of estimation is verified through a one-wheel simulation model with a ''Magic formula'' tire model. Simulations results show an excellent reconstruction of the tire force. (orig.)
Speed Synchronization of web winding System with Sliding Mode Control
Hachemi Glaoui
2013-02-01
Full Text Available A continuous web winding system is a large-scale, complex interconnected dynamic system with numerous tension zones to transport the web while processing it. There are two control schemes for large-scale system control: the centralized scheme and the decentralized scheme. Centralized control is the traditional control method, which considers all the information about the system to be a single dynamic model and design a control system for this model. A speed synchronization control strategy for multiple induction motors, based on adjacent cross-coupling control structure, is developed by employing total sliding mode control method. The proposed control strategy is to stabilize speed tracking of each induction motor while synchronizing its speed with the speed of the other motors so as to make speed synchronization error amongst induction motors converge to zero. The global stability and the convergence of the designed controller are proved by using Lyapunov method. Simulation results demonstrate the effectiveness of the proposed method.
Integral Sliding Mode Control Design for Electronic Throttle Valve System
Shibly Ahmed AL-Samarraie
2015-09-01
Full Text Available One of the major components in an automobile engine is the throttle valve part. It is used to keep up with emissions and fuel efficiency low. Design a control system to the throttle valve is newly common requirement trend in automotive technology. The non-smoothness nonlinearity in throttle valve model are due to the friction model and the nonlinear spring, the uncertainty in system parameters and non-satisfying the matching condition are the main obstacles when designing a throttle plate controller. In this work, the theory of the Integral Sliding Mode Control (ISMC is utilized to design a robust controller for the Electronic Throttle Valve (ETV system. From the first instant, the electronic throttle valve dynamics is represented by the nominal system model, this model is not affected by system parameters uncertainty and the non-smooth nonlinearities. This is a consequence of applying the integral sliding mode control. The ISMC consists of two part; the first is the nominal control which is used to control the nominal system, while the second is a discontinuous part which is used to eliminate the effects of the parameters uncertainty and the non-smooth nonlinearities from system model. These features for the ISMC are proved mathematically and demonstrated numerically via seven numerical simulations and for different desired trajectories. The simulation results clarify that for different system parameters, the ETV behaves as a nominal system. This enables to freely and precisely select the system response characteristics and the time required for the throttle angle to reach the desired value. Moreover the ability to deal with the chattering problem is demonstrated through the worked simulation tests, where the chattering is eliminated via approximating the signum function by arc tan function.
Functional Based Adaptive and Fuzzy Sliding Controller for Non-Autonomous Active Suspension System
Huang, Shiuh-Jer; Chen, Hung-Yi
In this paper, an adaptive sliding controller is developed for controlling a vehicle active suspension system. The functional approximation technique is employed to substitute the unknown non-autonomous functions of the suspension system and release the model-based requirement of sliding mode control algorithm. In order to improve the control performance and reduce the implementation problem, a fuzzy strategy with online learning ability is added to compensate the functional approximation error. The update laws of the functional approximation coefficients and the fuzzy tuning parameters are derived from the Lyapunov theorem to guarantee the system stability. The proposed controller is implemented on a quarter-car hydraulic actuating active suspension system test-rig. The experimental results show that the proposed controller suppresses the oscillation amplitude of the suspension system effectively.
Zhang, Kangkang; Jiang, Bin; Yan, Xing-Gang; Mao, Zehui
2016-07-01
This paper considers incipient sensor fault detection issue for a class of nonlinear systems with "observer unmatched" uncertainties. A particular fault detection sliding mode observer is designed for the augmented system formed by the original system and incipient sensor faults. The designed parameters are obtained using LMI and line filter techniques to guarantee that the generated residuals are robust to uncertainties and that sliding motion is not destroyed by faults. Then, three levels of novel adaptive thresholds are proposed based on the reduced order sliding mode dynamics, which effectively improve incipient sensor faults detectability. Case study of on the traction system in China Railway High-speed is presented to demonstrate the effectiveness of the proposed incipient senor faults detection schemes. PMID:27156675
A novel sliding-mode control of induction motor using space vector modulation technique.
Fu, Tian-Jun; Xie, Wen-Fang
2005-10-01
This paper presents a novel sliding-mode control method for torque control of induction motors. The control principle is based on sliding-mode control combined with space vector modulation technique. The sliding-mode control contributes to the robustness of induction motor drives, and the space vector modulation improves the torque, flux, and current steady-state performance by reducing the ripple. The Lyapunov direct method is used to ensure the reaching and sustaining of sliding mode and stability of the control system. The performance of the proposed system is compared with those of conventional sliding-mode controller and classical PI controller. Finally, computer simulation results show that the proposed control scheme provides robust dynamic characteristics with low torque ripple. PMID:16294775
Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots With Unknown Sliding
Mingyue Cui; Dihua Sun; Weining Liu; Min Zhao; Xiaoyong Liao
2012-01-01
An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time‐varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the ...
Power generation plants are intrinsically complex systems due to their numerous internal components. Higher energy efficiency in power plants is now achieved through employing combined cycles. In this article, an adaptive robust Sliding Mode Controller (SMC) is designed to overcome the faults in Heat Recovery Steam Generator boilers (HRSG boilers) as one of the main parts of a combined cycle plant. On condition that a fault occurs in the HRSG boiler, the control system must be able to reconfigure its parameters to maintain the admissible thresholds in dynamic variables such as drum pressure, steam temperature, and drum water level. To achieve good performance for the boiler, the proposed adaptive robust SMC shall conquer the effects of faults and uncertainties by estimating their upper bounds adaptively, and force the outputs of the multivariable boiler to track the outputs of a desired multivariable reference model. Manipulating a suitable control input and using second-order sliding mode control strategy, the output tracking error slides to zero on a PID sliding surface. Besides tracking, the controlled boiler tolerates faults in system matrix, faults in input matrix, and external disturbance signal. Numerical simulations confirm the effectiveness of the proposed FTC (Fault-Tolerant Control) system for an uncertain non-minimum phase HRSG boiler. Highlights: ► This paper proposes a PID-based adaptive second-order sliding mode controller (SMC). ► SMC is robust to actuator and sensor faults and tracks outputs of a reference system. ► SMC is used in fault tolerant control of a heat recovery steam generator boilers. ► Boiler and reference system have different number of states and inputs. ► Performance of SMC is investigated with different faults scenarios in simulations.
Integral sliding mode control for a class of nonlinear neutral systems with time-varying delays
This paper focuses on sliding mode control problems for a class of nonlinear neutral systems with time-varying delays. An integral sliding surface is firstly constructed. Then it finds a useful criteria to guarantee the global stability for the nonlinear neutral systems with time-varying delays in the specified switching surface, whose condition is formulated as linear matrix inequality. The synthesized sliding mode controller guarantees the reachability of the specified sliding surface. Finally, a numerical simulation validates the effectiveness and feasibility of the proposed technique. (general)
Kinect-Based Sliding Mode Control for Lynxmotion Robotic Arm
Ismail Ben Abdallah
2016-01-01
Full Text Available Recently, the technological development of manipulator robot increases very quickly and provides a positive impact to human life. The implementation of the manipulator robot technology offers more efficiency and high performance for several human’s tasks. In reality, efforts published in this context are focused on implementing control algorithms with already preprogrammed desired trajectories (passive robots case or trajectory generation based on feedback sensors (active robots case. However, gesture based control robot can be considered as another channel of system control which is not widely discussed. This paper focuses on a Kinect-based real-time interactive control system implementation. Based on LabVIEW integrated development environment (IDE, a developed human-machine-interface (HMI allows user to control in real time a Lynxmotion robotic arm. The Kinect software development kit (SDK provides a tool to keep track of human body skeleton and abstract it into 3-dimensional coordinates. Therefore, the Kinect sensor is integrated into our control system to detect the different user joints coordinates. The Lynxmotion dynamic has been implemented in a real-time sliding mode control algorithm. The experimental results are carried out to test the effectiveness of the system, and the results verify the tracking ability, stability, and robustness.
Van Es, Simone L; Kumar, Rakesh K; Pryor, Wendy M; Salisbury, Elizabeth L; Velan, Gary M
2015-09-01
To determine whether cytopathology whole slide images and virtual microscopy adaptive tutorials aid learning by postgraduate trainees, we designed a randomized crossover trial to evaluate the quantitative and qualitative impact of whole slide images and virtual microscopy adaptive tutorials compared with traditional glass slide and textbook methods of learning cytopathology. Forty-three anatomical pathology registrars were recruited from Australia, New Zealand, and Malaysia. Online assessments were used to determine efficacy, whereas user experience and perceptions of efficiency were evaluated using online Likert scales and open-ended questions. Outcomes of online assessments indicated that, with respect to performance, learning with whole slide images and virtual microscopy adaptive tutorials was equivalent to using traditional methods. High-impact learning, efficiency, and equity of learning from virtual microscopy adaptive tutorials were strong themes identified in open-ended responses. Participants raised concern about the lack of z-axis capability in the cytopathology whole slide images, suggesting that delivery of z-stacked whole slide images online may be important for future educational development. In this trial, learning cytopathology with whole slide images and virtual microscopy adaptive tutorials was found to be as effective as and perceived as more efficient than learning from glass slides and textbooks. The use of whole slide images and virtual microscopy adaptive tutorials has the potential to provide equitable access to effective learning from teaching material of consistently high quality. It also has broader implications for continuing professional development and maintenance of competence and quality assurance in specialist practice. PMID:26093936
Yigeng Huangfu; Ruiqing Ma; Abdellatif Miraoui
2012-01-01
This paper mainly discussed a method of high-frequency second-order sliding mode control for Buck converter in wind power systems. Because the wind energy of nature is always unpredictable and intermittent, the robust control such as sliding mode control is adopted in past literatures. In order to remove the high frequency chattering problem when the traditional sliding mode achieves convergence, the second order sliding mode algorithm is reviewed firstly. Meanwhile, the Buck converter taken ...
Sliding mode control of a stand-alone wound rotor synchronous generator
Muñoz Aguilar, Raúl Santiago; Dòria Cerezo, Arnau; Fossas Colet, Enric; Cardoner Parpal, Rafel
2011-01-01
This paper presents a sliding mode control for a wound rotor synchronous machine acting as an isolated generator. The standard dq model of the machine is connected to a resistive load. A switching function is defined in order to fulfill control objectives, and the ideal sliding dynamics is proved to be stable. From the desired surface, the standard sliding methodology is applied to obtain a robust and very simple controller. Numerical simulations and experimental results ...
程东升; 张建武; 叶晓峰; 黄维纲
2003-01-01
A sliding mode control approach based on the feedback linearization is proposed for the electrically controllable clutch of AMT vehicles. The nonlinear dynamic model for the hydraulic actuator associated with clutch is established. By means of the exact feedback linearization procedure of differential geometry, an equivalent, fully controllable and linear model is derived via a homomorphic transformation for the AMT clutch system.Furthermore, a sliding mode control is introduced to improve robustness. The tracking tests are performed using the sliding mode control on a Santana LX passenger car, and the experimental results prove that this nonlinear controller is of fine robustness and high degree of tracking accuracy.
Design of Sliding Mode Controller Enhanced by Fuzzy Logic Algorithm for Industrial Robot
Vijay Tiwari
2013-11-01
Full Text Available In this paper a sliding mode control enhanced by fuzzy logic algorithm method is proposed for the robust tracking control of industrial robot manipulator. The proposed controller ensures the advantage of fuzzy logic algorithm and sliding mode control. There are two parts of the proposed method: first the design of sliding mode control for robust stability and second the development of fuzzy logic algorithms to reduce chattering effectively. The stability of control is proven by Lyapunov stability method and the performance of tracking error is shown in a table by using RMS value.
A NEW SLIDING MODE CONTROL FOR A CLASS OF UNCERTAIN TIME-DELAY CHAOTIC SYSTEMS
LI LI-XIANG; PENG HAI-PENG; GUAN BAO-ZHU; XU JIN-MING
2001-01-01
We propose a new sliding mode control scheme for a class of uncertain time-delay chaotic systems. It is shown that a linear time invariant system with the desired system dynamics is used as a reference model for the output of a time-delay chaotic system to track. A sliding mode controller is then designed to drive the output of the time-delay chaotic system to track the desired linear system. On the sliding mode, the output of the controlled time-delay chaotic system can behave like the desired linear system. A simulation example is given in support of the proposed control scheme.
Sliding mode pulse-width modulation technique for direct torque controlled induction motor drive
Bounadja, M.; Belarbi, A. W.; Belmadani, B.
2010-05-01
This paper presents a novel pulse-width modulation technique based sliding mode approach for direct torque control of an induction machine drive. Methodology begins with a sliding mode control of machine's torque and stator flux to generate the reference voltage vector and to reduce parameters sensitivity. Then, the switching control of the three-phase inverter is developed using sliding mode concept to make the system tracking reference voltage inputs. The main features of the proposed methodologies are the high tracking accuracy and the much easier implementation compared to the space vector modulation. Simulations are carried out to confirm the effectiveness of proposed control algorithms.
王庆龙; 张兴; 张崇巍
2014-01-01
编码器的使用降低了永磁同步电机矢量控制系统的可靠性和耐用性，且某些场合无法安装编码器。理论上可以通过永磁同步电机的电压和电流实时计算出电机的转速和转子位置角度。该文提出了一种基于双滑模模型参考自适应系统(model reference adaptive system，MRAS)的永磁同步电机无位置传感器控制策略。其中，参考模型为永磁电机本身，可调模型为永磁电机电流模型。利用两模型输出的偏差构造了2个滑模面，将通过滑模算法获得的等效控制进行运算即可获得电机的转速和转子位置角度，并分别用于矢量控制系统的速度调节和坐标变换。在理论分析的基础上进行了仿真研究，仿真结果表明所提出的观测方法是有效的。%The use of encoders reduces the ruggedness and reliability for the vector control system of permanent magnet synchronous motor; Also, in some cases the mounting of the encoders is a major problem. In theory, speed and rotor position angle of permanent magnet synchronous motor can in real-time be calculated by voltage and current. This paper proposes a sensorless speed control strategy for a permanent magnet synchronous motor (PMSM) based on a new double sliding-mode model reference adaptive system, and the PMSM itself is selected as the reference model and its current model as the adjustable model. Two slide-mode surfaces are formulated according to two models’ output errors. Equivalent current is obtained by sliding mode, and rotor position and speed are achieved by a certain algorithm. The rotor position and speed obtained are used respectively to partake coordinate transformation and speed control in sensorless vector control of PMSM. The simulation research has been done on the basis of theoretical analysis, and shows that the proposed method is effective.
A Novel Control Approach Based on Second Order Sliding Modes & Its Application to Hydraulic Drives
Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.
2013-01-01
control accuracy to be reached. In this paper a novel control approach based on second order sliding modes utilizing the idea of the power rate reaching law is introduced. Dependent on parameters the proposed controller may preserve the main features of sliding controls, while at the same time avoiding...
Fully magnetic sliding mode control for acquiring three-axis attitude
Ovchinnikov, M. Yu.; Roldugin, D. S.; Penkov, V. I.; Tkachev, S. S.; Mashtakov, Y. V.
2016-04-01
Satellite equipped with purely magnetic attitude control system is considered. Sliding mode control is used to achieve three-axis satellite attitude. Underactuation problem is solved for transient motion. Necessary attitude is acquired by proper sliding manifold construction. Satellite motion on the manifold is executed with magnetic control system. One manifold construction approach is proposed and discussed. Numerical examples are provided.
Flexible Joints Robotic Manipulator Control By Adaptive Gain Smooth Sliding Observer-Controller
A. FILIPESCU
2003-12-01
Full Text Available An adaptive gain sliding observer for uncertain parameter nonlinear systems together with an adaptive gain sliding controller is proposed in this paper. It considered nonlinear, SISO affine systems, with uncertainties in steady-state functions and parameters. A further parameter term, adaptively updated, has been introduced in steady state space model of the controlled system, in order to obtain useful information despite fault detection and isolation. By using of the sliding observer with adaptive gain, the robustness to uncertainties is increased and the parameters adaptively updated can provide useful information in fault detection. Also, the state estimation error is bounded accordingly with bound limits of the uncertainties. The both of them, the sliding adaptive observer and sliding controller are designed to fulfill the attractiveness condition of its corresponding switching surface. An application to a single arm with flexible joint robot is presented. In order to alleviate chattering, a parameterized tangent hyperbolic has been used as switching function, instead of pure relay one, to the observer and the controller. Also, the gains of the switching functions, to the sliding observer and sliding controller are adaptively updated depending of estimation error and tracking error, respectively. By the using adaptive gains, the transient and tracking response can be improved.
Analysis of Dc/Dc converters with PWM and sliding mode controls
Static and dynamic performances of D C/D C converters with PWM and sliding mode controllers are investigated. To improve the performance of the PWM controller, a linear compensator is proposed and used. For sliding controller, important parameters such as sliding coefficients and filter time constant are carefully computed and used. Finally, a D C/D C buck converter with PWM and sliding controller is designed, modeled and constructed. Theoretical and experimental results are compared and the distinguished features and limitations of each control technique are presented
Finite time control for MIMO nonlinear system based on higher-order sliding mode.
Liu, Xiangjie; Han, Yaozhen
2014-11-01
Considering a class of MIMO uncertain nonlinear system, a novel finite time stable control algorithm is proposed based on higher-order sliding mode concept. The higher-order sliding mode control problem of MIMO nonlinear system is firstly transformed into finite time stability problem of multivariable system. Then continuous control law, which can guarantee finite time stabilization of nominal integral chain system, is employed. The second-order sliding mode is used to overcome the system uncertainties. High frequency chattering phenomenon of sliding mode is greatly weakened, and the arbitrarily fast convergence is reached. The finite time stability is proved based on the quadratic form Lyapunov function. Examples concerning the triple integral chain system with uncertainty and the hovercraft trajectory tracking are simulated respectively to verify the effectiveness and the robustness of the proposed algorithm. PMID:25277626
Implementation of Sliding Mode Observer Based Reconfiguration in an Autonomous Underwater Vehicle
A. J. Mitchell
2005-01-01
Full Text Available This paper looks at the implementation of a Sliding Mode Observer (SMO based Reconfiguration algorithm to deal with sensor faults within the context of navigation controllers for Autonomous Underwater Vehicle (AUV. In this paper the reconfigurability aspects are considered for the heading controller. Simulation responses are used to illustrate that the Sliding Mode Observer is able to give state information to the controller when there is a fault in the AUV’s sensor package. Comparisons are made between the Sliding Mode Controller with and without reconfigurability for a number of different sensor failures, e.g. bias errors in or the complete loss of the heading data, and the robustness of the Sliding Mode Observer is investigated through the introduction of disturbances into the system.
Model validation and higher order sliding mode controller design for a research reactor
Qaiser, S.H. [Center for Advanced Studies in Engineering, 19 Ataturk Avenue, Islamabad (Pakistan); Bhatti, A.I. [Mohammad Ali Jinnah University, Islamabad (Pakistan); Iqbal, Masood [Nuclear Engineering Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad (Pakistan)], E-mail: masiqbal@hotmail.com; Samar, R. [Mohammad Ali Jinnah University, Islamabad (Pakistan); Qadir, J. [Nuclear Engineering Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad (Pakistan)
2009-01-15
The paper pertains to model validation and novel higher order sliding mode controller design for a nuclear research reactor. Sliding mode controllers for nuclear reactors were reported before but higher order sliding mode controllers have added advantage of reduced chattering. As a first step of model development a simulation model of control rod drive mechanism (CRDM) has been developed using SIMULINK. This model has been validated with a lab based CRDM model, which is similar to Pakistan Research Reactor-1 (PARR-1) CRDM system. The nonlinear model of PARR-1 has been tuned and validated with experimental data. This model has been subsequently used for higher order sliding mode controller design and performance evaluation. Certain parameter values have also been recalculated to ensure model accuracy. Based on the validated model a robust nonlinear controller for controlling output power by manipulating control rod position has been developed and simulated. The new controller showed improved performance as compared to the classical PID controller.
Model validation and higher order sliding mode controller design for a research reactor
The paper pertains to model validation and novel higher order sliding mode controller design for a nuclear research reactor. Sliding mode controllers for nuclear reactors were reported before but higher order sliding mode controllers have added advantage of reduced chattering. As a first step of model development a simulation model of control rod drive mechanism (CRDM) has been developed using SIMULINK. This model has been validated with a lab based CRDM model, which is similar to Pakistan Research Reactor-1 (PARR-1) CRDM system. The nonlinear model of PARR-1 has been tuned and validated with experimental data. This model has been subsequently used for higher order sliding mode controller design and performance evaluation. Certain parameter values have also been recalculated to ensure model accuracy. Based on the validated model a robust nonlinear controller for controlling output power by manipulating control rod position has been developed and simulated. The new controller showed improved performance as compared to the classical PID controller
Chaos control of single time-scale brushless DC motor with sliding mode control method
Uyaroğlu, Yılmaz; CEVHER, Barış
2013-01-01
In this paper, the sliding mode control (SMC) scheme of single time-scale brushless DC motor (BLDCM) is investigated. The SMC method consists of 2 sections. To simplify the directive of the stability of the controlled single time-scale BLDCM in the sliding mode, first a special type of PI switching surface is adopted. Second, the SMC controller is obtained to guarantee the occurrence of the PI switching surface. The effectiveness of the theoretical analysis is evaluated by numerical...
Research of Compound Control for DC Motor System Based on Global Sliding Mode Disturbance Observer
2014-01-01
Aiming at the problems of modeling errors, parameter variations, and load moment disturbances in DC motor control system, one global sliding mode disturbance observer (GSMDO) is proposed based on the global sliding mode (GSM) control theory. The output of GSMDO is used as the disturbance compensation in control system, which can improve the robust performance of DC motor control system. Based on the designed GSMDO in inner loop, one compound controller, composed of a feedback controller and a...
Low-cost sliding mode control of WECS based on DFIG with stability analysis
DJOUDI, ABDELHAK; CHEKIREB, HACHEMI; BERKOUK, El Madjid; Bacha, Seddik
2015-01-01
The aim of this work is to developing sliding mode control of active and reactive stator powers produced by a wind energy conversion system (WECS), based on doubly fed induction generator (DFIG). A flux estimation model and rotor current sensor are no longer required. The controller is developed from the DFIG nonlinear-coupled model. Moreover, the global stability and the DFIG states' boundedness when our low-cost sliding mode control is applied are established analytically. It is reveal...
A sliding mode control for linear fractional systems with input and state delays
Si-Ammour, Amar; Djennoune, Said; Bettayeb, Maamar
2009-05-01
In this paper, a sliding mode control design for fractional order systems with input and state time-delay is proposed. First, we consider a fractional order system without delay for which a sliding surface is proposed based on fractional integration of the state. Then, a stabilizing switching controller is derived. Second, a fractional system with state delay is considered. Third, a strategy including a fractional state predictor input delay compensation is developed. The existence of the sliding mode and the stability of the proposed control design are discussed. Numerical examples are given to illustrate the theoretical developments.
The simplex method for nonlinear sliding mode control
Bartolini G.
1998-01-01
Full Text Available General nonlinear control systems described by ordinary differential equations with a prescribed sliding manifold are considered. A method of designing a feedback control law such that the state variable fulfills the sliding condition in finite time is based on the construction of a suitable simplex of vectors in the tangent space of the manifold. The convergence of the method is proved under an obtuse angle condition and a way to build the required simplex is indicated. An example of engineering interest is presented.
Frequency-shaped and observer-based discrete-time sliding mode control
Mehta, Axaykumar
2015-01-01
It is well established that the sliding mode control strategy provides an effective and robust method of controlling the deterministic system due to its well-known invariance property to a class of bounded disturbance and parameter variations. Advances in microcomputer technologies have made digital control increasingly popular among the researchers worldwide. And that led to the study of discrete-time sliding mode control design and its implementation. This brief presents, a method for multi-rate frequency shaped sliding mode controller design based on switching and non-switching type of reaching law. In this approach, the frequency dependent compensator dynamics are introduced through a frequency-shaped sliding surface by assigning frequency dependent weighing matrices in a linear quadratic regulator (LQR) design procedure. In this way, the undesired high frequency dynamics or certain frequency disturbance can be eliminated. The states are implicitly obtained by measuring the output at a faster rate than th...
Universal fuzzy integral sliding-mode controllers for stochastic nonlinear systems.
Gao, Qing; Liu, Lu; Feng, Gang; Wang, Yong
2014-12-01
In this paper, the universal integral sliding-mode controller problem for the general stochastic nonlinear systems modeled by Itô type stochastic differential equations is investigated. One of the main contributions is that a novel dynamic integral sliding mode control (DISMC) scheme is developed for stochastic nonlinear systems based on their stochastic T-S fuzzy approximation models. The key advantage of the proposed DISMC scheme is that two very restrictive assumptions in most existing ISMC approaches to stochastic fuzzy systems have been removed. Based on the stochastic Lyapunov theory, it is shown that the closed-loop control system trajectories are kept on the integral sliding surface almost surely since the initial time, and moreover, the stochastic stability of the sliding motion can be guaranteed in terms of linear matrix inequalities. Another main contribution is that the results of universal fuzzy integral sliding-mode controllers for two classes of stochastic nonlinear systems, along with constructive procedures to obtain the universal fuzzy integral sliding-mode controllers, are provided, respectively. Simulation results from an inverted pendulum example are presented to illustrate the advantages and effectiveness of the proposed approaches. PMID:24718584
Shahnaz Tayebi Haghighi
2013-05-01
Full Text Available Design a nonlinear controller for second order nonlinear uncertain dynamical systems (e.g., internal combustion engine is one of the most important challenging works. This paper focuses on the comparative study between two important nonlinear controllers namely; computed torque controller (CTC and sliding mode controller (SMC and applied to internal combustion (IC engine in presence of uncertainties. In order to provide high performance nonlinear methodology, sliding mode controller and computed torque controller are selected. Pure SMC and CTC can be used to control of partly known nonlinear dynamic parameters of IC engine. Pure sliding mode controller and computed torque controller have difficulty in handling unstructured model uncertainties. To solve this problem applied linear error-based tuning method to sliding mode controller and computed torque controller for adjusting the sliding surface gain (λ and linear inner loop gain (K. Since the sliding surface gain (λ and linear inner loop gain (K are adjusted by linear error-based tuning method. In this research new λ and new K are obtained by the previous λ and K multiple gains updating factor(α. The results demonstrate that the error-based linear SMC and CTC are model-based controllers which works well in certain and uncertain system. These controllers have acceptable performance in presence of uncertainty.
Composite Sliding Mode Control for a Free-Floating Space Rigid-Flexible Coupling Manipulator System
Wang Congqing
2013-02-01
Full Text Available The flexible space manipulator is a highly nonlinear and coupled dynamic system. This paper proposes a novel composite sliding mode control to deal with the vibration suppression and trajectory tracking of a free‐floating space rigid‐flexible coupling manipulator with a rigid payload. First, the dynamic equations of this system are established by using Lagrange and assumed mode methods and in the meantime this dynamic modelling allows consideration of the modelling errors, the external disturbance and the vibration damping of a flexible link. Then, in modal space, the problems of the manipulator system’s trajectory tracking and the vibration suppression are discussed by using the composite control approach, which combines a non‐ singular terminal sliding mode control (NTSMC with an active vibration suppression control (AVSC. The NTSMC uses a fuzzy logic outputinstead ofthe symbol item, which smoothes the control signal, thereby inhibiting the chattering of the sliding mode control. Compared with common sliding mode control (SMC, the approach not only can reduce the chattering of the sliding mode control, but also can eliminate the singular phenomenon of the system’s control input. In addition, it can assure the trajectory tracking and the vibration suppression. Many space missions can benefit from this modelling system, such as autonomous docking of satellites, rescuing and satellite servicing. Finally, the numerical simulations were carried out, which confirmed the effectiveness of these methods.
Chaos Control in Memristor-based Oscillators Using Intelligent Sliding Mode Control
Amir Hossein Abolmasoumi
2014-10-01
Full Text Available In this paper, Intelligent Sliding Mode Control of chaos in a memristor- based Chua’s oscillator is investigated. In order to gain stabilization and tracking of a sinusoidal input, an appropriate sliding surface is proposed and sliding gain is tuned. Also, to avoid the chattering phenomenon in traditional sliding mode controller, and to reduce the hitting time of the controlled system, an especial genetic algorithm optimization method is suggested. By defining a new objective function and searching for optimal the controller parameters the convergence time and chattering are reduced considerably. The usefulness of the proposed controller with intelligent tuning method for chaos control of memristorbased oscillators is demonstrated in memristor- based Chua's circuit.
Analysis and Experimental Study of Proportional-Integral Sliding Mode Control for DC/DC Converter
ZHANG Li; QIU Shui-sheng
2005-01-01
DC/DC converter using the proportional-integral (PI) sliding mode control (SMC) scheme is investigated, including the selection of the switching surface, the proof of the reaching condition and the existence condition of sliding motion. The sliding regime and the local stability are given. The implementation of the PI SMC is simpler than other SMC schemes and the steady-state error is eliminated. A prototype based on Buck converter is built up. The experimental results show that the dynamic performance and robustness to the parameter variations and external disturbances are improved.
Output Feedback and Single-Phase Sliding Mode Control for Complex Interconnected Systems
Yao-Wen Tsai; Huynh, Van Van
2015-01-01
This paper generalized a new sliding mode control (SMC) without reaching phase to solve two important problems in the stability of complex interconnected systems: (1) a decentralized controller that uses only output variables directly and (2) the stability of complex interconnected systems ensured for all time. A new sliding surface is firstly designed to construct a single-phase SMC in which the desired motion is determined from the initial time instant. A new lemma is secondly established f...
Development of a Novel Fractional Order Sliding Mode Controller for a Gun
Qiang Gao; Haijun Chen; Guolai Yang; Jilin Chen; Yuanlong Hou
2013-01-01
To solve the nonlinearity phenomenon of a Gun Control System (GCS), a novel Fractional order Sliding Mode Control (FoSMC) strategy is proposed in this study. By inducing the fractional order calculus, a Fractional Order PID (FOPID) type sliding surface is especially designed and consequently an equivalent control discipline with fractional order dynamics is induced. The saturation function is employed as the switch function. By numerical simulation, the dynamic characteristics of the FoSMC ba...
Coker, D; Needleman, A; Rosakis, A J
2004-01-01
Frictional sliding along an interface between two identical isotropic elastic plates under impact shear loading is investigated experimentally and numerically. The plates are held together by a compressive stress and one plate is subject to edge impact near the interface. The experiments exhibit both a crack-like and a pulse-like mode of sliding. Plane stress finite element calculations modeling the experimental configuration are carried out, with the interface characterized by a rate and state dependent frictional law. For low values of the initial compressive stress and impact velocity, sliding occurs in a crack-like mode. For higher values of the initial compressive stress and/or impact velocity, sliding takes place in a pulse-like mode. A variety of sliding modes are obtained in the calculations depending on the impact velocity, the initial compressive stress and the values of interface variables. One pulse-like mode involves well-separated pulses with the pulse amplitude increasing with propagation dista...
Benbouzid, Mohamed; Beltran, Brice; Amirat, Yassine; Yao, Gang; Han, Jingang; Mangel, Hervé
2014-05-01
This paper deals with the fault ride-through capability assessment of a doubly fed induction generator-based wind turbine using a high-order sliding mode control. Indeed, it has been recently suggested that sliding mode control is a solution of choice to the fault ride-through problem. In this context, this paper proposes a second-order sliding mode as an improved solution that handle the classical sliding mode chattering problem. Indeed, the main and attractive features of high-order sliding modes are robustness against external disturbances, the grids faults in particular, and chattering-free behavior (no extra mechanical stress on the wind turbine drive train). Simulations using the NREL FAST code on a 1.5-MW wind turbine are carried out to evaluate ride-through performance of the proposed high-order sliding mode control strategy in case of grid frequency variations and unbalanced voltage sags. PMID:24530194
Benchabane, Fateh; Titaouine, Abdenacer; Bennis, Ouafae; Yahia, Khaled; Taibi, Djamel
2012-01-01
In this paper a systematic fuzzy sliding mode controller is presented for permanent magnet synchronous motor (PMSM) sensorless drives. The fuzzy sliding mode controller is designed based on input-output feedback linearization control technique. The extended Kalman filter is used to estimate the speed, position and load torque. The PMSM is fed from indirect power electronics converter. This indirect converter is controlled by the sliding mode technique. This control technique allows the minimi...
Sliding mode control of photoelectric tracking platform based on the inverse system method
Yao Zong Chen
2016-01-01
Full Text Available In order to improve the photoelectric tracking platform tracking performance, an integral sliding mode control strategy based on inverse system decoupling method is proposed. The electromechanical dynamic model is established based on multi-body system theory and Newton-Euler method. The coupled multi-input multi-output (MIMO nonlinear system is transformed into two pseudo-linear single-input single-output (SISO subsystems based on the inverse system method. An integral sliding mode control scheme is designed for the decoupled pseudo-linear system. In order to eliminate system chattering phenomenon caused by traditional sign function in sliding-mode controller, the sign function is replaced by the Sigmoid function. Simulation results show that the proposed decoupling method and the control strategy can restrain the influences of internal coupling and disturbance effectively, and has better robustness and higher tracking accuracy.
Wei Jianhua; Guan Cheng
2005-01-01
The velocity tracking control of a hydraulic servo system is studied. Since the dynamics of the system are highly nonlinear and have large extent of model uncertainties, such as big changes in load and parameters, a derivation and integral sliding mode variable structure control scheme (DI-SVSC) is proposed. An integral controller is introduced to avoid the assumption that the derivative of desired signal must be known in conventional sliding mode variable structure control, a nonlinear derivation controller is used to weaken the chattering of system. The design method of switching function in integral sliding mode control, nonlinear derivation coefficient and controllers of DI-SVSC is presented respectively. Simulation shows that the control approach is of nice robustness and improves velocity tracking accuracy considerably.
Decoupled thermal control for space station furnace facility using sliding mode techniques
Jackson, Mark E.; Shtessel, Yuri B.
1996-03-01
The Space Station Furnace Facility (SSFF) provides the necessary core systems to operate various material processing furnaces. The Thermal Control System (TCS) is defined as one of the core systems and its function is to collect excess heat from furnaces and to provide precise cold temperature control of components and of certain furnace zones. Physical interconnection of parallel thermal control subsystems through a common pump implies the description of the whole TCS by coupled nonlinear differential equations in flow and pressure. The paper formulates the system equations and develops the sliding mode controllers that cause the interconnected subsystems to operate in the local sliding modes, resulting in control system invariance to interaction disturbances. The desired de-coupled flow rate profile tracking is achieved by optimization of the local linear sliding mode equations. Extensive digital simulation results are presented to show the flow rate tracking robustness and invariance to plant nonlinearities and variations of the pump pressure supplied to the controlled subsystems.
Sliding mode control for multi-agent systems under a time-varying topology
Dong, Lijing; Chai, Senchun; Zhang, Baihai; Kiong Nguang, Sing
2016-07-01
This paper addresses the tracking problem of a class of multi-agent systems under uncertain communication environments which has been modelled by a finite number of constant Laplacian matrices together with their corresponding scheduling functions. Sliding mode control method is applied to solve this nonlinear tracking problem under a time-varying topology. The controller of each tracking agent has been designed by using only its own and neighbours' information. Sufficient conditions for the existence of a sliding mode control tracking strategy have been provided by the solvability of linear matrix inequalities. At the end of this work, numerical simulations are employed to demonstrate the effectiveness of the proposed sliding mode control tracking strategy.
High order sliding mode control of a DFIM supplied by two power inverters
Zinelaabidine Boudjema
2015-06-01
Full Text Available Traditional vector control structures which include proportional-integral (PI regulator for the speed of a doubly fed induction motor (DFIM driven have some disadvantages such as parameter tuning complications, mediocre dynamic performances and reduced robustness. Thus, based on the analysis of the mathematical model of a DFIM supplied by two indirect inverters, this paper addresses a nonlinear control algorithm based on high order sliding mode. The conventional sliding mode control has large chattering on the electromagnetic torque developed by the DFIM. In order to solve this problem, the second order sliding mode technique is used. The simulation results show the effectiveness of the proposed method especially in chattering-free behavior, response to sudden load torque variations and robustness against machine parameters variations.
Trajectory Tracking of Linear Inverted Pendulum Using Integral Sliding Mode Control
Punitkumar Bhavsar
2012-06-01
Full Text Available This paper considers the trajectory tracking control of linear inverted pendulum (IP system. First the linearized model of IP is derived to facilitate the control design. To avoid non robust reaching phase, integral sliding mode control (ISMC has been proposed but single variable case is tested. Linear IP is a multivariable system having angle of pendulum and position of cart are two variables to be controlled. In control design, the LQR control is designed as a nominal control to get the desired trajectory. Then discontinuous control using integral sliding mode(ISM is introduced to get desired trajectory tracking in the presence of uncertainties. This control is robust to the model uncertainties and disturbances during entire motion of the states. The simulation results are presented to show the effectiveness of proposed control scheme. The results are compared with LQR control to show the integral sliding mode control is having better tracking performance in the presence of uncertainties.
Power Control of Wind Turbine Based on Fuzzy Sliding-Mode Control
Tahir Khalfallah
2015-02-01
Full Text Available This paper presents the study of a variable speed wind energy conversion system (WECS using a Wound Field Synchronous Generator (WFSG based on a Fuzzy sliding mode control (FSMC applied to achieve control of active and reactive powers exchanged between the stator of the WFSG and the grid to ensure a Maximum Power Point Tracking (MPPT of a wind energy conversion system. However the principal drawback of the sliding mode, is the chattering effect which characterized by torque ripple, this phenomena is undesirable and harmful for the machines, it generates noises and additional forces of torsion on the machine shaft. A direct fuzzy logic controller is designed and the sliding mode controller is added to compensate the fuzzy approximation errors. The simulation results clearly indicate the effectiveness and validity of the proposed method, in terms of convergence, time and precision.
Chattering-free fuzzy sliding-mode control strategy for uncertain chaotic systems
This paper proposes a chattering-free fuzzy sliding-mode control (FSMC) strategy for uncertain chaotic systems. A fuzzy logic control is used to replace the discontinuous sign function of the reaching law in traditional sliding-mode control (SMC), and hence a control input without chattering is obtained in the chaotic systems with uncertainties. Base on the Lyapunov stability theory, we address the design schemes of integration fuzzy sliding-mode control, where the reaching law is proposed by a set of linguistic rules and the control input is chattering free. The Genesio chaotic system is used to test the proposed control strategy and the simulation results show the FSMC not only can control the uncertain chaotic behaviors to a desired state without oscillator very fast, but also the switching function is smooth without chattering. This result implies that this strategy is feasible and effective for chaos control
Meng-Hui Wang
2015-08-01
Full Text Available Sliding mode strategy (SMS for maximum power point tracking (MPPT is used in this study of a human power generation system. This approach ensures maximum power at different rotation speeds to increase efficiency and corrects for the lack of robustness in traditional methods. The intelligent extension theory is used to reduce input saturation and high frequency switching in sliding mode strategy, as well as to increase the efficiency and response speed. The experimental results show that the efficiency of the extension SMS (ESMS is 5% higher than in traditional SMS, and the response is 0.5 s faster.
Variable structure control with sliding mode prediction for discrete-time nonlinear systems
Lingfei XIAO; Hongye SU; Xiaoyu ZHANG; Jian CHU
2006-01-01
A new variable structure control algorithm based on sliding mode prediction for a class of discrete-time nonlinear systems is presented. By employing a special model to predict future sliding mode value, and combining feedback correction and receding horizon optimization methods which are extensively applied on predictive control strategy, a discrete-time variable structure control law is constructed. The closed-loop systems are proved to have robustness to uncertainties with unspecified boundaries. Numerical simulation and pendulum experiment results illustrate that the closed-loop systems possess desired performance, such as strong robustness, fast convergence and chattering elimination.
High Order Sliding Mode Control of Doubly-fed Induction Generator under Unbalanced Grid Faults
Zhu, Rongwu; Chen, Zhe; Wu, Xiaojie; Liu, Hongzhi
This paper deals with a doubly-fed induction generator-based (DFIG) wind turbine system under grid fault conditions such as: unbalanced grid voltage, three-phase grid fault, using a high order sliding mode control (SMC). A second order sliding mode controller, which is robust with respect to......) control. In order to improve control performance of the overall system, electromagnetic power and active power oscillations elimination strategies are proposed respectively. Lastly, the effective of the proposed control strategy is verified by the simulation results of a 2 MW DFIG system....
Unknown Input and Sensor Fault Estimation Using Sliding-Mode Observers
Kalsi, Karanjit; Hui, Stefen; Zak, Stanislaw
2011-06-29
Sliding-mode observers are used to construct unknown input estimators. Then, these unknown input estimators are combined with sensor fault estimation schemes into one architecture that employs two sliding-mode observers for simultaneously estimating the plant’s actuator faults (part of the unknown input) and detecting sensor faults. Closed form expressions are presented for the estimates of unknown inputs and sensor faults. A benchmark example of a controlled inverted pendulum system from the literature is utilized in the simulation study. The study shows that the observers analyzed in this paper generate good estimates of the unknown input and sensor faults signals in noisy environments for nonlinear plants.
Stabilizing sliding mode control design and application for a dc motor: Speed control
Rhif, Ahmed
2012-01-01
The regulation by sliding mode control (SMC) is recognized for its qualities of robustness and dynamic response. This article will briefly talk about the regulation principles by sliding mode as well as the application of this approach to the adjustment of a speed control DC motor bench using the TY36A/EV unit. This unit, from Electronica Veneta products, uses a PID controller to control the speed and position of the DC motor. Our purpose is to improve the set time answer and the robustness o...
Finite-Time Reentry Attitude Control Using Time-Varying Sliding Mode and Disturbance Observer
Xuzhong Wu
2015-01-01
Full Text Available This paper presents the finite-time attitude control problem for reentry vehicle with redundant actuators in consideration of planet uncertainties and external disturbances. Firstly, feedback linearization technique is used to cancel the nonlinearities of equations of motion to construct a basic mode for attitude controller. Secondly, two kinds of time-varying sliding mode control methods with disturbance observer are integrated with the basic mode in order to enhance the control performance and system robustness. One method is designed based on boundary layer technique and the other is a novel second-order sliding model control method. The finite-time stability analyses of both resultant closed-loop systems are carried out. Furthermore, after attitude controller produces the torque commands, an optimization control allocation approach is introduced to allocate them into aerodynamic surface deflections and on-off reaction control system thrusts. Finally, the numerical simulation results demonstrate that both of the time-varying sliding mode control methods are robust to uncertainties and disturbances without chattering phenomenon. Moreover, the proposed second-order sliding mode control method possesses better control accuracy.
Design of practical sliding-mode controllers with constant switching frequency for power converters
Navarro-Lopez, Eva M. [School of Computer Science, Centre for Interdisciplinary Computational and Dynamical Analysis, The University of Manchester, Oxford Road, Kilburn Building, Manchester M13 9PL (United Kingdom); Cortes, Domingo [Seccion de Mecatronica, Departamento de Ingenieria Electrica, CINVESTAV-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360 Mexico City (Mexico); Castro, Christian [Centro de Investigacion en Computacion del IPN, Av. Jose Othon de Mendizabal s/n, Col. Nueva Industrial Vallejo, 07738 Mexico City (Mexico)
2009-05-15
A novel experimentally motivated method in order to design a family of easy-to-implement sliding-mode controllers for power converters is proposed. Two main results are presented. First, the relation between sliding-mode control and average control is reinterpreted so that the limitation of the switching frequency for the closed-loop system is achieved in a more direct way than other methods so far reported in the literature. For this purpose, a class of sliding surfaces which makes the associated equivalent control be the system average control is proposed. Second, the achievement of a constant switching frequency in the controlled system is assured without requiring the sliding-mode-based controller to be modified, unlike most previous works. As a result, the proposed sliding surfaces-type can be directly implemented via a pulse-width modulator. The control methodology is implemented for the voltage control in a boost converter prototype in which the load is considered unknown. Experimental results confirm high performance and robustness under parameters variation. Furthermore, the solution proposed is easy to implement and well-suited for other power converters. (author)
Development of a Novel Fractional Order Sliding Mode Controller for a Gun
Qiang Gao
2013-09-01
Full Text Available To solve the nonlinearity phenomenon of a Gun Control System (GCS, a novel Fractional order Sliding Mode Control (FoSMC strategy is proposed in this study. By inducing the fractional order calculus, a Fractional Order PID (FOPID type sliding surface is especially designed and consequently an equivalent control discipline with fractional order dynamics is induced. The saturation function is employed as the switch function. By numerical simulation, the dynamic characteristics of the FoSMC based control system are analyzed and compared with Conventional Sliding Mode Control (CSMC system. The results demonstrate that the FoSMC system could reach up to the equilibrium state more smoothly, which shall significantly suppress the inherent chatter effects. Besides, the FoSMC based gun control system is of high response rate, better positioning accuracy and high robustness, which is suitable for fast, smooth and accurate adjustments of the gun.
A novel sliding mode nonlinear proportional-integral control scheme for controlling chaos
Yu Dong-Chuan; Wu Ai-Guo; Yang Chao-Ping
2005-01-01
A novel sliding mode nonlinear proportional-integral control (SMNPIC) scheme is proposed for driving a class of time-variant chaotic systems with uncertainty to arbitrarily desired trajectory with high accuracy. The SMNPIC differs from the previous sliding mode techniques in the sense that a nonlinear proportional-integral action of sliding function is involved in control law, so that both the steady-state error and the high-frequency chattering are reduced,and meanwhile, robustness and fastness are guaranteed. In addition, the proposed SMNPIC actually acts as a class of nonlinear proportional-integral-differential (PID) controller, in which the tracking error and its derivatives up to (n-1)thorder as well as the integral of tracking error are considered, so that more useful information than traditional PID can be implemented and better dynamic and static characteristics can obtained. Its good performance for chaotic control is illustrated through a During-Holmes system with uncertainty.
Li-lian Huang
2013-01-01
Full Text Available The synchronization of nonlinear uncertain chaotic systems is investigated. We propose a sliding mode state observer scheme which combines the sliding mode control with observer theory and apply it into the uncertain chaotic system with unknown parameters and bounded interference. Based on Lyapunov stability theory, the constraints of synchronization and proof are given. This method not only can realize the synchronization of chaotic systems, but also identify the unknown parameters and obtain the correct parameter estimation. Otherwise, the synchronization of chaotic systems with unknown parameters and bounded external disturbances is robust by the design of the sliding surface. Finally, numerical simulations on Liu chaotic system with unknown parameters and disturbances are carried out. Simulation results show that this synchronization and parameter identification has been totally achieved and the effectiveness is verified very well.
张强; 于宏亮; 许德智; 于美娟
2016-01-01
针对一类不确定非线性系统的跟踪控制问题,在考虑建模误差、参数不确定和外部干扰情况下,以良好的跟踪性能及强鲁棒性为目标,提出基于自组织小脑模型(self-organizing wavelet cerebellar model articulation controller, SOWCMAC)的鲁棒自适应积分末端(terminal)滑模控制策略。首先,将小脑模型、自组织神经网络和小波函数各自优势相结合,给出一种SOWCMAC,以保证干扰估计方法具有快速学习能力和更好的泛化能力。其次,设计两种改进的terminal滑模面构造方法,并分别给出各自的收敛时间。然后,基于SOWCMAC和改进的积分terminal滑模面,给出不确定非线性系统鲁棒自适应非奇异terminal控制器的设计过程,其中通过构造自适应鲁棒项抑制干扰估计误差对系统跟踪性能的影响,并利用Lyapunov理论证明闭环系统的稳定性。最后,将该方法应用于近空间飞行器姿态的控制仿真实验,结果表明所提出方法有效性。%We propose a robust adaptive integral terminal sliding mode control method using self-organizing wavelet cerebella model articulation controller (SOWCMAC) for a class of uncertain nonlinear systems with modeling error, parameter uncertainty and external disturbances to achieve the desired tracking performance and strong robustness. Firstly, we make use of the advantages of cerebella model articulation controller, self-organizing neural networks and wavelet function in developing the SOWCMAC to ensure the fast learning ability and desirable generalization ability. Next, we design two kinds of improved integral terminal sliding surfaces and express their convergence time in the analytical form. With the SOWCMAC and improved integral terminal sliding surfaces, we develop the robust adaptive nonsingular terminal controller for the uncertain nonlinear systems. The adaptive robust term can offset the impact of the approximation errors for the system. The stability of
ERBATUR, Kemalettin; Çallı, Berk; Calli, Berk
2008-01-01
Chattering in the control signal is a significant problem in sliding mode control (SMC). The boundary layer approach is one of the many modifications proposed in the literature to avoid the chattering. In this approach, instead of the discontinuous sliding mode control, a continuous feedback control law is employed in a boundary layer around the sliding surface. The thickness of the boundary layer is an important design parameter. This paper proposes a fuzzy online tuning method to adjust the...
Synchronizing Spatiotemporal Chaos via a Composite Disturbance Observer-Based Sliding Mode Control
Congyan Chen
2014-01-01
Full Text Available The sliding mode control schemes are investigated to synchronize two spatiotemporal chaotic systems, which are two arrays of a large number of coupled chaotic oscillators. Firstly, sliding mode manifolds with the desired performance are designed. The asymptotic convergence to the origin of the synchronization errors is also proved. However, the terms from parameter fluctuations in equivalent controls are usually impossible to be measured directly. So we regard them as lumped disturbances, but, for practical application, it is difficult to obtain the upper bound of lumped disturbances in advance which often results in a conservative sliding mode control law with large control effort, causing a large amount of chattering. To reduce the chattering and improve the performance of the system, a disturbance observer is designed to estimate the lumped disturbances. A composite synchronization controller that consists of a sliding mode feedback part and a feedforward compensation part based on disturbance observer is developed. The numerical simulation results are presented to show the effectiveness of the proposed methods.
Decoupled Sliding Mode Control for a Novel 3-DOF Parallel Manipulator with Actuation Redundancy
Niu Xuemei
2015-05-01
Full Text Available This paper presents a decoupled nonsingular terminal sliding mode controller (DNTSMC for a novel 3-DOF parallel manipulator with actuation redundancy. According to kinematic analysis, the inverse dynamic model for a novel 3-DOF redundantly actuated parallel manipulator is formulated in the task space using Lagrangian formalism and decoupled into three entirely independent subsystems under generalized coordinates to significantly reduce system complexity. Based on the dynamic model, a decoupled sliding mode control strategy is proposed for the parallel manipulator; the idea behind this strategy is to design a nonsingular terminal sliding mode controller for each subsystem, which can drive states of three subsystems to the original equilibrium points simultaneously by two intermediate variables. Additionally, a RBF neural network is used to compensate the cross-coupling force and gravity to enhance the control precision. Simulation and experimental results show that the proposed DNTSMC can achieve better control performances compared with the conventional sliding mode controller (SMC and the DNTSMC without compensator.
Design of passive fault-tolerant controllers of a quadrotor based on sliding mode theory
Merheb Abdel-Razzak
2015-09-01
Full Text Available Abstract In this paper, sliding mode control is used to develop two passive fault tolerant controllers for an AscTec Pelican UAV quadrotor. In the first approach, a regular sliding mode controller (SMC augmented with an integrator uses the robustness property of variable structure control to tolerate partial actuator faults. The second approach is a cascaded sliding mode controller with an inner and outer SMC loops. In this configuration, faults are tolerated in the fast inner loop controlling the velocity system. Tuning the controllers to find the optimal values of the sliding mode controller gains is made using the ecological systems algorithm (ESA, a biologically inspired stochastic search algorithm based on the natural equilibrium of animal species. The controllers are tested using SIMULINK in the presence of two different types of actuator faults, partial loss of motor power affecting all the motors at once, and partial loss of motor speed. Results of the quadrotor following a continuous path demonstrated the effectiveness of the controllers, which are able to tolerate a significant number of actuator faults despite the lack of hardware redundancy in the quadrotor system. Tuning the controller using a faulty system improves further its ability to afford more severe faults. Simulation results show that passive schemes reserve their important role in fault tolerant control and are complementary to active techniques
Stoyan Tzonkov
2005-04-01
Full Text Available An implementation of sliding mode control for yeast fed-batch cultivation is presented in this paper. Developed controller has been implemented on two real fed-batch cultivations of Saccharomyces cerevisiae. The controller successfully stabilizes the process and shows a very good performance at high input disturbances.
Designing of Proportional Sliding Mode Controller for Linear One Stage Inverted Pendulum
Anirban Banrejee
2011-01-01
Full Text Available The control of Inverted Pendulum (IP is a hugely complex task. A great deal of nonlinearity is present inherently and as well as affected by the surrounding external conditions. The sliding mode controller (SMC is very robust inherently. It is used in this paper to control the IP. This paper examines the designing of sliding mode controller (SMC for a linear inverted pendulum (IP. The paper highlights the important features of the sliding mode and also throws ample lights on the designing guidelines. The paper puts special impetus on the mathematical modeling of the controller. The robustness of the design of SMC with proportional control is amply displayed with the help of simple mathematics. It gives rise to a controller which can control a highly nonlinear system like IP quite efficiently. The performance of the SMC is compared with fuzzy and PID controller. The edge this controller poses is the key aspect of this paper. External disturbances and internal inaccuracies are also introduced to the system to bring out the robustness of the controller to the fore. Background on sliding mode and the pendulum are provided. Simulation results are displayed in a vivid manner and explained suitably.
Sliding Modes after the First Decade of the 21st Century State of the Art
Moreno, Jaime; Iriarte, Rafael
2012-01-01
The book presents the newest results of the major world research groups working in the area of Variable Structure Systems and Sliding Mode Control (VSS/SMC). The research activity of these groups is coordinated by the IEEE Technical Committee on Variable Structure Systems (VSS) and Sliding Modes (SM). The presented results include the reports of the research groups collaborating in a framework of the Unión European Union – México project of Fondo de Cooperación Internacional en Ciencia y Tecnología (FONCICyT) 93302 titled "Automatization and Monitoring of Energy Production Processes via Sliding Mode Control". The book starts with the overview of the sliding mode control concepts and algorithms that were developed and discussed in the last two decades The research papers are combined in three sections: Part I: VSS and SM Algorithms and their Analysis Part II: SMC Design Part III: Applications of VSS and SMC The book will be of interests of engineers, researchers and graduate students working in the area ...
Super-twisting sliding mode direct torque contol of induction machine drives
Lascu, Cristian; Blaabjerg, Frede
2014-01-01
This paper presents a new super-twisting sliding modes direct torque and flux controller (STSM-DTC) for induction motor (IM) drives. The STSM is a second-order (type two) variable-structure control which operates without high-frequency chattering. The proposed STSM scheme is a torque and stator...
The paper pertains to novel higher order sliding mode observer (SMO) design for estimating precursor concentration of a nuclear research reactor. The linear and nonlinear models of Pakistan Research Reactor-1 (PARR-1) have been tuned and validated with experimental data. These models are subsequently used for higher order sliding mode observer design and performance evaluation. In thermal reactors, precursor concentration is a very important reactor variable because it is responsible for delayed neutron production and finally for reactor control. Linear observers have been used in the past to estimate precursor concentration, but the bandwidth is much limited and performance degraded as the operating point is changed. The nonlinear observer can cater for this problem in a much efficient manner. In this paper a robust nonlinear observer for estimating precursor concentration has been developed by using second order sliding mode technique. The higher order sliding mode observer is efficient and has the main advantage of reduced chattering. The observer estimates the precursor concentration with the measurement of neutron flux only and the estimated value is in close agreement with the theoretically calculated value.
Sliding-Mode Observer for Speed and Position Sensorless Control of Linear-PMSM
Kazraji Saeed Masoumi
2014-05-01
Full Text Available The paper presents a sliding-mode observer that utilizes sigmoid function for speed and position sensorless control of permanent-magnet linear synchronous motor (PMLSM. In conventional sliding mode observer method there are the chattering phenomenon and the phase lag. Thus, in order to avoid the usage of the low pass filter and the phase compensator based on back EMF, in this paper a sliding mode observer with sigmoid function for detecting the back EMF in a PMLSM is designed to estimate the speed and the position of the rotor. Most of conventional sliding mode observers use sign or saturation functions which need low pass filter in order to detect back electromotive force (back EMF. In this paper a sigmoid function is used instead of discontinuous sign function to decrease undesirable chattering phenomenon. By reducing the chattering, detecting of the back EMF can be made directly from switching signal without any low pass filter. Thus the delay time in the proposed observer is eliminated because of the low pass filter. Furthermore, there is no need to compensate phase fault in position and speed estimating of linear-PMSM. Advantages of the proposed observer have been shown by simulation with MATLAB software.
Sliding Mode Control of PMSG Wind Turbine Based on Enhanced Exponential Reaching Law
2016-01-01
This paper proposes a Sliding Mode Control (SMC) based scheme for a variable speed, direct-driven Wind Energy Conversion Systems (WECS) equipped with Permanent Magnet Synchronous Generator (PMSG) connected to the grid. In this work, diode rectifier, boost converter, Neutral Point Clamped (NPC) in...
Asymptotic Stability for Coupled Modal Sliding Mode Control of Vibration in a Flexible Structure
Ming-Chang Pai
2009-01-01
Full Text Available This paper deals with the asymptotic stability of the coupled modal sliding mode control of a vibratory structure in the presence of parametric uncertainties. The method is based on the linear fractional transformation and the small gain theorem / μ analysis. Using a flexible tetrahedral truss structure, a numerical example is presented to verify the theoretical analysis.
Energy-Saving Sliding Mode Control for Synchronous Drive Fed by Renewable Energy Source
Ryvkin, S.; Chomát, Miroslav
Side: TU Side, 2015, s. 582-587. ISBN 978-1-4673-7239-8. [ACEMP-OPTIM-ELECTROMOTION 2015. Side (TR), 02.09.2015-04.09.2015] Institutional support: RVO:61388998 Keywords : energy efficiency * renewable energy variability * sliding mode control Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
Qaiser, S. Hameed [Center for Advanced Studies in Engineering (CASE), 19, Ataturk Avenue G-5/1, Islamabad (Pakistan)], E-mail: h_qaiser@yahoo.com; Bhatti, Aamer Iqbal [Mohammad Ali Jinnah University (MAJU), Islamabad (Pakistan); Iqbal, Masood [Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan); Samar, Raza [Mohammad Ali Jinnah University (MAJU), Islamabad (Pakistan); Qadir, Javed [Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan)
2009-10-15
The paper pertains to novel higher order sliding mode observer (SMO) design for estimating precursor concentration of a nuclear research reactor. The linear and nonlinear models of Pakistan Research Reactor-1 (PARR-1) have been tuned and validated with experimental data. These models are subsequently used for higher order sliding mode observer design and performance evaluation. In thermal reactors, precursor concentration is a very important reactor variable because it is responsible for delayed neutron production and finally for reactor control. Linear observers have been used in the past to estimate precursor concentration, but the bandwidth is much limited and performance degraded as the operating point is changed. The nonlinear observer can cater for this problem in a much efficient manner. In this paper a robust nonlinear observer for estimating precursor concentration has been developed by using second order sliding mode technique. The higher order sliding mode observer is efficient and has the main advantage of reduced chattering. The observer estimates the precursor concentration with the measurement of neutron flux only and the estimated value is in close agreement with the theoretically calculated value.
Super Twisting Second Order Sliding Mode Control for Position Tracking Control of Hydraulic Drives
Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.;
2013-01-01
In this paper a control strategy based on second order sliding modes, generally applicable for position tracking control of electro-hydraulic valve-cylinder drives (VCD), is proposed. The main target is to overcome problems with linear controllers deteriorating performance due to the strong...
Lascu, Christian; Boldea, Ion; Blaabjerg, Frede
2013-01-01
This paper investigates a permanent magnet synchronous motor drive controlled by a second-order variable structure control technique, known as the super-twisting sliding modes (STSM) control. The STSM controller is designed as a direct torque and flux controller and it works in the stator flux...
Design Intelligent PID like Fuzzy Sliding Mode Controller for Spherical Motor
Farzin Matin
2014-04-01
Full Text Available The minimum rule base Proportional Integral Derivative (PID Fuzzy Sliding Mode Controller (SMC with application to spherical motor is presented in this research. The popularity of PID Fuzzy Sliding Mode Controller can be attributed to their robust performance in a wide range of operating conditions and partly to their functional simplicity. The process of setting of PID Fuzzy Sliding Mode Controller can be determined as an optimization task. Over the years, use of intelligent strategies for tuning of these controllers has been growing especially in nonlinear and uncertain systems. Proportional Integral Derivative methodology has three inputs and if any input is described with seven linguistic values, and any rule has three conditions, we will need 343 rules. It is too much work to write 343 rules and have lots of problem to design embedded control system e.g., Field Programmable Gate Array (FPGA. In this research the PID-like fuzzy controller can be constructed as a parallel structure of a PD-like fuzzy controller and a conventional PI controller to have the minimum rule base and good trajectory follow disturbance to control of spherical motor. However Sliding Mode Controller is work based on cancelling decoupling and nonlinear terms of dynamic parameters for each direction of three degree of freedom spherical motor, this controller is work based on motor dynamic model and this technique is highly sensitive to the knowledge of all parameters of nonlinear spherical motor’s dynamic equation which caused to challenge in uncertain system. This research is used to reduce or eliminate the Sliding Mode Controller problem based on minimum rule base fuzzy logic theory to control of three degrees of freedom spherical motor system and testing of the quality of process control in the simulation environment of MATLAB/SIMULINK Simulator.
Power Efficient Higher Order Sliding Mode Control of SR Motor for Speed Control Applications
Muhammad Rafiq
2011-05-01
Full Text Available This paper presents a novel scheme for speed regulation/tracking of Switched Reluctance (SR motors based on Higher-Order Sliding-Mode technique. In particular, a Second-Order Sliding-Mode Controller (SOSMC based on Super Twisting algorithm is devel-oped. Owing to the peculiar structural properties of SRM, torque produced by each motor phase is a function of phase current as well as rotor position. More importantly, unlike many other motors the polarity of the phase torque in SR motors is solely determined by the rotor position and is independent of the polarity of the applied voltage or phase current. The proposed controller takes advantage of this property and incorporates a commutation scheme which, at any time instant, selects only those motor phases for the computation of control law, which can contribute torque of the desired polarity at that instant. This feature helps in achieving the desired speed regulation/tracking objective in a power efficient manner as control efforts are applied through selective phases and counterproductive phases are left un-energized. This approach also minimizes the power loss in the motor windings thus reducing the heat generation within the motor. In order to highlight the advantages of Higher-Order Sliding-Mode controllers, a classical First-Order Sliding-Mode controller (FOSMC is also developed and applied to the same system. The comparison of the two schemes shows much reduced chattering in case of SOSMC. The performance of the proposed SOSMC controller for speed regulation is also compared with that of another sliding mode speed controller published in the literature.
Hybrid Fuzzy Sliding Mode Control of a DFIG Integrated into the Network
Belabbas Belkacem
2013-12-01
Full Text Available This paper presents the study of a variable speed wind energy conversion system using a Doubly Fed Induction Generator (DFIG based on a Fuzzy sliding mode control (FSMC applied to achieve control of active and reactive powers exchanged between the stator of the DFIG and the grid to ensure a Maximum Power Point Tracking (MPPT of a wind energy conversion system. However the principal drawback of the sliding mode, is the chattering effect which characterized by torque ripple, this phenomena is undesirable and harmful for the machines, it generates noises and additional forces of torsion on the machine shaft. In order to reduce the chattering effect, the Sign function of sliding mode controller’s discontinuous part is replaced by a fuzzy logic; we will have the fuzzy sliding mode controller (FSMC. The FSMC makes it possible to combine the performances of the two types of controllers (SMC and FLC and eliminates the chattering effect. The proposed control algorithm is applied to a DFIG where the stator is directly connected to the grid and the rotor is connected to a three-level converter structure NPC to suppress low level harmonics, higher frequencies will be filtered out by the machine. Second goal of this paper is to extract a maximum of power; the rotor side converter is controlled by using a stator flux-oriented strategy. The decoupling created by the control between active and reactive stator power allows keeping the power factor close to unity. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed. Both simulation and validation results show effectiveness of the proposed control strategy is in terms of power regulation. Moreover, the fuzzy sliding mode approach is arranged so as to reduce the chattering produced in the generated power that could lead to increased mechanical stress because of strong torque variations.
Spatiotemporal chaos synchronization of an uncertain network based on sliding mode control
The sliding mode control method is used to study spatiotemporal chaos synchronization of an uncertain network. The method is extended from synchronization between two chaotic systems to the synchronization of complex network composed of N spatiotemporal chaotic systems. The sliding surface of the network and the control input are designed. Furthermore, the effectiveness of the method is analysed based on the stability theory. The Burgers equation with spatiotemporal chaos behavior is taken as an example to simulate the experiment. It is found that the synchronization performance of the network is very stable
X33 Reusable Launch Vehicle Control on Sliding Modes: Concepts for a Control System Development
Shtessel, Yuri B.
1998-01-01
Control of the X33 reusable launch vehicle is considered. The launch control problem consists of automatic tracking of the launch trajectory which is assumed to be optimally precalculated. It requires development of a reliable, robust control algorithm that can automatically adjust to some changes in mission specifications (mass of payload, target orbit) and the operating environment (atmospheric perturbations, interconnection perturbations from the other subsystems of the vehicle, thrust deficiencies, failure scenarios). One of the effective control strategies successfully applied in nonlinear systems is the Sliding Mode Control. The main advantage of the Sliding Mode Control is that the system's state response in the sliding surface remains insensitive to certain parameter variations, nonlinearities and disturbances. Employing the time scaling concept, a new two (three)-loop structure of the control system for the X33 launch vehicle was developed. Smoothed sliding mode controllers were designed to robustly enforce the given closed-loop dynamics. Simulations of the 3-DOF model of the X33 launch vehicle with the table-look-up models for Euler angle reference profiles and disturbance torque profiles showed a very accurate, robust tracking performance.
Design of a Sliding Mode Controller for Two-Wheeled Balancing Robot
Ehsan Abbas nejad
2014-10-01
Full Text Available Nowadays, the control of mechanical systems with fewer inputs than outputs (Under-actuated systems has become a challenging problem for control engineers. Two-wheeled balancing robots is one of the appealing examples of this category. This type of robot contains two parallel wheels and an inverted pendulum. In this research, designing of controller have been investigated for flat surfaces. For controller design, the extract dynamics of the system has been achieved based on Kane's method. Then for the two-wheeled balancing robot, one sliding mode controller has been designed for yaw angle, and another sliding mode controller has been designed to control both position and pitch angle based on a proposed sliding surface. The main feature of the proposed controllers is that all of controllers have been designed based on the nonlinear dynamics of system. Also, considering the limits of uncertainties while designing systems, the robustness of controllers have been increased. The common problem of sliding mode control is chattering phenomenon that has been greatly reduced using saturation function instead of sign function. Simulation results comparision of the designed controller with a LQR controller, validates the effectiveness of the proposed controller.
Hongwen He
2014-06-01
Full Text Available This paper presents an acceleration slip regulation (ASR system for four-wheel drive (4WD electric vehicles, which are driven by the front and rear axles simultaneously. The ASR control strategy includes three control modes: average distribution of inter-axle torque, optimal distribution of inter-axle torque and independent control of optimal slip rate, respectively, which are designed based on the torque adaptive principle of inter-axle differential and sliding mode control theory. Furthermore, in order to accurately describe the longitudinal tyre force characteristic, a slip rate calculation formula in the form of a state equation was used for solving the numerical problem posed by the traditional way. A simulation was carried out with the MATLAB/Simulink software. The simulation results show that the proposed ASR system can fully use the road friction condition, inhibit the drive-wheels from slipping, and improve the vehicle longitudinal driving stability.
Fuzzy sliding mode control of a doubly fed induction generator for wind energy conversion
A. Meroufel
2013-12-01
Full Text Available In this paper we present a nonlinear control using fuzzy sliding mode for wind energy conversion system based on a doubly-fed induction generator (DFIG supplied by an AC-AC converter. In the first place, we carried out briefly a study of modeling on the whole system. In order to control the power flowing between the stator of the DFIG and the grid, a proposed control design uses fuzzy logic technique is applied for implementing a fuzzy hitting control law to remove completely the chattering phenomenon on a conventional sliding mode control. The use of this method provides very satisfactory performance for the DFIG control, and the chattering effect is also reduced by the fuzzy mode. The machine is tested in association with a wind turbine. Simulations results are presented and discussed for the whole system.
Jan Vittek
2013-01-01
Full Text Available A decomposed sliding mode control of the drive with an interior permanent magnet synchronous motor and flexible coupling is presented. Decomposition exploits principles of vector control to divide motor into channel for control of magnetic flux and channel for control of torque separately. Sliding mode control principles are exploited to keep demanded value of magnetic flux and to control load angle in the presence of vibration modes and external disturbances. To obtain continues voltage as a control variable a smoothing integrator follows signum function in both channels. As a modification the switching governed by signum function is replaced by the high gain including rearrangement of the control system block diagram. The simulations indicate that the control system yields the desired robustness and further investigations are recommended.
Bayramoglu, Husnu; Komurcugil, Hasan
2014-07-01
A time-varying sliding-coefficient-based decoupled terminal sliding mode control strategy is presented for a class of fourth-order systems. First, the fourth-order system is decoupled into two second-order subsystems. The sliding surface of each subsystem was designed by utilizing time-varying coefficients. Then, the control target of one subsystem to another subsystem was embedded. Thereafter, a terminal sliding mode control method was utilized to make both subsystems converge to their equilibrium points in finite time. The simulation results on the inverted pendulum system demonstrate that the proposed method exhibits a considerable improvement in terms of a faster dynamic response and lower IAE and ITAE values as compared with the existing decoupled control methods. PMID:24913067
严浙平; 于浩淼; 侯恕萍
2016-01-01
The problem of diving control for an underactuated unmanned undersea vehicle (UUV) considering the presence of parameters perturbations and wave disturbances was addressesed. The vertical motion of an UUV was divided into two noninteracting subsystems for surge velocity control and diving. To stabilize the vertical motion system, the surge velocity and the depth control controllers were proposed using backstepping technology and an integral-fast terminal sliding mode control (IFTSMC). It is proven that the proposed control scheme can guarantee that all the error signals in the whole closed-loop system globally converge to the sliding surface in finite time and asymptotically converge to the origin along the sliding surface. With a unified control parameters for different motion states, a series of numerical simulation results illustrate the effectiveness of the above designed control scheme, which also shows strong robustness against parameters perturbations and wave disturbances.
Shun-Yuan Wang
2015-03-01
Full Text Available This paper presents the implementation of an adaptive supervisory sliding fuzzy cerebellar model articulation controller (FCMAC in the speed sensorless vector control of an induction motor (IM drive system. The proposed adaptive supervisory sliding FCMAC comprised a supervisory controller, integral sliding surface, and an adaptive FCMAC. The integral sliding surface was employed to eliminate steady-state errors and enhance the responsiveness of the system. The adaptive FCMAC incorporated an FCMAC with a compensating controller to perform a desired control action. The proposed controller was derived using the Lyapunov approach, which guarantees learning-error convergence. The implementation of three intelligent control schemes—the adaptive supervisory sliding FCMAC, adaptive sliding FCMAC, and adaptive sliding CMAC—were experimentally investigated under various conditions in a realistic sensorless vector-controlled IM drive system. The root mean square error (RMSE was used as a performance index to evaluate the experimental results of each control scheme. The analysis results indicated that the proposed adaptive supervisory sliding FCMAC substantially improved the system performance compared with the other control schemes.
A Fault Tolerant Direct Control Allocation Scheme with Integral Sliding Modes
Hamayun Mirza Tariq
2015-03-01
Full Text Available In this paper, integral sliding mode control ideas are combined with direct control allocation in order to create a fault tolerant control scheme. Traditional integral sliding mode control can directly handle actuator faults; however, it cannot do so with actuator failures. Therefore, a mechanism needs to be adopted to distribute the control effort amongst the remaining functioning actuators in cases of faults or failures, so that an acceptable level of closed-loop performance can be retained. This paper considers the possibility of introducing fault tolerance even if fault or failure information is not provided to the control strategy. To demonstrate the efficacy of the proposed scheme, a high fidelity nonlinear model of a large civil aircraft is considered in the simulations in the presence of wind, gusts and sensor noise.
Iman Nazari
2014-03-01
Full Text Available Sliding mode controller (SMC is a significant nonlinear controller under condition of partly uncertain dynamic parameters of system. This controller is used to control of highly nonlinear systems especially for robot manipulators, because this controller is a robust and stable. Conversely, pure sliding mode controller is used in many applications; it has two important drawbacks namely; chattering phenomenon, and nonlinear equivalent dynamic formulation in uncertain dynamic parameter. The nonlinear equivalent dynamic formulation problem and chattering phenomenon in uncertain system can be solved by using artificial intelligence theorem. However fuzzy logic controller is used to control complicated nonlinear dynamic systems, but it cannot guarantee stability and robustness. In this research parallel fuzzy logic theory is used to compensate the system dynamic uncertainty.
Farzin Piltan
2013-06-01
Full Text Available Sliding mode controller (SMC is a significant nonlinear controller under condition of partly uncertain dynamic parameters of system. This controller is used to control of highly nonlinear systems especially for robot manipulators, because this controller is a robust and stable. Conversely, pure sliding mode controller is used in many applications; it has two important drawbacks namely; chattering phenomenon, and nonlinear equivalent dynamic formulation in uncertain dynamic parameter. The nonlinear equivalent dynamic formulation problem and chattering phenomenon in uncertain system can be solved by using artificial intelligence theorem. However fuzzy logic controller is used to control complicated nonlinear dynamic systems, but it cannot guarantee stability and robustness. In this research parallel fuzzy logic theory is used to compensate the system dynamic uncertainty.
Robust Fuzzy-Second Order Sliding Mode based Direct Power Control for Voltage Source Converter
D. Kairous
2015-08-01
Full Text Available This paper focuses on a second order sliding mode based direct power controller (SOSM-DPC of a three-phase grid-connected voltage source converter (VSC. The proposed control scheme combined with fuzzy logic aims at regulating the DC-link voltage of the converter and precisely tracking arbitrary power references, in order to easily control the system’s power factor. Therefore measures are proposed to reduce the chattering effects inherent to sliding-mode control (SMC. Simulations performed under Matlab/Simulink validate the feasibility of the designed Fuzzy-SOSM. Simulation results on a 1kVA grid-connected VSC under normal and faulted grid voltage conditions demonstrate good performance of the proposed control law in terms of robustness, stability and precision.
Discrete-time sliding mode control for MR vehicle suspension system
This paper presents control performance of a full-vehicle suspension system featuring magnetorheological (MR) dampers via a discrete-time sliding mode control algorithm (DSMC). A cylindrical MR damper is designed by incorporating Bingham model of the MR fluid and the field-dependent damping characteristics of the MR damper are evaluated. A full-vehicle suspension model installed with independent four MR dampers is constructed and the governing equations which include vertical, pitch and roll motion are derived. A discrete-time control model is established with considering system uncertainties and a discrete-time sliding mode controller which has inherent robustness to model uncertainty and external disturbance is formulated. Vibration control performances under bump excitation are evaluated and presented.
Research of Compound Control for DC Motor System Based on Global Sliding Mode Disturbance Observer
He Zhang
2014-01-01
Full Text Available Aiming at the problems of modeling errors, parameter variations, and load moment disturbances in DC motor control system, one global sliding mode disturbance observer (GSMDO is proposed based on the global sliding mode (GSM control theory. The output of GSMDO is used as the disturbance compensation in control system, which can improve the robust performance of DC motor control system. Based on the designed GSMDO in inner loop, one compound controller, composed of a feedback controller and a feedforward controller, is proposed in order to realize the position tracking of DC motor system. The gains of feedback controller are obtained by means of linear quadratic regulator (LQR optimal control theory. Simulation results present that the proposed control scheme possesses better tracking properties and stronger robustness against modeling errors, parameter variations, and friction moment disturbances. Moreover, its structure is simple; therefore it is easy to be implemented in engineering.
Path Following of Autonomous Vehicle in 2D Space Using Multivariable Sliding Mode Control
Daxiong Ji
2014-01-01
Full Text Available A solution to the path following problem for underactuated autonomous vehicles in the presence of possibly large modeling parametric uncertainty is proposed. For a general class of vehicles moving in 2D space, we demonstrated a path following control law based on multiple variable sliding mode that yields global boundedness and convergence of the position tracking error to a small neighborhood and robustness to parametric modeling uncertainty. An error integration element is added into the “tanh” function of the traditional sliding mode control. We illustrated our results in the context of the vehicle control applications that an underwater vehicle moves along with the desired paths in 2D space. Simulations show that the control objectives were accomplished.
Sliding modes control of active suspensions for a non-linear full vehicle model
In this study, a non-linear seven degrees of freedom vehicle model is used in order to design and check the performance of sliding modes controlled active suspensions. Force actuators are mounted as parallel to the four suspensions and a non-chattering control is realized. Sliding mode control is preferred because of its robust character since any change in vehicle parameters should not affect the performance of the active suspensions. Improvement in ride comfort is aimed by decreasing the amplitudes of motions of vehicle body. Body bounce, pitch and yaw motions of the vehicle are simulated both in time domain in case of traveling on a limited ramp type of road profile and frequency domain using linear zed vehicle model. Also phase plane plots of them are checked. Simulation results are compared with the ones of passive suspensions. (author)
Sliding Mode Predictive Control of Main Steam Pressure in Coal-fired Power Plant Boiler
史元浩; 王景成; 章云锋
2012-01-01
Since the combustion system of coal-fired boiler in thermal power plant is characterized as time varying, strongly coupled, and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional integral derivative (PID) control scheme. For the characteristics of the main steam pressure in coal-fired power plant boiler, the sliding mode control system with Smith predictive structure is proposed to look for performance and robustness improvement. First, internal model control (IMC) and Smith predictor (SP) is used to deal with the time delay, and sliding mode controller (SMCr) is designed to overcome the model mismatch. Simulation results show the effectiveness of the proposed controller compared with conventional ones.
Decoupled Sliding Mode Control for a Novel 3-DOF Parallel Manipulator with Actuation Redundancy
Niu Xuemei; Guoqin Gao; Xinjun Liu; Zhiming Fang
2015-01-01
This paper presents a decoupled nonsingular terminal sliding mode controller (DNTSMC) for a novel 3-DOF parallel manipulator with actuation redundancy. According to kinematic analysis, the inverse dynamic model for a novel 3-DOF redundantly actuated parallel manipulator is formulated in the task space using Lagrangian formalism and decoupled into three entirely independent subsystems under generalized coordinates to significantly reduce system complexity. Based on the dynamic model, a decoupl...
Qiang Qu; Fuyang Chen; Bin Jiang; Gang Tao
2015-01-01
A novel self-repairing control scheme is proposed for a helicopter with unknown disturbance. Firstly, a disturbance observer is introduced to observe the disturbance of the system, which can produce corresponding control signals according to the disturbance signals. Secondly, an integral sliding mode controller is designed to compensate the unobserved disturbance and uncertainties. All of the closed-loop poles can be arbitrarily placed and the output errors converge to zero effectively throug...
Sliding Mode Control of the Battery Bank for the Fuel Cell-based Distributed Generation System
Junsheng Jiao
2013-01-01
The dynamic models for the fuel cell power and the configuration of the fuel cell distributed generation system are shown in this paper. Due to nonlinear characteristics of fuel cell model, the output voltage of fuel cell varies greatly when the load changes. A novel interface is designed to provide a constant output voltage for charging of the battery bank of the fuel cell distributed generation. The thesis presents a sliding mode control design of PEMFC distributed generation system. A casc...
Analysis of a bidirecctional coupled-inductor Cuk converter operating in sliding mode
Martínez Salamero, Luis; Calvente Calvo, Francisco Javier; Giral, Roberto; Poveda López, Alberto; Fossas Colet, Enric
1998-01-01
Analytic models for a bidirectional coupled-inductor Cuk converter operating in sliding mode are described. Using a linear combination of the converter four state variable errors as a general switching surface, the expression for the equivalent control is derived and the coordinates of the equilibrium point are obtained. Particular cases of the general switching surface are subsequently analyzed in detail: 1) surfaces for ideal line regulation, 2) surfaces for ideal load regulation, and 3) su...
On sliding mode observer for a hybrid three-cell converter
Khelouat, Samir
2013-10-01
In this paper, we propose a sliding mode observer to estimate the capacitor voltages of the 3-cell converter. New concept recently introduced, based on geometrical condition for observability analysis is used. The convergence of estimation error based on the solution of an LMI system is shown. Finally, illustrative results are given in order to show the efficiency of the designed observer. © 2013 IEEE.
A sliding mode control proposal for open-loop unstable processes.
Rojas, Rubén; Camacho, Oscar; González, Luis
2004-04-01
This papers presents a sliding mode controller based on a first-order-plus-dead-time model of the process for controlling open-loop unstable systems. The proposed controller has a simple and fixed structure with a set of tuning equations as a function of the desired performance. Both linear and nonlinear models were used to study the controller performance by computer simulations. PMID:15098584
Application of MPC and sliding mode control to IFAC benchmark models
McGookin, M.; Anderson, D; McGookin, E.
2008-01-01
The comparison of Model Predictive Control (MPC) and Sliding Mode Control (SMC) are presented in this paper. This paper investigates the performance of each controller as the navigation system for IFAC benchmark ship models (cargo vessel and oil tanker). In this investigation the navigation system regulates the heading angle of the two types of marine vessel with reference to a desired heading trajectory. In this investigation, the result obtained from MPC is compared with a well-...
Mingchao Xia; Yanhui Mao
2013-01-01
Control strategies of D-STATCOM for unbalanced load compensation under internal and external disturbances were discussed. Linear control strategies do not have a satisfactory dynamic performance and become invalid under internal or external disturbances. To guarantee a good precision and robustness, a control strategy combining input-output feedback linearization technique with integral sliding mode control (ISMC) method was applied to D-STATCOM for unbalanced load compensation. The strategy ...
Benzineb, Omar
2013-01-01
In this article, the diagnosis of a three cell converter is developed. The hybrid nature of the system represented by the presence of continuous and discrete dynamics is taken into account in the control design. The idea is based on using a hybrid control and an observer-type sliding mode to generate residuals from the observation errors of the system. The simulation results are presented at the end to illustrate the performance of the proposed approach. © 2013 FEI STU.
Path Following of Autonomous Vehicle in 2D Space Using Multivariable Sliding Mode Control
Daxiong Ji; Jian Liu; Hongyu Zhao; Yiqun Wang
2014-01-01
A solution to the path following problem for underactuated autonomous vehicles in the presence of possibly large modeling parametric uncertainty is proposed. For a general class of vehicles moving in 2D space, we demonstrated a path following control law based on multiple variable sliding mode that yields global boundedness and convergence of the position tracking error to a small neighborhood and robustness to parametric modeling uncertainty. An error integration element is added into the “t...
Second Order Sliding Mode Control with Prescribed Convergence Law for Electro-Hydraulic Drives
Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.;
2013-01-01
This paper discusses the application of second order sliding modes for position tracking control of electro-hydraulic valve-cylinder drives (VCD’s). The target is to introduce increased tracking- and transient performance compared to conventional linear approaches, without extending the number of...... tuning parameters. The proposed controller utilizes basic component knowledge commonly available from data sheets, as well as pressure-, valve position-, piston position- and velocity measurements. Results demonstrate improved position tracking- and transient performance, compared to a linear control...
Model Reference Sliding Mode Control of Small Helicopter X.R.B based on Vision
Wei Wang; Kenzo Nonami; Yuta Ohira
2008-01-01
This paper presents autonomous control for indoor small helicopter X.R.B. In case of natural disaster like earthquake, a MAV (Micro Air Vehicle) which can fly autonomously will be very effective for surveying the site and environment in dangerous area or narrow space, where human cannot access safely. In addition, it will be helpful to prevent secondary disaster. This paper describes vision based autonomous hovering control, guidance control for X.R.B by model reference sliding mode control.
Sensorless Vector Control of AC Induction Motor Using Sliding-Mode Observer
Phuc Thinh Doan
2013-06-01
Full Text Available This paper develops a sensorless vector controlled method for AC induction motor using sliding-mode observer. For developing the control algorithm, modeling of AC induction motor is presented. After that, a sliding mode observer is proposed to estimate the motor speed, the rotor flux, the angular position of the rotor flux and the motor torque from monitored stator voltages and currents. The use of the nonlinear sliding mode observer provides very good performance for both low and high speed motor operation. Furthermore, the proposed system is robust in motor losses and load variations. The convergence of the proposed observer is obtained using the Lyapunov theory. Hardware and software for simulation and experiment of the AC induction motor drive are introduced. The hardware consists of a 1.5kw AC induction motor connected in series with a torque sensor and a powder brake. A controller is developed based on DSP TMS320F28355. The simulation and experimental results illustrate that fast torque and speed response with small torque ripples can be achieved. The proposed control scheme is suitable to the application fields that require high performance of torque response such as electric vehicles. doi:http://dx.doi.org/10.12777/ijse.4.2.2013.39-43 [How to cite this article: Doan, P. T., Nguyen, T. T., Jeong, S. K., Oh, S. J., & Kim, S. B. (2013. Sensorless Vector Control of AC Induction Motor Using Sliding-Mode Observer. INTERNATIONAL JOURNAL OF SCIENCE AND ENGINEERING, 4(2, 39-43; doi: http://dx.doi.org/10.12777/ijse.4.2.2013.39-43
Sliding Mode Control for Nonlinear System Based on T-S Model
WU Zhong-qiang
2002-01-01
Using T-S model as an approximation for nonlinear system, the nonlinear system has been fuzzy into local linear model. The variable structure controller designed by using Lyapunov theory insures the stability of system. The sliding mode controller is designed by using unit vector style, and it suit the uncertain elements satisfying matching condition or do not satisfy matching condition. The effect of the scheme has been tasted with a simulation of an inverted pendulum.
Gao, Qing; Feng, Gang; Xi, Zhiyu; Wang, Yong; Qiu, Jianbin
2014-09-01
In this paper, a novel dynamic sliding mode control scheme is proposed for a class of uncertain stochastic nonlinear time-delay systems represented by Takagi-Sugeno fuzzy models. The key advantage of the proposed scheme is that two very restrictive assumptions in most existing sliding mode control approaches for stochastic fuzzy systems have been removed. It is shown that the closed-loop control system trajectories can be driven onto the sliding surface in finite time almost certainly. It is also shown that the stochastic stability of the resulting sliding motion can be guaranteed in terms of linear matrix inequalities; moreover, the sliding-mode controller can be obtained simultaneously. Simulation results illustrating the advantages and effectiveness of the proposed approaches are also provided. PMID:25137685
RTDS implementation of an improved sliding mode based inverter controller for PV system.
Islam, Gazi; Muyeen, S M; Al-Durra, Ahmed; Hasanien, Hany M
2016-05-01
This paper proposes a novel approach for testing dynamics and control aspects of a large scale photovoltaic (PV) system in real time along with resolving design hindrances of controller parameters using Real Time Digital Simulator (RTDS). In general, the harmonic profile of a fast controller has wide distribution due to the large bandwidth of the controller. The major contribution of this paper is that the proposed control strategy gives an improved voltage harmonic profile and distribute it more around the switching frequency along with fast transient response; filter design, thus, becomes easier. The implementation of a control strategy with high bandwidth in small time steps of Real Time Digital Simulator (RTDS) is not straight forward. This paper shows a good methodology for the practitioners to implement such control scheme in RTDS. As a part of the industrial process, the controller parameters are optimized using particle swarm optimization (PSO) technique to improve the low voltage ride through (LVRT) performance under network disturbance. The response surface methodology (RSM) is well adapted to build analytical models for recovery time (Rt), maximum percentage overshoot (MPOS), settling time (Ts), and steady state error (Ess) of the voltage profile immediate after inverter under disturbance. A systematic approach of controller parameter optimization is detailed. The transient performance of the PSO based optimization method applied to the proposed sliding mode controlled PV inverter is compared with the results from genetic algorithm (GA) based optimization technique. The reported real time implementation challenges and controller optimization procedure are applicable to other control applications in the field of renewable and distributed generation systems. PMID:26606852
Ahmed M. Kassem
2012-05-01
Full Text Available A position control of DC motor servo drive based on the Sliding Mode (SM approach is presented. The modeling and analysis of the servo DC motor are obtained. The Sliding Mode Controller (SMC design changes such that its performance is substantially improved. To improve the controller performance in steady stat (zero error the Integral Sliding Mode Controller (ISMC is used. Since the main drawback of SMC is a phenomenon, the so-called chattering, resulting from discontinuous controllers. A ISMC with switched gains is used for chattering reduction and controller robustness. For comparison, the proposed ISM with switched gains is compared with that of a PID controller. Experiments and simulations have been carried out in order to validate the effectiveness of the proposed scheme. The proposed controller offers very good tracking; it is highly robust, reaches the final position very fast. Furthermore the application of the SM ensures reduction of the system order by one. Also, quick recovery from matched disturbance in addition to good tracking ability. Moreover, this scheme is robust against the parameters variations and eliminate the influence of modeling.
The grid-connected PV inverter control basing the exponential sliding mode
Huo, Qunhai; Kong, Li; Pei, Wei; Huang, Shengli; Zhou, Jing [Institute of Electrical Engineering, CAS, Beijing (China)
2008-07-01
In order to improve the dynamic performance of the grid-connected PV inverter control system, reduce the hardware and software cost of inverter control design, in view of grid-connected inverter non-linear mathematical model, this paper proposes the design of single-phase current closed loop grid-connected PV inverter control system using the Exponential Sliding Mode Control of the modern control theory. Theory testify of the Exponential Sliding Mode Approach Law applied in the grid-connected inverter is completed, and system stability was proven using Lyapunov theorem. In view of the question of chosen Sliding Mode Approach Law existence the non-linearity possibly to cause system buffeting, used the unit to control continuous method, it can enable smooth after the control having high gain characteristic nearby the cut surface, and it has the resistance disturbance and parameter perturbation ability. Compared with the conventional control system, the result had proven proposed the control strategy accurate, and the system has a good control precision and followed characteristic. (orig.)
Current Sensor Fault Diagnosis Based on a Sliding Mode Observer for PMSM Driven Systems
Gang Huang
2015-05-01
Full Text Available This paper proposes a current sensor fault detection method based on a sliding mode observer for the torque closed-loop control system of interior permanent magnet synchronous motors. First, a sliding mode observer based on the extended flux linkage is built to simplify the motor model, which effectively eliminates the phenomenon of salient poles and the dependence on the direct axis inductance parameter, and can also be used for real-time calculation of feedback torque. Then a sliding mode current observer is constructed in αβ coordinates to generate the fault residuals of the phase current sensors. The method can accurately identify abrupt gain faults and slow-variation offset faults in real time in faulty sensors, and the generated residuals of the designed fault detection system are not affected by the unknown input, the structure of the observer, and the theoretical derivation and the stability proof process are concise and simple. The RT-LAB real-time simulation is used to build a simulation model of the hardware in the loop. The simulation and experimental results demonstrate the feasibility and effectiveness of the proposed method.
Kawano, Yoshihiro; Higgins, Christopher; Yamamoto, Yasuhito; Nyhus, Julie; Bernard, Amy; Dong, Hong-Wei; Karten, Harvey J; Schilling, Tobias
2013-01-01
We present a new method for whole slide darkfield imaging. Whole Slide Imaging (WSI), also sometimes called virtual slide or virtual microscopy technology, produces images that simultaneously provide high resolution and a wide field of observation that can encompass the entire section, extending far beyond any single field of view. For example, a brain slice can be imaged so that both overall morphology and individual neuronal detail can be seen. We extended the capabilities of traditional whole slide systems and developed a prototype system for darkfield internal reflection illumination (DIRI). Our darkfield system uses an ultra-thin light-emitting diode (LED) light source to illuminate slide specimens from the edge of the slide. We used a new type of side illumination, a variation on the internal reflection method, to illuminate the specimen and create a darkfield image. This system has four main advantages over traditional darkfield: (1) no oil condenser is required for high resolution imaging (2) there is less scatter from dust and dirt on the slide specimen (3) there is less halo, providing a more natural darkfield contrast image, and (4) the motorized system produces darkfield, brightfield and fluorescence images. The WSI method sometimes allows us to image using fewer stains. For instance, diaminobenzidine (DAB) and fluorescent staining are helpful tools for observing protein localization and volume in tissues. However, these methods usually require counter-staining in order to visualize tissue structure, limiting the accuracy of localization of labeled cells within the complex multiple regions of typical neurohistological preparations. Darkfield imaging works on the basis of light scattering from refractive index mismatches in the sample. It is a label-free method of producing contrast in a sample. We propose that adapting darkfield imaging to WSI is very useful, particularly when researchers require additional structural information without the use of
Yoshihiro Kawano
Full Text Available We present a new method for whole slide darkfield imaging. Whole Slide Imaging (WSI, also sometimes called virtual slide or virtual microscopy technology, produces images that simultaneously provide high resolution and a wide field of observation that can encompass the entire section, extending far beyond any single field of view. For example, a brain slice can be imaged so that both overall morphology and individual neuronal detail can be seen. We extended the capabilities of traditional whole slide systems and developed a prototype system for darkfield internal reflection illumination (DIRI. Our darkfield system uses an ultra-thin light-emitting diode (LED light source to illuminate slide specimens from the edge of the slide. We used a new type of side illumination, a variation on the internal reflection method, to illuminate the specimen and create a darkfield image. This system has four main advantages over traditional darkfield: (1 no oil condenser is required for high resolution imaging (2 there is less scatter from dust and dirt on the slide specimen (3 there is less halo, providing a more natural darkfield contrast image, and (4 the motorized system produces darkfield, brightfield and fluorescence images. The WSI method sometimes allows us to image using fewer stains. For instance, diaminobenzidine (DAB and fluorescent staining are helpful tools for observing protein localization and volume in tissues. However, these methods usually require counter-staining in order to visualize tissue structure, limiting the accuracy of localization of labeled cells within the complex multiple regions of typical neurohistological preparations. Darkfield imaging works on the basis of light scattering from refractive index mismatches in the sample. It is a label-free method of producing contrast in a sample. We propose that adapting darkfield imaging to WSI is very useful, particularly when researchers require additional structural information without the
Anti-Synchronization of the Hyperchaotic Lorenz Systems by Sliding Mode Control
Dr. V. Sundarapandian,
2011-06-01
Full Text Available This paper investigates the problem of global chaos anti-synchronization of identical hyperchaotic Lorenz systems (Jia, 2007 by sliding mode control. The stability results derived in this paper for the anti-synchronization of identical hyperchaotic Lorenz systems are established using Lyapunov stability theory. Since the Lyapunov exponents are not required for these calculations, thesliding mode control method is very effective and convenient to achieve global chaos synchronization of the identical hyperchaotic Lorenz systems. Numerical simulations are shown to illustrate the effectiveness of the synchronization schemes derived in this paper.
Biel Solé, Domingo; Fossas Colet, Enric
2012-01-01
The increased efficiency and quality constraints imposed on electrical energy systems have inspired a renewed research interest in the study of formal approaches to the analysis and control of power electronics converters. Switched systems represent a useful framework for modeling these converters and the peculiarities of their operating conditions and control goals justify the specific classification of “switched electronic systems”. Indeed, idealized switched models of power converters intr...
Sliding Mode Control of a Multi-Degree-of-Freedom Structural System With Active Tuned Mass Damper
YAĞIZ, Nurkan
2001-01-01
In this study, a sliding mode control system is designed for a multi-degree-of-freedom structure having an Active Tuned Mass Damper (ATMD) to suppress earthquake or wind induced vibration. Since the model might have uncertainties and/or parameter changes, sliding mode control is preferred because of its robust character and superior performance. In addition this control method can easily be applied to non-linear systems. The simulated system has five degrees of freedom. In this stu...
Mekki, Hemza; Benzineb, Omar; Boukhetala, Djamel; Tadjine, Mohamed; Benbouzid, Mohamed
2015-07-01
The fault-tolerant control problem belongs to the domain of complex control systems in which inter-control-disciplinary information and expertise are required. This paper proposes an improved faults detection, reconstruction and fault-tolerant control (FTC) scheme for motor systems (MS) with typical faults. For this purpose, a sliding mode controller (SMC) with an integral sliding surface is adopted. This controller can make the output of system to track the desired position reference signal in finite-time and obtain a better dynamic response and anti-disturbance performance. But this controller cannot deal directly with total system failures. However an appropriate combination of the adopted SMC and sliding mode observer (SMO), later it is designed to on-line detect and reconstruct the faults and also to give a sensorless control strategy which can achieve tolerance to a wide class of total additive failures. The closed-loop stability is proved, using the Lyapunov stability theory. Simulation results in healthy and faulty conditions confirm the reliability of the suggested framework. PMID:25747198
Nonsingular decoupled terminal sliding-mode control for a class of fourth-order nonlinear systems
Bayramoglu, Husnu; Komurcugil, Hasan
2013-09-01
This paper presents a nonsingular decoupled terminal sliding mode control (NDTSMC) method for a class of fourth-order nonlinear systems. First, the nonlinear fourth-order system is decoupled into two second-order subsystems which are referred to as the primary and secondary subsystems. The sliding surface of each subsystem was designed by utilizing time-varying coefficients which are computed by linear functions derived from the input-output mapping of the one-dimensional fuzzy rule base. Then, the control target of the secondary subsystem was embedded to the primary subsystem by the help of an intermediate signal. Thereafter, a nonsingular terminal sliding mode control (NTSMC) method was utilized to make both subsystems converge to their equilibrium points in finite time. The simulation results on the inverted pendulum system are given to show the effectiveness of the proposed method. It is seen that the proposed method exhibits a considerable improvement in terms of a faster dynamic response and lower IAE and ITAE values as compared with the existing decoupled control methods.
Sliding Mode Output Feedback Control of a Flexible Rotor Supported by Magnetic Bearings
A. S. Lewis
2001-01-01
Full Text Available A new sliding mode feedback algorithm is applied to control the vibration of a flexible rotor supported by magnetic bearings. It is assumed that the number of states is greater than the number of sensors. A mathematical model of the rotor]magnetic bearing system is presented in terms of partial differential equations. These equations are then discretized into a finite number of ordinary differential equations through Galerkin’s method. The sliding mode control law is designed to be robust to rotor unbalance and transient disturbances. A boundary layer is introduced around each sliding hyperplane to eliminate the chattering phenomenon. The results from numerical simulations are presented that not only corroborate the validity of the proposed controller, but also show the effects of various control parameters as a function of the angular speed of the rotor. In addition, results are presented that indicate how the current required by the magnetic bearings is affected by control parameters and the angular speed of the rotor.
Variable speed wind turbine control by discrete-time sliding mode approach.
Torchani, Borhen; Sellami, Anis; Garcia, Germain
2016-05-01
The aim of this paper is to propose a new design variable speed wind turbine control by discrete-time sliding mode approach. This methodology is designed for linear saturated system. The saturation constraint is reported on inputs vector. To this end, the back stepping design procedure is followed to construct a suitable sliding manifold that guarantees the attainment of a stabilization control objective. It is well known that the mechanisms are investigated in term of the most proposed assumptions to deal with the damping, shaft stiffness and inertia effect of the gear. The objectives are to synthesize robust controllers that maximize the energy extracted from wind, while reducing mechanical loads and rotor speed tracking combined with an electromagnetic torque. Simulation results of the proposed scheme are presented. PMID:26804750
This paper describes the robust optimal incremental motion control of a current sensor less synchronous reluctance motor, which can be specified by any desired speed profile. The control scheme is a combination of conventional linear quadratic feed back control method and sliding mode control. A novel sliding switching surface is employed first, that makes the states of the synchronous reluctance motor follow the nominal trajectories (controlled by any type of nominal controller) when the motor parameter uncertainties and the disturbance load torque exist. The sliding mode controller has no reaching phase and produces small sliding mode control chattering. Then, using the above tracking controller, the well-known torque control schemes, maximum torque, constant current inductive axis control and maximum power factor control related to the synchronous reluctance motor are examined below and above the base speed. Finally the validity of our proposed control scheme is verified by computer simulation results
Adaptive Control of Flexible Structures Using Residual Mode Filters
Balas, Mark J.; Frost, Susan
2010-01-01
Flexible structures containing a large number of modes can benefit from adaptive control techniques which are well suited to applications that have unknown modeling parameters and poorly known operating conditions. In this paper, we focus on a direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend our adaptive control theory to accommodate troublesome modal subsystems of a plant that might inhibit the adaptive controller. In some cases the plant does not satisfy the requirements of Almost Strict Positive Realness. Instead, there maybe be a modal subsystem that inhibits this property. This section will present new results for our adaptive control theory. We will modify the adaptive controller with a Residual Mode Filter (RMF) to compensate for the troublesome modal subsystem, or the Q modes. Here we present the theory for adaptive controllers modified by RMFs, with attention to the issue of disturbances propagating through the Q modes. We apply the theoretical results to a flexible structure example to illustrate the behavior with and without the residual mode filter. We have proposed a modified adaptive controller with a residual mode filter. The RMF is used to accommodate troublesome modes in the system that might otherwise inhibit the adaptive controller, in particular the ASPR condition. This new theory accounts for leakage of the disturbance term into the Q modes. A simple three-mode example shows that the RMF can restore stability to an otherwise unstable adaptively controlled system. This is done without modifying the adaptive controller design.
Drag-based composite super-twisting sliding mode control law design for Mars entry guidance
Zhao, Zhenhua; Yang, Jun; Li, Shihua; Guo, Lei
2016-06-01
In this paper, the drag-based trajectory tracking guidance problem is investigated for Mars entry vehicle subject to uncertainties. A composite super twisting sliding mode control method based on finite-time disturbance observer is proposed for guidance law design. The proposed controller not only eliminates the effects of matched and mismatched disturbances due to uncertainties of atmospheric models and vehicle aerodynamics but also guarantees the continuity of control action. Numerical simulations are carried out on the basis of Mars Science Laboratory mission, where the results show that the proposed methods can improve the Mars entry guidance precision as compared with some existing guidance methods including PID and ADRC.
A Sliding Mode Control for a Sensorless Tracker: Application on a Photovoltaic System
Rhif, Ahmed
2012-01-01
The photovoltaic sun tracker allows us to increase the energy production. The sun tracker considered in this study has two degrees of freedom (2-DOF) and especially specified by the lack of sensors. In this way, the tracker will have as a set point the sun position at every second during the day for a period of five years. After sunset, the tracker goes back to the initial position (which of sunrise). The sliding mode control (SMC) will be applied to ensure at best the tracking mechanism and,...
Sliding Mode Control for NSVs with Input Constraint Using Neural Network and Disturbance Observer
Yan-long Zhou
2013-01-01
Full Text Available The sliding mode control (SMC scheme is proposed for near space vehicles (NSVs with strong nonlinearity, high coupling, parameter uncertainty, and unknown time-varying disturbance based on radial basis function neural networks (RBFNNs and the nonlinear disturbance observer (NDO. Considering saturation characteristic of rudders, RBFNNs are constructed as a compensator to overcome the saturation nonlinearity. The stability of the closed-loop system is proved, and the tracking error as well as the disturbance observer error can converge to the origin through the Lyapunov analysis. Simulation results are presented to demonstrate the effectiveness of the proposed flight control scheme.
Second-order sliding mode control of a 2D torsional MEMS micromirror with sidewall electrodes
A second-order sliding mode control (2-SMC) scheme with a proportional integral derivative (PID) sliding surface, to achieve enhanced transient response, accurate positioning and precise tracking performance of a 2-degree-of-freedom (2D) torsional MEMS micromirror with sidewall electrodes, is developed in this paper. The PID sliding surface is chosen to achieve a zero steady-state error of the closed-loop system. The 2-SMC is able to reduce the chattering phenomena, which comprises of an equivalent control and switching control to dominate model uncertainty and external disturbances leading to an enhanced performance of the controlled system. Finite-time convergence of the closed-loop system in the presence of bounded parameter uncertainties and external disturbances is guaranteed through Lyapunov stability analysis. The proposed 2-SMC is programmed in a LABVIEW environment and implemented based on National Instrument (NI) field-programmable gate array hardware to verify the effectiveness and robustness. The experimental results of set-point regulation and sinusoidal trajectory tacking demonstrate that the closed-loop system with the proposed control scheme significantly improves the transient performance, accurate positioning and trajectory tracking with robustness against external disturbance. The 95% settling time is shortened from 70 to 3 ms for the X-axis and from 60 to 3 ms for the Y-axis respectively, the overshoots and steady-state errors are eliminated in both axes, and less than 5% maximum positioning error is achieved in the presence of external disturbance. (paper)
Long, Yi; Du, Zhi-jiang; Wang, Wei-dong; Dong, Wei
2016-01-01
A lower limb assistive exoskeleton is designed to help operators walk or carry payloads. The exoskeleton is required to shadow human motion intent accurately and compliantly to prevent incoordination. If the user's intention is estimated accurately, a precise position control strategy will improve collaboration between the user and the exoskeleton. In this paper, a hybrid position control scheme, combining sliding mode control (SMC) with a cerebellar model articulation controller (CMAC) neural network, is proposed to control the exoskeleton to react appropriately to human motion intent. A genetic algorithm (GA) is utilized to determine the optimal sliding surface and the sliding control law to improve performance of SMC. The proposed control strategy (SMC_GA_CMAC) is compared with three other types of approaches, that is, conventional SMC without optimization, optimal SMC with GA (SMC_GA), and SMC with CMAC compensation (SMC_CMAC), all of which are employed to track the desired joint angular position which is deduced from Clinical Gait Analysis (CGA) data. Position tracking performance is investigated with cosimulation using ADAMS and MATLAB/SIMULINK in two cases, of which the first case is without disturbances while the second case is with a bounded disturbance. The cosimulation results show the effectiveness of the proposed control strategy which can be employed in similar exoskeleton systems. PMID:27069353
Sliding mode control of reaction flywheel-based brushless DC motor with buck converter
Liu Gang; Zhang Cong
2013-01-01
Reaction flywheel is a significant actuator for satellites' attitude control.To improve out-put torque and rotational speed accuracy for reaction flywheel,this paper reviews the modeling and control approaches of DC-DC converters and presents an application of the variable structure system theory with associated sliding regimes.Firstly,the topology of reaction flywheel is constructed.The small signal linearization process for a buck converter is illustrated.Then,based on the state averaging models and reaching qualification expressed by the Lee derivative,the general results of the sliding mode control (SMC) are analyzed.The analytical equivalent control laws for reaction flywheel are deduced detailedly by selecting various sliding surfaces at electromotion,energy consumption braking,reverse connection braking stages.Finally,numerical and experimental examples are presented for illustrative purposes.The results demonstrate that favorable agreement is established between the simulations and experiments.The proposed control strategy achieves preferable rotational speed regulation,strong rejection of modest disturbances,and high-precision output torque and rotational speed tracking abilities.
Long, Yi; Du, Zhi-Jiang; Wang, Wei-Dong; Dong, Wei
2016-01-01
A lower limb assistive exoskeleton is designed to help operators walk or carry payloads. The exoskeleton is required to shadow human motion intent accurately and compliantly to prevent incoordination. If the user's intention is estimated accurately, a precise position control strategy will improve collaboration between the user and the exoskeleton. In this paper, a hybrid position control scheme, combining sliding mode control (SMC) with a cerebellar model articulation controller (CMAC) neural network, is proposed to control the exoskeleton to react appropriately to human motion intent. A genetic algorithm (GA) is utilized to determine the optimal sliding surface and the sliding control law to improve performance of SMC. The proposed control strategy (SMC_GA_CMAC) is compared with three other types of approaches, that is, conventional SMC without optimization, optimal SMC with GA (SMC_GA), and SMC with CMAC compensation (SMC_CMAC), all of which are employed to track the desired joint angular position which is deduced from Clinical Gait Analysis (CGA) data. Position tracking performance is investigated with cosimulation using ADAMS and MATLAB/SIMULINK in two cases, of which the first case is without disturbances while the second case is with a bounded disturbance. The cosimulation results show the effectiveness of the proposed control strategy which can be employed in similar exoskeleton systems. PMID:27069353
Energy optimized sliding-mode control of sensorless induction motor drives
In this paper a sensorless sliding-mode (SM) direct torque and flux control is described for three-phase induction motor (IM) drive. The IM drive is supplied with a two level space vector modulation (SVM) voltage source inverter. A conventional PI speed controller is employed to generate the desired torque command in the case of speed control. Stator and rotor flux vectors are estimated using a sliding-mode observer and are employed in rotor speed estimation. Moreover, the IM model includes the iron losses through a speed dependent shunt resistance in the motor two axis equivalent circuits. Motor efficiency is also optimized by adjusting the magnitude of the stator flux reference for each value of motor load and speed. For this purpose, an on-line search method (OSM) is adopted. According to this method, for each given value of load torque and rotor speed, the stator flux reference is adjusted so that the average of real input power becomes minimized. Simulation and experimental results are presented to show the capability and validity of the proposed control scheme.
Estimation of the shear force in transverse dynamic force microscopy using a sliding mode observer
Thang Nguyen
2015-09-01
Full Text Available In this paper, the problem of estimating the shear force affecting the tip of the cantilever in a Transverse Dynamic Force Microscope (TDFM using a real-time implementable sliding mode observer is addressed. The behaviour of a vertically oriented oscillated cantilever, in close proximity to a specimen surface, facilitates the imaging of the specimen at nano-metre scale. Distance changes between the cantilever tip and the specimen can be inferred from the oscillation amplitudes, but also from the shear force acting at the tip. Thus, the problem of accurately estimating the shear force is of significance when specimen images and mechanical properties need to be obtained at submolecular precision. A low order dynamic model of the cantilever is derived using the method of lines, for the purpose of estimating the shear force. Based on this model, an estimator using sliding mode techniques is presented to reconstruct the unknown shear force, from only tip position measurements and knowledge of the excitation signal applied to the top of the cantilever. Comparisons to methods assuming a quasi-static harmonic balance are made.
Zool H. Ismail
2015-01-01
Full Text Available The main goal in developing closed loop control system for an Autonomous Underwater Vehicle (AUV is to make a robust vehicle from natural and exogenous perturbations such as wind, wave, and ocean currents. However a well-known robust control, for instance, Sliding Mode Controller (SMC, gives a chattering effect and it influences the stability of an AUV. Furthermore, some researchers combined other controls to get better result but it tends to present long computational time and causes large energy consumption. Thus, this paper proposed a Super Twisting Sliding Mode Controller (STSMC with dynamic region concept for an AUV. STSMC or a second order SMC is adopted as a robust controller which is free from chattering effect. Meanwhile, the implementation of dynamic region is useful to reduce the energy usage. As a result, the proposed controller obtains global asymptotic stability which is validated by using Lyapunov-like function. Moreover, some simulations present the efficiency of proposed controller. In conclusion, STSMC with region based control is effective to be applied for the robust tracking of an AUV. It contributes to give a fast response when handling the perturbations, short computational time, and low energy demand.
Maneuver and vibration reduction of flexible spacecraft using sliding mode/command shaping technique
HU Qing-lei; MA Guang-fu; ZHANG Wei
2006-01-01
A generalized scheme based on the sliding mode and component synthesis vibration suppression (CSVS) method has been proposed for the rotational maneuver and vibration suppression of an orbiting spacecraft with flexible appendages. The proposed control design process is twofold: design of the attitude controller followed by the design of a flexible vibration attenuator. The attitude controller using only the attitude and the rate information for the flexible spacecraft (FS) is designed to serve two purposes: it forces the attitude motion onto a pre-selected sliding surface and then guides it to the state space origin. The shaped command input controller based on the CSVS method is designed for the reduction of the flexible mode vibration, which only requires information about the natural frequency and damping of the closed system. This information is used to discretize the input so that minimum energy is injected via the controller to the flexible nodes of the spacecraft. Additionally, to extend the CSVS method to the system with the on-off actuators, the pulse-width pulse-frequency ( PWPF) modulation is introduced to control the thruster firing and integrated with the CSVS method. PWPF modulation is a control method that provides pseudo-linear operation for an on-off thruster. The proposed control strategy has been implemented on a FS, which is a hub with symmetric cantilever flexible beam appendages and can undergo a single axis rotation. The results have been proven the potential of this technique to control FS.
Elhadj BOUNADJA
2016-07-01
Full Text Available The present work examines a direct torque control strategy using a high order sliding mode controllers of a doubly-fed induction generator (DFIG incorporated in a wind energy conversion system and working in saturated state. This research is carried out to reach two main objectives. Firstly, in order to introduce some accuracy for the calculation of DFIG performances, an accurate model considering magnetic saturation effect is developed. The second objective is to achieve a robust control of DFIG based wind turbine. For this purpose, a Direct Torque Control (DTC combined with a High Order Sliding Mode Control (HOSMC is applied to the DFIG rotor side converter. Conventionally, the direct torque control having hysteresis comparators possesses major flux and torque ripples at steady-state and moreover the switching frequency varies on a large range. The new DTC method gives a perfect decoupling between the flux and the torque. It also reduces ripples in these grandeurs. Finally, simulated results show, accurate dynamic performances, faster transient responses and more robust control are achieved.
Smooth Sliding Mode Control for Trajectory Tracking of Greenhouse Spraying Mobile Robot
Fang Zhiming
2013-02-01
Full Text Available For the spraying mobile robot working in greenhouse, due to the inconsistency of drive motors and the rough walking surface, it is easy to track off. For the liquidity of pesticide, the load always changes even the speed jumps. Because of these uncertainties, external disturbances and the difficulty of constructing the system dynamic model, it is hard to implement the trajectory tracking control of the spraying mobile robot steadily, precisely and quickly. In order to solve the problem, a smooth sliding mode trajectory tracking control method is proposed based on the distribute control strategy for each branch. Moreover, its stability is proved using the Lyapunov function. The simulation results show that the proposed method can track the reference trajectories precisely, quickly and steadily under the strong white noise. The chattering phenomenon of the control law is restrained compared to the conventional sliding mode control. The trajectory tracking performance is better than that of the fuzzy control. The designed method is easy to realize and doesn’t need to construct the precise mathematical model, so, it affords an economical and convenient control method for solving the trajectory tracking problem of the greenhouse spraying mobile robot under various uncertain interferences.
Shanhai Jin
2012-01-01
Full Text Available This paper presents the results of quantitative performance evaluation of an authors’ new parabolic sliding mode filter, which is for removing noise from signals in robotics and mechatronics applications, based on the frequency and time domain characteristics. Based on the evaluation results, the paper presents selection guidelines of two parameters of the filter. The evaluation results show that, in the frequency domain, the noise removing capability of the filter is almost the same as that of the second-order Butterworth low-pass filter (2-LPF, but its phase lag is smaller (maximum 150 degree than that of 2-LPF (maximum 180 degree. Moreover, the filter produces smaller phase lag than a conventional parabolic sliding mode filter with appropriate selection of the parameters. In the time domain, the filter produces smaller overshoot than 2-LPF and the conventional one, while maintaining short transient time, by using an appropriately selected parameter. The presented parameter selection guidelines state that the values of the parameters should be chosen according to some estimated characteristics of the input and some desired characteristics of the output. The effectiveness of the filter and the presented guidelines is validated through numerical examples and their application to a closed-loop, force control of a robot manipulator.
Robust fuzzy neural network sliding mode control scheme for IPMSM drives
Leu, V. Q.; Mwasilu, F.; Choi, H. H.; Lee, J.; Jung, J. W.
2014-07-01
This article proposes a robust fuzzy neural network sliding mode control (FNNSMC) law for interior permanent magnet synchronous motor (IPMSM) drives. The proposed control strategy not only guarantees accurate and fast command speed tracking but also it ensures the robustness to system uncertainties and sudden speed and load changes. The proposed speed controller encompasses three control terms: a decoupling control term which compensates for nonlinear coupling factors using nominal parameters, a fuzzy neural network (FNN) control term which approximates the ideal control components and a sliding mode control (SMC) term which is proposed to compensate for the errors of that approximation. Next, an online FNN training methodology, which is developed using the Lyapunov stability theorem and the gradient descent method, is proposed to enhance the learning capability of the FNN. Moreover, the maximum torque per ampere (MTPA) control is incorporated to maximise the torque generation in the constant torque region and increase the efficiency of the IPMSM drives. To verify the effectiveness of the proposed robust FNNSMC, simulations and experiments are performed by using MATLAB/Simulink platform and a TI TMS320F28335 DSP on a prototype IPMSM drive setup, respectively. Finally, the simulated and experimental results indicate that the proposed design scheme can achieve much better control performances (e.g. more rapid transient response and smaller steady-state error) when compared to the conventional SMC method, especially in the case that there exist system uncertainties.
Muñoz Aguilar, Raúl Santiago; Rodríguez Cortés, Pedro; Dòria Cerezo, Arnau; Candela García, José Ignacio; Luna Alloza, Álvaro
2011-01-01
This paper presents a Sliding Mode Control for a wound rotor synchronous machine acting as an isolated generator connected to an unbalanced load. In order to simplify the control methodology, the standard dq-model of the machine is connected to a balanced resistive load. A switching function is defined in order to fulfill the control objective. From the desired surface, the standard sliding methodology is applied to obtain a robust and very simple controller. Then, the ac...
Farzin Piltan
2011-12-01
Full Text Available Refer to the research, design a novel SISO adaptive fuzzy sliding algorithm inverse dynamic like method (NAIDLC and application to robot manipulator has proposed in order to design high performance nonlinear controller in the presence of uncertainties. Regarding to the positive points in inverse dynamic controller, fuzzy logic controller and self tuning fuzzy sliding method, the output has improved. The main objective in this research is analyses and design of the adaptive robust controller based on artificial intelligence and nonlinear control. Robot manipulator is nonlinear, time variant and a number of parameters are uncertain, so design the best controller for this plant is the main target. Although inverse dynamic controller have acceptable performance with known dynamic parameters but regarding to uncertainty, this controller\\'s output has fairly fluctuations. In order to solve this problem this research is focoused on two methodology the first one is design a fuzzy inference system as a estimate nonlinear part of main controller but this method caused to high computation load in fuzzy rule base and the second method is focused on design novel adaptive method to reduce the computation in fuzzy algorithm.
Farzin Piltan
2012-06-01
Full Text Available Design a nonlinear controller for second order nonlinear uncertain dynamical systems is one of the most important challenging works. This paper focuses on the design, implementation and analysis of a chattering free sliding mode controller for highly nonlinear dynamic PUMA robot manipulator and compare to computed torque controller, in presence of uncertainties. In order to provide high performance nonlinear methodology, sliding mode controller and computed torque controller are selected. Pure sliding mode controller and computed torque controller can be used to control of partly known nonlinear dynamic parameters of robot manipulator. Conversely, pure sliding mode controller is used in many applications; it has an important drawback namely; chattering phenomenon which it can causes some problems such as saturation and heat the mechanical parts of robot manipulators or drivers. In order to reduce the chattering this research is used the linear saturation function boundary layer method instead of switching function method in pure sliding mode controller. These simulation models are developed as a part of a software laboratory to support and enhance graduate/undergraduate robotics courses, nonlinear control courses and MATLAB/SIMULINK courses at research and development company (SSP Co. research center, Shiraz, Iran.
Reducing False Negative Reads in RFID Data Streams Using an Adaptive Sliding-Window Approach
Herman Vermaak
2012-03-01
Full Text Available Unreliability of the data streams generated by RFID readers is among the primary factors which limit the widespread adoption of the RFID technology. RFID data cleaning is, therefore, an essential task in the RFID middleware systems in order to reduce reading errors, and to allow these data streams to be used to make a correct interpretation and analysis of the physical world they are representing. In this paper we propose an adaptive sliding-window based approach called WSTD which is capable of efficiently coping with both environmental variation and tag dynamics. Our experimental results demonstrate the efficacy of the proposed approach.
Sumantri, Bambang; Uchiyama, Naoki; Sano, Shigenori
2016-01-01
In this paper, a new control structure for a quad-rotor helicopter that employs the least squares method is introduced. This proposed algorithm solves the overdetermined problem of the control input for the translational motion of a quad-rotor helicopter. The algorithm allows all six degrees of freedom to be considered to calculate the control input. The sliding mode controller is applied to achieve robust tracking and stabilization. A saturation function is designed around a boundary layer to reduce the chattering phenomenon that is a common problem in sliding mode control. In order to improve the tracking performance, an integral sliding surface is designed. An energy saving effect because of chattering reduction is also evaluated. First, the dynamics of the quad-rotor helicopter is derived by the Newton-Euler formulation for a rigid body. Second, a constant plus proportional reaching law is introduced to increase the reaching rate of the sliding mode controller. Global stability of the proposed control strategy is guaranteed based on the Lyapunov's stability theory. Finally, the robustness and effectiveness of the proposed control system are demonstrated experimentally under wind gusts, and are compared with a regular sliding mode controller, a proportional-differential controller, and a proportional-integral-differential controller.
Fuzzy sliding-mode formation control for multirobot systems: design and implementation.
Chang, Yeong-Hwa; Chang, Chia-Wen; Chen, Chun-Lin; Tao, Chin-Wang
2012-04-01
This paper mainly addresses the decentralized formation problems for multiple robots, where a fuzzy sliding-mode formation controller (FSMFC) is proposed. The directed networks of dynamic agents with external disturbances and system uncertainties are discussed in consensus problems. To perform a formation control and to guarantee system robustness, a novel formation algorithm combining the concepts of graph theory and fuzzy sliding-model control is presented. According to the communication topology, formation stability conditions can be determined so that an FSMFC can be derived. By Lyapunov stability theorem, not only the system stability can be guaranteed, but the desired formation pattern of a multirobot system can be also achieved. Simulation results are provided to demonstrate the effectiveness of the provided control scheme. Finally, an experimental setup for the e-puck multirobot system is built. Compared to first-order formation algorithm and fuzzy neural network formation algorithm, it shows that real-time experimental results empirically support the promising performance of desire. PMID:22010151
Xingling, Shao; Honglun, Wang
2014-11-01
This paper proposes a novel hybrid control framework by combing observer-based sliding mode control (SMC) with trajectory linearization control (TLC) for hypersonic reentry vehicle (HRV) attitude tracking problem. First, fewer control consumption is achieved using nonlinear tracking differentiator (TD) in the attitude loop. Second, a novel SMC that employs extended disturbance observer (EDO) to counteract the effect of uncertainties using a new sliding surface which includes the estimation error is integrated to address the tracking error stabilization issues in the attitude and angular rate loop, respectively. In addition, new results associated with EDO are examined in terms of dynamic response and noise-tolerant performance, as well as estimation accuracy. The key feature of the proposed compound control approach is that chattering free tracking performance with high accuracy can be ensured for HRV in the presence of multiple uncertainties under control constraints. Based on finite time convergence stability theory, the stability of the resulting closed-loop system is well established. Also, comparisons and extensive simulation results are presented to demonstrate the effectiveness of the control strategy. PMID:25451817
Yi-You Hou
2014-01-01
Full Text Available This paper considers the problem of the robust stability for the nonlinear system with time-varying delay and parameters uncertainties. Based on the H∞ theorem, Lyapunov-Krasovskii theory, and linear matrix inequality (LMI optimization technique, the H∞ quasi-sliding mode controller and switching function are developed such that the nonlinear system is asymptotically stable in the quasi-sliding mode and satisfies the disturbance attenuation (H∞-norm performance. The effectiveness and accuracy of the proposed methods are shown in numerical simulations.
伺服系统的滑模变结构控制器设计%Design of Sliding Mode Controller for Servo System
李伟; 韩崇伟; 位红军; 赵宇和
2011-01-01
The uncertainty and discrete exponential reaching law in servo system cause the system buffeting, traditional PID control can not reach the requirements of system accuracy and stability. The paper studied the sliding mode variable structure control problem of. Uncertain discrete - time system. The parameter identification method was adopted to obtain the models of the controlled objects under the conditions of no - load and full load respectively, Based on th no - load testingg data and according to the second - order mode structure, the approximate model of the object was identified as the nominal model of discrete sliding moe controller design. Adaptive sliding mode reaching law was used to design the discrete sliding mode variable structure controller, with which, two control simulations were carried out respectively with two controlled object modes. The results show that the design of discrete sliding mode variable structure controller realizes stable servo system and accurate transfer guns, and is robust under the parameter perturbation and external disturbance, with smooth controller outputs.%伺服系统不确定性和离散指数趋近律造成系统的系统抖振,传统的PID控制方法难以实现系统对精度和稳定性的要求.为了提高控制系统的性能,提出滑模变结构控制问题.采用参数辨识法,分别获取被控对象在空载和满载模型,并将空载测试数据按二阶模型结构辨识得到被控对象近似模型,作为离散滑模控制器设计的标称模型,并采用自适应趋近律设计了离散滑模控制器,分别对被控对象的两个模型进行控制仿真.结果表明,离散滑模变结构控制器能够使伺服系统满足要求,对参数摄动和外部干扰具有较强的鲁棒性,提高了控制器性能,为设计提供了依据.
Direct Torque Control of Sensorless Induction Motor Drives: A Sliding-Mode Approach
Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede
2004-01-01
Direct torque control (DTC) is known to produce fast response and robust control in ac adjustable-speed drives. However, in the steady-state operation, notable torque, flux, and current pulsations occur. A new, direct torque and flux control strategy based on variable-structure control and space......-vector pulsewidth modulation is proposed for induction motor sensorless drives. The DTC transient merits and robustness are preserved and the steady-state behaviour is improved by reducing the torque and flux pulsations. A sliding-mode observer using a dual reference frame motor model is introduced and tested....... Simulations and comparative experimental results with the proposed control scheme, versus classic DTC, are presented. Very-low-speed sensorless operation (3 r/min) is demonstrated....
Sliding Mode Control of H Bridge Inverter Based DSTATCOM for Reactive
S. Krishna Kumar
2014-12-01
Full Text Available Reactive power compensation plays a key role in reducing distribution losses by improving power factor. A three phase three wire DSTATCOM consisting of a five level H-bridge Voltage Source Converter (VSC is proposed for improving power factor in the distribution system at the Point of Common Coupling (PCC when the load is continuously changing. The sliding mode control algorithm is used for reactive power compensation and achieve unity power factor. To accomplish this DSTATCOM is controlled to supply or absorb reactive power at PCC. Sinusoidal PWM method is used for obtaining the switching pulses for the cascaded H-bridge converter. The performance of the DSTATCOM controlled distribution system is validated by simulations using MATLAB/Simulink software and Power System block set toolboxes.
Sliding Mode Control of the Battery Bank for the Fuel Cell-based Distributed Generation System
Junsheng Jiao
2013-07-01
Full Text Available The dynamic models for the fuel cell power and the configuration of the fuel cell distributed generation system are shown in this paper. Due to nonlinear characteristics of fuel cell model, the output voltage of fuel cell varies greatly when the load changes. A novel interface is designed to provide a constant output voltage for charging of the battery bank of the fuel cell distributed generation. The thesis presents a sliding mode control design of PEMFC distributed generation system. A cascaded control structure is chosen for ease of control realization and to exploit the motion separation property of power converters. The simulation results confirm the output current and voltage of the PEM fuel cell array converge rapidly to their reference values.
Speed Synchronization of Multi Induction Motors with Fuzzy Sliding Mode Control
HACHEMI Glaoui
2013-05-01
Full Text Available A continuous web winding system is a large-scale, complex interconnected dynamic system with numerous tension zones to transport the web while processing it. There are two control schemes for large-scale system control: the centralized scheme and the decentralized scheme. Centralized control is the traditional control method, which considers all the information about the system to be a single dynamic model and design a control system for this model. Aspeed synchronization control strategy for multiple induction motors, based on adjacent cross-coupling control structure, is developed by employing total sliding mode control method. The proposed controlstrategy is to stabilize speed tracking of each induction motor while synchronizing its speed with the speed of the other motors so as to make speed synchronization error amongst induction motors converge to zero. The global stability and the convergence of the designedcontroller are proved by using Lyapunov method. Simulation results demonstrate the effectiveness of the proposed method.
Yang, Jingyu; Lin, Jiahui; Liu, Yuejun; Yang, Kang; Zhou, Lanwei; Chen, Guoping
2016-06-01
It is well known that intelligent control theory has been used in many research fields, novel modeling method (DROMM) is used for flexible rectangular active vibration control, and then the validity of new model is confirmed by comparing finite element model with new model. In this paper, taking advantage of the dynamics of flexible rectangular plate, a two-loop sliding mode (TSM) MIMO approach is introduced for designing multiple-input multiple-output continuous vibration control system, which can overcome uncertainties, disturbances or unstable dynamics. An illustrative example is given in order to show the feasibility of the method. Numerical simulations and experiment confirm the effectiveness of the proposed TSM MIMO controller.
Simulation of a Matrix Converter Fed Drive With Sliding Mode Control
Jan Bauer
2012-01-01
Full Text Available Induction machines are among the most widely used electrical-to-mechanical converters in electric drives. Their advantageous robustness and simplicity goes hand-in-hand with complicated control. A converter with a suitable control algorithm is needed in order to withdraw maximum power and dynamics from the drive. In recent times, control methods such as those based on DTC and sliding mode methods have come to the forefront, due to their robustness and relative simplicity.In the field of power converters, new converter topologies are emerging with improved efficiency that pushes the operation limits of the drive. This paper focuses on the development of a control of this kind of strategy for an induction machine fed from a matrix converter.
Two wheel speed robust sliding mode control for electric vehicle drive
Abdelfatah Nasri
2008-01-01
Full Text Available Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels.
Design a Novel SISO Off-line Tuning of Modified PID Fuzzy Sliding Mode Controller
Ali Shahcheraghi
2014-01-01
Full Text Available The Proportional Integral Derivative (PID Fuzzy Sliding Mode Controller (FSMC is the most widely used control strategy in the Industry (control of robotic arm. The popularity of PID FSMC controllers can be attributed to their robust performance in a wide range of operating conditions and partly to their functional simplicity. The process of setting of PID FSMC controller can be determined as an optimization task. Over the years, use of intelligent strategies for tuning of these controllers has been growing. Biologically inspired evolutionary strategies have gained importance over other strategies because of their consistent performance over wide range of process models and their flexibility. This paper analyses the modified PID FSMC controllers based on minimum rule base for flexible robot manipulator system and test the quality of process control in the simulation environment of MATLAB/SIMULINK Simulator.
A reduced-order nonlinear sliding mode observer for vehicle slip angle and tyre forces
Chen, Yuhang; Ji, Yunfeng; Guo, Konghui
2014-12-01
In this paper, a reduced-order sliding mode observer (RO-SMO) is developed for vehicle state estimation. Several improvements are achieved in this paper. First, the reference model accuracy is improved by considering vehicle load transfers and using a precise nonlinear tyre model 'UniTire'. Second, without the reference model accuracy degraded, the computing burden of the state observer is decreased by a reduced-order approach. Third, nonlinear system damping is integrated into the SMO to speed convergence and reduce chattering. The proposed RO-SMO is evaluated through simulation and experiments based on an in-wheel motor electric vehicle. The results show that the proposed observer accurately predicts the vehicle states.
Sliding mode-based lateral vehicle dynamics control using tyre force measurements
Kunnappillil Madhusudhanan, Anil; Corno, Matteo; Holweg, Edward
2015-11-01
In this work, a lateral vehicle dynamics control based on tyre force measurements is proposed. Most of the lateral vehicle dynamics control schemes are based on yaw rate whereas tyre forces are the most important variables in vehicle dynamics as tyres are the only contact points between the vehicle and road. In the proposed method, active front steering is employed to uniformly distribute the required lateral force among the front left and right tyres. The force distribution is quantified through the tyre utilisation coefficients. In order to address the nonlinearities and uncertainties of the vehicle model, a gain scheduling sliding-mode control technique is used. In addition to stabilising the lateral dynamics, the proposed controller is able to maintain maximum lateral acceleration. The proposed method is tested and validated on a multi-body vehicle simulator.
Impedance Control of the Rehabilitation Robot Based on Sliding Mode Control
Zhou, Jiawang; Zhou, Zude; Ai, Qingsong
As an auxiliary treatment, the 6-DOF parallel robot plays an important role in lower limb rehabilitation. In order to improve the efficiency and flexibility of the lower limb rehabilitation training, this paper studies the impedance controller based on the position control. A nonsingular terminal sliding mode control is developed to ensure the trajectory tracking precision and in contrast to traditional PID control strategy in the inner position loop, the system will be more stable. The stability of the system is proved by Lyapunov function to guarantee the convergence of the control errors. Simulation results validate the effectiveness of the target impedance model and show that the parallel robot can adjust gait trajectory online according to the human-machine interaction force to meet the gait request of patients, and changing the impedance parameters can meet the demands of different stages of rehabilitation training.
Decentralized sliding-mode control for spacecraft attitude synchronization under actuator failures
Wu, Baolin; Wang, Danwei; Poh, Eng Kee
2014-12-01
This paper examines attitude synchronization and tracking problems with model uncertainties, external disturbances, actuator failures and control torque saturation. Two decentralized sliding mode control laws are proposed and analyzed based on algebraic graph theory. Using Barbalat's Lemma, it is shown that the control laws guarantee each spacecraft approaches the desired time-varying attitude and angular velocity while maintaining attitude synchronization among the other spacecraft in the formation. The first controller is designed in the presence of model uncertainties, external disturbances, and actuator failures. The results are extended to the case with control input saturation in the second controller. Both control laws do not require online identification of failures. Numerical simulations are presented to show the effectiveness of the proposed attitude synchronization and tracking approaches.
A novel active vibration isolation system using negative stiffness structure (active system with NSS) for low excitation frequency ranges (< 5 Hz) is developed successfully. Here, the negative stiffness structure (NSS) is used to minimize the attraction of vibration. Then, the fuzzy sliding mode controller (FSMC) is designed to improve the vibration isolation performance of the active system with NSS. Based on Lyapunov stability theorem, the fuzzy control rules are constructed. Next, the experimental apparatus is built for evaluating the isolation efficiency of the proposed system controlled by the FSMC corresponding to various excitation conditions. In addition, the isolation performance of the active system with NSS, the active system without NSS and the passive the system with NSS is compared. The experimental results confirmed that the active system with NSS gives better isolation efficiency than the active system without NSS and the passive system with NSS in low excitation frequency areas
A robust positioning control scheme has been developed using friction parameter observer and recurrent fuzzy neural networks based on the sliding mode control. As a dynamic friction model, the LuGre model is adopted for handling friction compensation because it has been known to capture sufficiently the properties of a nonlinear dynamic friction. A developed friction parameter observer has a simple structure and also well estimates friction parameters of the LuGre friction model. In addition, an approximation method for the system uncertainty is developed using recurrent fuzzy neural networks technology to improve the precision positioning degree. Some simulation and experiment provide the verification on the performance of a proposed robust control scheme
Mingchao Xia
2013-01-01
Full Text Available Control strategies of D-STATCOM for unbalanced load compensation under internal and external disturbances were discussed. Linear control strategies do not have a satisfactory dynamic performance and become invalid under internal or external disturbances. To guarantee a good precision and robustness, a control strategy combining input-output feedback linearization technique with integral sliding mode control (ISMC method was applied to D-STATCOM for unbalanced load compensation. The strategy has features of simple structure and is easy to implement. A 10 MVar/10 kV D-STATCOM simulation system was built in PSCAD/EMTDC to verify the effectiveness and robustness of the control strategy proposed. Simulation results show that the control strategy can compensate reactive power and eliminate unbalance simultaneously under various disturbances.
Sliding mode control for an aerodynamic missile based on backstepping design
Wenjin GU; Hongchao ZHAO; Changpeng PAN
2005-01-01
In order to solve the mismatched uncertainties of a class of nonlinear systems,a control method of sliding mode control (SMC) based on the backstepping design is proposed.It introduces SMC in to the last step of backstepping design to modify the backstepping algorithm.This combination not only enables the generalization of the backstepping design to be applied to more general nonlinear systems,but also makes the SMC method become effective in solving the mismatched uncertainties.The SMC based on the backstepping design is applied to the flight control system design of an aerodynamic missile.The control system is researched through simulation.The simulation results show the effectiveness of the proposed control method.
Cytopathology whole slide images and virtual microscopy adaptive tutorials: A software pilot
Simone L Van Es
2015-01-01
Full Text Available Background: The constant growth in the body of knowledge in medicine requires pathologists and pathology trainees to engage in continuing education. Providing them with equitable access to efficient and effective forms of education in pathology (especially in remote and rural settings is important, but challenging. Methods: We developed three pilot cytopathology virtual microscopy adaptive tutorials (VMATs to explore a novel adaptive E-learning platform (AeLP which can incorporate whole slide images for pathology education. We collected user feedback to further develop this educational material and to subsequently deploy randomized trials in both pathology specialist trainee and also medical student cohorts. Cytopathology whole slide images were first acquired then novel VMATs teaching cytopathology were created using the AeLP, an intelligent tutoring system developed by Smart Sparrow. The pilot was run for Australian pathologists and trainees through the education section of Royal College of Pathologists of Australasia website over a period of 9 months. Feedback on the usability, impact on learning and any technical issues was obtained using 5-point Likert scale items and open-ended feedback in online questionnaires. Results: A total of 181 pathologists and pathology trainees anonymously attempted the three adaptive tutorials, a smaller proportion of whom went on to provide feedback at the end of each tutorial. VMATs were perceived as effective and efficient E-learning tools for pathology education. User feedback was positive. There were no significant technical issues. Conclusion: During this pilot, the user feedback on the educational content and interface and the lack of technical issues were helpful. Large scale trials of similar online cytopathology adaptive tutorials were planned for the future.
Farzin Piltan
2012-06-01
Full Text Available Design a nonlinear controller for second order nonlinear uncertain dynamical systems is one ofthe most important challenging works. This paper focuses on the design, implementation andanalysis of a chattering free sliding mode controller for highly nonlinear dynamic PUMA robotmanipulator and compare to computed torque controller, in presence of uncertainties. In order toprovide high performance nonlinear methodology, sliding mode controller and computed torquecontroller are selected. Pure sliding mode controller and computed torque controller can be usedto control of partly known nonlinear dynamic parameters of robot manipulator. Conversely, puresliding mode controller is used in many applications; it has an important drawback namely;chattering phenomenon which it can causes some problems such as saturation and heat themechanical parts of robot manipulators or drivers. In order to reduce the chattering this researchis used the linear saturation function boundary layer method instead of switching function methodin pure sliding mode controller. These simulation models are developed as a part of a softwarelaboratory to support and enhance graduate/undergraduate robotics courses, nonlinear controlcourses and MATLAB/SIMULINK courses at research and development company (SSP Co.research center, Shiraz, Iran.
Her-Terng Yau
2013-01-01
Full Text Available An extremum seeking control (ESC scheme is proposed for maximum power point tracking (MPPT in photovoltaic power generation systems. The robustness of the proposed scheme toward irradiance changes is enhanced by implementing the ESC scheme using a sliding mode control (SMC law. In the proposed approach, the chattering phenomenon caused by high frequency switching is suppressed by means of a sliding layer concept. Moreover, in implementing the proposed controller, the optimal value of the gain constant is determined using a particle swarm optimization (PSO algorithm. The experimental and simulation results show that the proposed PSO-based sliding mode ESC (SMESC control scheme yields a better transient response, steady-state stability, and robustness than traditional MPPT schemes based on gradient detection methods.
Adaptive Control Using Residual Mode Filters Applied to Wind Turbines
Frost, Susan A.; Balas, Mark J.
2011-01-01
Many dynamic systems containing a large number of modes can benefit from adaptive control techniques, which are well suited to applications that have unknown parameters and poorly known operating conditions. In this paper, we focus on a model reference direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend this adaptive control theory to accommodate problematic modal subsystems of a plant that inhibit the adaptive controller by causing the open-loop plant to be non-minimum phase. We will augment the adaptive controller using a Residual Mode Filter (RMF) to compensate for problematic modal subsystems, thereby allowing the system to satisfy the requirements for the adaptive controller to have guaranteed convergence and bounded gains. We apply these theoretical results to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine that has minimum phase zeros.
Daehyun Kim
2015-11-01
Full Text Available We propose a state-of-charge (SOC estimation method for Li-ion batteries that combines a fuzzy sliding mode observer (FSMO with grey prediction. Unlike the existing methods based on a conventional first-order sliding mode observer (SMO and an adaptive gain SMO, the proposed method eliminates chattering in SOC estimation. In this method, which uses a fuzzy inference system, the gains of the SMO are adjusted according to the predicted future error and present estimation error of the terminal voltage. To forecast the future error value, a one-step-ahead terminal voltage prediction is obtained using a grey predictor. The proposed estimation method is validated through two types of discharge tests (a pulse discharge test and a random discharge test. The SOC estimation results are compared to the results of the conventional first-order SMO-based and the adaptive gain SMO-based methods. The experimental results show that the proposed method not only reduces chattering, but also improves estimation accuracy.
Atabak Kolabi
2013-01-01
Full Text Available This study compares the power system stabilizer based on sliding mode control with the fuzzy power system stabilizer for Single Machine Infinite Bus System (SMIB. Using the sliding mode control, a range is obtained for the changes in system parameters; and a stabilizer is designed to have a proper performance in this wide range. The purpose of designing the sliding mode stabilizer and fuzzy stabilizer is the increased stability and improving the dynamic response of the single machine system connected to the infinite bus in different working conditions. In this study, simulation results are compared in case of conventional PSS, no PSS, PSS based on sliding mode control and PSS based fuzzy logic. The results of simulations performed on the model of nonlinear system shows good performance of sliding mode controller and the Fuzzy controller. SMIB system was selected because of its simple structure, which is very useful in understanding the effects and implications of the PSS.
Adaptive sliding control of non-autonomous active suspension systems with time-varying loadings
Chen, Po-Chang; Huang, An-Chyau
2005-04-01
An adaptive sliding controller is proposed in this paper for controlling a non-autonomous quarter-car suspension system with time-varying loadings. The bound of the car-body loading is assumed to be available. Then, the reference coordinate is placed at the static position under the nominal loading so that the system dynamic equation is derived. Due to spring nonlinearities, the system property becomes asymmetric after coordinate transformation. Besides, in practical cases, system parameters are not easy to be obtained precisely for controller design. Therefore, in this paper, system uncertainties are lumped into two unknown time-varying functions. Since the variation bound of one of the unknown functions is not available, conventional adaptive schemes and robust designs are not applicable. To deal with this problem, the function approximation technique is employed to represent the unknown function as a finite combination of basis functions. The Lyapunov direct method can thus be used to find adaptive laws for updating coefficients in the approximating series and to prove stability of the closed-loop system. Since the position and velocity measurements of the unsprung mass are lumped into the unknown function, there is no need to install sensors on the axle and wheel assembly in the actual implementation. Simulation results are presented to show the performance of the proposed strategy.
Ghanbarian, Mohammad Mehdi; Nayeripour, Majid; Rajaei, Amirhossein; Mansouri, Mohammad Mahdi
2016-03-01
As the output power of a microgrid with renewable energy sources should be regulated based on the grid conditions, using robust controllers to share and balance the power in order to regulate the voltage and frequency of microgrid is critical. Therefore a proper control system is necessary for updating the reference signals and determining the proportion of each inverter in the microgrid control. This paper proposes a new adaptive method which is robust while the conditions are changing. This controller is based on a modified sliding mode controller which provides adapting conditions in linear and nonlinear loads. The performance of the proposed method is validated by representing the simulation results and experimental lab results. PMID:26704720
Keum, Jung-Hoon; Ra, Sung-Woong
2009-12-01
Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.
LQ optimal and reaching law-based sliding modes for inventory management systems
Ignaciuk, Przemysław; Bartoszewicz, Andrzej
2012-01-01
In this article, the theory of discrete sliding-mode control is used to design new supply strategies for periodic-review inventory systems. In the considered systems, the stock used to fulfil an unknown, time-varying demand can be replenished from a single supply source or from multiple suppliers procuring orders with different delays. The proposed strategies guarantee that demand is always entirely satisfied from the on-hand stock (yielding the maximum service level), and the warehouse capacity is not exceeded (which eliminates the cost of emergency storage). In contrast to the classical, stochastic approaches, in this article, we focus on optimising the inventory system dynamics. The parameters of the first control strategy are selected by minimising a quadratic cost functional. Next, it is shown how the system dynamical performance can be improved by applying the concept of a reaching law with the appropriately adjusted reaching phase. The stable, nonoscillatory behaviour of the closed-loop system is demonstrated and the properties of the designed controllers are discussed and strictly proved.
LQ Optimal Sliding Mode Control of Periodic Review Perishable Inventories with Transportation Losses
Piotr Leśniewski
2013-01-01
Full Text Available In this work we apply the control-theoretic approach to design a new replenishment strategy for inventory systems with perishable stock. Such systems are supposed to effectively satisfy an unknown and permanently time-varying consumers’ demand. The main obstacle of achieving this goal is the need of obtaining supplies from a distant source. During the supply process goods are inevitably lost due to various causes. Furthermore, those goods which successfully arrive at the distribution center still deteriorate while stored in its warehouse. We explicitly take into account both of these factors in designing our control strategy. We propose a sliding mode strategy and choose its parameters to minimize a quadratic quality criterion. This approach allows us to ameliorate the bullwhip effect (the amplification of the demand variations when going up in the supply chain. The control strategy proposed in this work ensures bounded orders, guarantees full consumers’ demand satisfaction, and eliminates the risk of exceeding the warehouse capacity. These properties are stated in three theorems and proved in the paper.
Chattering-Free Neuro-Sliding Mode Control of 2-DOF Planar Parallel Manipulators
Tien Dung Le
2013-01-01
Full Text Available This paper proposes a novel chattering free neuro‐sliding mode controller for the trajectory tracking control of two degrees of freedom (DOF parallel manipulators which have a complicated dynamic model, including modelling uncertainties, frictional uncertainties and external disturbances. A feedforward neural network (NN is combined with an error estimator to completely compensate the large nonlinear uncertainties and external disturbances of the parallel manipulators. The online weight tuning algorithms of the NN and the structure of the error estimator are derived with the strict theoretical stability proof of the Lyapunov theorem. The upper bound of uncertainties and the upper bound of the approximation errors are not required to be known in advance in order to guarantee the stability of the closed‐loop system. The example simulation results show the effectiveness of the proposed control strategy for the tracking control of a 2‐DOF parallel manipulator. It results in its being chattering‐free, very small tracking errors and its robustness against uncertainties and external disturbances.
State observer-based sliding mode control for semi-active hydro-pneumatic suspension
Ren, Hongbin; Chen, Sizhong; Zhao, Yuzhuang; Liu, Gang; Yang, Lin
2016-02-01
This paper proposes an improved virtual reference model for semi-active suspension to coordinate the vehicle ride comfort and handling stability. The reference model combines the virtues of sky-hook with ground-hook control logic, and the hybrid coefficient is tuned according to the longitudinal and lateral acceleration so as to improve the vehicle stability especially in high-speed condition. Suspension state observer based on unscented Kalman filter is designed. A sliding mode controller (SMC) is developed to track the states of the reference model. The stability of the SMC strategy is proven by means of Lyapunov function taking into account the nonlinear damper characteristics and sprung mass variation of the vehicle. Finally, the performance of the controller is demonstrated under three typical working conditions: the random road excitation, speed bump road and sharp acceleration and braking. The simulation results indicated that, compared with the traditional passive suspension, the proposed control algorithm can offer a better coordination between vehicle ride comfort and handling stability. This approach provides a viable alternative to costlier active suspension control systems for commercial vehicles.
A sliding-mode-based observer to identify faults in FBG sensors embedded in composite structures
Cazzulani, Gabriele; Cinquemani, Simone; Ronchi, Marco
2016-04-01
Optical strain gauges, such as Fiber Bragg Gratings (FBG), have a great potential for smart structures, thanks to their small transversal size and the possibility to make an array of many sensors. They can be embedded in composite structures and their effect on the structure is nearly negligible. These advantages make them very interesting in the field of active vibration suppression. Unfortunately their low reliability is an obstacle to their use in such applications. For this reason, this paper introduces a fault identification algorithm to identify online those sensors which are not working correctly. The algorithm is based on the use of a sliding mode observer to estimate the coherence of measurements, and then to highlight possible faults. Once identified, the corresponding sensors can be excluded from the feedback loop of the control algorithm to avoid unwanted behaviors or instabilities. Numerical and experimental tests have been carried out on a carbon fiber structure considering different fault conditions. Results show it is possible to identify the faulty sensors and thus improve the signals used in the feedback loop.
Design Sliding Mode Modified Fuzzy Linear Controller with Application to Flexible Robot Manipulator
Mahdi Mirshekaran
2013-11-01
Full Text Available This paper studies the use of Modified Proportional-Integral-Derivative Sliding Mode Controller (MPIDSMC control used to control a flexible manipulator. The control gain in the MPIDSMC controller has been determined in an empirical way so far. It is a considerable time-consuming process because the control performance depends not only on the control gain but also on the other parameters such as the payload, references and PID joint servo gains. Hence, the control gain must be tuned considering the other parameters. In order to find the optimal control gain for the MPIDSMC controller, a fuzzy logic approach is proposed in this paper. The proposed fuzzy logic scheme finds an optimum control gain that minimizes the tip vibration for the end effector of the flexible manipulator. Tuned gain response results are compared to results for other types of gains. The effectiveness of using the fuzzy logic appears in the reduction of the computational time and the ability to tune the gain with different loading condition and input parameters.
A coordinated MIMO control design for a power plant using improved sliding mode controller.
Ataei, Mohammad; Hooshmand, Rahmat-Allah; Samani, Siavash Golmohammadi
2014-03-01
For the participation of the steam power plants in regulating the network frequency, boilers and turbines should be co-ordinately controlled in addition to the base load productions. Lack of coordinated control over boiler-turbine may lead to instability; oscillation in producing power and boiler parameters; reduction in the reliability of the unit; and inflicting thermodynamic tension on devices. This paper proposes a boiler-turbine coordinated multivariable control system based on improved sliding mode controller (ISMC). The system controls two main boiler-turbine parameters i.e., the turbine revolution and superheated steam pressure of the boiler output. For this purpose, a comprehensive model of the system including complete and exact description of the subsystems is extracted. The parameters of this model are determined according to our case study that is the 320MW unit of Islam-Abad power plant in Isfahan/Iran. The ISMC method is simulated on the power plant and its performance is compared with the related real PI (proportional-integral) controllers which have been used in this unit. The simulation results show the capability of the proposed controller system in controlling local network frequency and superheated steam pressure in the presence of load variations and disturbances of boiler. PMID:24112644
IMPLEMENTATION OF MULTILEVEL INVERTER USING MPPT BASED SLIDING MODE CONTROL FOR PV CELL
M.R.Vishnupriya
2013-06-01
Full Text Available In this project photovoltaic array is used as source. The photovoltaic energy is used to feed the inverter through the step up converter. The output for solar module is connected to the battery. So the supply is given continuously by the battery to the system. The output of the solar may vary due to the radiation and will affect the battery. So the lifetime of battery is reduced. It is necessary to protect the battery from the non-linear solar energy, charge controller is used. In order to track maximum power, sliding mode controller is used. In the step up converter a new method is used. The new step-up converter consists of coupled inductor and fixed capacitor. The voltage stress of active switch is being reduced byclamp capacitor. The output of the new topology of dc-dc converter is given to hybrid multilevel inverter which consists of reduced number of switches. The overall system is simulated using MATLAB prototypeof the proposed system is developed and output is verified with simulation results.
Smooth Sliding Mode Control for Vehicle Rollover Prevention Using Active Antiroll Suspension
Duanfeng Chu
2015-01-01
Full Text Available The rollover accidents induced by severe maneuvers are very dangerous and mostly happen to vehicles with elevated center of gravity, such as heavy-duty trucks and pickup trucks. Unfortunately, it is hard for drivers of those vehicles to predict and prevent the trend of the maneuver-induced (untripped rollover ahead of time. In this study, a lateral load transfer ratio which reflects the load distribution of left and right tires is used to indicate the rollover criticality. An antiroll controller is designed with smooth sliding mode control technique for vehicles, in which an active antiroll suspension is installed. A simplified second order roll dynamic model with additive sector bounded uncertainties is used for control design, followed by robust stability analysis. Combined with the vehicle dynamics simulation package TruckSim, MATLAB/Simulink is used for simulating experiment. The results show that the applied controller can improve the roll stability under some typical steering maneuvers, such as Fishhook and J-turn. This direct antiroll control method could be more effective for untripped rollover prevention when driver deceleration or steering is too late. It could also be extended to handle tripped rollovers.
Active following fuzzy output feedback sliding mode control of real-vehicle semi-active suspensions
Liu, H.; Nonami, K.; Hagiwara, T.
2008-07-01
Many semi-active suspension systems have been investigated in various literatures in order to achieve lower energy consumption and as good performance as full-active suspension systems. Full-active suspension systems can achieve a good ride quality by actuators; however, their implementation equipments are expensive. The full-active suspensions are perfect from the point of view of control; hence, semi-active control laws with performance similar to full-active controls have attracted the engineering community for their ease and lower cost of implementation. This paper presents a new active following fuzzy output feedback sliding mode control for a real-vehicle semi-active suspension system. The performance of the proposed controller has been verified by comparing it with passive control and also with the full-active target semi-active approximation control method. In the experiment, it was shown that the proposed method has the effectiveness in stabilizing heave, roll and pitch movement of the car body.
Highlights: • Higher order Sliding Mode Control system has been presented for core power control. • The reactor core has been simulated based on the point kinetics equations. • The model assumes feedback from lumped fuel and coolant temperatures. • The effect of xenon concentration was also included. • The control system is guaranteed to be stable within a large range. - Abstract: Reactor power control is one of the most important problems in a nuclear power plant. This paper presents the higher order sliding mode controller (H.O.S.M.C.) which is a robust nonlinear controller for a nuclear research reactor considering the effect of xenon concentration during load following operation. Sliding mode controllers for nuclear reactors were developed before. Traditional sliding mode technique has intrinsic problem of chattering. To cope with this problem higher order sliding mode (HOSM) is used. The nonlinear model of a research reactor (Pakistan Research Reactor-1) has been used for higher order sliding mode controller design and performance evaluation. The reactor core is simulated based on the point kinetics equations and three delayed neutron groups. The model assumes feedback from lumped fuel and coolant temperatures. The effect of xenon concentration is also included. The employed method is easy to implement in practical applications and moreover, the higher order sliding mode control exhibits the desired dynamic behavior during the entire output-tracking process. Simulation results show the effectiveness of the proposed controller in terms of performance, stability and robustness against disturbances
This paper presents an analysis by which the dynamic performances of a permanent magnet synchronous motor (PMSM) motor is controlled through a hysteresis current loop and an outer speed loop with different controllers. The dynamics of the wind turbine pumping drive system with (PI) and a fuzzy sliding mode (FSM) speed controllers are presented. In order to optimize the overall system efficiency, a maximum power point tracker is also used. Simulation is carried out by formatting the mathematical model for wind turbine generator, motor and pump load. The results for such complicated and nonlinear system, with fuzzy sliding mode speed controller show improvement in transient response of the PMSM drive over conventional PI. The effectiveness of the FSM controller is also demonstrated. (author)
Taizhou Bei
2014-01-01
Full Text Available Considering the disadvantages of the traditional high-gain DC-DC converter such as big size, high voltage stress of switches, and large input current ripple, a novel high-gain interleaved boost converter with coupled-inductor and switched-capacitor was proposed correspondingly and the operation principle together with the steady-state analysis of this converter was also described. Besides, a new control approach-dynamic sliding mode evolution PWM controller (DSME PWM for the novel topological converter based on both dynamic evolution and sliding mode control was also presented. From the simulation results and experimental validation the proposed converter can fulfill high-gain boost, low ripple of both the input current and the output voltage. Furthermore, MPPT technique can be also achieved in a short time by simulation. The efficiency and stability of the converter proposed in this paper can be improved.
Fezzani Amor
2014-01-01
Full Text Available This paper is devoted to the study of the performances of a robust speed sensorless nonlinear control of permanent magnet synchronous machine. In the first part, the controllers are designed using two methods: the first one using the input output feedback linearization control and the second is a nonlinear control based on Lyapunov theory combined with sliding mode control. This second solution shows good robustness with respect to parameter variations, measurement errors and noises. In the second part, the high order sliding mode speed observer is used to overcome the occurring chattering phenomena. The super twisting algorithm is modified in order to design a speed and position observer for PMSM. Finally, simulation results are given to demonstrate the effectiveness and the good performance of the proposed control methods.
Sliding Mode Control of Three Levels Back-To-Back VSC-HVDC System Using Space Vector Modulation
Bouafia Saber
2014-03-01
Full Text Available In this study, a sliding mode strategy proposed to control a three levels Back-to-Back High Voltage Direct Current (HVDC system based on the three-level voltage source converter (VSC. The voltage-balancing control of two split DC capacitors of the VSC-HVDC system is achieved using three-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. Finally, a complete simulation of the VSC-HVDC system validates the efficiency of the proposed strategy law. Compared to the conventional control, Sliding Mode Control scheme for the VSC-HVDC system shows the attractive advantages such as offering high tracking accuracy, fast dynamic response and good robustness.
Zhao Jing
2015-01-01
Full Text Available This paper proposes a strategy of a new optimal sliding-mode control for flight control system with state constraints so that the system guarantees the optimal performance index. Besides, the strategy ensures strong robustness to the internal parametric uncertainty and the external disturbances. In order to have fast transient response speed as well as good tracking accuracy, the integral of the time multiplied by the absolute displacement tracking error is introduced as the performance index. By analyzing the state constraints which are specifically the velocity tracking error constraint and the acceleration tracking error constraint, and the performance index, the parameters of sliding-mode surface and control law are obtained. Finally, the authors conduct the semi physical simulation on Qball-X4 quad-rotor helicopter, showing the effectiveness of the proposed strategy.
Fixed frequency sliding mode-based robust inversion with a full-bridge current DC-link buck-boost
Olm Miras, Josep Maria; Biel Solé, Domingo; Fossas Colet, Enric; Cardoner Parpal, Rafel
2014-01-01
The substitution of the original switches by a full bridge in a Non-Inverting Buck-Boost converter results in an inverter capable of carrying out step-down and step-up tasks as well under sliding mode control. The control law is implemented by means of the Zero Average Dynamics algorithm, which provides a fixed frequency operation and guarantees null error in each switching period, thus achieving a highly accurate tracking of periodic reference profiles. Furthermore, semi-infinite programming...
Galindo, Roberto; Cotoregea Pfeifer, María; Biel Solé, Domingo
2006-01-01
In this paper the authors consider the Sliding Mode Control (SMC) of a Doubly Fed Induction Generator (DFIG), supplying an isolated RL load in a Variable Speed-Constant Frequency (VSCF) generation system. It must be reminded that in electric machines the existence of parameter changes, caused by several reasons like winding temperature variation, hysteresis and saturation, is well recognized, but rarely accounted for. For this reason, SMC has been considered. SMC has various attractive featur...
Kai-Hui Zhao; Te-Fang Chen; Chang-Fan Zhang; Jing He; Gang Huang
2014-01-01
To prevent irreversible demagnetization of a permanent magnet (PM) for interior permanent magnet synchronous motors (IPMSMs) by flux-weakening control, a robust PM flux-linkage nonsingular fast terminal-sliding-mode observer (NFTSMO) is proposed to detect demagnetization faults. First, the IPMSM mathematical model of demagnetization is presented. Second, the construction of the NFTSMO to estimate PM demagnetization faults in IPMSM is described, and a proof of observer stability is given. The ...
Shuanghe Yu; Lina Jin; Kai Zheng; Jialu Du
2013-01-01
Finite-time control scheme for speed regulation of permanent magnet synchronous motor (PMSM) is investigated under the port-controlled Hamiltonian (PCH), terminal sliding mode (TSM), and fast TSM stabilization theories. The desired equilibrium is assigned to the PCH structure model of PMSM by maximum torque per ampere (MTPA) principle, and the desired Hamiltonian function of state error is constructed in the form of fractional power structure as TSM and fast TSM, respectively. Finite-time TSM...
Yeganeh Fallah, Arash; Taghikhany, Touraj
2015-12-01
Recent decades have witnessed much interest in the application of active and semi-active control strategies for seismic protection of civil infrastructures. However, the reliability of these systems is still in doubt as there remains the possibility of malfunctioning of their critical components (i.e. actuators and sensors) during an earthquake. This paper focuses on the application of the sliding mode method due to the inherent robustness of its fault detection observer and fault-tolerant control. The robust sliding mode observer estimates the state of the system and reconstructs the actuators’ faults which are used for calculating a fault distribution matrix. Then the fault-tolerant sliding mode controller reconfigures itself by the fault distribution matrix and accommodates the fault effect on the system. Numerical simulation of a three-story structure with magneto-rheological dampers demonstrates the effectiveness of the proposed fault-tolerant control system. It was shown that the fault-tolerant control system maintains the performance of the structure at an acceptable level in the post-fault case.
Sliding mode control for Lorentz-augmented spacecraft hovering around elliptic orbits
Huang, Xu; Yan, Ye; Zhou, Yang; Zhang, Hua
2014-10-01
A Lorentz spacecraft is an electrostatically charged space vehicle that could actively modulate its surface charge to generate Lorentz force as it moves through the planetary magnetic field. The induced Lorentz force provides propellantless electromagnetic propulsion for orbital maneuvering, such as spacecraft hovering that the chaser thrusts continuously to create an equilibrium state at the desired position relative to the target. Due to the fact that the direction of Lorentz force is determined by the local magnetic field and the velocity of the spacecraft with respect to the local magnetic field, which does not necessarily coincide with that of the required control acceleration for hovering, thus, in most cases, the Lorentz force works as a means of auxiliary propulsion to reduce the expenditure of fuel onboard. And that is why it is called Lorentz-augmented hovering. A dynamical model for Lorentz-augmented hovering around elliptic orbits is developed based upon the assumption that the Earth's magnetic field could be modeled as a tilted dipole that corotates with Earth. Fuel-optimal open-loop control laws are then derived based on the proposed dynamical model, presenting the optimal trajectories of the required specific charge of Lorentz spacecraft and the thruster-generated control acceleration. Considering the external disturbances that may drift the desired hovering position, a closed-loop integral sliding mode controller is also designed to guarantee the tracking of optimal control trajectories, ensuring the robustness of the system against perturbations. Numerical simulations are presented to analyze the characteristics of Lorentz-augmented hovering around eccentric orbits and the results substantiate the validity of the proposed open-loop and closed-loop control methods.
Septian Ainur Rofiq
2014-03-01
Full Text Available Autonomous Underwater Vehicle (AUV merupakan kendaraan bawah air yang dapat bergerak tanpa kendali manusia dan bermanuver sesuai dengan perintah yang diberikan. AUV memiliki kemampuan manuver yang dinamis untuk melacak lintasan. Kemampuan AUV mencakup untuk beroperasi di daerah yang memiliki dinamika nonlinear dan belum dapat diprediksi. Sehingga dibutuhkan model kontrol berbasis nonlinear untuk meningkatkan kemampuan dan misi AUV. Gerak lateral merupakan salah satu bentuk pergerakan AUV di dalam air. AUV dijaga agar tetap stabil pada lintasan dan kedalaman yang dikehendaki. Pengaturan kestabilan AUV di dalam air pada gerak lateral menggunakan metode Sliding Mode Control (SMC diharapkan agar respon yang diperoleh menyerupai input referensi sistem linear orde satu dan tetap stabil pada koordinat lintasan yang telah ditentukan. Hasil simulasi menunjukkan bahwa SMC dapat mempertahankan kestabilan AUV tetap pada lintasan yang telah ditentukan pada 0 radian dengan osilasi maksimal pada lintasan persegi, segitiga dan jajaran genjang sebesar 0,19 radian atau sekitar 10,89 derajat.
Sliding mode control of an autonomous parallel fuel cell-super capacitor power source
More, Jeronimo J. [Universidad Nacional de La Plata (UNLP), La Plata, Buenos Aires (Argentina). Facultad de Ingenieria. Lab. de Electronica Industrial, Control e Instrumentacion], Email: jmore@ing.unlp.edu.ar; Puleston, Paul F. [Consejo de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Kunusch, Cristian; Colomer, Jordi Riera I. [Universitat Politecnica de Catalunya, Barcelona (Spain). Inst. de Robotica i Informatica Industrial (IRII)
2010-07-01
Nowadays, hydrogen fuel cell (FC) based systems emerge as one promising renewable alternative to fossil fuel systems in automotive and residential applications. However, their output dynamic response is relatively slow, mostly due to water and reactant gases dynamics. To overcome this limitation, FC-super capacitors (SCs) topologies can be used. The latter is capable of managing very fast power variations, presenting in addition high power density, long life cycle and good charge/discharge efficiency. In this work, a FC-SCs-based autonomous hybrid system for residential applications is considered. The FC and SCs are connected in parallel, through two separate DC/DC converters, to a DC bus. Under steady state conditions, the FC must deliver the load power requirement, while maintaining the SCs voltage regulated to the desired value. Under sudden load variations, the FC current rate must be limited to assure a safe transition to the new point of operation. During this current rate limitation mode, the SCs must deliver or absorb the power difference. To this end, a sliding mode strategy is proposed to satisfy to control objectives. The main one is the robust regulation of the DC bus voltage, even in the presence of system uncertainties and disturbances, such as load changes and FC voltage variations. Additionally, a second control objective is attained, namely to guarantee the adequate level of charge in the SCs, once the FC reaches the new steady state operation point. In this way, the system can meet the load power demand, even under sudden changes, and it can also satisfy a power demand higher than the nominal FC power, during short periods. The proposed control strategy is evaluated exhaustively by computer simulation considering fast load variations. The results presented in this work, corresponds to the first stage of a R and D collaboration project for the design and development of a novel FC-SCs-based autonomous hybrid system. In the next phase, the proposed
Toda, Masayoshi
2016-01-01
This book provides readers with alternative robust approaches to control design for an important class of systems characteristically associated with ocean-going vessels and structures. These systems, which include crane vessels, on-board cranes, radar gimbals, and a conductivity temperature and depth winch, are modelled as manipulators with oscillating bases. One design approach is based on the H-infinity control framework exploiting an effective combination of PD control, an extended matrix polytope and a robust stability analysis method with a state-dependent coefficient form. The other is based on sliding-mode control using some novel nonlinear sliding surfaces. The model demonstrates how successful motion control can be achieved by suppressing base oscillations and in the presence of uncertainties. This is important not only for ocean engineering systems in which the problems addressed here originate but more generally as a benchmark platform for robust motion control with disturbance rejection. Researche...
Peng Wu; Ming Yang
2010-01-01
Aimed at the guidance requirements of some missiles which attack targets with terminal impact angle at the terminal point,a new integrated guidance and control design scheme based on variable structure control approach for missile with terminal impact angle constraint is proposed.First,a mathematical model of an integrated guidance and control model in pitch plane is established,and then nonlinear transformation is employed to transform the mathematical model into a standard form suitable for sliding mode control method design.A sufficient condition for the existence of linear sliding surface is given in terms of linear matrix inequalities(LMIs),based on which the corresponding reaching motion controller is also developed.To verify the effectiveness of the proposed integrated design scheme,the numerical simulation of missile is made.The simulation results demonstrate that the proposed guidance and control law can guide missile to hit the target with desired impact angle and desired flight attitude angle simultaneously.
Adaptive slope compensation for high bandwidth digital current mode controller
Taeed, Fazel; Nymand, Morten
converter duty cycle. The adaptive slope compensation provides optimum controller operation in term of bandwidth over wide range of operating points. In this paper operation principle of the controller is discussed. The proposed controller is implemented in an FPGA to control a 100 W buck converter. The......An adaptive slope compensation method for digital current mode control of dc-dc converters is proposed in this paper. The compensation slope is used for stabilizing the inner current loop in peak current mode control. In this method, the compensation slope is adapted with the variations in...... experimental results of measured loop-gain at different operating points are presented to validate the theoretical performance of the controller....
Sliding mode Control using 3D-SVM for Three-phase Four-Leg Shunt Active Filter
Bouzidi Mansour
2013-02-01
Full Text Available This paper proposes a sliding mode control strategy for a three-phase shunt active power filter. The SAPF consists of four-leg voltage source inverter bridge. The SAPF ensures full compensation for harmonic phase currents, harmonic neutral current, reactive power compensation and unbalanced nonlinear load currents. The modulation task can be carried out with three dimensional space vector modulation, which operate under a constant switching frequency. The simulation results show that the performance of the four-leg SAPF with the proposed control algorithm – compared with PI controller - is found considerably effective and adequate to compensate harmonics, reactive power, neutral current and balance load currents.
Djemaï, M.; Busawon, K.; Benmansour, K.; Marouf, A.
2011-11-01
In this article, we present a high-order sliding mode controller of a DC motor drive connected to a multi-cellular converter. More specifically, we design a second-order (super-twisting) control algorithm for the speed regulation of a DC motor. For this, a switching control for the multi-cellular converter is derived in order to supply the correct reference value for the speed regulation. A practical implementation of the controller is realised using a laboratory set-up. The performance and the validity of the controller are shown experimentally.
Guowei Cai
2014-01-01
Full Text Available As to strong nonlinearity of doubly fed induction generators (DFIG and uncertainty of its model, a novel rotor current controller with nonlinearity and robustness is proposed to enhance fault ride-though (FRT capacities of grid-connected DFIG. Firstly, the model error, external disturbances, and the uncertain factors were estimated by constructing extended state observer (ESO so as to achieve linearization model, which is compensated dynamically from nonlinear model. And then rotor current controller of DFIG is designed by using terminal sliding mode variable structure control theory (TSMC. The controller has superior dynamic performance and strong robustness. The simulation results show that the proposed control approach is effective.
This paper introduces an indirect intelligent sliding mode controller (IISMC) for shape memory alloy (SMA) actuators, specifically a flexible beam deflected by a single offset SMA tendon. The controller manipulates applied voltage, which alters SMA tendon temperature to track reference bending angles. A hysteretic recurrent neural network (HRNN) captures the nonlinear, hysteretic relationship between SMA temperature and bending angle. The variable structure control strategy provides robustness to model uncertainties and parameter variations, while effectively compensating for system nonlinearities, achieving superior tracking compared to an optimized PI controller. (paper)
Kim, Minsung; Joe, Hangil; Kim, Jinwhan; Yu, Son-cheol
2015-10-01
We propose an integral sliding mode controller (ISMC) to stabilse an autonomous underwater vehicle (AUV) which is subject to modelling errors and often suffers from unknown environmental disturbances. The ISMC is effective in compensating for the uncertainties in the hydrodynamic and hydrostatic parameters of the vehicle and rejecting the unpredictable disturbance effects due to ocean waves, tides and currents. The ISMC is comprised of an equivalent controller and a switching controller to suppress the parameter uncertainties and external disturbances, and its closed-loop system is exponentially stable. Numerical simulations were performed to validate the proposed control approach, and experimental tests using Cyclops AUV were carried out to demonstrate its practical feasibility.
Efﬁcient control of servo pneumatic actuator system utilizing by-pass valve and digital sliding mode
Vladislav Blagojević; Dragan Šešlija; Miodrag Stojiljković; Slobodan Dudić
2013-04-01
The issue of energy saving nowadays is very crucial. Pneumatic systems, constituting an important segment of almost every industry, represent large energy consumers. Also, a signiﬁcant problem with servo pneumatic actuators is achieving accuracy in positioning. The higher the positioning accuracy, the higher the compressed air consumption is. This paper presents a new solution of the positioning control algorithm which uniﬁes digital control of variable structure and sliding working mode and inter chamber cross-ﬂow. The experiments demonstrated that this control algorithm provides a satisfactory positioning accuracy and robustness of the system, simultaneously reducing compressed air consumption by as much as 29.5%.
刘金琨; 尔联洁
2003-01-01
Flight simulator is an important device and a typical high-performance position and speed servo system used in the hardware-in-the-loop simulation of flight control system. Friction is the main nonlinear resistance in the flight simulator servo system, especially in a low-speed state. Based on the description of dynamic and static models of a nonlinear Stribeck friction model, this paper puts forward sliding mode controller to overcome the friction, whose stability is proved. Simulation example indicates that the controller can guarantee a high robust performance and have a high precision of position tracking and speed tracking for a flight simulator servo system.
Huang, Ting; Javaherian, Hossein; Liu, Derong
2011-06-01
This paper presents a new approach for the calibration and control of spark ignition engines using a combination of neural networks and sliding mode control technique. Two parallel neural networks are utilized to realize a neuro-sliding mode control (NSLMC) for self-learning control of automotive engines. The equivalent control and the corrective control terms are the outputs of the neural networks. Instead of using error backpropagation algorithm, the network weights of equivalent control are updated using the Levenberg-Marquardt algorithm. Moreover, a new approach is utilized to update the gain of corrective control. Both modifications of the NSLMC are aimed at improving the transient performance and speed of convergence. Using the data from a test vehicle with a V8 engine, we built neural network models for the engine torque (TRQ) and the air-to-fuel ratio (AFR) dynamics and developed NSLMC controllers to achieve tracking control. The goal of TRQ control and AFR control is to track the commanded values under various operating conditions. From simulation studies, the feasibility and efficiency of the approach are illustrated. For both control problems, excellent tracking performance has been achieved. PMID:21656924
Ebrahimkhani, Sadegh
2016-07-01
Wind power plants have nonlinear dynamics and contain many uncertainties such as unknown nonlinear disturbances and parameter uncertainties. Thus, it is a difficult task to design a robust reliable controller for this system. This paper proposes a novel robust fractional-order sliding mode (FOSM) controller for maximum power point tracking (MPPT) control of doubly fed induction generator (DFIG)-based wind energy conversion system. In order to enhance the robustness of the control system, uncertainties and disturbances are estimated using a fractional order uncertainty estimator. In the proposed method a continuous control strategy is developed to achieve the chattering free fractional order sliding-mode control, and also no knowledge of the uncertainties and disturbances or their bound is assumed. The boundedness and convergence properties of the closed-loop signals are proven using Lyapunov׳s stability theory. Simulation results in the presence of various uncertainties were carried out to evaluate the effectiveness and robustness of the proposed control scheme. PMID:27018145
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
A Real-Time Sliding Mode Control for a Wind Energy System Based on a Doubly Fed Induction Generator
Oscar Barambones
2014-10-01
Full Text Available In this paper, a real time sliding mode control scheme for a variable speed wind turbine that incorporates a doubly feed induction generator is described. In this design, the so-called vector control theory is applied, in order to simplify the system electrical equations. The proposed control scheme involves a low computational cost and therefore can be implemented in real-time applications using a low cost Digital Signal Processor (DSP. The stability analysis of the proposed sliding mode controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory. A new experimental platform has been designed and constructed in order to analyze the real-time performance of the proposed controller in a real system. Finally, the experimental validation carried out in the experimental platform shows; on the one hand that the proposed controller provides high-performance dynamic characteristics, and on the other hand that this scheme is robust with respect to the uncertainties that usually appear in the real systems.
Position control of elevator based on non-singular terminal sliding mode%基于非奇异终端滑模的物料提升机位置控制
姚来鹏; 侯保林
2015-01-01
When implementing different tasks, the servo systems of elevator must adapt to various working loads with different weight or inertia, which may lead to the remarkable variation of system inertial parameters. Due to uncertain inertial parameters, the traditional proportional-integral-differential (PID )control algorithm has poor robustness and cannot achieve high-accuracy position control. A novel nonlinear control scheme is needed to deal with the problem of uncertain inertial parameters. To realize position control with high accuracy and stability for the elevator with uncertain inertial parameters, a control method based on global non-singular terminal sliding mode was proposed for a single-bucket-chain elevator. By adding a nonlinear term to the conventional linear sliding mode surface, the terminal sliding mode could make the system state converge to the sliding surface in finite time. The global non-singular terminal sliding mode technique was used for elevator system to achieve robust stability and guarantee transient response, and the boundary layer control was adopted to avoid chattering introduced by control switching. The stability of the closed-loop system was guaranteed based on the Lyapunov theory. Firstly, the dynamic model of the single-bucket-chain elevator was set up based on the Lagrange method. Secondly, a controller based on global non-singular terminal sliding mode was designed for a single-bucket-chain elevator. Finally, to illustrate the proposed controller with the global non-singular terminal sliding mode had better performances than the continuous feedback controller based on implicit Lyapunov function, numerical simulations had been carried out on the basis of MATLAB/Simulink simulation platform. The position response, speed response and the control input response of hoist part and rotation part were analyzed respectively. The position response results showed that the maximum overshoot by global non-singular terminal sliding mode method
A Study on Mode Confusions in Adaptive Cruise Control Systems
Ahn, Dae Ryong; Yang, Ji Hyun; Lee, Sang Hun [Kookmin University, Seoul (Korea, Republic of)
2015-05-15
Recent development in science and technology has enabled vehicles to be equipped with advanced autonomous functions. ADAS (Advanced Driver Assistance Systems) are examples of such advanced autonomous systems added. Advanced systems have several operational modes and it has been observed that drivers could be unaware of the mode they are in during vehicle operation, which can be a contributing factor of traffic accidents. In this study, possible mode confusions in a simulated environment when vehicles are equipped with an adaptive cruise control system were investigated. The mental model of the system was designed and verified using the formal analysis method. Then, the user interface was designed on the basis of those of the current cruise control systems. A set of human-in-loop experiments was conducted to observe possible mode confusions and redesign the user interface to reduce them. In conclusion, the clarity and transparency of the user interface was proved to be as important as the correctness and compactness of the mental model when reducing mode confusions.
A Study on Mode Confusions in Adaptive Cruise Control Systems
Recent development in science and technology has enabled vehicles to be equipped with advanced autonomous functions. ADAS (Advanced Driver Assistance Systems) are examples of such advanced autonomous systems added. Advanced systems have several operational modes and it has been observed that drivers could be unaware of the mode they are in during vehicle operation, which can be a contributing factor of traffic accidents. In this study, possible mode confusions in a simulated environment when vehicles are equipped with an adaptive cruise control system were investigated. The mental model of the system was designed and verified using the formal analysis method. Then, the user interface was designed on the basis of those of the current cruise control systems. A set of human-in-loop experiments was conducted to observe possible mode confusions and redesign the user interface to reduce them. In conclusion, the clarity and transparency of the user interface was proved to be as important as the correctness and compactness of the mental model when reducing mode confusions
A Guidance Law Based on Terminal Sliding Mode%一种Terminal滑模制导规律研究
张旭; 雷虎民; 曾华; 朱良志
2011-01-01
为拦截高速、大机动目标,建立了纵向平面内的拦截器-目标非线性相对运动学模型,基于Terminal滑模控制中滑模面上的跟踪误差能够在有限时间内收敛到0的思想,设计了纵向平面内的Terminal滑模制导律,并结合Lyapunov稳定性理论对其稳定性进行了证明推导;将继电特性连续化的方法引入到制导律设计中,实现了准滑动模态控制.仿真表明,所设计制导律能使视线角速率在有限时间内收敛到0.该制导律符合动能拦截器可用过载小、燃料受限、对脱靶量要求高等要求,具有一定的工程应用价值.%To intercept high-speed big-maneuvering target,the nonlinear dynamic model of interceptor-target in longitudinal plane was built.Based on the terminal variable-structure control theory in which the tracking error on the sliding mode surface can converge to zero in finite time,the terminal sliding-mode guidance law in longitudinal plane was designed,and the asymptotic stability of guidance system was strictly proven by Lyapunov stability theory.The method of continuing the relay characteristics was introduced to guidance law design,and the law was improved to realize the quasi-sliding mode dynamic control.Simulation results show that the guidance law can make the LOS（line of sight） angular rate converge to zero in finite time.The guidance law can meet the requirements such as kinetic kill vehicle with low overload,limited fuel and small miss-amount,and it offers references for engineering application.
Adityo Yudistira
2014-03-01
Full Text Available Motor induksi tiga fasa banyak digunakan di industri, salah satunya pada industri pabrik gula. Di industri pabrik gula motor industri tiga fasa banyak digunakan pada mesin sentrifugal. Mesin ini digunakan pada proses pemisahan cairan massacuite dan strup hingga didapat kristal gula. Pada proses tersebut terjadi perubahan beban oleh karena itu pada siklus kecepatannya mengalami proses Charging, Spinning dan Discharging. Pengaturan kecepatan motor induksi masih dilakukan secara manual yaitu dengan merubah posisi puli atau ukuran poros dari mesin sentrifugal. Pengaturan dengan metode ini mengakibatkan kecepatan motor akan sulit dikendalikan sesuai dengan yang diharapkan. Pengaturan kecepatan yang tidak tepat juga dapat mengakibatkan hasil produksi gula yang kurang maksimal. Oleh karena itu dibutuhkan metode kontrol untuk mengoptimalkan kecepatan setpoint motor saat mengalami proses Charging, Spinning dan Discharging. Metode kontrol yang digunakan adalah metode Sliding Mode Control. Kontroler SMC yang diimplementasikan pada PLC memiliki W= 10 dan α=0,2. Dari hasil analisa sliding surface diketahui bahwa semakin bertambahnya beban maka hitting time semakin lama. Hasil implementasi kontroler SMC yang digunakan terjadi error ± 6,6% pada kecepatan 300 rpm sedangkan pada kecepatan 800 rpm dan 200 rpm terjadi error ± 2,5%. Sehingga Tugas Akhir ini dapat membantu meningkatkan efisiensi mesin sentrifugal pada pabrik gula.
Huanyin Zhou
2015-07-01
Full Text Available This manuscript presents an improved control algorithm, called Dynamic Sliding Mode Control based on Multiple Models Switching Laws (DSMC-MMSL, for the control of the depth of the studied Autonomous Underwater Vehicle (AUV system, the diving plane controller of which faces disturbances arising from the coupled states. The diving plane model is strongly coupled with the state variables, such as surge speeds and course angles. To achieve the desired dynamic performance, the proposed algorithm consists of two parts: the diving plane control part and the pitch control part, which is used to avoid large pitch angles. Some direct switching control laws are used for the two parts to avoid some impulse phenomena on the control executions. The error-states exponential decay is recommended to eliminate the chattering on the sliding surface. The DSMC-MMSL controller was successfully implemented and experimentally validated with the studied AUV system designed and built by Shenyang Institute of Automation. The results of some lake trials demonstrated that the depth control performances of the AUV system were as desired, and that the AUV system was robust enough for the coupled state variables under the DSMCMMSL algorithm control.
Theerayuth Chatchanayuenyong
2009-01-01
Full Text Available Problem statement: A Sliding Mode Controller (SMC with fast reference voltage generation to correct and regulate unbalance voltage in three-phase system was proposed. Approach: The compensation algorithm was not based on three-symmetrical component decomposition so the controller can yield a fast response that was essential in such a critical real time control work. The reference voltages were fed to the SMC, which was a robust closed loop controller. Results: The proposed algorithm and control scheme of series active filter could correct and regulate unbalance voltage in three-phase system under arbitrary fault conditions of the utility supply. Conclusion: A design example and its simulation results proved the concept and validated the proposed algorithm.
Kai-Hui Zhao
2014-12-01
Full Text Available To prevent irreversible demagnetization of a permanent magnet (PM for interior permanent magnet synchronous motors (IPMSMs by flux-weakening control, a robust PM flux-linkage nonsingular fast terminal-sliding-mode observer (NFTSMO is proposed to detect demagnetization faults. First, the IPMSM mathematical model of demagnetization is presented. Second, the construction of the NFTSMO to estimate PM demagnetization faults in IPMSM is described, and a proof of observer stability is given. The fault decision criteria and fault-processing method are also presented. Finally, the proposed scheme was simulated using MATLAB/Simulink and implemented on the RT-LABplatform. A number of robustness tests have been carried out. The scheme shows good performance in spite of speed fluctuations, torque ripples and the uncertainties of stator resistance.
Highlights: • We present SMC which is a robust nonlinear controller to control the PWR power. • Xenon oscillations are kept bounded within acceptable limits. • The stability analysis has been based on Lyapunov approach. • Simulation results indicate the high performance of this new control. - Abstract: One of the important operations in nuclear power plants is load-following in which imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation considered to be a constraint for the load-following operation. In this paper, sliding mode control (SMC) which is a robust nonlinear controller is designed to control the Pressurized-Water Nuclear Reactor (PWR) power for the load-following operation problem that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO) strategy to maintain xenon oscillations to be bounded. The constant AO is a robust state constraint for load-following problem. The reactor core is simulated based on the two-point nuclear reactor model and one delayed neutron group. The stability analysis is given by means Lyapunov approach, thus the control system is guaranteed to be stable within a large range. The employed method is easy to implement in practical applications and moreover, the sliding mode control exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed controller in terms of performance, robustness and stability. Results show that the proposed controller for the load-following operation is sufficiently effective so that the xenon oscillations are kept bounded in the considered region
Nonlinear mode decomposition: A noise-robust, adaptive decomposition method
Iatsenko, Dmytro; McClintock, Peter V. E.; Stefanovska, Aneta
2015-09-01
The signals emanating from complex systems are usually composed of a mixture of different oscillations which, for a reliable analysis, should be separated from each other and from the inevitable background of noise. Here we introduce an adaptive decomposition tool—nonlinear mode decomposition (NMD)—which decomposes a given signal into a set of physically meaningful oscillations for any wave form, simultaneously removing the noise. NMD is based on the powerful combination of time-frequency analysis techniques—which, together with the adaptive choice of their parameters, make it extremely noise robust—and surrogate data tests used to identify interdependent oscillations and to distinguish deterministic from random activity. We illustrate the application of NMD to both simulated and real signals and demonstrate its qualitative and quantitative superiority over other approaches, such as (ensemble) empirical mode decomposition, Karhunen-Loève expansion, and independent component analysis. We point out that NMD is likely to be applicable and useful in many different areas of research, such as geophysics, finance, and the life sciences. The necessary matlab codes for running NMD are freely available for download.
Adapted G-mode Clustering Method applied to Asteroid Taxonomy
Hasselmann, Pedro H.; Carvano, Jorge M.; Lazzaro, D.
2013-11-01
The original G-mode was a clustering method developed by A. I. Gavrishin in the late 60's for geochemical classification of rocks, but was also applied to asteroid photometry, cosmic rays, lunar sample and planetary science spectroscopy data. In this work, we used an adapted version to classify the asteroid photometry from SDSS Moving Objects Catalog. The method works by identifying normal distributions in a multidimensional space of variables. The identification starts by locating a set of points with smallest mutual distance in the sample, which is a problem when data is not planar. Here we present a modified version of the G-mode algorithm, which was previously written in FORTRAN 77, in Python 2.7 and using NumPy, SciPy and Matplotlib packages. The NumPy was used for array and matrix manipulation and Matplotlib for plot control. The Scipy had a import role in speeding up G-mode, Scipy.spatial.distance.mahalanobis was chosen as distance estimator and Numpy.histogramdd was applied to find the initial seeds from which clusters are going to evolve. Scipy was also used to quickly produce dendrograms showing the distances among clusters. Finally, results for Asteroids Taxonomy and tests for different sample sizes and implementations are presented.
Ryvkin, S.; Chomát, Miroslav
Red Hook, NY: IEEE, 2014, s. 189-192. ISBN 978-1-4799-5816-0. [International Symposium on Electrical Apparatus and Technologies (SIELA 2014) /18./. Bourgas (BG), 29.05.2014-31.05.2014] Institutional support: RVO:61388998 Keywords : input voltage changing * sliding mode control * switch control Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
Ramesh, Tejavathu; Panda, A. K.; Kumar, S. Shiva
2013-08-01
In this research study, the performance of direct torque and flux control induction motor drive (IMD) is presented using five different speed control techniques. The performance of IMD mainly depends on the design of speed controller. The PI speed controller requires precise mathematical model, continuous and appropriate gain values. Therefore, adaptive control based speed controller is desirable to achieve high-performance drive. The sliding-mode speed controller (SMSC) is developed to achieve continuous control of motor speed and torque. Furthermore, the type-1 fuzzy logic speed controller (T1FLSC), type-1 fuzzy SMSC and a new type-2 fuzzy logic speed controller are designed to obtain high performance, dynamic tracking behaviour, speed accuracy and also robustness to parameter variations. The performance of each control technique has been tested for its robustness to parameter uncertainties and load disturbances. The detailed comparison of different control schemes are carried out in a MATALB/Simulink environment at different speed operating conditions, such as, forward and reversal motoring under no-load, load and sudden change in speed.
Field current tracing control of a BSG based on sliding mode current observer%BSG电机励磁电流观测器跟踪控制
余腾伟; 王旭东
2011-01-01
Aiming at the nonlinearities of belt driven starter generator' s (BSG) excitation winding driving circuit and a variety of interference outside the engine compartment, making it difficult for conventional PWM strategy to achieve the optimal output current. According to the sliding mode control theory, a sliding mode observer approach is proposed, and the mathematical module of BSG field windings' driven system is established, utilizing advantages that including good control robustness to conduct online setting. Simulation and experimental results show that the step response time is about 10 ms, and the maximum overshoot is less than 5% . What' s more, the method enhances the systems self adaptive capacity, improves the startup performance of BSG-hybrid cars, and has good current tracking performance, and low costing.%针对弱混合动力汽车中带式驱动启动发电机(BSG)的励磁绕组驱动电路存在的非线性问题,以及发动机舱各种外部干扰导致传统的PWM技术难以使控制电流输出达到最优的问题,依据滑模变结构控制理论,采用电流观测器的方法,建立BSG电机励磁绕组驱动系统的数学模型,给出电流观测器的控制算法,利用滑模变结构控制鲁棒性好的优势对BSG电机励磁电流进行在线整定.仿真和试验结果表明,该方法的阶跃响应时间为10 ms,跟踪电流最大超调小于5％,增强了系统的自适应能力,提高了BSG混合动力轿车启动性能,并且具有较好的电流跟踪效果,降低了成本.
A Novel Sliding Mode Variable Structure Controller Based on a Genetic Algorithm
无
2007-01-01
A novel control method has been proposed by using the genetic algorithm ( GA ) for nonlinear and complex plants. The proposed control strategy is based on a variable structure control, it overcomes the defects of other adaptive methods such as strong dependence to the system. A GA is used to learn to optimally select integral coefficient C. Simulation results verified the effectiveness of the controller. For position control of Direct Current (DC) motor in practice, this method has good performance and strong robustness, and both dynamic and steady performances were improved.
A local cubic smoothing in an adaptation mode
A new approach to a local curve approximation and the smoothing is proposed. The relation between curve points is defined using a special cross-ratio weight functions. The coordinates of three curve points are used as parameters for both the weight functions and the tree-point cubic model (TPS). A very simple in computing and stable to random errors cubic smoother in an adaptation mode (LOCUS) is constructed. The free parameter of TPS is estimated independently of the fixed parameters by recursion with the effective error suppression and can be controlled by the cross-ratio parameters. Efficiency and the noise stability of the algorithm are confirmed by examples and by comparison with other known non-parametric smoothers
Sliding Window Adaptive Constant Modulus Algorithm Based on Complex Hyperbolic Givens Rotations
Abdelouahab, Boudjellal; Abed-Meraim, Karim; Belouchrani, A.; Ravier, Philippe
2013-01-01
This paper proposes a new adaptive Constant Modulus Algorithm (CMA) for the blind separation of communication signals. Although many existing CMA like algorithms have been proposed in the literature, their efﬁciency in terms of convergence rate and separation quality is still relatively low. We introduce here in a new adaptive technique based on the use of complex Hyperbolic Givens rotations which shows very good performance as illustrated by the simulation results and comparative study provi...
Boumediène Allaoua
2013-01-01
Full Text Available The development of electric vehicles power electronics system control comprising of DC-AC inverters and DC-DC converters takes a great interest of researchers in the modern industry. A DC-AC inverter supplies the high power electric vehicle motors torques of the propulsion system and utility loads, whereas a DC-DC converter supplies conventional low-power, low-voltage loads. However, the need for high power bidirectional DC-DC converters in future electric vehicles has led to the development of many new topologies of DC-DC converters. Nonlinear control of power converters is an active area of research in the fields of power electronics. This paper focuses on a fuzzy sliding mode strategy (FSMS as a control strategy for boost DC-DC converter power supply for electric vehicle. The proposed fuzzy controller specifies changes in the control signal based on the surface and the surface change knowledge to satisfy the sliding mode stability and attraction conditions. The performances of the proposed fuzzy sliding controller are compared to those obtained by a classical sliding mode controller. The satisfactory simulation results show the efficiency of the proposed control law which reduces the chattering phenomenon. Moreover, the obtained results prove the robustness of the proposed control law against variation of the load resistance and the input voltage of the studied converter.
李冉; 赵光宙; 徐绍娟
2012-01-01
针对传统滑模观测器在估计电机转速时存在的抖动问题,本文通过永磁同步电机扩展状态方程以及扩展滑模观测器,将滑模控制和模型参考自适应结合在一起,来提取电机转速。从仿真和实验两方面,对新方法与传统滑模观测器方法作了详细的比较,结果验证了新方法可以避免传统滑模参数估计时存在的抖动问题,同时具有良好的动静态性能以及更高的估计精度。%Aiming at the chattering problem arising from the estimation of rotor velocity by using traditional sliding mode observer（SMO）,the paper combines sliding mode control with model reference adaptive systems by the extended state equations of permanent magnet synchronous motor（PMSM） and the equations of extended sliding mode observer of PMSM,and then the new estimation method of rotor velocity is presented.The detailed comparison between the proposed method and the traditional one is introduced according to simulation analysis and experimental validation.The simulation and experimental results show the superiority of the proposed method which avoid the chattering problem of the traditional one and better estimated precision,moreover,good dynamic and static performance are achieved.
Yazan M. Alomari
2015-01-01
Full Text Available Analysis of whole-slide tissue for digital pathology images has been clinically approved to provide a second opinion to pathologists. Localization of focus points from Ki-67-stained histopathology whole-slide tissue microscopic images is considered the first step in the process of proliferation rate estimation. Pathologists use eye pooling or eagle-view techniques to localize the highly stained cell-concentrated regions from the whole slide under microscope, which is called focus-point regions. This procedure leads to a high variety of interpersonal observations and time consuming, tedious work and causes inaccurate findings. The localization of focus-point regions can be addressed as a clustering problem. This paper aims to automate the localization of focus-point regions from whole-slide images using the random patch probabilistic density method. Unlike other clustering methods, random patch probabilistic density method can adaptively localize focus-point regions without predetermining the number of clusters. The proposed method was compared with the k-means and fuzzy c-means clustering methods. Our proposed method achieves a good performance, when the results were evaluated by three expert pathologists. The proposed method achieves an average false-positive rate of 0.84% for the focus-point region localization error. Moreover, regarding RPPD used to localize tissue from whole-slide images, 228 whole-slide images have been tested; 97.3% localization accuracy was achieved.
Chih-Jer Lin
2015-02-01
Full Text Available The purpose of this paper is to investigate the nonlinear friction and compensation for a piezoelectric ceramic ultrasonic motor (USM. Although the architecture of the USM is different from the general electric-mechanical motor, the mathematic model for the USM motor can use the same friction model to formulate the friction phenomenon. To establish the feed-forward controller, the system identification for the USM is needed to study to design the model-based controller. To obtain the optimal system parameters of the USM, PSO and CSS algorithms are studied to identify the system parameters for the nonlinear friction model. For the controller design, a non-model based controller, using back-propagation neural network controller to perform tracking tasks, and the model-based controller, which consists of the feed-forward controller based on the system identification and the sliding-mode control, are discussed in this paper. Finally, the two real-time tracking tasks are used to validate the proposed method.
Urushihara, Shiro; Kamano, Takuya; Yura, Satoshi; Yasuno, Takashi; Suzuki, Takayuki
One of fundamental problems in the factory automation is how to obtain linear motion. Linear motors produce directly the linear motion force without a motion-transform mechanism. Linear d.c. motors (LDMs) have excellent performance and controllability. However, the dynamics of small-sized LDMs is adversely affected by the dead-band due to the friction between brushes and commutators. In this paper, it is described that the design of the two-degree-of-freedom positioning system with a LDM using model reference type sliding mode controller (SMC). The proposed positioning system consists of a fixed gain feedforward controller and a SMC used as a feedback controller. The objective of the SMC is to repress the influence of nonlinear characteristics (the dead-band and parameter variations etc.). The tracking performance can be improved as the fixed gain feedforward controller makes a dynamic inverse system in the feedforward path. The effectiveness of the proposed system for improvement of the tracking performance is demonstrated by experimental results.
Dai, Yanyan; Kim, YoonGu; Wee, SungGil; Lee, DongHa; Lee, SukGyu
2016-01-01
In this paper, the problem of object caging and transporting is considered for multiple mobile robots. With the consideration of minimizing the number of robots and decreasing the rotation of the object, the proper points are calculated and assigned to the multiple mobile robots to allow them to form a symmetric caging formation. The caging formation guarantees that all of the Euclidean distances between any two adjacent robots are smaller than the minimal width of the polygonal object so that the object cannot escape. In order to avoid collision among robots, the parameter of the robots radius is utilized to design the caging formation, and the A⁎ algorithm is used so that mobile robots can move to the proper points. In order to avoid obstacles, the robots and the object are regarded as a rigid body to apply artificial potential field method. The fuzzy sliding mode control method is applied for tracking control of the nonholonomic mobile robots. Finally, the simulation and experimental results show that multiple mobile robots are able to cage and transport the polygonal object to the goal position, avoiding obstacles. PMID:26704719
Li, Boyuan; Du, Haiping; Li, Weihua
2016-05-01
Although electric vehicles with in-wheel motors have been regarded as one of the promising vehicle architectures in recent years, the probability of in-wheel motor fault is still a crucial issue due to the system complexity and large number of control actuators. In this study, a modified sliding mode control (SMC) is applied to achieve fault-tolerant control of electric vehicles with four-wheel-independent-steering (4WIS) and four-wheel-independent-driving (4WID). Unlike in traditional SMC, in this approach the steering geometry is re-arranged according to the location of faulty wheels in the modified SMC. Three SMC control laws for longitudinal velocity control, lateral velocity control and yaw rate control are designed based on specific vehicle motion scenarios. In addition the actuator-grouping SMC method is proposed so that driving actuators are grouped and each group of actuators can be used to achieve the specific control target, which avoids the strong coupling effect between each control target. Simulation results prove that the proposed modified SMC can achieve good vehicle dynamics control performance in normal driving and large steering angle turning scenarios. In addition, the proposed actuator-grouping SMC can solve the coupling effect of different control targets and the control performance is improved.
Adaptive Control of the Chaotic System via Singular System Approach
Yudong Li; Tianyu Zhang; Yujun Zhang
2014-01-01
This paper deals with the control problem of the chaotic system subject to disturbance. The sliding mode surface is designed by singular system approach, and sufficient condition for convergence is given. Then, the adaptive sliding mode controller is designed to make the state arrive at the sliding mode surface in finite time. Finally, Lorenz system is considered as an example to show the effectiveness of the proposed method.
Adaptive Control of the Chaotic System via Singular System Approach
Yudong Li
2014-01-01
Full Text Available This paper deals with the control problem of the chaotic system subject to disturbance. The sliding mode surface is designed by singular system approach, and sufficient condition for convergence is given. Then, the adaptive sliding mode controller is designed to make the state arrive at the sliding mode surface in finite time. Finally, Lorenz system is considered as an example to show the effectiveness of the proposed method.
Li Qin; Fucai Liu; Lihuan Liang
2014-01-01
This paper presents a methodology of the dynamic analysis and control for a novel hybrid humanoid robot arm. The hybrid humanoid robot arm under consideration consists of a spherical parallel manipulator (SPM) connecting two revolute pairs in series form. The dynamic model of the hybrid humanoid robot arm has been set up based on the Lie group and Lie algebra combined with the principle of virtual work, which can avoid the processing of constraint reaction and the division of logic open chain...
Adaptive Backstepping Sliding-Mode Control of the Electronic Throttle System in Modern Automobiles
2014-01-01
In modern automobiles, electronic throttle is a DC-motor-driven valve that regulates air inflow into the vehicle’s combustion system. The electronic throttle is increasingly being used in order to improve the vehicle drivability, fuel economy, and emissions. Electronic throttle system has the nonlinear dynamical characteristics with the unknown disturbance and parameters. At first, the dynamical nonlinear model of the electronic throttle is built in this paper. Based on the model and using th...
Robust and Adaptive Sliding Mode Controller for Machine Tool with Varying Inertia
Bratt, Ola
2006-01-01
This thesis considers the problem of designing a robust controller that achieves highperformance positioning and reference tracking of a machine tool. Specifically, the machine tool is a XY-table used in high-accuracy/high speed milling applications. The XY-table consists of a DC motor drive connected to the load using a ball screw, and can be modelled as a two-mass system. However, the presence of friction and backlash requires nonlinear models and associated control designs. Moreover, the m...
Ming-Chang Pai
2012-01-01
Input shaping technique is widely used in reducing or eliminating residual vibration of flexible structures. The exact elimination of the residual vibration via input shaping technique depends on the amplitudes and instants of impulse application. However, systems always have parameter uncertainties which can lead to performance degradation. In this paper, a closed-loop input shaping control scheme is developed for uncertain flexible structures. The algorithm is based on input shaping control...
Santiesteban, Raul; Floquet, Thierry; Orlov, Yuri; Riachy, Samer; Richard, Jean-Pierre
2008-01-01
Orbital stabilization of an underactuated cart-pendulum system is under study. The quasihomogeneous control synthesis is utilized to design a second order sliding mode controller that drives the actuated cart to a periodic reference orbit in finite time, while the non-actuated pendulum produces bounded oscillations. A modified Van der Pol oscillator is introduced into the synthesis as an asymptotic generator of the periodic motion. The resulting closed-loop system is capable of moving from on...
2015-01-01
This paper proposes an integrated photovoltaic (PV) and proton exchange membrane fuel cell (PEMFC) system for continuous energy harvesting under various operating conditions for use with a brushless DC motor. The proposed scheme is based on the incremental conductance (IncCond) algorithm combined with the sliding mode technique. Under changing atmospheric conditions, the energy conversion efficiency of a PV array is very low, leading to significant power losses. Consequently, increasing effic...
Jui-Ho Chen; Her-Terng Yau; Weir Hung
2014-01-01
This paper proposes a sliding mode extremum seeking control (SMESC) of chaos embedded particle swarm optimization (CEPSO) Algorithm, applied to the design of maximum power point tracking in wind power systems. Its features are that the control parameters in SMESC are optimized by CEPSO, making it unnecessary to change the output power of different wind turbines, the designed in-repetition rate is reduced, and the system control efficiency is increased. The wind power system control is designe...
Bo Yuan Peng; Xueyuan Nie; Ying Chen
2014-01-01
This paper investigates the mechanical response of a coated Ti-6Al-4V alloy surface under different sliding contact stress conditions. The surface was coated with an oxide ceramic material created through the use of a recently developed technique known as plasma electrolytic oxidation (PEO). During the PEO procedure, a composition of silicate and phosphate was used as the electrolyte. In order to evaluate the coating, pin-on-disk (POD) tribology tests and cyclic inclined sliding tests were us...
单Buck逆变器布尔型滑模控制研究%Single Buck inverters based on Boolean sliding mode control
陈江辉; 邓红雷; 王健敏; 谢运祥
2011-01-01
为了提高逆变器滑模控制器的稳态精确度,针对一种由一个双向Buck变换器和桥式换向电路组成的单Buck型逆变器进行类似Lyapunov函数的布尔量滑模控制策略的研究.在其等效电路的状态空间平均法动态模型基础上,建立单Buck型逆变器等效电路的三阶系统数学模型,构建具有电流环节和积分环节的全状态变量滑模切换函数,在此切换函数基础上给出布尔滑模控制器的分析和设计过程.仿真和实验结果表明:系统稳态终值误差小,输出电压和电流具有强鲁棒性和良好动态性能；布尔滑模控制的实际控制律简单,易于实现；验证了所采用布尔滑模控制策略的正确性.%In order to further increase the inverter sliding-mode controller's precision, a Boolean sliding-mode control strategy based on Lyapunov-like function was researched on the single Buck inverter composed of a bi-directional Buck converter and bridge-type diverter. Based on the state space average method dynamic modeling of the system equivalent circuit, third-order system mathematical model of single Buck inverter equivalent circuit and full status sliding manifold with current element and integral element were established. There were operation principles of circuit, circuit dynamic mode and the steps of Boolean sliding-mode controller design. The emulation and experiment show that the system steady-state precision is small. Output voltage and current have strong robustness and a good dynamic performance and Boolean sliding-mode actual control was simple and was to be realized. These results verify the correction of control strategy.
An Adaptive Large Neighborhood Search Algorithm for the Multi-mode RCPSP
Muller, Laurent Flindt
We present an Adaptive Large Neighborhood Search algorithm for the Multi-mode Resource-Constrained Project Scheduling Problem (MRCPSP). We incorporate techniques for deriving additional precedence relations and propose a new method, so-called mode-diminution, for removing modes during execution. ...
Chang Xu
2015-11-01
Full Text Available This paper investigates governor design by reduced-order sliding mode for a hydropower plant with an upstream surge tank. The governing system is made up of a tunnel, a surge tank, a penstock, a wicket gate and servomechanism, a governor, a hydro-turbine and a grid. Concerning the components of the governing system, their mathematic models are established. Then, these models are interconnected to simulate the governing system. From the viewpoint of state space in modern control theory, the governing system is partially observed, which challenges the governor design. By introducing an additional state variable, the control method of reduced-order sliding mode is proposed, where the governor design is based on a reduced-order governing system. Since the governor is applied to the original governing system, the system stability is analyzed by means of the small gain theorem. An genetic algorithm is employed to search a group of parameters of the predefined sliding surface, and a fuzzy inference system is utilized to decrease the chattering problem. Some numerical simulations are illustrated to verify the feasibility and robustness of the control method.
This paper focuses on anti-synchronization for a class of chaotic systems with noise on the basis of the sliding mode control strategy. In order to achieve this target, a proportional integral surface is proposed to simplify the task of assigning the performance of the error system in sliding motion. We use fewer control items but realize a globally and exponentially asymptotical anti-synchronization. Furthermore, three typical examples are presented: a three-dimensional (3D) autonomous chaotic system, a 4D autonomous chaotic system and a 5D non-autonomous chaotic system. Finally, simulation results are demonstrated for multi-dimensional chaotic systems to illustrate the effectiveness of the proposed scheme. (paper)
Akgul, Emre; Mutlu, Mehmet; Saranli, Afsar; Yazicioglu, Yigit
2012-01-01
During the uniform locomotion of compliant legged robots and other terrain vehicles, the body of the robot often exhibits complex oscillations which may have a disturbing effect on onboard sensors. For a camera mounted on such a robot, due to perspective projection, the effects of angular disturbances are particularly pronounced as compared to translational disturbances. This paper is motivated by the particular problem of legged robots exhibiting angular body motions and attempts to evaluate...
Balas, Mark; Frost, Susan
2012-01-01
Flexible structures containing a large number of modes can benefit from adaptive control techniques which are well suited to applications that have unknown modeling parameters and poorly known operating conditions. In this paper, we focus on a direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend our adaptive control theory to accommodate troublesome modal subsystems of a plant that might inhibit the adaptive controller. In some cases the plant does not satisfy the requirements of Almost Strict Positive Realness. Instead, there maybe be a modal subsystem that inhibits this property. This section will present new results for our adaptive control theory. We will modify the adaptive controller with a Residual Mode Filter (RMF) to compensate for the troublesome modal subsystem, or the Q modes. Here we present the theory for adaptive controllers modified by RMFs, with attention to the issue of disturbances propagating through the Q modes. We apply the theoretical results to a flexible structure example to illustrate the behavior with and without the residual mode filter.
Schmidt, Lasse; Andersen, Torben Ole; Pedersen, Henrik C.
2014-01-01
-time convergence properties known from sliding control while at the same time avoiding control chattering, however, on the cost of robustness. Experimental results confirm the announced properties when applied to a hydraulic valve-cylinder drive, and demonstrates superior performance over conventional linear...
N. Ramos-Pedroza
2015-01-01
careful algebraic manipulation in the regulation error system development, along with innovative design of the sliding surface. A detailed model of the UAV LCO dynamics is utilized, and a rigorous analysis is provided to prove asymptotic regulation of the pitching and plunging displacements. Numerical simulation results are provided to demonstrate the performance of the control law.
In this work, a new high-load magnetorheological (MR) fluid mount system is devised and applied to control vibration in a ship engine. In the investigation of vibration-control performance, a new modified indirect fuzzy sliding mode controller is formulated and realized. The design of the proposed MR mount is based on the flow mode of MR fluid, and it includes two separated coils for generating a magnetic field. An optimization process is carried out to achieve maximal damping force under certain design constraints, such as the allowable height of the mount. As an actuating smart fluid, a new plate-like iron-particle-based MR fluid is used, instead of the conventional spherical iron-particle-based MR fluid. After evaluating the field-dependent yield stress of the MR fluid, the field-dependent damping force required to control unwanted vibration in the ship engine is determined. Subsequently, an appropriate-sized MR mount is manufactured and its damping characteristics are evaluated. After confirming the sufficient damping force level of the manufactured MR mount, a medium-sized ship engine mount system consisting of eight MR mounts is established, and its dynamic governing equations are derived. A new modified indirect fuzzy sliding mode controller is then formulated and applied to the engine mount system. The displacement and velocity responses show that the unwanted vibrations of the ship engine system can be effectively controlled in both the axial and radial directions by applying the proposed control methodology. (paper)
A Sliding Mode Control Model of Buying Lotto Lottery%购买乐透彩票的一种滑模控制模型
黄科登
2012-01-01
基于小概率事件原理,建立设置滑模控制并保证实际必然赢利的购买乐透彩票的数学模型.实例分析表明,该模型对乐透彩票游戏的小盘玩法是可行、有效的.%Based on small probability event principle, mathematics model by sliding mode control which canguarantee an actual profit when buying lotto lottery was constructed. Furthermore, the result proves the model is feasible and effectual for small model lotto.
Intelligent manufacture adapts to agile manufacture production mode in the 21st century
Li Xurong
2003-01-01
The paper describes the characteristics of the intelligent manufacturing system and production mode in the21st century in the information age, therefore draws a conclusion that the intelligent manufacturing system adapts to agilemanufacture (AM for short) production mode in the 21 st century.
邹杰; 冯星; 陈谋; 尹卫平
2011-01-01
为了提高飞艇飞行的鲁棒性能,针对飞艇水平面受扰运动提出了一种基于非线性滑模的鲁棒神经网络飞行控制方案.对于飞艇模型中的不确定性,采用神经网络进行逼近,同时对神经网络权值进行在线调整以达到在线逼近的目的.为了有效地处理外部时变干扰对飞艇飞行控制的影响,将参数自适应、神经网络输出与滑模控制相结合设计了飞艇的鲁棒飞行控制.最后,通过飞艇水平面运动控制验证了本文所提出的飞艇鲁棒飞行控制方法的有效性.%The robust neural network flight control scheme is proposed for the plane movement of the airship with disturbance based on the nonlinear sliding mode technology to improve the flight robust performance. The neural networks are used to approximate the uncertainty of the airship model and the weight values are adjusted on line to achieve the approximation. To effectively handle the external disturbance of the airship, the robust flight control is designed combining the parameter adaptation with neural networks and sliding mode control for the airship. Finally, the plane movement control of the airship is executed to demonstrate the feasibility of the proposed robust airship flight control method.
Sliding mode control of an underactuated Quadrotor UAV%欠驱动四旋翼无人飞行器的滑模控制
王璐; 李光春; 王兆龙; 焦斌
2012-01-01
针对六自由度欠驱动四旋翼无人飞行器( Quadrotor UAV)受控模型的复杂非线性问题,提出了一种系统简化方法,并基于简化后的模型设计了滑模控制器,实现了对复杂模型的非线性控制.首先,对Quadrotor UAY模型进行简化处理,从而可将系统解耦为完整驱动部分和欠驱动部分;进而,通过定义一个广义滑动流形实现欠驱动部分的滑模控制器设计;最后,利用Lyapunov理论证明了系统欠驱动部分的稳定性.仿真分析表明,本文提出的控制方法能够有效实现Quadrotor UAV的控制,且与经典PID控制方法相比,具有对外界扰动更强的鲁棒性.%In order to solve the complex nonlinear problem of underactuated quadrotor UAV with six degrees of freedom controllable model, the proposed study focused on the system simplifying method and the sliding mode controller. First, the system model is categorized as a simplified one, allowing the original model decoupled into a fully actuated subsystem and an underactuated subsystem. Secondly, a sliding mode controller of the underactuated subsystem is designed by defining a generalized sliding surface. Lastly, the stability of the underactuated subsystem is validated using Lyspunov theory of stability. Simulation results showed the proposed control scheme enabled the quadrotor UAV to fly effectively when compared with the classical PID control scheme. The proposed study shows a stronger robustness against the disturbance as compared with other studies.
Chen, Qiang; Nan, Yu-Rong; Zheng, Heng-Huo; Ren, Xue-Mei
2015-11-01
A full-order sliding mode control based on a fuzzy extended state observer is proposed to control the uncertain chaos in the permanent magnet synchronous motor. Through a simple coordinate transformation, the chaotic PMSM model is transformed into the Brunovsky canonical form, which is more suitable for the controller design. Based on the fuzzy control theory, a fuzzy extended state observer is developed to estimate the unknown states and uncertainties, and the restriction that all the system states should be completely measurable is avoided. Thereafter, a full-order sliding mode controller is designed to ensure the convergence of all system states without any chattering problem. Comparative simulations show the effectiveness and superior performance of the proposed control method. Project supported by the National Natural Science Foundation of China (Grant Nos. 61403343 and 61433003), the Scientific Research Foundation of Education Department of Zhejiang Province, China (Grant No. Y201329260), and the Natural Science Foundation of Zhejiang University of Technology, China (Grant No. 1301103053408).
Wang Haitao; Dong Xinmin; Xue Jianping; Liu Jiaolong
2014-01-01
Dynamic modeling of a hose-drogue aerial refueling system (HDARS) and an integral sliding mode backstepping controller design for the hose whipping phenomenon (HWP) during probe-drogue coupling are studied. Firstly, a dynamic model of the variable-length hose-drogue assembly is built for the sake of exploiting suppression methods for the whipping phenomenon. Based on the lumped parameter method, the hose is modeled by a series of variable-length links connected with frictionless joints. A set of iterative equations of the hose’s three-dimensional motion is derived subject to hose reeling in/out, tanker motion, gravity, and aerodynamic loads accounting for the effects of steady wind, atmospheric turbulence, and tanker wake. Secondly, relying on a permanent magnet synchronous motor and high-precision position sensors, a new active control strategy for the HWP on the basis of the relative position between the tanker and the receiver is proposed. Considering the strict-feedback configuration of the permanent magnet synchronous motor, a rotor position control law based on the backstepping method is designed to insure global stability. An integral of the rotor position error and an exponential sliding mode reaching law of the current errors are applied to enhance control accuracy and robustness. Finally, the simulation results show the effectiveness of the proposed model and control laws.
Kil To Chong
2013-10-01
Full Text Available The main objective of the present work is to apply a sliding mode controller (SMC to medium voltage and high power output energy recovery Li-ion power accumulator battery pack testing systems (ERLPABTSs, which are composed of a three-level neutral-point-clamped (NPC three-phase voltage source inverter (VSI and a two-level buck-boost converter without an isolating transformer. An inner current decoupled control scheme for the aforementioned system is proposed and two sliding mode planes for active and reactive current control are designed based on the control scheme. An optimized switching table for current convergence is used according to the error sign of the equivalent input voltage and feedback voltage. The proposed ERLPABTS could be used to integrate discharging energy into the power grid when performing high accuracy current testing. The active and reactive power references for the grid-connected inverter are determined based on the discharging energy from the DC-DC converter. Simulations and experiments on a laboratory hardware platform using a 175 kW insulated gate bipolar transistor (IGBT-based ERLPABTS have been implemented and verified, and the performance is found satisfactory and superior to conventional ERLPABPTS.
Zhu, Guang; Zhou, Yu Sheng; Bai, Peng; Meng, Xian Song; Jing, Qingshen; Chen, Jun; Wang, Zhong Lin
2014-06-18
Effectively harvesting ambient mechanical energy is the key for realizing self-powered and autonomous electronics, which addresses limitations of batteries and thus has tremendous applications in sensor networks, wireless devices, and wearable/implantable electronics, etc. Here, a thin-film-based micro-grating triboelectric nanogenerator (MG-TENG) is developed for high-efficiency power generation through conversion of mechanical energy. The shape-adaptive MG-TENG relies on sliding electrification between complementary micro-sized arrays of linear grating, which offers a unique and straightforward solution in harnessing energy from relative sliding motion between surfaces. Operating at a sliding velocity of 10 m/s, a MG-TENG of 60 cm(2) in overall area, 0.2 cm(3) in volume and 0.6 g in weight can deliver an average output power of 3 W (power density of 50 mW cm(-2) and 15 W cm(-3)) at an overall conversion efficiency of ∼ 50%, making it a sufficient power supply to regular electronics, such as light bulbs. The scalable and cost-effective MG-TENG is practically applicable in not only harvesting various mechanical motions but also possibly power generation at a large scale. PMID:24692147
Augmented Adaptive Control of a Wind Turbine in the Presence of Structural Modes
Frost, Susan A.; Balas, Mark J.; Wright, Alan D.
2010-01-01
Wind turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, potentially causing component fatigue and failure. Two key technology drivers for turbine manufacturers are increasing turbine up time and reducing maintenance costs. Since the trend in wind turbine design is towards larger, more flexible turbines with lower frequency structural modes, manufacturers will want to develop methods to operate in the presence of these modes. Accurate models of the dynamic characteristics of new wind turbines are often not available due to the complexity and expense of the modeling task, making wind turbines ideally suited to adaptive control. In this paper, we develop theory for adaptive control with rejection of disturbances in the presence of modes that inhibit the controller. We use this method to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the interference of certain structural modes in feedback. The control objective is accomplished by collectively pitching the turbine blades. The adaptive pitch controller for Region 3 is compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller.
感应电机高阶终端滑模磁链观测器的研究%High-order Terminal Sliding Mode Flux Observer for Induction Motors
史宏宇; 冯勇
2012-01-01
提出了基于高阶非奇异终端滑模的感应电机转子磁链观测方法,用于实现感应电机的按转子磁链定向控制.设计了非奇异终端滑模面及观测器的控制策略,利用所设计的控制策略推导出电机转子磁链信息.为了抑制常规滑模存在的抖振现象,设计了定子电流观测器的高阶滑模控制律,可将控制信号直接用于电机转子磁链的估计.较常规滑模观测器,所提方法具有较高的观测精度,并对电机参数变化具有良好的鲁棒性.仿真结果验证了方法的有效性.%This paper proposes a rotor flux estimation method based on high-order sliding mode and non-singular terminal sliding mode for implementing the field orientation control of induction motors. A nonsingular terminal sliding mode and the control law of the observer are designed. The rotor flux of the motor is deduced using the designed control law. Meanwhile, the high-order sliding mode technique is adopted to eliminate the chattering phenomenon of the conventional sliding mode so that the control signal of the observer can be used directly for rotor flux estimation. Compared to conventional sliding mode observers, the proposed observer can estimate the system state with a higher precision. Further, it is insensitive to parameter variations. Simulation results validate the proposed method.
Jehun Hahm
2015-01-01
Full Text Available This paper proposes an integrated photovoltaic (PV and proton exchange membrane fuel cell (PEMFC system for continuous energy harvesting under various operating conditions for use with a brushless DC motor. The proposed scheme is based on the incremental conductance (IncCond algorithm combined with the sliding mode technique. Under changing atmospheric conditions, the energy conversion efficiency of a PV array is very low, leading to significant power losses. Consequently, increasing efficiency by means of maximum power point tracking (MPPT is particularly important. To manage such a hybrid system, control strategies need to be established to achieve the aim of the distributed system. Firstly, a Matlab/Simulink based model of the PV and PEMFC is developed and validated, as well as the incremental conductance sliding (ICS MPPT technique; then, different MPPT algorithms are employed to control the PV array under nonuniform temperature and insolation conditions, to study these algorithms effectiveness under various operating conditions. Conventional techniques are easy to implement but produce oscillations at MPP. Compared to these techniques, the proposed technique is more efficient; it produces less oscillation at MPP in the steady state and provides more precise tracking.
Mode estimation and adaptive feedforward control for stabilization of a flexible gun tube
Vandegrift, Mark W.; DiRenzo, Michael T.
1998-07-01
In this paper we describe an approach for designing a pointing and stabilization system for an unbalanced, flexible gun. Our approach is based upon classical control techniques as well as system identification and adaptive feedforward techniques. Adaptive algorithms identify the flexible modes of the system and estimate the dynamics unbalance. This information is used to update the control law in order to improve the stabilization accuracy of the system.
Chebabhi Ali
2015-01-01
Full Text Available In this paper, the four leg inverter controlled by the three dimensional space vector modulation (3D SVM is used as the shunt active power filter (SAPF for compensating the three phase four wire electrical network, by using the four leg inverter with 3D SVM advantages to eliminated zero sequence current, fixed switching frequency of inverter switches, and reduced switching losses. This four leg inverter is employed as shunt active power filter to minimizing harmonic currents, reducing magnitude of neutral wire current, eliminating zero sequence current caused by nonlinear single phase loads and compensating reactive power, and a nonlinear sliding mode control technique (SMC is proposed for harmonic currents and DC bus voltage control to improve the performances of the three phase four wire four leg shunt active power filter based on Synchronous Reference Frame (SRF theory in the dq0 axes, and to decoupling the four leg SAPF mathematical model.
Jui-Ho Chen
2014-03-01
Full Text Available This paper proposes a sliding mode extremum seeking control (SMESC of chaos embedded particle swarm optimization (CEPSO Algorithm, applied to the design of maximum power point tracking in wind power systems. Its features are that the control parameters in SMESC are optimized by CEPSO, making it unnecessary to change the output power of different wind turbines, the designed in-repetition rate is reduced, and the system control efficiency is increased. The wind power system control is designed by simulation, in comparison with the traditional wind power control method, and the simulated dynamic response obtained by the SMESC algorithm proposed in this paper is better than the traditional hill-climbing search (HCS and extremum seeking control (ESC algorithms in the transient or steady states, validating the advantages and practicability of the method proposed in this paper.
Ahmed Bourouina
2015-12-01
Full Text Available This paper deals with a variable speed device to produce electrical energy on a power network, based on a doubly-fed induction generator (DFIG supplied by a direct matrix converter used in wind energy conversion systems. In the first place, we carried out briefly a study of modelling on the whole system. In order to control the power flowing between the stator of the DFIG and the power network, a control law is synthesized using three types of controllers: PI, RST and sliding mode controllers. Their respective performances are compared in terms of power reference tracking, response to sudden speed variations, sensitivity to perturbations and robustness against machine parameters variations.
Zhiguo Zhao
2014-01-01
Full Text Available In order to reflect driving intention adequately and improve the launch performance of vehicle equipped with five-speed dry dual clutch transmission (DCT, the issue of coordinating control between engine and clutch is researched, which is based on the DCT and prototype car developed independently. Four-degree-of-freedom (DOF launch dynamics equations are established. Taking advantage of predictive control and genetic algorithm, target tracing curves of engine speed and vehicle velocity are optimally specified. Sliding mode variable structure (SMVS control strategy is designed to track these curves. The rapid prototyping experiment and test are, respectively, conducted on the DCT test bench and in the chassis dynamometer. Results show that the designed SMVS control strategy not only effectively embodies the driver’s intention but also has strong robustness to the vehicle parameter’s variations.
Quick Local Repair Scheme using Adaptive Promiscuous Mode in Mobile Ad Hoc Networks
Joo-Sang Youn
2006-05-01
Full Text Available In mobile ad hoc networks (MANETs, there is frequently disconnected a route consisting of multi- hop from a source to a destination because of the dynamic nature such as the topology change caused by nodes’ mobility. To overcome this situation, existing routing protocols for MANETs have performed route repair scheme to repair the disconnected route. However, existing reactive routing protocols have the problem which is that a source node unnecessarily performs re-discovers the whole path when just one node moves, even if the rest of path needs not to be re-arranged. Therefore, the time for re-discovery of the whole path may often take too long. To solve the problem, we propose a new local repair scheme using promiscuous mode. Our scheme is mainly composed of two parts: adaptive promiscuous mode and quick local repair scheme. Adaptive promiscuous mode is to repeat the switching processes between promiscuous mode and nonpromiscuous mode to overcome energy limit caused by using promiscuous mode in overall time and quick local repair scheme is to fast perform the local re-route discovery process with the information of the active connection in the local area acquired by promiscuous mode. With simulation in the various number of connection, We demonstrate the better network performances achieved with the proposed schemes as compared with AODV as reference model that do not provide local repair scheme.
A Class of Speed-Sensorless Sliding-Mode Observers for High-Performance Induction Motor Drives
Lascu, Christian; Boldea, Ion; Blaabjerg, Frede
2009-01-01
require the rotor speed adaptation, i.e., they are inherently sensorless observers. The most versatile and robust is a dual-reference-frame full-order flux observer. The other two schemes are flux observers implemented in stator frame and rotor frame, respectively. These are simpler than the first one and...
Modified Adaptive Control for Region 3 Operation in the Presence of Wind Turbine Structural Modes
Frost, Susan Alane; Balas, Mark J.; Wright, Alan D.
2010-01-01
Many challenges exist for the operation of wind turbines in an efficient manner that is reliable and avoids component fatigue and failure. Turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, possibly causing component fatigue and failure. Wind turbine manufacturers are highly motivated to reduce component fatigue and failure that can lead to loss of revenue due to turbine down time and maintenance costs. The trend in wind turbine design is toward larger, more flexible turbines that are ideally suited to adaptive control methods due to the complexity and expense required to create accurate models of their dynamic characteristics. In this paper, we design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed horizontal axis wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the excitation of structural modes in the wind turbine. The control objective is accomplished by collectively pitching the turbine blades. The adaptive collective pitch controller for Region 3 was compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller. The adaptive controller will demonstrate the ability to regulate generator speed in Region 3, while accommodating gusts, and reducing the excitation of certain structural modes in the wind turbine.
HOLD MODE BASED DYNAMIC PRIORITY LOAD ADAPTIVE INTERPICONET SCHEDULING FOR BLUETOOTH SCATTERNETS
G.S. Mahalakshmi
2011-09-01
Full Text Available Scheduling in piconets has emerged as a challenging research area. Interpiconet scheduling focuses on when a bridge is switched among various piconets and how a bridge node communicates with the masters in different piconets. This paper proposes an interpiconet scheduling algorithm named, hold mode based dynamic traffic priority load adaptive scheduling. The bridges are adaptively switched between the piconets according to various traffic loads. The main goal is to maximize the utilization of the bridge by reducing the bridge switch wastes, utilize intelligent decision making algorithm, resolve conflict between the masters, and allow negotiation for bridge utilization in HDPLIS using bridge failure-bridge repair procedure . The Hold mode - dynamic traffic - priority based - load adaptive scheduling reduces the number of bridge switch wastes and hence increases the efficiency of the bridge which results in increased performance of the system.
An adaptive quantization method for burst mode synthetic aperture radar data
Joo, T. H.; Held, D. N.
1985-01-01
Synthetic aperture radar (SAR) has high data rate because it collects and processes the data coherently. The data rate limitation of the system has to be satisfied while maintaining good image quality. Thus, a quantizer with minimum data rate and high SNR should be employed. An adaptive quantization method is proposed for the burst mode SAR. This adaptive quantizer uses uniformly quantized data to select a subset of bits which is equivalent to changing the step size of the uniform quantizer. A simple implementation which uses the previous burst data to compute the local statistics for the bit selection is presented. The use of previous burst simplifies the implementation because it does not require storage or delay; however, an abrupt change in the terrain could result in incorrect bit selection. An error analysis of this implementation and comparison of two burst mode SAR images formed using the uniformly quantized and adaptively quantized data is presented.
Sensorless detection technique on fuzzy sliding mode observer for SRM%开关磁阻电机模糊滑模观测器间接位置检测
周永勤; 王旭东; 张玉光; 崔迪
2013-01-01
研究开关磁阻电机滑模观测器间接位置检测方法,针对传统滑模观测器存在抖振影响系统动态性能的问题,引入模糊控制,用模糊控制器调节开关函数的输出幅值,以抑制抖振并快速到达滑模面.详细分析了基于电磁转矩的误差函数构造方法及其选取过程,该误差函数能反映电机转子位置误差与转速误差,讨论了滑模观测器稳定运行条件及参数选取,在此基础上推导了模糊控制规则,设计了模糊滑模观测器.通过仿真和实验分析,验证了模糊滑模观测器能柔化控制器的输出信号,使响应速度更快,且鲁棒性强,可以实现转子位置的精确估算.%A study on indirect detection technique of rotor position based on sliding mode observer for SRM is presented.To solve the problem that the chattering in traditional sliding mode observer will affect the system dynamic performance,the fuzzy control was introduced in sliding mode observer through which the output amplitude of switch function was regulated,so the chattering was suppressed and the sliding mode surface was reached quickly.The construction method and the selection process of error function reflecting the position error and speed error based on electromagnetic torque were analyzed in detail.Then the steady-state operating conditions and parameters selection of sliding mode observer were discussed,on the basis of which the fuzzy control rule was deduced and the design scheme of fuzzy sliding mode observer was also proposed.The simulation and experimental analysis verify that the fuzzy sliding mode observer softens the output signal of controller,make the speed responses faster and the system robustness stronger,and realizes precise estimation of rotor position.
基于准滑模观测器的转子位置精确估计%Precise estimation of rotor position based on quasi-sliding mode observer
王晓明; 王开福
2012-01-01
传统的滑模观测器采用开关函数,开关函数在切换过程中的高频抖动使得转子位置的估计出现一定的误差.通过对永磁同步电机的数学模型分析,提出用饱和函数代替开关函数,使得观测器处于准滑动模态,有效抑制高频抖动.同时,用扩展卡尔曼滤波器代替传统的低通滤波器,一方面进一步提高估计精度,另一方面省去低通滤波后的相位补偿.通过自适应的方式选取边界层的厚度,使得控制增益和抖动维持在最优状态.最后采用SIMULINK 进行仿真,对方案的有效性进行验证.%Switching function is adopted in conventional sliding mode observer (SMO) and a high-frequency jitter takes place in the switching process, so that a definite error occurs to the estimation of rotor position. By analyzing the mathematical model of permanent magnet synchronous Generator(PMSG), a saturation function was proposed to substitute for the switching function. When the saturation function was used, the observer would be in quasi-sliding mode and this could restrain the high-frequency jitter effectively. Meantime, the traditional low-pass filter could be replaced by Extended Kalman filters this on one hand could further increase the estimation accuracy, and on the other hand, could also save the phase compensation after low-pass filtering. In the design of SMO, the boundary layer thickness was selected by u-sing adaptive method, making the control gain and high-frequency jitter keep in an optimal state. Finally, SIMULINK simulation was carried out and the effectiveness of this method was verified with.
Fatma Ben Salem
2014-01-01
Full Text Available This paper is concerned with a framework which unifies direct torque control space vector modulation (DTC-SVM and variable structure control (VSC. The result is a hybrid VSC-DTC-SVM controller design which eliminates several major limitations of the two individual controls and retains merits of both controllers. It has been shown that obtained control laws are very sensitive to variations of the stator resistance, the rotor resistance, and the mutual inductance. This paper discusses the performances of adaptive controllers of VSC-DTC-SVM monitored induction motor drive in a wide speed range and even in the presence of parameters uncertainties and mismatching disturbances. Better estimations of the stator resistance, the rotor resistance, and the mutual inductance yield improvements of induction motor performances using VSC-DTC-SVM, thereby facilitating torque ripple minimization. Simulation results verified the performances of the proposed approach.
Optimized mode-field adapter for low-loss fused fiber bundle signal and pump combiners
Koška, Pavel; Baravets, Yauhen; Peterka, Pavel; Písařík, M.; Bohata, J.
Vol. 9344. BELLINGHAM: SPIE, 2015 - (Ballato, J.; Shaw, L.), 93442I ISBN 978-1-62841-434-9. ISSN 0277-786X. [Conference on Fiber Lasers XII - Technology, Systems, and Applications. San Francisco (US), 09.02.2015-12.02.2015] R&D Projects: GA MPO FR-TI4/734 Institutional support: RVO:67985882 Keywords : Fiber laser * Mode-field adapter * Double clad fiber Subject RIV: BH - Optics, Masers, Lasers
Muawia A. Magzoub
2014-07-01
Full Text Available This study presents the design of a Fuzzy Static (FS and a Fuzzy Dynamic (FD Sliding-Mode Controllers (SMC for both basic and complete ball on beam system. At first, the FSSMC was designed for the simplified and the complete models. Then, the FDSMC was designed on the simplified and the comprehensive models of the system in which the ball is placed on a beam as well. In addition, the lyapunov stability and linearization were used to check the stability of the system. There is an in-built issue of chattering with (FSSMC. However, (FDSMC counter it well. Also, FDSMC is effective with respect to matched disturbance rejection. It has been found out from this research study that the designs of the models which utilize a FDSMC with a comprehensive model of the system were more efficient than the designs that utilize the basic system’s prototype. Lastly, a comprehensive comparative analysis is provided and MATLAB/SIMULINK outcomes confirm the dominance of FDSMC.
A dual mode charge pump with adaptive output used in a class G audio power amplifier
A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented. According to the amplitude of the input signals, the charge pump has two level output voltage rails available to save power. It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation. Also, dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range. The prototype is implemented in 0.18 μm 3.3 V CMOS technology. Experimental results show that the maximum power efficiency of the charge pump is 79.5% - 0.5x mode and 83.6% - 1x mode. The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control. An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results. (semiconductor integrated circuits)
A dual mode charge pump with adaptive output used in a class G audio power amplifier
Yong, Feng; Zhenfei, Peng; Shanshan, Yang; Zhiliang, Hong; Yang, Liu
2011-04-01
A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented. According to the amplitude of the input signals, the charge pump has two level output voltage rails available to save power. It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation. Also, dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range. The prototype is implemented in 0.18 μm 3.3 V CMOS technology. Experimental results show that the maximum power efficiency of the charge pump is 79.5% @ 0.5x mode and 83.6% @ 1x mode. The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control. An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results.
有输入饱和的欠驱动VTOL飞行器滑模控制%Sliding mode control for underactuated VTOL aircraft with input saturation
刘金琨; 龚海生
2013-01-01
垂直起降飞行器(vertical take-off and landing,VTOL)是典型的非线性、欠驱动系统,实际工程中VTOL飞行器的执行机构通常有饱和特性,针对这种模型的特点,对原始数学模型进行了解耦坐标变换,通过可逆坐标变换化成一个最小相位系统和一个非最小相位系统,之后采用滑模设计方法设计控制器.为了解决执行机构的饱和问题,将超出饱和受限的部分回馈到控制器中,构造一个赫尔伍兹稳定的辅助线性系统,然后把它加入到滑模控制器之中,在控制器中做补偿.利用李雅普诺夫函数证明了系统的稳定性.仿真结果表明,此方法可有效地解决输入受限的VTOL飞行器的镇定和轨迹跟踪问题.%Vertical take-off and landing(VTOL) aircraft is a typically nonlinear underactuated system,and its executors usually have saturation characteristics in practical engineering. Firstly, VTOL dynamic e-quation was transformed into two sub-systems by reversible coordination transformations. Secondly, sliding mode controller was designed to realize trajectory tracking, and to compensate for the input saturation , a Hurwitz stable linear auxiliary system was developed and introduced into the sliding surfaces. Finally , the closed-loop system stability was proved by Lyapunov analysis. Simulation results indicate that the proposed method is effective to solve the VTOL aircraft trajectory tracking problem with input saturation.
Output-synchronization for the Different-order Uncertain Chaotic Systems via Fuzzy Sliding Control
Ning Li
2015-07-01
Full Text Available In this study, the synchronization of the outputs for the uncertain chaotic systems with different-orders is presented. An adaptive fuzzy system has been used to approximate the uncertain nonlinear terms. The adaptive fuzzy control strategy is estimated to guarantee output-synchronization of the master-slave chaotic systems based on sliding control theorem. By using a dynamic compensator, the performance of the closed-loop systems in sliding mode is improved. The proposed controller can ensure synchronous error converges to zero. Simulation results are provided to illustrate the effectiveness of the proposed method
Dal, Mehmet; Teodorescu, Remus
2011-01-01
simulations. To demonstrate the effectiveness of each method, several experiments were performed on a DSP-based PM DC motor drive system. Then, the newly proposed combinations of these methods were implemented. The hardware implementation results are comparatively presented and discussed....... reduction techniques are investigated, and the effectiveness of chattering suppression for current regulation of PM DC drives is tested. The sampling rate was also examined to determine how it affects the amplitude of chattering. This paper concentrates on various combinations of observer-based methods in...
张细政; 王耀南
2011-01-01
提出一种结合模糊逻辑与滑模变结构技术的新型风力发电系统鲁棒控制方法,采用级联的风力机滑模控制器和发电机滑模控制器,并利用模糊逻辑实现滑模切换增益的自适应调节。该方法能在定、转子电阻等系统参数具有不确定性的情况下,分别实现对参考转子磁链和转矩的良好控制及对最佳叶片转速的鲁棒跟踪,从而获得在额定发电功率内的最大风能追踪。仿真结果表明,相比较常规的反馈线性化技术,该方法在有参数变化时具有更好的控制性能,鲁棒性更强,具有更高的风能利用率。%A fuzzy-logic-based sliding mode controller is proposed for wind energy conversion system with a variable speed DFIG.The controller is composed of the wind turbine sliding-mode controller and the DFIG sliding-mode controller.The turbine controller is used to achieve a robust tracking of the optimal blade rotor speed to optimize the wind energy capturing,and the DFIG controller is applied to ensure a robust tracking of both the generator torque and the rotor flux.The switching gains of the sliding modes are adapted based on the fuzzy interference system.The global controller is tested and validated on a flexible wind turbine simulator,and the results show that the proposed scheme has better performance and higher wind-energy-utilization ratio than the conventional feeback linearization method in presence of parameter variations.
Satish K. Sharma
2012-01-01
Full Text Available Parabolic symmetric and offset reflector antennas adaptively illuminated using a novel triple-mode feedhorn (TE11+TM01+TE21 with different mode combinations and impedance and radiation performances are presented. The combination of the radiating modes in a feedhorn with proper amplitude and fixed phase values helps in electronically pointing the main beam of the radiating patterns such as that obtained in a beam-steering antenna with limited beam-scan range. This type of radiation performance virtually creates a displaced phase center location for the feedhorn, which, consequently, adaptively illuminates the reflector antenna surface. Impedance-matching bandwidths are preserved for both reflector antennas similar to the case of feedhorn alone. The copolarization gain and peak cross-polarization levels are far better with the offset reflector antenna than the symmetric reflector antenna. Such reflector antennas find applications in ground moving target indicator (GMTI and space based radars. The investigation results are solely computed using FEKO full-wave analysis tool.
王志; 吴红芳
2011-01-01
The Stratospheric airship has the characteristics of nonlinear and slowly time-varying parameters, etc. It also affected by the gusts and atmospheric turbulence in endurance, so the backstepping sliding mode technique is used to implement the robust attitude control of the airship and ensure the system to stability. To avoid the inherent chattering in variable structure control,the self- recurrent wavelet neural networks (SRWNN) are employed to adjust the size of the switch gain in real time. The self - recurrent elements of SRWNN can overcome the oscillation properties of wavelet functions, making estimation more smooth. Digital simulation results show that the controller can adapt to the change of structural parameters of the airship and the impact of external disturbances,and make the system get strong robustness and good dynamic performance.%平流层飞艇具有非线性、参数慢时变等特征,在滞空期间,还受到阵风及大气紊流的影响.将反推滑模技术用于实现飞艇姿态的鲁棒控制,保证了系统稳定.为避免变结构控制中固有的抖振现象,使用自回归小波神经网络(Self-Recurrent Wavelet Neural Networks,SRWNN)实时调整开关增益的大小,网络的自回归单元可以克服小波函数的振荡特性,使得估计更为平滑.仿真结果表明:控制器能够适应飞艇结构参数变化及外部扰动的影响,获得强的鲁棒性与好的动态性能.
带落角约束的滑模变结构制导律研究%On Sliding Mode Variable Structure Guidance Law with Terminal Angular Constraint
张亚松; 任宏光; 吴震; 吴彤薇
2012-01-01
针对某些制导武器命中目标时的落角指标要求,设计了带落角约束的制导律.基于变结构理论和Lyapunov稳定性理论推导了一种末端带落角约束的滑模变结构制导律,并证明了其稳定性；然后,将该制导律和优化的姿态角约束比例导引律进行了数字仿真比较.结果表明,在攻击地面固定目标时,带落角约束的滑模变结构制导律在保证命中目标的同时满足期望的落角,验证了其制导效果.%Considering that the terminal falling angle of some guidance weapons was required to be controlled, a guidance law with terminal angular constraint was designed. The sliding mode variable structure guidance law with terminal angular constraint was designed based on variable structure theory and Lyapunov stability theory, and its stability was proved. Then the digital simulation result of it was compared with that of the proportional guidance law of terminal angular constraint. It showed that the guidance law proposed here can satisfy the demanded impact angle while hitting a target, and the effect of guidance law was validated.
基于滑模观测器的永磁同步电机无传感器矢量控制%Sensorless vector control of PMSM based on sliding mode observer
黄雷; 崔迎
2012-01-01
为解决永磁同步电机(PMSM)控制中机械式位置传感器带来的成本及可靠性等问题,将滑模观测器技术应用到PMSM矢量控制系统中.该系统采用滑模面及滑模等效控制方法,通过选择足够大的滑模增益,在观测电流和实测电流之间的误差上构建滑模面,对电机反电势进行观测以得到转子位置角,并基于Lyapunov稳定性判据对滑模观测器的收敛性进行了分析;建立了应用滑模观测器的PMSM无传感器矢量控制实验系统,设计了位置及速度滑模控制器.进行了1 500r/min稳态及正负转速切换的角度估算实验,实验结果验证了该方法的有效性.研究结果表明,基于滑模观测器的无传感器控制策略能准确估计出PMSM的转子位置角,从而得到转子速度,且系统具有较好的动、静态特性.%In order to eliminate the problems of cost and reliability that caused by the mechanical sensor of the permanent magnet synchronous motor(PMSM) drives, a novel nonlinear control strategy based on sliding mode observer was investigated. The sliding surface was defined on the errors between the actual and estimated currents. The estimated back-EMF was observed to calculate the angle and speed of the rotor by using a sufficient sliding gain. The stypticity of sliding observer based on Lyapunov was analyzed. The hardware and software of the proposed sensorless vector control based on sliding mode observer was implemented. The steady state of 1 500 r/min and the transient response of positive to negative speed tests were evaluated. The experimental results show that proposed sliding mode observer algorithm is effective to estimate the rotor position of the PMSM and has good steady and transient response.
Chen, Yangkang
2016-07-01
The seislet transform has been demonstrated to have a better compression performance for seismic data compared with other well-known sparsity promoting transforms, thus it can be used to remove random noise by simply applying a thresholding operator in the seislet domain. Since the seislet transform compresses the seismic data along the local structures, the seislet thresholding can be viewed as a simple structural filtering approach. Because of the dependence on a precise local slope estimation, the seislet transform usually suffers from low compression ratio and high reconstruction error for seismic profiles that have dip conflicts. In order to remove the limitation of seislet thresholding in dealing with conflicting-dip data, I propose a dip-separated filtering strategy. In this method, I first use an adaptive empirical mode decomposition based dip filter to separate the seismic data into several dip bands (5 or 6). Next, I apply seislet thresholding to each separated dip component to remove random noise. Then I combine all the denoised components to form the final denoised data. Compared with other dip filters, the empirical mode decomposition based dip filter is data-adaptive. One only needs to specify the number of dip components to be separated. Both complicated synthetic and field data examples show superior performance of my proposed approach than the traditional alternatives. The dip-separated structural filtering is not limited to seislet thresholding, and can also be extended to all those methods that require slope information.
Chen, Yangkang
2016-04-01
The seislet transform has been demonstrated to have a better compression performance for seismic data compared with other well-known sparsity promoting transforms, thus it can be used to remove random noise by simply applying a thresholding operator in the seislet domain. Since the seislet transform compresses the seismic data along the local structures, the seislet thresholding can be viewed as a simple structural filtering approach. Because of the dependence on a precise local slope estimation, the seislet transform usually suffers from low compression ratio and high reconstruction error for seismic profiles that have dip conflicts. In order to remove the limitation of seislet thresholding in dealing with conflicting-dip data, I propose a dip-separated filtering strategy. In this method, I first use an adaptive empirical mode decomposition based dip filter to separate the seismic data into several dip bands (5 or 6). Next, I apply seislet thresholding to each separated dip component to remove random noise. Then I combine all the denoised components to form the final denoised data. Compared with other dip filters, the empirical mode decomposition based dip filter is data-adaptive. One only need to specify the number of dip components to be separated. Both complicated synthetic and field data examples show superior performance of my proposed approach than the traditional alternatives. The dip-separated structural filtering is not limited to seislet thresholding, and can also be extended to all those methods that require slope information.
LiQiang Jin
2014-01-01
Full Text Available An adaptive slid mode controller was established for improving the handling stability of motorized electric vehicle (MEV. First and foremost, the structure and advantages of electric vehicle driven by in-wheel motors will be provided. Then, an ideal cornering model of vehicles will be brought and analyzed, after which a method to estimate side-slip angle was also proposed and three typical sensors were used in the theory. Besides, an idea for the recognition of road adhesion coefficient was derived based on MEV platform, which will be helpful for better control performances. Finally, the scheme of control method was given and some typical tests for observing handling properties were implemented based on Simulink and Carsim software. With the outcomes from the experiments, which vividly showed the merits of the controller, one can come to a conclusion that MEV that equips with the adaptive slid mode controller always enjoys better handling performances than the one without control. Furthermore, the controller researched is friendly to the real-time working conditions, which will hold practical values in the future.
Finite element model for linear-elastic mixed mode loading using adaptive mesh strategy
无
2008-01-01
An adaptive mesh finite element model has been developed to predict the crack propagation direction as well as to calculate the stress intensity factors (SIFs), under linear-elastic assumption for mixed mode loading application. The finite element mesh is generated using the advancing front method. In order to suit the requirements of the fracture analysis, the generation of the background mesh and the construction of singular elements have been added to the developed program. The adaptive remeshing process is carried out based on the posteriori stress error norm scheme to obtain an optimal mesh. Previous works of the authors have proposed techniques for adaptive mesh generation of 2D cracked models. Facilitated by the singular elements, the displacement extrapolation technique is employed to calculate the SIF. The fracture is modeled by the splitting node approach and the trajectory follows the successive linear extensions of each crack increment. The SIFs values for two different case studies were estimated and validated by direct comparisons with other researchers work.
Adaptive Control of Non-Minimum Phase Modal Systems Using Residual Mode Filters2. Parts 1 and 2
Balas, Mark J.; Frost, Susan
2011-01-01
Many dynamic systems containing a large number of modes can benefit from adaptive control techniques, which are well suited to applications that have unknown parameters and poorly known operating conditions. In this paper, we focus on a direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend this adaptive control theory to accommodate problematic modal subsystems of a plant that inhibit the adaptive controller by causing the open-loop plant to be non-minimum phase. We will modify the adaptive controller with a Residual Mode Filter (RMF) to compensate for problematic modal subsystems, thereby allowing the system to satisfy the requirements for the adaptive controller to have guaranteed convergence and bounded gains. This paper will be divided into two parts. Here in Part I we will review the basic adaptive control approach and introduce the primary ideas. In Part II, we will present the RMF methodology and complete the proofs of all our results. Also, we will apply the above theoretical results to a simple flexible structure example to illustrate the behavior with and without the residual mode filter.
Hemakom, Apit; Goverdovsky, Valentin; Looney, David; Mandic, Danilo P
2016-04-13
An extension to multivariate empirical mode decomposition (MEMD), termed adaptive-projection intrinsically transformed MEMD (APIT-MEMD), is proposed to cater for power imbalances and inter-channel correlations in real-world multichannel data. It is shown that the APIT-MEMD exhibits similar or better performance than MEMD for a large number of projection vectors, whereas it outperforms MEMD for the critical case of a small number of projection vectors within the sifting algorithm. We also employ the noise-assisted APIT-MEMD within our proposed intrinsic multiscale analysis framework and illustrate the advantages of such an approach in notoriously noise-dominated cooperative brain-computer interface (BCI) based on the steady-state visual evoked potentials and the P300 responses. Finally, we show that for a joint cognitive BCI task, the proposed intrinsic multiscale analysis framework improves system performance in terms of the information transfer rate. PMID:26953174
Yang, Wenxian; Tavner, P. J.
2009-04-01
The Fourier transform (FT) has been the most popular method for analyzing large rotating machine shaft vibration problems, but it assumes that these vibration signals are linear and stationary. However, in reality this is not always true. Nonlinear and non-stationary shaft vibration signals are often encountered during the start-up and shut-down processes of the machines. Additionally, mechanical faults, for example rotor-to-stator rubbing, fluid excitation, part-loosening, and shaft cracking, are nonlinear. Owing to these reasons, an accurate analysis of shaft vibration cannot always be achieved by using the FT. An alternative tool, the wavelet transform (WT), is now being used to improve the situation. But the efficiency is a problem especially when applying the WT to the accurate analysis of a large-scale, lengthy data. In view of the powerful capability of empirical mode decomposition (EMD) to process nonlinear/non-stationary signals, its algorithm efficiency and its satisfactory performance in minimizing energy leakage, the EMD is used in this paper to analyze the problem, the signals investigated are adaptively decomposed into a finite number of intrinsic mode functions (IMFs). The principal IMFs, identified using an energy-distribution threshold, dominate the signals' oscillation. So, 'purified' shaft vibration signals can be reconstructed from these principal IMFs. To remove interference present in principal IMFs, an adaptive band-pass filter is designed, whose central frequency is automatically set to the frequency dominating the IMF being investigated. To facilitate the observation of transient shaft vibration, a transient shaft orbit (TSO) is constructed by introducing timescale into the orbit drawing process. Nine mathematical criteria are also proposed to evaluate the shaft vibrations exhibited in the IMFs and TSOs. The novelty of this approach is that the EMD provides an adaptive, effective, and efficient way to obtain 'purified' shaft vibration
Decentralized direct adaptive neural network control for a class of interconnected systems
Zhang Tianping; Mei Jiandong
2006-01-01
The problem of direct adaptive neural network control for a class of large-scale systems with unknown function control gains and the high-order interconnections is studied in this paper. Based on the principle of sliding mode control and the approximation capability of multilayer neural networks, a design scheme of decentralized direct adaptive sliding mode controller is proposed. The plant dynamic uncertainty and modeling errors are adaptively compensated by adjusted the weights and sliding mode gains on-line for each subsystem using only local information. According to the Lyapunov method, the closed-loop adaptive control system is proven to be globally stable, with tracking errors converging to a neighborhood of zero. Simulation results demonstrate the effectiveness of the proposed approach.
苏建敏; 董云峰
2011-01-01
电磁卫星编队位置跟踪是存在输入延时和扰动不确定的控制问题,以卫星相对运动CW方程作为动力学模型,采用前馈加反馈的方式控制编队运动跟踪预定轨迹,前馈控制量由预定轨迹结合CW方程给出,反馈控制采用状态线性变换后的滑模变结构控制律.证明了滑模切换面可达以及滑模面上的运动与不确定扰动无关.数值仿真表明考虑时滞的控制相比未考虑时滞的控制,位置跟踪精度有所提高.%Electromagnetic satellite formation station-tracking is a control problem with input delay and disturbance uncertainties. Taking CW equation as dynamics model. a control law including feed-forward plus feedback is used for the Station tracking. The feed-forward control quantity is calculated based on the predetermined trajectory and the CW equation.The feedback control adopts sliding mode variable structure control law with state linear transformation. It is proved that sliding manifolds are reachable and sliding mode movement is independent of disturbance uncertainties. Numerical simulation shows that the position tracking with input delay considered is more accurate than that with input delay ignored.
王武
2013-01-01
In view of problem of bad stability of wind energy conversion system based on linear constant controller caused by stochastic volatility of wind speed,the paper proposed a design scheme of wind energy conversion system of permanent magnet synchronous generator based on sliding-mode control.It analyzed building principle of model of wind turbine,model of driving device and model of permanent magnet synchronous generator in the system,and introduced implementation of sliding-mode control strategy.The simulation result shows that the system has good speed tracking characteristic to realize maximum wind energy capturing.%针对由于风速的随机波动性而使基于线性定常控制器的风能转换系统稳定性较差的问题,提出了一种基于滑模控制的永磁同步发电机风能转换系统的设计方案；分析了该系统中风力机模型、传动装置模型和永磁同步发电机模型的建立原理,介绍了滑模控制策略的具体实现.仿真结果表明,该系统具有较好的速度跟踪特性,实现了最大风能捕获.
刘文秀
2011-01-01
应用滑动模态控制（Sliding mode control,SMC）对直线一级倒立摆的稳摆控制进行研究.首先以稳定性理论为基础,采用Ackermann公式设计切换函数.然后分别采用指数趋近律、幂次函数及饱和函数设计控制律.经过MATLAB的仿真结果表明,采用饱和函数sat（s）和幂次函数设计控制律时,控制器的输出、切换函数、倒立摆系统的状态变量均不存在抖振现象,系统表现出了良好的动态品质.%It makes a study of the application of sliding mode control in stabilizing control of linear level inverted pendulum.Firstly this article uses the Ackermann formula to design switching function which based on stability theory.Then it uses exponential velocity trending law,power trending law and saturated function design control law.After the MATLAB simulation,the results show using saturated function sat（s） and power function design control law that the output of the controller,the switch function,inverted pendulum system state variables are not exist the chattering phenomena,and the system shows good dynamic quality.
An Analysis of Fundamental Waffle Mode in Early AEOS Adaptive Optics Images
Makidon, R B; Perrin, M D; Roberts, L C; Soummer, R; Oppenheimer, B R; Graham, J R
2005-01-01
Adaptive optics (AO) systems have significantly improved astronomical imaging capabilities over the last decade, and are revolutionizing the kinds of science possible with 4-5m class ground-based telescopes. A thorough understanding of AO system performance at the telescope can enable new frontiers of science as observations push AO systems to their performance limits. We look at recent advances with wave front reconstruction (WFR) on the Advanced Electro-Optical System (AEOS) 3.6 m telescope to show how progress made in improving WFR can be measured directly in improved science images. We describe how a "waffle mode" wave front error (which is not sensed by a Fried geometry Shack-Hartmann wave front sensor) affects the AO point-spread function (PSF). We model details of AEOS AO to simulate a PSF which matches the actual AO PSF in the I-band, and show that while the older observed AEOS PSF contained several times more waffle error than expected, improved WFR techniques noticeably improve AEOS AO performance. ...
A synchronous buck DC—DC converter with an adaptive multi-mode controller is proposed. In order to achieve high efficiency over its entire load range, pulse-width modulation (PWM), pulse-skip modulation (PSM) and pulse-frequency modulation (PFM) modes were integrated in the proposed DC—DC converter. With a highly accurate current sensor and a dynamic mode controller on chip, the converter can dynamically change among PWM, PSM and PFM control according to the load requirements. In addition, to avoid power device damage caused by inrush current at the start up state, a soft-start circuit is presented to suppress the inrush current. Furthermore, an adaptive slope compensation (SC) technique is proposed to stabilize the current programmed PWM controller for duty cycle passes over 50%, and improve the degraded load capability due to traditional slope compensation. The buck converter chip was simulated and manufactured under a 0.35 μm standard CMOS process. Experimental results show that the chip can achieve 79% to 91% efficiency over the load range of 0.1 to 1000 mA (semiconductor integrated circuits)
朱晓虹; 张广明; 梅磊; 韩世东; 孙明山
2016-01-01
针对传统永磁同步电机( PMSM)矢量控制系统中易受机械式传感器影响的问题,设计了一套基于扩展卡尔曼滤波器( EKF)的PMSM无传感器控制系统;同时由于负载突变和系统参数变化会影响整个控制系统的稳定性,提出一种滑模控制器( SMC)来取代传统PI 速度控制器. 首先对PMSM数学模型进行线性化处理,在此基础上引入EKF算法实现转速、位置的在线估计,并且设计以转速误差作为状态变量的滑模速度控制器,实现速度环的闭环调节. 仿真结果表明,EKF可以有效地对转子速度、位置进行估算,且在滑模速度控制器的作用下系统响应更快、抗干扰性能更好、鲁棒性更强.%A method based on extended kalman filter( EKF) of permanent synchronous motor without position sensor was proposed due to the mechanical sensor problem exiting in traditional PMSM vector control system. At the same time varying load and parameter variations also affect the stability of the whole control system, so a sliding mode controller was used to replace the traditional PI controller. At first, linearizing mathematical model of PMSM,then using extended Kalman filtering algorithm to estimate speed and position, at last, designing speed error as the state variables of the sliding mode speed controller to realize closed-loop control. The simulation results showed that the EKF could estimate the rotor speed and position effectively and system has faster response、better anti-interference performance and stronger robustness under the action of sliding mode speed controller.
肖甘; 黄勤陆
2014-01-01
In this paper , a novel flux sliding mode observer was presented , which based on linear flux model of interior permanent-magnet synchronous motor , the state variables are stator current and linear flux , this observer can extract the position information from estimated flux and realize speed sensorless control.The de-viation between actual and reconstructing current was used to build the switching surface of sliding mode ob -server , and then got the equivalent control signal into linear flux model by the feedback matrix.Use the filte-ring features of flux error equation to eliminate chattering component , the estimated flux has a high sine de-gree.Using phase-locked loop frequency tracking characteristics , extract rotor position angle and speed in-formation from the estimated flux.Compared with traditional electromotive force sliding mode observer , the novel flux observer don′t need low-pass filter , and improved the precision of position identification , has fas-ter dynamic response.Simulation and experiment verify the effectiveness of the proposed control method.%本文根据内置式永磁同步电动机（ IPMSM）的线性磁链模型，以定子电流和线性磁链为状态变量构建磁链滑模观测器，用于从观测磁链中提取位置信息实现无速度传感器控制。观测器中用实际电流与重构电流偏差构建滑模切换面，将得到的等效控制信号经反馈矩阵引入线性磁链模型中，利用磁链误差方程的滤波特性消除抖振分量，得到正弦度高的观测磁链。然后利用锁相环的频率跟踪特性，从磁链观测值中提取转子位置角及转速信息。与传统反电动势滑模观测器相比，无需低通滤波器，提高了位置辨识精度，具有更快的动态响应。仿真和实验验证了该控制方法的有效性。
3-AMINOPROPYLTRIETHOXYSILANE TREATED SLIDES
sprotocols
2014-01-01
Author: University of Nottingham Medical School Division of Histopathy ### METHOD: 1. Wash glass slides in detergent for 30 minutes. - Wash glass slides in running tap water for 30 minutes. - Wash glass slides in distilled water 2x5 minutes. - Wash glass slides in 95% alcohol 2x5 minutes. - Air dry for 10 minutes. - Immerse slides in a freshly prepared 2% solution for 3-aminopropyltriethoxysilane in dry acetone for 5 seconds. - Wash briefly in distilled water twi...
The use of the chatter mode in self-adaptive systems
Yasui, S.
1970-01-01
Chatter mode is used advantageously if the ideal model dynamics is described by a switching function, the chatter mode is reached quickly and then sustained, the chatter frequency is reduced, and any zero in the plant transfer function is cancelled.
Adaptive synchronization control of coupled chaotic neurons in an external electrical stimulation
In this paper we present a combined algorithm for the synchronization control of two gap junction coupled chaotic FitzHugh—Nagumo (FHN) neurons in an external electrical stimulation. The controller consists of a combination of dynamical sliding mode control and adaptive backstepping control. The combined algorithm yields an adaptive dynamical sliding mode control law which has the advantage over static sliding mode-based controllers of being chattering-free, i.e., a sufficiently smooth control input signal is generated. It is shown that the proposed control scheme can not only compensate for the system uncertainty, but also guarantee the stability of the synchronized error system. In addition, numerical simulations are also performed to demonstrate the effectiveness of the proposed adaptive controller. (interdisciplinary physics and related areas of science and technology)
Adaptive synchronization control of coupled chaotic neurons in an external electrical stimulation
Yu Hai-Tao; Wang Jiang; Deng Bin; Wei Xi-Le; Chen Ying-Yuan
2013-01-01
In this paper we present a combined algorithm for the synchronization control of two gap junction coupled chaotic FitzHugh-Nagumo (FHN) neurons in an external electrical stimulation.The controller consists of a combination of dynamical sliding mode control and adaptive backstepping control.The combined algorithm yields an adaptive dynamical sliding mode control law which has the advantage over static sliding mode-based controllers of being chattering-free,i.e.,a sufficiently smooth control input signal is generated.It is shown that the proposed control scheme can not only compensate for the system uncertainty,but also guarantee the stability of the synchronized error system.In addition,numerical simulations are also performed to demonstrate the effectiveness of the proposed adaptive controller.
Rock Slide Risk Assessment: A Semi-Quantitative Approach
Duzgun, H. S. B.
2009-04-01
Rock slides can be better managed by systematic risk assessments. Any risk assessment methodology for rock slides involves identification of rock slide risk components, which are hazard, elements at risk and vulnerability. For a quantitative/semi-quantitative risk assessment for rock slides, a mathematical value the risk has to be computed and evaluated. The quantitative evaluation of risk for rock slides enables comparison of the computed risk with the risk of other natural and/or human-made hazards and providing better decision support and easier communication for the decision makers. A quantitative/semi-quantitative risk assessment procedure involves: Danger Identification, Hazard Assessment, Elements at Risk Identification, Vulnerability Assessment, Risk computation, Risk Evaluation. On the other hand, the steps of this procedure require adaptation of existing or development of new implementation methods depending on the type of landslide, data availability, investigation scale and nature of consequences. In study, a generic semi-quantitative risk assessment (SQRA) procedure for rock slides is proposed. The procedure has five consecutive stages: Data collection and analyses, hazard assessment, analyses of elements at risk and vulnerability and risk assessment. The implementation of the procedure for a single rock slide case is illustrated for a rock slope in Norway. Rock slides from mountain Ramnefjell to lake Loen are considered to be one of the major geohazards in Norway. Lake Loen is located in the inner part of Nordfjord in Western Norway. Ramnefjell Mountain is heavily jointed leading to formation of vertical rock slices with height between 400-450 m and width between 7-10 m. These slices threaten the settlements around Loen Valley and tourists visiting the fjord during summer season, as the released slides have potential of creating tsunami. In the past, several rock slides had been recorded from the Mountain Ramnefjell between 1905 and 1950. Among them
A novel sliding mode observer based on sensorless control for PMSM%基于改进型滑模观测器的永磁同步电机控制
刘超
2012-01-01
Due to the chattering problem existing in traditional sliding mode observers, a novel sensorless control strategy for a permanent magnet synchronous motor ( PMSM) based on traditional sliding mode observer (SMO) was proposed to estimate the rotor position and speed. The sign function was replaced by Sigmoid function to eliminate the chattering. The low pass filter ( LPF) and the theta compensation were also removed. It simplifies the system structure and makes the wave form smooth and accurate. So the precision of the rotor speed and position estimation can be improved. A simulation model of the control system was established through the Matlab/Simulink platform. The simulation results demonstrate that this novel method can reduce the chattering of the system, thus improving the system performance.%传统基于反电动势的滑模观测器采用Sign函数来作为开关函数,因为Sign函数的开关特性,使系统存在抖振大的问题.在传统滑模观测器的基础上,通过采用Sigmoid函数代替Sign函数,改善了开关特性,大大地减少了抖振,并去掉了滤波器和转角补偿器,简化了系统,提高了反电动势的估算精度,从而得到更精确的转速和转角位置信息.在Matlab/Simulink平台基础上建立控制系统仿真模型,对该方案做了验证.仿真结果表明:该方法提高了滑模观测器的精度,降低了系统的抖振,提高了系统的性能.
赵玉壮; 陈思忠
2011-01-01
以提高平顺性为目的,针对油气悬架整车设计了以天棚阻尼为参考模型的滑模控制系统,对4个悬架的阻尼力分别进行控制,建立了非线性半主动油气悬架的七自由度整车模型,使被控车辆振动响应能够跟随参考模型.在Matlab环境中对滑模控制系统的性能进行了验证,仿真车辆以54 km/h的速度行驶于D级路面,与被动油气悬架相比,模型参考滑模控制系统能够有效衰减簧载质量的垂向振动、俯仰振动和侧倾振动.结果表明,基于油气悬架整车的模型参考滑模控制系统对路面激励和车辆参数变化具有较强的鲁棒性,适合应用于非线性油气悬架阻尼控制.%A 7-DOF nonlinear full vehicle model with semi-active hydro-pneumatic suspension was established. Aiming to improve the ride comfort ability, a sliding mode controller with sky-hook reference model was designed based on the nonlinear full vehicle model. The damping force on each suspension unit was controlled individually by the controller so that the responses of the controlled vehicle could follow those of the reference model. The performance of the designed controller was validated in the Matlab simulation environment. The simulated vehicle was subjected to a class-D road profile at 54 km/h. Simulation results show that, compared with passive suspension, the sliding model controller can effectively decrease the vertical, pitch and roll vibration of the sprung mass. The model reference sliding mode control has a strong robustness on road disturbance and parameter variety, and it is eligible for the nonlinear hydropneumatic suspension control.
PT-symmetric microring lasers: Self-adapting broadband mode-selective resonators
Hodaei, Hossein; Heinrich, Matthias; Christodoulides, Demetrios N; Khajavikhan, Mercedeh
2014-01-01
We demonstrate experimentally that stable single longitudinal mode operation can be readily achieved in PT-symmetric arrangements of coupled microring resonators. Whereas any active resonator is in principle capable of displaying single-wavelength operation, selective breaking of PT-symmetry can be utilized to systematically enhance the maximum achievable gain of this mode, even if a large number of competing longitudinal or transverse resonator modes fall within the amplification bandwidth of the inhomogeneously broadened active medium. This concept is robust with respect to fabrication tolerances, and its mode selectivity is established without the need for additional components or specifically designed filters. Our results may pave the way for a new generation of versatile cavities lasing at a desired longitudinal resonance. Along these lines, traditionally highly multi-moded microring resonator configurations can be fashioned to suppress all but one longitudinal mode.
P. Siricharuanun
2016-01-01
Full Text Available A second-order sliding mode control for chaotic synchronization with bounded disturbance is studied. A robust finite-time controller is designed based on super twisting algorithm which is a popular second-order sliding mode control technique. The proposed controller is designed by combining an adaptive law with super twisting algorithm. New results based on adaptive super twisting control for the synchronization of identical Qi three-dimensional four-wing chaotic system are presented. The finite-time convergence of synchronization is ensured by using Lyapunov stability theory. The simulations results show the usefulness of the developed control method.
Jian Fu; Liangming Wang; Mou Chen; Sijiang Chang
2015-01-01
A robust adaptive backstepping attitude control scheme, combined with invariant-set-based sliding mode control and fast-nonlinear disturbance observer, is proposed for the airbreathing hypersonic vehicle with attitude constraints and propulsive disturbance. Based on the positive invariant set and backstepping method, an innovative sliding surface is firstly developed for the attitude constraints. And the propulsive disturbance of airbreathing hypersonic vehicle is described as a differential ...
An adaptive two-stage energy-efficiency mechanism for the doze mode in EPON
Nikoukar, AliAkbar; Hwang, I.-Shyan; Su, Yu-Min; Liem, Andrew Tanny
2016-07-01
Sleep and doze power-saving modes are the common ways to reduce power consumption of optical network units (ONUs) in Ethernet passive optical network (EPON). The doze mode turns off the ONU transmitter when there is no traffic in the upstream direction while the sleep mode turns off the ONU transmitter and receiver. As the result, the sleep mode is more efficient compared to the doze mode, but it introduces additional complexity of scheduling and signaling, losses the clock synchronization and requires long clock recovery time; furthermore, it requires the cooperation of the optical line terminal (OLT) in the downstream direction to queue frames. To improve the energy-saving in the doze mode, a new two-stage mechanism is introduced that the doze sleep duration is extended for longer time with acceptable quality-of-services (QoS) metrics when ONU is idle in the current cycle. By this way the ONU enters the doze mode even in the high load traffic; moreover, the green dynamic bandwidth allocation (GBA) is proposed to calculate the doze sleep duration based on the ONU queue state and incoming traffic ratio. Simulation results show that the proposed mechanism significantly improves the energy-saving 74% and 54% when traffic load is from the light load to the high load in different traffic situations, and also promises the QoS performance.
郑连清; 鲁思男; 申滔; 陆治国
2013-01-01
In order to analyze fast-scale nonlinear phenomenon in Boost PFC in peak-current control mode, a discrete iterative map for Boost PFC converter was derived, and the expression of the state transition matrix was obtained according to this map. In addition, the bifurcation boundary of the system was also derived. Then the simulation was presented to show the intermittent bifurcations and chaos phenomenon of the inductor current in one input voltage cycle. To avoid bifurcations, a double integral sliding mode control was adopted to make the system operate stably in single-period state. Compared with slope compensation, a conclusion can be drawn that double integral sliding mode control can achieve good robustness without imposing external disturbance, and avoid bifurcations caused by variation of the input voltage effectively, which can also attain high power factor (PF) with simple algorithm. The new method is easy to realize and can provide reference for bifurcation control in PFC converters.%为了分析峰值电流型Boost PFC(power factor correction)在快时标下的非线性现象,建立Boost PFC变换器的离散迭代映射,并基于此映射推导其状态转移矩阵的表达式,得到系统分岔的条件,通过仿真观察系统电感电流在输入电压周期内出现的间歇性分岔和混沌现象.为了避免分岔,使系统稳定工作在单周期态,采用双积分滑模的控制方法.仿真结果表明:与常规的斜坡补偿法相比,双积分滑模法不需要施加外部扰动,且具有良好的鲁棒性,在有效地避免因输入电压变化所产生的分岔现象的同时,让Boost PFC具有较高的功率因数(PF),且算法简单,易于实现,对PFC变换器的分岔控制提供了借鉴.
Moreno Eguilaz, Juan Manuel; Salehi Arashloo Arashloo, Ramin
2015-01-01
The voltage-source inverters (VSI) supplying a motor drive are prone to open transistor faults. To address this issue in faulttolerant drives applicable to electric vehicles, a new open transistor fault diagnosis (FD) method is presented in this paper. According to the proposed method, in order to define the FD index, the phase angle of the converter output current is estimated by a simple trigonometric function. The proposed FD method is adaptable, simple, capable of detecting multiple open ...
Abdellah, Skoudarli; Mokhtar, Nibouche; Amina, Serir
2015-11-01
The H.264/AVC video coding standard is used in a wide range of applications from video conferencing to high-definition television according to its high compression efficiency. This efficiency is mainly acquired from the newly allowed prediction schemes including variable block modes. However, these schemes require a high complexity to select the optimal mode. Consequently, complexity reduction in the H.264/AVC encoder has recently become a very challenging task in the video compression domain, especially when implementing the encoder in real-time applications. Fast mode decision algorithms play an important role in reducing the overall complexity of the encoder. In this paper, we propose an adaptive fast intermode algorithm based on motion activity, temporal stationarity, and spatial homogeneity. This algorithm predicts the motion activity of the current macroblock from its neighboring blocks and identifies temporal stationary regions and spatially homogeneous regions using adaptive threshold values based on content video features. Extensive experimental work has been done in high profile, and results show that the proposed source-coding algorithm effectively reduces the computational complexity by 53.18% on average compared with the reference software encoder, while maintaining the high-coding efficiency of H.264/AVC by incurring only 0.097 dB in total peak signal-to-noise ratio and 0.228% increment on the total bit rate.
Xue, Xiaoming; Zhou, Jianzhong; Xu, Yanhe; Zhu, Wenlong; Li, Chaoshun
2015-10-01
Ensemble empirical mode decomposition (EEMD) represents a significant improvement over the original empirical mode decomposition (EMD) method for eliminating the mode mixing problem. However, the added white noises generate some tough problems including the high computational cost, the determination of the two critical parameters (the amplitude of the added white noise and the number of ensemble trials), and the contamination of the residue noise in the signal reconstruction. To solve these problems, an adaptively fast EEMD (AFEEMD) method combined with complementary EEMD (CEEMD) is proposed in this paper. In the proposed method, the two critical parameters are respectively fixed as 0.01 times standard deviation of the original signal and two ensemble trials. Instead, the upper frequency limit of the added white noise is the key parameter which needs to be prescribed beforehand. Unlike the original EEMD method, only two high-frequency white noises are added to the signal to be investigated with anti-phase in AFEEMD. Furthermore, an index termed relative root-mean-square error is employed for the adaptive selection of the proper upper frequency limit of the added white noises. Simulation test and vibration signals based fault diagnosis of rolling element bearing under different fault types are utilized to demonstrate the feasibility and effectiveness of the proposed method. The analysis results indicate that the AFEEMD method represents a sound improvement over the original EEMD method, and has strong practicability.
Trotter, Meredith V; Weissman, Daniel B; Peterson, Grant I; Peck, Kayla M; Masel, Joanna
2014-12-01
The existence of complex (multiple-step) genetic adaptations that are "irreducible" (i.e., all partial combinations are less fit than the original genotype) is one of the longest standing problems in evolutionary biology. In standard genetics parlance, these adaptations require the crossing of a wide adaptive valley of deleterious intermediate stages. Here, we demonstrate, using a simple model, that evolution can cross wide valleys to produce "irreducibly complex" adaptations by making use of previously cryptic mutations. When revealed by an evolutionary capacitor, previously cryptic mutants have higher initial frequencies than do new mutations, bringing them closer to a valley-crossing saddle in allele frequency space. Moreover, simple combinatorics implies an enormous number of candidate combinations exist within available cryptic genetic variation. We model the dynamics of crossing of a wide adaptive valley after a capacitance event using both numerical simulations and analytical approximations. Although individual valley crossing events become less likely as valleys widen, by taking the combinatorics of genotype space into account, we see that revealing cryptic variation can cause the frequent evolution of complex adaptations. PMID:25178652
Microgrid Stability Controller Based on Adaptive Robust Total SMC
Xiaoling Su; Minxiao Han; Josep M. Guerrero; Hai Sun
2015-01-01
This paper presents a microgrid stability controller (MSC) in order to provide existing distributed generation units (DGs) the additional functionality of working in islanding mode without changing their control strategies in grid-connected mode and to enhance the stability of the microgrid. Microgrid operating characteristics and mathematical models of the MSC indicate that the system is inherently nonlinear and time-variable. Therefore, this paper proposes an adaptive robust total sliding...
Farup, Jean
2014-01-01
SUMMARY Human skeletal muscle has a remarkable capability of adapting to a change in demands. The preservation of this adaptability relies partly on a pool of resident myogenic stem cells (satellite cells, SCs). Extrinsic factors such as mechanical load (e.g. resistance exercise) and dietary...... supplementation on human skeletal muscle satellite cell content and muscle cell growth. The aim of paper III was to investigate the fiber type specific SC and myonuclei content, as well as myofiber CSA in response to the 12 weeks Ecc or Conc resistance exercise training combined with Whey or Placebo...... protein constitute key factors in regulation of human skeletal muscle mass; however, the influence of divergent resistance exercise contraction modes and protein supplementation on SC content, is not well described. The overall aim of the present thesis was to investigate whether eccentric versus...
Che, Jiaxing; Cao, Chengyu; Gregory, Irene M.
2012-01-01
This paper explores application of adaptive control architecture to a light, high-aspect ratio, flexible aircraft configuration that exhibits strong rigid body/flexible mode coupling. Specifically, an L(sub 1) adaptive output feedback controller is developed for a semi-span wind tunnel model capable of motion. The wind tunnel mount allows the semi-span model to translate vertically and pitch at the wing root, resulting in better simulation of an aircraft s rigid body motion. The control objective is to design a pitch control with altitude hold while suppressing body freedom flutter. The controller is an output feedback nominal controller (LQG) augmented by an L(sub 1) adaptive loop. A modification to the L(sub 1) output feedback is proposed to make it more suitable for flexible structures. The new control law relaxes the required bounds on the unmatched uncertainty and allows dependence on the state as well as time, i.e. a more general unmatched nonlinearity. The paper presents controller development and simulated performance responses. Simulation is conducted by using full state flexible wing models derived from test data at 10 different dynamic pressure conditions. An L(sub 1) adaptive output feedback controller is designed for a single test point and is then applied to all the test cases. The simulation results show that the L(sub 1) augmented controller can stabilize and meet the performance requirements for all 10 test conditions ranging from 30 psf to 130 psf dynamic pressure.
林海; 严卫生; 王银涛; 李铭峰; 吴涛
2009-01-01
Aim. To solve the problems that sensorless vector control is difficult to implement and that the parameters of normal PI (proportional integral) control cannot be adjusted on-line in the conventional motor control, we propose a novel control method. Sections 2 and 3 of the full paper explain in some detail our novel control method. Its core consists of: (1) we design a variable structure sliding-mode speed controller and a variable structure sliding-mode current controller to replace the traditional speed PI controller and two current PI controllers; (2) we design the unscented Kalman filter (UKF) observer to estimate direct-axis current, quadrature-axis current, load torque, rotor position and speed simultaneously. Section 4 presents simulation results and their analysis. The simulation results, given in Figs. 3 through 5, and their analysis show preliminarily that: (1) the variable structure sliding-mode controllers designed by us can effectively regulate the rotational speed and the current of the IPMSM; (2) the UKF observer we designed can accurately estimate motor states and is robust against perturbation, exterior disturbance and measurement error.%针对电机控制中采用的PI调节器对电机参数变化及外加干扰时鲁棒差和无位置传感器控制实现困难等问题,在研究常规永磁同步电机矢量控制策略的基础上,将滑模变结构控制(VSSMC)和无迹卡尔曼滤波(UKF)引入该策略中,用VSSMC分别替代策略中速度PI控制器和2个PI电流控制器,同时利用UKF对电机定子直轴电流、交轴电流、负载转矩、转子位置和转速进行实时估计,提出了一种新颖的基于VSSMC和UKF的永磁同步电机无传感器矢量控制方案.仿真结果验证了新方案的正确性,所设计的VSSMC能有效调节转速和电流,其调节效果优于常规PI控制器,所设计的UKF观测器能准确估计系统状态,而且两者对系统参数摄动、外干扰、测量误差以及测量噪声都
孙文; 王三民; 任涛
2014-01-01
A new mode swing crank-slide bar beam pumping unit which has been awarded a national patent composes of motor ,re-ducer,crank,slider,guide rod,frame and wire rope.Up and down stroke is performed by slider moving along guide rod guide ap-paratus resulting guide rod up and down movement against supporting point of pumping frame .Crank automatically adjusts torque according to the changes of hanging point loading when slider moves along guide rod .This maintains the net torque of brace axis always at its best condition .The net torque curve is very smooth and uneven loading factor CLF value approaches one .The new mode swing crank-slide bar beam pumping unit dramatically decreases electromotor installed power and obviously improves the evenness of electromotor output power .%一种已经获得国家发明专利授权的新型摆动导杆式抽油机由电动机、减速器、曲柄、滑块、摆动导杆、机架和钢绳等构成，通过曲柄上的滑块在导杆导轨上的滑动，带动导杆以机架为支点做上下摆动，从而实现抽油机的上下冲程。由于滑块在导杆导轨上的滑动，使得曲柄对导杆作用力随悬点载荷大小的变化而自行调整，曲柄轴净扭矩始终处于最佳状态，净扭矩曲线非常平缓，载荷不均匀系数CLF趋近于1，大大降低了电动机的装机功率，电动机输出功率均匀性得到了极大的提高。
党进; 倪风雷; 刘业超; 刘宏
2011-01-01
Considering external disturbance, friction, parameters variation, modeling errors and other issues in flexible joint robot control system, the external disturbance is divided into deterministic part and uncertainty part, and the friction into linear part and nonlinear part, then a new structure robust controller based on the combination of feedforward compensation and fuzzy sliding mode control is proposed. The controller consists of two parts, the part associated with the robot structure itself, deterministic disturbance and the linear part of the friction can be eliminate effectively by computed torque and feedforward compensation. And the fuzzy-sliding mode control of the proposed controller can compensate the external uncertainty disturbance, nonlinear part of friction, parameters variation, modeling error and so on. The experiment results on the platform of HIT four degrees of freedom flexible manipulator show the good position tracking performance and strong anti-interference ability.%针对柔性关节机器人控制系统中存在的扰动力、摩擦力、参数变化以及建模误差等问题,将扰动力分为确定性扰动和不确定性扰动、摩擦力分为线性和非线性部分,并在此基础上提出了一种前馈补偿和模糊滑模相结合的鲁棒控制器.机器人自身结构的相关量、确定性扰动以及摩擦力的线性部分,可以通过控制器的计算力矩和前馈补偿部分进行有效控制,并通过模糊滑模控制器来克服外界的不确定性扰动、摩擦力的非线性部分、参数变化以及建模误差等.在HIT四自由度柔性机械臂上进行了控制器的相关实验,实验结果表明,该控制器具有良好的位置跟踪性能和较强的抗干扰能力.
Bloemer Wilhelm
2010-01-01
Full Text Available Abstract Background Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery. The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68 of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years and the average weight 102.3 kg (75 to 130 kg. The failures of neck adapters were divided into 66% with small CCD of 130° and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. Methods A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Results Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck
Fuzzy Sliding Mode Visual Servo for Robots Based on Epipolar Geometry%基于极线几何的机器人模糊滑模视觉伺服
范昭君; 辛菁
2015-01-01
From the point of view of control, the fuzzy sliding mode controller was designed in order to solve servo problem of ro⁃bot visual based on epipolar geometry. By establishing appropriate fuzzy rule base, buffeting phenomena were effectively weakened or reduced. Simultaneously the robustness and quickness of the system were improved. The effectiveness and feasibility of this approach is tested with the 6⁃DOF robot of visual positioning simulation.%从控制的角度出发，针对基于极线几何的机器人视觉伺服问题，设计了模糊滑模控制器，通过建立合适的模糊规则库，有效地削弱或减小抖振现象，同时提高系统的鲁棒性和快速性。机器人6DOF视觉定位仿真实验表明该方法的有效性和可行性。
许燕青; 毛家松; 刘建峰; 贾锋; 沈胜强
2012-01-01
This paper analyzed its bifurcation and the chaos behavior when the power system is disturbed by a comparatively large periodic load disturbance. Based on the ideological chaos synchronization; the sliding mode controller was designed. In order to realize the chaotic vibration suppression we worked out a stably system; the controller can make the two system synchronization. The deduced method of the controller is given; the Lyapunov theory is used to prove the stability of the system . The simulation results by Matlab show that the controller is effective and can achieve the expected effect.%研究了较大周期性扰动下电力系统的分岔与混沌行为.借鉴混沌同步思想,设计了滑模变结构控制器,将混沌振荡系统同步到稳定的系统,实现混沌振荡抑制.给出了控制器推导方法,采用Lyapunov稳定性理论证明了系统的稳定性.运用Matlab进行数值仿真,结果表明所设计的控制器是有效的,能达到预期效果.
新型静止无功发生器的滑模变结构控制研究%Research on Sliding Mode Variable Structure Control in ASVG
杨华; 戴文进; 王宝福; 林卿生
2009-01-01
In this paper, the principle of advanced static var generator (ASVG) is analyzed. The sliding mode variable structure control (SMVSC) for ASVG is proposed. The controller could improve power angle stability of power system and local voltage characteristics. The simulation results on a single-machine infinite-bus system including ASVG show that the proposed SMVSC can effectively improve stability and dynamic characteristics of power system.%阐述了新型静止无功发生嚣(ASVG)的基本原理,应用滑模变结构理论,设计了能同时改善电力系统功角稳定性,以及装设点的电压动态性能的ASVG的滑模变结构.针对含ASVG的单机无穷大系统进行的电力系统仿真,结果表明,所设计的滑模变结构控制嚣能有效地提高电力系统的稳定性,改善动态响应品质.
Adaptive Q control for Tapping-mode Nano-scanning Using a Piezo-actuated Bimorph Probe
Gunev, Ihsan; Karaman, Sertac; Basdogan, Cagatay
2012-01-01
A new approach, called Adaptive Q-control, for tapping-mode Atomic Force Microscopy (AFM) is introduced and implemented on a home-made AFM set-up utilizing a Laser Doppler Vibrometer (LDV) and a piezo-actuated bimorph probe. In the standard Q-control, the effective Q-factor of the scanning probe is adjusted prior to the scanning depending on the application. However, there is a trade-off in setting the effective Q-factor of an AFM probe. The Q-factor is either increased to reduce the tapping forces or decreased to increase the maximum achievable scan speed. Realizing these two benefits simultaneously using the standard Q-control is not possible. In adaptive Q-control, the Q-factor of the probe is set to an initial value as in standard Q-control, but then modified on the fly during scanning when necessary to achieve this goal. In this paper, we present the basic theory behind the adaptive Q-control, the electronics enabling the on-line modification of the probe's effective Q-factor, and the results of the expe...