Robust Adaptive Synchronization of Chaotic Systems With Nonsymmetric Input Saturation Constraints

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Samaneh Mohammadpour ◽  
Tahereh Binazadeh
Keyword(s):  
Chaotic Systems ◽  
Sliding Mode ◽  
Input Saturation ◽  
Adaptive Synchronization ◽  
Adaptive Sliding Mode Controller ◽  
Robust Synchronization ◽  
Effective Performance ◽  
Saturation Constraints ◽  
Robust Adaptive ◽  
Input Saturation Constraints

This paper considers the robust synchronization of chaotic systems in the presence of nonsymmetric input saturation constraints. The synchronization happens between two nonlinear master and slave systems in the face of model uncertainties and external disturbances. A new adaptive sliding mode controller is designed in a way that the robust synchronization occurs. In this regard, a theorem is proposed, and according to the Lyapunov approach the adaptation laws are derived, and it is proved that the synchronization error converges to zero despite of the uncertain terms in master and slave systems and nonsymmetric input saturation constraints. Finally, the proposed method is applied on chaotic gyro systems to show its applicability. Computer simulations verify the theoretical results and also show the effective performance of the proposed controller.

scholarly journals Adaptive Synchronization for Two Different Stochastic Chaotic Systems with Unknown Parameters via a Sliding Mode Controller

2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Zengyun Wang ◽  
Lihong Huang ◽  
Xuxin Yang ◽  
Dingyang Lu
Keyword(s):  
Chaotic Systems ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Adaptive Synchronization ◽  
Sliding Mode Controller ◽  
Unknown Parameters ◽  
Adaptive Sliding Mode ◽  
Adaptive Sliding Mode Controller ◽  
Main Work ◽  
Robust Adaptive

This paper investigates the problem of synchronization for two different stochastic chaotic systems with unknown parameters and uncertain terms. The main work of this paper consists of the following aspects. Firstly, based on the Lyapunov theory in stochastic differential equations and the theory of sliding mode control, we propose a simple sliding surface and discuss the occurrence of the sliding motion. Secondly, we design an adaptive sliding mode controller to realize the asymptotical synchronization in mean squares. Thirdly, we design an adaptive sliding mode controller to realize the almost surely synchronization. Finally, the designed adaptive sliding mode controllers are used to achieve synchronization between two pairs of different stochastic chaos systems (Lorenz-Chen and Chen-Lu) in the presence of the uncertainties and unknown parameters. Numerical simulations are given to demonstrate the robustness and efficiency of the proposed robust adaptive sliding mode controller.

Observer-based synchronization of uncertain chaotic systems subject to input saturation

2017 ◽  
Vol 40 (8) ◽  
pp. 2526-2535 ◽  
Author(s):  
S Mohammadpour ◽  
T Binazadeh
Keyword(s):  
Chaotic Systems ◽  
Actuator Saturation ◽  
Input Saturation ◽  
State Variables ◽  
Adaptive Stabilization ◽  
External Disturbances ◽  
Van Der Pol ◽  
Robust Synchronization ◽  
Effective Performance ◽  
Uncertain Chaotic Systems

This paper considers the synchronization between two chaotic systems (i.e. master and slave systems) in the presence of practical constraints. The considered constraints are: the unavailability of state variables of both master and slave system, the presence of non-symmetric input saturation, model uncertainties and/or external disturbances (matched and/or unmatched). Considering these constraints, an adaptive robust observer-based controller is designed, which guarantees synchronization between the chaotic systems. For this purpose, a theorem is given and, according to a Lyapunov adaptive stabilization approach, it is proved that the robust synchronization via the proposed observer-based controller is guaranteed in the presence of actuator saturation and it is shown that even if the control signal is saturated, the proposed controller leads to a robust synchronization objective. Finally, in order to show the applicability of the proposed controller, it is applied on the Van der Pol chaotic systems. Computer simulations verify the theoretical results and show the effective performance of the proposed controller.

Trajectory tracking control of electric sail with input uncertainty and saturation constraint

2016 ◽  
Vol 39 (7) ◽  
pp. 1007-1016 ◽  
Author(s):  
Yu Wang ◽  
Bingxiu Bian
Keyword(s):  
Solar Wind ◽  
Trajectory Tracking ◽  
Closed Loop ◽  
Sliding Mode ◽  
Input Saturation ◽  
Asymptotically Stable ◽  
Closed Loop System ◽  
Saturation Constraints ◽  
Non Linear System ◽  
Input Saturation Constraints

The electric sail (ES) is a novel propellantless propulsion concept, which extracts the solar wind momentum by repelling the positively charged ions. Due to the difficulty of attitude adjustment by the large flexible structure and the uncertainty of ion density, velocity and electron temperature by solar wind, there exist thrust input uncertainty and saturation with time-varying bounds for ES. The trajectory tracking problem for ES in three-dimensional (3-D) space is studied, and the composite sliding mode control scheme with corresponding guidance strategy is proposed for the single-input–multiple-output (SIMO) non-linear system. The hierarchical sliding surfaces are constructed with an auxiliary design system to analyse the effect of input saturation constraints and decouple the SIMO non-linear system to reduce the control complexity. Also, the disturbance estimation based on a super-twisting algorithm is employed to decrease the switch chattering and improve the system robustness. It is proved that all the sliding mode surfaces are asymptotically stable, and all the signals of the closed-loop system are bounded with input saturation constraints. Furthermore, all the signals are converging to zero and the closed-loop system is asymptotically stable without saturation. Finally, the simulation demonstrates the proposed composite sliding mode control is fit for ES 3-D trajectory tracking.

ADAPTIVE SYNCHRONIZATION OF CHAOTIC SYSTEMS VIA STATE OR OUTPUT FEEDBACK CONTROL

2001 ◽  
Vol 11 (04) ◽  
pp. 1149-1158 ◽  
Author(s):  
YIGUANG HONG ◽  
HUASHU QIN ◽  
GUNARONG CHEN
Keyword(s):  
Output Feedback ◽  
Chaotic Systems ◽  
Sliding Mode ◽  
Output Feedback Control ◽  
Robust Adaptive Control ◽  
Adaptive Synchronization ◽  
Feedback Controls ◽  
Adaptive Controllers ◽  
Modification Technique ◽  
Robust Adaptive

This letter addresses the problem of robust adaptive control for synchronization of continuous-time coupled chaotic systems, which may be subjected to disturbances. A general model is studied via two different approaches, using either state feedback or measured output feedback controls. Adaptive controllers are designed, in which a sliding mode structure is employed to increase the robustness of the closed-loop systems. When only output variables are measurable for synchronization, the adaptive controllers are designed by incorporating with a filter and using the so-called σ-modification technique. Several numerical examples are presented to show the effectiveness of the proposed chaos synchronization methods.

Adaptive Modified Hybrid Robust Projective Synchronization Between Identical and Nonidentical Fractional-Order Complex Chaotic Systems With Fully Unknown Parameters

2016 ◽  
Vol 11 (4) ◽  
Author(s):  
Hadi Delavari ◽  
Milad Mohadeszadeh
Keyword(s):  
Fractional Order ◽  
Chaotic Systems ◽  
Sliding Mode ◽  
Adaptive Controller ◽  
Projective Synchronization ◽  
Order Complex ◽  
Unknown Parameters ◽  
Adaptive Sliding Mode Controller ◽  
Robust Adaptive ◽  
Complex Chaotic Systems

In this paper, a robust adaptive sliding mode controller is proposed. Under the existence of external disturbances, modified hybrid projective synchronization (MHPS) between two identical and two nonidentical fractional-order complex chaotic systems is achieved. It is shown that the response system could be synchronized with the drive system up to a nondiagonal scaling matrix. An adaptive controller and parameter update laws are investigated based on the Lyapunov stability theorem. The closed-loop stability conditions are derived based on the fractional-order Lyapunov function and Mittag-Leffler function. Finally, numerical simulations are given to verify the theoretical analysis.

Mechanical design and robust tracking control of a class of antagonistic variable stiffness actuators based on the equivalent nonlinear torsion springs

2018 ◽  
Vol 232 (10) ◽  
pp. 1337-1355 ◽  
Author(s):  
Jishu Guo ◽  
Guohui Tian
Keyword(s):  
Tracking Control ◽  
Control Method ◽  
Sliding Mode ◽  
Input Saturation ◽  
Variable Stiffness ◽  
Robust Tracking ◽  
Torsion Spring ◽  
Saturation Constraints ◽  
Variable Stiffness Actuator ◽  
Input Saturation Constraints

The novel conceptual model of the antagonistic variable stiffness actuator based on the equivalent nonlinear torsion spring and the friction damper is demonstrated. For the dynamic model of the antagonistic variable stiffness actuator in the presence of parametric uncertainties, unknown bounded friction torques, unknown bounded external disturbance, and input saturation constraints, using the coordinate transformation, the state space model of the antagonistic variable stiffness actuator with composite disturbances and input saturation constraints is transformed into an extended integral chain–type pseudo-linear system with input saturation constraints. Subsequently, a combination of the linear extended state observer, sliding mode control, and adaptive input saturation compensation law is adopted for the design of the robust tracking controller that simultaneously regulates the position and stiffness of the antagonistic equivalent nonlinear torsion spring-based variable stiffness actuator. Under the proposed controller, the semi-global uniformly ultimately bounded stability of the closed-loop system has been proved via Lyapunov stability analysis. Simulation studies demonstrate the effectiveness and the robustness of the proposed robust adaptive tracking control method for the antagonistic variable stiffness actuator.

scholarly journals Synchronization for a Class of Uncertain Fractional Order Chaotic Systems with Unknown Parameters Using a Robust Adaptive Sliding Mode Controller

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yan Yan
Keyword(s):  
Fractional Order ◽  
Chaos Synchronization ◽  
Chaotic Systems ◽  
Sliding Mode ◽  
External Disturbance ◽  
Lyapunov Stability Theory ◽  
Unknown Parameters ◽  
Adaptive Sliding Mode Controller ◽  
Mode Synchronization ◽  
Robust Adaptive

This paper deals with the synchronization of a class of fractional order chaotic systems with unknown parameters and external disturbance. Based on the Lyapunov stability theory, a fractional order sliding mode is constructed and a controller is proposed to realize chaos synchronization. The presented method not only realizes the synchronization of the considered chaotic systems but also enhances the robustness of sliding mode synchronization. Finally, some simulation results demonstrate the effectiveness and robustness of the proposed method.

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