Research on adaptive non-singular fast terminal sliding mode control based on variable exponential power reaching law in manipulators

2021 ◽  
pp. 095965182110402
Author(s):  
Xin Zhang ◽  
Ran Shi
Keyword(s):  
Control System ◽  
Upper Bound ◽  
Sliding Mode ◽  
Convergence Speed ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Slow Convergence ◽  
Reaching Law ◽  
Fast Terminal Sliding Mode ◽  
Exponential Power

Aiming at the manipulator control system is susceptible to model parameter uncertainty and external disturbance. In this article, an adaptive non-singular fast terminal sliding mode control based on variable exponential power reaching law is proposed. First, due to the slow convergence speed and large chattering of the traditional reaching law, the variable exponential power reaching law is designed in this article. It can adaptively change the reached speed according to the system state, improve the accuracy of the control system and reduce chattering. Second, compared to the slow convergence speed of traditional sliding mode surfaces, this article uses non-singular fast terminal sliding mode surfaces to speed up the system error convergence speed. At the same time, in view of the problem that the disturbance has an uncertain upper bound in the actual problem, the adaptive law is used to estimate the uncertain upper bound of the system disturbance. And by introducing a time-varying boundary layer to improve the symbolic function in the control law. Finally, the Lyapunov function is used to prove the stability of the control system. The simulation results show that the controller designed in this article has good position tracking performance and strong anti-disturbance ability.

scholarly journals Adaptive Fractional-Order Nonsingular Fast Terminal Sliding Mode Control for Manipulators

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xin Zhang ◽  
Ran Shi
Keyword(s):  
Control System ◽  
Fractional Order ◽  
Sliding Mode ◽  
External Disturbance ◽  
Convergence Speed ◽  
System State ◽  
Terminal Sliding Mode ◽  
Reaching Law ◽  
Fast Terminal Sliding Mode ◽  
Manipulator Control

When the manipulator system is subject to unknown disturbance, in order to improve the tracking accuracy of the manipulator, this paper designs a fractional-order nonsingular fast terminal sliding mode (FONFTSM) controller. The controller is divided into three parts. First of all, in order to improve the performance of the sliding stage, this paper designs a FONFTSM surface. By introducing a fractional-order operator, the convergence speed and accuracy of the system state are effectively improved. Secondly, in view of the problems of large chattering and slow convergence speed in the reaching stage, this paper designs a variable exponential power-reaching law (VEPRL), which has the ability to change the exponential coefficients according to the system state adaptively. At the same time, an adaptive law is designed to adjust the coefficients of the reaching law adaptively, which enhances the robustness of the control system. Finally, a disturbance observer is used to estimate the unknown external disturbance in real time so as to perform feedforward compensation for the control system, which effectively improves the accuracy of the manipulator control system. The stability of the manipulator control system is proved by the Lyapunov function. Simultaneously, the controller designed in this paper is compared with different controllers, which proves that the controller designed in this paper has strong robustness, high control accuracy, and fast convergence speed.

scholarly journals A New Variable Exponential Power Reaching Law of Complementary Terminal Sliding Mode Control

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Feng Xu ◽  
Na An ◽  
Jianlin Mao ◽  
Shubo Yang
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Terminal Sliding Mode Control ◽  
Sliding Surface ◽  
Terminal Sliding Mode ◽  
Reaching Law ◽  
Mode Control ◽  
Exponential Power

In this article, a new nonlinear algorithm based on the sliding mode control is developed for the ball and plate control system to improve dynamic response and steady-state tracking accuracy of the control system. First, a new sliding mode reaching law is proposed, variable exponential power reaching law (VEPRL), which is expressed in two different forms including a nonlinear combination function term and a variable exponential power term, so that it can be adjusted adaptively according to the state of the system by the variable exponential power reaching term during the reaching process. The computation results show that it can not only effectively weaken the chattering phenomenon but also increase the rate of the system state reaching to the sliding mode surface. Moreover, it has the characteristic of global finite-time convergence. Besides, a complementary terminal sliding mode control (CTSMC) method is designed by combining the integral terminal sliding surface with the complementary sliding surface to improve the convergence rate. Based on the proposed VEPRL and CTSMC, a new sliding mode control method for the ball and plate system is presented. Finally, simulation results show the superiority and effectiveness of the proposed control method.

scholarly journals Adaptive Control of MEMS Gyroscope Based on Global Terminal Sliding Mode Controller

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Weifeng Yan ◽  
Juntao Fei
Keyword(s):  
Sliding Mode Control ◽  
Upper Bound ◽  
Sliding Mode ◽  
Tracking Error ◽  
Sliding Mode Controller ◽  
Terminal Sliding Mode Control ◽  
Sliding Surface ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Fast Terminal Sliding Mode

An adaptive global fast terminal sliding mode control (GFTSM) is proposed for tracking control of Micro-Electro-Mechanical Systems (MEMS) vibratory gyroscopes under unknown model uncertainties and external disturbances. To improve the convergence rate of reaching the sliding surface, a global fast terminal sliding surface is employed which can integrate the advantages of traditional sliding mode control and terminal sliding mode control. It can be guaranteed that sliding surface and equilibrium point can be reached in a shorter finite time from any initial state. In the presence of unknown upper bound of system nonlinearities, an adaptive global fast terminal sliding mode controller is derived to estimate this unknown upper bound. Simulation results demonstrate that the tracking error can be attenuated efficiently and robustness of the control system can be improved with the proposed adaptive global fast terminal sliding mode control.

Fast Terminal Sliding-Mode Control with an Integral Filter Applied to a Longitudinal Axis of Flying Vehicles

2019 ◽  
Vol 16 (8) ◽  
pp. 3141-3153 ◽  
Author(s):  
Elham Ramezani ◽  
Seyyed Mohammad Hosseini Rostami
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
Flight Control ◽  
Sliding Mode ◽  
Variable Structure ◽  
Sliding Mode Controller ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Fast Terminal Sliding Mode

The automatic pilot flight control system is undoubtedly one of the most important parts of the flying vehicle that provide stability and to operate appropriately in the guidance section. Considering to nonlinear, dynamic and time-varying system, structural and parametric uncertainties of the flying vehicles, in flight control, varietal control approach have to achieve stability, proper operation as well as decreasing effect of uncertainties and modeling errors. In this paper, designing of the longitudinal flying vehicles autopilot a Fast Terminal Sliding Mode Control (FTSMC). Variable structure systems because of the robustness effect on uncertainty and the effects on disturbances which a contributor to widespread efficiency. One of the methods for controlling the variable structure is a sliding mode, which is one of the nonlinear controllers that can control the system in the structured uncertainties and unstructured uncertainties. Additionally, in the method of classic sliding Mode Control is got convergence of states equilibrium point by an asymptotic curve. While proportional Integral Sliding Mode Control has the convergence of states to the equilibrium point in finite time. One of the issues is that finite time cannot determine the time of convergence when the state turn initial position to a final position. The proposed method is based on the Lyapunov stability theory and has guaranteed stability of the control system. The controller is robust to external disturbances and unmodified dynamics. Three types of controllers which are multi-input-multi-output (MIMO) system with random uncertainty are designed. Furthermore, the classic sliding mode controller, the proportional-integral sliding mode controller as well as the integral terminal sliding mode controller are reviewed. A glance at the results simulates shows an improved in the proposed method. Simulations are done using MATLAB software.

A nonsingular fast terminal sliding mode control with an exponential reaching law for robot manipulators

2018 ◽  
Vol 233 (5) ◽  
pp. 1575-1587 ◽  
Author(s):  
Liyin Zhang ◽  
Yuxin Su ◽  
Haihong Wang
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Robot Manipulators ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Reaching Law ◽  
Mode Control ◽  
Fast Terminal Sliding Mode ◽  
Exponential Reaching Law

This paper presents an improved robust tracking control for uncertain robot manipulators. An approximate fast terminal sliding mode control is proposed by integrating a nonsingular fast terminal sliding surface with an exponential reaching law. Lyapunov stability theory is employed to prove the global approximate finite-time stability ensuring that the tracking errors converge to an arbitrary small ball centered at zero within a finite time and thereafter arrive at zero asymptotically. The benefits of this integrated design are that it can ensure faster transient and higher steady-state tracking precision with lower chattering. Simulations and experiments are presented to demonstrate the effectiveness and improved performances of the proposed approach.

Adaptive nonsingular proportional–integral–derivative-type terminal sliding mode tracker based on rapid reaching law for nonlinear systems

2020 ◽  
pp. 107754632096428
Author(s):  
Ankur Goel ◽  
Saleh Mobayen
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Terminal Sliding Mode Control ◽  
Proportional Integral Derivative ◽  
Terminal Sliding Mode ◽  
Reaching Law ◽  
Proportional Integral ◽  
Mode Control ◽  
Fast Terminal Sliding Mode ◽  
Derivative Type

This article deals with a novel adaptive robust controller for uncertain nonlinear systems relying on a proportional–integral–derivative-type nonsingular fast terminal sliding mode control. In this nonsingular proportional–integral–derivative-type terminal sliding mode controller nonsingular fast terminal sliding mode control, the nonsingular fast terminal sliding mode control sliding surface is modified with integral to match with the proportional–integral–derivative-type structure to obtain the essential attributes, namely, quick transient response, finite-time convergence, negligible steady-state error, and chattering cancellation. Furthermore, a novel rapid reaching law is also suggested with dynamic proof for providing the robustness during transient phase. The controller stability and convergence is mathematically analyzed using the Lyapunov theory. The overall control structure is simulated on MATLAB® software and tested for trajectory tracking of a two-degree-of-freedom revolute–prismatic joint industrial robotic manipulator. The rigorous test results show the performance efficacy of the innovative controller.

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