Practical Tracking Control of Robot Manipulators With Continuous Fractional-Order Nonsingular Terminal Sliding Mode

2016 ◽  
Vol 63 (10) ◽  
pp. 6194-6204 ◽  
Author(s):  
Yaoyao Wang ◽  
Linyi Gu ◽  
Yihong Xu ◽  
Xiaoxu Cao
Keyword(s):  
Fractional Order ◽  
Tracking Control ◽  
Sliding Mode ◽  
Robot Manipulators ◽  
Terminal Sliding Mode ◽  
Nonsingular Terminal Sliding Mode

Practical continuous fractional-order nonsingular terminal sliding mode control of underwater hydraulic manipulators with valve deadband compensators

2018 ◽  
Vol 232 (4) ◽  
pp. 459-469 ◽  
Author(s):  
Yaoyao Wang ◽  
Bai Chen ◽  
Hongtao Wu
Keyword(s):  
Fractional Order ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Terminal Sliding Mode Control ◽  
Control Performance ◽  
Terminal Sliding Mode ◽  
Hydraulic Manipulators ◽  
Nonsingular Terminal Sliding Mode

For the multi-degrees of freedom control problem of underwater hydraulic manipulators with non-ignorable valve deadband and strong lumped nonlinearities and uncertainties, a practical continuous fractional-order nonsingular terminal sliding mode control design together with a deadband compensator is presented and studied. The presented method contains three parts a time delay estimation utilized to nearly estimate and compensate the extremely complicated system dynamics, a continuous fractional-order nonsingular terminal sliding mode used to ensure high control performance against the strong lumped nonlinearities and uncertainties, and a valve deadband compensator used to compensate for the non-ignorable valve deadband. The proposed method is model-free thanks to the time delay estimation, and can ensure satisfactory control performance thanks to the continuous fractional-order nonsingular terminal sliding mode and deadband compensator. Stability of the closed-loop control system including the deadband compensator is proved rigorously. Finally, practical 2-degrees of freedom experiments are performed, and corresponding results effectively demonstrate the superiorities of the newly presented controller with deadband compensator.

Fractional-order nonsingular terminal sliding mode control via a disturbance observer for a class of nonlinear systems with mismatched disturbances

2020 ◽  
pp. 107754632092526
Author(s):  
Amir Razzaghian ◽  
Reihaneh Kardehi Moghaddam ◽  
Naser Pariz
Keyword(s):  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Finite Time ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Sliding Mode Controller ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Nonsingular Terminal Sliding Mode

This study investigates a novel fractional-order nonsingular terminal sliding mode controller via a finite-time disturbance observer for a class of mismatched uncertain nonlinear systems. For this purpose, a finite-time disturbance observer–based fractional-order nonsingular terminal sliding surface is proposed, and the corresponding control law is designed using the Lyapunov stability theory to satisfy the sliding condition in finite time. The proposed fractional-order nonsingular terminal sliding mode control based on a finite-time disturbance observer exhibits better control performance; guarantees finite-time convergence, robust stability of the closed-loop system, and mismatched disturbance rejection; and alleviates the chattering problem. Finally, the effectiveness of the proposed fractional-order robust controller is illustrated via simulation results of both the numerical and application examples which are compared with the fractional-order nonsingular terminal sliding mode controller, sliding mode controller based on a disturbance observer, and integral sliding mode controller methods.

Distributed Finite-Time Coordinated Attitude Tracking Control for Multiple Spacecraft with Actuator Saturation

2020 ◽  
Vol 29 (13) ◽  
pp. 2050212
Author(s):  
Zhi Gao ◽  
Zhihao Zhu ◽  
Yu Guo
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Actuator Saturation ◽  
Sliding Mode ◽  
Terminal Sliding Mode ◽  
Mode Function ◽  
Nonsingular Terminal Sliding Mode ◽  
Attitude Tracking ◽  
Multiple Spacecraft ◽  
Attitude Tracking Control

For multi-spacecraft with actuator saturation, inertia uncertainties and external disturbances, a distributed finite-time coordinated attitude tracking control problem for the spacecraft with the communication topology containing fewer information paths is investigated. Aiming at reducing the communication path, a class of distributed finite-time state observers is designed. To speed up the convergence rate of the multiple spacecraft system, a fast nonsingular terminal sliding mode function is proposed. Moreover, an adaptive control term is proposed to suppress the impact of the external state-dependent disturbances and unknown time-varying inertia uncertainties. Further considering the actuator saturation owing to its physical limitations, a saturation function is designed. With the distributed finite-time observers, the fast nonsingular terminal sliding mode function, the adaptive update law and the saturation function, a distributed finite-time coordinated attitude tracking saturation controller is designed. Using the proposed controller, the follower can synchronize with the common leader with time-varying trajectory in finite time. Simulation results demonstrate the effectiveness of the designed controller.

Finite-time attitude tracking control of air bearing table for spacecraft rendezvous and docking

2016 ◽  
Vol 232 (1) ◽  
pp. 96-110 ◽  
Author(s):  
Cheng Huang ◽  
Yan Wang ◽  
Xing-lin Chen
Keyword(s):  
Finite Time ◽  
Tracking Control ◽  
Sliding Mode ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Finite Time Stability ◽  
Nonsingular Terminal Sliding Mode ◽  
Attitude Tracking ◽  
Attitude Tracking Control ◽  
Rendezvous And Docking

This paper studies the problem of attitude tracking control for spacecraft rendezvous and docking based on a physical ground simulation system. Two finite-time controllers based on quaternion are proposed by using a novel fast nonsingular terminal sliding mode surface associated with the adaptive control, the novel fast nonsingular terminal sliding mode surface not only contains the advantages of the fast nonsingular terminal sliding mode surface, but also can eliminate unwinding caused by the quaternion. The first controller, which is continuous and chattering-free, can compensate unknown constant external disturbances, while the second controller can both compensate parametric uncertainties and varying external disturbances with unknown bounds without chattering. Lyapunov theoretical analysis and simulation results show that the two controllers can make the closed-loop system errors converge to zero in finite time and guarantee the finite-time stability of the system.

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