A New Finite Time Control Solution for Robotic Manipulators Based on Nonsingular Fast Terminal Sliding Variables and the Adaptive Super-Twisting Scheme

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Vo Anh Tuan ◽  
Hee-Jun Kang
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Robotic Manipulators ◽  
Control Law ◽  
Continuous Control ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Position Errors ◽  
Time Control

In this study, a new finite time control method is suggested for robotic manipulators based on nonsingular fast terminal sliding variables and the adaptive super-twisting method. First, to avoid the singularity drawback and achieve the finite time convergence of positional errors with a fast transient response rate, nonsingular fast terminal sliding variables are constructed in the position errors' state space. Next, adaptive tuning laws based on the super-twisting scheme are presented for the switching control law of terminal sliding mode control (TSMC) so that a continuous control law is extended to reject the effects of chattering behavior. Finally, a new finite time control method ensures that sliding motion will take place, regardless of the effects of the perturbations and uncertainties on the robot system. Accordingly, the stabilization and robustness of the suggested control system can be guaranteed with high-precision performance. The robustness issue and the finite time convergence of the suggested system are totally confirmed by the Lyapunov stability principle. In simulation studies, the experimental results exhibit the effectiveness and viability of our proposed scheme for joint position tracking control of a 3DOF PUMA560 robot.

A novel robust finite-time tracking control of uncertain robotic manipulators with disturbances

2020 ◽  
pp. 107754632098244
Author(s):  
Hamid Razmjooei ◽  
Mohammad Hossein Shafiei ◽  
Elahe Abdi ◽  
Chenguang Yang
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Robotic Manipulators ◽  
Sliding Mode Controller ◽  
Time Varying ◽  
State Variables ◽  
Terminal Sliding Mode ◽  
Control Laws ◽  
Finite Time Boundedness

In this article, an innovative technique to design a robust finite-time state feedback controller for a class of uncertain robotic manipulators is proposed. This controller aims to converge the state variables of the system to a small bound around the origin in a finite time. The main innovation of this article is transforming the model of an uncertain robotic manipulator into a new time-varying form to achieve the finite-time boundedness criteria using asymptotic stability methods. First, based on prior knowledge about the upper bound of uncertainties and disturbances, an innovative finite-time sliding mode controller is designed. Then, the innovative finite-time sliding mode controller is developed for finite-time tracking of time-varying reference signals by the outputs of the system. Finally, the efficiency of the proposed control laws is illustrated for serial robotic manipulators with any number of links through numerical simulations, and it is compared with the nonsingular terminal sliding mode control method as one of the most powerful finite-time techniques.

Continuous finite-time control for robotic manipulators with terminal sliding mode

Automatica ◽  
2005 ◽  
Vol 41 (11) ◽  
pp. 1957-1964 ◽  
Author(s):  
Shuanghe Yu ◽  
Xinghuo Yu ◽  
Bijan Shirinzadeh ◽  
Zhihong Man
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Robotic Manipulators ◽  
Terminal Sliding Mode ◽  
Time Control

Immersion and invariance adaptive finite-time control of air-breathing hypersonic vehicles

2018 ◽  
Vol 233 (7) ◽  
pp. 2626-2641 ◽  
Author(s):  
Chao Han ◽  
Zhen Liu ◽  
Jianqiang Yi
Keyword(s):  
Control System ◽  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Second Order ◽  
Hypersonic Vehicles ◽  
Terminal Sliding Mode ◽  
Air Breathing ◽  
Immersion And Invariance ◽  
Time Control

In this paper, a novel adaptive finite-time control of air-breathing hypersonic vehicles is proposed. Based on the immersion and invariance theory, an adaptive finite-time control method for general second-order systems is first derived, using nonsingular terminal sliding mode scheme. Then the method is applied to the control system design of a flexible air-breathing vehicle model, whose dynamics can be decoupled into first-order and second-order subsystems by time-scale separation principle. The main features of this hypersonic vehicle control system lie in the design flexibility of the parameter adaptive laws and the rapid convergence to the equilibrium point. Finally, simulations are conducted, which demonstrate that the control system has the features of fast and accurate tracking to command trajectories and strong robustness to parametric and non-parametric uncertainties.

scholarly journals RBFNN-Based Singularity-Free Terminal Sliding Mode Control for Uncertain Quadrotor UAVs

2021 ◽  
Vol 2021 ◽  
pp. 1-10 ◽  
Author(s):  
Meiling Tao ◽  
Xiongxiong He ◽  
Shuzong Xie ◽  
Qiang Chen
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Auxiliary Function ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Time Control ◽  
Control Scheme ◽  
Unknown Disturbances ◽  
Quadrotor Unmanned Aerial Vehicles

In this article, a singularity-free terminal sliding mode (SFTSM) control scheme based on the radial basis function neural network (RBFNN) is proposed for the quadrotor unmanned aerial vehicles (QUAVs) under the presence of inertia uncertainties and external disturbances. Firstly, a singularity-free terminal sliding mode surface (SFTSMS) is constructed to achieve the finite-time convergence without any piecewise continuous function. Then, the adaptive finite-time control is designed with an auxiliary function to avoid the singularity in the error-related inverse matrix. Moreover, the RBFNN and extended state observer (ESO) are introduced to estimate the unknown disturbances, respectively, such that prior knowledge on system model uncertainties is not required for designing attitude controllers. Finally, the attitude and angular velocity errors are finite-time uniformly ultimately bounded (FTUUB), and numerical simulations illustrated the satisfactory performance of the designed control scheme.

scholarly journals An Active Fault-Tolerant Control for Robotic Manipulators Using Adaptive Non-Singular Fast Terminal Sliding Mode Control and Disturbance Observer

Actuators ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 332
Author(s):  
Van-Cuong Nguyen ◽  
Phu-Nguyen Le ◽  
Hee-Jun Kang
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Disturbance Observer ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Robotic Manipulators ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Fast Terminal Sliding Mode

In this study, a fault-tolerant control (FTC) tactic using a sliding mode controller–observer method for uncertain and faulty robotic manipulators is proposed. First, a finite-time disturbance observer (DO) is proposed based on the sliding mode observer to approximate the lumped uncertainties and faults (LUaF). The observer offers high precision, quick convergence, low chattering, and finite-time convergence estimating information. Then, the estimated signal is employed to construct an adaptive non-singular fast terminal sliding mode control law, in which an adaptive law is employed to approximate the switching gain. This estimation helps the controller automatically adapt to the LUaF. Consequently, the combination of the proposed controller–observer approach delivers better qualities such as increased position tracking accuracy, reducing chattering effect, providing finite-time convergence, and robustness against the effect of the LUaF. The Lyapunov theory is employed to illustrate the robotic system’s stability and finite-time convergence. Finally, simulations using a 2-DOF serial robotic manipulator verify the efficacy of the proposed method.

scholarly journals A continuous integral terminal sliding mode control approach for a class of uncertain nonlinear systems

2019 ◽  
Vol 52 (5-6) ◽  
pp. 720-728
Author(s):  
Huawei Niu ◽  
Qixun Lan ◽  
Yamei Liu ◽  
Huafeng Xu
Keyword(s):  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Control Law ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Control Approach ◽  
Mode Control ◽  
Time Control

In this article, the continuous integral terminal sliding mode control problem for a class of uncertain nonlinear systems is investigated. First of all, based on homogeneous system theory, a global finite-time control law with simple structure is proposed for a chain of integrators. Then, inspired by the proposed finite-time control law, a novel integral terminal sliding mode surface is designed, based on which an integral terminal sliding mode control law is constructed for a class of higher order nonlinear systems subject disturbances. Furthermore, a finite-time disturbance observer-based integral terminal sliding mode control law is proposed, and strict theoretical analysis shows that the composite integral terminal sliding mode control approach can eliminate chattering completely without losing disturbance attenuation ability and performance robustness of integral terminal sliding mode control. Simulation examples are given to illustrate the simplicity of the new design approach and effectiveness.

scholarly journals Adaptive chattering-free terminal sliding-mode control for full-order nonlinear system with unknown disturbances and model uncertainties

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142092529
Author(s):  
Lei Wan ◽  
Guofang Chen ◽  
Mingwei Sheng ◽  
Yinghao Zhang ◽  
Ziyang Zhang
Keyword(s):  
Nonlinear Systems ◽  
Sliding Mode Control ◽  
Upper Bound ◽  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Control Law ◽  
Sliding Mode Controller ◽  
Terminal Sliding Mode ◽  
Chattering Free

This study investigates an adaptive chattering-free sliding-mode control method for n-order nonlinear systems with unknown external disturbances and uncertain models. The proposed method takes the advantage of finite-time fast convergence to avoid singularity problem and ensure its robustness against system uncertainty and unknown disturbance. To achieve fast convergence from any initial condition to system origin, a full-order terminal sliding-mode controller containing differential terms is proposed based on the property of n-order nonlinear systems. Then the continuous and smooth actual control law is obtained by integrating the differential control law containing the discontinuous sign function to realize chattering free. Meanwhile, instead of evaluating the fixed upper bound of system uncertainty and interference in practical implementations, an adaptive method is utilized for its unknown upper bound estimation. The convergence of the adaptive terminal sliding-mode controller in finite time is verified based on Lyapunov stability theory. Finally, two simulation results demonstrate the effectiveness of the proposed control method.

Attitude Maneuver Control of Flexible Spacecraft with Finite-Time Convergence

2012 ◽  
Vol 157-158 ◽  
pp. 847-851
Author(s):  
Shu Nan Wu ◽  
Zhao Wei Sun ◽  
Xian De Wu
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Flexible Spacecraft ◽  
Terminal Sliding Mode Control ◽  
Singularity Problem ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Time Control ◽  
Attitude Maneuver ◽  
Sliding Mode Controllers

The attitude maneuver control of flexible spacecraft with finite-time convergence is investigated in this paper. Two terminal sliding mode controllers are proposed to achieve the finite-time control, which guarantee the convergence of attitude maneuver errors in finite time. The singularity problem associated with the terminal sliding mode control is solved by employing a new sliding variable. Numerical simulations are finally provided to illustrate the performance of the proposed controllers.

Robust active finite-time control of gas compressor system surge in the presence of unmatched disturbance and uncertainty

2021 ◽  
pp. 095965182110574
Author(s):  
Jianhua Sun ◽  
Hai Gu ◽  
Jie Zhang ◽  
Hashem Imani Marrani
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Characteristic Curve ◽  
Parametric Uncertainty ◽  
Terminal Sliding Mode ◽  
Finite Time Stability ◽  
Time Control ◽  
Unmatched Uncertainties ◽  
Fuzzy Approximator

Active and robust control of surge instability is a special necessity for optimal and safe operation of centrifugal compressors, and for the purpose, this article presents a new hybrid scheme based on fuzzy and terminal sliding mode methods. The Greitzer model is used to design a novel controller when the disturbance instability in the flow and pressure alike the uncertainity in the compressor characteristic curve and throttle valve are embedded in it. The fuzzy approximator is used to estimate the effects of parametric uncertainty and the nonlinear terms, and the robustness of the proposed method is guaranteed using the terminal sliding mode control method. The Lyapunov criterion is utilized to verify the finite-time stability of the closed-loop system. The performance of the presented method is compared with other methods in the literature through simulations in MATLAB software. The results suggest that our designed controller outperforms the existing ones in terms of surge prevention and robustness against unmatched uncertainties and disturbances.

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