Constrained Adaptive-Gain Super-Twisting Sliding Mode Control for Manipulator with Input Saturation

In this paper, a novel adaptive-gain multivariable generalized super-twisting sliding mode control scheme based on an anti-windup compensator is proposed to manipulator system with input saturation and unknown disturbances. Based on the super-twisting sliding mode structure, a modified sliding mode manifold is proposed to avoid the singular phenomenon of terminal sliding mode and improve the convergence speed. To address the problems of unknown disturbances and control gain adjustment in the manipulator system, a modified adaptive-gain law is derived for tuning the control gains of the super-twisting controller, which can attenuate chattering efficiently. To address the problem of input saturation, a novel anti-windup compensator is designed to compensate the closed-loop performance of the manipulator system under saturation. Simulation results show the effectiveness of the proposed control scheme, which can adjust the controller gains to ensure better tracking performance in the event of input saturation.