A Fast Terminal Sliding Mode Control Strategy for Trajectory Tracking Control of Robotic Manipulators

Abstract

This paper proposes a fast terminal sliding mode control strategy for trajectory tracking control of robotic manipulators. Firstly, to degrade the chattering behavior and speed up the fast response of the conventional Terminal Sliding Mode Control, a novel robust, reaching control law with two variable power components is introduced. With this proposal, the state error variables of the system quickly converge on the sliding surface whether their initial value is far or near to the sliding surface. Secondly, a Fast Terminal Sliding Mode surface is designed to guarantee that the system states arrive at the equilibrium and stabilize along the sliding surface with rapid convergence speed. The result is a new control strategy is formed based on the suggested reaching control law and the above sliding surface. Thanks to this hybrid method, the control performance expectations are guaranteed such as faster convergence, robustness with exterior disturbance and dynamic uncertainties, high tracking accuracy, and finite-time convergence. Moreover, the asymptotic stability and finite-time convergence of the control system are fully confirmed by Lyapunov theory. Finally, computer simulation examples are performed to verify the effectiveness of the suggested control strategy.