Adaptive Non-singular Terminal Sliding Mode Fault-tolerant Control of Robotic Manipulators Based on Contour Error Compensation

TL;DR

This paper presents an adaptive non-singular terminal sliding mode control method with contour error compensation for robotic manipulators, effectively handling uncertainties and actuator faults to improve contour tracking accuracy.

Contribution

It introduces a singularity-free, adaptive control strategy with cross-coupling and contour compensation, advancing robust fault-tolerant control for robotic manipulators.

Findings

Effective contour tracking demonstrated through simulations.

Robustness against dynamic uncertainties and actuator faults.

Finite-time stability of the control strategy proven.

Abstract

To achieve accurate contour tracking of robotic manipulators with dynamic uncertainties, coupling and actuator faults, an adaptive non-singular terminal sliding mode control (ANTSMC) based on cross-coupling is proposed. Firstly, the singularity is eliminated completely by using a terminal sliding mode manifold. Secondly, an adaptive tuning approach is selected for avoid the demand of the bound of system uncertainty, and the stability of the proposed control strategy is demonstrated by the sense of the finite-time stability theory. Furthermore, the cross-coupled ANTSMC law is proposed for contour tracking at the end-effectors level of robotic manipulators. Thirdly, a unified framework of cross-coupling contour compensation and reference position pre-compensation is designed by combining cross-coupling control with parabolic transition trajectory planning. Finally, numerical simulation and experimental results are shown to prove the effectiveness of the proposed control strategy.