Nonlinear Disturbance Observer Based Sliding Mode Tracking Control for Robotic Manipulators

Abstract

Aiming at the problem of low trajectory tracking control accuracy caused by internal uncertainties and external disturbances in the control process of robotic manipulators, a sliding mode control method of robotic manipulators based on nonlinear disturbance observer is proposed. Firstly, a nonlinear disturbance observer is designed to estimate the internal uncertainties and external disturbances of the system. In order to avoid the measurement of acceleration feedback term, an auxiliary function is properly introduced. Secondly, in order to reduce the chattering effect of the system, the control input of the system is compensated in real time. At the same time, in order to improve the convergence rate and tracking accuracy of the system, the sliding mode controller is designed with an improved reaching law. Finally, the simulation is performed and the comparison results show that the proposed control strategy is more convincing.