ADAPTIVE SYNCHRONOUS SLIDING MODE CONTROLLER FOR ROBOT MANIPULATORS

Abstract

Improving the quality of trajectory tracking for robot manipulators is always an attractive topic in the research community. This is a challenging problem because robot manipulators are complex nonlinear systems and are often subject to fluctuations in loads and external disturbances. This paper proposes an adaptive synchronous sliding control scheme to improve trajectory tracking performance for robot manipulators. Firstly, the synchronous tracking errors, cross synchronization errors, and sliding surfaces are defined, and the synchronization tracking error dynamics are constructed. Secondly, a control law is proposed, in which the unknown component of the model is approximated online by a neural network, and the parameters of the switching component are determined by fuzzy logic based on the values of synchronous tracking errors. The proposed controller ensures synchronous tracking and approximation errors are UUB (Ultimately Uniformly Bounded). Finally, the performance of the proposed algorithm is verified by comparative simulation on Matlab-Simulink. The simulation results show the effectiveness of the proposed controller with small synchronous tracking errors about , fast convergence about 1s, and significantly reduced chattering phenomenon.