Delta Robot Trajectory Tracking Based on Fuzzy Adaptive Sliding Mode Controller

Abstract

A trajectory tracking controller for Delta robot is developed in this paper. The tracking performance of Delta robot is usually affected by unknown external disturbances, model inaccuracy and uncertain couplings, these are considered as lumped disturbances to the system. Sliding mode control has a good nature of being insensitive to disturbance, however it brings the issue of high-frequency chattering, which is harmful to practical system. In order to alleviate chattering as well as maintain robustness for trajectory tracking of Delta robot, a novel control method combined sliding mode and fuzzy adaptive function is proposed. First, a sliding mode control law is designed. Then, a set of fuzzy logic rules and an adaptive law are introduced, the smooth and continuous output K of the fuzzy function is used to replace the discontinuous product of sign function and a gain vector in sliding mode control law. Moreover, the Lyapunov stability theory is used to prove the finite-time stability of the closed-loop control system. Finally, the numerical simulation results verify the effectiveness and robustness of the proposed controller.