Cascade tracking control of servo motor with robust adaptive fuzzy compensation

Servo motor drive systems with high-accuracy position tracking control suffer from some uncertainties from inherent mechanical friction and varying end-load. In this paper, a novel cascade controller with feedforward robust adaptive fuzzy compensation is proposed to overcome the negative impacts of the uncertainties. An adaptive fuzzy logic system is used to estimate the friction, which is applied for designing a feedforward compensator to improve the tracking performance. Based on Lyapunov stability theory, we show that closed-loop system can ensure the semi-global asymptotic tracking performance. Our pro-posed compensation strategy takes advantage of utilizing the cascade P/PI controller with-out changing the original control system structure, which is practical and valuable to industrial applications. Simulation results indicate some merits of the proposed controll scheme in terms of the system stability, adaptivity and robustness with respect to different uncertainties. (c) 2021 Elsevier Inc. All rights reserved.