Adaptive fuzzy sliding-mode control for electrical servo drive

In this study, an adaptive fuzzy sliding-mode control (AFSMC) system with an integral-operation switching surface is adopted to control the position of an electrical servo drive. The AFSMC system is comprised of a fuzzy control design and a hitting control design. In the fuzzy control design a fuzzy controller is designed to mimic a feedback linearization (FL) control law. In the hitting control design a hitting controller is designed to compensate the approximation error between the FL control law and the fuzzy controller. The tuning algorithms are derived in the sense of the Lyapunov stability theorem, thus the stability of the system can be guaranteed. Moreover, to relax the requirement for the bound of approximation error, an error estimation mechanism is investigated to observe the bound of approximation error real-time. Experimental results verify that the proposed control systems can achieve favorable tracking performance and robust with regard to parameter variations and external load disturbance. c © 2003 Elsevier B.V. All rights reserved.