Adaptive Sliding-Mode Control with Self-Tuning Fuzzy Compensation for a Piezoelectric-Actuated X-Y-Z Table

摘要

This paper aims to develop and implement intelligent control for a X-Y-Z three-dimensional table using linear ultrasonic motors as the actuators. Functional approximation technique (FAT) is integrated with the sliding-mode control design to capture the unknown system dynamics and release the requirement of mathematical modeling. In order to deal with the approximation error and the uncertainties of the system, an adaptive fuzzy sliding-mode controller (AFSMC) is used as a compensation of the FAT-based sliding-mode control. Lyapunov stability theory is applied to assure the closed-loop stability and design the updating laws for weighting coefficients of Fourier series and fuzzy tuning parameters. Experimental results indicate that FAT-based sliding-mode control augmented with AFSMC compensation (FA+AFSMC) performs better than the solely FAT-based sliding-mode control.