FAT-based adaptive sliding-mode control augmented with fuzzy compensation for a piezoelectric-actuated X-Y table system

In this paper, a model-free FAT-based adaptive sliding controller augmented with fuzzy compensator is proposed to control a piezoelectric-actuated X-Y table system. The control strategy employs the functional approximation technique (FAT) to capture features of the system dynamics and release the requirements of model knowledge prior to controller design. A fuzzy scheme with online learning ability is then augmented to compensate for the approximation error of FAT and other system uncertainties. To assure the closed-loop stability, update laws for the Fourier coefficients and fuzzy tuning parameters are derived based on Lyapunov stability theorem. Experimental results of the proposed scheme are compared to those of the solely adaptive sliding control without fuzzy compensation.