New discrete-time, fuzzy-sliding-mode control with application to smart structures

A new discrete-time, fuzzy sliding-mode controller with application to vibration control of a smart structure featuring a piezofilm actuator is presented. First, a discrete-time model with mismatched uncertainties is considered for the design of a discrete-time, sliding-mode controller, which consists of an equivalent part and a discontinuous part. In the design of the equivalent part, an equivalent controller separation method is adopted to achieve faster con, convergence to a sliding surface without extension of a sliding region, in which a system robustness cannot be guaranteed. The discontinuous control part is then constructed on the basis of the sliding and convergence conditions. Subsequently, the discrete-time, fuzzy-sliding-mode controller is formulated by employing a fuzzy technique to appropriately determine principal control parameters such as a discontinuous feedback gain. The controller is then experimentally realized, and control results of transient, forced, and random vibrations of the smart structure are presented to demonstrate the effectiveness of the proposed method.