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 uncertaint ies is considered for the design of a discrete-time, sliding-mode cont roller, which consists of an equivalent part and a discontinuous part. In the design of the equivalent part, an equivalent controller separa tion method is adopted to achieve faster con, convergence to a sliding surface without extension of a sliding region, in which a system robu stness cannot be guaranteed. The discontinuous control part is then co nstructed on the basis of the sliding and convergence conditions. Subs equently, the discrete-time, fuzzy-sliding-mode controller is formulat ed by employing a fuzzy technique to appropriately determine principal control parameters such as a discontinuous feedback gain. The control ler 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.