New Discrete-Time, Fuzzy-Sliding-Mode Control with Application to Smart Structures

Anewdiscrete-time,fuzzy-sliding-modecontrollerwith applicationto vibrationcontrolofa smartstructurefeaturing a piezoe lm 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 convergenceto a sliding surface without extension of a sliding region, in which a system robustnesscannot 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 thenexperimentally realized,andcontrol resultsoftransient,forced, and random vibrationsof thesmart structure are presented to demonstrate the effectiveness of the proposed method.