Robust control of smart structures with optimally placed actuators and sensors

Abstract

The objective of this work is to design robust controller for smart structures to control its response under the influence of external excitation. An accurate model for the analysis of smart composite beams with surface bonded piezoelectric sensors and actuators patches is considered. Optimal placement of five piezoelectric sensor/actuator pairs are found, by exhaustively examining all possible configurations in order to suppress the first six modes of vibration. The LQR performance index is used as objective function to locate the sensor/actuator pairs. Vibration reduction for the cantilever beam with piezoelectric patches bonded in the optimal location was investigated to attenuate the first six modes of vibration using a Hinfinity scheme. After modeling multiplicative uncertainty, the augmented uncertain plant is obtained; an optimal robust controller is designed using Hinfinity. A robust controller is designed based on the augmented plant composed of the nominal model and it's accompanied uncertain. Robust and nominal performances of designed controllers are achieved for perturbed plants and results were compared.