Active Vibration Control and Fault Detection of Smart Structures(International Workshop on Smart Materials and Structural Systems, W03 Jointly organized by Material & Processing Division, Material & Mechanics Division, Dynamics & Control Division and Space Engineering Division.)

Abstract

Experimental researches on active control of smart structures with piezoelectric actuators have been conducted in the laboratory. The major objective of the researches is to develop a robust and reliable control system for smart structures considering system uncertainties such as structural parameter errors and system failures. Two topics are introduced in this paper. One is the study on a discrete-state sliding mode control (SMC) for vibration control of smart structures. The discrete-state subspace system identification (4SID) is used in combination with the discretestate SMC design, and a software module for seamless transformation from discrete system to continuous system has been developed. The proposed discrete-state sliding mode control has been applied to the flexible cantilever beam equipped with a piezoelectric actuator. It is shown both by numerical simulations and by hardware experiments that the discrete-state SMC has high performance of vibration suppression and robustness against system uncertainties. The second topic is a new method for the fault detection and health monitoring of smart structures. The Eigensystem Realization Algorithm (ERA), a time-domain system identification algorithm, is applied to detect system failures by monitoring the estimated eigenvalues of the system matrix. The ERA is a powerful tool for detecting the small variation in the stifftiess parameter that indicates a structural damage.