Experimental study for the optimal vibration control of composite beam and plate using piezoelectric film sensors and piezoelectric ceramic actuators has been performed. System parameters including natural frequencies, damping ratios, modal control forces and modal sensor constants have been determined from vibration tests and finite element method. Linear Quadratic Gaussian(LQG) control system has been designed, in which Kalman filter has been used as an observer and control gain has been determined to minimize linear quadratic performance index. The results of optimal vibration control have been compared with those of the classical control methods such as constant gain control(CGC) and bang-bang control(BBC). Optimal vibration control have shown the advantage in robustness to noise and control efficiency. For cantilevered composite plate with piezo-electric sensor and actuator, simultaneous control of the bending and twisting modes through optimal vibration control method is experimentally and successfully achieved.
