Optimal placement of piezoelectric actuators/sensors in active control of flexible structure

A new method of finding the optimal locations of piezoelectric sensors and actuators in active vibration suppression of flexible structure is presented based on the modal controllability and observaibility. The basic equations of the flexible structure bonded with piezoelectric sensors/actuators is derived. Utilizing the orthogonal projection of structural modes into the intersection subspace of the controllable and observable subspaces to reflect the degrees of controllablity and observability, the optimal placement indices of the candidate actuators/sensors locations are obtained by means of the degree of controllability and observability properly weighted according to the modal contribution to output of system. The simulation results show that the vibration of flexible structure can be suppressed efficiently by using the optimized actuators/sensor.