Abstract
A smart structure is composed of the piezoelectric film sensors and actuators in order to reduce the structural vibration. H_2 controller is designed with the reduced order model of the smart structure which is obtained by finite element and modal analyses. The control forces are applied by the piezoelectric film actuators and the feedback signals are detected by the piezoelectric film sensors or the accelerometers in the system. The modal control and the displacement control with the appropriate actuator placement are conducted by selecting the modal coordinates and the spatial displacement as the controlled response, resulting in the effective vibration reduction. Efficient optimization algorithm based on a two step procedure is employed in the simultaneous optimization of structural/piezoelectric shape and H_2 control system. It is verified by some applications that the enhanced performance for the vibration suppression can be achieved by the simultaneous optimization.
