RESEARCH ON VIBRATION CONTROL OF PIEZOELECTRIC FLEXIBLE STRUCTURES BASED ON SPATIAL NORMS

Using the definition of a spatial norm, the calculation formulas of modal spatial norms for structures are derived. In order to investigate the influence of the location of piezoelectric actuators on modeling dynamic equations and designing controllers for piezoelectric flexible structures, modal spatial norms, which serve as the measure of the contribution of modes to the dynamic response of a system varying with the location of piezoelectric actuators, are used to pick up the modes included in the reduction model. Based on the reduction model and compared with the traditional direct modes-truncation method, a dynamic output feedback H-infinity control law is designed to suppress the vibration due to external disturbances. Simulation results show that the contribution of vibration modes to the dynamic response of a system means the ability of actuators to control vibration modes, based on which the performance of a controller is improved.