Tanaka N.

Modal-based control can be placed into two categories: high authority control (HAC) and low authority control (LAC). Regarding HAC, when attempting to suppress the vibration of a distributed parameter structure, the method encounters difficulty in control because of a large number of modes it involves; modal-based control theoretically requires as many sensors / actuators as the number of modes controlled. On the contrary, LAC that is mostly implemented using velocity feedback (DVFB) with collocated sensors and actuators treats all structural modes equally, and is not able to preferentially damp modes that are more bothersome while ignoring modes that are inconsequential to the final result. This paper concerns modal control of a rectangular panel using smart actuators that enable the actuation of a target mode without causing any effect on other structural modes. Compared to conventional point-based actuators, distributed parameter actuators presented in the work possess significant benefits provided that they are properly designed. First, a background of modal control based upon the distributed actuator as well as a combination of distributed actuator and a point sensor is outlined. Three dimensional modal actuation using PVDF film is, then, presented. Furthermore, taking into consideration a practicability of the actuator, a two-dimensional smart modal actuator is presented, the number, locations and shaping function for the optimality of the actuator being clarified. Moreover, an experiment is conducted, showing the capability of the distributed parameter modal actuator. Finally, a feedback control system is constructed utilizing the smart actuators, demonstrating the effectiveness for suppressing the particular structural mode of interest without causing any spillover problems.