Novel Method to Utilize Piezoelectric Film as Multi-mode Displacement Sensor and its Application to Active Vibration Control

摘要

Piezoelectric film is widely used as sensors to detect vibrations.In this paper,a novel method to utilize piezoelectric film as multi-mode displacement sensor is presented.First,fix any location of which the displacement is desired and the frequency response at the location is measured by any kind of displacement sensor.Then a specific location is chosen where the frequency response of stress possesses roughly proportional to the former frequency response of displacement.Pasting a piezoelectric film on the specific location and scaling its output so that it becomes identical to the output of the initial displacement sensor,the film could be used as a displacement sensor by which multi-modal vibration could be detected.To evaluate the validity of the presented method,two piezoelectric film sensors are applied to an experimental structure in order to perform active vibration control.The search method to find the specific location integrated with modeling method is presented and the two sensors are properly located.Control experiments with the two piezoelectric sensors located according to the method are performed,and the effectiveness of the piezoelectric sensors for active vibration control is investigated.