Distributed Parameter Modal Sensors

This paper deals with distributed parameter sensors designed with a view to extracting a vibration mode. Compared to conventional point-type sensors such as acceleration pickups, displacement sensors etc., the distributed parameter sensors have many benefits provided that they are properly designed. First, this paper overviews a conventional modal filter designed by use of point sensors, and enumerates the problems it involves. To overcome the drawbacks of the point sensor based modal filtering, a novel modal filtering technique based upon a PVDF film sensor, a distributed parameter sensor, is proposed. Two dimensional modal filters are discussed, and then, by taking into consideration a practicability of the sensors, a design procedure of one-dimensional modal filters is presented ; the number, location and shaping of the one dimensional sensors are clarified. Finally, an experiment is conducted, showing the capability of the distributed parameter modal filtering.