通过PVDF阵列测量体积位移的实验研究

针对目前PVDF体积位移传感器的研究主要集中在经典边界条件(如简支、固定、自由等)、需要预知精确的边界条件等不足,提出通过伪逆方法结合Tikhonov正则化方法设计振动梁在任意未知边界条件下的压电式体积位移传感器的通用设计模型.以一未知边界条件的振动梁为例,用一组PVDF阵列测量其体积位移.在该梁表面均匀粘贴一组相同形状的矩形PVDF薄膜,然后通过所提出的新方法设计这组PVDF输出信号的加权系数,从而得到体积位移.实验结果表明这种传感器设计方法是可行的,并且不需要预知振动梁的边界条件或模态信息.

Experimental research on the volume displacement sensor using PVDF array

Notice that the theory for designing piezoelectric volume displacement sensors is limited to classical boundary conditions (i.e., either simply supported, clamped or free). Furthermore, Most current published research on piezoelectric volume displacement sensors relies on precise knowledge of the boundary conditions of the structures. In this paper a solution to the problem of designing the volume displacement sensor for a beam with arbitrary unknown boundary conditions is proposed, using the pseudo-inverse approach combined with Tikhonov regularisation method. With an example of a vibrating beam under unknown boundary condition, this paper presents a new analytical and experimental wok that is to sense volume displacement by an array of PVDF sensors. An array of rectangular segments of PVDF film equally attached on the surface of the beam is taken as sensor. The output signals of the PVDF films are multiplied by appropriate weights which are determined by the proposed method, so that the weighted combinations of the outputs directly lead to the volume displacement of the beam. The PVDF weights are calculated from the experimental PVDF responses in frequency domain. The experimental results show that the proposed method for the design of the weight of each PVDF film sensor does not need the information of structural modes of the beam.