关键词: 局部应变, 同位配置, 正位移反馈, 速度负反馈, 振动

Abstract:

In order to overcome the problems resulting from the local strain in the collocated configuration of piezoelectric structure and the compensation damping ratio of the positive position feedback ( PPF) algorithm,first,a new method is proposed,which uses a low-pass filter to attenuate the local high-frequency strain mode and employs the direct velocity negative feedback ( DVFB) to modify the PPF algorithm for the damping ratio improvement. Next,the conditions for the stability of the improved algorithm are analyzed according to the Royce criterion. Then,by taking a plane panel structure as the objective,an experiment is carried out to verify the proposed method,in which a laser scanning vibrometer is used to identify the shape of the two modes and piezoelectric patches are pasted for vibration control. Simulated and experimental results show that,under either sine or random signal excitation,the method integrating low-pass filtering,PPF and DVFB greatly reduces the mode amplitude at 90 and 162Hz and effectively suppresses the harmonic component during the single PPF experiment,with a simultaneous control effect of the two modes being up to more than 10 dB.

Key words: local strain, collocated configuration, positive position feedback, direct velocity negative feedback, vibration