Modelling of a piezoceramic patch actuator for velocity feedback control

Abstract

This paper discusses the modelling of a thin panel with a velocity feedback controlunit, which is formed by a piezoceramic patch actuator and, at its centre, anideal point velocity sensor. The model has been used to predict the open loopsensor–actuator frequency response function in a wide frequency band, up to 80 kHz, sothat the stability of the feedback control loop can be properly assessed usingthe Nyquist criterion. In particular the inertia and stiffness effects produced bythe actuator on the frequency response function have been analysed. Simulationresults have highlighted that the inertia effect produces amplitude reduction andphase lag at higher frequencies. The stiffness effect reduces the amplitude at lowfrequencies, decreases the phase lag at higher frequencies and produces an amplitudemodulation effect at higher frequencies. Comparison with a measured frequencyresponse function indicates that the proposed model has captured the principalcharacteristics of the sensor–actuator open-loop frequency response function up to 80 kHz.