Electromechanical tuning of self-sensing piezoelectric transducers

The application of a self-sensing piezoelectric transducer included in a br idge readout network is here investigated taking into account the electrome chanical interaction. The parametric uncertainties and the piezoelectric de vice losses as well as the tolerances of the electric components make the b alancing of the bridge difficult to achieve in practice. A loss and uncerta inties compensation, based on a real-time software implementation of the br idge reference arm is here presented and validated. The standard electrical and the proposed electromechanical balancing are both theoretically and ex perimentally compared in the case of a simple beam. The bridge output signa l that is proportional to the strain rate is then fed back by means of a sh arp phase second order low pass filter which is aimed at increasing the dam ping of the first bending mode of the beam.