Active vibration control of a cantilevered plate instrumented with piezoelectric patches: Robust to variations in electric field

Piezoelectric coefficient and dielectric constant of PZT-5H vary with electric field. In this work, variations of these coefficients with electric field are included in finite element modelling of a cantilevered plate instrumented with piezoelectric patches. Finite element model is reduced using modal truncation and then converted into state-space. First three modal displacements and velocities are estimated using Kalman observer. Negative first modal velocity feedback is used to control the vibrations of the smart plate. Two cases are considered: 1. In which variation of piezoelectric coefficient and dielectric constant is considered in Kalman observer 2. In which variation of piezoelectric coefficient and dielectric constant is not considered in Kalman observer. Simulation results show that appreciable amount of error in simulation would be present if variation of these coefficients with r.m.s. value of electric field is ignored.