Enhancement of micro-positioning accuracy of a Piezoelectric positioner by suppressing the rate-dependant hysteresis nonlinearities

Compensation of rate-dependent hysteresis nonlinearities of a Piezoelectric positioner is carried out by integrating the inverse of the rate-dependent Prandtl-Ishlinskii model as a feedforward compensator. The proposed compensator was subsequently implemented to the positioner hardware in the laboratory to study its potential for rate-dependent hysteresis compensation on a real-time basis. The experimental results obtained under different excitation frequencies revealed that the integrated inverse compensator can substantially suppress the hysteresis nonlinearities in the entire frequency range considered in the study. The proposed inverse model compensates for the rate-dependent hysteresis nonlinearities without using the feedback control techniques.