Modeling and control of rate-dependent hysteresis for a piezo-driven micropositioning stage

Piezoelectric hysteresis usually relies on the frequency of the input signal. Most of the existing rate-dependent models use a lot of parameters to capture the rate-dependent hysteresis. In this paper, a simple rate-dependent hysteresis model is proposed to describe the frequency dependency effect of a micropositioning stage driven by piezoelectric actuators. This model is extended from an enhanced Coleman-Hodgdon (C-H) model. It has only 9 parameters and exhibits an accuracy better than 97%. The dependencies of the model parameters on the input rate are derived based on open-loop experimental tests. As inverse rate-dependent C-H model is established to construct a feedforward compensation. Experimental results demonstrate the effectiveness of the rate-dependent model over the traditional rate-independent one. The feedforward in conjunction with a PID feedback control is constructed to further attenuate the modeling errors and creep effects. Results show that the combined control scheme suppresses the tracking error by more than 8 times compared to the stand-alone PID control. It provides a sound base of practical control of the micropositioning system for micro/nano scale manipulation.