Abstract:

The adaptive identification of the non-linear hysteresis and creep effects in a piezoelectric actuator is proposed in this paper. Model uncertainties related to the hysteresis and creep effects in piezoelectric actuators, most prominently in the high frequency zone (to 100 Hz), can make the closed-loop control system unstable. Furthermore, it may lead to inaccurate open-loop control, frequently causing harmonic distortion when the piezoelectric actuator is driven with a sinusoidal input voltage signal. In order to solve the above issues, it is important to determine an accurate, non-linear dynamic model of the piezoelectric actuator. An Unscented Kalman Filter (UKF) based adaptive identification algorithm is presented that accurately determines the dynamic model of a piezoelectric stack type actuator such that the non-linear hysteresis and creep effects can be accurately predicted. Since hysteresis and creep are dominant in open-loop, the actuator is driven in an open-loop mode in this investigation.