LAUSR

The hysteresis of the piezoelectric actuator (PEA) exhibits obvious rate dependence, especially in fast scanning or tracking. This paper proposes an adaptive hysteresis compensation method that integrates the direct inverse modeling (DIM) method and an adaptive Kalman filter (AKF). DIM is adopted to directly obtain the inverse hysteresis model and use it as the hysteresis compensator. AKF is utilized to dynamically update the weights of the inverse hysteresis model so as to eliminate the manual tuning of control parameters. Further, a forgetting factor is adopted in AKF to reduce the influence of the old data. Experimental results on tracking of step, sinusoidal and triangular trajectories demonstrate the effectiveness of DIM+AKF in hysteresis compensation. The transient and steady state performances of the closed-loop system are significantly improved. A closed-loop bandwidth higher than 200 Hz is achieved. The robustness of DIM+AKF against the rate dependence is further verified using a 0-200 Hz swept sinusoidal trajectory. As the on-site tuning is successfully eliminated, DIM+AKF is easy to follow for experienced users.