Modeling of hysteresis in piezoelectric actuator based on adaptive filter

Abstract

A novel adaptive transversal filter modeling is presented for the hysteresis characteristic in PEA (piezoelectric actuator). First, the hysteresis modeling capability of delay operator based adaptive transversal filter is explored. On this basis, delay operators of adaptive transversal filter are replaced with Backlash operators to compose a new serial structure of adaptive transversal filter model, and LMS (least mean square) algorithm is used to adjust the weight values. And then, as LMS algorithm brings a serious confrontation of the convergence speed and steady-state offset, a new improved adaptive method focus on the convergence factor is brought in. The new filter with this improved algorithm makes the contradiction of convergence speed and steady-state offset could be unified to some extent. At last, the two adaptive transversal filters are applied to model for hysteresis characteristic of PEA, and the modeling effect is verified via a micro-positioning system experiment platform based on PEA. Experimental results show that the proposed Backlash operator based adaptive filter can achieve accurate hysteresis modeling, and the effectiveness of the improved adaptive algorithm is also demonstrated.