Micropositioning of 2DOF piezocantilever: LKF compensation of parasitic disturbances

Abstract

This paper presents a new control method devoted to improve the performances of 2-DOF piezoelectric actuator for precise positioning tasks. The piezoelectric actuator exhibits strong cross-couplings between its two axes and strong hysteresis and creep nonlinearities. These unwanted phenomena undeniably compromised therefore the final precision of the targeted tasks (micromanipulation) and should be conveniently accounted during the controller synthesis. In this paper, we proposed a combination of the discrete linear Kalman filtering with a closed-loop scheme to suppress the effects of the couplings and of the nonlinearities. The suggested method permits to improve the performances of the piezoelectric actuator without specific and detailed characterization and knowledges on the hysteresis and on the creep models. Extensive experiments were carried out with complex desired trajectories and demonstrate the efficiency of the novel approach.