Sliding-mode enhanced adaptive motion tracking control of piezoelectric actuation systems for micro/nano manipulation

This paper proposes a sliding-mode enhanced adaptive control methodology for piezoelectric actuation systems to track specified motion trajectories.. This control methodology is proposed to overcome the problems of unknown or uncertain system parameters, nonlinearities including the hysteresis effect, and external disturbances in the piezoelectric actuation systems, without any form of feedforward compensation. In this paper, a special class of positive definite functions is employed to formulate the control methodology such that the closed-loop system stability can be guaranteed. The control formulation, stability analysis, and analytical closed-loop solution are presented. Furthermore, a precise tracking ability in following a specified motion trajectory is demonstrated in the experimental study. With the capability of motion tracking under the aforementioned conditions, the sliding-mode enhanced adaptive control methodology is very attractive in realising high-performance control applications in the field of micro/nano manipulation.