On Disturbance Rejection of Piezo-actuated Nanopositioner

This paper concentrates on the active disturbance rejection control of a nanopositioner driven by a piezoelectric actuator. Hysteresis reduces the accuracy or even breaks the stability of a nanopositioner. For the purpose of improving the closed-loop performance of a nanopositioning stage, active disturbance rejection control (ADRC) is utilized. Fourth order extended state observer is designed to get system output, first and second derivative of system output, and the total disturbance. System performance can be guaranteed by compensating total disturbance via control law. Based on an identified model of a nanopositioning stage, simulations have been performed. Numerical results have been presented to confirm the ability of ADRC in high-precision positioning.