Modeling and active disturbance rejection control for a piezoelectric-actuator driven nanopositioner

This paper investigates the modeling and control problem of a novel piezoelectric-actuator (PZT) driven nanopositioner. The physical model of the nanopositioning stage is first discussed with the hysteresis nonlinearity of the PZT actuator. For the purposes of eliminating the hysteresis impact and various disturbances, an active disturbance rejection control (ADRC) algorithm is proposed, where the nonlinear dynamics of the model and external disturbances are treated as “total disturbances” which can be estimated by an extended state observer (ESO) and then compensated by a state feedback control law. The proposed algorithm is deployed in real time implementations on a nanopositioning servo platform and demonstrates good control performance in terms of high precision positioning and hysteresis elimination.