High-Precision Tracking of Piezoelectric Actuator Using Active Disturbance Rejection Control

Piezoelectric Actuators (PEAs)are the crucial constituent components in high precision motion control of piezoelectric nano-positioning systems. However, its control precision is seriously restricted by the intrinsic rate-dependent hysteretic nonlinear characteristic. In this paper, by modeling PEA in a second-order disturbance-based structure, a novel active disturbance rejection control (ADRC)strategy is proposed to settle hysteresis compensation for tracking control of PEAs. Different from the prevailing direct model inversion method, which extremely depends on the precision of the detailed mathematical model of rate-dependent hysteresis, the proposed control methodology is model-free whereby hysteretic nonlinearity is treated as disturbance and rejected. Comparative experiments including extra tests using pure proportional-integral (PI)control without model inverse hysteresis compensation are implemented to demonstrate the performance of the proposed method on a PEA for 3 different types of signals. The promising experiment results manifest that the proposed ADRC scheme is better than pure PI control scheme in terms of control precision and tracking errors.