An active disturbance rejection controller with hysteresis compensation for piezoelectric actuators

Piezoelectric Actuators (PEAs) are the key components in nano-positioning. However, the inherent hysteresis nonlinearity of PEAs is seriously affected the control precision. In this paper, an active disturbance rejection controller is proposed to deal with the tracking control of PEAs. First, the hysteresis nonlinearity is reformulated as a disturbance of the closed-loop system. With this idea, a disturbance-based model is derived from the comprehensive model of PEAs. Then the so-called extended state observer is introduced to real-time estimate the hysteresis nonlinearity. With the extended state observer, the model of hysteresis or its inversion are all no longer needed. To verify the performance of the proposed method, some experiments are conducted on a commercial PEA. And the experiment results show that the proposed controller is an effective way to deal with the tracking control of PEAs.