Hysteresis Modeling and Combined Control of Piezoelectric Actuators with the Amplitude-Dependent Behavior

The piezoelectric actuator is widely used in precise measurement, micro-nano instruments and vibration suppression control since it can achieve nanometer positioning precision. However, its hysteresis seriously affects positioning accuracy. Most research focuses on its frequency-dependent behavior and proposes many related methods. We find that the hysteresis will be more severe as the amplitude of the driving signal increases, named amplitude-dependent behavior. Thus, the paper proposes a new amplitude-dependent Prandtl-Ishlinskii model to describe the hysteresis accurately. A feedforward controller based on the inverse model is designed to compensate for the hysteresis errors. To further reduce the positioning errors induced by other system errors, an amplitude dependent feedback controller based on a fuzzy controller is designed. Experiments show that the combined controller can effectively improve its positioning precision by at least 56% compared with the traditional proportional-integral controller.