Identification of low-damping resonance characteristics and the high-bandwidth control of a piezo-positioning stage

The limitation of reducing low-damping resonance characteristics to the tracking bandwidth of a piezo- positioning stage was studied. Based on the linearization of the Prandtl-Ishlinskii inverse model, the impulse response- based Hankel matrix system identification method was applied to the identification of linear dynamic characteristics of the piezo-positioning stage, in which an improved method of correlation function calculation was proposed to further improve the accuracy of the identification of the low-damping resonance frequency band. Based on the transfer function model obtained by the identification, the zero-pole pair elimination method combined with an overshoot compensator was used to design a notch filter to compensate the low-damping anti-resonance and resonance characteristics, and the PI controller was designed based on the series trap to improve the closed-loop robustness and tracking performance. The experimental results show that the closed-loop bandwidth of the PI controller is 97 Hz, while the closed-loop bandwidth of the PI controller added with the notch filter is 244 Hz. Due to the addition of the notch filter, the closed-loop bandwidth is increased by 151.5%, thus illustrating the validity of the identification and control method. © 2024 Chinese Vibration Engineering Society. All rights reserved.