A compound control method of hysteresis nonlinearity and dynamic behavior in piezo-based scanning systems

A compound control method was developed by integrating the closed-loop force feedback and the input shaping method to overcome the problem of the hysteresis and dynamic behavior in piezo-based scanning systems (PSS). The flexible mechanism and PEA were analyzed, and the dynamic model of the scanning systems was established. A force sensor and an integral controller were utilized in force feedback to directly augment the damping of the PSS. For the further control of mechanical resonance, based on the theory of minimum-acceleration trajectory planning, a time-domain input shaping method was developed. The turning sections of a scanning trajectory were replaced by smooth curves, while the linear sections were retained. The force feedback method was combined with the input shaping method to control the nonlinearity and mechanical resonance in high-speed PSS. The experimental results show that the tracking error at 50 Hz is reduced from 9. 33% to 1. 87% by the compound control method. Compared with the open-loop displacement response, the tracking accuracy of the system was improved by about 4 times. Compared with the closed-loop control method using only force feedback, the tracking accuracy of the system was improved by about 1. 6 times. © 2024 Chinese Vibration Engineering Society. All rights reserved.