A Rapid Dynamic Positioning Method for Settling Time Reduction Through a Macro–Micro Composite Stage With High Positioning Accuracy

A macro-micro composite precision positioning stage is mainly used in microelectronics manufacturing to achieve high-velocity and high-precision positioning. The residual vibration caused by high-speed macromotion will prolong the settling time and influence the working efficiency. This paper proposes a rapid dynamic positioning (RDP) method to quickly reduce the settling time of a macro-micro positioning stage by employing a designed spring-piezoelectric microstage. The main points of the RDP method are that it can start up the microstage at appropriate moment with proper extension to work against the macromotion vibration. Once the stage vibration amplitude is reduced to the piezoelectric element stroke limit, the micromotion is actuated to approach its final position. In this study, the start-up conditions and extension amount of the piezoelectric element were determined for implementing the RDP method. The feasibility of the method was clarified through theoretical analysis, including dynamic modeling, natural frequency analysis, and a vibration reduction and error compensation analysis. The experimental work was carried out, and the results validated the effectiveness of the RDP method in settling time reduction at different movements. With the assistance of the RDP method, the macro-micro high-speed, large-stroke stage can achieve an effective settling time reduction without sacrificing its accuracy.