Research on a slender piezoelectric micro-motion actuator and its application for high-speed and high-precision positioning

High-speed and high-precision micro-motion actuators (MMA) are crucial devices to promote development in micro-nano related fields. However, it is difficult to achieve both high-speed and high-precision characteristics for a single actuator. This study proposes a slender piezoelectric micro-motion actuator (PMMA), and a virtual model predictive control method is developed to achieve a balance between the rapidity and precision of MMA system. The output characteristics of the PMMA are simulated based on an improved finite element model and related algorithms, and the virtual model adopted by the controller is determined. Experimental results show that the virtual model has a low error, and the proposed control method successfully improves the positioning speed of PMMA. Compared with the traditional MMA system, the fast PMMA system has an operating range over 50 μm, and the side effects of high-speed positioning are mitigated: residual vibration can converge to within ± 5 % of the operating range in about 0.005 s, the converge speed is about 1200 times faster than the traditional PID control. In random positioning mission, the fast PMMA system has an average convergence time of 0.0041 s and precision of ± 0.16 μm, which is 3 times faster than the PMMA under ramp control. Moreover, different from ramp control, virtual model predictive control has no special requirements for positioning signal level and has a wider range of applications, such as micro-manipulation and imaging.