Development of a Nanopositioning Platform With Large Travel Range Based on Bionic Quadruped Piezoelectric Actuator

A piezoelectric platform driven by a bionic quadruped piezoelectric actuator is developed. It uses the operating principle of combining bionic walking and swinging actuation modes to achieve nanopositioning in a large travel range. The mechanical structure is introduced, the operation principle is illustrated, and the dynamic model and control method are developed. The open-loop performances are first tested to verify the effectiveness of the operating principle and the dynamic model, and the simulation results agree well with the experimental results. Then, the closed-loop experiments in bionic walking and swinging actuation modes are carried out, respectively, and the controllers are designed based on the dynamic model. In the point-to-point positioning control experiments, the steady-state errors for the target position of +/- 1000 mu m in axes X and Y are within +/- 1 mu m in bionic walking actuation mode, and they are within +/- 20 nm for the target position of +/- 2 mu m in bionic swinging actuation mode. The closed-loop experiments under the combination of the bionic walking actuation mode and swinging actuation mode are performed, and a switched controller is developed to obtain the switching of the two modes automatically; the steady-state errors are within +/- 20 nm. The experimental results confirm that the method combining bionic walking and swinging actuation modes and switched control is valid in enhancing the positioning precision and travel range for the nanopositioning platform.