A purely centered and non-redundant piezoelectric stick-slip rotary stage with force amplification

Abstract

This paper proposes a purely center-rotation and non-redundant piezoelectric stick–slip rotary stage with force magnification. A bridge driving mechanism with centrosymmetric actuation feet is proposed, and its tilt angle can be adjusted to regulate the clamping force amplification characteristics, thus improving load capacities. Meanwhile, only a single piezoelectric actuator is used, and the driving mechanism is built in the circular slider, hence achieving non-redundant, purely centered rotation and improving the structural compactness. Theoretical calculations and simulation analyses of single-step rotation angles and force amplification of the rotary stage are carried out. In addition, a system dynamics model with electromechanical, rigid-flexible, and friction coupling properties is established. Finally, a prototype is fabricated, and various experiments are conducted. The designed bridge driving mechanism amplifies the piezoelectric actuation force by 2.8 times, and the stick–slip rotary stage has a maximum load of up to 9 kg. Also, the stage can rotate more than 360°, and the angular resolution is 0.1265 μrad, demonstrating superior performances of the non-redundant center-rotation stage.