Design, analysis and experimental performance of a piezoelectric rotary actuator based on compliant foot driving

This study proposes a piezoelectric rotary actuator based on compliant foot driving. With the help of driving modules which are composed of four compliant feet and four piezo-stacks, the designed actuator can produce large range rotary motions in both forward and backward directions with a high resolution. The mechanical structure and the moving principle are presented. Pseudo-rigid-body model is used to simulate the path of the compliant foot end and the movement model of the driving module is established to analyze the motion of the actuator. The influence of the preload force on performance of the actuator is discussed. To investigate the working performance, a prototype is fabricated and a set of experimental system is established. The experimental results indicate that the angular displacement outputs under various driving voltages and frequencies show good linear relationships with the time. The driving resolution and the maximum output force are 0.24 µrad and 158 N, respectively. The angular displacements deviation between the forward and backward motions within 50 steps is 376.4 μrad and the actuator can achieve various angular velocities by changing the driving voltage and frequency.