Preload Force Optimization and Evaluation of Double-Stator Piezoelectric Inertial Actuators

Double-stator inertial piezoelectric actuator has better performance than the single-stator inertia piezoelectric actuator, and has received extensive attention. The preload force has a great influence on inertial piezoelectric actuators, since the motion of the actuator is based on the principle of static friction and sliding friction. Although many designs of double-stator inertial piezoelectric actuators have been designed, there is still less research on the influence between preload force and output performance. To study the influence of preload force, a series of analyses, modeled, and experimental investigations are carried out in this paper. A double-stator inertial piezoelectric actuator with real-time detection of preload force is proposed and its operation principle is presented. Experimental investigations are carried out on the actuator prototype, and the experimental results show that: changing the preload force has a very weak effect on the optimal frequency; with the increase of the preload force, the speed of the actuator will decrease, and the thrust will increase significantly, but there is an optimum preload force; with the increase of preload force, the load capacity of the actuator will be significantly improved. This study provides guidance for the selection of preload force parameters for double-stator inertial piezoelectric actuators, such as selecting a smaller preload for high-speed-low-load actuators and a larger preload for low-speed-large-load actuators.