A three-degree-of-freedom piezoelectric actuator with sandwich structure: Design, modeling, and experiment

Abstract

With the increased motion requirements of precision drive devices, multi-degree-of-freedom piezoelectric actuators have become key technologies for realizing multi-axis motion control. To expand upon the three-degree-of-freedom piezoelectric stick-slip driving method, a sandwich-type three-degree-of-freedom rotating inertial stick-slip piezoelectric actuator is proposed in this paper. Firstly, the structure and control strategy of the actuator were introduced. Statics analysis of the core component of the piezoelectric vibrator was carried out, and the relationship between the structural parameters and the deformation of the driving foot was obtained. Then the free and forced vibrations of the piezoelectric vibrator are analyzed to determine the dynamic response of the driving foot in the time domain. Finally, a prototype was fabricated and an experimental system was built to test its output characteristics. The test results show that when the driving voltage was 150 V and the frequency was 320 Hz, the proposed actuator achieves maximum speeds and load torques around the x-axis and y-axis of 306 mrad/s and 2 mN m, respectively. When the driving voltage was 150 V and the frequency was 450 Hz, the proposed actuator achieves a maximum speed and load torque around the z-axis of 140 mrad/s and 1.55 mN m, respectively.