Active friction-regulated inertia impact piezoelectric actuator.

In inertia impact piezoelectric actuators, the phenomenon of high-frequency drive-induced back-stepping poses a significant limitation to their overall performance. The ultra-fast response time of the piezoelectric stack enables the resolution of this issue. This paper introduces an inertia impact piezoelectric actuator operating under a novel Dual-Stack Motion Mode (DCMM), diverging from the traditional operation in the Single-Stack Motion Mode (STMM) that involves a solitary piezoelectric stack (PES) for active friction control. A comprehensive description of the actuator's structure and its operational principles under DCMM is provided. By constructing and experimentally evaluating the actuator using a controlled variable approach, a comparative analysis of performance between DCMM and STMM across various scenarios including different inertial mass blocks, driving voltages, frequencies, and load conditions was conducted. The experimental results indicate that DCMM significantly enhances the actuator's output performance, achieving a maximum speed of 1142.79 μm/s and a stable single-step displacement of 0.5 μm. The actuator features a simple yet effective structure and driving mechanism, allowing for multiple driving modes through the assembly of different inertial masses, thereby providing a substantial competitive advantage in output performance. The feasibility of using DCMM to improve actuator performance is corroborated by both theoretical and experimental studies. The ultra-fast response of the piezoelectric stacks expands the operational bandwidth of the actuator, achieving a seamless integration of speed and precision.