基于惯性-摩擦驱动的球基微驱动器逆转现象分析

在压电陶瓷等效电学模型的基础上,结合外加驱动信号波形分析了基于惯性-摩擦驱动的球基微驱动器在工作过程中金属球产生逆转现象的原因,建立了金属球的转速及位移模型,采用快速放电回路和加速压电陶瓷放电的方法减小金属球的逆转位移及振动;利用压电陶瓷管作为微驱动元件,设计了基于惯性-摩擦驱动的球基微驱动器,并采用不同频率的三角波信号对所设计微驱动器进行试验测试.结果表明:驱动信号频率越高,微驱动器的振动现象越明显;当驱动信号频率接近、等于或大于微驱动元件(压电陶瓷管)的固有放电周期时,金属球出现无规律运动,导致微驱动器失效;根据1 Hz低频信号时的试验结果与计算所得结果基本吻合,证明了所建立的逆转理论模型的合理性.

Analysis of Back Rotation Phenomenon in Ball Base Microactuators Based on the Inertia-Friction Driving Principle

From equivalent electronic model of piezoelectric ceramic and driving signals waveform, reason which causes back rotation on metal ball of ball base microactuator in the inertia-friction driving process is analyzed, a rotate velocity model and displacement model of metal ball are set up in this paper. Designing a quickly discharging circuit to accelerate discharging of piezoelectric ceramic is put forward to decrease the back rotate displacement and vibration of metal ball, and then to enhance characteristics of microactuator. Finally, using three piezoelectric tubes as micro driving elements, a microactuator based on inertia-friction driving principle was designed and then experimented. Experimental data prove back rotation exists on the ball and the models are reasonable.