双向驱动压电作动器结构设计
Structure Design of Bidirectional Piezoelectric Actuator

为了实现叠层压电作动器双向驱动、提高作动行程的目的，设计了利用三角位移放大原理的双向驱动压电作动器。分析了作动机构的运动及放大机理，建立了作动器的输出位移的理论模型和有限元静力模型。样机输出特性试验结果显示：压电作动器的位移放大倍数达5.45，与有限元仿真得到的放大倍数5.71以及解析计算得到的5.76倍相对偏差分别是4.77%和5.69%；驱动器在幅值为200V正弦电压的激励下，作动行程达105.5μm，作动行程与电压幅值具有很高的线性度（相关程度R2=0.997），且有很高的重复精度；作动器的输出特性受频率影响较小，频率每升高10Hz，作动振幅减小0.04μm；放大机构的迟滞效应相比单个叠层压电陶瓷有很大改善，迟滞回线中心对称。该结构实现了较大行程、双向对称驱动的目的，适用于需要往复驱动特性对称的应用场合。
A bidirectional driving laminated piezoelectric actuator is designed for reciprocating drive applications. It helps to improve the working range of the same kind of actuators based on the triangle amplification theory. The finite element model of the amplification mechanism’s driving mechanism is established for the static analysis and structure parameter optimization. The output characteristic test of the prototype shows that the amplification factor of the actuator reaches 5.45 and is 4.77% and 5.69% lower than that of the finite element analysis (5.71) and analytical calculation (5.76) respectively. The bidirectional initiative driving test shows that: the actuator move as long as 105.5μm under 200 Vpp(peak-to-peak voltage) sinusoidal voltage and the distance increases monotonically when the driving voltage rises with a high degree of linearity （R2=0.997）. The driving frequency has little effect on the characteristic of an actuator. The distance decreases by about 0.04μm per 10 Hz increment. The hysteresis effect of the advanced actuator combined the amplification mechanism is much better than that of laminated piezoelectric actuator alone. Besides, the hysteresis loop is symmetrical along the centerline.