压电执行器位移自感知方法研究

在压电执行器闭环控制系统中，需要位移传感器提供位移反馈量．为了省略位移传感器，提出一种利用电子电路使压电执行器自感知其自身位移的方法．根据压电电荷几乎与位移成正比的特点，用电子电路获得驱动电荷，从电荷换算位移．提出了对压电执行器采取电压驱动和获取电荷为一体的复合驱动方法，高压运放输出作为高压驱动电源，电流积分器获得压电电荷．实验测量了带载和空载下压电双晶片和压电叠堆的自由位移，通过涡流位移传感器标定得到，双晶片位移自感知误差小于3．61％，叠堆位移自感知误差小于1．81％，实验测量了压电叠堆带载情况下的输出位移，结果表明可以用于带载位移自感知。

Research on displacement self-sensing method for piezoelectric actuator

Displacement sensor is essential to provide feedback in close-loop control of piezoelectric actuator. A displacement self-sensing method for piezoelectric actuator instead of displacement sensor is proposed. According to the fact that piezoelectric charge is nearly proportional to displacement, displacement is indirectly obtained from charge measured by electronic circuit called combined driving circuit. The combined driving circuit consists of high voltage power amplifier and current integrator. The high voltage power amplifier drives piezoelectric actuator, and the current integrator gets the charge but does not share the voltage applied to piezoelectric actuator. The free deformation of bimorph and the displacement of stack with and without load are tested and verified by independent eddy displacement sensor. Experimental results show that the bimorph displacement self-sensing error is within 3.61% and stack displacement self-sensing error is less than 1.81%. The method is suitable for the displacement monitoring of the stack under load.