拟用压电陶瓷执行器自感知位移,省去外部传感器.从基本压电方程出发,推导出压电陶瓷执行器晶片上自由电荷中包含的执行器位移信息,进而提出了一种基于积分器电路的压电陶瓷执行器位移自感知方法.对压电陶瓷叠堆执行器设计了电压驱动电路,同时设计了获取自由电荷的积分器电路.基于此复合电路,执行器在执行的同时,可以感知其自身的位移.该方法使得自感知电路的调节和感知信号的获取变得容易,克服了电桥法自感知电路阻抗不易匹配的不足.实验结果表明,在不同的驱动电压波形、不同的驱动电压频率下,基于积分器的压电陶瓷自感知执行器均能够很好地获取执行器的位移信号.
This study aims at making piezoelectric ceramic actuator self-sense its own displacement in the absence of independent sensors. It is inferred from the constitutive piezoelectric equation that the free charge on the wafer of piezoelectric ceramic actuator contains the displacement information. So a compound circuit-based displacement self-sensing is developed, where piezoelectric ceramic actuator is driven by the part of voltage-generating and the resulting free charge is obtained through the integral part. Based on the proposed compound circuit the actuator can sense its own displacement while actuating. It is convenient to adjust the circuit and easy to ac method, and there is not the impedance mismatching problem met qui in re sensitive signal by using this bridge-based self-sensing circuit. The experimental results show that piezoelectric self-sensing actuator can effectively measure its displacement signal under the conditions of different wave forms of driving voltage and different driving voltage frequencies.