压电式力传感器的低频补偿方法及实验验证

Low-Frequency Compensation Method of Piezoelectric Force Sensor and Experimental Verification

提出了一种压电式力传感器低频响应特性的补偿方法,该方法是在频域上完成的。首先,对压电式力传感器的输出信号进行后处理,将输出信号与补偿函数相乘即可获得补偿后的输出信号,其中,补偿函数是压电式力传感器放电时间常数的函数;然后,以P5H压电陶瓷片为例,分别对其施加已知的阶跃外力和低频简谐外力,并分别将补偿前后的测试结果与已知外力进行对比,从而实现对该方法的实验验证。验证结果表明:该方法可以对压电式力传感器的低频响应特性进行有效的补偿。

While the response properties of the piezoelectric force sensor in a high frequency band were good,its response properties in a low frequency band were poor.Therefore,in a low frequency band,the testing result of a piezoelectric micro-vibration testing platform consisting of piezoelectric force sensors wasunreliable.A compensation method was proposed to solve this problem.This method was completed in a frequency domain,which was the post-processing of the output signal of the piezoelectric force sensor.The output signal of the sensor after compensation should be the product of the output signal of the sensor before compensation and the compensation function,which was the function of the discharge time constant of the piezoelectric force sensor.Taking a P5 Hpiezoelectric ceramic piece as a piezoelectric force sensor,the method was verified by comparing the known forces with the testing results before and after compensation under the action of two different kinds of known forces,which were step force and harmonic force in a low frequency band.The results showed that this method can effectively compensate the response properties of apiezoelectric force sensor in low frequency band.