一种高精度压电换能器导纳仪的研究

压电换能器的一致性检测需要导纳圆测量仪器.给出了基于高速模数转换器和ARM7控制器的数字式压电换能器导纳圆测量系统.用ARM7控制生成不同频率的正弦信号,用高速A/D转换器同时采集两路原始测量波形,用数字信号处理方法处理原始波形的相位差和幅度比,从而得到导纳圆.与模拟式导纳仪相比,基于ARM控制器的数字式压电换能器导纳仪消除了低频滤波器的影响,能有效测量低频区域.与基于采集卡的数字式导纳仪和4294A测量结果对比显示,基于ARM7的导纳仪测量精度有了一定的提高.

Study on an Admittance Circle Measuring Instrument for High Accuracy Piezoelectric Transducer

The detection of the consistency of the piezoelectric transducer needs an admittance circle measuring instrument. The new generation of digital piezoelectric transducer admittance circle measurement system based on the ARM7 controller and high speed ADC is given. The sinusoidal signals of different frequencies are generated with the control of ARM7, the two way original measured waveforms are captured by high speed ADC simultaneously, and the phase difference and amplitude ratio of the original waveforms are processed by the digital signal processing method, then the admittance circle can be obtained. Comparing with the analog admittance circle, the piezoelectric transducer admittance circle measurement instrument based on ARM controller can eliminate the influence of the low frequency filter and can effectively measure the low frequency region. The experimental results show that, compared with capture card based admittance circle measuring instrument and 4294A, the accuracy of ARM7 based admittance circle measurement instrument has improved to some extent comparing with the capture card based admittance circle measurement instrument and 4294A measured results.