基于FPGA+ARM的压电换能器阻抗测量系统设计

Design of Admittance Measurement System of Piezoelectric Transducer Based on FPGA and ARM

该文研制了一种基于现场可编程门阵列(FPGA)和ARM的压电换能器阻抗测量仪,介绍了矢量伏安法的阻抗测量方法,从压电换能器的等效电路出发,分析了换能器阻抗测量方法。设计了基于FPGA的直接数字式频率合成(DDS)信号发生电路,阻抗测量前端和相敏检波电路。通过ARM系统实现了换能器等效参数计算和导纳圆显示。实验表明,该装置结构简单,测量精度可靠,满足工程应用。

An admittance measurement instrument of piezoelectric transducer based on FPGA and ARM was developed in this work.The principle of vector voltammetry for impedance measurement was introduced.Considering the equivalent circuit of piezoelectric transducer,the transducer impedance measurement method was analyzed.The DDS signal generating circuit based on FPGA and the phase sensitive detection circuit were designed.The equivalent parameter calculation and admittance circle display were realized by using the ARM system.The experimental result shows that the proposed device has the features of simple structure and reliable measurment accuracy,and can satisfy the requirements for engineering applications.