一种应用于超声波测量的混频检相方法

A Mixer Phase Detection Method Applied to Ultrasonic Measurement

为了提高超声波测量系统的精度,加快检测速度,对超声波测量系统提出了一种混频检相方法并完成了混频检相器的设计。采用混频方法将两路有一定相位差的被测信号与另一路有较小频差的信号混频,混频后通过低通滤波电路滤除高频成分,得到保留原信号相位差的两路低频信号,通过整形电路获得两路方波信号,采用由D触发器设计的检相电路对两路方波信号进行相位差检测。对该混频检相方法进行了仿真和多组相位差实验验证。结果表明,该混频检相方法具有电路简单、测量精度高、成本低等优点。

In order to improve the accuracy of the ultrasonic measuring system and speed up the detection,a mixing phase detection method for the ultrasonic measuring system is proposed and the mixing phase detector is designed.Two signals with certain phase difference are mixed with one signal with a small frequency offset.The mixed signals are processed through a low-pass filter to remove the high frequency component,and get two low frequency signal with the orginal phase difference.The shaping circuit is adopted to process the mixed low frequency signals to get two square wave signals,and the phase-checking circuit designed from D flip-flop circuit is utilized to check the phase difference between these two square signals.The simulation and multi group phase difference experiments are carried out to verify the phase detection method.The results show that the method has the advantages of simple circuit,high measurement accuracy and low cost.