时差法作为一种传统的测流原理，由于存在安装难度大、机械制造精度要求高和时间截取准确度要求高等因素，造成时差法测流存在一些不确定性，可能无法实时准确地反映水层的瞬时流速。针对上述问题，运用超声波多普勒效应，即水层与流速仪存在相对运动时，声波的反射信号将产生相应的多普勒频偏，研究并设计了一套完整的以STM32F407VGT6为核心处理芯片的超声波发射电路和微弱超声波信号接收处理电路，介绍了基于复调制的ZoomFFT的基本原理，同时成功地运用到了管道流速测量的算法当中，并取得了良好的测试效果。%As the traditional principle of flow measurement , with the factors of installation difficulty , high precision in ma-chinery manufacturing and fine time-intercepting requirement , the time difference method has some uncertainty , resulting in inac-curate reflecting in real-time instantaneous flow rate of the aqueous layer .Aiming at the above problems , the ultrasonic doppler effect was used , that is, when there is a relative motion between water layer and flow measuring instrument , sound waves reflected signal will produce a corresponding doppler frequency shift .A complete ultrasonic transmitter circuit and weak ultrasonic signal re-ceiving circuit were researched and designed with STM 32F407VGT6 core processing chip .The basic principle of ZoomFFT based on complex modulation was successfully applied to the pipeline flow measurement algorithm ,thus a chieving good test results .
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