基于超声流量计的包络互相关时延理论及仿真

摘要

Aiming at the problems of the difficulty of determining the peak value of cross correlation function for ultrasonic flow meter and the complexity of calculation, the last speed algorithm based on FFT for directly extracting envelope of correlation function is used. The physical measurement model is established for ultrasonic flow meter, and the mathematical model is derived, then by adopting the method based on FFT, the envelop of correlation function is extracted directly. The result of Matlab simulation verifies that this method does accurately extract the envelop of correlation function and search the peak value of correlation function, thus greatly improve the accuracy of ultrasonic flow meter.%针对超声波流量计存在的互相关函数法峰值确定难、运算量大等问题,采用了一种基于傅里叶变换(FFT)的直接提取相关函数包络的快速算法.对超声波流量计建立了物理测量模型,并得出数学模型,然后利用基于FFT方法直接提取相关函数包络.Matlab 仿真结果证明,该方法能精确提取相关函数的包络,并搜索到相关函数的峰值位置,从而大幅度提高超声波流量计的精度.