数字信号处理技术在高含沙量流体流量计中的应用

Application of Digital Signal Processing to High Sand Content Fluid Flowmeter

笔者采用数字手段去测取超声波信号的频差 ,通过频差法可得出流体的平均速度 ,进而获得高含沙量流体的流量。数字信号处理技术首先必须将回波信号的平均频率参数离散化。在计算的过程中 ,一般采用DFT处理技术 ,但直接用DFT进行谱分析和信号实时处理又不切实际 ,所以我们使用了分裂基FFT。本文编写了基于分裂基FFT算法的频谱计算程序 ,并设计了基于DSP(TMS3 2 0F2 0 6)的硬件系统 ,对含沙量 2 0 %的渠水进行实测取得了令人满意的结果 ,精度可达 99%。

A digital signal processing way is established to obtain ultrasonic signal frequency shift in the test of high sand content fluid flow. The average velocity of fluid is derived by frequency shift and the volume of flow is further obtained. The program based on Fen Li Ji FFT algorithm to analyze the frequency spectrum and the DSP (TMS320F206) hardware system are designed. The accuracy rate gets 99% in our practice testing the fluid with the sand content as high as 20%.