基于TIADC的宽量程高精度流速测量

TIADC-based Current Measurement with Wide Range and High Accuracy

通过对声学多普勒测速理论的研究,结合时间交替采样(Time-interleaved Analog to Digital Converter,TIADC)结构,提出了一种无模糊并行复相关的测流方法.该方法首先对回波信号进行TIADC采样,并利用互谱插值估计回波信号的时延,粗测流速;然后结合TIADC多通道特性,采用并行复相关估计频偏量;再以时延测量流速作为修正依据,实现流速无模糊测量;最后进行实验验证.结果证明该方法不仅测速正确、测流量程大,而且精度高、抗干扰能力强.

In this paper, combined with time-interleaved analog to digital converter acquisition structure, a current measurement method without ambiguous boundary is proposed based on parallel broad-band complex correlation by studying the complex correlation algorithm and Acoustic Doppler current measuring theory. Firstly, TIADC is adopted to increase the sampling rate. Cross-spectral is used to estimate the time-delay of echo signal and to measure flow velocity roughly. Secondly, parallel complex correlation is applied to estimate frequency offset with TIADC characteristics. Further, the rough velocity is introduced to solve velocity ambiguity. Finally, the testing results show that the method can not only achieve correct flow velocity measurement of wide range, but also improve calculation precision with strong anti-interference performance.