基于相关法的低采样率超声水表时延估计方法

针对当前超声水表中相关法时间分辨率只能达到采样周期的问题,提出了一种基于相关法的低采样率超声水表时延估计方法.首先,研究了超声水表中所能达到的最大时间延迟;其次,讨论了相关法在超声水表当中的具体应用及插值算法对于提高流量测量精度的作用;最后,利用MATLAB软件对算法进行仿真评估了实际噪声条件下算法能达到的时延估计精度...

Low-sampling rate ultrasonic water meter time delay estimationmethod based on correlation method

Aiming at the problem that the temporal resolution of correlation method in ultrasonic water meter can only reach the samplingperiod, a time delay estimation method based on correlation method with low sampling rate is proposed. Firstly, the maximum time delayin ultrasonic water meter is studied. Secondly, the specific application of correlation method in ultrasonic water meter and the function ofinterpolation algorithm to improve the accuracy of flow measurement are discussed. Finally, MATLAB software is used to simulate thealgorithm and evaluate the estimation accuracy of the algorithm under the condition of actual noise, and the flow measurement system isbuilt to prove the effectiveness of the algorithm. The simulation results show that the average absolute error of time delay estimation iswithin 100 picoseconds when the frequency of ultrasonic transducer is 1 MHz and the sampling frequency is 4 MHz. It is shown that theproposed algorithm can achieve high precision delay estimation at low sampling frequency and is superior to the traditional correlationmethod in the accuracy of delay estimation.