Time Delay Estimation of Ultrasonic Forward and Reverse Signals Based on Phase Difference

For the purpose of solving the problem that the starting point of the received waveform can not be determined and the pulse counting inaccuracy in the measurement of the actual ultrasonic transmission time, the All-phase phase difference time delay estimation method is proposed. Firstly, the All-phase spectrum analysis is carried out to obtain the phase difference of the forward and reverse ultrasonic signals; Then, according to the phase difference, calculating the time difference. For the ultrasonic flow meter, the time difference of the ultrasonic large flow data is obtained through the time delay estimation method, the verification results show that the All-phase phase difference time delay estimation method can effectively reduce the measurement error of ultrasonic transmission time, the error is about 0.1823us, thus improve the accuracy of ultrasonic flow meter.