High-precision Allogeneic Transceiver Ultrasonic Ranging System Based On Phase Detection

In this paper, we propose measurement scheme based on a single stationphotoelectric scanning angle measurement combined with ultrasonic ranging bydiscussing the limitations of multi-station positioning system measurementapplications in the industrial field optical scanning by analyzing wMPS.Afterconsidering the measuring range, measurement accuracy, and application contextpremise, we proposed a scheme based on ultrasonic ranging cross-correlationmeasurements combined with coarse delay estimation FFT measurement precisionphase detection method.The main contents include:(1) We achieve relative distance measurement function by propose an ultrasonicdelay estimation algorithm based on cross-correlation signal processing. The subjectmake two improvements compared with the traditional cross-correlation delayestimation: First, we reduce the computation and the amount of data sampling byincreasing the peak envelope detection module receives a pre-estimated wave arrivaltime as the open A/D sampling time base module.Second, the feature points of thetransmitted signal design, build cross-correlation mathematical model to calculate thereference signal.(2) We research and implement ultrasound distance precision measuring methodwhich based on FFT algorithm phase estimate. This method is essentially a sequenceof discrete do DFT transform, discrete sequence of early phase DFT-calculated basedon the relationship of the ratio of the imaginary part of the phase angle and the realpart.(3)Wavelet de-noising. The wave processed by wavelet de-noising before thecross-correlation and the FFT phase detector. Comparing with the traditional low-pass, band-pass filter, the wavelet de-noising perform better in preserving the usefulsignal. The wavelet de-noising can improve the accuracy of the final measurement.(4) We compensate the speed of the sound by analysis the effect of temperaturefactors on the accuracy of ultrasonic ranging.