Accuracy and resolution of ultrasonic distance measurement with high-time-resolution cross-correlation function obtained by single-bit signal processing

摘要

Distance measurement using an ultrasonic wave is suitable for environment recognition inautonomous mobile robots. Ultrasonic distance measurement with the pulse-echo method is based onthe determination of the reflected echo's time of flight (TOF). Pulse compression can improve distanceresolution and the reflected echo's signal-to-noise ratio (SNR). However, calculation of crosscorrelation requires high-cost digital signal processing. A sensor signal processing method of crosscorrelation using a delta-sigma modulated single-bit digital signal has been proposed. Crosscorrelation by single-bit signal processing reduces the calculation costs of cross correlation.Furthermore, cross correlation by single-bit signal processing improves the time resolution of thecross-correlation function. Therefore, the high-time-resolution cross-correlation function improves thedistance resolution of the cross-correlation method. In this paper, ultrasonic distance measurementusing cross correlation by single-bit signal processing is evaluated based on computer simulations andthe experimental results.