Title: Increasing the resolution of laser rangefinders using low frequency pulses

Authors: Sikandar M. Zulqarnain Khan; Giorgio Buttazzo

Addresses: Scuola Superiore Sant'Anna, Via Moruzzi, 1, 56124 Pisa, Italy ' Scuola Superiore Sant'Anna, Via Moruzzi, 1, 56124 Pisa, Italy

Abstract: Laser rangefinders are used in several applications for measuring the distance of a target. Distance is computed by measuring the time of flight of a light pulse to hit the target and come back. The resolution of these devices is strictly related to the precision for measuring time intervals, limited by the oscillator clock frequency of the time-to-digital converter. This paper proposes a novel technique that allows achieving high resolution distance measurements with lower clock frequencies, enabling the development of low cost laser rangefinders. The idea is to increase precision by integrating multiple coarse measurements performed at slightly different clock frequencies, which are properly selected and integrated to produce a time measure with a higher resolution.

Keywords: laser ranging; pulsed time-of-flight; time-to-digital converter; interpolated resolution.

DOI: 10.1504/IJES.2017.083735

International Journal of Embedded Systems, 2017 Vol.9 No.2, pp.157 - 167

Received: 15 Apr 2015
Accepted: 19 Sep 2015

Published online: 21 Apr 2017 *

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