A Novel Method for Distance and Relative Velocity Measurement in Rear-End Collision Warning System

In the methodology to measure the vehicle-following distance, the general trend is to use a pulsed laser system combined with the high resolution counter to estimate the flight time of laser pulse reflected from the forward vehicle. But in this method, the resolution of distance measurement is limited by the counter resolution.

In this paper, an alternative method to measure distance and relative velocity with fairly high accuracy, which uses the integration of the time delay between transmitted and received pulses and its A/D conversion.

By using this method, we can improve the distance measurement resolution up to a centimeter unit and this satisfies our purpose.