A Study on Variance Reduction in Measuring Headway Distance by Using the Stereo Disparity and the Image Height of Target Vehicle

Abstract

This paper describes a method to reduce a variance of measured headway distance using stereo vision. In this method, first, headway distances are measured by both the stereo disparity and the difference of the size of a preceding vehicle on image, and then one of them which has smaller variance is chosen as the headway distance. The size of a preceding vehicle on image is measured by a new method of detecting the edges on the preceding vehicle which alleviates the bad influence of change in back ground. A headway distance measuring system using this method has been developed, showing the effectiveness on tracking a preceding vehicle within 25m headway distance.