May I enter the roundabout? A time-to-contact computation based on stereo-vision

This paper presents a stereo-vision based system for the recognition of dangerous situations at roundabouts. At first, we investigate the necessary field of view and viewing direction using videos taken by a panoramic camera. Using the insights of these tests we build up a stereo-vision system. This system is based on the well established disparity estimation scheme Semi-Global Matching and the recently introduced medium-level representation called Dynamic Stixel-World. A time-to-contact measure is defined that makes explicit use of the roundabouts structural characteristics. Using this measure enables us to create a system for driver warning or possible automated intervention. Our empirical studies reveal that the warning decision correctly mimics human driver decisions.