Precise position and speed detection from slit camera image of road surface marks

We propose a scheme to detect precise position and speed by an image processing technique. As an input device we use a slit camera mounted in front of a vehicle looking downwards. The slit is aligned to the lateral direction, and the space axis and the time axis of the resulting image correspond to lateral and longitudinal direction. The longitudinal length of the resulting surface image varies according to the vehicle speed and gives speed information. The position to be detected is assumed to be at the center of each lane and four separate white bars are aligned in a diagonal position symmetrically to the assumed center. We detect these white bars in the resulting image and approximated by two lines. The crossing point of these two lines gives the assumed center in the image. We showed the effectiveness of this scheme by test course experiments using a passenger vehicle. We also showed that information related to the position can be coded as bar codes on the road surface and our camera configuration is able to detect these bar codes.