Abstract
In this paper, a new method to detect the trace of a vehicle's movement by using four optical line detectors and fourth order crosscorrelation analysis is proposed.
In this method, during the movement of the vehicle, the line detectors observe the relatively moving road as the intensity variation of the light reflected from the road on the line of each detector. On the first line detector, however, properly separated two windows are provided so that it detects only the flow of the road pattern passing through these two windows. Then the time delays of such pattern flows between the first detector and the others are estimated by using the fourth-order crosscorrelation analysis of the detected signals, and the parameters about the relative movement of the road pattern, say, the velocity and the radius of curvature are derived by combining the estimated delays and the geometry of the detectors' arrangement.
These parameters identify the instantaneous trace of the vehicle as the approximated circular arc, hence, the desired trace of the vehicle can be reconstructed by connecting sequentially these instantaneous traces.
To confirm the validity of this method, an actual measurement system was constructed and preliminary experiments were carried out by moving the photographs of the real road as the model of moving rough surfaces. The results showed clearly the usefulness of the proposed system.
