Various types of warning and vehicle-control systems using inter-vehicle distance, such as Forward Vehicle Collision Warning System, Side-Rear Obstacle Warning System, and Adaptive Cruise Control, are proposed on the ITS activities. To realize these systems and to obtain wide utilization, sensors for inter-vehicle distance measurement are indispensable. To this end, a prototype sensor for the distance measurement on the basis of stereo-images has been developed. It features small size (H61.5mmxV69.9mmxW46.9mm), consisting of an optical system which includes multi-line CCD and lens, a customized integrated circuit (IC) for correlation of stereo-images and interpolation to obtain highly accurate data, and a general use central processing unit (CPU) for vehicle detection and CCD control. The distance to a detected vehicle in front can be obtained by the operation of the multi-data of distance (16x46) in the field view (H12.2 deg x V9.2 deg). The test results show that the distance can be measured up to about 40m on a highway including a curve with its curve radius of 400m. This paper shows the features of the prototype sensor, the algorithm for detecting a vehicle in front, and the test results. (A*)
Abstract