ROAD-VEHICLE COMMUNICATION SYSTEM, DISTANCE RECOGNITION METHOD, AND OPTICAL BEACON AND ON-VEHICLE UNIT USED FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a road-vehicle communication system, a distance recognition method, and an optical beacon and an on-vehicle unit used for the same, computing a distance to a predetermined position in front of a vehicle with high accuracy. SOLUTION: The road-vehicle communication system comprises the optical beacon 4 and the vehicle side on-vehicle unit 2 carrying out bidirectional communication with each other by optical signals, and a vehicle sensor 5 for sensing the vehicle. The optical beacon 4 comprises elapsed time information acquiring part 7b acquiring elapsed time information on the time elapsed from receiving a vehicle sensing signal s from the vehicle sensor 5, and a control part 7a storing the elapsed time information and distance information on a distance from a sensing area K to a predetermined downstream position in second down-link information 36 and transmitting the information. The on-vehicle unit 2 comprises an arithmetic part 26a acquiring a distance to the predetermined position from a present position where each information is received, based on the elapsed time information and the distance information. COPYRIGHT: (C)2008,JPO&INPIT