| 摘要 |
PROBLEM TO BE SOLVED: To improve the reliability of optical beacon communication and to make the light emitting element of an optical signal have a long life by optimizing the timing interval repeatingly transmitting up link data after an optical beacon on-vehicle device detects the signal from a road machine. SOLUTION: An optical beacon on-vehicle device is connected with an optical beacon on-vehicle device light projecting and receiving part 2 composed of a light emitting part 7 and light receiving part 8, the encoder 6 of transmitted data, the decoder 5 of received data and a vehicle speed detector 3, and performs the input/output of the optical signal for which a data modulation is performed and the fetching of a vehicle speed signal. When up link data is received when the signal transmitted from this optical beacon on-vehicle device is from a receivable area, a road machine transmits a response signal based on a reception signal. In this case, this on-vehicle device detects the running speed information of the vehicle by a vehicle detector 3 and controls the repeating transmission interval of up link data so as to shorten the interval when the speed is fast and to lengthen the interval when the interval is slow. |
