PLATOON SYSTEM BASED ON OPTICAL INTER-VEHICLE COMMUNICATION

This paper deals with the techniques for inter-vehicle communication and gap distance measurement, both of which are very important for the gap distance control of the platoon system. As an inter-vehicle communication system, an optical space communication system was developed using an IR-LED and an IR sensor for securing one-to-one communication scheme. To prevent interferences within a platoon of vehicles, the transmission timing of each vehicle is controlled by an on-board computer. For controlling the gap distance accurately, a revolutionary gap distance measuring system was developed. This system is configured of a CCD camera and optical markers, which double as a transmitter for the communication system. Markers in the image are detected by an image processing computer. The gap distance is calculated from the parallax error between two markers. To avoid disturbances due to the reflection of sunlight or the like, the image-pickup timing of the CCD camera is synchronized with the blinking of the markers. The measurement error was 1 percent for the gap distance of 1 to 10 m. A confirmation test was conducted on a test truck using an experimental vehicle having an inter-vehicle communication system. A platoon driving with gap distance of 10 m at the vehicles' speed of 100 km/h was successfully conducted.