Abstract
Rear-end collision accidents often occur in the rush hours because a safe headway is difficult to be sustained by the drivers in a heavy traffic flow. Due to the accumulation of the response-delay of drivers, a hard brake of the leading vehicle may cause rear-end collisions for the following vehicles. One of the active solutions for rear-end collisions is to eliminate the response-delay of drivers by inter-vehicular communications. Based on the infrared dedicated short-range communication (IR-DSRC) technology and the vehicle-to-vehicle (V2V) architecture, this study proposes a cooperative vehicular rear-end collision warning (RECW) system to avoid a rear-end collision. A single-lane experiment of three-vehicle system is set up to validate the analysis of the cooperative rear-end collision warning system and to demonstrate its feasibility in the field test. The results of experiments show that the proposed system effectively eliminates the response-delay of the second driver, while extending the time margin for a possible hard-brake warning to the third driver by sending out a clear hard-brake warning message, even before the second vehicle applies its brake. To locate a vehicle producing false alarms on the neighbor lane, this study proposes a novel 3D IR positioning system to locate the vehicle by its emitted IR signals, which is demonstrated by a two-vehicle field trial. Furthermore, a lane-recognition method based on the 3D IR positioning system is developed. Once a vehicle emitting an RECW alarm signal, the nearby vehicles can identify its lane-identity and only the alarms from vehicles on the same lane are propagated backwards. The experiments for lane-recognition are conducted to validate the proposed approach.