Visible light phase-shift rangefinder for platooning applications

Vehicle positioning and environment awareness are key components in new intelligent transportation systems (ITS) which explains the growing demand in distance sensors. Though several efficient technologies already exist, the growing automation of vehicle requires sensors redundancy. In this paper, we introduce a new, simple and low cost distance measurement scheme using the headlamps and taillights of the vehicles. The following vehicle (FV) emits a periodic signal toward the leading vehicle (LV) which receives, processes and re-emits it. The FV then exploits the phase-shift introduced by this round trip to recover the distance. A complete simulation model is built and tested. This study shows that our system is able to measure distances up to 25 meters with a resolution under 10 centimeters, and up to 30 meters with a 30 centimeters resolution, at a refresh rate of 267 Hz. Even if the regulated optical power and beam limits the range of such a system, it is particularly suited for platooning applications where vehicles are close.