Inter-Vehicle Communication Protocol Design for a Yielding Decision at an Unsignalized Intersection and Evaluation of the Protocol Using Radio Control Cars Equipped with Raspberry Pi

Abstract

The Japanese government aims to introduce self-driven vehicles by 2020 to reduce the number of accidents and traffic jams. Various methods have been proposed for traffic control at accident-prone intersections to achieve safe and efficient self-driving. Most of them require roadside units to identify and control vehicles. However, it is difficult to install roadside units at all intersections. This paper proposes an inter-vehicle communication protocol that enables vehicles to transmit their vehicle information and moving direction information to nearby vehicles. Vehicles identify nearby vehicles using images captured by vehicle-mounted cameras. These arrangements make it possible for vehicles to exchange yielding intention at an unsignalized intersection without using a roadside unit. To evaluate the operations of the proposed protocol, we implemented the protocol in Raspberry Pi computers, which were connected to cameras and mounted on radio control cars and conducted experiments. The experiments simulated an unsignalized intersection where both self-driven and human-driven vehicles were present. The vehicle that had sent a yielding request identified the yielding vehicle by recognizing the colour of each radio control car, which was part of the vehicle information, from the image captured by its camera. We measured a series of time needed to complete the yielding sequence and evaluated the validity of yielding decisions.

A Yielding Protocol that Uses Inter-Vehicle Communication to Improve the Traffic of Vehicles on a Low-Priority Road at an Unsignalized Intersection

“…The authors previously proposed a yielding protocol in [8] (hereafter referred to as the "former method") and verified its operation using an experimental system, which consisted of Raspberry Pi computers mounted on radio control cars. However, the former method had problems with the message transmission efficiency and vehicle identification accuracy.…”

“…It is expressed by: No. of vehicles that have started running (8) If a vehicle had not reached its destination by the time the simulation terminated, its speed was calculated by dividing the distance by the time up to the point it reached.…”

“…The authors have previously proposed a yielding method that is applied to an intersection where there is neither a traffic light nor a roadside unit and where a priority level is assigned to each road [8]. It is assumed that both human-driven and self-driven vehicles are equipped with a communication device, sensors, and cameras.…”