Latency Analysis for Inter-Vehicle Communications 2006-01-1330

The study done by the U.S. National Highway Traffic Safety Administration (NHTSA) shows that developing automotive collision warning and avoidance systems will be very effective in order to significantly reduce fatalities, injuries and associated costs. In order to develop an automotive collision warning and avoidance system, it will be necessary that the vehicles should be able to exchange (in real-time) their dynamic information such as speed, acceleration, direction, relative position, status of some devices like brake, steering wheel, gas pedal, etc. The only feasible way to exchange the vehicles’ dynamic information will be through the use of wireless communication technology. However, the wireless link setup time and communication latencies should be under certain bounds so that the vehicles can appropriately react on time to avoid collisions. This paper will present results from an experimental setup that simulates inter-vehicle communications.

The experimental setup has been prepared using a number of CAN and Bluetooth modules. The communication system of each vehicle has been simulated using several CAN nodes and a wireless module. In addition, a number of stand-alone Bluetooth modules have been used in the experiment to increase the wireless communication traffic through the air. An event such as pressing the brake pedal or turning on the turn signals has been simulated using buttons. At the occurrence of an event, the simulated vehicle system automatically sends a message through its CAN bus, then it broadcasts the message via its wireless module. Other simulated vehicles receive the message via their wireless modules and then send the message via their CAN buses. Eventually the message triggers some actuators in the destination vehicles. The latencies have been measured from the time an event occurred and until the time some actions have been taken by the actuators of the destination vehicles.

The paper presents results on inter-vehicle communication latencies under various types of traffic conditions. Other researchers and engineers will get valuable information from this paper which will help them in designing wireless communication systems for the future vehicles.