Simulation of automated longitudinal control of vehicles in a platoon

A number of simulations has been carried out to study the longitudinal dynamic behaviour of a platoon of eight vehicles. Three vehicle categories have been distinguished, a mid-size passenger car, a van, and a truck. Each vehicle is provided with a sensor to measure the following distance, and with communication equipment to receive data from the lead vehicle and to send data to the following vehicle. This equipment is used in a system which automatically controls speed and following distance ; the driver is no longer involved in the longitudinal driving task. The main simulation scenarios were: encountering a road incline, executing a speed reduction, and entering and leaving the platoon. Two different speed controllers have been compared, namely a fixed PID-controller and a variable PID-controller with speed-dependant parameters. It appeared that the latter performed better. The platoon behaviour was satisfactory, but in order to maintain stability, its length is expected to be limited to approximately 15 vehicles.