Decentralized control of vehicle platoons with interconnection possessing ring topology

In this paper we design a control strategy for platoons of identical vehicles. It is assumed that each vehicle measures the distance with its immediate forward neighbor. The lead vehicle in the platoon only receives information on the position of the last vehicle in the platoon. We prove that the resulting behavior of the system is a platoon of vehicles moving at a constant velocity with constant distance between each pair of consecutive vehicles and that for a class of identical controllers this solution is asymptotically stable for sufficiently small coupling strength. An upper limit of this coupling strength is calculated, below which the solution is asymptotically stable, independent of the number of vehicles in the platoon. Moreover, simulations indicate that the platoon is string stable. To improve the behavior, integral action is added between the first and last vehicle of the platoon. The resulting behavior is determined and its stability properties are discussed.