Model Checking Longitudinal Control in Vehicle Platoon Systems

With a steadily growing number of vehicles, our roads are getting more and more crowded. As a consequence, traffic jams are becoming common. Vehicle platoon systems form a possible solution in the short term. It consists of a number of vehicles automatically following a leader vehicle, in-line, one after another at a short but safe distance. Ideally, all vehicles have to maintain the same speed, so as to have a better usage of the road by minimizing the distance between two vehicles. In this paper we present a timed automata model of a vehicle platoon system with the goal of finding a minimal but guaranteed safe distance between two vehicles under variable speed. Contrary to other models based on cooperative adaptive cruise control, we assume no (Internet) communication among different vehicles or road system. Instead of such global perspective we rather take a local point of view: each vehicle relies on its own sensors to dynamically calculate and maintain a safe distance with the preceding member of the platoon. We use the model checker UPPAAL to verify that the system does not deadlock, and most importantly, that it is safe, avoiding crashes at all time.