Control of platoons of heavy-duty vehicles using a delay-based spacing policy

The formation of groups of heavy-duty vehicles driving at close inter-vehicular distances (known as a platoon) reduces the fuel consumption due to a decreased aerodynamic drag and has the potential to increase traffic flow. This paper motivates the use of a novel spacing policy, which specifies the desired distance between vehicles as a function of their states. Particularly, a delay-based spacing policy is introduced, which guarantees that all vehicles in the group follow the same velocity profile in space. It is shown that the proposed spacing policy offers advantages in the platoon control for non-constant reference velocities, which are common when driving over hilly terrain. A controller is designed to achieve this spacing policy, hereby exploiting an analysis of the vehicle dynamics in the spatial domain rather than time domain. Moreover, the controller is shown to attenuate the effect of disturbances as they propagate through the platoon. Simulations are used to illustrate the effectiveness of the proposed spacing policy and controller.