Platooning in the Presence of a Speed Drop: A Generalized Control Model

Abstract

Platooning is expected to enhance the efficiency of operating autonomous vehicles. The positive impacts of platooning on travel time reliability, congestion, emissions, and energy consumption has been shown for homogeneous roadway segments. However, unveiling the full potential of platooning requires stable platoons throughout the transportation system (end-to-end platooning). Speed limit changes frequently throughout the transportation network, due to either safety related considerations (e.g., change in roadway geometry and workzone operations) or congestion management schemes (e.g., speed harmonization systems). These abrupt changes in speed limit can result in shockwave formation and cause travel time unreliability. Therefore, designing a platooning strategy for tracking a reference velocity profile is critical to enabling end-to-end platooning. Accordingly, this study introduces a generalized control model to track a desired velocity profile, while ensuring safety in the platoon of autonomous vehicles. We define appropriate natural error terms and the target curve in the state space of the control system, which is the set of points where all error terms vanish and corresponds to the case when all vehicles move with the desired velocities and in the miniml safe distance between them. In this way we change the tracking velocity profile problem into a state-feedback stabilization problem with respect to the target curve. Under certain mild assumptions on the Lipschitz constant of the speed drop profile, we show that the stabilizing feedback can be obtained via introducing a natural dynamics for