In the work herein and in [1], an automatic control concept is developed for both normal and emergency longitudinal regulation of high density strings of vehicles with velocities in the range 50 to 90 mph (80 to 144 km/hr). Under this concept, a vehicle string is formed into platoons of vehicles, the lead vehicles of which are governed by wayside-mounted controllers. Excluding platoon leaders, vehicles are controlled by on-board controllers, termed car-following or following-law controllers, which continuously regulate vehicle spacing and velocity with respect to the preceding vehicle, and velocity with respect to an external, desired velocity. Wayside controllers, which communicate with vehicles only when they cross discrete control points along the guideway, provide “modified block control” of lead vehicles, maintaining a safe stopping distance such that collisions under an instantaneous stop cannot occur between vehicles of separate platoons. The proposed control appears suitable for realistic guideway conditions and provides flexibility in performance tradeoffs among wayside hardware, safety, nominal guideway line speed, and guideway vehicle capacity. Spaces generated between platoons under normal operation afford capability for merging from off-line queues.
The cooperative sorting strategy for connected and automated vehicle platoons
