Unsignalized intersection vehicle platoon formation scheduling method based on mixed traffic.

Managing unsignalized intersections is further developed in the context of automated driving with vehicle-road coordination. In this context, the virtual platoon of lining vehicles into a one-dimensional virtual queue is based on a fully automated driving environment. It cannot be used in today's mixed traffic, and improper sequencing rules can cause significant delays. Thus, we propose a hierarchical framework to manage unsignalized intersections, where the lower-level distributed controller controls the mixed vehicles to form a vehicle platoon with CAV at the head of the platoon. The upper-level collaborative controller determines the passing order of the vehicle platoon. In deciding the passing order, we propose the Mixed Platoon Scheduling Model (MPSM) to improve the traffic safety and efficiency of unsignalized intersections in mixed traffic environments and to obtain the optimal vehicle passing order without collisions. First, MPSM transforms the conflict scheduling optimization problem into a graphical optimization problem to get a Mixed conflict-directed graph (MCDG) of nodes. Second, the spanning tree's depth and average width are optimized by coexisting undirected graphs so that the number of vehicle platoons passing through the intersection simultaneously increases. Then, we change the order of the spanning tree nodes to reduce potential delay. The effectiveness of the intersection management framework was evaluated experimentally. The results show that MPSM possesses good delay performance and has an advantage over Adaptive Signal Control Method (Adaptive-SIM), FCFS, and DFST algorithms, which can be applied in different traffic environments.