Safe Hierarchical Control of CAVs in Mixed Traffic Scenario: A Level-K Reasoning Based Coalitional Game Approach

This study proposes a hierarchical control of CAVs (Connected and Automated Vehicles) in a mixed traffic scenario. Although there have been many studies using CAVs, there are still few studies on mixed traffic in which a HDV (Human Driven Vehicle) and CAVs coexist. Focusing on the merging control of mixed traffic scenario, many studies have fixed the merging point and merging order, which should be able to be determined freely. To address this problem, we propose a 3-layer hierarchical control method. The upper layer uses a coalitional game based on level-K reasoning. The middle layer uses model predictive control. Finally, the lower layer uses control barrier function. The upper layer decides when to merge in an area by considering the behavior of HDV. The middle layer generates trajectories within constraints. The lower layer uses elliptical constraints to follow trajectories under free merging order safely. Each layer operates at a different time step. Simulation verification of highway merging is performed to demonstrate the effectiveness of the proposed method.