Unidirectional Weighted Graph-Based Time-Aware Formation Control for Connected and Automated Vehicle Platoon

The driving safety and formation maintenance of a connected and automated vehicle (CAV) platoon benefit significantly from fast formation regulation. This paper proposes a time-aware formation control (TAFC) strategy to improve the formation regulation time of the CAV platoon. First, to construct an effective information sharing mechanism among the vehicles in the platoon, a unidirectional weighted graph is designed to construct the relation of the CAV platoon and calculate the impact factor between two different vehicles. Second, based on the unidirectional weighted graph, the time-aware requirement is converted into a regulation order problem. The regulation order, which corresponds to the minimum time, is designed and provided with sufficient proof. Third, the qualitative regulation strategy for the CAV platoon is designed and the string stability of the platoon is analyzed with a detailed proof. In addition, the quantitative tune-up strategy of the vehicles is designed. Compared with the existing formation control schemes, the main novelties of the proposed TAFC lie in the regulation orderliness of the CAVs and the target consistency of the CAV platoon are simultaneously considered for achieving the fast formation regulation. In order to analyze the performance of the TAFC strategy, two state-of-the- art methods are selected as the benchmarked methods. The validation results demonstrate that the proposed method possesses better performance in the formation regulation process compared with the benchmarked methods.