Stability and Safety Analysis of Connected and Automated Vehicle Platoon Considering Dynamic Communication Topology

Connected and automated vehicles (CAVs) can communicate with other CAVs through vehicle-to-vehicle (V2V) communication technology which can improve the stability and safety performance of the platoon. However, the V2V communication could be unreliable as some factors such as hardware damage, packet loss, and cyber-attack, may lead to communication delay or failure. Considering that the communication topology of the platoon can vary dynamically due to these factors, it may result in instability and collision risk on the platoon. To mitigate the impact of communication delay or failure, the study introduces a dynamic weights optimization-based CAV following model (DWOC). It adopts the multi-predecessor following (MPF) mode with which vehicles can obtain the dynamic information of three predecessors and the corresponding information weights can be adjusted adaptively. The study formulates the string stability conditions of the model and validates the stability and safety impact on the platoon through a series of numerical experiments. The results indicate that DWOC can effectively improve the stability and safety performance under different communication delays. The findings suggest that the CAV manufacturers should account for the possible changes of the communication topology of the platoon. The proposed DWOC can serve as a reference in designing the CAV controller to ensure stability and improve safety of the platoon in reality under different communication delays.