Stability and Intervehicle Distance Analysis of Vehicular Platoons: Highlighting the Impact of Bidirectional Communication Topologies

Vehicular platooning, a configuration comprising a leading vehicle and multiple follower vehicles (FVs) seeks to achieve and maintain specific intervehicle distances (IDs) while synchronizing FVs with the velocity and acceleration of the leading vehicle. Before attaining a desired stable state, the IDs may undergo transient fluctuations. While the attainment of internal stability is pivotal for realizing the intended spacing between vehicles, it does not inherently guarantee that these transient fluctuations remain within safe thresholds, thereby mitigating the risk of collisions. Communication between vehicles has a critical role in vehicular platooning and significantly influences these transient distance fluctuations. Consequently, we present a mapping between the initial conditions and these transient fluctuations which hinges on the communication topology (CT), as well as the control parameters. Specifically, our focus is directed toward bidirectional CTs (BDCTs), wherein FVs possess the capability to communicate both with preceding and subsequent vehicles within the platoon. Investigation of these mappings illuminates the advantages and disadvantages of various BDCTs. Notably, we discern that within BDCTs, the receipt of information from a greater number of vehicles situated behind may at times hinder the overall performance of the platoon, resulting in larger deviations from the desired IDs or the velocity and acceleration of the leading vehicle. In contrast, information derived from vehicles located ahead, particularly the leading vehicle itself, serves to enhance IDs and therefore contributes significantly to the safety of the platoon. In conclusion, our theoretical insights are substantiated through a series of simulations.