A Multi-Vehicle Self-Organized Cooperative Control Strategy for Platoon Formation in Connected Environment

Aiming at the problem of low merging efficiency, poor platoon stability, and high collision risk when multiple connected and automated vehicles merge into the same target platoon, we propose a multi-vehicle self-organized cooperative control strategy for platoon formation, which includes vehicle self-organizing formation control and platoon cooperative merging control. The vehicle self-organizing formation control module organizes the merging vehicles within the V2V communication range into multiple local platoons. The dynamic self-adjusting critical interval and a fixed-topology second-order platoon consistency control protocol are proposed to divided the vehicles reasonably and make the states of local platoon vehicles consistent. The merging vehicles merge into the target platoon as a whole in the form of a local platoon, which transforms the complex multi-vehicle merge problem into a platoon cooperative control problem and improves the merging efficiency. The platoon cooperative merging control module adopts a distributed model predictive control (DMPC) theory to design two longitudinal cooperative merging controllers, which control the target platoon to split to create a merging gap and the local platoon to align with this gap longitudinally. The lateral merging controller controls the local platoon change the lane to merge into the target platoon safely and smoothly. Simulation experiments are conducted in typical scenarios, and it is verified that the proposed control strategy can enable multi-vehicles to merge into a platoon efficiently, safely, and stably.

I. Introduction

The development of Connected and Automated Vehicle (CAV) technology provides a new mode for vehicle driving, namely the platoon-based driving mode. Platooning has attracted much attention due to its advantages of improving traffic efficiency, reducing accident rates, and alleviating traffic congestion [1], [2], [3]. The structure of the platoon is not fixed in the driving process. Flexible platoon expansion needs to respond to the dynamic merging requirements of vehicles. Therefore, in the design of the platoon system, it is an important goal to control vehicles to merge into the platoon efficiently, safely, and stably [4]. The vehicle merging process requires dynamic adjustment between the platoon vehicles and the merging vehicles, and at the same time, the safety and stability of the platoon should be ensured, which puts forward strict requirements for the longitudinal control of vehicles merging into a platoon [5]. When multiple vehicles merge into the same platoon, the problem becomes more complicated.