A Cooperative Strategy For Lane Change Maneuver Between Platoons

The self-driving vehicle platoon is an essential part of the intelligent highway system and is one of the rising fields nowadays.In particular,research on the cooperative lane change control between different platoons is of great significance of improving driving safety and traffic efficiency.However,most of the existing researches on platoon focus on the string stability control,and lacks studies on platoon splitting,merging,rearranging and lane-changing strategies.Aiming at these topics,this thesis takes two vehicle platoons running on the highway as the research object,and studies the cooperative lane-changing control between different platoons based on the vehicle-to-vehicle communication technology.Firstly,the overall control architecture of the cooperative lane-changing between different platoons are proposed based on the classification of vehicle lane-changing scenarios.According to the number of vehicles and scenes involved in the lane change,the scenarios are divided into four categories: free vehicle entering the existing platoon,single vehicle lane-changing between two platoons,multiple vehicles lane-changing between two platoons,and platoons merging.For the four types of scenarios,a general hierarchical control architecture is proposed,including a communication layer,a decision layer and a control layer.The communication layer contains the information transmitted between different vehicles,topology of the communication network and the information transmission process between different layers in consideration of delay and packet loss.Secondly,in the decision layer of the cooperative lane-changing,an algorithm computing the optimal insertion position for the lane-changing vehicle and an IDupdating strategy are proposed.The main body of the cooperative lane-changing decision layer is the leading vehicle of each platoon.The decision layer is mainly responsible for ID monitoring and updating of all the vehicles in the platoon.In order to determine the optimal entering position for the lane-changing vehicle in all the scenarios,two algorithms based on traversal and fuzzy logic are respectively proposed.On this basis,the ID of each vehicle in the platoon is determined,and then vehicle ID updating are performed on the entire platoon.Thus,the platoon is managed effectively.In the cooperative lane-changing control layer,a longitudinal and lateral motion decoupling control method was proposed.The main body of the cooperative lanechanging control layer is the individual vehicle in the platoon,which is responsible for control its longitudinal and lateral motion.In order to stabilize the running of vehicle platoons under different topologies of the communication network,a distributed longitudinal motion control strategy is designed,including the strategy of running longitudinally in the platoon and the strategy of lane-changing.In order to ensure the stability of lane-changing under different driving speeds and the accurate tracking of the lane-changing trajectory,a lateral motion control strategy is designed,including the design of a fifth-order polynomial-based lane-changing trajectory and the PID tracking controller.Finally,in order to verify the effectiveness of the proposed cooperative lanechanging control strategy,a simulation platform based on MATLAB/Simulink and Prescan is built.The simulation results indicate that the cooperative lane-changing control strategy between different platoons ensures vehicles safely and efficiently entering and leaving the platoon,and keeps the stability of the original platoon with minimum speed fluctuation.In the meanwhile,the control strategy can also work with some network delay.