Research On Vehicle Platoon Control In Automated Highway System

The automobile industry is developing with the three eternal themes of safety,environmental protection and energy conservation.With the application of many new technologies to automobiles,the modern automobile is gradually becoming intelligent,networked and electric.At the same time,various traffic problems are becoming more and more prominent,so the idea of using all kinds of advanced technology to solve the traffic problem is proposed at the moment.This paper studies the platoon method to solve the existing traffic problems by using the vehicle platoon control in the automated highway system.Combined with the "magic formula" tire model,a seven-degree-of-freedom vehicle model is established as the vehicle motion state solver for the platoon control.Based on the vehicle spacing error,the vehicle longitudinal platoon model is established.And the vehicle longitudinal car-following sliding mode controller is designed by using the bidirectional-leader following and predecessor-leader following method.According to the vehicle lateral path-preview method,the lane-keeping sliding mode controller is designed.Using trigonometric method,the lane-changing trajectory is planned.And the lane-changing sliding mode controller is designed.The stability of sliding mode controller is verified by Lyapunov stability analysis.By establishing MATLAB/Simulink simulation model,the feasibility of the sliding mode control method is verified.According to the working principle of the automated highway system,this paper puts forward the platoon control steps about the vehicle joining or leaving a platoon and platoon merging or splitting.In view of two basic vehicle platoon movements about the vehicle driving in a platoon and the whole platoon changes lane,the coupling controller about longitudinal car-following and lane-keeping,longitudinal car-following and lanechanging is designed.Through the MATLAB/Simulink simulation,it is proved that the coupling controller of longitudinal car-following and lane-keeping can keep the vehicle moving in the center line of the lane,in the meanwhile the expected distance between vehicles in the platoon is maintained;and the coupling controller of longitudinal carfollowing and lane-changing can enable the vehicle in the platoon to follow the speed of the leader vehicle and change the lane according to the scheduled change track.The coupling controller of vehicle platoon is designed according to car-following,lane-keeping and lane-change the three basic longitudinal and lateral control method.In three different situations,the safe lane-changing distance is put forward.Using the vehicle model in CarSim as the vehicle status solver in the platoon,the simulation model of the vehicle joining or leaving a platoon and platoon merging or splitting is set up in MATLAB/Simulink.Through the joint simulation with CarSim,it is verified that the designed vehicle platoon coupling controller can enable the vehicle to complete the complex platoon movement.