Study And Experiment Of Longitudinal Platoon Control For Connected Vehicles Based On Variable Time Headway Policy

Multi-vehicle platoon has been widely concerned by the industry and academia because of its advantages of safety,energy-saving,and high efficiency.As a key part of platoon control,the impact of spacing policy on the performance of vehicle platoon control can not be ignored.In practical applications,in order to improve the safety and efficiency of vehicle platoon,the spacing between vehicles needs to be dynamically adjusted to optimize the mobility and flexibility of the platoon.In view of this,this thesis will start from the actual driving needs of the vehicle platoon,and firstly adopt a more practical and effective variable time headway spacing policy.Then,based on the variable time headway spacing policy,the corresponding vehicle platoon control algorithms are designed considering the external time-varying disturbances and heterogeneous communication delays respectively,which can ensure the stable driving of the vehicle platoon.Finally,a connected micro-vehicle experimental platform is built to testify the validity of the developed platoon control algorithms.The contents of this thesis mainly include the following three aspects:1.For the problem of vehicle platoon control under the influence of spacing policy and external disturbances,a variable time headway policy based longitudinal platoon controller is proposed by considering external disturbances.Firstly,based on the more effective variable time headway policy,considering the influence of external disturbances,the vehicle platoon control algorithm is designed combined with the consistency theory and the sliding mode theory.Furthermore,the stability of the developed control algorithm is demonstrated by utilizing the RouthHurwitz criterion and Lyapunov theorem.Finally,the effectiveness of the proposed control algorithm is verified by numerical simulation.2.For the problem of vehicle platoon control under the influence of spacing policy,external disturbances and communication delays,a variable time headway policy based anti-disturbance longitudinal platoon controller is proposed by considering heterogeneous communication delays.In the process of data transmission,vehicle platoon control is inevitably affected by random communication delays due to channel congestion and bandwidth limitations.Based on research content one,the influence of heterogeneous delays is further considered.Using consistency theory and high-order integral sliding mode theory,a variable time headway policy based anti-disturbance control algorithm for vehicle platoon under the delay environment is designed.And the stability of the developed control algorithm is testified by utilizing Lyapunov and its derivative theorem.Finally,the validity of the developed control algorithm is tested by numerical simulation.3.The experimental platform of the connected micro vehicles is built to testify the practical feasibility of the developed vehicle platoon control algorithms.The micro vehicle experimental platform is mainly composed of two parts: the hardware system and the software system of the micro vehicle.The hardware system takes STM32 microcomputer as the core controller,combined with other sensors and WiFi communication modules to realize vehicle data collection and transmission.The software system includes creating a local area network server and database to realize the function of data forwarding and storage,and then forming a complete micro vehicle experimental platform through joint debugging of software and hardware.Finally,the proposed control algorithm is loaded into STM32 microcomputer in programmed language,and a platoon consisting of three micro vehicles experiment was conducted to illustrate the validity of the developed platoon control algorithms.