Research On Longitudinal Cooperative Following System Of Intelligent Vehicle Platoon Based On V2X Communication

With the rapid development of intelligent driving technology,people put forward higher requirements for the efficient and safe transportation.As an important research content in the intelligent traffic system,driving of vehicle platoon has great significance for improving traffic efficiency and ensuring the traveling security.The application of V2 X technology can make the vehicle interact with each other,thus provides a new way of collaborative control of vehicle platoon.In this paper,the V2 X is introduced into the control of vehicle platoon,and a longitudinal collaborative following system is researched and designed for the intelligent vehicle.The main research contents are as follows:First,the hardware and software architecture of the collaborative following system are built.The hardware architecture is designed,which takes the Lidar as the sensing device,the high-performance Industrial Personal Computer as the decision-making unit,and the Wirecontrolled vehicles as the actuator,based on obtaining the status information of the vehicle ahead by using V2 X equipment.Then,the distributed node software architecture is designed based on ROS,which integrates perception,communication,decision and execution of intelligent vehicle.The system is divided into data acquisition module,data communication modules,collaborative decision module and motion control module.The modules communicate with each other in the form of topic.Next,the model of the collaborative following system is established.Under the condition of driving and braking,the longitudinal dynamic models are built by using the principle of inverse longitudinal dynamics of vehicle.The longitudinal controller of vehicle platoon is designed to be hierarchical control structure.In the upper controller,the expected acceleration is calculated through the cooperative following algorithm.In the lower controller,drive-bywire and brake-by-wire system are used to control the vehicle.The spacing control strategy and information flow topology of vehicle platoon are determined,which was used to build state space model of platoon.Then,a cooperative following control algorithm under V2 X communication delay is designed.By analyzing the communication delay generated in the process of acquiring the state of the vehicle ahead by using V2 X,a front vehicle status update algorithm based on the Kalman filter principle is designed.The speed error and distance error generated during the following process is calculated and updated by predicting the real value of the previous vehicle state.According to the result of following error,the cooperative following control algorithm based on MPC and adaptive fuzzy PID principle is designed respectively.The simulation model of the system is established by CARSIM/SIMULINK joint simulation platform,and the two algorithms are compared and analyzed under different driving conditions.The simulation results show that both control strategies can keep the system with good following performance,and the system has less following error with MPC control,but better following comfort with fuzzy PID control.Finally,the real vehicle verification of the system is completed.The fuzzy PID is selected as the upper control strategy of the real vehicle for the experiment,and the results show that the main functional modules of the system can work stably,and the cooperative following system based on V2 X designed in this paper has certain degree of accuracy and can basically realize the longitudinal following function of intelligent vehicle.