Research On Vehicle Synchronization Following System Based On V2V Communication

With the continuous updating of computer technology,instrumentation technology and communication technology,a greatly development has been taken place in intelligent driving and assisted driving systems in recent years.Many assisted driving systems have been put into practical applications such as lane keeping systems,collision warning systems,parallel line assist systems and adaptive cruise systems.The adaptive cruise system among them has greatly alleviated the fatigue of the driver under long-distance driving and improved driving safety.After the adaptive cruise system is turned on,regardless of how the front speed changes,the vehicle can always travel at the same speed as the preceding vehicle,following the preceding vehicle while maintaining a safe distance.However,the current adaptive cruise system has many shortcomings.The control input mainly depends on the sensor ranging information located at the front of the vehicle.This single information dependence causes the application scenario to be limited to the highway and national road conditions in the driving environment.And because the system response speed is slow,it can not be applied to small-distance follow up,and the following effect of the vehicle is not ideal when the front vehicle speed changes frequently.Aiming at the problems existing in the adaptive cruise system,this paper focuses on the research of the vehicle synchronous following system based on V2V(vehicle-vehicle)communication,considering the difference of different vehicle acceleration and braking performance in the real traffic.The V2 V communication is added to the system to receive power and brake output difference information between vehicles.The two kinds of information are simultaneously used as control inputs of the following system to form a cooperative vehicle longitudinal following control system.The main work of the paper is as follows:(1)Control strategy design and follow-up model establishment of vehicle longitudinal following system.This paper analyzes V2 X communication and V2 V communication technology in the Internet of Vehicles technology.Add V2 V communication system to the following control system based on ranging sensor,According to their respective characteristics,the vehicle following system improves the response speed through V2 V communication,guarantees the control accuracy through the ranging sensor,and further establishes the system following model based on this strategy.(2)The power synchronization process and the distance control method in the vehicle following system.According to the difference of vehicle power and braking performance under real traffic conditions,the power performance and braking performance are classified according to the design rules,and the power and braking grading of the vehicle are synchronized by V2 V communication.Analyze and compare the commonly used vehicle safety spacing calculation method,and improve the spacing calculation method according to the application scenario in the paper.(3)Optimize related problems in the V2 V communication network.Comparing the respective characteristics of the two mainstream V2 V communication standards,the DSRC communication standard with lower information transmission delay is selected to implement the V2 V communication in the vehicle following system.The dynamic prediction link duration model is used to estimate the communication link duration in common road conditions.The traditional V2 V communication forwarding node selection method under long distance is improved to make it more in line with the real-time requirements of information in the vehicle following system.(4)System numerical simulation and miniature model testing.Under the SIMULINK,the numerical simulation of the vehicle synchronous following system based on V2 V communication is carried out under several conditions.The vehicle miniature model with LPC2103 as the system controller and embedded real-time operating system ?C/OS-III as the system software is designed.Vehicle start-up,following,and emergency braking experiments were performed using a vehicle miniature model under a linear test site.The numerical simulation results and actual test results show that compared with the traditional adaptive cruise system,the vehicle synchronous following system based on V2 V communication improves the follow-up response speed of the following vehicle while maintaining the system control accuracy.It also enhances the safety of the vehicle following,allow the vehicle to follow at a smaller distance.It provides conditions for the vehicle following system to be used in more complex road conditions such as urban areas.