Research On The Key Technologies Of V2X System For The Application Scenario Of Connected Automated Vehicle Warning

V2X(Vehicle to X)vehicle terminal is the core hub of the car’s interaction between the vehicle and the outside world.Through V2 X,you can not only receive messages from other vehicles equipped with V2 X terminal,but also get the broadcast road condition information of traffic lights,variable information boards and other signals in advance.The warning application with V2 X gets the corresponding warning judgment by the processing and calculation of this information,and then corrects in the driving mode of the vehicle.Therefore,how to design V2 X terminal hardware system and develop standard V2 X warning scenario algorithm have extremely vital significance.Through the research on the development of vehicular communication system of cooperative intelligent transportation system,it is known that the current application in V2 X terminal is based on DSRC(Dedicated Short Range Communications)communication technology,and the function of the designed warning application scenario is too uncomplicated.Therefore,in this paper,after collecting a large number of technical information and studying the argument in detail,based on LTE-V2X(Long Term EvolutionV2X)communication technology,the V2 X terminal and its warning application for intelligent driving and cooperative vehicle infrastructure have been developed.Because the research on LTE-V2 X communication terminal is still in initial stage,the V2 X terminal equipment and warning application designed in this paper has good foresight and innovation.The test system designed and built can fill the blank in V2 X test and provide a reference solution for subsequent test research.The main research contents and achievements are as follows:(1)For the application of V2 X terminal in vehicle,this paper analyzes and summarizes the performance indexes,functional requirements and the design and development of functional interface reservations of V2 X terminal,designs the overall diagram of hardware system of the equipment,and completes the design of four major functional modules: radio communication subsystem,data processing unit,GNSS positioning system and antenna system.(2)Four application scenarios are designed and developed: forward collision warning,intersection collision warning,ahead road construction warning and speed guidance.In the warning model designed in this paper,the false alarm rate is very low by adding map matching algorithm and vehicle orientation judgment.At the same time,driver’s response time and vehicle deceleration are added to the warning model to calculate,and more appropriate braking distance is reserved for the driver.(3)After completing the design and manufacture of the terminal system,according to the test content and items specified in the 3GPP standard,the performance test system was designed and basic performance tests were performed to verify the RF characteristic and communication performance of the designed equipment in this paper,which basically meet the standard requirements.At the same time,according to the standards in GB/T31024,virtual test scene and real vehicle road test scene are built to verify the warning application function of V2 X.Combined with virtual scene test results and real vehicle test results,it shows that V2 X terminal can send warning information timely and reliably,the V2 X terminal warning application of intelligent driving and cooperative vehicle infrastructure designed in this paper is feasible.