Research And Implementation For The Forward Collision Warning System Based On DSRC And DGPS

FCWS can effectively avoid or reduce forward-collision-accidents.The key is to sense the traffic surroundings timely and effectively first;and then,with the accurate FCW model,to detect and assess collision threat;finally,to alert the driver at the right time.In addition,in order to improve the accuracy,false alarms and missing alarms need to be as less as possible.Traditional collision warning system generally adopt close-detection like microwave,camera,lidar,radar,and the like.But such methods can not detect those vehicles around which are far from the host vehicle or non-line-of-sight,and can not obtain the information of numerous vehicles or environment simultaneously,and are seriously influenced by bad weather.Compared to them,DSRC(Dedicated Short Range Communication),for use in vehicle-to-vehicle and vehicle-to-roadside communication,has longer communication range than other methods,and is free from weather or line of sight influence.DSRC works on dedicated frequency bands,so that it does not need to compete for channel resources with other applications except for vehicular applications,leading to more effective communication.The forward collision warning system,based on dedicated short range communication and differential global positioning system,is realized by information acquisition,DSRC communication,collision warning algorithm,and alert.The system acquires the host vehicle's identification information and running status through vehicle sensors,GPS receiver,CAN bus and so on.And then,vehicles and roadside equipment exchange their identification information and running status to learn the environment condition like road and vehicles.Collision avoidance algorithm calculates and judge if there is risk of collision and decides the level of the risk,and give an alert to the driver at a right time beforehand.Thus the driver take collision avoidance control and improve the road safety.This system gets the assistance of differential global positioning system to obtain high accuracy position signal.The research makes use of the V-X testing place and hardware facility of a certain automotive engineering research institute to construct a hardware platform of V-X;and designs collision warning algorithm under different testing scenarios like leading vehicle is stationary,slow-moving,and braking to decelerate;and develops a V-V forward collision warning system and carries out real vehicle test and makes analysis,to validate the validity of the system.The main research contents as follows:(1)A collaborative forward collision warning system based on DSRC and DGPS is designed.In the system,a collision warning model is deduced,and its MATLAB Simulation model validation under three FCW scenarios is conducted.First,the overall design of the forward collision warning system based on DSRC is conducted,including vehicle-mounted terminal,roadside equipment RSU,communication lines,and positioning system.Second,car-following models under line of sight and non-line of sight are built.Third,research on vehicle detection methods and V-X communication based on DSRC is conducted.Finally,distance detection model is established,and safety distance calculation model under different scenarios like leading vehicle is stationary,slow-moving,braking to decelerate is set up,including the model parameter determination and critical warning threshold determination,correspondingly.In addition,the model is simulated and validated by MATLAB.(2)A hardware platform of the collaborative forward collision warning system based on DSRC and DGPS is constructed.The hardware platform includes vehicle-mounted DSRC terminal,vehicles,roadside controller,roadside communication devices,logical and physical network.And there are four classes: sensing unit like CAN bus,positioning model;communication unit like DSRC vehicle-mounted terminal and RSU;storage unit like database;alarming unit.(3)A software platform of the collaborative forward collision warning system based on DSRC and DGPS is developed.The software platform includes connection and receive module,frame parsing module,data storage module,collision warning algorithm module,front-end module.The tasks of the software platform work from prototype design for the system's interface using.NET Winform;and secondly,programme using C# to register with DSRC device to develop a UDP connection and receive information frame from the DSRC device endlessly,and programme to parse the information frame and get traffic participants' information and store them;thirdly,create a MYSQL database to store the parsed data;finally,programme to realize the forward collision warning algorithm model with the parsed data and realize the emergency alarm at different levels.(4)In the end,real vehicle tests of the system under different scenarios are conducted.The test result shows that the system can effectively work and can realize V-V communication and collaborative forward collision warning.