Research On Key Technology Of Highway Vehicle Rear-end Collision Warning System Based On ZigBee

With the advent of automobile society,traffic safety situation becomes more and more urgent,thus reducing the occurrence of highway traffic accidents is of great significance.Rear-end collision is the most frequently seen form of highway traffic accidents,timely and effective early warning is an important means to prevent the occurrence of it.This thesis proposes a highway rear-end collision warning system based on ZigBee technology.Through the three levels of coordination of car-carried terminal,road nodes and control center,early warning of vehicle risk,early warning of road light,real-time delivery of emergent meteorological conditions and road traffic broadcast can be achieved.This system has great importance to the prevention of auto rear-end collision accidents,the reinforcement of highway traffic monitoring and the optimization of highway traffic scheduling.This thesis analyzes and researches the key technology of the warning system.The major work is listed as follows.1.Overall scheme design.Design each functional module of the system;illustrate the system's operating principle;research factors influencing the exertion of system efficiency;analyze the situation of low proportion of vehicles installing car-carried terminals and the road node failure.2.Warning model design.Propose vehicles' minimum safety distance model which conforms to vehicles' actual working conditions and system early warning requirements based on real-time meteorology and pavement parameters;analyze vehicle risk states and divide the levels and output modes of early warning.3.Locating technology research.Introduce GPS positioning's principles,methods of acquire location information and causing of errors;put forward locating and velocity measuring methods based on ZigBee technology under complicated meteorological conditions;use federated Kalman filtering method to conduct information integration of GPS locating and ZigBee locating data.4.Vehicle-road communication technology research.Choose vehicle-road internode communication program in keeping with the system's requirements;design message format and routing policy;study the anti-interference problems of ZigBee network communication under the highway environment and propose a dynamic anti-interference mechanism based on ZigBee.