Research Of Traffic Congestion Detection And Information Distribution Technology Based On VANET

With the continuous growth of car ownership,traffic congestion problem faced by people is becoming increasingly serious.Vehicular Ad-hoc Networks(VANET)is the hardcore of the future Intelligent Transportation System(ITS),which creatively applies the self-organizing network technology in inter-vehicle communication that provides real-time traffic information for the various types of vehicles on the road,with other communication networks’ irreplaceable advantages.How to use VANET to detect the real-time traffic congestion and distribute the congestion information to the required vehicle group or management institution promptly and efficiently,helping the driving vehicle on the road make the right traffic decision,is of great significance for the effective mitigation of traffic congestion.Combined with the existing researches,this thesis proposes a traffic congestion detection method named CDTC,which is based on workshop cooperation,and includes two parts: vehicle self-congestion detection and workshop cooperation congestion detection.Each vehicle in the VANET would first use various types of vehicle sensors to get its own and road-related data,judging if it is caught in a congested state.After obtaining the judgment of self-status,every vehicle interacted with others around it,selecting a vehicle as the information processing node.The conclusions of the traffic congestion would be drawn according to the relevant data,and the corresponding traffic congestion information would be finally generated.Broadcast communication is one of the most effective methods of information distribution.A distance based multi-hop broadcasting algorithm DIBA is proposed to meet the rapidly and widely distribution of congestion information.In a single hop communication range,the information receiving vehicle which is farthest away from the broadcast vehicle is selected preferentially as a relay node to transmit information.And the timeout mechanism is introduced to ensure the reliability of the information distribution.In addition,in order to ensure the uniform distribution of information,an angle judgment strategy is proposed.According to the vector angle of the broadcast vehicle pointing to the forwarding vehicle and the waiting forwarding vehicle,the vehicle in the waiting forwarding mode is helped to decide whether to continue to participate in the forwarding of information or not.The simulation results showed that the traffic congestion detection method CDTC can meet the requirements for the detection of road traffic congestion.Compared with the other two kinds of classical broadcasting algorithms,DIBA algorithm achieved high information transmission coverage in the case of unique information source nodes,and was well adapted to the distribution of congestion information.