Research On Vehicle Flow Situation Awareness Method And Its Model

With the acceleration of urbanization and the improvement of material living standards,car ownership has increased rapidly.Cars can bring convenience to people's travel,but also can increase the traffic pressure of the city,resulting in the continuous deterioration of traffic conditions,causing serious losses to the national economy.In order to solve this common global problem,domestic and overseas traffic scholars have studied the effective methods of using advanced technology to eradicate urban traffic congestion in order to adapt to the rapid development of current social economy for a long time,but have not achieved satisfactory results.On the basis of previous studies,the characteristics of traffic flow on urban expressway are systematically analyzed in this paper,a model of acceleration fluctuation is established,and the fluctuation characteristics of acceleration are obtained,it provides theoretical basis and methodological basis for traffic system evaluation and optimization.Through the establishment of situation awareness model of traffic flow,real-time identification of traffic flow operation status can be realized.Through the application of vehicle-road collaboration technology,information transmission between vehicles and roads can be realized,thus changing traffic flow operation status and improving traffic operation efficiency.In the first part,the operation characteristics of traffic flow are analyzed from both micro and macro aspects.In the micro aspect,the two behavior characteristics of car-following and lane-changing are analyzed;in the macro aspect,the traffic flow is divided into three operation states: free flow,synchronous flow and congestion flow,and the characteristics of traffic flow are analyzed;and also the types and classification criteria of conventional traffic congestion.The second part establishes the situational awareness model of vehicle flow operation under the vehicle-road collaboration environment.This paper introduces the connotation of situational awareness and situational awareness model,mainly through the real-time monitoring and perception of the traffic flow situation,to get the current road operation status,and through the vehicle-road cooperation technology,to release the traffic status to the surrounding vehicles in real time,so that the vehicles can make intelligent processing in time,so as to improve the traffic flow operation efficiency.The third part puts forward that the internal cause of the development and change of the traffic flow situation is to study the law of the change of the traffic flow acceleration.Therefore,the acceleration of urban expressway is analyzed by mathematical statistics,and the trend of acceleration is obtained by drawing the curve of acceleration data.The acceleration mathematical model is established.The validity of the acceleration model is verified by sampling the acceleration data of traffic flow under different density conditions.Finally,two wave patterns of acceleration are established.In the fourth part,through the application of traffic congestion classification based on traffic situation awareness model and Vehicle-to-Infrastructure cooperation technology,intelligent signal generator can generate signal schemes adaptively according to traffic congestion classification and actual congestion conditions,thus alleviating traffic congestion and reducing further expansion of traffic congestion.Then,through the establishment of simulation experiments,the validity of the model application is verified by comparing the original scheme with the adaptive control scheme through the signal control scheme of multiple intersections on the experimental road.