Cooperative Traffic Model Of Vehicles On Highways Accident Section Under Intelligent Network Connection

With the development of economy and society,the rapidly developing modern transportation not only provides convenience to mankind,but also causes problems such as energy shortage,environmental pollution,traffic congestion and frequent traffic accidents.With the emergence and development of technologies such as communication and automated control,the Connected Automated Vehicle(CAV)under the condition of intelligent connection has become an effective solution to those problems.Since the vehicles are fast and traffic volume is larger on highway,after a traffic accident occurs in highway,it is more likely to occur subsequent accidents or even continuous rear-end collisions,exacerbating losses.In the meantime,the structure of the highway is relatively simple,which makes highway the main application scenario of CAV technology.Therefore,based on the CAV technology,how to perform coordinated traffic control of vehicles on highway after an accident to ensure the smoothness of the road and the stability of the traffic flow has become a hot spot in the research of CAV technology.To solve the problem,this article proposed a complete collaborative control model in the highway accident scene.The simulation are performed to prove the effectiveness of the promoted model.The main research contents are as follows:(1)In terms of vehicle lane-changing rules,this paper proposes a lane-changing model based on the characteristics of the fleet and vehicle speed.This paper analyzes the environmental structural characteristics and vehicle motion behaviors in the highway accident section,and construct a complete highway accident section scene.It proposes the assumptions based on the CAV technology,and a vehicle type classification method based on car-following characteristics and vehicle speed characteristics.Considering the kinematics model and vehicle type,different lane-changing head spacing constraints are proposed,and a solution control method based on the ergodic method is proposed to solve the longitudinal acceleration.The model controls the movement of multiple vehicles related to lane-changing.The coordination is applied.(2)In terms of vehicle lane-changing motion control,this paper proposes a lane-changing motion control method based on Artificial Potential Field(APF)method.This paper compares the concept and characteristics of the field and the environment of the highway accident section,introduces the APF theory into the accident section of highway.Considering various factors that affect vehicle movement and the behavior characteristics of vehicle lane changing,an artificial band-like potential field or point-like potential field is established for lane-changing vehicles,and the lateral movement control and longitudinal speed control of the vehicle are carried out respectively.This model distinguishes vehicle types according to the characteristics of fleet and vehicle speed,and a hybrid model is used to perform different control of the vehicle.(3)In terms of vehicle lateral motion control,this paper proposes an effective fitting model based on NGSIM dataset.According to the lateral movement characteristics and acceleration distribution of the vehicle lane change,two acceleration fitting models for the lateral movement of the vehicle lane-changing are proposed.With the NGSIM dataset,the parameters are calculated and errors are analyzed respectively.The feasibility of the lateral motion model is verified.The more accurate model is used to control the lateral acceleration after comparison.(4)This paper takes a one-way two-lane highway accident section as an example.It builds a simulation model of both auto-driving and manual-driving vehicles on the highway accident section,and designs a simulation experiment based on the SUMO(Simulation of Urban MObility)platform.The impact of the length of coordination zone is explored,and the results reveal that 300 meters is the proper length.the average speed of the mixed model and the single model is compared under different flow rates to verify that the mixed model has a more significant effect at high flow.Comparisons of the simulation results of 0%,70%,100% of CAV controlled by this model under different traffic volume are put.The three indicators of average time loss,average speed and standard deviation of time loss are used as the evaluation criteria to verify the effectiveness of the proposed model.The results illustrate that under the connected environment,the collaborative model has a significant effect on reducing the negative impact of accidents,improving traffic efficiency,and increasing the fairness of the traffic system in highway accident sections.It can be extended to the future highway system under connected environment.