Analysis And Control Of Traffic Flow In The Connected Autonomous Driving Environment

The expressway is the main road of urban transportation and undertakes the main transportation task of the city.The operation status of the expressway is related to the transportation capacity of the entire urban road network and affects the production efficiency of the city.Ramp merging area is the link of road connection.Here,due to the mutual interference between ramp traffic flow and mainline traffic flow,the regional traffic flow operation is poor,and accidents are high,which becomes the bottleneck area of the whole road.According to the statistics of expressway accidents in China,the incidence of traffic accidents and traffic violations in the confluence area of the ramp is significantly higher than that in the main line section,and its traffic conditions and operating efficiency are very important to the operation of the entire road network.At present,China’s urban road framework has been basically determined,and the large-scale expansion of roads and traditional traffic management measures have encountered bottlenecks.With the emergence of automatic driving technology,it brings dawn to solve traffic congestion,traffic safety and traffic pollution reduction.Autonomous vehicle technology uses advanced sensors,cameras and communication technology to capture the driving environment of the vehicle,and provides driver control or direct control of the driving state of the vehicle through the on-board computer.In view of this,this paper takes Hongxu Road,an expressway in Shanghai,entering the ramp area of Yan’an West Road as the research scene,and takes the expressway traffic flow as the research object,analyzes the operation characteristics of expressway traffic flow under the traditional conventional driving environment and the network connected automatic driving environment,and uses the traffic simulation software SUMO to build the physical microscopic simulation model of the expressway ramp confluence area,The smart driver(IDM)car following model and LC2013 lane change model are used to establish the micro model of conventional driving vehicles,and the collaborative adaptive cruise control(CACC)model and LC2013 lane change model are used to establish the micro model of networked autonomous vehicles.The model parameters are calibrated in combination with relevant research.The basic map model,speed space-time trajectory,collision time,and gas emissions are calculated,realize the analysis of the operation status(flow,speed,density),safety and environmental impact of the traffic flow in the bottleneck area of the expressway entrance ramp under the traditional environment and the network connected automatic driving environment.According to the characteristics of expressway ramp merging area,the ALINEA ramp control is realized by SUMO-Python joint simulation.