Traffic Control Method Research Of Non-signalized Intersection Under Connected Vehicles Environment

Traffic congestion has became one of the daily travel problems of urban residents,which will lead to the loss of travel time,the increase of pollution emissions and traffic accidents,and its economic loss is equivalent to 5%-8% of GDP.As the key node of traffic congestion,traffic accidents,traffic delays and exhaust emissions are mostly concentrated here.How to effectively organize traffic at the road intersection has became one of the key measures to alleviate urban traffic congestion.With the development of Connected Vehicles,it provides some new ideas to solve the problem of traffic congestion.In this paper,the technology of Connected Vehicles is used to build an non-signalized intersection system,and gap theory is used to study the centralized optimal control method of the non-signalized intersection in Connected Vehicles environment.The paper designed an non-signalized intersection control system based on the technical features of I-VICS,gap acceptance theory of non-signalized intersection and "right of way" theory,formulate the information interaction strategy of vehicle,roadside equipment,central control center,and plan the optimal control process of non-signalized intersection.Based on the safety and high efficiency of non-signalized intersections,three optimal control methods are designed for different intersections:(1)A CV-LL(Connected Vehicles-Low Flows and Low Flows)optimal control method is designed for the intersection of low traffic flow.The method constructs a model with acceleration and speed as variables.The acceleration is optimized to influence the vehicles' s speed to guide themselves to pass through the intersection safely and efficiently,and a genetic algorithm is designed to solve the model;(2)A CV-LH(Connected Vehicles-Low Flows and High Flows)optimal control method is designed,which is suitable for the intersection of low flow and high flow.By adjusting the headway of high flow,low flow vehicles can cross each other at a suitable speed,and genetic algorithm is designed to solve the model;(3)A CV-HH(Connected Vehicles:High Flows and High Flows)optimal control method is designed,which is suitable for the intersection of high traffic flow.This method optimizes the vehicle head clearance of each entrance road of the intersection by adjusting the vehicle position algorithm,so that the vehicles can travel safely and efficiently at the optimal speed.Finally,three groups of experiments are designed to scientifically establish the comprehensive evaluation function SEF to evaluate the effectiveness of the optimal control model from four aspects of emission,efficiency,safety and reliability:(1)the effectiveness of the optimal control method is verified by the comparative simulation experiments of three groups of actual intersections in the traditional driving environment and three types of unsignalized intersections in the Internet of vehicles environment VISSIM simulates the signal-free intersection of Ninghai line(Hai'an County section)and Xinglong Road,the signal intersection of Zhongxin Avenue and Fangzhong street,the signal intersection of Zhongxin Avenue and Zhongnan street,and then compares the signal-free intersection of optimized control method under the environment of vehicle networking through VISSIM joint simulation.The simulation results show that the three optimal control models can improve the overall benefit of the intersection,the vehicle emissions,parking time and delay are reduced,the reliability and safety of average speed and travel time are improved respectively.(2)The comparative simulation experiments of three optimal control models are used to define the flow limits of the control methods under different inlet flow of the designed intersection.It is concluded that when the flow of each inlet is within [1001000](PCU / h),the cv-ll and cv-hh optimal control models are suitable;when there are two inlet flow within [1001000](PCU / h)at the intersection,the flow of the other inlet is within [1000],In 1900(PCU / h),cv-lh optimal control model is suitable;in other cases,cv-hh optimal control model is the best.(3)In order to verify the superiority of the proposed method,the comparative simulation experiment between the proposed optimal control model and the existing optimal control method is designed.It is found that the proposed cv-hh optimal control model can improve the overall operation efficiency of the intersection,which is superior to the existing phase like control method,SIS control method and speed control method.