Research On Optimal Control Of Arterial Green Wave Considering Subdivision And Interval Coordination

With the further deepening of urbanization and the rapid development of the national economy,the living standards of residents have gradually improved,and the number of car ownership has increased steadily.As a result,traffic demand keeps increasing,and road traffic problems such as traffic congestion and exhaust pollution are becoming more and more serious,which has affected the daily life of residents seriously.As an important node of the urban road network,the intersection directly affects the accessibility of the urban road.Accordingly,optimizing the signal control of the intersection is an important means to solve the urban traffic problem.However,as the main carrier of urban roads,the arterial road undertakes a large amount of traffic load.Therefore,the implementation of coordinated control for arterial road to ensure the smooth flow of arterial lines has an important role in improving the capacity of road networks and alleviating a series of traffic problems.On the basis of summarizing and analyzing the current status of research,this paper studies the methods of coordinated control of the arterial road,division of control sub-regions and coordinated optimization of adjacent sub-regions according to the deficiencies of the existing research.The main research contents are as follows:First of all,the main methods of arterial coordinated control are explored.By analyzing and comparing the advantages and disadvantages of different methods,the AM-BAND(Asymmetrical Multi-BAND)model is selected as the basic model of this paper.Aiming at the shortcomings of the design of the arterial line coordinated control scheme based on the average vehicle speed in the traditional maximum green wave band model,combined with the actual situation of vehicle speed fluctuation during driving,the speed interval at the 95% confidence level was selected as the green wave speed fluctuation interval.As a result,corresponding constraints are added to the Asymmetrical Multi-BAND model,a trunk green wave coordinated control model considering the speed fluctuation interval is established,and the solution method is introduced in combination with the characteristics of the model.Secondly,in view of the constraints on the effect of the coordinated control of the arterial line,this paper realizes the coordinated control of large-scale arterial lines through the division technology of control sub-region.Considering the problems in the existing research that the sub-region division and the coordinated control are separated from each other,which leads to neglecting the influence of the sub-region division on the arterial coordination control effect,three 0-1 variables are introduced based on the relationship between the intersection,the road segment and the control sub-region.The variables combine the sub-region division with the coordinated control process.Based on the green wave coordinated control model for arterial line considering the speed fluctuation interval established above,the control sub-region division model is established with the objective function to maximize the mean value of green wave bandwidth between adjacent intersections.According to the characteristics of the model,genetic algorithm is chosen to solve it.Thirdly,in order to strengthen the coordination optimization of adjacent sub-regions,this paper introduces the concept of effective green wave time.By analyzing the composition of the straight traffic on the arterial line,a staged function of the traffic flow into the downstream sub-region is constructed.Taking the maximum number of vehicles arriving at the first intersection of the downstream sub-region from the last intersection of the upstream sub-region during the effective green wave time as the objective function,the adjacent sub-region coordination optimization model based on continuous traffic is established to optimize the phase difference and a specific algorithm is given.Finally,this article takes Zhongguancun Street as a case.According to the field survey data,the sub-region division model and the sub-region coordination and optimization model above are calculated and solved,and simulation analysis is performed by VISSIM software.Simulation results further confirm the superiority of the above model in implementing coordinated control on large-scale arterial lines.