Intersection Signal Control Strategy Based On Depth Period Division

With the development of economy,the increasing demand for transportation leads to the increasingly serious problem of traffic congestion,which has a serious impact on people's quality of life and economic development.Therefore,traffic congestion is one of the most important and urgent problems in the current urban development.At present,there are many researches on traffic signal control,but the problem of traffic congestion can not be effectively solved.The main reason is that the informatizati on level of infrastructure of most intersections in our country is relatively low,which is difficult to meet the accuracy and real-time required by signal control;in signal control,the current time division basically relies on manual experience,with low accuracy.For the undersaturated state,the actual traffic demand is not considered,and the phenomenon of air release and secondary queuing is serious.For the saturated and oversaturated state,there is a lack of consideration on channelization of associated intersections,and the coordinated control strategy has some shortcomings.In this paper,the above problems are studied and explored.In this paper,the intersection data is used,which has the characteristics of wide distribution,accurate data and easy access.It is of great theoretical and practical significance to analyze and apply the data of intersection signal timing.This paper focuses on the research of intersection signal control strategy based on depth time division:(1)Through analyzing the relationship between traffic data,first,the flow data is divided into time periods by using the order clustering algorithm based on Fisher optimal segmentation,and then K-means clustering algorithm is used to divide the state.Through the above two steps,the segmentation points of time series and flow state are obtained.Then,the time division results of traffic data are obtained by combining the segmented points of time series with state values.The method has some improvement effect on the situation that there are many discrete points after clustering by K-means and improves the ability of using Fisher optimal segmentation algorithm to identify the time period state.(2)In view of the time period of under saturation,a signal timing method based on traffic demand is proposed.The method analyzes the arrival and departure of vehicles,and gives the green light duration required for vehicle traffic by combining the para meters of start delay,headway and vehicle arrival rate.The mathematical relationship between traffic flow,vehicle arrival rate and green light time is established,which makes the signal timing meet the traffic demand of each phase,and can effectively avoid the occurrence of secondary queuing and air discharge.(3)A coordinated signal control method based on capacity is proposed for the period of saturation and supersaturation.Firstly,the capacity of lane groups of key intersections and upstream intersections is associated,and then the bearing capacity of the sections between the key intersections and the downstream intersections is associated to obtain the green light time in the coordinated direction of the key intersections,and the rest phases ar e allocated reasonably according to the flow ratio.The method can ensure the capacity of key intersections by coordinating the upstream and downstream intersections,and meet the traffic demand of other phases.(4)The above three research contents are integrated,and a set of intersection time division and signal control methods are designed.Through simulation verification,the original timing scheme,Webster model and the scheme in this paper are compared.Simulation results verify the effectiveness of the proposed method.