Research On Coordinated Control Of Urban Traffic Signals Based On Dynamic Subdivision

With the rapid development of economy and the rapid increase of vehicle ownership,urban road network is facing a great test.At present,the increase of traffic demand leads to the increasingly prominent contradiction of traffic supply and demand,which causes traffic congestion and traffic safety seriously restricts the sustainable development of the city.There is a complex relationship between signal control optimization and traffic network operation,and a reasonable signal control scheme can effectively improve the traffic capacity of the road network.With the intelligent development of traffic field,the signal optimization requirements of the city have been improved.Therefore,how to use intelligent technology to design the signal control scheme more reasonably,in order to alleviate the traffic pressure of urban road network is the focus of attention in the current traffic field.Based on the quantitative description of the incidence degree between adjacent intersections,this paper divides the control subarea of the road network and formulates a reasonable signal control scheme according to the traffic characteristics of the control subarea.The research is mainly carried out from three aspects: incidence degree,subarea division,subarea signal control.The main work is as follows:(1)Quantification of the incidence degree of adjacent intersectionsBased on the deep analysis of the influence index of incidence degree between adjacent intersections,the intersection distance,traffic volume and cycle time are selected as the influence factors which are given weights by the entropy method.Then this paper constructs the comprehensive incidence degree model to realize the quantitative description of the correlation between adjacent intersections.(2)Traffic control subdivision based on chameleon algorithmAccording to the incidence degree adjacent intersection,the chameleon algorithm is used to divide the control subarea.In this paper,the average delay time and the average number of stops of nodes are taken as the evaluation indexes,and the results of the chameleon algorithm and combined index division method are compared by VISSIM software,which provides the basis for the later signal control strategy.(3)Subarea signal controlTaking the maximum capacity of subarea as the optimization goal,considering the intersection saturation,green light time and cycle time,the inertia weight and learning factor of particle swarm optimization algorithm are improved,and the improved algorithm is used to obtain the optimal signal timing scheme.The effectiveness of the improved algorithm is verified by comparing the average delay time and the average number of stops of the nodes with the signal timing scheme obtained by the unimproved algorithm.Therefore,the research of this paper provides a new idea for signal optimization of urban road traffic network,and has a great guiding significance for signal control.