Research On Optimization Method Of Urban Traffic Signal Coordinated Control

With the rapid development of the economy,the population is gradually concentrated to the city,people’s living standards have gradually improved,so the urban traffic developed rapidly.But the construction of city traffic facilities by the space constraints,the growth of the city traffic is far from satisfying the traffic demand of the "mass travel" brought by population is concentrated and increased number of vehicles brought by the improvement of living standards.Traffic problems are more and more serious and have trend of restricting the the city development,so it is of great significance to study the efficient traffic control methods and improve the traffic efficiency of the traffic settings and reduce the pressure of urban traffic.In the existing researches of traffic control,arterial coordination control and regional traffic control tend to optimize and improve the control parameters using the algorithm or method,but the control effect is limited because of the randomness and uncertainty of the vehicle speed.Considering vehicle speed in the research on the coordinated control needs the ideal environment of vehicle road coordination commonly,it is difficult to achieve in the actual environment.Aiming at the deficiency of the above two mothods of coordinated control,this paper attempted to introduce the vehicle speed into the coordinated control,and put forward the idea of setting the meeting point in the vicinity of the intersection.First of all,the traffic coordination control is based on single point control.The higher the flexibility of the single point control,the better the coordination can be used in coordination control.The flexibility of single point control depends largely on the phase structure and phase sequence design.Therefore,the second chapter analysed on the logic relationship of the traffic streamlines in the intersection,contrasted several phase combination,and choose a relatively flexible and wide range of application with dual time line phase combination.Secondly,the third chapter analyzed the traffic meet problems in arterial coordination control,summed up the characteristics that meet position of traffic released periodically at both ends unchanged,tried to introduce vehicle speed into the arterial coordination control,setted the meeting point in the vicinity of the intersection,and summarized the setting method and the corresponding parameter calculation formula.The characteristic of this method is,at the same time of improving the bandwidth,the maximum to avoid green wave disappear dued by the large difference of the two-way traffic flow arrival time.Then,the arterial coordination control optimized methods based on setting meeting point in the vicinity of the intersection and the common arterial coordination control methods simulated in different simulation environments with different saturations.The simulation results show that when the saturation is high,Without reducing the amount of traffic,the former significantly shortens the travel time and also improved the delay time.Finally,the fourth chapter attempts to apply the method of setting the location of the meeting points to the regional traffic network.In this process,with the increase of the road network layer by layer,the problem increased.In order to solve these problems,the fourth chapter put forward several methods to adjust the starting time of green light.These methods basically meet the expected target of regional road network application,and provide a valuable reference for traffic coordination control.The research contents of this paper are progressive,from the single point control to bidirectional green wave coordinated control,simulation experiments proved the feasibility of the method of setting meet point position,the simulation results showed the effectiveness of this approach.At last,the method is applied to the regional road network,which provides a new way for traffic coordination control.