| Urban traffic congestion is becoming more and more serious.The current traffic management mode mainly alleviates traffic congestion through traffic distribution and traffic signal control.Among them,traffic allocation influences the route choice of travelers through urban traffic network management to realize the spatial separation of traffic flow in the road network.Common methods include static and dynamic traffic allocation.Road network and traffic signal control through direct configuration of traffic signal controller,adjust the signal timing parameters,realize the separation of traffic demand in time,control methods including single point of control,road control and area control,regional traffic signal control is mainly through the coordination of the traffic network unimpeded signal system improve network performance.Therefore,regional traffic signal control and the process of traffic distribution can interact and restrict each other,forming a unity to coordinate the spatial and temporal distribution of traffic demand.This paper mainly studies the coupling relationship between traffic allocation and traffic signal control,establishes a two-layer model with the upper layer as signal control and the lower layer as traffic allocation,and realizes a regional traffic signal control simulation model based on the traditional Frank-Wolfe algorithm optimal allocation and heuristic algorithm optimal control through Paramics traffic simulation platform.First,the cooperative control model of traffic signal and distribution is established.In the upper layer of the model,a traffic control model based on harmony search algorithm is established to minimize the intersextion delay of regional road network.At the same time,the basic concepts and control parameters of traffic signal control method are expounded.In the lower layer of the model,a traffic allocation model based on user equilibrium was established by using the minimum total trip as the objective function and Beckmann’s user equilibrium allocation model as the basis.The connection between the upper model and the lower model is analyzed in detail.Second,the solution method of cooperative control model of traffic signal and distribution is given.For the upper traffic control model,harmony search algorithm is adopted.Harmony memory database HMS is established through local search,pitch adjustment,memory optimization and other methods.Through iterative convergence,the optimal timing parameters of signals at each intersection in the road network are obtained.Of the lower traffic assignment model,adopting BPR function as road resistance function,OD travel demand of local road network of user equilibrium,and Uses the Frank Wolf algorithm by linear programming,the iterative approximation of nonlinear programming problem solving ideas,at each iteration,the objective function for linearization,get the road network of each section of flow distribution in the optimal solution.Then,the simulation system based on traffic signal and distribution co-control is designed,and the simulation environment,development environment,development process and function modules of the traffic signal and distribution co-control system are established.Based on Visual Studio 2010 development environment,the Paramics simulation system was developed again.The system includes Paramics simulation interface module,Paramics simulation input and output function module,traffic signal and allocation collaborative control sub-module(FrankWolfe allocation algorithm module,HS timing scheme optimization algorithm module)and other three sub-modules,realizing the verification of traffic signal and allocation collaborative control method.Finally,the effectiveness of the cooperative control method is verified.By choosing the independent design "(radius 3 tiles)to be" local area network simulation on the simulation analysis of application of the proposed traffic signal and distributed collaborative control simulation optimization method,the regional system of intersection delay,delay and travel time index compared with before optimization,the result shows that this paper establish coordinated control model can significantly improve the running efficiency of urban area traffic signal control system,enhance the robustness of the control system of urban traffic. |
