Research On Integrated Modeling And Control Of Urban Traffic Corridor

The domestic and foreign practices proved that the strategy of relying only on speeding up transportation facility construction to ease traffic congestion is becoming increasingly unworkable.As a result,people began to focus on advanced traffic management and control technology.Among the existing roads,freeway is a relatively closed system that is continuous traffic flow;and crisscrossed characteristic of urban roads make it be interrupted flow.These two different traffic flows are connected via the on-ramp.Therefore,the ramps and its adjacent intersections are the "throat" of the switch urban continuous traffic flow and discontinuous traffic flow conversion.Control the traffic corridor to cause smoothly,efficient transformation of the two traffic flows is of great significance to the whole traffic system.In this paper,the urban traffic corridor is taken as the research object,and the control theory method is applied.The paper puts forward regional boundary control and network integrated modeling and control methods,including:??Cooperative control method of traffic network boundary and entry and entrance rampsFirstly,the number of vehicles on the links is chosen as the state variable and the regional boundary input is chosen as the control input variable,and then the state space model of urban traffic network boundary control is established,by which urban traffic network with arbitrary topology can be modeled.Furthermore,the macroscopic fundamental diagram model is obtained through the network flow data,and the maximum capacity of the network is determined.The control objective of the regional road network traffic flow distribution equilibrium is established,and the linear quadratic optimal control method is used to solve the optimal control law of regional network boundary input,and then the overall control framework of network boundary and internal signal is proposed.At the same time,considering the convergence of regional road network and freeway,the paper puts forward the cooperative control strategy.Finally,the simulation results show that compared with the fixed timing method,this method can achieve the maximum capacity of the network and reduce the network delay greatly.??Integrated modeling and optimal control of traffic networkFirstly,the traffic flow model of each component is established by applying the storage-forward network traffic modeling method to the urban traffic corridor formed by urban road network,freeway and entry and entrance ramps.Furthermore,the quadratic performance index of the integrated traffic flow model is proposed,and the linear quadratic optimal control method is used to solve the problem.Finally,the network simulation environment is constructed and the simulation results show that:compared with the fixed timing method,this method can effectively improve the traffic capacity of the road network,and reduce the average delay and the number of stops.Compared with the cooperative control method,the overall performance of the road network is improved effectively and change smoothly when using the integrated modeling and optimal control method.