Premeter Control And Simulation Optimization Of Critical Area Based On MFD

The urban road network is complex in space and the road condition is ever-changing in time,which poses a severe challenge to the urban traffic control.Obviously,when controlling the traffic,it is very difficult to accurately describe the whole road network through mathematical model,let alone to solve the problem of urban congestion once and for all.Therefore,it is a more scientific and sustainable method to grasp the key points and re-radiate the whole network.In this thesis,areas with regular traffic congestion and areas with severe traffic congestion caused by emergencies are defined as key urban areas.This kind of area is characterized by the strong homogeneity of the crowded space and time and more compact.According to the different spatial and temporal distribution of congestion to be governed,congestion governance can be divided into two situations: normal governance and sudden governance.In this thesis,two key areas,the upstream urban road network under highway control and the surrounding road network under metro service interruption,are selected to conduct perimeter control research,so as to observe the effects of the macro-micro composite perimeter control proposed in this paper in normalized governance and emergent governance.The specific work is as follows:Firstly,the method of model predictive control(MPC)is used to construct the macro perimeter control model.With the help of MFD,the road network attributes in key areas are obtained through SUMO micro-simulation and transferred to the MPC model to calculate the corresponding predicted values.Then the predicted values are fed back to the genetic algorithm to optimize the macroscopic control parameters.Finally,the optimized control parameters are transferred back to the macro control model and micro control module to realize the model predictive control.Secondly,a micro perimeter control method which can divide gated intersections in real time is proposed.The micro control process includes two parts: traffic flow guidance control and perimeter signal control.The former predicts the queue length at the next moment by the Kalman filter method and divides the gated intersections in real time.In the latter,the control parameters obtained by the macro perimeter control module are converted into signal timing parameters of the gated intersection and transmitted to the micro simulation platform.Finally,the SUMO micro simulation platform is used to implement the simulation experiment.Relevant parameters calculated by the micro-control method will be fed back to the SUMO micro-simulation platform through the Traci interface for micro-simulation.By analyzing the corresponding indexes obtained from the micro simulation,the simulation results show that the macro-micro composite perimeter control strategy proposed in this paper has good effects in both normal governance and sudden governance.