Research On Signal Coordination Control Theories And Methods About Coherent Traffic Flow Of Urban Road Network

Considering the unbalanced distribution of traffic volume in all regions,local congestion such as blocked intersections and arterial roads occur frequently at large cities.How to design a signal coordination control scheme according to different traffic states has become a new requirement.Sub-area division is the premise of signal coordination control.It is more conducive to select and implement signal control schemes of each sub-area based on the rational division,which can greatly improve the operation efficiency.Therefore,this paper studies the network traffic coordination control theory and method from the aspects of the dynamic partition of city road network,the signal coordination control in quasi-saturated state,the boundary traffic control and the signal grooming control strategy in supersaturated state based on the crisscross pattern of urban road network.And the main work and achievements are summarized as follows:1.Based on the spectral clustering,a method for dividing the dynamic subarea considering different degrees of congestion is proposed.A concept of similarity of degree of saturation is proposed.Based on the traffic degree of similarity and degree of saturation,a link weight model is established and the similar matrices are constructed using the degree of saturation.Based on spectral theory,a dynamic partitioning algorithm based on spectral clustering is designed based on the close traffic correlation and high homogeneity in the sub-area.The dynamic partitioning process of road network is also proposed.In order to evaluate the merits and demerits of different schemes,four indices are put forward to evaluate the results of road network classification,and a detailed analysis and validity verification of the dynamic sub-zone method of road network considering different degrees of congestion are given through case studies.2.For the quasi-saturated state,a coherent flow signal coordination control model is established.By analyzing the traffic arrival pattern between the upstream and downstream intersections,a delay model between signalized intersections is established based on the traffic wave theory.The delay model has no constraint on the signal cycle length and a quasi-saturation state signal coordination control model is established,which get rid of the original coordination model that must meet the same signal cycle length constraint.And genetic algorithm and Transyt hill-climbing method are combined to solve the coordination model.For different signal periods of the two adjacent intersections,taking into account the cyclical changes in the arrival of traffic flow caused by the cyclical fluctuations in phase difference between the intersections,a large cycle phase difference optimization method is established.And the validity of the coordinated control model in quasi-saturated state is verified by Vissim simulation.3.In supersaturation state,MFD(macroscopic fundamental diagram)is used to establish the boundary signal control model and method.The sensitivity of the macroscopic fundamental diagram to the signal control cycle and the green ratio is analyzed.Based on the MFD theory,a boundary signal control strategy is proposed and the boundary signal control model of a single substation is established.A model solving method based on the genetic algorithm.Considering the relationship between the input and output flow between sub-areas,a two-layer optimization model of regional boundary signal control based on MFD was established.A hybrid genetic simulated annealing algorithm was proposed to solve the model,which presents a new way of thinking and new ways for supersaturated boundary signal control.4.For the supersaturated state,a modified macroscopic traffic flow model is used to establish signal grooming model and method.Considering the lane change of vehicles in the road section and intersection blocking,the original macroscopic traffic flow model is improved.For the single congestion intersection,the primary and secondary goals are respectively to eliminate the congestion and the maximum traffic volume at the intersection based on the improved macro traffic flow model.And a congestion control and guidance method for overcrossing the trunk road is proposed based on the cumulative traffic flow path.Aiming at the problem of the road network congestion,c congestion control and guidance method combining control and guidance is proposed.And a new method based on chaos search is proposed,which provides a new method for congestion control in supersaturated state.