Research On Cascading Failure Model Of Urban Rail Transit Network Based On Complex Network

As an important infrastructure of urban public transport,urban rail transit network has certain the characteristics of strong transport capacity,fast transport speed,high punctuality rate and low cost.It is the most important means of transportation for citizens,which greatly alleviates the increasingly serious urban traffic congestion and plays an important role in ensuring urban traffic safety.However,the complex operation environment of urban rail transit network makes emergencies have a huge impact on the network,which is easy to cause site failure,and even cascade failure.Therefore,the research on cascading failure of urban rail transit network has important research significance and social value to enhance the robustness of urban rail transit network.In order to reduce the risk of cascading failure in urban rail transit network,this paper uses complex network theory to study the cascading failure model of urban rail transit network.The specific research contents are as follows :Firstly,by analyzing the complexity characteristics of urban rail transit network,the Space L method is used to establish the urban rail transit network model.Based on the data of rail transit network in New York City,the weighted rail transit network model in New York City is established.The topology characteristics of the network are simulated and analyzed,which shows that the network has small world characteristics.Secondly,the key station identification method of urban rail transit is studied.Aiming at the problem of low accuracy of existing methods for identifying key stations in urban rail transit network,an algorithm for identifying key stations in urban rail transit network based on importance evaluation matrix is proposed.By analyzing the influence of passenger flow factors on urban rail transit network,the importance contribution value of station is comprehensively characterized by passenger flow proportional coefficient and node efficiency,and the importance evaluation matrix considering local and global information of station is designed.Simulation results show that reasonable adjustment of importance contribution coefficient can improve the identification accuracy of key stations.The key station recognition algorithm proposed in this paper makes up for the lack of low recognition accuracy of existing methods,and has certain advantages.Finally,in view of the fact that the existing cascading failure models often ignore the passenger flow factors and lack of considering the dynamic transfer changes of passenger flow in failed stations,a cascading failure model of urban rail transit network based on residual load redistribution is established.The model uses the importance evaluation results of the importance evaluation matrix to define the initial load of the station.Combined with the dynamic transfer characteristics of the passenger flow of the failed station,the residual load redistribution strategy based on dynamic edge weight is proposed.The simulation results show that reasonably defining the initial load of the station and adjusting the parameters of capacity coefficient,overload coefficient and probability adjustment factor can effectively improve the anti-cascading failure ability of urban rail transit network and improve the invulnerability of the network.