Research On Delay Propagation Mechanism Of Urban Rail Transit Network

With the increase and extension of urban rail transit lines,some cities have realized the network operation of rail transit,which not only brings convenience to urban traffic,but also brings huge pressure to traffic organization and passenger transport organization.The train delay in the normal operation of urban rail transit due to force majeure factors such as operation accidents and faults will cause different degrees of influence in the road network.In particular,the morning and evening peak,major events and festivals will cause great social impact and economic losses.Therefore,based on the analysis of the delay characteristics,this paper makes a deep research on the propagation range and duration of delay,so as to effectively improve the operation safety of urban rail transit network.Firstly,this paper analyzes the causes of urban rail transit delay and its propagation and dissipation characteristics,regards the rail transit operation system as a discrete event dynamic system,establishes a line train delay propagation model,and recurs it to the network train delay propagation through the transfer station.Secondly,the topological structure and propagation dynamics of urban rail transit network are studied,and the station delay propagation dynamics model based on SIR is established.On this basis,the CA-SIR model describing the interaction of station delay is built with cellular automata to realize the simulation of delay propagation.Finally,taking Shanghai urban rail transit as an example,the paper puts forward the strategy of delay dissipation from the aspect of traffic organization adjustment.The specific contents of this paper are as follows:(1)This paper analyzes and deals with the historical operation accident data of Shanghai urban rail transit,and makes statistics on the specific causes of the delay.According to the causes of delay,the delay can be divided into initial delay and joint delay.The propagation and dissipation characteristics of delay are analyzed from the redundant time of train diagram reserve.(2)This paper puts forward a delay discrimination method based on train arrival and departure time,regards the urban rail transit network as a discrete event dynamic system,establishes a train delay propagation model according to the planned operation time and initial delay time of the initially delayed train,and linearizes the model by using the maximum algebra method,meanwhile,the model can calculate the logarithm of the initially delayed trains as a follow-up simulation basis of CA-SIR model.(3)This paper studies the complex network characteristics of urban rail transit network,constructs the topological model of Shanghai urban rail transit network,constructs the SIR model of delay propagation based on the scale-free network characteristics of the network and the similarity between virus propagation and delay propagation,and realizes the average trend analysis of the stations affected by delay.(4)Considering that SIR model can't describe the evolution process of individual station with delay propagation,CA-SIR model of delay propagation is built with cellular automatic mechanism.Taking Shanghai urban rail transit network as an example,the simulation study of delay propagation under Zhaojiabang road vehicle fault is carried out based on the statistical initial delay data,and the range and influence time of delay propagation under the fault are obtained.(5)In view of the operation problems caused by delay propagation,this paper studies the delay dissipation measures from the aspect of traffic organization adjustment,and establishes the corresponding train skip stop scheme model.Based on the above simulation results,a case analysis is carried out to obtain a relatively reasonable traffic organization adjustment scheme.According to the location and type of the accident(fault),this paper predicts the initial delay time,calculates the scope and duration of the associated delay,which can provide theoretical basis for the operation of urban rail transit to deal with the traffic organization and passenger transport organization under all kinds of accidents(faults),and control all kinds of losses in time.