Cascading Failure And Passenger Flow Coordinated Control Of Urban Rail Transit Network Under Extreme Events

In recent years,with the continuous accelerating of the process of scale and network of urban rail transit in China,the scale effect has also sharply increased its ability to attract passenger flow.Under sudden events,the large-scale passenger flow can easily lead to overload operation of stations or lines,reducing the traffic efficiency and operational stability of this network.Based on this,this paper focuses on the contradiction between supply and demand in the rail transit network under sudden events,and studies on the aspects of passenger travel behavior,the propagation regularity of the passenger flow,and the collaborative control,in order to improve the level of emergency management.The specific research content is as follows:(1)Summarize the characteristics of urban rail transit passenger flow and the measurements of organization of passenger flow: categorized sudden events and analyzing the historical operational situations from the terms of types of sudden events,frequency of occurrence,consequence and location based on text data.And then attributing passenger flow control as the problem of matching travel demand and capacity of urban transit system,the formation mechanism,propagation and evacuation process of sudden massive passenger flow are analyzed,and the essential types of passenger flow control and organization are summarized.(2)Research on cascading failure of urban rail transit network under sudden events:considering the probability of urban rail transit network passenger flow transferring into road public transportation networks,travel plans consist of urban rail transit,bus,taxi and combination modes corresponding to them are constructed.Then a novel cascading failure model considering the delayed loading of passenger flow is proposed based on MNL and capacity-load models,and taking the urban rail transit network in Beijing as an example,simulating and analyzing the cascading failure and assessing the operation stability.Results show that the duration of sudden events has significant impact on the operational stability of urban rail transit network,and with increasing of the duration of sudden events,the determination behaviors of passengers for travelling are more variable and the process of cascading failure is more difficult to control.(3)Research on passenger flow coordinating control in urban rail transit under sudden events: a novel model for passenger flow coordinating control is proposed based on robust optimism theory considering the loading capacity of platform,the crossing capacity of stations and the capacity of lines.This model takes the time of arriving at stations for trains as the time of changing states of passenger flow,and takes the minimize of delay passenger flow and maximize of in-station passenger flow as optimizing objectives.Taking Beijing rail transit network as an example,the model is settled by the GA algorithm,and the reliability and feasibility of this model is verified.Results show that the passenger flow coordinating control model considering the crossing capacity of stations can be refined the measures of passenger flow control,and can be extremely delayed the time of gathering sudden massive passenger flow and can reduce the impact of sudden events on the efficiency of urban rail transit network.