Method Of Collaborative Flow-limiting In Multiple Stations Of A Single Line In Uran Rail Transit

While urban rail transit brings convenience, it also causes some new challenges such as passenger congestion . Unlike ground traffic congestion, it is not easy for closed limited rail transit system to evacuate traffic congestion. Traffic congestion will continue to spread with the train's operation, and it may lead to paralysis of the entire system. So how to alleviate the urban railway traffic congestion emerges as a new problem.In this paper, single line urban rail transit is used as the research object, the method of multiple stations collaboratively limiting traffic flow is adopted. The specific research contents include:Analyze the characteristics of urban rail transit network traffic from three aspects:station, line, network. Summarize factors that affect passenger flow distribution including passenger travel characteristics, passenger social and economic characteristics, rail transit network and dynamic evolution of passenger flow; Analyze commonly used rail transit passenger flow assignment model and algorithm.Analyze the meaning of urban rail traffic flow congestion; Analyze the causes of road network traffic congestion from traffic demand, line capacity and network structure these three aspects, and summarize the characteristics of crowded traffic as unbalanced time distribution and the uneven spatial distribution and propagation; Perform researches on Traffic Congestion Propagation Model and propagation; Expatiate the influence of passenger flow, define traffic congestion propagation and related solving algorithm, finally propose congestion control method from three aspects as passenger demand, train capacity and network structure.Elaborate urban traffic limit principles; Determine the flow limit trigger index and its calculation method; Establish a model of cooperative current limiting for urban rail transit which regards the minimum and maximum amount of passenger transportation and retention as the goal, treats the number of platform aggregation and passengers as decision variables,considers passenger demand, station capacity, train capacity and interval transportation capacity as constraints, and solve the problems using genetic algorithm; Generate traffic limiting scheme, improve the flow control process; Finally, taking Chengdu Metro Line 1 as an example, verify the model and algorithm. The results show that the method of cooperative flow-limiting may reduce the full-load ratio of the section and improve the average utilization of the delivery capacity of interval and balance the proportion on board of each station.