Robust Optimization Of Regular Passenger Inflow Control Plan Construction For Urban Rail Transit In Peak Hours

Passenger congestion of urban rail transit in peak hours is a common problem in metropolis,which seriously affects the passenger service level and easily causes operational safety issues.The source of congestion is the contradiction between supply and demand.When the supply of transportation capacity is difficult to effectively improve,strengthening management from passenger demand side is the unique approach to alleviate congestion.At present,passenger inflow control is the congestion response measure in peak hours commonly used in domestic metro cities.In the early stages,scholars have carried out a lot of research on passenger inflow control.However,there is little research on the regular fluctuation characteristics of passenger flow,which leads to the deficiency of the practical application of the inflow control plan.In accordance with the characteristics of passenger flow fluctuation in peak hours,this thesis analyzes the robustness demand of inflow control scheme.and researches the method of regular inflow control plan construction based on robust optimization,in order to improve the reliability and practicability of the inflow control scheme.The main research work of this thesis includes:(1)Analysis of regular fluctuation characteristics of passenger flow in peak hours:Taking relative deviation as an index to evaluate,the thesis quantitatively evaluates the fluctuation of inbound passenger flow and OD passenger flow at different time granularities from levels of line and station,and summarizes the rule of regular fluctuation of passenger flow in peak hours.The results showed that: the passenger flow of rail transit has the characteristic of regular fluctuation.With the curtailing of the analysis period,the fluctuation amplitude of passenger flow increases sharply.The average OD passenger flow fluctuation of passenger flow is as high as 30% under the time granularity of 15 min,so the influence of passenger flow fluctuation on inflow control plan construction should not be neglected.The fluctuation range of passenger flow in different stations is various,which is correlated to the passenger flow structure.Finally,according to the fluctuation characteristics of passenger flow,the robustness demand of the inflow control scheme is demonstrated.(2)Establishment of robust optimization model for regular inflow control plan construction: Firstly,combining the passenger flow structure and train operation process,the passenger impact factor is constructed to describe the space-time relationship between passenger flow and the section on the line.Taking passenger flow demand,station inflow control capacity and section transportation capacity as the main constraints of the model,a deterministic control model is constructed with the objective of minimizing the cumulative numbers of stranded passengers.Secondly,based on the deterministic model,the thesis describes passenger flow split at stations by interval,introduces uncertain budget to control the conservatism of the model,and constructs a bi-level programming model according to the principle of maximizing the influence of uncertain parameters.Based on the duality theory,the bi-level is transformed into a single-layer linear programming model,and then a robust optimization model of inflow control plan construction is established.(3)Empirical study on Beijing Subway Line 5: Based on the model,the deterministic scheme and the robust scheme are worked out respectively,while cumulative numbers of stranded passengers and breakthrough degree of section transport capacity are selected as the evaluation indexes to verify the accuracy and effectiveness of the robust optimization model.The results showed that: By selecting appropriate robust control parameters,the inflow control plan can maintain good performance.Compared with the deterministic scheme,the breakout rate of dangerous section is reduced from 41.15% to 12.92%,and the accumulative breakthrough degree of section transport capacity from 5068 persontimes to 568 person-times.It is concluded that the robust scheme can effectively deal with the potential operational safety risks caused by regular fluctuation of passenger flow and improve the reliability and practicability of the scheme.