Research On The Operation Schemes Of Express/Local Trains On The Airport Line Of Urban Rail Transit

With the rapid development of domestic airport hubs,urban rail transit has become an important way to airports connections due to its high-speed,convenient,and low-carbon characteristics.Most of the urban rail transit airport lines need two functions of taking into account urban commuting and external connection.A single operation organization model cannot meet various passengers demand.Therefore,this thesis focuses on the operation mode of express and local trains in the airport line,taking into account the benefits of passengers and enterprises,and proposes a method to formulate operation scheme of express and local trains.The main research contents are as follows:(1)Analyze the development and existing problems of airport access to rail transit,and put forward the significance and necessity of the research on the plan of organizing express/local trains on the airport line.Based on the passenger flow characteristics and functional orientation of domestic airport lines,this thesis analyzes the applicability of express/local trains from factors such as routes,passenger flow,traffic and operating economy,and proposes the conditions that express/local trains should conform.(2)Divide passengers into four categories according to their travel origins and destinations,traverse the set of valid routes,and establish a generalized travel cost model for passengers,so as to analyze the selection probabilities of the four categories of passengers on routes,and lay a foundation for the subsequent solution of express/local trains.(3)Taking the ratio of express/local train departures,the express train stop scheme,and the departure interval of the departure station as the decision variables,fully consider the passenger’s choice,transfer,and detention behavior,and comprehensively take into account constraints such as full load rate,service level,and turn-back capability,then a model of trains without overtaking behavior is established with the goal of minimizing generalized travel cost of passengers and enterprise operating cost.Then,this thesis proposes a method for judging whether a train has overtaken and its overtaking position,adjusts operation scheme after overtaking,and establishes an optimization model of express/local trains that considers overtaking.The multi-objective is transformed into a single-objective by linear weighting,and the model is solved by genetic algorithm.(4)Taking Chengdu Metro Line 18 Phases 1,2,and 3 as the research object,analyze its line conditions and the characteristics of peak,flat and low-peak time-space passenger flow,and solve its all-day express/local operation scheme.According to the operation scheme,the benefits of passengers and enterprises are saved by 2.56% and 0.5% respectively during peak hours,and 3.21% and 0.67% respectively during off-peak hours.In addition,based on the analysis of the limited express trains on Line 18,it is concluded that the limited express trains cannot be operated during peak hours,and the plan of combining express trains and local trains is preferred during the off-peak hours,and specila express trains are required at low peaks.