Optimization For Train Operation Plan With Full-length And Short-turn Routes Of Virtual Coupling Trains In Urban Rail Transit

With the continuous development of urban rail transit network,the imbalance contradiction between passenger flow demand and transportation capacity becomes more and more prominent.Therefore,we need more flexible modes of operation organization.Virtual coupling uses wireless communication to replace mechanical linkage,which enables trains to be virtually reconnected or disconnected at the station or during operation.Virtual coupling can shorten the traffic interval,increase the traffic density and give full play to the ability of a line to pass.It also helps to improve service levels through transport organization models,and can make various transportation organization modes such as full-length and short-turn routes,express-local train and Y-type routes more flexible.This paper mainly studies the full-length and short-turn routes of virtual coupling trains.Then I set up the double-layer optimization model of train operation plan with full-length and short-turn routes.Then,through a case study,this paper illustrates the feasibility of optimizing the train operation scheme of virtual coupling trains.The main research contents of this paper are as follows:(1)This paper analyzes the tracking interval calculation of virtual coupling trains.Firstly,the changes of urban rail transit in train running interval under virtual coupling is clarified.Then compared with the traditional transportation organization mode,the calculation methods of interval tracking interval and station tracking interval are summarized.The influence of virtual coupling on these parameters is clarified,and the parameter values under different speeds are calibrated.(2)This paper analyzes the transportation organization modes with full-length and short-turn routes of virtual coupling trains.Firstly,the paper focuses on the transportation organization mode with full-length and short-turn routes of virtual coupling trains and train operation process.Then it compares with the transportation organization mode with full-length and short-turn routes in traditional to illustrate its advantages.Finally,the differences between the virtual coupling model and the traditional organization model are analyzed from three aspects of decision variables,objective functions and constraint conditions.(3)This paper builds a double-layer optimization model for full-length and short-turn routes of virtual coupling trains.In this paper,the constraints of train departure frequency and the number of marshalled trains are fully considered.Then,a two-level optimization model of full-length and short-turn routes of virtual coupling trains is constructed,and the solution method based on multi-population genetic algorithm is designed to solve it.The model takes passenger travel time cost and enterprise operation cost as the upper objective function.And the model takes the equilibrium of the full-load rate of trains in the short-turn route as the lower objective function.(4)This paper takes Metro Line M as an example for case analysis.Firstly,this paper introduces the general situation of Metro Line M,and analyzes its passenger flow distribution characteristics.Then the multi-population genetic algorithm is used to get the train plan with full-length and short-turn routes of virtual coupling trains.In this paper,the waiting time of passengers,the running kilometers of trains,the number of vehicles used,the balance of the full-load rate of trains in the short-turn route,the maximum full-load rate and the average full-load rate in the short-turn route are selected as the evaluation indexes.Then,the train plan with full-length and short-turn routes of virtual coupling trains is compared with the single train plan and the traditional full-length and short-turn routes plan.Finally,sensitivity analysis is carried out on three key technical conditions: train operation frequency,the location of small routing turn back station and the number of train marshalling vehicles.It makes clear the influence of different technical conditions on each evaluation index,and provides support and reference for the train operation plan with full-length and short-turn routes of virtual coupling trains in urban rail transit.The case shows that the transportation organization mode of virtual coupling trains has significant advantages.20 figures,18 tables,and 61 references.