Design For Train Plan Of Full-length And Short-turn Routing In Urban Rail Transit

With the acceleration of urbanization and the continuous expansion and spread of urban boundaries,urban transportation problems have become increasingly prominent.Urban rail transit has developed rapidly with its own operational advantages.Its radiation range and scale of operations have continued to increase,and passenger traffic has continued to rise,and many cities have emerged the phenomenon of uneven distribution of passenger flow in rail transit lines.If a single-traffic scheme is used to run the train,the train's full load rate is too large in the section with many passengers,and the passenger comfort experience is poor,and the rail transit service level is not high,and the train utilization rate is low in the section with small passenger flow.Thus,transport capacity resources have not been fully and effectively used;If the mode of full-length and short-turn routing operation is adopted,the load intensity of trains in each section can be balanced and the cost of operating companies can be reduced.At the same time,the fairness of train services in each section can be as much as possible,and the quality of passenger services can be improved.The characteristics of passenger flow distribution are the basis of making train operation plan.This paper analyzes the passenger flow distribution characteristics of urban rail transit lines from the perspectives of time and space,and gives a measure of the equilibrium degree of passenger flow cross sections,which provides a basis for determining whether rail transit lines are suitable for large and small intersections.At the same time,the various scheme forms,characteristics and applicability of train crossings are introduced in detail.Based on this,taking Nanjing,Xi'an,and Chengdu as examples,the adaptability of the form of full-length and short-turn routing and the spatial development of large cities are analyzed,the wide range of applications are also analyzed.The main influencing factors for the development of full-length and short-turn routing are discussed,including transportation resources,passenger travel needs,the location of return stations,line conditions.Among them,the passenger travel demand has an impact on the development of the travel plan from the perspective of demand,the line conditions,transportation resources,and the location of the return station have an impact on the development of the travel plan from the perspective of supply.The determination of constraints is based on the above four types of influencing factors,which is the theoretical basis for constructing the objective function of the optimization model and determining the constraint conditions of the model.Based on the consideration of the above-mentioned influencing factors,with the goal of minimizing the cost of passenger travel and minimizing the operating cost of the enterprise,the design and research of the operation schemes of the full-length and short-turn routing are conducted.In determining the passenger travel cost target,this paper first considers the residence time of the second waiting and above during the passenger waiting process,which is more appropriate to the actual waiting situation of the passenger,and establishes a more accurate objective function model with the lowest passenger travel cost.In determining the operating cost target of the enterprise,the relationship between the number of kilometers operated by the train and its formation,departure frequency,and the location of the return station was analyzed,and the objective function model with the shortest total number of kilometers traveled by the train was established.Therefore,a multi-objective optimization model under the constraints of transportation capacity and equipment resources was established after comprehensive consideration of factors such as maximum line capacity,train rating,and maximum capacity,and the model was solved using genetic algorithm programming.Solution ideas and steps was given.Finally,taking Xi'an Rail Transit Line 6 as an example,the full-length and short-turn routing passenger flow data and OD data are analyzed to determine that it is necessary to have a full-length and short-turn routing scheme.The model parameters were determined,the model was constructed,and the genetic algorithm was used to calculate and optimize the model to obtain the best train operation plan.At the same time,the effects of different return stations and train combinations on the train operation plan were analyzed.