Train Planning Optimization For Through Operation Of Urban Rail

With the developing of the urbanization process in China,many urban lines have shown the network operation characteristics.Under network operation,the traditional independent operation mode has gradually been unable to adapt to the network,while through-operation trains can reduce transfer passenger flow and passenger travelling time,and relieve the organization pressure of stations.The question that how to optimize the train planning for through operation,meeting the travel demand,reducing the operation cost,is one of the key problems to be solved urgently.This paper synthesis the relevant research at home and abroad,analyse the features of through-operation trains.Based on these efforts,this paper does an in-depth study on the train planning optimization for through operation under urban rail,discuss the corresponding theoretical principles and methods.The specific research contents are as follows:First of all,this paper summarize the features of though-operation trains.The condition under which though-operation trains are ought to be planned is discussed from the aspect of passenger characteristics;the condition that influence the operation of though-operation trains is discussed from the aspect of engineering,headways of different trains,carrying capacity of lines and through-operation sections.The requirements for necessity and feasibility of though-operation trains are difined thereby.Secondly,based on the summary of traditional train planning methods,the key link of optimal train planning for through-operation trains are listed according to the features.Combined with foreign operation experience,Beijing’s railway network is taken into a case to study the feasibility of operating environment for through-operation trains at current state.Next,train planning optimization model for through-operation trains under urban rail is proposed according to the feasibility of operating environment and influence factors for through-operation trains.The optimal goal is set as "minimize passenger travelling time,train operating distance and trains’ amount".Comparing to the existing researches,the model in this paper is optimized from two aspects:first,the influence of passengers’ train-taking behavior is considered in the optimal goal with a more reasonable reflection of passengers’ travlling time;second,the constraints takes the carrying capacity of through-operation sections into account,which helps the model results become more realistic.In order to assess the model results,three index are set,which are transfer passenger flow,average full load rate of train and full load rate of train in the section of maximum passenger flow.A genetic algorithm is designed tosolve the model.Finally,a real case is designed in the background of Changping Line and the Eighth Line in Beijing,the validity of model and algorithm is proved by the comparison between the model results and the current operation situation of two lines.In order to enhance the applicability of model,sensitive analysis is conducted from the aspects of site selection of turn-back station,carrying capacity of through-operation section,passenger transferring time and carrying capacity of lines,which can offer advice for the implement of through-operation train planning.