Research On Operation Organization Optimization Of Railway Junction Terminal Transfer Train Under The Condition Of Timely Pick-up And Delivery

Railway junction terminal,as a key component of railway network,undertakes all wagonflow organization in the junction terminal area.The operation mode and operation level of the junction terminal wagon-flow organization are directly related to the quality of the wagonflow organization in the junction terminal area.As an important link between marshalling station and freight stations in the railway junction terminal,the junction terminal transfer train ensure the smooth and orderly flow of wagon and good in the junction terminal area.Considering the operation organization method of junction terminal transfer train under the condition of timely pick-up and delivery,it will play a vital role in speeding up freight wagon turnover,satisfying the timely loading and unloading operation of freight stations in the junction terminal,ensuring the full-axle running of departure trains on time at marshalling station,and ensuring the high-quality and efficient operation of trunk transportation network.Starting with the problem of dynamic wagon-flow allocation optimization of marshalling station under the phase plan,the paper discusses the collaborative optimization relationship between the wagon-flow connection and continuation of marshalling station and the pick-up and delivery operations of freight stations in the junction terminal of junction terminal transfer train.By constructing the optimization model of dynamic wagon-flow allocation of marshalling station and the optimization model of operation organization of junction terminal transfer train under the condition of timely pick-up and delivery in the junction terminal,and the collaborative optimization algorithm for the dynamic wagon-flow allocation in marshalling station and the operation organization of junction terminal transfer train under the condition of timely pick-up and delivery is designed,through the cases analysis,the practicability and effectiveness of the model and algorithm are verified.The main research contents of the paper are as follows:(1)Analyzing and summarizing the current situation and predicament of railway freight transportation in China,points out the main contents of railway freight transportation reform,and analyzes the necessity of timely pick-up and delivery of railway junction terminal wagonflow and the importance of operation organization of junction terminal transfer train under the condition of timely pick-up and delivery.Analyzing the influence of timely pick-up and delivery on the railway junction terminal wagon-flow organization from two aspects of the characteristic and operation type of junction terminal wagon-flow,discusses the functional orientation of junction terminal transfer train in railway junction terminal,and analyzes the relevant factors affecting the operation organization of junction terminal transfer train,including locomotive operation times,operating route selection,determination of the number of wagons organized,and the connection with departure train.Sorting out the functions of junction terminal transfer train in station operation plan,including shift plan,phase plan and shunting operation plan,making the contrastive analysis of the formulation of operation organization strategy of junction terminal transfer train under the traditional mode and the condition of timely pick-up and delivery,including the formulation method and basis of train formation plan and locomotive operation plan.(2)The concept of time satisfaction is introduced.The time satisfaction function is classified and studied.The function curves and expressions of seven kinds of time satisfaction functions are discussed respectively,such as linear time satisfaction function,concave and convex time satisfaction function,sinusoidal and cosine time satisfaction function,time satisfaction function of ascending and descending half normal distribution,time satisfaction function of ascending and descending half(38)distribution(gamma distribution),time satisfaction function of ascending and descending exponent Sigmoid,time satisfaction function of ascending and descending half Cauchy distribution.The connotation,characteristics and application scope of soft and hard time window are analyzed,and the expression forms,determination methods and guarantee means of customer time satisfaction when different types of time window are used to construct model under the condition of timely pick-up and delivery are discussed.(3)The dynamic wagon-flow allocation problem of marshalling station is summarized and analyzed,the dynamic wagon-flow allocation optimization model of marshalling station under the condition of timely pick-up and delivery is constructed.The model starts with three important phases in the process of dynamic wagon-flow allocation of marshalling station,i.e.arrival train break-up,wagon-flow connection and continuation,departure train formation.According to the three sub-processes above,the break-up plan sub-model,wagon-flow connection and continuation sub-model and formation plan sub-model are constructed respectively.From the perspective of the whole process of the dynamic wagon-flow allocation of marshalling station,all states of the wagon-flow during the phase plan are completely depicted from the beginning to the end.(4)The key factors of the operation organization optimization of junction terminal transfer train is analyzed,the relationship between the operation organization of junction terminal transfer train and the VRPSPDTW under the condition of timely pick-up and delivery is analogized,and the operation organization optimization model of junction terminal transfer train under the condition of timely pick-up and delivery is constructed.By using Dijkstra shortest path algorithm and complex network related knowledge to construct the globally coupled network of the railway junction terminal,and introducing a series of modeling methods such as soft time window and nonlinear constraints,the model meets a series of practical and objective requirements,such as the wagon pick-up and delivery operation of freight station in the railway junction terminal,the dynamic wagon-flow allocation optimization in marshalling station,the punctual and full-axle departure of trunk transfer train in marshalling station.And it reflects the whole process of operation organization of junction terminal transfer train objectively and truly.(5)A collaborative optimization algorithm for the dynamic wagon-flow allocation in marshalling station and the operation organization of junction terminal transfer train under the condition of timely pick-up and delivery is designed.Based on the analysis of the time connection relationship between them,a sequential algorithm including iteration idea is used to solve the dynamic wagon-flow allocation optimization problem of marshalling station.According to the optimization results,and the results is used as the known data of the operation organization optimization model of junction terminal transfer train,and then,the ideal point algorithm is used to solve this model,and the collaborative optimization research of the two problems is completed.(6)Taking Liuzhou Railway Junction Terminal as an example,the optimization models and optimization algorithm constructed in the paper are verified.According to the results obtained from the dynamic wagon-flow allocation optimization model of marshalling station under the condition of timely pick-up and delivery in the first phase,and then,as the input of known data,the operation organization optimization model of junction terminal transfer train under the condition of timely pick-up and delivery is used to solved problem in the second phase,the results obtained from the second phase can be the formation contents and the wagonflow sources for the departure trains that failed or haven't reach the full-axle in the wagonflow allocation during the first phase,and achieves the collaborative optimization of dynamic wagon-flow allocation in marshalling station and the operation organization of junction terminal transfer train finally.Focusing on the problem of railway junction terminal wagon-flow organization,the paper adopts the research idea of gradual deepening and progressive step by step,explores the problems existing in the current junction terminal wagon-flow organization,clarifies the status and role of junction terminal transfer train in the junction terminal wagon-flow organization,combines with the dynamic wagon-flow allocation of marshalling station,the optimization models of the dynamic wagon-flow allocation of marshalling station and the operation organization of junction terminal transfer train under the condition of timely pick-up and delivery are constructed,realize the connection between the two operation organizations in the relationship of the operation time,the pick-up and delivery operation of wagon,and achieves the purpose of collaborative optimization finally.