Collaborative Optimization Of Carflow Allocation For Freight Trains Based On Adjacent Technical Stations Under The Condition Of Fixed Time And Fixed Train Length Of The Traffic Flows

With the fast development of logistics industry in China in recent years,the competition between railway freight transportation and other modes of transportation is increasingly strengthened.Realizing the expedited and logisticalized transportation of goods,and gradually shifting the demand of increasing "quantity" to the requirement of improving "quality",is the development direction of railway freight transportation to adapt to and serve the social economy.The railway is a large system with multi-unit linkage operation,and the technical station is a significant unit of the railway transportation network.Its transportation organization mode directly affects the turnover efficiency of trucks in the regional road network.and benefit are of great significance.For a long time,most of the flow distribution problems are based on a single technical station,and the single-point information is isolated,and there are limitations in the decision-making of operation plans.In fact,the technical stations of the railway network are interrelated.If the adjacent technical stations are regarded as a whole,the operation organization of the technical stations can be improved from the perspective of operation coordination among the technical stations,which can effectively improve the operation efficiency of the technical stations and the turnover of trucks,and will definitely achieve better results.Great transportation benefits.Under the background of railway freight logistics,researching the coordinated distribution of freight trains between technical stations has academic worth and down-to-earth meaning for getting the utmost out of transportation capacity and improving freight service quality.Therefore,this thesis studies the problem of flow distribution optimization from the perspective of cooperative operation of adjacent technical stations,and provides theoretical reference for the subsequent research on flow distribution optimization of technical stations.First of all,laying the foundation of detailed description of technical station operation flow,the connotation and traits of the wagon-flow allocation of a single technical station are analyzed and summarized,and the influencing factors that may be related to the distribution operation are discussed.The similarities and differences of station distribution.Then,combined with the operation characteristics of different assembly modes,the transportation organization mode of the coordinated flow distribution of the dual-technology stations under different assembly modes is proposed,which lays an academic base for the modeling and majorization of the coordinated flow distribution plan of the dual-technology stations under the fixed-number and fixed-point assembly modes in the following.Secondly,according to the analysis of the organization mode of coordinated distribution and transportation between technical stations in the mode of set-up and assembly,the strategy of adding and opening is adopted to realize the cooperative operation of adjacent technical stations.After analyzing the realization conditions of the additional trains,combined with the relevant constraints of the traditional distribution model,a dual-technology station under the fixed-arrangement and assembly mode is constructed with the minimum total transportation cost,the maximum total number of trains,and the minimum total vehicle stay time at the station as the optimization goals.Coordinate the flow distribution model and combine with the characteristics of the transportation problem,genetic arithmetic is used to settle itThen,according to the analysis of the coordinated flow distribution and transportation organization mode between technical stations under the fixed-point assembly mode,the fixedpoint assembly mode with relaxed conditions is adopted to realize the cooperative operation of adjacent technical stations.After analyzing the impact of under-axle trains,combined with the relevant constraints of the traditional flow distribution model,a dual-technology station collaborative flow distribution model under the fixed-point assembly mode with the minimum total vehicle stay time at the station as the optimization goal was made up,the grey wolf arithmetic is improved to solve the model.Finally,combined with a numerical example,the optimal scheme for cooperative operation of two technology stations under different assembly modes is obtained,and it is compared with the operation scheme effect of the two stations when the flow is distributed independently.The solution results further verify the different assembly modes proposed in this thesis.The rationality of the coordinated flow distribution optimization mode of the lower double technical stations.This thesis mainly solves the majorization of wagon-flow allocation of technical stations,breaks through the limitations of a single technical station,clarifies the advantages and importance of collaborative operation between technical stations in the road network,and builds an optimization model for the coordinated flow distribution of dual technical stations under different aggregation modes.Effectiveness of models and algorithms.The research consequences can offer some ideas for the future study on the optimization of flow distribution in railway technical stations.