| In recent years,in the field of railway transport in China,the rate of passenger flow attract by the high-speed railway network getting higher,Freight traffic on the existing lines is gradually becoming more relaxed.As a result,the quality improvement of freight train transport service has a prerequisite.At present,as China’s railway freight transport sector mainly adopts an organizational mode of transport organization,it leads to poor planning and regularity of freight transport,which in turn leads to low timeliness of transport and opacity of the transport process;nevertheless,to damage the image of railway freight in the transport market and reduces the level of competitiveness in relation to other modes of transport.Therefore,the design of a reasonable freight train formation plan for the characteristics of the freight flow and other factors to ensure the regularity of the planning and organization of the flow of cars,can be fixed in the planning stage of the scattered traffic to make a fixed organization,so as to make the whole process of cargo flow,car flow of the transport process of economic transparency.The paper proposes a hierarchical organization technique for the compilation of cargo train formation plans,taking into account the characteristics of China’s railway transportation network and the method of cargo transportation organization.The method of selecting and delineating the scope of the cycle accumulation centres has been established in conjunction with the pattern of our railway network.A group planning model based on a concave function operator is built to solve the problem using a particle swarm algorithm.The method is verified by actual data and network structure.The main research of the paper consists of the following.The method of planning and preparing the accumulation of trains at cycle technical stations is proposed,which can make use of the large and stable traffic flow at technical stations to attract small traffic in the vicinity,and solve the problem of unplanned and irregular organization of small traffic using traditional transportation methods.The theory of the accumulation area system is proposed,which enables the flow of small cars from loading stations within a certain range to stations with certain technical operating equipment conditions and the ability to adapt operations,and gives a method for selecting cycle accumulation centres and delineating the scope of the accumulation area.A model for the scheduling of freight trains for the cycle technical station accumulation was designed,and the transport organization methods for daily-delivery direct trains at the loading site,cycle-delivery direct trains at the loading site,and cycle technical station accumulation trains were calculated using the particle swarm algorithm under the conditions of flow constraints,train constraints,and capacity constraints.The results of the case show that the cyclic consolidation of cargo trains can increase the number of direct train services,regularize the flow organization and significantly reduce the transportation costs,which verifies the practicality and feasibility of the model.The method and its model and algorithm can design freight products and services that can meet the transportation demand more efficiently,and provide quantitative calculation methods and decision-making basis for the preparation of railway formation planning and transportation product design in China. |
