Study On Automatic Drawing Of Train Flow Diagram And Relative Problems Of Empty Wagon Distribution

Train flow diagram is a direct graphic form of freight and passenger marshalling plan which shows the path, category and number of train flow in railway network. Train flow diagram is one of the cardinal elements of railway transportation plan and organization and a difficulty in RTCADS. It is also one of the references to add railway technical devices and scheme the locomotive and so on. Train flow diagram has important significance. Empty wagon distribution is precondition of train flow diagram. It is an important element of railway transportation and is also one main makeup of railway freight plan. The paper focuses on the problems of empty wagon distribution in theory and appropriate models are established aimed at the optimal plan of empty wagon distribution, which has important significance to improve the service level of freight transportation and the benefit of railway enterprise, save the transportation costs and the number of minimal wagons, accelerate vehicle turnover and so on.The paper studies on automatic drawing of train flow diagram and empty wagan distribution, plentifully uses former results for reference, combines qualitative analysis with quantitative computing, introduces systematic science, integrates theoretics such as graph theory, mathematical plan, optimization, satisfactory optimization, fuzzy math, database and computer simulation, etc. The chief contents include:I. In allusion to the shortcomings of the current railway train flow diagram plotted by manual work, the paper introduces the component and property of train flow diagram and automatic drawing of train flow diagram. Base on graph theory, the paper discusses the label algorithm of train flow route station, searching algorithm of key vertex in train flow lines, equidistance offset plot algorithm of train flow lines together with vertex aggregate, edge aggregate and legend. We also developed software of the train flow diagram CAD system and used it to automatic draw the passenger and freight train flow diagrams from Liupanshui to Zhanyi for second railway in recent. Practical examples show that automatic drawing of train flow diagram can greatly improve the design efficiency and quality and is in favor of the standardization of train flow diagram. It is certain to be used widely in railway transportation plan and organization department.II. The mathematical model of empty wagon distribution TP is established which aimed at the minimization of consuming wagon-kilometers or trantportation costs. The paper applies table task method, neural network (NN), genetic algorithm (GA), ant colony algorithm (ACO) and LINGO into empty wagon distribution. The result shows that all algorithms above can get the optimal objective value. Both GA and ACO possess multiplicity of resolution and it is obvious that using LINGO to sovle this problem not only saves developing time also has good advantage in both computing time and precision aspects. The paper discusses the problems of empty wagon distribution on large scale railway network and puts forward two-phase optimal method to solve this problem. A model of empty wagon distribution with transition is established to prove that empty wagon distribution with transition in other station can save a lot of wagon-kilometers. Because of the stochastic factors in empty wagon distribution, a stochastic chance constrained programming models is established. The chance constraints can be converted to their respective deterministic equivalents for resolution.III. Because the quantity adjustment and network matching flow are two key issues of empty wagon distribution, integrated optimal model shoule be established. The result shows that indentical path constraint does not correspond with the model, and convection constraint of road segment will not affect the optimal solution of the model. The paper also proposes an evaluation rule for the route chosen rationality connecting O-D pair in railway network and erects the fuzzy function between the overall empty wagon amount and capacity, which is used to test road segment surpassing amount and provide a disposal of the infeasible flow, for the rationality of transportation path.IV. By introducing wagon types, the mathematical model for multi-type empty wagon distribution is described. The paper analyses the effect of substitution of empty wagon types on this model and establishes a mathematical model for the substitution of empty wagon types. The result proves that that the substitution of empty wagon types can improve the benefit of railway enterprise and relieve the pressure of transport capacity. The vehicle adjustment should consider the distribution and flow direction of the loaded and empty wagons. The rational plan of transportation organization can be generated and modeled by integrating the loaded and empty wagons. The result shows that the idea of replacing empty wagons with loaded wagons can greatly reduce the wagon-kilometers. Based on profound analysis of the divivsion of work among marshalling stations in railway network, the paper formulates a new model of cooperative optimization of loaded and empty wagons organization. This model is a mixed non-linear problem of large scale plan and can be solved by using GA.V. The paper analyzes the effect of time efficiency on empty wagon distribution and erects fuzzy subject function based on the relation between customer preference and arrival time of empty wagon distribution. A fuzzy mathematical model of customer preference and a mathematical model with time windows is established at the same time. The simulation result proves that the optimal plan of the above two models are identical despite their motive.At last, the paper applies satisfactory optimization into empty wagon distribution. A satisfactory optimization model is established based on socioeconomic benefit, railway enterprise benefit, customer preference and rationality of transportation path, which is the integration and in-depth research of several factor such as: uncertainty, substitution of empty wagon type, time efficiency, rationality of transportation path, distribution of both loaded and empty wagons, economical benefit. The solution algorithm of satisfactory optimization is also presented. The result shows that the satisfactory optimization is more applicable and effective than the general theoretical optimization. It also puts forward a new idea for the problem of empty wagon distribution.