The Study On Models And Algorithms About Operations Of Placing-In And Taking-Out Of Wagons With Railway Tree-Shaped Special Lines

The operations of placing-in and take-out of wagons is an indispensable link in the production of railway freight traffic and the system of placing-in and take-out of wagons plays a very important role in the daily organization of railway technical station operation as a key part of station dispatching system. Arranging the operations of placing-in and take-out of wagons in scientific and reasonable and optimizing the operating organization has a direct significance in improving transport efficiency and economic efficiency. For this, the domestic and overseas scholars make much extensive and in-depth research in the two aspects of modeling and methodology. Every method has its advantages and disadvantages, also has its limitation and obstacle on application. There are important research subjects that how to effectively make full use of these methods to solve the actual problems, and how to make it service the practical operational system for placing-in and take-out of wagons.It is introduced that the research background, significance, the research status at home and abroad, and the problem existed in the current research fields in the problem of placing-in and take-out of wagons. And then the concept of railway special lines, the concept of the problem of placing-in and take-out of wagons, and its principle, mode, and classification are elaborated. Through the contrast between railway tree-shaped special lines and radial special lines in shape features and the method for placing-in and take-out of wagons, the main research content is raised of this paper that the research of problem of placing-in and take-out of wagons with the tree-shaped special line of railway.In the next, the dissertation directing at the operations of placing-in and take-out of wagons with the tree-shaped special line of railway, considering the total locomotive travel time for placing-in and take-out and the total number of train hours as the two optimization goals, build the mathematics model in the six kinds of modes respectively of single for placing-in of wagons, single for take-out of wagons, the combination for placing-in and take-out of wagons, placing-in of wagons with move, take-out of wagons with move, and the combination for placing-in and take-out of wagons with move. Then based on the models it designs the algorithms for the problem of placing-in and take-out of wagons in each mode of two optimization goals using Genetic Algorithms and Ant Colony Algorithms respective. It also designs the example which concludes 10 special line nodes to each mathematics model and solve the examples with two algorithms. By the solutions of solving examples, the solving efficiency and the advantages and disadvantages of solutions is analyzed.In addition, the dissertation have a preliminary research in the problem of placing-in and take-out of wagons in the tree-shaped special lines with multi-locomotive, considering the total kilometer numbers of locomotive travel as the optimization goal to build the mathematics model for the multi- locomotive problem in the mode of single for placing-in of wagons and solve the example which conclude 15 special line nodes using Genetic Algorithms to verify the feasibility of the model.Finally, the paper summarize the whole problems of placing-in and take-out of wagons in the tree-shaped special line and analyze the factors without considering in solving problem and the deficiency of the model in addition to prospecting the parts of the paper which are improved.