The Modle And Algorithm Of Train Path Connection Based On Wagon-Flow Allocation Of Technical Station

Train diagram regulates the order in which a train occupies a section, the time at which a train arrives and departs at the station, together with the operation time at section, dwell time at station, therefore, Train diagram is the technical document for train operations, and the basis of train railway organizations. When train paths adjacent to the technical station are determined, the train number allocation is one of the most important aspects of computerized train diagram. Previously, from the point of view of the equilibrium of trains, the research didn’t take account of transfer cars connection resulting in the longer dwell time of transfer cars at the technical station. In order to coordinate train diagram with train formation plan, combine car flow with train path at the greatest degree, train number allocation must optimize car flow connection. Based on research wagon-flow allocation at the technical station at home and abroad, the dissertation studies train path connection, builds the mathematical models of related problems, seeking the effective algorithms combined with operational research,combinatorial mathematics and intelligence algorithm.The main research of the dissertation is as follows:1. By introducing procedure of train working diagram, and analyzing operation process of through trains, arriving train and departing train at technical station, the connection time standard of through train and transit car has been obtained, which lays the foundation for optimization of through trains connection and train number allocation.2. According to through train’s connection time standard and the period of train path at technical station, mathematical model aiming at the minimum dwell time of through trains is set up. The problem is converted into a network flow model added into a source and a sink, solved by minimum cost flow algorithm. Finally, the optimal scheme of selecting arrival and departure path of through trains is obtained.3. Taking account of the combination of car-flows, railway line and departure train category equilibrium. Based on the time of departure train path and train formation plan, the mathematical model of departure train number allocation at technical station, with the aims of the minimum dwell time of transit cars, train category equilibrium and the minimum train intensity, is set up. Multi-objective ant colony algorithm is designed, which ants construct corrent noninferior solutions each iteration and renew the quantity of pheromone of the path belonging to noninferior solutions, noninferior solutions which are near to pareto optimal solution will be found. 4. In the process of freight train diagram compilation, it is designed to make a balanced layout of arrival and departure trains of various directions, with the purpose to avoid the intensive arrival and departure for trains of the same kinds at the technical station. For the technical station where the train number of inbound and departure path have not been determined, the problem of train number allocation of inbound and departure path should be solved after train path has been drawn up. Based on the time of inbound and departure train path, inbound car flow and train formation plan, the mathematical model of train number allocation at technical station, with the aims of the minimum dwell time of transit cars and train category equilibrium, is set up. According to the characteristics of multi-objective optimization model, firstly the minimum dwell time of transit cars is obtained by the proposed heuristic algorithm, secondly train category equilibrium is improved by adjustment strategy, finally the noninferior solutions of advantageous exchange set are the optimal solution.