Optimization Of Locomotive Assignment And Routing Train Trough A Railway Passenger Station

Railway passenger station is the basic unit of railway passenger transportation. As train diagram is determined, trains'arrival-depart time and operations in railway passenger station are decided. Based on equipment occupancy compatibility, how to assign train operations to occupy equipments in efficient and reasonable way is the goal of train operation organization in railway passenger station.There are three key problems in train operation organization:optimization route assignment, arrival-departure track assignment and locomotive assignment. The above three problems influence and constrain each other, which lead to the limitation of optimizing one of them separately, so it is necessary to optimize the three problems comprehensively.Firstly, the comprehensive optimization of arrival-departure track, inbound and outbound route assignment was discussed. Notice that arrival-departure track is part of inbound and outbound route. So the arrival-departure track occupied by train is determined by inbound and outbound route. According to this point, considering the coordination of train diagram, arrival-departure track, inbound and outbound route assignment, taking inbound and outbound route as decision, arrival-departure track and switch occupancy compatibility as constraint, on the base of assigning arrival-departure track, inbound and outbound route for relatively important trains as possible, taking arrival-departure track utility maximization as optimization objective, the comprehensive optimization model of arrival-departure track, inbound and outbound route assignment in a throat of railway passenger station was established. With the thought of maximal feasible solution, the concepts of maximal train route plan and its k rejection neighborhood were proposed, according to the concepts, the simulation annealing algorithm to this model was designed. This algorithm only searches maximal train route plan, which greatly reduces the solutions that need to be searched and improves the efficiency of algorithm.Secondly, the problem of routing train through a railway passenger station was discussed. The train route though a passenger station is composed of inbound route, arrival-departure track and outbound route. Because inbound and outbound route determine the arrival-departure track occupied by train, inbound and outbound route determine train route through a railway station. According to this point, considering the coordination of train diagram and routing train through a railway station, taking train route through a railway station as decision, arrival-departure track and switch occupancy compatibility as constraint, on the base of assigning train route through a railway station for relatively important trains as possible, considering arrival-departure track and route utility maximization as optimization objective, the optimization model of routing train through a railway station was established. With the thought of maximal train route plan, the concepts of maximal train route though a railway station plan and its k rejection neighborhood were proposed, according to the concepts, the simulation annealing algorithm to this model was put forward.Finally, the comprehensive optimization problem of locomotive assignment and routing train through a railway passenger station was discussed. On the condition of the time of couches into and out from couch yard are known, the locomotive assignment optimization problem with the goal of minimizing the locomotive number and running mileage can be described by a locomotive sending and fetching coaches assignment problem with the goal of minimizing locomotive sending and fetching coach connect time and mileage. Taking coach route out from coach yard as the inbound route of origination train, coach route into coach yard as the outbound route of destination train, the train route through a railway station was expanded. Based on these, considering the time of coach into and out from yard and train route through a railway station as decision, with combination of the optimization model of routing train through a railway station and the assignment model of locomotive sending and fetching coach, the comprehensive optimization model of locomotive assignment and routing train through a railway passenger station was established, the simulation annealing algorithm to this model was designed. And at last, the comprehensive optimization of operation route assignment, arrival-departure track and locomotive assignment of railway passenger station was achieved.