Research Of The Fetching And Delivering Wagons Optimization Methods In Metallurgical Enterprise

Railway transportation carries the supplies and ensures the production. The quality and efficiency of metallurgical enterprise’s railway shunting plan has great influence to transportation efficiency and production costs. Compared with the state-owned railway freight transportation, railway transportation in metallurgical enterprises has the following characteristics:it has less receiving departure operation and more shunting operation like marshalling and fetching-delivering; its marshalling and fetching-delivering process connected closely; it accomplish transportation tasks by both state owned and enterprise owned freight train. Using existing state-owned railway shunting scheme is difficult to suit directly to enterprises’ railway transportation demand.A variety of published literature generally aim at minimize locomotive running time in enterprises. However, this goal does not reflect the difference between enterprises owned freight train and state-owned freight train, that is, it ignores the increasing operation cost caused by state-owned freight train over-stayed in enterprise. This thesis considers with the characteristics of enterprise railway transportation scheduling, aiming at reduce the residence time of state-owned freight train in enterprises as the overall optimization objective, researched the optimization of railway transportation scheduling issue in metallurgical enterprises. Research work in this thesis is focused on the following:First of all, through analyzing enterprises railway transportation process, the overall optimization problem was broke up into three sub optimization problems:marshalling optimization, fetching-delivering optimization and route selection optimization. The optimization goal of each optimization problem and their relationship between all the optimization problems was researched. Based on that, the fetching-delivering problem was further studied, which has the greatest impact on the order of production of all shunting operations because it has the longest time and mileage.Second, factors affecting enterprises’fetching-delivering pattern was analyzed. The enterprises’ fetching-delivering problem was summed up to vehicle routing problem (VRP). Compared correlation model of vehicle routing problem, difference between enterprises’ fetching-delivering problem and existing VRP models was analyzed. Based on that, considering that a locomotive works for a certain region, aiming at minimize state-owned freight train occupancy time, a multi-drive and single locomotive traveling salesman problem with capacity and mixed time window model (C-TSPMTMTW) was established.Finally, in order to verify the effectiveness of the model presented in this thesis, simulation software was designed to solve fetching-delivering optimization problem, genetic algorithm was improved, and verification test was achieved.Compared to the optimization goal of minimize the locomotive running time, optimal scheduling strategy proposed in this thesis can save a great deal of time and cost, which indicates the effectiveness of the model and algorithm proposed in this thesis.