遗传算法在多式联运路径优化的应用

发布时间：2018-11-01 15:33

【摘要】：多式联运在我国是指通过转运衔接两种以上的运输方式,从而将货物从出发点送到目的地的过程。通过使用多式联运,可以充分利用各种运输方式的优点和避过不足之处,实现运输时间与空间上的无缝衔接。多式联运的路径优化上不只是要考虑时间和成本,还要考虑前后运输方式的衔接,风险和转运的损耗,运输的质量,服务水平等。而不同运输方式的这些指标都不相同,由此可见,多式联运是个十分复杂的系统。本文对带时间窗的多式联运模型进行研究,引出运输班次对运输时间的影响,建立以运输班次为参变量的的多式联运优化模型,并使用基于Pareto最优的遗传算法对模型的多个目标进行同时求解。研究具体内容如下:(1)分析我国多式联运发展现状与国内外研究状况,归纳整理相关文献,将研究方向分为对运行管理的研究与网络货流规划的研究。其中网络货流规划包含了路径的优化与运输方式的组合。本文研究讨论的正是网络货流规划。通过研究找出符合我国国情的多式联运研究方向与应采用的策略。(2)以成本最低,时间最少与碳排放最小为目标建立多式联运模型,模型考虑时间因素,建立时间窗,对提前与延期到达目标节点都做惩罚。然后考虑每个节点运输方式的限制,加入备选集作为约束条件,并根据班次设置等待时间。(3)通过基于Pareto最优的遗传算法,设置模型具体的运算步骤。并将数据带入,逐步求解,并与单纯使用时间窗的模型做对比。通过修改模型中货物的出发时间,研究它对结果的影响。
[Abstract]:Multimodal transport in our country refers to the process of connecting two or more modes of transport through transshipment, so as to deliver the goods from the starting point to the destination. By using multimodal transport, the advantages and disadvantages of various modes of transport can be fully utilized, and the seamless connection between transport time and space can be realized. The route optimization of multimodal transport should not only consider time and cost, but also consider the connection of transportation mode, the risk and loss of transshipment, the quality of transportation, the level of service and so on. These indexes of different modes of transport are different, so multimodal transport is a very complex system. In this paper, the model of multimodal transport with time window is studied, and the influence of transportation frequency on transport time is introduced. The optimization model of multimodal transport with transportation frequency as parameter is established. A genetic algorithm based on Pareto optimization is used to solve multiple objectives of the model simultaneously. The research contents are as follows: (1) analyze the development of multimodal transport in China and domestic and foreign research status, summarize and sort out the relevant literature, the research direction is divided into the operation management research and the network cargo flow planning research. The network cargo flow planning includes the combination of route optimization and transportation mode. This paper studies and discusses the network cargo flow planning. Through the research to find out the research direction and the strategy that should be adopted in the multimodal transport according to the situation of our country. (2) taking the lowest cost, the minimum time and the minimum carbon emission as the goal to establish the multimodal transport model, the model considers the time factor, establishes the time window, Punish both early and late arrival at the target node. Then considering the limitation of each node's transportation mode, the alternative set is added as the constraint condition, and the waiting time is set according to the shift. (3) the concrete operation steps of the model are set by genetic algorithm based on Pareto. The data are brought in, solved step by step, and compared with the model using only time window. By modifying the departure time of the goods in the model, the effect of the model on the result is studied.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP18;F512.4

【参考文献】