【作者】 程文科；

【导师】 胡天军；

【作者基本信息】 北京交通大学 ， 交通运输规划与管理， 2008， 硕士

【摘要】 随着世界经济的发展和科技的进步,物流产业正在世界范围内迅速发展,即使是长期受到学术界和企业界忽视的逆向物流也随着可持续发展理念的深入人心而成为社会日益关注的话题。然而在我国逆向物流的研究还处于初级阶段,尤其是关于带回程取货的逆向物流车辆路径问题(Vehicle Routing Problems withBackhauls,VRPB)的研究远未成熟。VRPB问题是车辆路径问题(Vehicle Routing Problems,VRP)的延伸。VRPB问题不像VRP问题那样只考虑车辆运行中的单纯送货或者单纯取货过程,而是将送货与取货过程结合起来,同时实现送货和取货,更加节省运输成本。如何在逆向物流中经济合适地安排车辆的配送路径成为物流管理者面临的一个重要的问题决策。本文首先介绍了逆向物流的内涵,通过对逆向物流和正向物流车辆路径问题进行比较,指出了逆向物流车辆路径问题的特点。在此基础上,通过对比,指出本文研究的取送交叉VRPB问题和取送无交叉VRPB问题的区别在于放松了取货客户必须在送货客户之后的约束,然后建立无时间窗VRPB问题模型及相关约束。通过对不同算法的比较,最终选择改进遗传算法并进行具体的算法设计,最后以算例进行了验证。本文还针对物流行业的现状,在VRPB问题上增加了节点的服务时间窗限制,建立了带时间窗VRPB问题(Vehicle Routing Problems with Backhauls and TimeWindows,VRPBTW)模型及相关约束并使用最大-最小蚁群算法进行了具体的算法设计。最后通过对示例求得的结果比较,采用本文设计的算法所求结果优于文献结果,从而在实际中更加节省运输成本,实现了VRPBTW问题的优化。更多还原

【Abstract】 With the rapid development of the world economy and modern technology, logistics industry is growing quickly all over the world. The reverse logistics which has been ignored by academia and business circle for a long time is gradually being paid attention to because of the implementing gradually thoroughly of sustainable development strategy. In our country the researches of the reverse logistics, particular in the Vehicle Routing Problems with Backhauls (VRPB) is at the threshold compared with foreign research results.VRPB is the extension of the Vehicle Routing Problems (VRP) which serves only either linehaul customers or backhaul customers. VRPB can serve both linehaul customers and backhaul customers by a fleet of vehicles so that it can reduce the cost of the transportation. How to arrange proper route to cut the cost of logistics operations is a key problem that every logistics manager has to face.Firstly, the paper introduces the definition of the reverse logistics, points the characteristic of the VRP in the reverse logistics through the comparison of the VRP in the logistics and the reverse logistics. On the basis of this, points that the VRPB which is used in this paper doesn’t have the restriction that all backhauls have to be visited after all linehauls as the VRPB which all linehauls and backhauls aren’t mixed. Then the VRPB mathematical model and special constraints are analyzed. The VRPB is solved by the improve Genetic Algorithms (GA) which is chose by the comparison of the different algorithms. Finally, illustration is given through a case study.The paper adds a restriction of time windows on the VRPB on the basis of the reality of logistics industry, and then the Vehicle Routing Problems with Backhauls and Time Windows (VRPBTW) mathematical model and special constraints are analyzed and solved by the Max-Min Ant Colony Algorithms (MMACA). Finally, the results which are solved by the MMACA are better than the traditional algorithms on the example. Therefore, the MMACA can reduce the cost of the transportation in reality so as to realize the optimization of the VRPBTW.更多还原