论文标题
在带有多个访问说明的块堆叠存储系统中求解单位负载预摩尔歇尔问题
Solving the unit-load pre-marshalling problem in block stacking storage systems with multiple access directions
论文作者
论文摘要
块堆叠存储系统是高度适应性的仓库系统，投资成本低。通过多个深层车道，它们可以达到高存储密度，但是访问某些单位负载可能会很耗时。单位负载预磨影问题分类单位在非高峰时间段中的块堆叠存储系统中加载，以准备即将到来的订单。目的是根据每个单位负载的检索优先级组，找到以升序顺序对存储舱进行测序所需的最小数量的单位载荷移动。在本文中，我们提出了两种解决方案方法，用于确定最小单位载荷数量。我们表明，对于具有一个访问方向的存储托架，可以从容器预摩尔沙尔问题中调整现有的最佳树搜索过程和下限启发式方法。对于多个访问方向，我们基于网络流模型和A*算法开发了一种新颖的两步解决方案方法，具有适用于所有情况的适用下限的A*算法。我们进一步分析了在计算实验中为随机生成的问题实例中提出的解决方案的性能，并表明多个访问说明大大减少了单位负载的总访问时间和所需的分类工作。
Block stacking storage systems are highly adaptable warehouse systems with low investment costs. With multiple, deep lanes they can achieve high storage densities, but accessing some unit loads can be time-consuming. The unit-load pre-marshalling problem sorts the unit loads in a block stacking storage system in off-peak time periods to prepare for upcoming orders. The goal is to find a minimum number of unit-load moves needed to sequence a storage bay in ascending order based on the retrieval priority group of each unit load. In this paper, we present two solution approaches for determining the minimum number of unit-load moves. We show that for storage bays with one access direction, it is possible to adapt existing, optimal tree search procedures and lower bound heuristics from the container pre-marshalling problem. For multiple access directions, we develop a novel, two-step solution approach based on a network flow model and an A* algorithm with an adapted lower bound that is applicable in all scenarios. We further analyze the performance of the presented solutions in computational experiments for randomly generated problem instances and show that multiple access directions greatly reduce both the total access time of unit loads and the required sorting effort.
