Storage Systems with Virtual Aisles

在自动化和传统的人工仓库中，在系统的存储密度(每平方英尺或立方英尺的物品)和该系统的吞吐量(每单位时间检索的物品)之间存在典型的权衡。存储越密集，吞吐量就越低。这项研究提出了一种新的存储系统设计，它可以提供非常高的存储密度和非常高的吞吐量，使用了一个被称为“虚拟通道”的概念。将为该系统开发一个概念模型，包括管理同时检索多个物品的分散控制算法。第二种算法将整合物品的补充，使系统能够在稳定状态下运行。将探索多个目标，包括控制系统以最大化吞吐量和控制系统以最大限度地减少能源消耗。研究的第二阶段探索如何在存储系统中分配空闲空间，从而最大限度地缩短检索项目的预期时间。最后阶段将开发控制算法，允许从所有四个方面插入和取出物品，使其在三维上成为一种“活立方体”，允许物品根据命令进出。如果拟议的控制算法在吞吐量和存储密度方面提供承诺的好处，使用它们的系统可以显著减少任何使用自动化材料处理技术的工厂和仓库的内部存储占用空间。这些算法将成为分散控制的存储系统的一部分，这将允许在现代制造和分销中更灵活、更强大的材料处理。本研究所采用的分析方法(元胞自动机的统计分析)也将导致物流系统分析和设计的新工具的发展。

In automated and traditional manual warehouses, there is a classic tradeoff between the storage density of the system (items per square or cubic foot) and the throughput of that system (items retrieved per unit time). The more dense the storage, the lower the throughput. This research proposes a new storage system design which could provide both very high storage density and very high throughput, using a concept called "virtual aisles." A conceptual model for this system will be developed, including a decentralized control algorithm that manages the simultaneous retrieval of multiple items. A second algorithm will integrate replenishment of items, allowing the system to operate in steady-state. Multiple objectives will be explored, including controlling the system to maximize throughput and controlling it to minimize energy consumed. The second phase of the research explores the allocation of free, or empty, space within the storage system, in a way that minimizes the expected time to retrieve an item. The final phase will develop control algorithms to permit insertion and extraction of items from all four sides, making, in three dimensions, a sort of "living cube," which allows items to pass in and out upon command.If the proposed control algorithms provide the promised benefits in terms of throughput and storage density, systems that use them could significantly reduce the footprint of internal storage in factories and warehouses of any industry using automated material handling technology. These algorithms would be part of storage systems with decentralized control, which could allow for more flexible and robust material handling in modern manufacturing and distribution. The analytical methods employed in this research (statistical analysis of cellular automata) will also lead to the development of new tools for material handling systems analysis and design.