一种考虑货位共享效应的Fishbone仓储布局优化方法

以Fishbone仓储布局为基础,针对3种经典存储策略,考虑货位共享效应,以单程平均货物拣选距离最短为目标,建立Fishbone布局仓库设计优化模型,以探讨将货位共享效应考虑在内时,不同存储策略对仓储布局的影响;采用分次逼近策略和动态规划算法确定货物的优化分类及类别边界;设计基于自适应的遗传算法获得最优存储分类下的仓储布局参数,并结合案例实验数据进行仿真分析。结果表明,基于分类存储策略的仓储布局表现优异,所需货位数量少且货物拣选距离短;另外,仓储存储物品的需求差异越大,考虑货位共享效应的优势就越显著,最高可减少37.1%的货物拣选距离。     

面向医药行业冷库的移动式货架仓储系统的货位优化研究

为提高移动式货架仓储系统的拣选效率,降低拣选能耗,对其在医药行业冷库应用中的货位优化问题进行研究.针对移动式货架仓储系统自身作业和医药冷库存储的特点,提出以同一巷道品项相关性最大和拣选能耗最小的策略来实现货位优化,建立多目标优化模型.在基本入侵杂草算法(IWO)基础上,设计了混合离散入侵杂草算法(HDIWO)进行仿真求...     

Auto Store仓储系统的运作与效率优化研究

目的 为缓解零售电商商品仓库占地面积广,拣选效率受限等问题。方法 文中就存储策略、指派策略以及路径策略方面对Auto Store仓储系统进行详尽的介绍,在此基础上流程化的分析Auto Store系统完成单次订单拣货作业的业务流程,并运用Anylogic软件对所提出的模型进行仿真和验证。结果 假定订单到达服从Erlang分布,在拣选车和工作站数量和拣选货物数量相同的情况下,对比了Auto Store仓储系统混存布局和传统布局的拣选效率,验证了混存布局的可行性。结论 同时对比基于2种任务指派策略,得出了以基于拣选时间最小化的指派策略下系统运作效率更优这一结论,对理论分析与仿真研究之间的结果进行分析比较,验证了模型的有效性。     

多层棋盘格式立体货架及其货位排布算法研究

为了使立体仓库在更高的空间利用率条件下发挥最大的存取效率和服务能力,对现有立体货架的结构和搬运模式进行了分析,由此提出了一种新型多层立体仓库货架模型,即多层棋盘格式(multilayers chessboard based,MCB)立体货架模型.从二维角度看,MCB立体货架的货位排布方式类似于在矩形棋盘格内摆放棋子问题,针对如何实现MCB排布方式进行了货位排布算法研究,给出了问题描述、数学模型、算法设计,并构建了基于单件多品种随机存储的"棋子算法(chess pieces algorithm,CPA)",对其进行实验验证.实验结果显示"棋子算法"能够合理并有效地解决MCB立体货架的货位排布问题.MCB立体货架能够使单件多品种随机存储立体仓库的空间利用率达到75%以上,并且为实现更高的存储效率奠定基础.     

基于鱼骨型仓库布局的多车拣选路径问题优化

为了推动鱼骨型仓库在实际场景下的应用,针对鱼骨型仓库布局下的拣货路径优化问题,构建待拣货点距离计算模型和以有载重、容积限制的多车拣货距离最短为总目标的拣选路径优化模型。考虑遗传算法(GA)全局搜索能力强、粒子群算法(GAPSO)收敛速度快以及蚁群算法(ACO)较强的局部寻优能力,提出一种解决拣选路径优化模型的混合算法(GA-PSO-ACO)。通过不同订单规模的仿真实验,得出该混合算法在适应度值、迭代次数、收敛速度等方面均优于GA算法和GAPSO算法,且在订单规模较大时,平均适应度值约降低8%,有效缩短了总拣选距离,验证了混合算法在解决鱼骨型仓库布局下的拣货路径问题的先进性和有效性,为解决此类仓库内部的拣货路径问题提供新的解决方法和思路。     

三维紧致化存储系统中出入口位置的优化研究

目的解决三维紧凑型存储系统的设计问题,寻求系统出入口的最佳位置。方法建立数学模型,并优化求解,研究自动化仓储系统出入口位置的设计问题。结果在双命令存储模式下,当三维紧致化仓储系统的系统出入口位置在货架底端1/2位置时,双命令行程期望时间最少。结论通过假设出入口的位置,列出共计24种双命令下存取货物的期望时间模型,并进行了求导分析,发现在双命令存储模式下系统出入口最优点即为货架底端中点处。     

基于二进制粒群的拣选作业优化

目的提高电子标签拣选系统中拣选作业的效率与货位占有率。方法以某电子拣选库为研究对象,提出以订单完成度、货位占有率以及货位聚集度为目标的拣选优化模型。设计基于二进制粒子群算法(BPSO)和遗传算法(GA)的模型求解仿生算法。结果试验及优化结果表明,基于BPSO的电子拣选库订单的完成度、货位占有率以及货位聚集度较遗传算法更高。结论基于二进制粒子群算法求解的优化模型较符合实际的电子拣选库人工拣选作业,同时仓储作业货位的利用率及拣选效率得到了提高。     

三维紧致化存储系统中货架尺寸的优化研究

目的当存储系统出入口位于货架底端中点位置并采取双命令周期存储模式时,对系统尺寸进行设计,以使仓储的空间得到最大化利用。方法建立三维紧致化存储系统双命令周期行程时间数学模型,假设系统出入口位于货架底端的位置,分6种情形展开讨论,研究自动化仓储系统出入口位置的设计问题。结果通过模型优化求解,确定选择类型5(使a*=1.1,b*=0.63),系统的长高宽比例为1.1∶0.71∶1.2时,堆垛机运行效率最高。结论通过仿真得出,当三维紧致化存储系统中货架尺寸长高宽比例为1.1∶0.71∶1.2时,双命令周期下的系统期望行程时间最小,即三维紧致化存储系统在该比例下执行双命令存取操作,耗时最短。     

SV波斜入射下河谷地形地震动分布特征分析

基于黏弹性边界结合等效荷载的输入方法,实现了平面SV波斜入射的地震动输入。研究了SV波入射角度和河谷斜坡坡度对河谷场地地震动放大系数分布特征的影响。结果表明:地震波入射角度和斜坡坡度越大,斜坡坡面以及坡顶平台一定范围内的地震动放大系数越大,坡顶平台的影响宽度也越大;地震波从左侧倾斜入射时,河谷两岸地震动放大系数呈不对称形式分布,且入射角度越大,河谷左岸x分量的地震动放大系数越大,河谷右岸z分量的地震动放大系数越大,不对称现象越明显;以不同角度入射时,坡顶处地震动放大系数和坡顶平台影响区域均随坡度的增大呈线性增大趋势;入射角度与斜坡坡度越大,坡顶处水平加速度反应谱越大,反应谱峰值有向右偏移的趋势。     

不同宽度及放置角度下聚甲基丙烯酸甲酯的燃烧传热特性

研究了宽度分别为2 cm、3 cm、5 cm和8 cm的聚甲基丙烯酸甲酯(PMMA)在放置角度为0°、15°、30°和45°的情况下燃烧传热特性。通过图像分析、红外热像、热电偶测温等技术对火焰形态及燃烧特性参数(火蔓延速度、火焰倾角、火焰高度以及火焰温度等)进行了表征。研究发现,有机玻璃燃烧过程中,热解前锋呈现出U型的特点,宽度越大,其U型演变时间越长。放置角度越大时,火蔓延速度对宽度的敏感性越大,即宽度越大火蔓延速度越大。这主要由于,随着宽度和放置角度的增加,火焰倾角变得越来越小,火焰与材料表面更加贴近,从而促进热量的传递。研究同样发现,在相同放置角度下,平均火蔓延速度受平均火焰高度以及上下波动程度的影响;火焰温度基本上不受宽度影响等特点。     

Optimal layout in low-level picker-to-part systems

The paper presents an analytical approach to layout design of the picking area in low-level, picker-to-part systems using COI (cube per order index)-based and random storage policies. The layout of the picking area is one of the major issues in increasing picking system productivity, i.e. in reducing the time required to complete a given set of orders, and must take account of the inter-relationship between the main operating policies, i.e. storage, routing and batching. The main system parameters affecting the layout design are the total length of the picking aisles, the number of pick stops per tour and the shape of the COI-based ABC curve. A formula that relates the optimal number of aisles to the above parameters will be presented, together with the increase in the expected tour distance stemming from the adoption of a non-optimal number of aisles. The study thus provides a comprehensive framework for layout design.     

面向仓库货架的商品智能拣选机器人设计

目的 为降低仓储拣选作业的劳动强度、提高拣选准确率,设计一款可代替人工拣货的拣选机器人。方法 基于PaddlePaddle的PP-ShiTu图像识别系统,实现货架商品的精确识别和种类的快速更新;针对低成本机械臂的视觉抓取问题,提出基于“无标定3D视觉+AGV运动控制”的货架商品抓取引导方法;采用二维码自主导航和智能升降系统实现了货架商品的搬运和立体抓取。结果 实验证明,所设计的拣选机器人实现了货架商品的精确抓取和搬运,测试准确率达到了92.25%。结论 基于该方法构建的智能拣选机器人,可以完成仓库货架商品的拣选和搬运。     

Analytical models for pick distances in fishbone warehouse based on exact distance contour

The pick distance models for a unit load warehouse employing fishbone layout conventionally use semicircular approximation for distance contour which can result in significant error. This paper develops discrete and continuous pick distance models for fishbone layout under random, full turnover, and class-based storage policies based on exact polygonal distance contour. Class-based storage policy with three classes was found to give pick distance comparable to full turnover policy over a range of demand skews and warehouse shapes studied. The discrete and continuous models are compared considering finite storage space, aisle width and discontinues in the ABC curve for a real life data. The sensitivity of warehouse performance over a range of warehouse parameters is studied. We also outline a methodology for class-based storage design where class partitions can be derived for a warehouse of any dimension from the results of a unit area warehouse.     

An integrated storage assignment method for manual order picking warehouses considering cost,workload and posture

This paper presents an integrated storage assignment method for low-level picker-to-parts order picking warehouses taking into account economic and ergonomic objectives. Three different pallet rack layouts are studied in this paper, namely (a) picking from full pallets on the floor, (b) picking from half-pallets on the floor, and (c) picking from half-pallets on the upper rank of the shelf. First, cost functions are developed to assess the total order picking performance impact of these different pallet rack layouts. Second, with regard to workload, the metabolic cost and energy expenditure rates for picking from the different rack layouts under study are derived. Third, for assessing the working posture during order picking, the Ovako Working Posture Analysing System index is used where the required data is collected using a motion capturing system. The developed models are combined to propose a heuristic storage assignment procedure that supports the decision of which item to store on which pallet. The developed storage assignment method is then applied to an industrial case study. The results of the paper support warehouse managers in assessing the order picking storage assignment from an ergonomics viewpoint and in estimating its impact on financial order picking performance.     

Research on Cell Manufacturing Facility Layout Problem Based on Improved NSGA-II

With the rapid development of the individualized demand market, the demand for manufacturing flexibility has increased over time. As a result, a cell manufacturing system suitable for many varieties and small batches has been produced. With the goal of minimizing the area and logistics handling volume, and considering the arrangement order of facilities and channel constraints, a mathematical model was established, and the problem was solved by improved NSGA-II. After non-dominated sorting, traditional NSGA-II will cross-operate the individuals with the best sorting to generate new individuals. Such a selection strategy is extremely easy to fall into the local optimal solution. The improved NSGA-II is to improve the original selection operation, which is to select the first half of the excellent individuals in the non-dominated sorting into the cross operation, and then select the last sorted ones of the remaining individuals into the cross operation, and combine the best and the worst ones into the cross operation. Finally, an example is given to simulate and improve the solution of NSGA-II and NSGA-II. The simulation results indicate that the improved NSGA-II population shows more obvious diversity, it is easier to jump out of the local optimal solution than NSGA-II, and the satisfactory layout scheme of manufacturing cells is obtained. Therefore, it is more effective to use improved NSGA-II to solve the problem of manufacturing cell layout.     

A model for warehouse layout

This paper describes an approach to determine a layout for the order picking area in warehouses, so that the average travel distance for the order pickers is minimized. We give analytical formulas that can be used to calculate the average length of an order picking route under two different routing policies. The optimal layout can be determined by using these formulas as the objective function in a nonlinear programming model. The optimal number of aisles in an order picking area appears to depend strongly on the required storage space and the pick list size.     

Storage policies and order picking strategies in U-shaped order-picking systems with a movable base

Prior research on storage policies and order-picking strategies in order-picking systems has concentrated on studying warehouses with parallel shelves that are separated by horizontal and/or vertical aisles. This paper analyses a special case of an order-picking system where the warehouse is divided into zones with shelves being arranged in the shape of a U in each of the zones. The paper assumes that the shelves of the order-picking system are made up of two rows of stillages that can be flexibly exchanged and that the base of the order-picking process can be moved within the aisle prior to the beginning of the order-picking process. We describe the order-picking system in a formal model and propose different storage location assignment policies whose efficiency is compared in a numerical study. The paper pays special attention to the practical applicability of the model and proposes heuristics that can be easily implemented in practice.     

基于Plant Simulation的航空综合机加厂房布局仿真研究

科学的生产设置布局规划对航空制造业降低生产成本、提高产品质量尤为重要.以某民用航空发动机传动系统的齿轮和机匣综合加工厂房的规划设计为例,根据厂房设施布置的一般原则,以齿轮和机匣的年产量目标、产品加工工艺、单工艺加工面积需求为设计输入,并考虑各加工区的加工特点而带来的位置约束性,采用遗传算法与模拟退火算法相结合的混合遗传算法为优化工具,将特定的功能区固化在基因串特定的位置上来满足位置约束．计算得出优化方案后,以Plant Simulation为仿真平台,建立该综合机加厂房的仿真模型,从产量满足率、设备利用率、在制品库存量和生产线稳健性等多个指标进行了设施布局的仿真评价．结果表明,优化后的系统能够很好满足生产纲领,各关键设备负载比较均衡,同时维持低水平的在制品库存量,且生产线稳健性较好．因此,综合运用混合遗传算法与Plant Simulation仿真可以为生产设施布局问题给出一种有效、直观的解决方案,且由离散事件仿真获取的评价指标能深刻体现方案的优劣．     

新型无人仓AutoStore的货物合箱方法研究

目的 为减少AutoStore系统在共同存储策略下的订单处理时间,解决经营品类繁多,但仓储面积有限的企业货物存储问题。方法 提出货物合箱的存储方法,设计关联规则挖掘算法与混沌种子优化算法的混合优化算法进行求解。从机器人翻箱操作、料箱的分配规则、系统布局三方面进行分析,结合AutoStore运作规律,建立以机器人拣货行走距离最短为目标函数的数学模型,通过Apriori算法输出货物热度,输入混沌种子算法,得到储位分配结果,实现联动决策。在基本种子算法的迭代中加入混沌序列,帮助种子避开局部极小值。结果 实例分析表明,货物合箱方法能够显著减少共同存储下AutoStore系统的订单处理时间,缩小与指定存储策略订单处理时间的差距,与粒子群算法和基本种子优化算法相比,混沌种子优化算法的优化效率更高、稳定性更好。结论 文中的研究为经营品类繁多,但仓储面积有限的企业提供了一种更适合的货物存储策略,具有较强的操作性和实际意义。