Abstract: Aiming at the situation of selecting different batches of orders might require the same Stock Keeping Unit (SKU) bins in Autonomous Vehicle Storage and Retrieval System (AVS/RS),the order batching problem of SKU bins buffer was studied.Considering the quantity of SKU in each order,the quantity of SKU stored in each bin and the capacity of bin's buffer area,a mixed integer programming model for joint optimization problem of orders batching and picking was established by taking the strategies of orders batching,batches sorting and bins delivering as decision variables,the  minimum total number of SKU bins as the goal.The joint optimization problem was decomposed into three sub-problems:order batching problem,SKU bins transporting problem and batches sequencing problem,and a three-stage heuristic algorithm was designed to solve the problems.The effectiveness and rapidity of this three-stage heuristic algorithm were verified by the simulations on different scale examples.By analyzing the influence of picking station capacity and bin buffer area on the optimal solution,the result showed that the total number of SKU bins to be transported was reduced with increasing the either parameter.For the given set of orders to be picked,the number of bins reduction for each unit of additional capacity was to be smaller with the increasing of SKU bins buffer area capacity.The superiority of setting SKU bins buffer area was verified by comparing the strategies of order batching and picking with and without SKU bins buffer area.

Key words: stock keeping unit bins buffer, autonomous vehicle storage and retrieval system, order batching, sequencing, stock keeping unit bins delivering, heuristic algorithm

摘要： 针对自动小车存储及取货系统(AVS/RS)中拣选不同批次订单可能需要出库同一货箱的情况,研究了设置货箱缓存区的订单分批拣选问题。在考虑订单中商品订购数量、货箱中商品存储量,以及货箱缓存区容量的情况下,以订单分批、批次排序、货箱出入库为决策变量,以最小化货箱出库总次数为目标,建立了订单分批拣选联合优化问题的混合整数规划模型。进一步将联合优化问题分解成3个子问题:订单分批问题、货箱出库问题、批次排序问题,并设计了求解模型的三阶段启发式算法。利用不同规模的算例进行模拟计算,验证了三阶段启发式算法的有效性和快速性。通过分析拣选台容量和货箱缓存区容量变化对求解结果的影响,发现增大拣选台容量或货箱缓存区容量均可以降低货箱出库总次数。对于给定的待拣选订单,随着货箱缓存区容量的增大,每增加一个单位货箱缓存区容量所带来的出库货箱次数降低量越来越小。最后通过对比分析设置货箱缓存区和不设置货箱缓存区情况下的订单分批拣选策略,验证了设置货箱缓存区的优越性。

关键词: 货箱缓存区, 自动小车存储及取货系统, 订单分批, 排序, 货箱出库, 启发式算法