An order picking algorithm for vertically stacked and top-retrieval storage systems

초록

Automated and robotic warehouses are becoming more common in the logistics industry. This study considers a variant of autonomous vehicle based storage and retrieval (AVS/R) system in which a transfer robot stores and retrieves vertically stacked bins on top of a grid of stacks. This system maximizes space utilization while spending waste time for removing upper bins if a retrived bin is stored deeply down in a stack. Such a process is called reshuffling. This study proposes an algorithm to determine a sequence of picking orders that minimizes reshuffling. Instead of finding the optimal sequence among exponentially many sequences, this study proposes an efficient greedy algorithm that achieves a heuristic solution. In the numerical study, the best solution was 12.7σ better than the random sequence average; it outperforms most arbitrary sequences. © 2021 ICIC International. All rights reserved.

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