An Item Retrieval Algorithm in Flexible High-Density Puzzle Storage Systems

Abstract

This paper studies a design of a puzzle-based storage system. We developed an item retrieval algorithm for our system which has three advantages over the previous counterparts in the literature: (i) we can retrieve items from all sides of our storage system; (ii) the existence of only one empty cell in our system is sufficient to retrieve an item; and (iii) our algorithm never ends in deadlocks. The main feature of our algorithm is to prefer three moves to five moves in the process of moving the seized empty cell toward the optimal side of the requested item. The conventional view in the literature assumes that increasing the number of empty cells always reduces the number of movements required for retrieving items; however, our simulation results show that depending on the size of the puzzle and the number of the requested items, increasing empty cells might make the retrieval process more complicated.