Concurrent Optimization of Shared Location Assignment and Storage/Retrieval Scheduling in Multi-Shuttle Automated Storage and Retrieval Systems

摘要

Multi-shuttle automated storage/retrieval systems differ from automated storage/retrieval systems in that they carry more than one load at a time and are able to perform storage immediately after retrieval at the same location in a storage rack. These capabilities contribute to increased throughput and capacity utilization and reduced storage and retrieval time. We address concurrent storage location assignment and storage and retrieval sequence scheduling under the shared storage policy and the modified 2n-command cycle pattern. Owing the problem complexity to large-scale instances, a hybrid solution procedure that combines an Ant colony algorithm and Adaptive Large Neighborhood Search is proposed. In addition, a mathematical model, based on the allocation problem, is proposed to improve the quality of the solutions.