A new truck based order picking model for automated storage and retrieval system (AS/RS)

Abstract

This paper examines a single-direction, high density, deep-lane warehouse and develops a truck based, one-cycle order picking automated storage and retrieval system (AS/RS) that minimizes either travel time or energy consumption. The warehouse is considered completely full at the beginning of the picking task, and the alignment of the trucks at the output station is known before they arrive. The time and energy based algorithm assigns the best cell address of the product pallet and optimum shuttle robot according to the truck order picking instructions. Unlike previous studies, this study focuses on a reserved storage part in the warehouse for orders of trucks and defines overall aisle and shuttle robot components. Different from most algorithms, the algorithm used in this study identifies not only the minimum travel time route, but also the least energy consuming route as two different cases. The order picking task with the reserved storage area as the destination is formulated as an analytical problem. Energy and time based order picking period simulation results are compared, and real applications in the warehouse of the project partner firm are discussed.