Energy consumption model for shuttle-based Storage and Retrieval Systems

Automatic warehouses need to balance speed, cost, flexibility, and energy consumption to support the responsiveness, efficiency, and sustainability of modern supply chains. This paper explores environmentally friendly velocity and acceleration configurations of the Shuttle-Based Storage and Retrieval Systems (SBS/RS) under throughput requirement. This study develops an energy consumption model for the SBS/RS with cross shuttles operating on a dual-command-cycle basis and estimates the maximum throughput, travel time and energy consumption. Numerical experiments explore the optimal velocity profiles with the least energy consumption under different throughput requirements. The results show that the lift velocity and acceleration are the leading factors influencing energy consumption. Increasing the accelerations of aisle and cross shuttles can moderately reduce travel times and improve storage efficiency, without hurting energy consumption. Besides, this paper also identifies the relationship between throughput capacity and energy consumption. Overall, this study provides insights on the SBS/RS configurations under given throughput requirements and environmental performance and builds a green decision-making basis for automatic warehouse designers and managers. (C) 2020 Elsevier Ltd. All rights reserved.