Optimization of a High Storage System with two Cranes per Aisle

Automated storage and retrieval systems (ASRS) are important in distribution centers and warehouses. To decrease cost or CO2 emissions it is natural to optimize various aspects of an ASRS. In this work, we provide a concept for a two-phase optimization combining two important optimization tasks in ASRS: Given multiple rearrangement jobs, we first sequence these jobs to minimize the total travelling distance of the cranes. We continue the optimization by computing optimal trajectories for the sequence to guarantee energy efficient driving of the cranes. We describe our algorithms for a complex ASRS architecture with two cranes on parallel rails in one aisle. Additionally, we describe how to use our results for parallelization of crane movements in the considered warehouse architecture.