Predictive Decision Models for an Energy Efficient Operation of Stacker Cranes in a High-Bay Warehouse

This paper presents a simulation-based optimization framework to find and evaluate optimal storage plans in a high-bay warehouse. The two objectives under consideration are reducing the total energy consumption and maximizing the recuperation of energy of stacker cranes. These cranes operating in different aisles are connected by an internal circuit. One part of the framework simulates the power flows both on a single stacker crane and in the internal circuit. Based on that, the optimization part computes energy optimal trajectories for prescribed movements using a variational approach. By dividing the trajectories into time intervals, a mixed-integer programming (MIP) model delivers double-cycle plans. For longer down movements the shape of optimal trajectories would be technically disadvantageous which requires alternatives to avoid the abrasion of the devices.