AGV charging scheduling with capacitated charging stations at automated ports

With technological advancements and a growing focus on environmental sustainability, battery-powered automated guided vehicles (AGVs) have gained widespread adoption in automated container ports. Consequently, the scheduling of AGV charging has emerged as a crucial issue. However, research on AGV charging in the context of automated ports is limited, often neglecting the interactions between different types of equipment such as quay cranes (QCs) and yard cranes (YCs). Additionally, the limited capacity of charging stations (CSs) is often overlooked. We investigate an AGV charging scheduling problem with capacitated CSs, to minimize the operation time of AGVs for completing given discharging and loading tasks. We use a path-based method to formulate the problem as a mixed integer programming model. Also, a matheuristic framework combining mathematical models with heuristics is developed to address the considered problem. Numerical results based on small-scale and large-scale instances demonstrate the effectiveness of the proposed method. We find that some measures, namely a flexible charging policy and broader container distribution, can lead to reduced AGV total operation time and task makespan.