Conflict-free routing and flowpath design for automated guided vehicles in container terminals

Abstract

As the scale of container shipping continuously increases driven by mega vessels and rising transportation demands, Automated Container Terminals (ACTs) have emerged as a promising solution to enhance operational efficiency, leveraging technologies such as automated guided vehicles (AGVs) for container transporting tasks. The AGV traffic within the transportation area, serving as a critical link between quayside and yard side operations, faces challenges due to complex conflicting relations among AGV movements. This study proposes a novel framework for routing and flowpath design (RFD) problem of AGVs in ACTs.Through investigating conflicting mechanisms of AGV movements, the study first proposes conflict-free principles for elementary grid networks, aiming to achieve conflict-free operations and enhance traffic efficiency. Theoretical analysis validates the maximum space–time resource utilization of the RFD under certain conditions. Furthermore, customized design methods are developed to adapt to real-world ACT scenarios, and an integrated optimization model is established to optimize RFD schemes. Numerical experiments are conducted to evaluate the proposed methods, highlighting their effectiveness in enhancing operational efficiency and mitigating traffic congestion in ACTs. This study provides a streamlined yet effective approach to AGV traffic organization within container terminals. By proactively resolving AGV travel conflicts, it addresses the computational challenges in real-time implementation and serves as a cornerstone for effective online operation of AGVs.