The Integrated Scheduling for the Multi-Stage Transshipment System Considering AGVs and ETs

In sea-road intermodal container terminals, the integrated scheduling problem for the multi-stage transshipment system (ISP _ MST _ CT) is influenced by factors such as the number of containers, multi-stage interactions, and various types of equipment, making it challenging to construct the model. Additionally, assigning an appropriate number of AGVs to the transshipment tasks can significantly avoid resource waste at the terminals. This paper, for the first time, considers the ISP _MST_CT of quay cranes, AGVs, yard cranes, and external trucks, encompassing four operational stages. A mixed-integer programming model is formulated to simultaneously optimize the maximum completion time, total energy consumption of quay cranes and yard cranes, and total waiting time of AGV s. The nondominated sorting genetic algorithm II (NSGAII) algorithm is employed to solve this problem. The experiment results validate that NSGAII is capable of efficiently solving ISP _ MST _ CT of different scales and obtaining superior solutions within a short time. Furthermore, a series of experiments with 20 containers demonstrates that 8 AGVs can keep the balance among the three optimization objectives, while reducing the waste of AGVs and providing valuable insights to terminal managers.