Integrated Scheduling of Automatic Guided Vehicles and Automatic Stacking Cranes in Automated Container Terminals Considering Landside Buffer Zone

The enhancement of the efficiency of automated container terminals (ACTs) and promotion of energy saving and emission reduction have attracted increasing attention in the construction of resource-saving and environment-friendly ports. In this paper, an integrated scheduling optimization model of automatic guided vehicles (AGVs) and automatic stacking cranes (ASCs) is proposed to resolve the problem of long round trips and high energy consumption of ASCs in typical ACTs. The configurations of ACTs considering the landside buffer zone were analyzed. First, the feasibility of integrated scheduling when considering a landside buffer zone is introduced. The study also analyzes the problems that must be resolved for the integrated scheduling of AGVs and ASCs using the aforementioned layout handling technology. Subsequently, a multi-objective optimization model for the integrated scheduling of AGVs and ASCs considering the landside buffer zone was developed. In this model, the operations of AGVs and ASCs are divided into four categories: load transport, no-load transport, load/unload, and waiting. The objective of formulating the model was to minimize the makespan and total energy consumption. Finally, an improved non-dominated ranking genetic algorithm, NSGA-II, is employed to optimize the model. The results show that the makespan and total energy consumption of the integrated scheduling of AGVs and ASCs considering the landside and seaside buffer zones are better than those considering only the seaside buffer zone.