Scheduling intelligent guided vehicles for automated container terminals with lighterage mode consideration

To reduce the number of operational steps at automated container terminals (ACTs), the lighterage mode is implemented, allowing intelligent guided vehicles (IGVs) to transport ship-to-ship transfer containers without going through the yard. However, challenges including inflexible mode decision for ship-to-ship transfer, low load utilisation of IGVs, and short-sighted allocation of yard resources are hindering the effective implementation of lighterage mode. To address these challenges, a comprehensive IGV transport strategy is proposed in this study. The proposed strategy accommodates transport tasks of ship-to-ship transfer containers through the integration of three components: (1) container-based mode decision for ship-to-ship transfer; (2) IGV transport under multi-load operation; and (3) synchronised yard block selection. A mathematical model is established to depict the dynamic process of IGVs serving liners, barges, and yard blocks with lighterage mode considerations. A multi-start simulated annealing algorithm with periodic quenching is then developed for the model. Compared to classic algorithms, ours takes advantage of reducing randomness and avoiding entrapment in local optima. Computational experiments across varying instances indicate that the proposed algorithm, together with the three-component integrated strategy, effectively enhances the IGV operational efficiency for ACTs implementing lighterage mode without the need to increase the number of IGVs.