Joint Scheduling Optimization of Vessel and Tug Based on Improved NSGA-II Algorithm

To improve the efficiency of vessel scheduling in one-way channel port, a joint scheduling model of one-way channel vessel and tug is established, Considering the actual situation such as tug allocation and one-way channel navigation rules. The optimization objective of the model is to minimize the total waiting time of all vessels and the total cost of tugs service of all vessels. According to the characteristics of service time and navigation safety time and space constraints of vessels entering and leaving the port, we design a solution algorithm based on NSGA algorithm. Algorithm improvements include heuristic initialization population strategy, two-point crossover and single-parent crossover etc. The results of multi-group examples show that the improved algorithm is superior to NSGA-II algorithm in both target optimization and solving time, and the obtained scheduling scheme is consistent with the actual scheduling process. Compared with the first-come-first-serve scheduling scheme, the total waiting time is reduced by 46.5%, which greatly improves the efficiency of vessel scheduling. The research in this paper can provide reference for the vessel arrival and departure scheduling operation in one-way channel ports.