Fuzzy Scheduling Problem of Vessels in One-Way Waterway

Abstract

Effective use of port waterways is conducive to enhancing port competitiveness. To minimize the waiting time of ships, improve traffic efficiency, and enhance the applicability of the model to the presence of uncertain factors, a fuzzy scheduling optimization method for ships suitable for one-way waterways is proposed based on fuzzy theory. Considering the ambiguity of the speed of ships entering and exiting the port or the time it takes to cross the channel, the previous research on vessel scheduling on one-way waterways has been extended by introducing a triangular fuzzy number and a method for determining the feasible navigable time window of a ship subject to the tide height constraint was proposed. In this study, the genetic algorithm is used to construct the mathematical model for solving fuzzy vessel scheduling problems based on time optimization, and the minimum delay strategy is used to determine the service sequence. Then, the parameters setting are discussed in detail to find the optimal settings. Finally, an experimental comparative analysis of the randomly generated cases was conducted based on the simulated data. The results show that the designed fuzzy vessel scheduling algorithm reduces the dependence on the port environment, is versatile, and can effectively improve the efficiency of ship schedules and traffic safety compared to other methods. Moreover, it can avoid the problem of the illegal solution occurring in the manual scheduling method.

Dynamic Tugboat Scheduling for Large Seaports with Multiple Terminals

“…Common optimization objectives are designed from two perspectives: minimizing the total cost or maximizing resource utilization. The total cost being considered includes the sailing distance of the tugboat, the waiting time of the ship [9,18,21,24], the operation time or cost of the tug [10,26,27], and the fuel cost of the tugboat [12,15,28], etc. Maximizing resource utilization refers to ensuring that tugboat resources are fully utilized, minimizing idle time [16,17].…”

Departure Vessel Scheduling Optimization Considering Traffic Restrictions in Turning Basin: A Case Study for Xuwen Terminal

“…And ship j turns around after the distance between ship i and ship j is greater than S r . Constraints (11) and (12) indicate that two ships in consecutive order must maintain a minimum distance of S v when they navigate in the turning basin or fairway.…”

“…To minimize the weighted dwelling time of vessels, Liu et al [10] came up with a mixed-integer linear programming (MILP) formulation. Liu et al [11] applied fuzzy theory to optimize ship scheduling in a one-way waterway. This approach improved the adaptability of the scheduling system to uncertain external factors.…”

Research on safety and efficiency warranted vessel scheduling in unidirectional multi-junction waterways of port waters

“…Some works have discussed the effects of speed, but there are still few relevant studies. Liu et al, (2021a) proposed a fuzzy scheduling optimization method considering different speed of vessels. The WSSP was extended by introducing a triangular fuzzy number and a method for determining the feasible navigable time window of a vessel subject to the tide height constraint.…”