The optimization of ship weather-routing algorithm based on the composite influence of multi-dynamic elements (II): Optimized routings

• In this paper, two types of optimized routings, i.e. ETA and FUEL, have been verified by means of elaborated objective functions with constraints of 3DMI method. By considering the influences of safety constraints on both of these optimized routings, it is found that total fuel consumption and voyage distance of ETA routings appear an increase value in comparison to the decrease of FUEL routings.
• The results also show that ATAs of ETA routings are generally in proportional to the given ETAs, in contrast to random variations of ATAs from FUEL routings. By adjusting the safety threshold, the robustness of the 3DMI method is verified to be a practical tool for the trade-off of ship efficiency and economics.

The ship routing problem can be known as a multi-objective problem. Since the operation strategy is influenced by ocean environments, e.g. wind, waves or ocean currents, it is therefore weather routed. In this study, the three-dimensional modified isochrone (3DMI) method utilizing the recursive forward technique and floating grid system for the ship tracks is applied to globally search for the optimum route. The proposed method considers two types of routing strategies, i.e. ETA (Estimated Time of Arrival) routing and FUEL (FUEL-saving) routing, with different constraints, such as land boundaries, significant wave heights, engine revolution speeds and roll responses. As a result, it is verified that the robustness of the proposed method appears to be a practical tool by adjusting the safety threshold for the trade-off of ship efficiency and economics.