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Summary The paper is devoted to the problem of control law optimization for marine ships, which are steered by autopilots under the action of sea disturbances, mainly determined by bias terms and high‐frequency wave components. The essence of the problem is to find a transfer function of the adjustable corrective item (filter) for the autopilot with a special structure, minimizing the functional, which characterizes the intensity of a ship's rudders action. The correspondent dynamic of a closed‐loop system provides an economical regime of the ship motion, with the aim to reduce general fuel consumption and to prevent the wear of actuator elements. A specialized approach to the filter design is proposed based on the modern H∞ optimization theory, and its applicability and effectiveness are illustrated by the practical example of autopilot synthesis for a transport ship. Copyright © 2015 John Wiley & Sons, Ltd.

Solving the problem of ship weather routing has been always a goal of nautical navigation research and has been investigated by many scientists. The operation schedule of an oceangoing ship can be influenced by wave or wind disturbances, which complicate route planning. In this paper, we present a real-coded genetic algorithm to determine the minimum voyage route time for point-to-point problems in a dynamic environment. A fitness assignment method based on an individual's position in the sorted population is presented, which greatly simplifies the calculation of fitness value. A hybrid mutation operator is proposed to enhance the search for the optimal solution and maintain population diversity. Multi-population techniques and an elite retention strategy are employed to increase population diversity and accelerate convergence rates. The effectiveness of the algorithm is demonstrated by numerical simulation experiments.

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