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.

In this paper, an Improved Ant Colony Algorithm is applied to the identification of the ship motion modelNomotos 1st-order nonlinear model. A robust method based on Ant Colony Algorithm is proposed for the optimization of the continuous function. The transfer criterion of the ants between each layer and global pheromone updating process are described. Some experiments results show that this method has good identification accuracy. The algorithm is feasible and effective, is of enormous significance to the system identification of ship motion.

This paper introduced a leveling tanks system of the ship based on Visual C++. The simulation system is consisted of a leveling tank, a leveling system controller and a ship motion simulator three parts. This paper focuses on the system leveling effect, when the roll is generated by steering as well as loading and wave interference under conditions of direct of the ship. In the research of the ship rolling, which is generated by steering, tanks model combining of traditional four degrees of freedom, getting a new four degrees of freedom "Ship-Tank" movement mathematical model. We calculate the motion state of the ship, and output multiple parameter information of ship motion based on the mathematical model, and then level the roll motion generated by ship steering using control strategies. Simulation results show that, in the conditions of both direct and steering, the system is able to achieve the desired effect of leveling, and thereby it provides reliable basics for designing and researching of leveling tanks.