Parameter Identification of the Maneuvering Model for Large Vessel Sailing in Different Conditions

The ship autopilot is designed based on the exact model to ensure high security and good performance. In order to obtain exact parameters of the model in different environment conditions, this paper proposes a method which identifies the parameters in calm and severe sea condition respectively. In calm sea condition, it identifies the steerability parameter K through constant rudder angle maneuvering at first. After the constant rudder angle maneuvering, it identifies the time parameter T through zero rudder angle maneuvering. In severe sea condition, the ship course is interfered by strong wave interference and the identification approach used in calm sea is ineffective. It considers the ship manipulation as an ARMAX model and uses prediction-error approach to identify the transfer function of the ship maneuvering. Finally, it tests performances of the proposed identification algorithm through some experiments, and the results show that the proposed algorithm adapts to different conditions.