等時間 Z 操舵による船の応答について

抄録

This paper describes ship response by “zigzag maneuver with equal time-alternative steering”. This maneuver runs as follows: firstly the helm is turned to a certain angle during a certain time, secondly it is turned to the opposite side to the same angle during the same time, and thirdly it is returned again to the original position. In this maneuver, the analytical solutions of response, that is, angular velocity, heading angle and trajectory, etc., are obtained using first order model of Nomoto. These equations clarify the relationship between the steering quality indices and the ship response. The response of actual ships from published existing data is also checked out using the equations. The obtained charts summarized here will be available for design review of maneuverability. Finally, the trajectories are analyzed under some conditions that for instance the ships have the same non-dimensional steering quality indices and the different ship lengths. The significant difference of them indicates it is effective to consider trajectory in the early stage of design.