Determination pivot point position and its use for maneuvering the vessel.

Abstract

Deflection of the stern rudder causes the simultaneous appearance of both lateral force and control torque, which lead to the simultaneous occurrence of lateral speed and angular rate of the vessel around the rotation centre. It is noted that the complex motion of the vessel, consisting of lateral motion and rotational motion, can be replaced with one rotational motion around a point called the pivot point. In all known works, the authors determine the position of the pivot point and give general recommendations for its use during maneuvering. But for the navigator it is important to know how to deflect the controls in order to realize the rotation of the vessel around the given position of the pivot point. The following controls are investigated in the article: the areas of permissible controls and control lines on which the given movements are realized (rectilinear, without drift, around the pivot point) are constructed, the formula for calculating the control distribution coefficient is obtained, the optimal controls are considered.