What is the Pivot Point and how to use it to control the vessel.

Abstract

Determining the position of the pivot point relative to the center of gravity is not entirely correct, since the vessel does not rotate relative to the center of gravity, but relative to the center of rotation. In addition, in known solutions were given only recommendations how to take into account the position of the pivot point, but not given a specific methods and algorithms for calculating the rotation control of a vessel around a pivot point. It is shown that the rotation centre, the pivot point and the gravity centre of the vessel are three different points, which, in the general case, do not coincide with each other: rotation center of the vessel located at the point relative to which the vessel will have the greatest angular acceleration from the applied torque; there were constructed the areas of admissible controls in which the required rotations are realized; it was obtained optimal motion control around the pivot point; the correctness of the method and algorithms were verified by mathematical modeling on a navigation simulator Navi Trainer 5000.