Patent ID: 9145191
Filing Date: 2015-09-29
Classification: B63B

Abstract:
1. A method for averting and damping rolling of a marine ship with propeller propulsion, wherein the current heel angle of the ship is sensed and a sequence of said sensed heel angles is used to compute values that characterize the behavior of ship's rolling comprising rolling amplitude, rolling period and trends of the rolling amplitude and rolling period, a model is used to characterize the behavior of ship's rolling as a critical interaction between the ship's dynamics and the ship's engine/propeller speed controller, said critical interaction increases or maintains the rolling of the ship, signals that are related to the ship's rolling, including their derivatives of first and second order, and parameters that effect ship's rolling, characterize together the ship's dynamics and are used in the said model, and a selection of a proper control algorithm is done, based on said ship's rolling model and on said rolling trend data to avert and damp said critical interaction between the ship's dynamics and the engine/propeller speed controller by modifying the function of the engine/propeller speed regulator such that said critical interaction is counteracted.