Vessel Stabilization Apparatus and Method

Abstract

A method for controlling the motion of marine vessel ( 10 ) comprises mounting a gyroscope ( 12 ) in a gimbal and fixing the gimbal inside the vessel. In one arrangement, a trunnion axis ( 18 ) of the gimbal is mounted athwart the vessel ( 10 ). Sensors ( 20 ) are mounted at various locations on the vessel ( 10 ), as well as on the gyroscope ( 12 ), to measure the motion of the vessel ( 10 ), including motion caused by wave action. Signals from the sensors ( 20 ) are processed by a computer that in turn controls a motor to apply a force about the trunnion axis ( 18 ) to the gyroscope ( 12 ) in a direction that causes the gyroscope ( 12 ) to provide a reactive torque urging the vessel ( 10 ) to follow the slope of the wave and reduce the motion in the vessel ( 10 ). Thus, the method causes the gyroscope to apply reactive force that causes the vessel ( 10 ) to follow the slope of the waves acting on the vessel. This in essence eliminates hydrodynamic and hydrostatic force on the vessel and therefore prevents resonance of the vessel ( 10 ) with the waves.

1 . A method for controlling the motion of a vessel comprising the steps of:
 installing a first gyroscope having a flywheel in a vessel, said gyroscope mounted in a gimbal having a trunnion axis aligned in a plane containing motion of a vessel created by wave motion that is desired to be controlled;   spinning said flywheel about a spin axis;   sensing said motion of said vessel caused by a wave having a wave slope; and   on the basis of said sensed motion, applying a force to or about said trunnion axis in a direction so that said gyroscope produces a reactive torque which is applied to said vessel in a manner to urge said vessel to follow said wave slope.   
   
   
       2 . The method according to  claim 1 , wherein said installing comprises mounting said gyroscope with said trunnion axis orientated athwart said vessel. 
   
   
       3 . The method according to  claim 1 , wherein said installing comprises mounting said gyroscope with said trunnion axis aligned fore and aft of said vessel. 
   
   
       4 . The method according to  claim 1 , wherein said spin axis is substantially vertical. 
   
   
       5 . The method according to  claim 1 , wherein said spin axis is substantially horizontal. 
   
   
       6 . A method for controlling roll motion of a vessel comprising the steps of:
 installing a gyroscope in said vessel, said gyroscope having a spin axis in a vertical plane and mounted in a gimbal having a trunnion axis aligned athwart said vessel;   sensing roll of said vessel caused by a wave having a wave slope; and   on the basis of said sensed motion and/or forces, applying a force to or about the trunnion axis in a direction so that said gyroscope produces a reactive torque which is applied to said vessel in a manner to roll said vessel to follow said wave slope.   
   
   
       7 . A method for controlling pitch motion of a vessel comprising the steps of:
 installing a gyroscope in said vessel, said gyroscope having a spin axis in a vertical plane and mounted in a gimbal having a trunnion axis aligned fore and aft of said vessel;   sensing pitch motion of and/or forces applied to said vessel caused by a wave having a wave slope; and   on the basis of said sensed motion and/or forces, applying a force to or about the trunnion axis in a direction so that said gyroscope produces a gyroscopic pitch torque which is applied to said vessel in a manner to pitch said vessel to follow said wave slope.   
   
   
       8 . A method for controlling the motion of a vessel having an athwart axis and a fore and aft axis comprising the steps of:
 installing a gyroscope having a flywheel in a vessel, said gyroscope mount in a gimbal having a trunnion axis parallel to one of said athwart axis and fore and aft axis to control roll motion of said vessel about the other of said athwart axis and fore and aft axis generated by wave motion;   spinning said flywheel about a spin axis;   sensing said motion of said vessel caused by a wave having a wave slope; and   on the basis of said sensed motion, applying a force to or about said trunnion axis in a direction so that said gyroscope produces a reactive torque which is applied to said vessel in a manner to urge said vessel to follow said wave slope.   
   
   
       9 . The method according to  claim 1  further comprising installing a second gyroscope in said vessel. 
   
   
       10  The method according to  claim 1  wherein the installing step comprises installing a plurality of pairs of gyroscopes in said vessel, wherein the first gyroscope is part of one of said plurality of pairs of gyroscopes. 
   
   
       11 . The method according to  claim 9 , wherein the trunnion axes of the gyroscopes are parallel to each other. 
   
   
       12 . The method according to  claim 1 , wherein the force applied to the trunnion axis is applied in a non-linear manner. 
   
   
       13 . The method according to  claim 6 , wherein the force applied to the trunnion axis is applied in a non-linear manner. 
   
   
       14 . The method according to  claim 7 , wherein the force applied to the trunnion axis is applied in a non-linear manner. 
   
   
       15 . The method according to  claim 8 , wherein the force applied to the trunnion axis is applied in a non-linear manner. 
   
   
       16 . The method according to  claim 10 , wherein the trunnion axis of the gyroscopes are parallel to each other.