Electrical Actuator for Ship Roll Stabilization.
Patent, Filed 31 Mar 81, patented 21 Jun 83,
DEPARTMENT OF THE NAVY WASHINGTON DC
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This patent discloses compensate for wind and wave induced roll motions includes a hydraulically actuated mechanism for controlling the position of the rudders a pump coupled to the hydraulic mechanism for controlling the flow of hydraulic fluid and a flow control device connected to the pump for controlling the flow rate of fluid through the pump. The roll reduction signal processed by the second actuation device consists of the instantaneous roll rate of the ship and the statistical rate gain factor K that represents the reciprocal of the time-average roll rate, modified by the maximum allowable rudder rate and the natural roll period of the vessel. The rate gain circuit for producing the rate gain factor includes an absolute value circuit, a smoothing filter, a minimum value circuit, a divider circuit, and a second smoothing filter.
- Marine Engineering