Method and device for producing substantially kinematic steering of a vessel
AssigneeKockums Automation AB
InventorsBror Folke Hedstrom, Per Thorvald Persson
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Abstract
The invention provides a method and device for producing substantially kinematic steering of a vessel in a yaw path having a given radius of curvature conforming with a predetermined control law. During the steady state phase of the yaw when there exist conditions for dealing with an easily controllable radius of curvature and in the vessel is steered by rudder deflection changes and by utilizing servo control methods in such a way that the radius of curvature of the vessel, which has been determined by instrument facilities aboard the vessel, follows a predetermined suitable program for the yaw curvature during the yaw.
Claims37
A method for substantially producing kinematic steering of a vessel in a yaw path having a given radius of curvature conforming with a predetermined control law, comprising the steps of:
- determining, in a path model, the set of values of one of the quantities radius of path curvature R.sub.b and path angular rate .omega..sub.b =V/R.sub.b of the vessel;
- determining the actual value of the path angular rate .omega..sub.a and the radius of path curvature R.sub.a =V/.omega..sub.a of the vessel, V being a measure at least approximately of the speed over ground of the vessel;
- generating a control signal from the values thus determined, which is a function of a quantity which represents the difference R.sub.b-R.sub.a, and effecting in dependence thereon a change of a rudder position of said vessel required for minimizing said control signal.
A device for substantially producing kinematic steering of a vessel in a yaw path having a given radius of curvature conforming with a predetermined control law, comprising:
- means for determining the actual value of the path angular rate .omega..sub.a and the actual value of the radius of path curvature R.sub.a =V/.omega..sub.a of the vessel, V being a measure at least approximately of the speed over ground of the vessel;
- means for generating a control signal from said actual values and from the set value of one of the quantities:
- radius of path curvature R.sub.b and path angular rate .omega..sub.b =V/R.sub.b, R.sub.b and .omega..sub.b being determined by means of a preselected path model, said control signal being a function of a quantity of which represents the difference R.sub.b -R.sub.a, and means for utilizing said control signal for adjusting a rudder position of the vessel.
Dependencies are inferred from the claim text.