System and method for dynamic stabilization and navigation in high sea states

• US 8,215,252 B1
• Filed: 07/14/2009
• Issued: 07/10/2012
• Est. Priority Date: 07/14/2009
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Chun, Wendell H.
• Primary Examiner(s): Olson, Lars A
• Assistant Examiner(s): Polay, Andrew
• Application Number:
  US12/502,660
• Time in Patent Office: 1,092 Days
• Field of Search: 114/121, 114/144.R, 114/155, 114/144.RE, 114/144.B, 114/151, 440/51
• US Class Current: 114/121
• CPC Class Codes: B63B 39/005 Equipment to decrease ship's vibrations produced externally to the ship, e.g. wave-induced vibrations propulsion mountings for anti-vibration purposes B63H21/30; vibration dampers, suppression of vibration in systems F16F
• CPC Class Codes: B63B 39/08 to decrease vessel movements by using auxiliary jets or propellers for steering or dynamic anchoring B63H25/00
• CPC Class Codes: B63H 25/42 Steering or dynamic anchoring by propulsive elements by jets B63H25/46; Steering or dynamic anchoring by propellers used therefor only; Steering or dynamic anchoring by rudders carrying propellers

Abstract

A system is disclosed for dynamically stabilizing a ship in high sea states. A six degree-of-freedom robotic arm is attached to the ship, and a thruster is located at the distal end of the manipulator. The manipulator is be used to orient the thruster to counteract wave forces that act against the ship'"'"'s hull in real time. This active balancing technique can be used to keep the ship substantially erect in rough seas by making continual corrections to the ship'"'"'s body attitude. The center of gravity and the center of buoyancy of the ship are utilized, along with a precisely oriented and controlled thrust at the end of the manipulator, to optimally control the ship'"'"'s state against impending waves.

Claims

1. A system for stabilizing a floating body, comprising:

a manipulator connected to the floating body, the manipulator comprising an articulatable arm having a first end and a second end;

a thruster positioned on the manipulator, at least a portion of the thruster rotatable about an axis for generating thrust;

a first plurality of sensors for measuring at least a first characteristic of the floating body;

a second plurality of sensors for measuring a fluid force adjacent to the floating body; and

a controller in communication with the first and second plurality of sensors, the manipulator and the thruster;

wherein the second end of the articulatable arm is selectively rotatable with respect to the first end about at least three axes independent of the axis of rotation of the thruster;

wherein the controller is configured to adjust a position of the manipulator and the thruster based on information received from the first and second plurality of sensors; and

wherein the thrust generated by the thruster counteracts at least a portion of the measured fluid force.

2. The system of claim 1, wherein the articulatable arm comprises a plurality of rotatable joints, wherein the plurality of rotatable joints provide the second end of the manipulator with six independent degrees of freedom with respect to the first end.

3. The system of claim 2, wherein the first end of the manipulator is connected to the floating body and the thruster is connected to the second end of the manipulator.

4. The system of claim 1, wherein the thruster comprises a propeller.

5. The system of claim 1, wherein the first characteristic comprises at least one of the center of gravity and the center of buoyancy of the floating body.

6. The system of claim 1, wherein the first plurality of sensors are selected from the list consisting of gyroscopes and accelerometers.

7. The system of claim 1, wherein the second plurality of sensors comprise load cells for measuring a fluid force.

8. The system of claim 1, further comprising a plurality of manipulator sensors disposed on the manipulator, wherein the manipulator sensors provide information to the controller to facilitate positioning of the manipulator.

9. The system of claim 8, wherein the articulatable arm further comprises three joints for rotating the second end about the three axes, and at least a portion of the plurality of manipulator sensors are positioned at the three rotatable joints.

10. The system of claim 1, further comprising a navigation system and a camera for sensing visual information regarding a sea state surrounding said floating body, wherein the controller is configured to receive information from said camera and to provide navigation information to the navigation system.

11. The system of claim 10, wherein the navigation system further comprises a global positioning system (GPS) and a navigation radar.

23. The system of claim 1, wherein the articulatable arm comprises three rotatable joints, each of the joints defining one of the three axes of rotation.

24. The system of claim 1, wherein the three axes of rotation comprise three mutually orthogonal axes of rotation.

27. The system of claim 1, wherein the distance between the first end and the second end of the articulatable arm may be altered by rotating the second end of the manipulator arm about at least one of the three axes.

12. A system for stabilizing a floating body, comprising:

a manipulator connected to the floating body, the manipulator comprising an arm having a first end and a second end, the second end rotatable with respect to the first end about at least three orthogonal axes;

a thruster positioned on the manipulator arm;

a first plurality of sensors for measuring at least a first characteristic of the floating body;

a second plurality of sensors for measuring a fluid force adjacent to the floating body; and

a controller configured to adjust a position of the manipulator arm and the thruster based on information received from the first and second plurality of sensors;

wherein a thrust generated by the thruster counteracts at least a portion of the measured fluid force; and

wherein the manipulator arm comprises a plurality of joints for providing the second end of the manipulator arm with six independent degrees of freedom with respect to the first end.

13. The system of claim 12, wherein the manipulator arm comprises three rotatable joints, each of the joints defining one of the three axes of rotation.

14. The system of claim 12, wherein the first end of the manipulator is connected to the floating body and the thruster is connected to the second end of the manipulator arm.

15. The system of claim 12, wherein the thruster comprises a propeller disposed in a flow duct.

16. The system of claim 12, wherein the first characteristic comprises at least one of the center of gravity and the center of buoyancy of the floating body.

17. The system of claim 12, wherein the first plurality of sensors are selected from the list consisting of gyroscopes and accelerometers.

18. The system of claim 12, wherein the second plurality of sensors comprise load cells for measuring a fluid force.

19. The system of claim 12, further comprising a plurality of manipulator sensors disposed on the manipulator, wherein the manipulator sensors provide information to the controller to facilitate positioning of the manipulator.

20. The system of claim 19, wherein the manipulator arm further comprises three rotatable joints, and at least a portion of the plurality of manipulator sensors are positioned at the three rotatable joints of the manipulator arm.

21. The system of claim 12, further comprising a navigation system and a camera for sensing visual information regarding a sea state surrounding said floating body, wherein the controller is configured to receive information from said camera and to provide navigation information to the navigation system.

22. The system of claim 21, wherein the navigation system further comprises a global positioning system (GPS) and a navigation radar.

26. The system of claim 12, wherein the plurality of joints comprises at least six rotatable joints.

28. The system of claim 12, wherein the distance between the first end and the second end of the manipulator arm may be altered by rotating the second end of the manipulator arm about at least one of the three axes.

25. A system for stabilizing a floating body, comprising:

a manipulator connected to the floating body, the manipulator comprising an articulatable arm having a first end and a second end, the second end being selectively rotatable with respect to the first end about at least three axes;

a thruster positioned on the manipulator;

a first plurality of sensors for measuring at least a first characteristic of the floating body;

a second plurality of sensors for measuring a fluid force adjacent to the floating body; and

a controller in communication with the first and second plurality of sensors, the manipulator and the thruster;

wherein the articulatable arm comprises six rotatable joints for providing the second end of the manipulator with six degrees of freedom with respect to the first end;

wherein the controller is configured to adjust a position of the manipulator and the thruster based on information received from the first and second plurality of sensors; and

wherein a thrust generated by the thruster counteracts at least a portion of the measured fluid force.