SYSTEMS AND METHODS FOR DYNAMIC POSITIONING

• US 20150346730A1
• Filed: 06/02/2015
• Published: 12/03/2015
• Est. Priority Date: 06/03/2014
• Status: Abandoned Application

• Current Assignee: GE Energy Power Conversion Technology Limited (General Electric Company)
• Original Assignee: GE Energy Power Conversion Technology Limited (General Electric Company)
• Inventors: STEPHENS, Richard Ian, WILKINS, Anthony John
• Application Number:
  US14/728,142
• Publication Number:
  US 20150346730A1
• Time in Patent Office: Days
• US Class Current: 1/1
• 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
• CPC Class Codes: G05D 1/0206 specially adapted to water vehicles
• CPC Class Codes: G05D 1/0208 dynamic anchoring

Abstract

A system for minimizing fuel consumption in a dynamic positioning (DP) vessel comprising a measurement system, an observer system, a control system and a thruster system. The heading of the vessel is adjusted to minimize the environmental forces felt on each side of the vessel. The method also allows for operator input to offset the vessel heading to improve comfort on board.

Claims

1. A dynamic positioning system, comprising

a controller, comprising:

a processor; and

a memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising;

calculating, by the processor;

a sum value based on a sum of one or more measured values of sway environmental force;

a multiplied value based on a product of the sum value and a controller gain;

a heading offset angle based on an integral of the multiplied value over time; and

an aim heading based on a sum of an initial heading and the heading offset angle.

2. The dynamic positioning system of claim 1, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising generating a thruster control signal based on the aim heading.

3. The dynamic positioning system of claim 1, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising:

calculating a sway force offset based on a tangent of an operator offset angle multiplied by a measured value of surge environmental force;

calculating the sum value based on a sum of;

the one or more measured values of sway environmental force; and

the sway force offset.

4. The dynamic positioning system of claim 3, wherein the sway force offset is calculated based on:

Δ

F_ey=F_ex*K_x2y tan(δ

)

wherein Δ

F_ey is the sway force offset, F_ex is the surge environmental force, K_x2y is an offset gain, and δ

is the operator offset angle.

5. The dynamic positioning system of claim 3, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising:

calculating an offset gain based on a sway wind force coefficient and a surge wind force coefficient; and

calculating the sway force offset based on the tangent of the operator offset angle, multiplied by the measured value of surge environmental force, and multiplied by the offset gain.

6. The dynamic positioning system of claim 5, wherein the offset gain is calculated based on:

7. The dynamic positioning system of claim 3, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising calculating:

calculating, a value of a multiplier based on a wind speed divided by the surge environmental force;

determining a value of an adjusted value, wherein the value of the adjusted value is;

equal to the value of the multiplier if an absolute value of the multiplier is less than one;

or

equal to one if the absolute value of the multiplier is greater than one; and

calculating the multiplied value based on a product of the sum value, the controller gain, and the adjusted value.

8. The dynamic positioning system of claim 7, wherein the multiplier is calculated based on:

9. The dynamic positioning system of claim 8, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising calculating the multiplier when the wind speed exceeds a predetermined velocity.

10. The dynamic positioning system of claim 8, wherein the sway force offset is calculated based on:

Δ

F_ey=F_ex*K_x2y tan(δ

)

wherein Δ

F_ey is the sway force offset, F_ex is the surge environmental force, K_x2y is an offset gain, and δ

is the operator offset angle.

11. The dynamic positioning system of claim 10, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising:

calculating the offset gain based on a sway wind force coefficient and a surge wind force coefficient.

12. The dynamic positioning system of claim 11, wherein the offset gain is calculated based on:

13. The dynamic positioning system of claim 1, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising:

comparing the heading offset angle to a limit; and

selecting the heading offset angle as the limit if the heading offset angle is greater than the limit.

14. The dynamic positioning system of claim 1, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising calculating:

calculating, a value of a multiplier based on a wind speed divided by a surge environmental force;

determining a value of a adjusted value, wherein the value of the adjusted value is;

equal to the value of the multiplier if an absolute value of the multiplier is less than one;

or

equal to one if the absolute value of the multiplier is greater than one; and

calculating the multiplied value based on a product of the sum value, the controller gain, and the adjusted value.

15. The dynamic positioning system of claim 14, wherein the multiplier is calculated based on:

16. The dynamic positioning system of claim 1, comprising a measurement system that is configured to measure weather conditional data, the memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising calculating the one or more measured values of sway environmental force based on the weather conditional data.

17. The dynamic positioning system of claim 16, wherein the weather conditional data includes wind speed and direction.

18. The dynamic position system of claim 1, comprising a thruster system.

19. The dynamic positioning system of claim 18, the thruster system comprising at least one of a tunnel thruster, an azimuth thruster, a rudders, a propeller, a water jet, and a cycloidal propeller.

20. A controller for a dynamic positioning system, comprising:

a processor; and

a memory having stored thereon computer-executable instructions which, when executed by the processor, cause the processor to perform operations comprising;

calculating, by the processor;

a sum value based on a sum of one or more measured values of sway environmental force;

a multiplied value based on a product of the sum value and a controller gain;

a heading offset angle based on an integral of the multiplied value over time; and

an aim heading based on a sum of an initial heading and the heading offset angle.