STATION KEEPING METHODS

• US 20180231980A1
• Filed: 02/02/2018
• Published: 08/16/2018
• Est. Priority Date: 02/15/2017
• Status: Active Grant

• Current Assignee: Brunswick Corporation
• Original Assignee: Brunswick Corporation
• Inventors: Arbuckle, Jason S., Andrasko, Steven J., Van Buren, David M.
• Granted Patent: US 10,671,073 B2
• Time in Patent Office: Days
• CPC Class Codes: B63B 79/10 using sensors, e.g. pressure sensors, strain gauges or accelerometers
• CPC Class Codes: B63H 2025/026 using multi-axis control levers, or the like, e.g. joysticks, wherein at least one degree of freedom is employed for steering, slowing down, or dynamic anchoring
• CPC Class Codes: B63H 2025/045 making use of satellite radio beacon positioning systems, e.g. the Global Positioning System [GPS]
• CPC Class Codes: B63H 2025/425 Propulsive elements, other than jets, substantially used for steering or dynamic anchoring only, with means for retracting, or otherwise moving to a rest position outside the water flow around the hull
• CPC Class Codes: B63H 25/04 automatic, e.g. reacting to compass
• 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: B63J 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G05D 1/0206 specially adapted to water vehicles
• CPC Class Codes: G05D 1/0208 dynamic anchoring

Abstract

A method for maintaining a marine vessel at a global position and/or heading includes receiving measurements related to vessel attitude and estimating water roughness conditions based on the measurements. A difference between the vessel'"'"'s actual global position and the target global position and/or a difference between the vessel'"'"'s actual heading and the target heading are determined. The method includes calculating a desired linear velocity based on the position difference and/or a desired rotational velocity based on the heading difference. The vessel'"'"'s actual linear velocity and/or actual rotational velocity are filtered based on the roughness conditions. The method includes determining a difference between the desired linear velocity and the filtered actual linear velocity and/or a difference between the desired rotational velocity and the filtered actual rotational velocity. The method also includes calculating vessel movements that will minimize the linear velocity difference and/or rotational velocity difference and carrying out the calculated movements.

Claims

1. A method for maintaining a marine vessel at at least one of a target global position and a target heading in a body of water, the method being carried out by a control module and comprising:

receiving measurements related to an attitude of the marine vessel;

estimating roughness conditions of the body of water based on the attitude measurements;

determining at least one of a difference between an actual global position of the marine vessel and the target global position and a difference between an actual heading of the marine vessel and the target heading;

calculating at least one of a desired linear velocity based on the position difference and a desired rotational velocity based on the heading difference;

based on the roughness conditions, filtering at least one of an actual linear velocity of the marine vessel and an actual rotational velocity of the marine vessel;

determining at least one of a difference between the desired linear velocity and the filtered actual linear velocity and a difference between the desired rotational velocity and the filtered actual rotational velocity;

calculating marine vessel movements that will minimize the at least one of the linear velocity difference and the rotational velocity difference; and

operating a propulsion system of the marine vessel to carry out the calculated marine vessel movements.

2. The method of claim 1, wherein the attitude measurements are vessel pitch measurements and vessel roll measurements.

3. The method of claim 2, further comprising estimating the roughness conditions by calculating a variance of the pitch measurements and a variance of the roll measurements.

4. The method of claim 3, further comprising storing the pitch measurements and the roll measurements in respective circular buffers in a storage system of the control module.

5. The method of claim 3, further comprising filtering at least one of the position difference and the heading difference based on the roughness conditions;

and

calculating the at least one of the desired linear velocity based on the filtered position difference and the desired rotational velocity based on the filtered heading difference.

6. The method of claim 5, further comprising filtering a fore/aft component of the position difference and a fore/aft component of the actual linear velocity based on the variance of the pitch measurements;

and

filtering a left/right component of the position difference and a left/right component of the actual linear velocity based on the variance of the roll measurements.

7. The method of claim 6, further comprising filtering the heading difference and the actual rotational velocity based on the variance of the roll measurements.

8. The method of claim 1, further comprising setting the desired linear velocity to zero in response to the position difference being inside a predefined position difference hysteresis band;

and

setting the desired rotational velocity to zero in response to the heading difference being inside a predefined heading difference hysteresis band.

9. The method of claim 8, further comprising determining the position difference hysteresis band and the heading difference hysteresis band based on the roughness conditions.

10. The method of claim 1, further comprising calculating the marine vessel movements that will minimize the at least one of the linear velocity difference and the rotational velocity difference using a proportional, integral, derivative (PID) control algorithm;

and

determining at least one of a proportional gain, a derivative gain, and an integral gain for use in the PID control algorithm based on the roughness conditions.

11. The method of claim 1, further comprising carrying out the calculated marine vessel movements in response to the calculated marine vessel movements being outside of a predetermined deadband.

12. A system for maintaining a marine vessel at at least one of a preselected global position and a preselected heading, the system comprising:

a control module in signal communication with a propulsion system of the marine vessel;

a pitch sensor that provides vessel pitch measurements to the control module;

a roll sensor that provides vessel roll measurements to the control module;

a heading sensor that provides a measured heading of the marine vessel to the control module; and

a position sensor that provides a measured global position of the marine vessel to the control module;

wherein the control module determines at least one of a difference between the measured global position and the preselected global position and a difference between the measured heading and the preselected heading;

wherein the control module calculates at least one of a desired linear velocity based on the position difference and a desired rotational velocity based on the heading difference;

wherein, based on the pitch measurements and the roll measurements, the control module filters at least one of an actual linear velocity of the marine vessel and an actual rotational velocity of the marine vessel;

wherein the control module determines at least one of a difference between the desired linear velocity and the filtered actual linear velocity and a difference between the desired rotational velocity and the filtered actual rotational velocity; and

wherein the control module calculates marine vessel movements that will minimize the at least one of the linear velocity difference and the rotational velocity difference and causes the propulsion system to operate to carry out the calculated marine vessel movements.

13. The system of claim 12, wherein the control module calculates a variance of the pitch measurements and a variance of the roll measurements and filters the at least one of the actual linear velocity and the actual rotational velocity based on the variance of the pitch measurements and the variance of the roll measurements.

14. The system of claim 13, wherein the control module filters at least one of the position difference and the heading difference based on the variance of the pitch measurements and the variance of the roll measurements;

and

wherein the control module calculates the at least one of the desired linear velocity based on the filtered position difference and the desired rotational velocity based on the filtered heading difference.

15. The system of claim 14, wherein the control module filters a fore/aft component of the position difference and a fore/aft component of the actual linear velocity based on the variance of the pitch measurements;

and

wherein the control module filters a left/right component of the position difference and a left/right component of the actual linear velocity based on the variance of the roll measurements.

16. The system of claim 15, wherein the control module filters the heading difference and the actual rotational velocity based on the variance of the roll measurements.

17. The system of claim 13, wherein the control module sets the desired linear velocity to zero in response to the position difference being inside a predefined position difference hysteresis band;

and

wherein the control module sets the desired rotational velocity to zero in response to the heading difference being inside a predefined heading difference hysteresis band.

18. The system of claim 17, wherein the control module determines the position difference hysteresis band and the heading difference hysteresis band based on the variance of the pitch measurements and the variance of the roll measurements.

19. The system of claim 13, wherein the control module calculates the marine vessel movements that will minimize the at least one of the linear velocity difference and the rotational velocity difference using a proportional, integral, derivative (PID) control algorithm;

and

wherein the control module determines at least one of a proportional gain, a derivative gain, and an integral gain for use in the PID control algorithm based on the variance of the pitch measurements and the variance of the roll measurements.

20. The system of claim 12, wherein the control module causes the propulsion system to operate to carry out the calculated marine vessel movements in response to the calculated marine vessel movements being outside of a predetermined deadband.