Boat positioning and anchoring system

• US 20030191562A1
• Filed: 04/08/2002
• Published: 10/09/2003
• Est. Priority Date: 04/08/2002
• Status: Active Grant

• Current Assignee: Rhodan Marine Systems of Florida, LLC
• Original Assignee: Glen E. Robertson
• Inventors: Webster, John L., Robertson, Glen E.
• Granted Patent: US 6,678,589 B2
• Time in Patent Office: Days
• US Class Current: 701/21
• 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

An anchorless boat positioning system for establishing and maintaining a boat at a selected geographic location without the use of a conventional anchor. In one embodiment, a steerable thruster is used whose thrust and steering direction are determined and controlled on the basis of position information signals received from global positioning system (GPS) satellites, relative steering angle between the boat and the thruster and boat heading indication signals from a magnetic compass. The system continuously monitors the position and heading of the boat and compares it with the stored coordinates of the selected anchoring location(s) to generate control signals for the steerable motor. Several modes of operation are disclosed and Euler transformations for offset antenna placement for error reduction are taught. Proportional, integral, and derivative control (PID) of four constants of vessel control is also provided. Multiple thrusters in various arrangements are also provided to control either the orientation of the boat or a second point of interest on the boat at a second geographic location.

Claims

1. A system for substantially controlling the geographic position of the bow, or other part of a boat in water at a location selected by an operator of the boat thus virtually anchoring the boat, the system comprising:

a thruster means located in proximity to the bow, or point of interest, of the boat, said thruster capable of producing a steerable thrust force to move that part of the boat to the selected location, or virtual anchoring point, within the water;

a DGPS or WMS enabled receiver and antenna located onboard the boat for receiving signals from differential correction sources and GPS satellites, said receiver providing information as to the geographical position of said antenna, said antenna being collocated with the said thruster means in proximity to the bow, or point of interest on the boat;

an electronic means for providing information representative of the heading of the boat;

a controller receiving the information signals from said GPS receiver, said compass and said thrust direction relative to the heading of the boat, said thruster providing output signals to said thruster to control the direction and magnitude of the thrust, these output signals being computed as based on the calculated range and bearing to the desired anchoring site and upon the rate of change of range to the anchoring site;

a wireless manually activated remote control interface with which the operator of said boat can issue commands to said controller to control its mode of operation, said controller providing appropriate verbal responses via a loud speaker to inform the boat operator as to actions taken by said controller.

2. A system as set forth in claim 1, wherein:

the controller adjusts the magnitude of the thrust control signal based upon a long term average of range taken over an extended period of time and the thrust output signal is expressed substantially as;

thrust=[K1*range]−

[K2*range rate]+[K3*average range]

wherein K1, K2 and K3 are independently adjustable software constants and range rate is defined as being positive when range is decreasing and negative when range is increasing.

3. A system as set forth in claim 1, wherein:

the system can be commanded to operate in a trolling mode, said controller calculating a straight course in a desired direction and continually calculating a new anchoring site along that course or track such that the bow of the boat is forced to continuously follow that track with little or no cross-track error and wherein said remote control can be used to issue commands to increase or decrease the apparent trolling speed of the boat by having the controller displace the continuous moving anchor site an appropriate distance each computation cycle,

said remote control interface providing the operator a means of altering the trolling speed and direction.

4. A system as set forth in claim 1, wherein:

the system can be commanded to operate in a manual mode, said remote control and said controller then being used to control the direction and magnitude of the thrust from the thruster means in accordance with the boat operator'"'"'s remote control commands thus allowing the operator to move the boat under his manual control.

5. A system as set forth in claim 1, wherein:

the antenna of said DGPS or WMS enabled receiver is displaced at a known position away from the thruster means and said controller performs the necessary mathematical transformations to determine the geographic position of the point of interest based on the placement of the antenna and the GPS receiver'"'"'s information of the antenna'"'"'s geographic location.

6. A system as set forth in claims 1, wherein:

said controller can store the geographic coordinates of multiple anchoring points such that the operator of the boat can command the system to move or return the boat to any one of those stored or remembered locations.

7. A system similar to that set forth in claim 1, wherein:

one of point of interest on the boat is substantially maintained at a constant geographic location and the orientation, or heading of the boat, is also maintained at a constant angle,

a second thruster means is added specifically to provide a yaw thrust force to rotate the boat about its center of gravity in azimuth while the first thruster functions, as described in claim 1, to maintain the geographic location of the bow or other point of interest,

said controller, in addition to its functions as described in claims 1 and 2, now issues output signals to the second thruster means as required to maintain a constant boat heading thus controlling the orientation of the boat.

8. A system similar to that set forth in claim 1, wherein:

two points of interest on the boat are substantially maintained at constant geographical locations thus controlling the orientation of the boat as well as its geographic location,

said thruster means now consisting of at least two thrusters, one thruster means located at the bow, or first point of interest, and the second thruster means located at the stern, or second point of interest;

said controller now performing the necessary computations to determine the geographic location of both points of interest based on the antenna'"'"'s geographic location information received from the DGPS receiver and said controller now computing the appropriate thrust magnitudes and directions for each of the thrusters based on the two sets of ranges and range rates.

9. A system as set forth in claim 1, wherein:

said thruster means is located at the bow of the boat;

said controller modulates the magnitude of the thrust as a function of the bearing angle from the bow to the anchoring site and the thrust output signal is expressed substantially as;

thrust=[[K1*range]−

[K2*range rate]+[K3*average range]]*[1−

K4*Sine(bearing to site)]

wherein K1, K2, K3 and K4 are independently software adjustable constants and range rate is defined as being positive when range is decreasing and negative when range is increasing.

10. A system for substantially controlling the position of a boat in water at a geographic location selected by an operator of the boat, the system comprising:

a thruster attached in proximity to the bow of the boat, said thruster rotatable about an upright shaft axis and driven by a power source for producing a steering thrust vector capable of moving the boat to the selected location within the water, said thruster providing a thruster heading feedback signal equal to the relative angle between the heading of the boat and that of said thruster;

a DGPS or WAAS-enabled receiver and antenna located onboard the boat for receiving signals from GPS satellites and differential correction signals from another source, said receiver providing position information signals indicative of the position of said antenna in a differential GPS mode of operation based on said signals from the GPS satellites and the differential correction signal source;

an electronic compass for providing current heading indication signals representative of the heading of the boat;

a controller receiving input signals from said receiver, said compass and a feedback thruster steering signal equal to the relative angle between the heading of the boat and that of said thruster, said controller providing control signals to said thruster to produce the steering thrust vector for steering and propelling the boat to the selected anchoring location, the control signals based upon the range, bearing, magnitude and rate of change in range information, said control signals including a variable thrust signal whose magnitude is dependent on the direction, magnitude and rate of change in range;

a wireless manually actuated remote interface for transmitting control signals to said controller, said controller providing audible responses to inform an operator as to actions taken by said controller.

11. A system as set forth in claim 10, wherein:

the magnitude of said thrust signal is modulated to dampen the velocity of the boat as a desired position is approached based upon the range rate as modified by the yaw rate of the boat.

12. A system as set forth in claim 10, wherein:

the magnitude of said thrust signal is also based upon a long term average range error taken over an extended time period of at least about five seconds and is expressed substantially as;

thrust=[K1*range]−

[K2*range rate]+[K3average range error]

wherein K1, K2 and K3 are independently adjustable constants and range rate equals the velocity toward (+) or away from (−

) a selected location.

13. A system as set forth in claim 10, further comprising:

a non-steerable rear thruster positioned at the stern of the boat, said rear thruster producing a variable lateral or athwartship thrust responsive to a separate control signal from said controller.

14. A system as set forth in claim 10, wherein said system is programmed by said remote interface to operate in a trolling mode, said controller establishing a straight course in a desired direction along a track line and then providing control signals to said thruster to move the boat along the track line without substantial variance therefrom.

15. A system as set forth in claim 10, wherein:

said controller is programmable to receive and store multiple selected anchor locations each of which may be established by said remote interface as a desired position to which the boat will be propelled by said thruster.

16. A system as set forth in claim 10, wherein:

said controller is programmed to selectively operate said system in an anchor mode, a trolling mode or a manual mode.

17. A system for substantially establishing and controlling the position of a boat in water at a selected geographic location by an operator of the boat, the system comprising:

a thruster attached at or in close proximity to the bow of the boat, said thruster rotatable about an upright shaft axis and driven by a power source for moving the boat to a selected location within the water, said thruster providing a thruster heading feedback signal equal to the relative angle between the heading of the boat and that of said thruster;

a DGPS or WMS-enabled receiver located onboard the boat for receiving signals from GPS satellites and differential correction signals from another source, said receiver providing position information signals indicative of the position of the thruster in a differential GPS mode of operation based on said signals from the GPS satellites and the differential correction signal source;

an electronic compass for providing current heading indication signals representative of the true heading of the boat;

a controller receiving input signals from said DGPS capable receiver, said compass and a feedback thruster steering signal equal to the relative angle between the heading of the boat and that of said thruster, said controller providing control signals to said thruster for steering and propelling the boat to the selected location, the control signals based upon the range, bearing, magnitude and rate of change in range information, said control signals including a variable thrust signal whose magnitude is dependent on the direction, magnitude and rate of change in range and are expressed substantially as;

[range*K1]−

[range rate*K2]+[average range error*K3]

 

wherein K1, K2 and K3 are independently adjustable constants, range rate is the velocity toward or away from the selected location, and average range error is taken over a time period of at least five seconds;

a wireless manually actuated remote interface for transmitting control signals to said controller, said controller producing audible responses relative to action taken by said controller.

18. A system as set forth in claim 17, wherein:

said controller is programmed to selectively operate said system in an anchor mode, a trolling mode or a manual mode.

19. A system as set forth in claim 17, wherein:

the magnitude of said thrust signal is modulated to dampen the velocity of the boat as a desired position is approached based upon the range rate as modified by the yaw rate of the boat.

20. A system as set forth in claim 17, further comprising:

a non-steerable rear thruster positioned at the stern of the boat, said rear thruster producing a variable lateral or athwartship thrust responsive to a separate control signal from said controller.

21. A system as set forth in claim 17, wherein said system is programmed by said remote interface to operate in a trolling mode, said controller establishing a straight course in a desired direction along a track line and then providing control signals to said thruster to move the boat along the track line without substantial variance therefrom.

22. A system as set forth in claim 17, wherein:

said controller is programmable to receive and store multiple selected anchor locations each of which may be established by said remote interface as a desired position to which the boat will be propelled by said thruster.

23. A system for establishing and substantially controlling the position of a boat in water with respect to a geographic location selected by an operator of the boat, the system comprising:

a thruster attached in proximity to the bow of the boat, said thruster rotatable about an upright shaft axis and driven by a power source for moving the boat to a selected location within the water, said thruster providing a thruster heading feedback signal equal to the relative angle between the heading of the boat and that of said thruster;

a DGPS or WMS-enabled receiver located onboard the boat and having a signal receiving antenna spaced a substantial distance from said thruster, said receiver for receiving signals from GPS satellites and differential correction signals from another source, said receiver providing position information signals indicative of the position of the antenna in a differential GPS mode of operation based on said signals from the GPS satellites and the differential correction signal source;

an electronic compass for providing current heading indication signals representative of the true heading of the boat;

a controller receiving input signals from said receiver, said compass and a feedback thruster steering signal equal to the relative angle between the heading of the boat and that of said thruster, said controller providing control signals to said thruster for producing a steering thrust vector which steers and propels the boat to the selected geographic location, the control signals based upon the range, bearing, magnitude and rate of change in range information, said control signals including a variable thrust signal whose magnitude is dependent on the direction, magnitude and rate of change in range;

said controller programmed to modify the position information signals of said antenna by performing mathematical transformations thereon based upon the distance of said antenna from said thruster or another point of interest on or near the boat to produce a new position information signal being that of said thruster or other point of interest for use in providing the control signals;

a wireless manually actuated remote interface for transmitting control signals to said controller and for receiving audible responses relative to action taken by said controller.

24. A system as set forth in claim 23, wherein:

said controller is programmed to selectively operate said system in an anchor mode, a trolling mode or a manual mode.

25. A system as set forth in claim 23, wherein:

the magnitude of said thrust signal is modulated to dampen the velocity of the boat as a desired position is approached based upon the range rate as modified by the yaw rate of the boat.

26. A system as set forth in claim 23, wherein:

the magnitude of said thrust signal is also based upon a long term average range error taken over an extended time period of at least about five seconds and is expressed substantially as;

thrust=[K1*range]−

[K2*range rate]+[K3average range error]

wherein K1, K2 and K3 are independently adjustable constants and range rate equals the velocity toward (+) or away from (−

) a selected location.

27. A system as set forth in claim 23, further comprising:

a non-steerable rear thruster positioned at the stem of the boat, said rear thruster producing a variable lateral or athwartship thrust responsive to a separate control signal from said controller.

28. A system as set forth in claim 23, wherein said system is programmed by said remote interface to operate in a trolling mode, said controller establishing a straight course in a desired direction along a track line and then providing control signals to said thruster to move the boat along the track line without substantial variance therefrom.

29. A system as set forth in claim 23, wherein:

said controller is programmable to receive and store multiple selected anchor locations each of which may be established by said remote interface as a desired position to which the boat will be propelled by said thruster.

30. A system for substantially controlling the position of a boat in water as selected by an operator of the boat, the system comprising:

a thruster attached in proximity to the boat, said thruster rotatable about an upright shaft axis and driven by a power source for moving the boat to a selected location within the water;

a DGPS or WAAS-enabled receiver and antenna located onboard the boat for receiving signals from GPS satellites and differential correction signals from another source, said receiver providing position information signals indicative of the position of said antenna in a differential GPS mode of operation based on said signals from the GPS satellites and the differential correction signal source;

an electronic compass for providing current heading indication signals representative of the heading of the boat;

a controller receiving input signals from said receiver, said compass and a feedback thruster steering signal equal to the relative angle between the heading of the boat and that of said thruster, said controller calculating range, bearing, magnitude and rate of change in range information based upon the difference between the selected position and present position of said antenna, said controller providing control signals to said thruster for steering and propelling the boat to a selected anchoring position, the control signals being related to calculated range, bearing, magnitude and rate of change in range computations, said control signals including a variable thrust signal whose magnitude is dependent on the direction, magnitude and rate of change in range;

a wireless manually actuated remote interface for transmitting control signals to said controller, said controller providing audible responses to inform an operator as to actions taken by said controller;

said controller programmed to selectively operate said system in an anchor mode, a trolling mode or a manual mode.

31. A system as set forth in claim 30, wherein:

the magnitude of said thrust signal is modulated to dampen the velocity of the boat as a desired position is approached based upon the range rate as modified by the yaw rate of the boat.

32. A system as set forth in claim 30, wherein:

the magnitude of said thrust signal is also based upon a long term average range error taken over an extended time period of at least about five seconds and is expressed substantially as;

thrust=[K1*range]−

[K2*range rate]+[K3*average range error]

wherein K1, K2 and K3 are independently adjustable constants and range rate equals the velocity toward (+) or away from (−

) a selected location.

33. A system as set forth in claim 30, further comprising:

a non-steerable rear thruster positioned at the stern of the boat, said rear thruster producing a variable lateral or athwartship thrust responsive to a separate control signal from said controller.

34. A system as set forth in claim 30, wherein said system is programmed by said remote interface to operate in a trolling mode, said controller establishing a straight course in a desired direction along a track line and then providing control signals to said thruster to move the boat along the track line without substantial variance therefrom.

35. A system as set forth in claim 30, wherein:

said controller is programmable to receive and store multiple selected anchor locations each of which may be established by said remote interface as a desired position to which the boat will be propelled by said thruster.

36. A system for establishing and maintaining a position of a boat in water as selected by an operator of the boat, the system comprising:

two spaced apart thrusters each attached to the boat, each said thruster independently driven by a power source for moving the boat to a selected geographic location within the water;

a DGPS or WMS-enabled receiver and antenna located onboard the boat for receiving signals from GPS satellites and differential correction signals from another source, said receiver providing position information signals indicative of the position of said antenna in a differential GPS mode of operation based on said signals from the GPS satellites and the differential correction signal source;

an electronic compass for providing current heading indication signals representative of the true heading of the boat;

a controller receiving input signals from said receiver and said compass, said controller providing control signals to each said thruster for producing a net steering thrust vector which steers and propels the boat to the selected geographic location, the control signals based upon the range, bearing, magnitude and rate of change in range information, said control signals including a variable thrust signal whose magnitude is dependent on the direction, magnitude and rate of change in range;

a wireless manually actuated remote interface for transmitting control signals to said controller, said controller providing audible responses to advise an operator as to actions taken by said controller.

37. A system as set forth in claim 36, wherein:

said thrusters are non-rotatable about an upright axis thereof.

38. A system as set forth in claim 37, wherein:

each of said thrusters is oriented to produce only either a forward or rearward thrust generally in alignment with the length of the boat.

39. A system as set forth in claim 37, wherein:

one said thruster is positioned at or in close proximity to the bow of the boat and produces only a forward or a rearward thrust generally in alignment with the length of the boat;

another said thruster is positioned at or in close proximity to the stern of the boat and produces only a lateral or athwartship thrust with respect to the boat.

40. A system as set forth in claim 36, wherein:

one said thruster is positioned at or in close proximity to the bow of the boat and is rotatable about an upright axis thereof;

another said thruster is positioned at or in close proximity to the stem of the boat and produces only a lateral or athwartship thrust with respect to the boat.

41. A system for establishing and maintaining a position of a boat in water at a geographic location selected by an operator of the boat, the system comprising:

two spaced apart thrusters each attached to the boat, each said thruster independently driven by a power source for moving the boat to the selected geographic location within the water;

a DGPS or WMS-enabled receiver and antenna located onboard the boat for receiving signals from GPS satellites and differential correction signals from another source, said receiver providing position information signals indicative of the position of said antenna in a differential GPS mode of operation based on said signals from the GPS satellites and the differential correction signal source;

an electronic compass for providing current heading indication signals representative of the true heading of the boat;

a controller receiving input signals from said receiver and said compass, said controller providing control signals to each said thruster for producing a net steering thrust vector which steers and propels the boat to the selected geographic location and for maintaining a selected orientation of the longitudinal axis of the boat with respect to the selected geographic location, the control signals based upon the range, bearing, magnitude and rate of change in range information, said control signals including a variable thrust signal whose magnitude is dependent on the direction, magnitude and rate of change in range;

a wireless manually actuated remote interface for transmitting control signals to said controller, said controller providing audible responses to advise an operator as to actions taken by said controller.

42. A system as set forth in claim 41, wherein:

said thrusters are non-rotatable about an upright axis thereof.

43. A system as set forth in claim 42, wherein:

each of said thrusters is oriented to produce only either a forward or rearward thrust generally in alignment with the length of the boat.

44. A system as set forth in claim 42, wherein:

one said thruster is positioned at or in close proximity to the bow of the boat and produces only a forward or a rearward thrust generally in alignment with the length of the boat;

another said thruster is positioned at or in close proximity to the stern of the boat and produces only a lateral or athwartship thrust with respect to the boat.

45. A system as set forth in claim 41, wherein:

one said thruster is positioned at or in close proximity to the bow of the boat and is rotatable about an upright axis thereof;

another said thruster is positioned at or in close proximity to the stern of the boat and produces only a lateral or athwartship thrust with respect to the boat.

46. A system for establishing and maintaining a position of a boat in water as selected by an operator of the boat, the system comprising:

two spaced apart thrusters each attached to the boat, each said thruster independently driven by a power source for moving the boat to a first selected geographic location within the water;

a DGPS or WAAS-enabled receiver and antenna located onboard the boat for receiving signals from GPS satellites and differential correction signals from another source, said receiver providing position information signals indicative of the position of said antenna in a differential GPS mode of operation based on said signals from the GPS satellites and the differential correction signal source;

an electronic compass for providing current heading indication signals representative of the true heading of the boat;

a controller receiving input signals from said receiver and said compass;

said controller programmed to modify the position information signals of said antenna by performing a mathematical transformation thereon based upon the distance of said antenna from another point of interest on or near the boat to produce a second position information signal being that of the other point of interest for use in providing the control signals;

said controller providing control signals to each said thruster for producing a net steering thrust vector which steers and propels the boat to position the antenna at the first selected geographic location and to also position the other point of interest at the second selected geographic location, the control signals based upon the range, bearing, magnitude and rate of change in range information, said control signals including a variable thrust signal whose magnitude is dependent on the direction, magnitude and rate of change in range;

a wireless manually actuated remote interface for transmitting control signals to said controller, said controller providing audible responses to advise an operator as to actions taken by said controller.

47. A system as set forth in claim 46, wherein:

said thrusters are non-rotatable about an upright axis thereof.

48. A system as set forth in claim 47, wherein:

each of said thrusters is oriented to produce only either a forward or rearward thrust generally in alignment with the length of the boat.

49. A system as set forth in claim 47, wherein:

one said thruster is positioned at or in close proximity to the bow of the boat and produces only a forward or a rearward thrust generally in alignment with the length of the boat;

another said thruster is positioned at or in close proximity to the stem of the boat and produces only a lateral or athwartship thrust with respect to the boat.

50. A system as set forth in claim 46, wherein:

one said thruster is positioned at or in close proximity to the bow of the boat and is rotatable about an upright axis thereof;

another said thruster is positioned at or in close proximity to the stern of the boat and produces only a lateral or athwartship thrust with respect to the boat.