Method of steering aquatic vessels

• US 20080171479A1
• Filed: 09/14/2007
• Published: 07/17/2008
• Est. Priority Date: 01/16/2007
• Status: Active Grant

• Current Assignee: AB Volvo
• Original Assignee: AB Volvo
• Inventors: Hallenstvedt, Oddbjorn, Larsson, Anders L.
• Granted Patent: US 8,060,265 B2
• Time in Patent Office: Days
• US Class Current: 440/1
• CPC Class Codes: B63H 21/22 the propulsion power units being controlled from exterior of engine room, e.g. from navigation bridge; Arrangements of order telegraphs
• 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: B63H 5/10 of coaxial type, e.g. of counter-rotative type
• CPC Class Codes: B63H 5/125 movably mounted with respect to hull, e.g. adjustable in direction , e.g. podded azimuthing thrustersoutboard units or Z-drives B63H20/00; movably mounted for steering purposes only, rudders carrying propellers B63H25/42

Abstract

There is provided a boat (200) including a hull (20), and two engines (30, 50) couplable to rotationally drive mutually spaced separate corresponding propeller assemblies for providing thrusts. Directions of the thrusts are angularly adjustable (α₁, α₂) relative to the hull (20). A control unit (70) receives first and second user commands (S₁, S₂) and sends corresponding signals for controlling powers (P1, P2) coupled from the engines (30, 50) to their propeller assemblies. The control unit (70) determines a difference in power (ΔP) to be coupled to the propeller assemblies as a function of the first and second user commands (S₁, S₂). The control unit (70) controls coupling of power (P1, P2) to the propeller assemblies so that the propeller assemblies develop a difference in thrust which is a function of the difference in power (ΔP). The control unit (70) adjusts angles (α₁, α₂) of the directions of thrusts as a function of the difference in power (ΔP) to assist the difference in power (ΔP) coupled to the propeller assemblies to enhance maneuverability of the vessel (200).

Claims

1. A method of steering an aquatic vessel having at least one hull, at least one engine couplable to rotationally drive a plurality of mutually spaced separate corresponding propeller assemblies for providing thrusts to propel the vessel through water, wherein directions of said thrusts developed by said plurality of the propeller assemblies are angularly adjustable relative to the at least one hull, and wherein the vessel further includes a control unit for receiving user commands and for sending corresponding signals for controlling power coupled from said at least one engine to said propeller assemblies, said method comprising the steps of:

receiving at least first and second user commands at the control unit;

responsive to receiving said at least first and second user commands, determining a difference in power to be coupled from said at least one engine to said plurality of propeller assemblies as a function of said first and second user commands;

coupling power to said plurality of propeller assemblies in response to said at least first and second user commands so that said plurality of propeller assemblies develop a difference in thrust which is a function of said difference in power; and

adjusting angles of said directions of thrusts as a function of said difference in power coupled to said plurality of propeller assemblies to enhance maneuverability of said vessel in operation.

2. A method as claimed in claim 1, further comprising the step of controlling said angles of said plurality of mutually spaced separated propeller assemblies so as to develop the associated thrusts along corresponding directions which are mutually substantially parallel.

3. A method as claimed in claim 2, further comprising the step of applying an angular correction when controlling said angles, said angular correction being a function of said angles and a speed of said vessel in water.

4. A method as claimed in claim 1, wherein the step of adjusting said angles of said directions of thrust as a function of said difference in power coupled to said plurality of propeller assemblies is determined as at least one of a linear function, a polynomial function, a logarithmic function, and an exponential function.

5. A method as claimed in claim 1, further comprising the step of receiving at said control unit a user command selecting a function for setting said angles of said directions of thrust relative to said difference in power coupled to said plurality of propeller assemblies.

6. A method as claimed in claim 1, wherein the first and second user commands are generated responsive to user manipulation of a pair of mutually independently adjustable controls.

7. A method as claimed in claim 6, wherein the pair of mutually adjustable controls comprises two independently adjustable levers, wherein the two user commands are a function of relative positions of the levers.

8. A method as claimed in claim 1, wherein, the first and second user commands are generated in response to user manipulation of a single control having at least two mutually independently adjustable degrees of freedom.

9. A method as claims in claim 8, wherein the single control is a joystick.

10. A method as claimed in claim 1, further comprising the step of implementing the control unit by at least one of:

computer hardware operable to execute a software product, mechanical logic, hydraulic logic.

11. A method as claimed in claim 1, further comprising the step of receiving a user command for operating the control unit in one of a conventional mode of steering the vessel and a method as claimed in claim 1.

12. An aquatic vessel comprising:

at least one hull,

at least one engine couplable to rotationally drive a plurality of mutually spaced separate propeller assemblies for providing thrusts to propel the vessel through water, wherein directions of said thrusts developed by said plurality of the propeller assemblies are angularly adjustable relative to the at least one hull,

a control unit for receiving user commands and for sending corresponding signals for controlling power coupled from said at least one engine to said propeller assemblies,

said control unit being configured to receive at least first and second user commands;

said control unit including means for determining a difference in power to be provided to said plurality of propeller assemblies as a function of said first and second user commands;

said control unit being configured to control coupling of power to said plurality of propeller assemblies responsive to said at least first and second user commands so that said plurality of propeller assemblies develop a difference in thrust which is a function of said difference in power; and

said control unit being configured to adjust angles of said directions of thrusts as a function of said difference in power.

13. A vessel as claimed in claim 12, wherein the control unit is configured to control said angles of said plurality of mutually spaced separated propeller assemblies so as to develop their thrust directions which are mutually substantially parallel.

14. A vessel as claimed in claim 12, wherein said control unit is configured to apply an angular correction when controlling said angles, said angular correction being a function of said angles and a speed of said vessel in water.

15. A vessel as claimed in claim 12, wherein said function relating said difference in power with said angles of said thrusts of said propeller assemblies relative to said at least one hull includes at least one of:

a linear function, a polynomial function, a logarithmic function, an exponential function.

16. A vessel as claimed in claim 12, further comprising a selector associated with said control unit for selecting a function relating said difference in power with said angles of thrusts developed by said propeller assemblies.

17. A vessel as claimed in claim 12, wherein at least one of said plurality of propeller assemblies includes a mutually counter-rotating pair of propellers.

18. A vessel as claimed in claim 12, wherein at least one of the propeller assemblies is pivotally mounted with respect to said at least one hull.

19. A vessel as claimed in claim 18, wherein said at least one of the propeller assemblies is pivotally servo-actuated in response to signals provided from said control unit.

20. A vessel as claimed in claims 12, comprising a pair of mutually independently adjustable control for generating the first and second user commands.

21. A vessel as claimed in claim 20, wherein the pair of mutually adjustable controls comprise two independently adjustable levers, wherein first and second commands are a function of relative positions of the levers.

22. A vessel as claimed in claim 12, comprising a single control having at least two mutually independently adjustable degrees of freedom for generating the first and second user commands.

23. A vessel as claimed in claim 22, wherein the single control is a joystick controller.

24. A vessel as claimed in claim 12, wherein the control unit comprises at least one of computer hardware operable to execute a software product, mechanical logic, and hydraulic logic.

25. A vessel as claimed in claim 12, wherein the control unit includes means for switching between a conventional mode of steering the vessel and a mode of steering wherein the angles of thrust and the difference in power are controlled in combination.

26. A software product stored on a data carrier or conveyed via a signal, said software product being executable on computing hardware for implementing a method as claimed in 1.