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Title:
LAUNCH AND RECOVERY SYSTEM AND METHOD
Document Type and Number:
WIPO Patent Application WO/2015/049679
Kind Code:
A1
Abstract:
An underwater launch and recovery system is disclosed including: a surface water vehicle; at least one underwater vehicle; a docking system for selectively docking and undocking each underwater vehicle with respect to the surface vehicle at a selectively controllable water depth. The docking system includes a docking port for enabling the underwater vehicle to be selectively engaged and disengaged with respect to the docking system, the docking port being connected to the surface water vehicle via a movable connector. The movable connector is configured for: providing a predetermined said water depth to said docking port for enabling said selectively docking and undocking, and for decoupling at least surface heave movement of surface water vehicle from underwater heave movement of the docking port at said predetermined water depth. Also disclosed are methods for underwater launch and recovery.

Inventors:
SIMHONY SHIMON (IL)
Application Number:
PCT/IL2014/050856
Publication Date:
April 09, 2015
Filing Date:
September 29, 2014
Export Citation:
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Assignee:
ISRAEL AEROSPACE IND LTD (IL)
International Classes:
B60B23/00; B60B21/00; B63B27/36
Domestic Patent References:
WO2013017414A12013-02-07
Foreign References:
US3943875A1976-03-16
EP2452869A12012-05-16
US20100192831A12010-08-05
US4072123A1978-02-07
US20120227654A12012-09-13
US7699015B12010-04-20
US4304189A1981-12-08
US4516517A1985-05-14
Attorney, Agent or Firm:
SERUYA, Yehuda (P.O.B. 13239, 62 Tel-Aviv, IL)
Download PDF:
Claims:
CLAIMS:

1. An underwater launch and recovery system, comprising:

a surface water vehicle;

at least one underwater vehicle;

a docking system for selectively docking and undocking each said underwater vehicle with respect to the surface vehicle at a selectively controllable water depth, the docking system comprising a docking port for enabling said underwater vehicle to be selectively engaged and disengaged with respect to the docking system, wherein the docking port is connected to the surface water vehicle via a movable connector;

wherein the movable connector is configured for:

providing a predetermined said water depth to said docking port for enabling said selectively docking and undocking, and

decoupling at least surface heave movement of surface water vehicle from underwater heave movement of the docking port at said predetermined water depth.

2. The underwater launch and recovery system according to claim 1, where said predetermined water depth is chosen to provide underwater heave of the underwater vehicle within a predetermined threshold.

3. The underwater launch and recovery system according to any one of claims 1 to

2, wherein said underwater vehicle is any one of an underwater remotely piloted vehicle, an underwater autonomous vehicle and an underwater unmanned towed vehicle.

4. The underwater launch and recovery system according to any one of claims 1 to

3, wherein said surface vehicle comprises any one of a single hull surface vehicle, a multi hull surface vehicle, a hovercraft, a hydrofoil, a submersible vehicle, or a catamaran type surface vehicle, comprising a pair of hulls laterally spaced via a raised deck.

5. The underwater launch and recovery system according to any one of claims 1 to

4, wherein said surface vehicle is connected to the underwater vehicle via a tether, and wherein said tether provides at least one of power transmission and data communication between said surface vehicle and said underwater vehicle.

6. The underwater launch and recovery system according to any one of claims 1 to 5, wherein said movable connector comprises a connector arm and a joint arrangement, said connector arm comprising a first arm end connected to the joint arrangement, and a second arm end connected to said docking port, and wherein said joint arrangement is configured for:

enabling selectively providing said predetermined water depth to said docking port via said connector arm, and

decoupling at least said underwater heave movement of the docking port from surface heave movement of surface water vehicle at said predetermined water depth via said connector arm.

7. The underwater launch and recovery system according to claim 6, wherein said joint arrangement connects said first arm end to said surface vehicle, and is configured for allowing pivoting movement between said first arm end and said surface vehicle in at least one degree of freedom in rotation, wherein said at least one degree of freedom in rotation includes at least one of pitch, roll and yaw.

8. The underwater launch and recovery system according to any one of claims 6 to 7, wherein said joint arrangement comprises a passive flexible joint allowing free said pivoting movement between said first arm end and said surface vehicle.

9. The underwater launch and recovery system according to claim 8, wherein said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body, or wherein said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

10. The underwater launch and recovery system according to any one of claims 8 to 9, wherein in operation of the underwater launch and recovery system for launching or recovering the underwater vehicle, the surface vehicle is caused to move with a forward velocity while the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle, wherein at said forward velocity, a tension and a drag are induced in the connector arm.

11. The underwater launch and recovery system according to any one of claims 6 to 7, wherein said joint arrangement comprises an active flexible joint arrangement configured for selectively and actively controlling said pivoting movement between said first arm end and said surface vehicle, wherein the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle, a roll angle and a yaw angle.

12. The underwater launch and recovery system according to claim 11, comprising an inertial control system for providing control inputs regarding the spatial position and attitude of the docking port, and wherein said passive flexible joint comprises a motorized articulated joint arrangement for controllably varying at least one of said pitch angle, roll angle, and yaw angle, responsive to said control inputs, wherein said inertial control comprises inertial sensors for sensing pivoting movement of the docking port about respective pitch, yaw and roll axes, and for sensing accelerations of the docking port along said respective pitch, yaw and roll axes.

13. The underwater launch and recovery system according to any one of claims 11 to 12, wherein said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body, or, wherein said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

14. The underwater launch and recovery system according to any one of claims 6 to 13, wherein said connector arm is selectively movable between a stowed position and a deployed position, wherein in the stowed position the docking port is immovably engaged to the surface vehicle, and wherein in the deployed position the connector arm is at least partially submerged to: provide said predetermined water depth to said docking port via said connector arm, and

to allow decoupling of at least said underwater heave movement of the docking port from surface heave movement of surface water vehicle at said predetermined water depth via said connector arm.

15. The underwater launch and recovery system according to any one of claims 1 to 14, wherein the movable connector is configured for decoupling surface pitch, roll and yaw movements of surface water vehicle from the docking port from at said predetermined water depth.

16. A docking system for selectively docking and undocking an underwater vehicle with respect to a surface water vehicle at a selectively controllable water depth, the docking system comprising:

a docking port connected to a movable connector,

said docking port being configured for enabling said underwater vehicle to be selectively engaged and disengaged with respect to the docking system;

said movable connector being configured for being mounted to the surface water vehicle;

the movable connector being further configured for:

providing a predetermined said water depth to said docking port for enabling said selectively docking and undocking, and

decoupling at least surface heave movement of surface water vehicle from underwater heave movement of the docking port at said predetermined water depth.

17. The docking system according to claim 16, wherein said movable connector comprises a connector arm and a joint arrangement, said connector arm comprising a first arm end connected to the joint arrangement, and a second arm end connected to said docking port, and wherein said joint arrangement is configured for:

enabling selectively providing said predetermined water depth to said docking port via said connector arm, and

decoupling at least said underwater heave movement of the docking port from surface heave movement of the surface water vehicle at said predetermined water depth via said connector arm.

18. The docking system according to any one of claims 16 to 17, wherein said joint arrangement is configured for connecting said first arm end to said surface vehicle, and is configured for allowing pivoting movement between said first arm end and the surface water vehicle in at least one degree of freedom in rotation.

19. The docking system according to claim 18, wherein said at least one degree of freedom in rotation includes at least one of pitch, yaw and roll.

20. The docking system according to any one of claims 17 to 19, wherein said joint arrangement comprises passive flexible joint allowing free said pivoting movement between said first arm end and said surface vehicle.

21. The docking system according to claim 20, wherein said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body, or, wherein said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

22. The docking system according to any one of claims 20 to 21, wherein in operation of the underwater launch and recovery system for launching or recovering the underwater vehicle, the surface vehicle is caused to move with a forward velocity while the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle.

23. The docking system according to claim 22, wherein at said forward velocity, a tension and a drag are induced in the connector arm, and wherein, the tension balances the weight and drag of the arm, thereby maintaining the depth and spatial orientation of the docking port stable.

24. The docking system according to any one of claims 17 to 19, wherein said joint arrangement comprises an active flexible joint arrangement configured for selectively and actively controlling said pivoting movement between said first arm end and said surface vehicle.

25. The docking system according to claim 24, wherein the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle, a roll angle and a yaw angle.

26. The docking system according to claim 25, comprising an inertial control system for providing control inputs regarding the spatial position and attitude of the docking port, and wherein said passive flexible joint comprises a motorized articulated joint arrangement for controllably varying at least one of said pitch angle, roll angle, and yaw angle, responsive to said control inputs, and wherein said inertial control comprises inertial sensors for sensing pivoting movement of the docking port about respective pitch, yaw and roll axes, and for sensing accelerations of the docking port along said respective pitch, yaw and roll axes.

27. The docking system according to any one of claims 24 to 26, wherein said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body, or, wherein said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

28. The docking system according to any one of claims 17 to 27, wherein said connector arm is selectively movable between a stowed position and a deployed position, wherein in the stowed position the docking port is immovably engaged to the surface vehicle, and wherein in the deployed position the connector arm is at least partially submerged to:

provide said predetermined water depth to said docking port via said connector arm, and

to allow decoupling of at least said underwater heave movement of the docking port from surface heave movement of the surface water vehicle at said predetermined water depth via said connector arm.

29. The docking system according to any one of claims 16 to 28, wherein the movable connector is configured for decoupling surface pitch, roll and yaw movements of surface water vehicle from the docking port from at said predetermined water depth.

30. A surface water vehicle comprising the docking system as defined in any one of claims 16 to 29.

31. An underwater launch and recovery method, comprising:

providing the underwater launch and recovery system as defined in any one of claims 1 to 15;

operating the underwater launch and recovery system to launch or recover the at least one said underwater vehicle with respect to the surface vehicle.

32. An underwater launch and recovery method, comprising:

providing a surface water vehicle;

providing at least one underwater vehicle;

providing a docking system for selectively docking and undocking each said underwater vehicle with respect to the surface vehicle at a selectively controllable water depth, the docking system comprising a docking port selectively engageable and disengageable with respect to the underwater vehicle, wherein the docking port is connected to the surface water vehicle via a movable connector;

providing a predetermined said water depth to said docking port via said movable connector for enabling said selectively docking and undocking, and

decoupling at least surface heave movement of surface water vehicle from underwater heave movement of the docking port at said predetermined water depth via said movable connector.

33. The underwater launch and recovery method according to claim 31 or claim 32, comprising choosing said predetermined water depth to provide underwater heave of the underwater vehicle within a predetermined threshold.

34. The underwater launch and recovery method according to any one of claims 31 to 33, wherein said underwater vehicle is any one of an underwater remotely piloted vehicle, an underwater autonomous vehicle and an underwater unmanned towed vehicle, and wherein said surface vehicle comprises any one of a single hull surface vehicle, a multi hull surface vehicle, a hovercraft, a hydrofoil, a submersible vehicle and catamaran type surface vehicle.

35. The underwater launch and recovery method according to any one of claims 31 to 34, wherein at least during operation of said underwater vehicle, said surface vehicle is connected to said underwater vehicle via a tether.

36. The underwater launch and recovery method according to claim 35, comprising providing at least one of power and data communication between said surface vehicle and said underwater vehicle at least during operation of the underwater vehicle..

37. The underwater launch and recovery method according to any one of claims 31 to 36, wherein said movable connector comprises a connector arm and a joint arrangement, said connector arm comprising a first arm end connected to the joint arrangement, and a second arm end connected to said docking port, and wherein said joint arrangement is configured for:

enabling selectively providing said predetermined water depth to said docking port via said connector arm, and

decoupling at least said underwater heave movement of the docking port from surface heave movement of surface water vehicle at said predetermined water depth via said connector arm.

38. The underwater launch and recovery method according to claim 37, comprising allowing pivoting movement between said first arm end and said surface vehicle in at least one degree of freedom in rotation at least during docking or undocking operation between the underwater vehicle and the docking port.

39. The underwater launch and recovery method according to claim 38, wherein said at least one degree of freedom in rotation includes pitch.

40. The underwater launch and recovery method according to any one of claims 37 to 39, comprising allowing free said pivoting movement between said first arm end and said surface vehicle.

41. The underwater launch and recovery method according to claim 40, wherein said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body.

42. The underwater launch and recovery method according to claim 40, wherein said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

43. The underwater launch and recovery method according to any one of claims 40 to 42, comprising causing the surface vehicle to move with a forward velocity while the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle.

44. The underwater launch and recovery method according to claim 43, wherein at said forward velocity, a tension and a drag are induced in the connector arm.

45. The underwater launch and recovery method according to claim 44, wherein the forward velocity is chosen such that the tension balances the weight and drag of the arm, thereby maintaining the depth of the docking port at said predetermined water depth stable, and the spatial orientation of the docking port stable.

46. The underwater launch and recovery method according to any one of claims 37 to 39, comprising selectively and actively controlling said pivoting movement between said first arm end and said surface vehicle.

47. The underwater launch and recovery method according to claim 46, wherein the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle, a roll angle and a yaw angle.

48. The underwater launch and recovery method according to claim 47, comprising providing control inputs regarding the spatial position and attitude of the docking port, and controllably varying at least one of said pitch angle, roll angle, and yaw angle, responsive to said control inputs.

49. The underwater launch and recovery method according to claim 48, comprising sensing pivoting movement of the docking port about respective pitch, yaw and roll axes, and sensing accelerations of the docking port along said respective pitch, yaw and roll axes, to provide said control inputs.

50. The underwater launch and recovery method according to any one of claims 31 to 49, comprising decoupling surface pitch, roll and yaw movements of surface water vehicle from the docking port at said predetermined water depth.

Description:
LAUNCH AND RECOVERY SYSTEM AND METHOD

TECHNOLOGICAL FIELD

The presently disclosed subject matter relates to systems and methods for launching and recovering underwater vehicles.

PRIOR ART

References considered to be relevant as background to the presently disclosed subject matter are listed below:

- US 3,807,335

- US 7,350,475

- US 7,028,627

- US 8,096,254

- US 5,995,882

- US 6,779,475

- US 7,156,036

- US 7,581,507

- US 7,712,429

- US 7,546,814

- US 2006/0254491

- US 2007/0137548

- US 2012/0192780

- US 2013/0025521

Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter. BACKGROUND

Underwater vehicles have a variety of uses, including for example mine hunting. Some types of such underwater vehicles are launched and recovered by a host surface ship, and launch and recovery systems for such underwater vehicles are known. Conventionally, such systems can only be used safely in calm waters, often require skilled manpower for operating the system, and the systems can often represent a significant capital cost, and corresponding high operating costs.

GENERAL DESCRIPTION

According to at least a first aspect of the presently disclosed subject matter, there is provided an underwater launch and recovery system, comprising:

a surface water vehicle;

at least one underwater vehicle;

a docking system for selectively docking and undocking each said underwater vehicle with respect to the surface vehicle at a selectively controllable water depth, the docking system comprising a docking port for enabling said underwater vehicle to be selectively engaged and disengaged with respect to the docking system (for example docking port is selectively engageable and disengageable with respect to a docking interface that is mounted in or otherwise comprised in the at least one underwater vehicle), wherein the docking port is connected to the surface water vehicle via a movable connector;

wherein the movable connector is configured for:

providing a predetermined said water depth to said docking port for enabling said selectively docking and undocking, and

decoupling at least surface heave movement of surface water vehicle from underwater heave movement of the docking port at said predetermined water depth.

Optionally, said predetermined water depth is chosen to provide underwater heave of the underwater vehicle within a predetermined threshold; for example, said predetermined threshold is less than 10cm. For example, said predetermined water depth is greater than 5m, or greater than 6m, or greater than 7m, or greater than 8m, or greater than 9m, or greater than 10m.

Additionally or alternatively, said underwater vehicle is any one of an underwater remotely piloted vehicle, an underwater autonomous vehicle and an underwater unmanned towed vehicle.

Additionally or alternatively, said surface vehicle comprises any one of a single hull surface vehicle, a multi hull vehicle for example a twin hull surface vehicle, a hovercraft, a hydrofoil, a submersible vehicle.

Additionally or alternatively, said surface vehicle comprises catamaran type surface vehicle, comprising a pair of hulls laterally spaced via a raised deck.

Additionally or alternatively, said surface vehicle is connected to the underwater vehicle via a tether. For example, said tether provides at least one of power communication and data communication between said surface vehicle and said underwater vehicle.

Additionally or alternatively, said movable connector comprises a connector arm and a joint arrangement, said connector arm comprising a first arm end connected to the joint arrangement, and a second arm end connected to said docking port, and wherein said joint arrangement is configured for:

enabling selectively providing said predetermined water depth to said docking port via said connector arm, and

decoupling at least said underwater heave movement of the docking port from surface heave movement of surface water vehicle at said predetermined water depth via said connector arm.

For example, said connector arm and said joint arrangement comprise a lumen. Additionally or alternatively, said joint arrangement connects said first arm end to said surface vehicle, and is configured for allowing pivoting movement between said first arm end and said surface vehicle in at least one degree of freedom in rotation. For example, said at least one degree of freedom in rotation includes pitch and/or roll and/or yaw.

Additionally or alternatively, in at least one example said joint arrangement comprises passive flexible joint allowing free said pivoting movement between said first arm end and said surface vehicle. For example said passive flexible joint comprises an articulated joint. Additionally or alternatively, for example, said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body; alternatively, for example, said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body. Additionally or alternatively, in operation of the underwater launch and recovery system for launching or recovering the underwater vehicle, the surface vehicle is caused to move with a forward velocity while the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle. For example, at said forward velocity, a tension and a drag are induced in the connector arm; for example, the tension balances the weight and drag of the arm, thereby maintaining the depth and spatial orientation of the docking port stable.

Additionally or alternatively in at least another example, said joint arrangement comprises an active flexible joint arrangement configured for selectively and actively controlling said pivoting movement between said first arm end and said surface vehicle. For example, the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle, a roll angle and a yaw angle. For example, the underwater launch and recovery system comprises an inertial control system for providing control inputs regarding the spatial position and attitude of the docking port, and wherein said passive flexible joint comprises a motorized articulated joint arrangement for controllably varying at least one of said pitch angle, roll angle, and yaw angle, responsive to said control inputs. For example, said inertial control comprises inertial sensors for sensing pivoting movement of the docking port about respective pitch, yaw and roll axes, and for sensing accelerations of the docking port along said respective pitch, yaw and roll axes. Additionally or alternatively, for example, said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body; alternatively, for example, said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

Additionally or alternatively, said connector arm is selectively movable between a stowed position and a deployed position, wherein in the stowed position the docking port is immovably engaged to the surface vehicle, and wherein in the deployed position the connector arm is at least partially submerged to:

provide said predetermined water depth to said docking port via said connector arm, and

to allow decoupling of at least said underwater heave movement of the docking port from surface heave movement of surface water vehicle at said predetermined water depth via said connector arm.

Additionally or alternatively, the movable connector is configured for decoupling surface pitch and/or roll and/or yaw movements of surface water vehicle from the docking port from at said predetermined water depth.

According to this aspect of the presently disclosed subject matter, there is also provided an underwater launch and recovery method, comprising:

providing the underwater launch and recovery system as defined herein, in particular as defined above;

operating the underwater launch and recovery system to launch or recover the at least one said underwater vehicle with respect to the surface vehicle.

According to at least a second aspect of the presently disclosed subject matter, there is provided a docking system for selectively docking and undocking an underwater vehicle with respect to a surface water vehicle at a selectively controllable water depth, the docking system comprising:

a docking port connected to a movable connector,

said docking port being configured for enabling said underwater vehicle to be selectively engaged and disengaged with respect to the docking system; said movable connector being configured for being mounted to the surface water vehicle; the movable connector being further configured for:

providing a predetermined said water depth to said docking port for enabling said selectively docking and undocking, and

decoupling at least surface heave movement of surface water vehicle from underwater heave movement of the docking port at said predetermined water depth.

Optionally, said predetermined water depth is chosen to provide underwater heave of the underwater vehicle within a predetermined threshold; for example, said predetermined threshold is less than 10cm.

For example, said predetermined water depth is greater than 5m, or greater than 6m, or greater than 7m, or greater than 8m, or greater than 9m, or greater than 10m.

For example, said movable connector comprises a connector arm and a joint arrangement, said connector arm comprising a first arm end connected to the joint arrangement, and a second arm end connected to said docking port, and wherein said joint arrangement is configured for:

enabling selectively providing said predetermined water depth to said docking port via said connector arm, and

decoupling at least said underwater heave movement of the docking port from surface heave movement of the surface water vehicle at said predetermined water depth via said connector arm.

For example, said connector arm and said joint arrangement comprise a lumen.

For example, said joint arrangement is configured for connecting said first arm end to said surface vehicle, and is configured for allowing pivoting movement between said first arm end and the surface water vehicle in at least one degree of freedom in rotation. For example, said at least one degree of freedom in rotation includes pitch and/or roll and/or yaw.

Additionally or alternatively, for example, said joint arrangement comprises passive flexible joint allowing free said pivoting movement between said first arm end and said surface vehicle. For example, said passive flexible joint comprises an articulated joint. For example, said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body. Alternatively, for example, said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

Additionally or alternatively, for example, in operation of an underwater launch and recovery system for launching or recovering the underwater vehicle using said docking system, the surface vehicle is caused to move with a forward velocity while the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle. For example, at said forward velocity, a tension and a drag are induced in the connector arm. For example, the tension balances the weight and drag of the arm, thereby maintaining the depth and spatial orientation of the docking port stable.

Alternatively, for example, said joint arrangement comprises an active flexible joint arrangement configured for selectively and actively controlling said pivoting movement between said first arm end and said surface vehicle. For example, the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle, a roll angle and a yaw angle. For example, the docking system comprises an inertial control system for providing control inputs regarding the spatial position and attitude of the docking port, and wherein said passive flexible joint comprises a motorized articulated joint arrangement for controllably varying at least one of said pitch angle, roll angle, and yaw angle, responsive to said control inputs. For example, said inertial control comprises inertial sensors for sensing pivoting movement of the docking port about respective pitch, yaw and roll axes, and for sensing accelerations of the docking port along said respective pitch, yaw and roll axes.

Additionally or alternatively, for example, said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body. Alternatively, for example, said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

Additionally or alternatively, for example, said connector arm is selectively movable between a stowed position and a deployed position, wherein in the stowed position the docking port is immovably engaged to the surface vehicle, and wherein in the deployed position the connector arm is at least partially submerged to:

provide said predetermined water depth to said docking port via said connector arm, and

to allow decoupling of at least said underwater heave movement of the docking port from surface heave movement of the surface water vehicle at said predetermined water depth via said connector arm.

Additionally or alternatively, for example, the movable connector is configured for decoupling surface pitch, roll and yaw movements of surface water vehicle from the docking port from at said predetermined water depth.

According to at least the second aspect of the presently disclosed subject matter, there is provided a surface water vehicle comprising the docking system as defined herein, in particular above for the second aspect of the presently disclosed subject matter.

According to at least a third aspect of the presently disclosed subject matter, there is provided an underwater launch and recovery method, comprising:

providing a surface water vehicle;

providing at least one underwater vehicle;

providing a docking system for selectively docking and undocking each said underwater vehicle with respect to the surface vehicle at a selectively controllable water depth, the docking system comprising a docking port selectively engageable and disengageable with respect to the at least one underwater vehicle (for example the docking port is selectively engageable and disengageable with respect to a docking interface mounted to or otherwise comprised in the at least one underwater vehicle), wherein the docking port is connected to the surface water vehicle via a movable connector;

providing a predetermined said water depth to said docking port via said movable connector for enabling said selectively docking and undocking, and decoupling at least surface heave movement of surface water vehicle from underwater heave movement of the docking port at said predetermined water depth via said movable connector.

For example, the underwater launch and recovery method comprises choosing said predetermined water depth to provide underwater heave of the underwater vehicle within a predetermined threshold; for example said predetermined threshold is less than 10cm.

Additionally or alternatively, said underwater vehicle is any one of an underwater remotely piloted vehicle, an underwater autonomous vehicle and an underwater unmanned towed vehicle, and wherein said surface vehicle comprises any one of a single hull surface vehicle, a twin hull surface vehicle, a hovercraft, a hydrofoil, a submersible vehicle.

Additionally or alternatively, at least during operation of said underwater vehicle, said surface vehicle is connected to said underwater vehicle via a tether. For example, the underwater launch and recovery method comprises providing at least one of power and data communication between said surface vehicle and said underwater vehicle at least during operation of the underwater vehicle.

Additionally or alternatively, said movable connector comprises a connector arm and a joint arrangement, said connector arm comprising a first arm end connected to the joint arrangement, and a second arm end connected to said docking port, and wherein said joint arrangement is configured for:

enabling selectively providing said predetermined water depth to said docking port via said connector arm, and

decoupling at least said underwater heave movement of the docking port from surface heave movement of surface water vehicle at said predetermined water depth via said connector arm.

For example, the underwater launch and recovery method comprises allowing pivoting movement between said first arm end and said surface vehicle in at least one degree of freedom in rotation at least during docking or undocking operation between the underwater vehicle and the docking port. For example said at least one degree of freedom in rotation includes pitch and/or roll and/or yaw. Additionally or alternatively, in at least one example, the underwater launch and recovery method comprises allowing free said pivoting movement between said first arm end and said surface vehicle. For example, said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body; or for example said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body. Additionally or alternatively, for example, the underwater launch and recovery method comprises causing the surface vehicle to move with a forward velocity while the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle. For example, at said forward velocity, a tension and a drag are induced in the connector arm. For example, the forward velocity is chosen such that the tension balances the weight and drag of the arm, thereby maintaining the depth of the docking port at said predetermined water depth stable, and the spatial orientation of the docking port stable.

Additionally or alternatively, in at least another example, the underwater launch and recovery method comprises selectively and actively controlling said pivoting movement between said first arm end and said surface vehicle. For example, the connector arm is at least partially submerged to provide said predetermined water depth to said docking port via said connector arm, the position of the docking port with respect to the surface vehicle via the connector arm defining a pitch angle, a roll angle and a yaw angle. For example, the underwater launch and recovery method comprises providing control inputs regarding the spatial position and attitude of the docking port, and controllably varying at least one of said pitch angle, roll angle, and yaw angle, responsive to said control inputs. For example, the underwater launch and recovery method comprises sensing pivoting movement of the docking port about respective pitch, yaw and roll axes, and sensing accelerations of the docking port along said respective pitch, yaw and roll axes, to provide said control inputs. For example, said connecting arm comprises a single arm segment joining said first arm end to said second arm end, and wherein said single arm segments operates as a rigid body; alternatively, for example, said connecting arm comprises a first arm segment comprising said first arm end, and a second arm segment comprising said second arm end, said first arm segment being connected to said second arm segment via a free joint, and wherein each one of said first arm segment and said second arm segment operates as a rigid body.

Additionally or alternatively, the underwater launch and recovery method comprises selectively moving the connector arm between a stowed position and a deployed position, wherein in the stowed position the docking port is immovably engaged to the surface vehicle, and wherein in the deployed position the connector arm is at least partially submerged to:

provide said predetermined water depth to said docking port via said connector arm, and

to allow decoupling of at least said underwater heave movement of the docking port from surface heave movement of surface water vehicle at said predetermined water depth via said connector arm.

Additionally or alternatively, the underwater launch and recovery method comprises decoupling surface pitch, roll and yaw movements of surface water vehicle from the docking port at said predetermined water depth.

A feature of at least some examples of the presently disclosed subject matter is that launching and recovery of the underwater vehicle by the surface vehicle is possible at WMO Sea States greater than 1, including 3, 4, and 5, and even higher, depending on the ruggedness and/or design of the underwater vehicle and the docking port of the surface vehicle, and/or on the depth at which the docking operation is performed.

Another feature of at least some examples of the presently disclosed subject matter is that launching and recovery of the underwater vehicle by the surface vehicle can be carried out in an autonomous or remotely piloted manner, enabling the operators to be far away from the launching and recovery site; at the same time, this also allows the surface vehicle to ferry the underwater vehicle to a launch and recovery site, safely and at high speed. Such a feature may be useful where the operational site can be dangerous, for example a mine field. Another feature of at least some examples of the presently disclosed subject matter is that the surface vehicle can transfer the underwater vehicle from one desired location to another in a time and cost effective manner.

Another feature of at least some examples of the presently disclosed subject matter is that the underwater vehicle can be configured for mine clearing operations, including follow up damage assessment after neutralization of the mine, in a safe and efficient manner.

Another feature of at least some examples of the presently disclosed subject matter is that the underwater vehicle can operate in the desired manner while tethered to the surface vehicle close thereby, requiring a relatively short tether, minimizing risk of cable entanglement, and minimizing the forces applied by, and thus the effects of, underwater currents on the cable.

Another feature of at least some examples of the presently disclosed subject matter is that the surface vehicle can be maintained in a position close to the underwater vehicle, for example providing power thereto via a tether, and serving as a radio and/or satellite communication relay station or platform for the underwater vehicle.

Another feature of at least some examples of the presently disclosed subject matter is that the underwater vehicle can be brought into proximity with and locked with respect to the surface vehicle in a safe manner, even in non-calm sea surface conditions.

Another feature of at least some examples of the presently disclosed subject matter is that the underwater vehicle can be reeled into close proximity to the docking port via the tether, and relative vertical positions between the underwater vehicle and the docking port is maintained stable for a range of WMO Sea States, including WMO Sea States greater than 1.

Another feature of at least some examples of the presently disclosed subject matter is that the launch and recovery system can be used for a variety of applications, including for example one or more of the following: wherein the underwater vehicle is a towable sonar array; for the launch and recovery of ROV's and other underwater vehicles used for construction and/or maintenance of equipment in marine oil fields and marine gas fields, or used for underwater survey and/or underwater rescue and/or underwater archaeology and/or other underwater operations, even in high sea states. BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, examples will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 illustrates in bottom isometric view, a first example of the launch and recovery system in deployed mode.

Fig. 2 illustrates in side view the example of Fig. 1.

Fig. 3 illustrates in rear view the example of Fig. 1; Fig. 3(a) illustrates the example of Fig. 3 in retracted mode.

Fig. 4 illustrates in partial fragmented side view an alternative variation of the example of Fig. 1.

Fig. 5 illustrates in partial fragmented rear view the movable connector of the example of Fig. 3(a).

Fig. 6 illustrates in partial fragmented isometric view the portions of the flexible joint of the example of Fig. 4.

Fig. 7 schematically illustrates variation of particle excursions with depth and surface heave movements of the surface vehicle of the example of Fig. 1.

Fig. 8 schematically illustrates forces acting on the movable connector in operation of the example of Fig. 1.

Fig. 9(a) and Fig. 9(b) schematically illustrate decoupling of the surface movements of the surface vehicle with respect to the docking port for the example of Fig. 1.

Fig. 10 illustrates in side view an alternative variation of the example of Fig. 1. Fig. 11 illustrates in isometric rear view another alternative variation of the example of Fig. 1 in retracted mode.

Fig. 12 illustrates in isometric rear view the example of Fig. 11 in deployed mode.

Fig. 13 illustrates in isometric side view the example of Fig. 12 with the underwater vehicle disengaged from the docking port. Fig. 14 schematically illustrates in rear view the example of Fig. 11 in deployed mode.

Fig. 15 illustrates in side view, a second example of the launch and recovery system in deployed mode.

Fig. 16 illustrates in side view an alternative variation of the example of Fig. 15.

DETAILED DESCRIPTION

Referring to Figs. 1 to 3, a system for launch and/or recovery of underwater vehicles (also referred to interchangeably herein as a launch and recovery system) according to a first example of the presently disclosed subject matter, generally designated 100, comprises a surface vehicle 200, an underwater vehicle 300, and a docking system 400 including a movable connector 500 (also referred to interchangeably herein as a movable docking arm system 500).

While in this example, the system 100 is used for launch and/or recovery of one underwater vehicle, the skilled practitioner appreciates that in alternative variations of this example and in other examples, the system 100 can be modified to include a plurality of underwater vehicles 300, suitably disposed on correspondingly suitably sized surface vehicle 200, and each of the underwater vehicles 300 can be launched and/or recovered from the surface vehicle 200.

While in this example, the system 100 is used both for launch and recovery of an underwater vehicle, the skilled practitioner appreciates that the system 100 can be used only for launching the underwater vehicle 300, for example when the underwater vehicle 300 is expendable or wherever it is intended for the underwater vehicle 300 not to be rejoined with its surface vehicle 200 but rather to be picked up elsewhere, for example in a conventional manner in calm seas, or by another surface vehicle similar to surface vehicle 200. Similarly, the skilled practitioner also appreciates that the system 100 can be used only for recovery of the underwater vehicle 300, for example when the underwater vehicle 300 has been launched via a different surface vehicle (e.g. similar to surface vehicle 200) or in a conventional manner in calm seas, and for example the surface vehicle 200 is sent to pick up the underwater vehicle 300 at the end of its mission. The surface vehicle 200 (also referred to interchangeably herein as a water surface vehicle, or as a water surface vessel, or as a surface vessel) is configured for travelling over a water surface (such as the surface of the ocean, or the surface of the sea, or the surface of a lake, or the surface of a river, or the surface of a water reservoir or other artificial body of water, for example) and for floating on the water surface, at least during launching and/or recovery operations of launch and recovery system 100.

In this example, the surface vehicle 200 is self propelled, and includes any suitable marine propulsion system. Such a marine propulsion system can include, for example any suitable internal combustion engine, for example diesel propulsion systems and hydraulic systems for reducing electromagnetic signature, or electric propulsion system, or a hybrid propulsion system.

The surface vehicle 200 in this example is in the form of a catamaran, comprising a port hull 202 and a starboard hull 204, each being, for example, of multi-cell configuration.

The port hull 202 and the starboard hull 204 are connected and laterally spaced from one another via a deck in the form of a raised, partially open frame 210, having a frame underside 215.

In this example, the surface vehicle 200 is unmanned, and is operated remotely by an operator via a suitable radio or satellite link (not shown), or is operated autonomously, and can include a suitable control and navigation system, optionally including any suitable satellite based positioning system, for example GPS.

In alternative variations of this example and in other examples, the surface vehicle 200 can have other configurations. For example, the surface vehicle can be configured as a multi-hull or single-hull surface vessel or any other surface boat, or hydrofoil, or a hovercraft, or a submersible craft (that nevertheless operates on or near the surface of the water at least during launch and/or recovery operations of launch and recovery system 100), and/or, the surface vehicle 200 can be manned. Nevertheless, the catamaran configuration for the surface vehicle 200 can provide a number of features including one or more of the following: greater stability during launch and/or recovery of the underwater vehicle; enables the launch and/or recovery of underwater vehicle to occur near to the center of gravity of the surface vehicle in a simple design; allows for launch and/or recovery of underwater vehicle without the need for the surface vehicle to be submerged thereby simplifying the design and minimizing the cost of the surface vehicle as compared with for example other configurations.

The underwater vehicle 300 (also referred to interchangeably herein as a submersible vehicle, or as a submersible vessel, or as an underwater vessel) is configured for operating when submerged, and can take many different forms. In this example, the underwater vehicle 300 is self propelled, comprising a suitable underwater propulsion system and a suitable underwater maneuvering system (not shown), and is tethered to the surface vehicle 200 via a tether 250, for example in the form of a cable. In at least this example, the tether 250 is configured for providing power transmission and/or data communication between the surface vehicle 200 and the underwater vehicle 300, at least in operation of the underwater vehicle.

In this example, the underwater vehicle 300 is also configured for mine hunting, including one or more of surveillance, hunting, location, detection, identification and neutralization of underwater mines, and other underwater operations. Thus, the underwater vehicle 300 comprises one or more of the following: suitable sensors, for example imaging equipment (optical imaging and/or sonar imaging (for example synthetic aperture sonar SAS)), guidance equipment, and also mine neutralization equipment (for example explosive charges that are controllably detonated when secured in place, by the underwater vehicle 300, in proximity to a located mine); manipulators, for example in the form of articulated manipulator arms for performing mechanical tasks in a marine environment, including for example for cutting the anchoring cable of moored mines. In this example, the underwater vehicle 300 is unmanned, and is also remotely piloted, via an operator in a geographic location that is suitably spaced from the underwater vehicle 300. Sensor feeds from the underwater vehicle 300 are transmitted to the operator via the radio or satellite link provided by the surface vehicle 200, in communication with the underwater vehicle 300 via data/communication lines (not shown) parallel to or provided in the tether 250, and operator commands to the underwater vehicle 300 are received by the radio or satellite link and channeled to the underwater vehicle 300 via the data/communications lines.

However, in alternative variations of the above or other examples, the underwater vehicle 300 can be configured for performing different tasks - for example underwater archaeology, and/or underwater exploration, and/or Oceanic floor surveying, and/or hunting/location/detection/identification of sunken ships or objects, and/or study of ocean ecology, and/or detection of smuggling operations, and/or undersea search and rescue, and/or underwater works (for example hunting/location/detection/identification gas fields, oil field, minerals, etc. and/or mining), and/or guarding/maintenance/managing fish farms, and/or underwater cable inspection and maintenance, and/or underwater pipe inspection and maintenance, and so on.

Additionally or alternatively, in alternative variations of the above or other examples, the underwater vehicle can have different configurations, including for example one of the following: the underwater vehicle is self propelled and is configured for operating unmanned in an autonomous manner, with or without a tether; the underwater vehicle is self propelled and is remotely operated without a tether, for example via acoustic communication; the underwater vehicle is optionally not self propelled, and is configured for operating unmanned, and operates while being towed by the surface vehicle - for example the underwater vehicle is configured as a towed sonar array.

The docking system 400 is configured for enabling the underwater vehicle 300 to be selectively engaged and secured with respect to the surface vehicle 200, particularly during recovery mode of the launch and recovery system 100, and for enabling the underwater vehicle 300 and the surface vehicle 200 to be selectively disengaged with respect to one another, particularly during launching mode of the launch and recovery system 100. The docking system 400 comprises a docking port 410 selectively engageable and disengageable with respect to the underwater vehicle 300, for example via a docking interface 420. The docking interface 420 is mounted to or is otherwise comprised in the underwater vehicle 300. The docking port 410 is connected to the surface vehicle 200 via the selectively movable interconnector 500.

In this example, the docking port 410 comprises docking arms 415 that are movable from an open position OP to a closed position CP. In the open position, the docking interface 420 can be brought into proximity and engagement with the docking port 410, after which the docking arms 415 close to the closed position CP, locking the docking interface 420 with respect to the docking port 410, and thus locking the underwater vehicle 300 with respect to the surface vehicle 200. Referring also to Fig. 4, the docking arms 415 optionally comprise fenders 418 for absorbing or damping impact loads that be applied between the docking interface 420 and the docking port 410 during recovery and engagement operations of the docking system 400. In alternative variations of this example, the docking port can comprise a cage or hangar for accommodating therein the underwater vehicle 300, and the docking interface can comprise, for example, any part of the underwater vehicle 300 that can engage with the inside of the cage or hangar. For example the underwater vehicle 300 comprises skis for enabling the underwater vehicle 300 to rest on a surface, and such skis can constitute or form part of the docking interface. In addition, clamps can be provided to secure the underwater vehicle 300 to the inside of the hangar or cage.

A docking head 450 is provided proximal to docking port 410, and accommodates various equipment and services, for example floats and an instrument box including for example control mechanism for the docking port, data communication equipment, ballast tanks, gauges including at least depth gauges, magazines for replenishing expendable cargo of the underwater vehicle 300, and power for the underwater vehicle 300. Such cargo can include, for example, suitable explosives that can be used for detonating undersea mines. Thus, the underwater vehicle 300 can optionally be resupplied when docked, and/or its batteries recharged, and/or data (including new or updated operating instructions) can be uploaded or downloaded between the surface vehicle 200 and the underwater vehicle 300.

Optionally, the cable or tether 250 can be configured for powering the underwater vehicle 300 while docked or while undocked, and/or for enabling the underwater vehicle 300 to have its batteries recharged, and/or for enabling data (including new or updated operating instructions) to be uploaded or downloaded between the surface vehicle 200 and the underwater vehicle 300, either continuously or periodically.

Optionally, and particularly in alternative variations of the above example and in other examples, the launch and recovery system comprises an acoustic pinger mounted to the docking port 410 or docking head 450. Additionally or alternatively, a set of approach and docking lights can be provided in the underwater vehicle 300 and an optical sensor or imaging camera in the docking head 450 or docking port 410 to facilitate homing and navigation of the underwater vehicle 300 and capture via the docking system 400, particularly where there is no tether between the underwater vehicle and the surface vehicle 200; additionally or alternatively, docking lights can be provided in docking head 450 or docking port 410, and the an optical sensor or imaging camera in the underwater vehicle 300. Additionally or alternatively, an acoustic homing system (for example comprising an acoustic pinger in one of the underwater vehicle 300 or the docking system 400, and an acoustic receiver in the other one of the underwater vehicle 300 or the docking system 400) can also be provided to facilitate homing and navigation of the underwater vehicle 300 and capture via the docking system 400, particularly where there is no tether between the underwater vehicle and the surface vehicle 200.

Referring also to Fig. 7, the movable interconnector 500 is configured for providing a predetermined submerged depth H to the docking port 410 while the surface vehicle 200 is on the water surface, to thereby enable selective docking and undocking between the surface vehicle 200 and the underwater vehicle 300 at the predetermined depth H. As will become clearer herein, this predetermined depth H is a minimum depth at which heave q of the underwater vehicle 300 (as a result of water surface conditions, such as wave amplitude) is within an acceptable range Rl. The movable interconnector 500 is also configured for raising the docking port 410 with the underwater vehicle 300 engaged to the movable interconnector 500 while the surface vehicle 200 is on the water surface, to thereby enable the underwater vehicle 300 to be locked in position with the surface vehicle 200, for example with the underwater vehicle 300 raised above the water surface.

The movable interconnector 500 is also configured for decoupling at least heave movement q of the underwater vehicle 300 at the predetermined depth H from surface heave movement Q of surface vehicle 200 while the underwater vehicle 300 is connected to or is in close proximity to the surface vehicle 200, particularly during launch and/or recovery operations. In other words, at least when providing said depth H to the docking system 400, the movable interconnector 500 operates to ensure that most or all of surface heave movements Q experienced by the surface vehicle 200 are not transmitted to the underwater vehicle 300 (again, while the underwater vehicle 300 is docking or undocking with respect to the surface vehicle 200, particularly during launch and/or recovery operations), and thus the underwater vehicle 300 is thereby not compelled to mimic or follow these surface heave moments; rather, the underwater vehicle 300 only experiences the heave q appropriate for depth H at the prevalent sea state.

It is to be noted that at least in this example, the movable interconnector 500 is also configured for decoupling roll, pitch and yaw movements, in addition to heave movement q, of the underwater vehicle 300 at the predetermined depth H from surface roll, pitch and yaw movements as well as surface heave movement Q of surface vehicle 200 while the underwater vehicle 300 is connected to or is in close proximity to the surface vehicle 200, particularly during launch and/or recovery operations. In other words, at least when providing said depth H to the docking system 400, the movable interconnector 500 operates to ensure that most or all of surface roll, pitch and yaw movements as well as surface heave movements Q experienced by the surface vehicle 200 are not transmitted to the underwater vehicle 300 (again, while the underwater vehicle 300 is docking or undocking with respect to the surface vehicle 200, particularly during launch and/or recovery operations), and thus the underwater vehicle 300 is thereby not compelled to mimic or follow these surface roll, pitch, yaw or heave moments; rather, the underwater vehicle 300 only experiences the roll, pitch and yaw movements and the heave q appropriate for depth H at the prevalent sea state.

Such surface heave movements Q are often caused by surface waves and are correlated to the amplitudes of the surface waves. The greater the sea state, the larger these heave movements Q can be. For example, Table I below lists average wave amplitudes (which correlate to surface heave movements Q) corresponding to several sea states, as classified by the World Meteorological Organization (WMO).

TABLE I

World Meteorological Organization (WMO) Sea State Codes and Corresponding

Average Wave Amplitudes

In this example, the movable connector 500 is also configured for decoupling the docking port 410 at the predetermined depth H from one, two or all of roll, pitch and yaw surface movements of surface vehicle 200, again while the underwater vehicle 300 is in proximity with the surface vehicle 200, particularly during launch and/or recovery operations.

In this example, and referring in particular to Fig. 4, the movable connector 500 comprises launch and recovery arm 520 (also referred to interchangeably herein as an arm, or a connector arm, or a boom, or a launch and recovery boom), having a free distal arm end 525 onto which the docking port 410 is mounted via docking head 450, and a proximal arm end 522 movably connected at to the frame 210 via a joint arrangement in the form of flexible joint 550.

In particular, the flexible joint 550 is configured to allow the arm 520 to pivot with respect to the surface vehicle 200 in at least two degrees of freedom, i.e., in pitch and roll, and furthermore the flexible joint 550 is movably connected to the surface vehicle 200 to allow the arm 520 to pivot in yaw via the flexible joint 550. However, in at least some alternative variations of this example the flexible joint 550 is configured to allow the arm 520 to pivot with respect to the surface vehicle 200 in one degree of freedom, i.e., in pitch only (and thus the respective flexible joint only needs to allow pivoting in pitch), or, the flexible joint 550 is configured to allow the arm 520 to pivot with respect to the surface vehicle 200 in only in two degrees of freedom, i.e., in pitch and in roll only (and thus the respective flexible joint is fixedly connected to the surface vehicle 200 and does not allow the arm 520 to pivot in yaw via the respective flexible joint).

In this example, flexible joint 550 comprises an articulated joint construction, for example a universal joint or a Cardan joint, having a plurality (at least two) joint elements 560. In Fig. 4, the flexible joint 550 is shown as having five joint elements 560, but in alternative variations of this example a different number of joint elements can be provided. In any case, each pair of adjacent joint elements 560 are pivotably connected to one another with respect to a pivot axis P, and adjacent pivot axes P are orthogonal to one another and orthogonal to the longitudinal axis of the respective joint elements 560. The most distal joint element 560D is pivotably mounted to the proximal end 522 of the arm 520. The most proximal joint element 560P is pivotably mounted to a rotary stage 566 on the underside 215 by another pivot axis P. The rotary stage 566 is itself pivotably mounted to the underside 215 about the yaw axis YA of the surface vehicle 200, allowing the arm 520-flexible joint 550 assembly to yaw with respect to the surface vehicle 200 independently of the pitch angle Θ and independently of the roll angle φ of the arm 520 (see Fig. 2).

In alternative variations of the above example and in other examples, the flexible joint 550 can have any other suitable form, for example, a bellows arrangement or asemi-stiff tubing, in either case comprising a suitable guide for the tether 250 to pass therethrough.

In this example, the arm 520 is formed as a single element, in the sense that the arm 520 pivots with respect to the surface vehicle 200 as a rigid body. Furthermore, the arm 520 is tubular, elongate and rectilinear in this example.

As can be seen in Fig. 2, the arm 520 can be pivoted about a pitch axis PA of the surface vehicle 200 from a retracted or stowed position RP generally parallel to the underside 215 to a deployed position DP in which the arm 520 is at a pitch angle Θ with respect to the longitudinal axis LA of the surface vehicle 200. In this example, the flexible joint 550 provides a full range R2 for pitch angle Θ from at least 0° (parallel to the longitudinal axis LA of the surface vehicle 200, and the arm facing aft) in a clockwise direction as viewed in Fig. 2 to at least -180° (again parallel to the longitudinal axis LA of the surface vehicle 200, and the arm facing forward). Optionally, the pitch angle Θ can reach a positive value of about +10° in the stowed position, i.e., counterclockwise from the 0° position. This can be useful in further raising the docking system 400 including the movable connector 500, above the water line.

In the deployed mode this range for pitch angle Θ is nominally from about -5° to about -175°, and in practice, in the deployed mode the pitch angle Θ is between about -5° to about -90°, typically between about -30° to about -60°, for example any one of -35° or - 40° or -45° or -50° or -55°.

Referring again to Fig. 4 in particular, a main cable 529 is connected at one end 528 thereof to the docking port 410 that is at the free distal end 525 of the arm 520, and this main cable 529 is connected at the other end 527 thereof to a winch or windlass 528 mounted to an aft end of the frame 210, the windlass 528 being configured for selectively winching the arm 250 from the deployed position DP to the retracted position RP.

The windlass 528 is optionally also configured for selectively allowing the arm 520 to deploy from the retracted position RP to any desired maximum deployed position DP, and for selectively changing the maximum deployed position DP to a different maximum deployed position DP. Thus, the length of main cable 529 that is reeled out from windlass 528 (with respect to the retracted position RP) determines the maximum pitch angle Θ available for the arm 520 (corresponding to the maximum deployed position DP), and this enables the arm to adopt a smaller, desired pitch angle Θ when the main cable 529 is thus reeled out, thereby enabling the arm 520 to naturally adopt the desired pitch angle Θ (smaller than the maximum pitch angle Θ) during launch or recovery operations of the system 100, without interference from the main cable 529.

A releasable locking mechanism 270 is also provided for locking the docking system 400 in the retracted portion RP, and comprises a hook element 272 at the end 528 of cable 529, and a catch or bar element 274 near the windlass 528 for selectively engaging/disengaging with the hook element 272. Additional clamping elements can optionally be provided to further secure the docking system 400 and the underwater vehicle 300 to the surface vehicle 200.

Referring in particular to Figs. 1, 3 and 3(b), the underside 215 further optionally comprises wedge-shaped guides 280 for guiding the arm 520 into the retracted position RP. As can be seen in Fig. 5, the guides 280 can optionally comprise fenders 282 with shock absorbing elements 281 for absorbing or damping impact loads that be applied between the arm 520 and the surface vehicle 200 during deployment or retraction operations of the arm 520.

In addition, the arm 520 can optionally also be pivoted about a yaw axis YA of the surface vehicle 200 while in the deployed position DP in which the arm 520 is at a yaw angle β with respect to the longitudinal axis LA of the surface vehicle 200 (see Fig. 1). Similarly, the arm 520 can optionally also be pivoted about a roll axis (typically the longitudinal axis LA or parallel thereto) of the surface vehicle 200 while in the deployed position DP in which the arm 520 is at a roll angle φ with respect to the yaw axis YA of the surface vehicle 200 (see Fig.3).

In this example, the flexible joint 550 provides a range for yaw angle β from about +45° to about -45°. It is to be noted that typically, while the surface vehicle 200 is in forward motion and the arm 520 is the deployed position DP, the yaw angle β is negligible, i.e. 0° or close thereto. The degree of freedom in yaw for the arm 520 is typically useful in situations wherein the surface vehicle 200 is stationary, and it may be useful for the arm to pivot in an unrestricted manner in pitch, roll and yaw. On the other hand, the surface vehicle 200 can be fitted with maneuvering thrusters to maintain position as well as orientation, in which case the flexible joint 550 can be fixedly mounted to the surface vehicle 200, i.e., without allowing pivoting in yaw.

As can be seen in Fig. 3, two auxiliary cables 567 can optionally be provided to control sideways movement of the free distal end 525 of the arm 520, and thus to control or limit the yaw angle β and the roll angle φ of the arm 520 at any desired pitch angle Θ, in particular during launch or recovery operations where the arm is rising towards, or falling away from the locked position with respect to the surface vehicle 200, when the arm 520 is out of the water. Each auxiliary cable 567 is connected to one or the other lateral side of the free distal end 525 and to a respective winch and windlass system 569 symmetrically mounted to an aft end of the frame 210 with respect to the retracted position RP of the arm 520. The two winch and windlass systems 529 are interconnected and the length of auxiliary cable 528 that is reeled out from each windlass 529 limit sideways movement of the arm particular during launch and recovery operations by limiting the yaw angle β and the roll angle φ, minimizing risk of collision between the arm and the surface vehicle 200.

Referring again to Fig. 4, the arm 520 and the flexible joint 550 are hollow, comprising a lumen, allowing the tether 250 to pass from a reel or drum 255, mounted on the surface vehicle 200, via cable guide 258 and rollers 253 through the flexible joint 550 and the arm 520 to the docking port 410 and thence to the underwater vehicle 300. As best seen in Fig. 6, the individual joint elements 560 can each be provided with a pair of spaced rollers 563 to facilitate reeling in and reeling out of the tether 250 with respect to the drum 255 (driven by a suitable powered winch, not shown), as the underwater vehicle is brought into proximity with and distanced from, respectively, the surface vehicle 200. The rollers 563 also minimize friction between the joint elements 560 and the tether 250 (or at least the part thereof that is inside the flexible joint 550), protect the tether 250, and allow efficient and smooth decoupling of heave movement of the underwater vehicle 300 from surface heave movement of surface vehicle 200 via movable interconnector 500. The rollers 563 also allow efficient and smooth decoupling of pitch, roll and yaw movement of the underwater vehicle 300 from surface movements of surface vehicle 200 via movable interconnector 500. The drum 255 can be mounted on the upper side 216 or on the lower side 215 of the frame 210, for example on the rotary stage 566 to pivot in yaw together with the arm 520, thereby minimizing or eliminating risk of twisting of the tether 250 during yawing movements.

Referring to Figs. 7 and 8, the launch and recovery system 100 can be used according to the following method for launch and/or recovery of underwater vehicles 300, even at seas states greater than WMO sea states 0 and 1 that correspond to calm waters.

According to at least a first example of this method, the underwater vehicle 300 is in close proximity to the docking port 410 (both, when launching or recovering the underwater vehicle 300), and relative movement between the two, caused by movement of the surrounding water environment, is minimized.

For the purpose of minimizing this relative movement, docking and undocking of the underwater vehicle 300 with respect to the surface vehicle 200 is carried out at a predetermined depth H for the underwater vehicle 300, in which heave of the underwater vehicle 300 as a direct result of water surface conditions is within a range of, for example, about 0m to 0.1m, but can be greater according to the ruggedness of the underwater vehicle 300 and of the docking port 410. In particular, docking and undocking of the underwater vehicle 300 with respect to the surface vehicle 200 is carried out at a predetermined depth H for the underwater vehicle 300, in which relative heave displacements between the underwater vehicle 300 and the docking port 410, as a direct result of water surface conditions, is within range R. For example, R can be the range 0m to 0.1m, and the relative speed between the underwater vehicle 300 and the docking port 410 can be a few cm/sec, allowing soft docking without damaging the underwater vehicle 300 or the arm 520 or the docking port 410.

It is well known in the art that (water) particle motion amplitude reduces with depth away from the water surface. Thus, for example, given a WMO Sea State of 3, with a particular surface wave having an amplitude of 1.10m and wavelength 14m, surface (water) particles will move vertically through an amplitude of 1.10m; however, at a sea bed depth of 10m or greater, (water) particles at a depth of about 7m will only exhibit heave with an amplitude of about 0.05m. According to some theoretical studies (for example the Airy Wave Theory or Linear Wave Theory), particle movement ζ (also referred to interchangeably herein as particle excursion or particle motion amplitude) of water particles in deep water (i.e., the water depth h to the sea bed being greater than half the surface wave lengths) reduces exponentially with depth. The term "sea bed" is used herein interchangeably with "sea bottom", and also refers to the bottom of other bodies of water, for examplerivers, lakes, reservoirs, etc., mutatis mutandis.

Thus, particle movement ζ at surface depth z (i.e., at an average depth z from the water surface) is related to surface wave amplitude Ao, surface wave length λ, and depth z, by expression (1) below (for sea bottom water depths h greater than half of the wave length λ) :

ζ = Α 0 ζ(2π/λ) (1)

For sea bottom water depths h (i.e., depth of water from the surface to the sea bed less than 50% but greater than 5% of surface wave length λ, the vertical particle motion amplitude ζν, and the horizontal particle motion amplitude ζπ can be derived from the following expressions (2) and (3), respectively, provided by the aforesaid the Airy Wave Theory or Linear Wave Theory:

ζ ν = + h)))/(sinh((2ji/ )*h)) (2) ζ Η = A 0 *(cosh(2ji/ (z + h)))/(sinh((2ji/ )*h)) (3)

Table II below provides examples vertical particle motion amplitude ζν, and the horizontal particle motion amplitude ζπ vertical amplitude as well as horizontal amplitude) for a range of WMO sea states, wave amplitudes and wave lengths, obtained with expressions (1), (2) or (3) above.

TABLE II

Particle Excursion at a Variety of WMO Sea States and Conditions

Thus, for example, the value for depth z corresponding to the predetermined depth H for undocking and docking of the underwater vehicle 300 with respect to the surface vehicle 200, when respectively launching or recovering the underwater vehicle 300, can be about 7m in WMO sea state 3, with average sea wave lengths of 14m to 16m. In sea depths h of 10m or greater, the respective particle motion amplitude ζ will be about 0.05m to 0.08m; even in sea depths h of about 6m or 7m, the respective vertical particle motion amplitude ζν will be between about 0.13m and 0.15m.

It is also to be noted that the relative motion between the underwater vehicle 300 and the arm 520, at a mutual spacing between the two of about lm, is a function of the wavelength λ of the sea waves, approximately (2/λ) of the particle excursion ζ, i.e., only a few centimeters, even at a WMO Sea State 5.

The movable connector 500 can be deployed to a desired deployed position DP from the retracted position RP by unlocking the locking mechanism 270, and reeling out the cable 529 from the drum 528, to allow the arm to freely pivot downwardly and adopt any pitch angle Θ within a desired range that will enable the docking port 410 to be submerged to the desired predetermined depth H. In operation of the launch and recovery system 100, the heave motion Q of the surface vehicle 200 is decoupled from the docking port 410, and thus it follows that relative movement (in heave due to the surface wave motion) between the docking port 410 and the underwater vehicle 300 during the aforesaid undocking and docking of the underwater vehicle 300 with respect to the surface vehicle 200, when respectively launching or recovering the underwater vehicle 300, is actually very small. In at least some cases, such relative movement is significantly smaller than the heave q of the underwater vehicle 300. In addition, in operation of the launch and recovery system 100, one or more of, and typically all of, roll pitch and yaw motion of the surface vehicle 200 is decoupled from the docking port 410, and thus it follows that relative movement (in roll pitch and/or yaw due to the surface wave motion) between the docking port 410 and the underwater vehicle 300 during the aforesaid undocking and docking of the underwater vehicle 300 with respect to the surface vehicle 200, when respectively launching or recovering the underwater vehicle 300, is zero or very small.

In operation of the underwater launch and recovery system 100 for launching or recovering the underwater vehicle 300, the surface vehicle 200 is caused to move with a forward velocity while the connector arm 520 is at least partially submerged to provide a predetermined water depth H to the docking port 410 via said connector arm 410, the position of the docking port with respect to the surface vehicle 200 via the connector arm defining a pitch angle Θ. For example, at this forward velocity, a tension and a drag are induced in the connector arm; for example, the tension balances the weight and drag of the arm, thereby maintaining the depth and spatial orientation of the docking port stable.

According to this first example of the method, the heave motion Q of the surface vehicle 200 is decoupled from the docking port 410 as follows. Referring in particular to Fig. 8, with the movable connector 500 in the deployed position such that the docking port 410 is at said predetermined depth H, the surface vehicle 200 is provided with forward motion at a predetermined velocity V, which is maintained at a controlled velocity to ensure that the depth H is maintained constant. At velocity V, a number of forces are induced at the free end 525 (including the docking port 410 and docking head 450), including: the weight mg of the free end 525 (including the docking port 410 and docking head 450), acting vertically downwards, drag force D induced by the docking head 450 and docking port 410 acting in a generally horizontal direction away from the direction of motion of the surface vehicle 200, and tension T in the arm 520, in a direction along the longitudinal axis thereof towards the surface vehicle 200 and thus at the respective pitch angle Θ with respect to the horizontal . Tension T thus has a horizontal component that balances the drag D, and a vertical component (lift force that balances the weight mg. The tension T and drag D intersect at a point f that acts as a fulcrum. Thus, as illustrated in Figs. 9(a) and 9(b), the balance of forces between the tension T, drag D and weight mg maintain the pitch angle Θ Η of the arm 520 with respect to the horizontal constant even where the surface vehicle 200 is experiencing severe heave H (for example due to severe WMO Sea State conditions), in which surface movements of the surface vehicle 200 (in particular heave movements) are decoupled from the arm 520 via the flexible joint 550. Thus, and as illustrated in Figs. 9(a) and 9(b), the pitch angle Θ Η of the arm 520 with respect to the horizontal constant, while the pitch angle Θ between the arm 520 and the longitudinal axis LA may be changing, and while the pitch angle θ' between the longitudinal axis LA and the horizontal may be changing .

The free end 525, in particular the docking port 410 and/or the docking head 450, is configured for providing a desired level of drag D when the surface vehicle 200 is travelling at a desired forward velocity V for launch and recovery operations.

It is to be noted that according to this first example of the method, the roll, pitch and yaw motions of the surface vehicle 200 are decoupled from the docking port 410 via the flexible joint 550 including the rotary stage 566.

The drag D increases with velocity V (and in fact drag D is proportional to V 2 ), and the tension T increases correspondingly.

It is to be noted that hydrostatic forces can optionally be used to adjust the buoyancy of the docking system 400 including the movable connector 500, in particular one or more of the arm 520, the docking head 450 and the docking port 410, in order to provide a desired net weight mg. Furthermore, hydrodynamic forces can also be present, and act in all directions. Such hydrodynamic forces are a function of the orientation of the arm 520 (and thus of pitch angle Θ and possible also of yaw angle β), of the hydrodynamic design of the docking head 450 and docking port 410, of the forward speed V. It is also to be noted that such hydrodynamic forces can optionally be used to further control or supplement the lift force L by providing the movable connector 500 with suitable fins, which can be stationary (for example, fixed at a preset angle), or movable. In the case of movable fins, these can be controlled, for example, using suitable active control (e.g. a computer controller connected to suitable sensors) or via mechanically simple hydrostatic control systems to balance, thereby introducing a the lift force L and adjusting the pitch angle Θ. It is also to be noted that such hydrodynamic forces can optionally be reduced or practically eliminated by providing a corresponding hydrodynamic design for the docking head 450 and docking port 410.

In any case, as speed V of the surface vehicle is increased, the depth z of the docking port 410 is decreased, and vice versa. Thus, the speed V of the surface vehicle 200 can be used for controlling the pitch angle Θ and the depth of the docking port 410, and thus a stable depth z can be provided corresponding to the predetermined depth H.

Optionally, the predetermined depth H of the docking port 410 can be further controlled via one or more controllable small propulsion maneuvering units provided at fulcrum or close thereto.

Once this stable depth has been achieved, heave movements Q of the surface vehicle 200, being decoupled from the arm 520 via the flexible joint 550, do not affect at all, or to any significant degree, the vertical position of the docking port 410, providing zero or little relative movement (at least vertically) between the underwater vehicle 300 and the docking port 410.

The length of arm 520 and the drag D, together with the flexible structure of the flexible joint 525, thus act to decouple the surface heave Q from the docking port 410, which is close to the fulcrum point f. it is to be noted that the movable connector 500 also decouples yaw, roll or pitch of the surface vehicle 200 from the docking port 410.

This decoupling in turn enables the underwater vehicle 300 to be reeled via the tether 250 into an engagement position in which the docking interface 420 engages and locks with the docking port 410.

Thus, the stable predetermined depth H is achieved by the moveable connector 500 in an indirect manner, by controlling the surface vehicle speed V.

Once the underwater vehicle 300 is secured to the movable connector 500, a number of options are open. For example, the underwater vehicle 300 can be resupplied via the docking head 450, and/or the underwater vehicle can be stowed for the next operation. For the latter purpose, the arm 520 is raised by the winch 528 to the retracted position, and locked therein via the locking mechanism 270. In this position, the underwater vehicle is fully above the water surface, and the surface vehicle 200 can then transport the underwater vehicle to any desired location.

Other variations of the above example of the movable connector are possible. For example, and referring to Fig. 10, such a movable connector can comprise, in addition to the flexible joint 550, an arm 520 comprising two arm segments 520A, 520B, serially connected via a free joint 520C, which can include a weight ballast. The first arm segment 520A is connected to the flexible joint 550, while the second arm segment 520B includes the end 525 and thus carries the docking port 410 including the docking head 450. For example, the second arm segment 520B can be configured and operated to maintain the orientation of the docking port 510 constant (for example horizontal), irrespective of the movement of the first arm segment 520B, possible via the free joint 520C, and thus the first arm segment 520A can be operated with a range of pitch angles Θ. For example, the second arm segment 520B can comprise fins or propulsion units for this purpose, while the first arm segment can pivot to compensate further for heave movements of the surface vehicle 200. Alternatively, the first arm segment 520A comprises fins 520D for maintaining a fixed pitch angle for the first arm segment, 520A, and the second arm segment 520B pivots to a desired pitch angle Θ according to the balance of forces between the tension T, drag D and weight mg of the arm 520 constant even where the surface vehicle 200 is experiencing severe heave H (for example due to severe WMO Sea State conditions, in which surface heave movements of the surface vehicle 200 (and also pitch/roll/yaw movements) are decoupled from the arm 520 via the flexible joint 550 and free joint 520C.

In operation of the system 100 for launching an underwater vehicle 300, the surface vehicle 200 propels the system 100 to a predetermined deployment zone, while the movable connector 500 is in the retracted position, above the water line. In this configuration, the system 100 minimizes drag and can travel to its destination efficiently and fast. Once the system 100 arrives at the deployment zone, the movable connector 500 is lowered into the water to the deployed position, at least partially submerged to provide via the connector arm 520 the predetermined water depth H to the underwater vehicle 300, which is engaged to the docking port 410. The surface vehicle 200 then moves with a forward velocity V, such that a tension and a drag are induced in the connector arm 520, in particular such that the tension balances the weight and drag of the arm, thereby maintaining the depth and spatial orientation of the docking port stable. At this point, the movements of the surface vehicle 200 are essentially decoupled from the docking port 410, and thus the underwater vehicle 300 can undock from the docking port 410 and carry out its mission.

Operation of the system 100 for recovering an underwater vehicle 300 is essentially the reverse of the launching operation. In examples where the surface vehicle 200 is connected to the underwater vehicle 300 via the tether 250, the surface vehicle first reels in the tether 250 until the two vehicles are in close proximity, for example a few meters, depending on the wave height. The movable connector 500 is in the deployed position, with the docking port 410 submerged. . The surface vehicle 200 then moves with a forward velocity V, such that a tension and a drag are induced in the connector arm 520, in particular such that the tension balances the weight and drag of the arm, thereby maintaining the depth at the predetermined water depth H for the docking port 410, by providing a constant pitch angle Θ Η with respect to the horizontal, and thereby maintaining spatial orientation of the docking port stable. At this point, the movements of the surface vehicle 200 are essentially decoupled from the docking port 410, and thus the underwater vehicle 300 can be further reeled in via the tether 250 until it engages and docks with the docking port 410. Once the underwater vehicle 300 is secured to the movable connector 500, this is raised to the retracted position, above the water line. Thereafter, the system 100 can be deployed to a different location or operational site.

It is to be noted that other alternative variations of the above example of the docking system 400 or parts thereof are also possible. For example, in some such alternative variations, the winch and windlass system 569 illustrated in Fig. 3 can be omitted, and the auxiliary cables 567 are secured directly to the frame 210, as illustrated in Figs. 11 to 13 for example. Furthermore, the lower ends of the auxiliary cables 567 are not secured to the docking system 400, but rather to opposite sides of a ring member 576, through which the main cable 529 is threaded. As can be seen in Figs. 12 and 13, for example, the lengths of the auxiliary cables 567 is relatively small, so that when the main cable 529 is extended to allow the arm 520 to adopt a large pitch angle θ , the ring member 576 is suspended high above the docking port 410. On the other hand, when the movable connector 500 is in the retracted configuration illustrated in Fig. 11, the ring member 567 is displaced upwards by the docking port 410. Referring also to Fig. 14, each of the auxiliary cables 567 is attached at one end 567a thereof to a respective one of hulls 202 and 204 at a respective anchor point 289. The other end 567b of each auxiliary cable 567 is attached to the ring member 576. Theoretically, the ends 567b (if not attached to the ring member 576) can be positioned anywhere within a respective circle CI of radius Rl, wherein radius Rl is the length of the respective auxiliary cable 567, this being less than the lateral spacing S between the two anchor points 289. However, since the ends 567b are indeed connected to the ring member 576, the ends 567b are constrained to move only within the area W of overlap between the two circles CI, which thus avoids the hulls 202, 204. This arrangement reduces risk of cable entanglement on the one hand (for example as compared with the example of Fig. 1), while minimizing risk of collision between the docking port 410 (together with the underwater vehicle 300) and the surface vehicle 200 (in particular the hulls 202, 204) while the docking system 400 is being raised to the retracted configuration.

Referring to Fig. 15, a second example of the launch and recovery system, generally designated 100', comprises the elements and features of the first example of the launch and recovery system 100 or alternative variations thereof, as disclosed herein but with some differences, mutatis mutandis. Thus, the launch and recovery system 100' comprises surface vehicle 200, and underwater vehicle 300, as disclosed for the first example or alternative variations thereof, mutatis mutandis. The launch and recovery system 100' also comprises docking system 400' which includes a movable connector 500', similar to the docking system 400 and movable connector 500 of the first example, but with some differences mutatis mutandis, as will become clear herein.

In particular, the movable connector 500' of the second example is also configured for providing a predetermined submerged depth H to the docking system 400 while the surface vehicle 200 is on the water surface, to thereby enable selective docking and undocking between the surface vehicle 200 and the underwater vehicle 300 at the predetermined depth H. As for the first example, this predetermined depth H is a minimum depth at which heave q of the underwater vehicle 300 (as a result of water surface conditions, such as wave amplitude) is within an acceptable range Rl. The movable interconnector 500' is also configured for actively raising the docking system 400 with the underwater vehicle 300 engaged to the movable interconnector 500' while the surface vehicle 200 is on the water surface, to thereby enable the underwater vehicle 300 to be locked in position with the surface vehicle 200, for example with the underwater vehicle 300 raised above the water surface.

The movable interconnector 500' is also configured for actively decoupling at least heave movement q of the underwater vehicle 300 at the predetermined depth H from surface heave movement Q of surface vehicle 200 while the underwater vehicle 300 is connected to or is in close proximity to the surface vehicle 200, particularly during launch and/or recovery operations. In other words, at least when providing said depth H to the respective docking port 410 of docking system 400', the movable interconnector 500' operates to ensure that most or all of surface heave movements Q experienced by the surface vehicle 200 are not transmitted to the underwater vehicle 300 (again, while the underwater vehicle 300 is docking or undocking with respect to the surface vehicle 200, particularly during launch and/or recovery operations), and thus the underwater vehicle 300 is thereby not compelled to mimic or follow these surface heave moments; rather, the underwater vehicle 300 only experiences the heave q appropriate for depth H at the prevalent sea state.

The docking port 410 of docking system 400' is as disclosed for the first example or alternative variations thereof, mutatis mutandis.

It is to be noted that at least in this example, the movable interconnector 500' is also configured for decoupling roll, pitch and yaw movements, in addition to heave movement q, of the underwater vehicle 300 at the predetermined depth H from surface roll, pitch and yaw movements as well as surface heave movement Q of surface vehicle 200 while the underwater vehicle 300 is connected to or is in close proximity to the surface vehicle 200, particularly during launch and/or recovery operations. In other words, at least when providing said depth H to the docking port 410, the movable interconnector 500' operates to ensure that most or all of surface roll, pitch and yaw movements as well as surface heave movements Q experienced by the surface vehicle 200 are not transmitted to the underwater vehicle 300 (again, while the underwater vehicle 300 is docking or undocking with respect to the surface vehicle 200, particularly during launch and/or recovery operations), and thus the underwater vehicle 300 is thereby not compelled to mimic or follow these surface roll, pitch, yaw or heave moments; rather, the underwater vehicle 300 only experiences the roll, pitch and yaw movements and the heave q appropriate for depth H at the prevalent WMO Sea State.

In this example, the movable interconnector 500' is in the form of a robotic connector arm 520', and a joint arrangement in the form of an active flexible joint arrangement 540' configured for selectively and actively controlling the movement between the respective free arm end 525 and the surface vehicle 200.

The active flexible joint arrangement 540' comprises a base 501' attached to the surface vehicle 200, for example the underside 215 thereof.

The active flexible joint arrangement 540' further comprises a first arm platform 502' is pivotably mounted to the base 501' via a first motorized joint 503' to allow selective active relative pivoting movements between the first arm platform 502' and the base 501' about a yaw axis YA.

The active flexible joint arrangement 540' further comprises a second arm platform 504' is pivotably mounted to the first arm platform 502' via a second motorized joint 505' to allow selective active relative pivoting movements between the second arm platform 504' and the first arm platform 502' about a roll axis RA.

The active flexible joint arrangement 540' further comprises a third motorized joint 507'. The arm 520' is pivotably mounted to the second arm platform 504' via the third motorized joint 507' to allow selective active relative pivoting movements between the arm 520' and the second arm platform 504' about a pitch axis PA. The arm 520' is similar to the arm 520 of the first example, mutatis mutandis, and includes arm end 525, including the docking port 410 and docking head 450, mutatis mutandis.

An inertial control unit 530' is provided, for example at end 525. The inertial control unit 530' is configured for actively controlling the spatial position (in particular depth) and spatial attitude of the docking port 410 with respect to the Earth, and in particular for maintaining this spatial position and attitude of the docking port 410 stable during docking and undocking of the underwater vehicle 300 with respect to the surface vehicle 200, in particular with respect to the docking port 410, even at WMO Sea States greater than 1, for example at WMO Sea States of 2, 3, 4, 5 or higher than 5. In this example, the inertial control unit 530' comprises inertial sensors and water depth sensors. The inertial sensors are configured for sensing the angular disposition of the docking head 450 or docking port 410 with respect to the pitch axis PA, the roll axis RA and the yaw axis YA, as well as accelerations along each of these three axes, in particular along the heave direction. A controller (for example a computer system or an electronic controller) in the inertial system 530' or elsewhere in the system 100 provides control commands, based on sensor information provided by the inertial sensors, to the first motorized joint 503', and/or to the second motorized joint 505', and/or to the third motorized joint 507', to thereby control respective pivoting angles of the arm 520' in pitch, roll (via second arm platform 504') and yaw (via first arm platform 502') to thereby maintain stable the spatial attitude of the docking port 410 with respect to the Earth. The water depth sensors can comprise a depth gauge, for example, and sensor information regarding depth from the water depth sensors can be provided to the controller, which provides control commands, based on this sensor information, to the first motorized joint 503' and/or the second motorized joint 505', and/or the third motorized joint 507' to thereby control respective pivoting angles of the arm 520' in pitch, roll (via second arm platform 504') and yaw (via first arm platform 502') to thereby maintain the spatial depth of the docking port 410 with respect to the Earth stable.

For example, the inertial system 530' can comprise an inertial navigation system (INS) plus a depth gauge, operatively connected to the controller.

Thus, in the second example, the movable interconnector 500' is configured for selectively controlling and maintaining stable the spatial position and attitude of the docking port 410 during docking and undocking of the underwater vehicle 300 with respect to the surface vehicle 200, in particular with respect to the docking port 410, even where the surface vehicle 200 is stationary, i.e., where the surface vehicle 200 is not moving with respect to the water.

In the example of Fig. 15, the arm 520' comprises a single arm segment which moves as a rigid body about pitch axis PA.

In a variation of the second example, and referring to Fig. 16, the arm 520' comprises two arm segments 520A', 520B', each configured to move as a rigid body, and serially connected to one another via a motorized joint 520C The first arm segment 520A' is connected to the second arm platform 504' via third motorized joint 507', while the second arm segment 520B' includes the end 525 and thus carries the docking port 410 including the docking head 450. For example, the second arm segment 520B can be configured and operated to maintain the orientation of the docking port 510 constant (for example horizontal), irrespective of the movement of the first arm segment 520B, possible via the motorized joint 520C, and thus the first arm segment 520A' can be operated with a range of pitch angles Θ1, while the second arm segment 520B' can be operated with a different range of pitch angles Θ2 relative to the first arm segment 520A'. In yet other alternative variations of the second example, the arm 520' comprises a more than two arm segments, each arm segment configured to move as a rigid body, and serially connected to one another via a respective motorized joint.

Operation of the system 100' is similar to that the system 100, mutatis mutandis, with the main differences being that the surface vehicle 200 in the system 100' does not require (but can have) forward motion during docking/undocking procedures, and that the spatial position (i.e. depth) and attitude of the docking port 410 during docking and undocking of the underwater vehicle 300 with respect to the surface vehicle 200, in particular with respect to the docking port 410, is actively controlled.

In the method claims that follow, alphanumeric characters and Roman numerals used to designate claim steps are provided for convenience only and do not imply any particular order of performing the steps.

Finally, it should be noted that the word "comprising" as used throughout the appended claims is to be interpreted to mean "including but not limited to".

While there has been shown and disclosed examples in accordance with the presently disclosed subject matter, it will be appreciated that many changes may be made therein without departing from the spirit of the presently disclosed subject matter.




 
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