Unmanned submersible vehicles and methods for operating the same in a body of liquid

1. An unmanned submersible vehicle for use in a body of liquid having a top surface and in air overlying the top surface, the vehicle comprising:

a hull having first and second opposed ends, the hull including a first hull portion adjacent the first end and a second hull portion adjacent the second end, wherein the hull is elongated and defines a longitudinal axis;

an integral antenna disposed within the first hull portion;

a mass distribution system including a mass member within the hull, the mass distribution system being operable to move the mass member along the longitudinal axis away from and toward the antenna; and

an antenna positioning system configured to reorient the hull from a transit position to a signal position, wherein, when the hull is in the signal position:

the first hull portion and the antenna are disposed above the second hull portion a greater vertical distance than when the hull is in the transit position;

the first hull portion and the antenna are disposed above the top surface and in the air while at least the second hull portion remains submerged in the body of liquid; and

the antenna is disposed entirely in the hull and is operative to emit signals through the air above the top surface without obstruction by the body of liquid and/or to receive signals through the air above the top surface without obstruction by the body of liquid, wherein the signals are emitted and/or received by the antenna within the hull.

2. The vehicle of claim 1 wherein:

the vehicle has a center of buoyancy (CB) and a center of mass (CM);

the antenna positioning system is configured to reorient the hull from the transit position to the signal position by changing pitching moments tending to counteract CB and CM-induced moments during transit, changing the buoyancy of the vehicle and/or altering the position of at least one of the CB and the CM; and

when the hull is in the signal position, the CB is located vertically above the CM.

3. The vehicle of claim 2 the antenna positioning system is configured to reorient the hull by altering the relative positions of the CB and the CM within the hull.

4. The vehicle of claim 2 wherein the antenna positioning system is configured to reorient the hull by altering the position of at least one of the CB and the CM with respect to the hull.

5. The vehicle of claim 2 wherein the antenna positioning system is configured to reorient the hull by altering the buoyancy of the vehicle.

6. The vehicle of claim 5 including a flood tank, wherein the antenna positioning system is configured to reorient the hull from the transit position to the signal position by altering an amount of the liquid from the body of liquid in the flood tank to thereby controllably alter the buoyancy of the vehicle.

7. The vehicle of claim 2 wherein the antenna positioning system is configured to reorient the hull by changing a pitching moment.

8. The vehicle of claim 1 including a propulsion system to forcibly and controllably drive and steer the vehicle through the body of liquid in the transit position and/or down into the body of liquid from the signal position to fully submerge the hull in the body of liquid.

9. The vehicle of claim 1 including a sensing device mounted on and/or in the hull to sense a parameter external to the vehicle.

10. The vehicle of claim 1 including a communications device operably connected to the antenna to generate and/or receive and process signals propagated through the air over the top surface.

11. The vehicle of claim 1 wherein:

the longitudinal axis is substantially horizontal when the hull is in the transit position; and

the longitudinal axis is substantially vertical when the hull is in the signal position.

12. The vehicle of claim 1 wherein the vehicle is not tethered to another object.

13. The vehicle of claim 12 including a propulsion system to forcibly and controllably drive and steer the vehicle through the body of liquid in the transit position and/or down into the body of liquid from the signal position to fully submerge the hull in the body of liquid.

14. The vehicle of claim 1 wherein the signals are radio waves.

15. A communications system for use in a body of liquid having a top surface and in air overlying the top surface, the communications system comprising:

a plurality of unmanned submersible vehicles adapted to be distributed in the body of liquid, each of the vehicles including:

a hull having first and second opposed ends, the hull including a first hull portion adjacent the first end and a second hull portion adjacent the second end, wherein the hull is elongated and defines a longitudinal axis;

an integral antenna disposed within the first hull portion;

a mass distribution system including a mass member within the hull, the mass distribution system being operable to move the mass member along the longitudinal axis away from and toward the antenna;

an antenna positioning system configured to reorient the hull from a transit position to a signal position, wherein, when the hull is in the signal position:

the first hull portion and the antenna are disposed above the second hull portion a greater vertical distance than when the hull is in the transit position;

the first hull portion and the antenna are disposed above the top surface and in the air while at least the second hull portion remains submerged in the body of liquid; and

the antenna is disposed entirely in the hull and is operative to emit signals through the air above the top surface without obstruction by the body of liquid and/or to receive signals through the air above the top surface without obstruction by the body of liquid, wherein the signals are emitted and/or received by the antenna within the hull; and

a communications device operably connected to the antenna to generate and/or receive and process signals propagated through the air over the top surface.

16. A method for operating an unmanned submersible vehicle, the method comprising:

providing an unmanned submersible vehicle for use in a body of liquid having a top surface and in air overlying the top surface, the vehicle including:

a hull having first and second opposed ends, the hull including a first hull portion adjacent the first end and a second hull portion adjacent the second end, wherein the hull is elongated and defines a longitudinal axis;

an integral antenna disposed within the first hull portion;

a mass distribution system including a mass member within the hull, the mass distribution system being operable to move the mass member along the longitudinal axis away from and toward the antenna;

an antenna positioning system configured to reorient the hull from a transit position to a signal position; and

using the antenna positioning system, reorienting the hull from a transit position to a signal position, wherein, when the hull is in the signal position:

the first hull portion and the antenna are disposed above the second hull portion a greater vertical distance than when the hull is in the transit position;

the first hull portion and the antenna are disposed above the top surface and in the air while at least the second hull portion remains submerged in the body of liquid; and

the antenna is disposed entirely in the hull and is operative to emit signals through the air above the top surface without obstruction by the body of liquid and/or to receive signals through the air above the top surface without obstruction by the body of liquid, wherein the signals are emitted and/or received by the antenna within the hull.

17. The method of claim 16 including reorienting the hull from the transit position to the signal position by changing pitching moments tending to counteract CB and CM-induced moments during transit, changing the buoyancy of the vehicle and/or altering the position of at least one of the CB and the CM, wherein, when the hull is in the signal position, the CB is located vertically above the CM.

18. The method of claim 17 including reorienting the hull from the transit position to the signal position by altering the relative positions of the CB and the CM within the hull.

19. The method of claim 17 including reorienting the hull from the transit position to the signal position by altering the position of at least one of the CB and the CM with respect to the hull.

20. The method of claim 17 including reorienting the hull from the transit position to the signal position by altering the buoyancy of the vehicle.

21. The method of claim 16 wherein the vehicle includes a propulsion system and including forcibly and controllably driving and steering the vehicle through the body of liquid in the transit position using the propulsion system.

22. The method of claim 16 wherein the vehicle includes a propulsor and including forcibly driving the vehicle down into the body of liquid from the signal position using the propulsor to fully submerge the hull in the body of liquid.

23. The method of claim 16 including sensing a parameter external to the vehicle using a sensing device mounted on and/or in the hull.

24. The method of claim 16 including generating and/or receiving and processing signals propagated through the air over the top surface using a communications device operably connected to the antenna.

25. The method of claim 16 including propelling the vehicle through the body of water in a fully submerged condition while in the transit position, wherein:

the longitudinal axis is substantially horizontal when the hull is in the transit position; and

the longitudinal axis is substantially vertical when the hull is in the signal position.

26. The method of claim 16 wherein the vehicle is not tethered to another object.

27. The method of claim 26 wherein the vehicle includes a propulsion system and including forcibly and controllably driving and steering the vehicle through the body of liquid in the transit position using the propulsion system.

28. A method for operating an unmanned submersible vehicle, the method comprising:

providing an unmanned submersible vehicle for use in a body of liquid having a top surface and in air overlying the top surface, the vehicle including:

a hull having first and second opposed ends, the hull including a first hull portion adjacent the first end and a second hull portion adjacent the second end, wherein the hull is elongated and defines a longitudinal axis;

an integral antenna disposed within and/or mounted on the first hull portion;

an antenna positioning system configured to reorient the hull from a transit position to a signal position, the antenna positioning system comprising a propulsion system, a mass distribution system, and a buoyancy control system, wherein:

the propulsion system includes a propulsor, the propulsion system being operable to actively displace fluid to drive the vehicle through the body of liquid;

the mass distribution system includes a mass member within the hull, the mass distribution system being operable to move the mass member along the longitudinal axis away from and toward the antenna; and

the buoyancy control system is operable to alter the net buoyancy of the vehicle between a minimum buoyancy and a maximum buoyancy;

using the buoyancy control system, maintaining the vehicle submerged in the transit position and, with the vehicle in the submerged transit position, driving the vehicle in the body of liquid using the propulsion system; and

using the antenna positioning system, reorienting the hull from the transit position to the signal position, wherein, when the hull is in the signal position:

the first hull portion and the antenna are disposed above the second hull portion a greater vertical distance than when the hull is in the transit position;

the first hull portion and the antenna are disposed above the top surface and in the air while at least the second hull portion remains submerged in the body of liquid; and

the antenna is operative to emit signals through the air above the top surface and/or to receive signals through the air above the top surface;

wherein reorienting the hull from the transit position to the signal position includes:

using the buoyancy control system, increasing the net buoyancy of the vehicle to substantially the maximum buoyancy to cause the vehicle to ascend; and

using the mass distribution system, moving the mass member longitudinally to a distal position away from the antenna, thereby shifting the center of mass of the vehicle away from the antenna.

29. The method of claim 28 , including:

after reorienting the hull from the transit position to the signal position, using the antenna positioning system to reorient the hull from the signal position to the transit position, including:

using the buoyancy control system, decreasing the net buoyancy of the vehicle to less than the maximum buoyancy to cause the vehicle to descend; and

using the mass distribution system, moving the mass member longitudinally away from the distal position and toward the antenna, thereby shifting the center of mass of the vehicle toward the antenna; then

using the buoyancy control system, maintaining the vehicle submerged in the transit position and, with the vehicle in the submerged transit position, driving the vehicle in the body of liquid using the propulsion system; and then

using the antenna positioning system, reorienting the hull from the transit position to the signal position, wherein reorienting the hull from a transit position to a signal position includes:

using the buoyancy control system, increasing the net buoyancy of the vehicle to substantially the maximum buoyancy to cause the vehicle to ascend; and

using the mass distribution system, moving the mass member to the distal position away from the antenna, thereby shifting the center of mass of the vehicle away from the antenna.

30. The method of claim 28 wherein, in the signal position, the antenna is disposed entirely in the hull and is operative to emit signals through the air above the top surface without obstruction by the body of liquid and/or to receive signals through the air above the top surface without obstruction by the body of liquid.