Multi-functional cellular surface for underwater vehicles

STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefore.

CROSS-REFERENCE TO RELATED APPLICATIONS

There are no related patent applications.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates generally to sensors and weapons for underwater vehicles, and more particularly to a suite of cellular sensors and weapons forming an outer surface, or skin, of an underwater vehicle.

(2) Description of the Prior Art

Currently, underwater vehicles used in surveillance, target detection and acquisition and/or in defensive and offensive engagements are fitted with various sensor suites and weapons. The sensor suites may include acoustic, electromagnetic, thermal and photo-optical sensors that are, in many instances, mounted on the outer surface of the vehicle and require physical connection to the vehicle. At times, it becomes advantageous to deploy sensors or arrays of sensors at appreciable distances from the vehicle. In some instances, the sensors can be placed in areas where the vehicle could not operate so as to provide a standoff capability to the vehicle. Further, the separation between the sensors and the vehicle can provide for increased signal detection and identification. In order to deploy such sensors, they may be placed in position by the vehicle, they may be launched from the vehicle, or they may be let out from the vehicle on tethers. Placing the sensors in position exposes the vehicle to possibly hostile environments. Launching the sensors or letting them out on tethers generates acoustic transients that may subject the vehicle to detection by adversaries.

Weapons are typically carried internal to the vehicle and are launched through ports in the outer surface. Launching such weapons will typically require opening the appropriate port, ejecting the weapon into the surrounding medium and closing the port once the weapon is clear. As with sensor launching and tethering, the opening and closing of weapons ports and the ejection of the weapons generate acoustic transients that may be detectable by potential adversaries. Remote deployment of weapons from the vehicle suffers from the same concerns as does remote sensor deployment. Further, in many engagement scenarios, it may not be possible to deploy remote sensors to assist in directing the weapon to a target.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide sensors for an underwater vehicle that can be deployed without exposing the vehicle to hostile environments.

Another object of the present invention is to provide sensors for an underwater vehicle that can be deployed while generating minimal acoustic gradients.

Still another object of the present invention is to provide weapons for an underwater vehicle that can also be deployed while generating minimal acoustic gradients.

A further object of the present invention is to provide a system of sensors and weapons for an underwater vehicle that share deployment characteristics.

A still further object of the present invention is to provide a system of sensors and weapons that can be remotely deployed and maintain communication with the vehicle and with each other.

Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings.

In accordance with the present invention, a system of sensors and weapons for an underwater vehicle is provided that is attached to the outer surface of the vehicle. The sensors and weapons are in the form of individual cells, with each cell engineered to have specific functional capabilities, e.g., acoustic sensor cells, electromagnetic sensor cells, communications cells, control cells and munitions cells. A layer of cells is arranged on the outer surface of the vehicle and each cell is electromagnetically coupled to the surface so as to cover the vehicle. The cells form a multi-functional cellular surface, or skin, over the vehicle surface. Further layers of cells can be added over previous layers, depending on the capabilities desired. The arrangement of cells within each layer will also be dependent on the desired capabilities and the overall mission of the vehicle. For example, a vehicle used solely for surveillance may have only sensor and communications cells. Each cell has a unique identity known to the vehicle such that cells may be individually deployed from the vehicle by decoupling the identified cell from the vehicle. The unique identity also allows a cell to return to its appropriate position on the vehicle when desired. One or more types of cells are engineered to be mobile. Once decoupled, these motive cells can transport themselves and other cells as necessary, to positions remote from the vehicle. Thus the vehicle can remain clear of a hostile environment while deploying sensors and/or weapons cells into the environment.

The system described provides sensors and weapons that are deployed from an underwater vehicle with minimal acoustic gradient generation. The cells are merely electromagnetically decoupled from the vehicle, without requiring port openings or launch systems. The system includes both sensor and weapons cells that can be deployed simultaneously. By further deploying appropriate communications cells, the sensor cells communicate target location information to the weapons cells to assist in acquiring targets.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the invention and many of the attendant advantages thereto will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein like reference numerals refer to like parts and wherein:

FIG. 1

is a side view of an underwater vehicle covered with a multi-functional cellular skin;

FIG. 2

is an enlarged view of a portion of multi-functional cellular skin;

FIG. 3

is an illustrative view of a portion of the vehicle deploying a number of cell into the surrounding medium;

FIG. 4

is a cross-sectional view of multiple layers of multi-functional cellular skins taken at

4

—

4

of

FIG. 2

; and

FIGS. 5A-5D

are illustrative block diagrams for various cell types.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to

FIG. 1

, there is shown a side view of an underwater vehicle

10

, covered by a skin

12

consisting of multi-functional cells

14

. Cells

14

are arranged to completely cover vehicle

10

and conform to the underlying shape of vehicle

10

. The cells are electromagnetically coupled to vehicle

10

and groups of cells

14

can be configured to form various arrays to provide vehicle

10

with acoustic and electromagnetic sensing, communications and weapons capabilities. When coupled to vehicle

10

as shown in

FIG. 1

, each cell

14

is linked to vehicle

10

in such a manner that vehicle

10

can identify the location and function of the individual cells

14

. Thus, signals coming from one or more cells

14

are properly interpreted by vehicle

10

. Further, electromagnetic waves can be utilized to provide power to cells

14

and to program/reprogram individual cells

14

.

FIG. 2

is an enlarged view of a portion of the skin

12

more clearly showing individual cell types

14

A-

14

D. In the embodiment shown in

FIG. 2

, cells

14

A are acoustic sensing cells. Cells

14

A can be grouped to form acoustic sensor suites. Cells

14

B are electromagnetic cells (EM cells), capable of both sensing and emitting electromagnetic signals and forming radio frequency sensor networks. Thus cells

14

B can provide communications, Intelligence Surveillance and Reconnaissance (ISR) and Electronic Surveillance Measures (ESM) capabilities to vehicle

10

. Cells

14

C are munitions or weapons cells. Cells

14

D are referred to as maternal cells that provide control to other cells, i.e., cells

14

D provide communications between cells

14

and between cells

14

and vehicle

10

, cells

14

D may reprogram the functions of other cells

14

, including activation and deactivation of other cells

14

, and they may provide additional energy supply to other cells

14

. Cells

14

D are also mobile and can link with one or more cells

14

to transport the cells

14

to a desired location.

Referring now to

FIG. 3

, there is shown a large number of cells

14

being deployed from vehicle

10

. Using its knowledge of the location and function of each cell

14

, vehicle

10

decouples those cells

14

appropriate for the particular mission to be accomplished. If the cells

14

are decoupled as vehicle

10

is traveling through the surrounding medium, decoupled cells

14

will ablate from vehicle

10

. If vehicle

10

is stationary, maternal cells

14

D can be utilized to transfer other cells

14

away from vehicle

10

. In either situation, vehicle

10

can deploy sensors, weapons, or communications capabilities with minimum acoustic gradient generation.

In the illustrative example of

FIG. 3

, the mission is to seek, identify and disable a remote threat. Thus, one or more arrays of cells

14

A are released to monitor acoustic signals from the threat so as to determine its position and identify the threat based on its acoustic signature. Maternal cells

14

D are released in conjunction with acoustic cells

14

A to maneuver cells

14

A into position and to control their operation. Maternal cells

14

D may orient cells

14

A so as to maximize the exploitation of environmental conditions to maximize the acoustic performance of cells

14

A. Maternal cells

14

D are also released in conjunction with weapons cells

14

C. Once the threat is located and identified, maternal cells

14

D can transport cells

14

C to the threat location and control their activation, so as to disable the threat. Electromagnetic (EM) cells

14

B are released to provide additional sensing capabilities and communications with vehicle

10

. Maternal cells

14

D may also be associated with cells

14

B as necessary to transport and control cells

14

B.

Another aspect of the cells

14

each having a unique identifier known to vehicle

10

relates to the attachment of skin

12

over vehicle

10

. Cells

14

that have been deployed can be brought back to vehicle

10

and coupled back to vehicle

10

in their original position. In a similar manner, in first constructing skin

12

over vehicle

10

, vehicle

10

may be immersed in a cell matrix. The cells

14

would couple to vehicle

10

in accordance with their known placement, thus “growing” skin

12

over vehicle

10

. Additional layers can be similarly “grown”.

Referring now to

FIG. 4

, there is shown a partial cross-section of vehicle

10

and skin

12

taken at line

4

-

4

of FIG.

1

. It is seen in

FIG. 4

that skin

12

is composed of a number of layers

12

A-

12

N of cells

14

. Each layer

12

n may have a unique distribution of cell types

14

A-

14

D, or the cells

14

of adjacent layers may have corresponding cell types

14

A-

14

D, as shown for layers

12

A and

12

B. Thus, if groups of cells

14

are deployed from layer

12

A, corresponding cells in layer

12

B are exposed. These corresponding cells

14

of layer

12

B may then be utilized to restore full functionality to the skin

12

configuration of layer

12

A. If the layers do not have corresponding cells

14

, vehicle

10

can reconfigure the skin

12

functionality based on its knowledge of the locations and functions of exposed cells

14

.

Referring to

FIGS. 5A-5D

, the cell types

14

A-

14

D will be described in further detail.

FIG. 5A

illustrates an acoustic cell

14

A. Cell

14

A includes one or more acoustic sensors

20

, an electronics module

22

and an acoustic power module

24

. When cell

14

A is coupled to vehicle

10

, sensors

20

and electronics module

22

operate generally in the manner of existing hull mounted acoustic sensors and their associated electronics. The electromagnetic coupling of cell

14

A with vehicle

10

(as indicated by double arrow

26

in

FIG. 4

) provides the linkage between cell

14

A and signal processing modules

28

in vehicle

10

(FIG.

4

). However, when decoupled from vehicle

10

, electronics module

22

provides a link between cell

14

A and one or more maternal cells

14

D. As noted previously, each cell

14

has a unique identifier. The identifier is maintained within electronics module

22

such that outgoing signals are coded with the identifier and only linkages having the proper identifier for cell

14

A can be established. In order to minimize the cost and complexity of cells

14

, self-contained processing is minimized. Thus, in a preferred embodiment, each acoustic cell

14

A is tuned to a particular threat frequency band. Upon sensing a signal in the band it is tuned to, an acoustic cell

14

A sends an active acoustic signal to its associated maternal cell

14

D to alert maternal cell

14

D of the detection.

Cell

14

B, as illustrated in

FIG. 5B

, includes sensor/emitter

30

and EM power module

32

. As with acoustic cell

14

A, the cell identifier is maintained within the electronics of sensor/emitter

30

. Sensor/emitter

30

further detects changes in magnetic fields, with the detection threshold adjusted to be sensitive to changes indicative of a large, metallic, underwater body. For communications, ISR and ESM capabilities, EM cell

14

B would need to be on the surface of the water. Thus, cell

14

B may further include flotation device

30

a

, which, when activated, causes cell

14

B to float to the surface. Flotation device

30

may be any well-known device, such as flotation bag inflated by a solenoid-activated compressed air cylinder. Once on the surface, sensor/emitter

30

can provide short burst emissions for satellite communications, or communications to other nearby platforms. As with cells

14

A arrayed beneath the surface, cells

14

B may be arrayed on the surface to form a floating aperture capable of robust transmissions.

Referring to

FIG. 5C

, cell

14

C, as illustrated therein, includes weapons sensor/trigger

40

and munitions

42

. Sensor/trigger

40

operates in the manner of existing munitions triggers, e.g., proximity sensors, magnetic sensors, pressure sensors, etc. Additionally, sensor/trigger

40

maintains the unique identifier for cell

14

C, such that it is responsive to signals from vehicle

10

or maternal cells

14

D having the proper identifier. Upon sensing the appropriate signal, either directly from the environment, from vehicle

10

or from a maternal cell

14

D, sensor/trigger

40

causes munitions

42

to activate.

FIG. 5D

illustrates a maternal cell

14

D. Maternal cell

14

D includes communications module

50

, one or more maternal power modules

52

and one or more thrusters

54

. Communications module

50

maintains communication with other cells

14

and serves as the main link to vehicle

10

for a group of cells

14

under control of maternal cell

14

D. Module

50

maintains the unique identifier for cell

14

D and further includes command-processing capabilities to interpret and carry out instructions from vehicle

10

, as well as maintain an internal clock. For the scenario previously described, module

50

would store the unique identifiers for the cells under its control, thus enabling communications with each cell that can be both time and identifier stamped. The processing capabilities of module

50

allow control of thrusters

54

to properly position the group of cells

14

for the mission received from vehicle

10

. For example,

FIG. 3

illustrates a group of cells

14

′ released from vehicle

10

and under the control of maternal cell

14

D′. During transport to their final positions, cells

14

′ are electromagnetically coupled to maternal cell

14

D′. Maternal cell

14

D′, together with coupled cells

14

′, proceeds to the mission location as directed by vehicle

10

. As each of the cells

14

′ arrives at its directed location, it is decoupled from maternal cell

14

D′. The remaining coupled cells are then transported to the next cell location until all cells are properly positioned. The processing capability of module

50

would include inertial guidance capabilities such that no communication with vehicle

10

is needed to accomplish the cell placements once the group of cells

14

′ have decoupled from vehicle

10

. Maternal communications module

50

further receives and relays signals between vehicle

10

and cells

14

′.

As previously mentioned, processing capabilities of cells

14

would need be minimized to reduce costs and complexity of cells

14

. Referring to the example of

FIG. 3

, a maternal cell

14

D would receive a detection alert from one or more cells

14

A. Onboard processing at module

50

would limit false alarms by only relaying the threat alertment to vehicle

10

after a pre-determined threshold of alertments from a pre-determined number of cells

14

A. The threat alertment to vehicle

10

would include the location of the cells

14

A and the threat frequency band detected.

The invention thus described is system of sensors and weapons for an underwater vehicle. The sensors and weapons are in the form of individual cells and are electromagnetically attached to the outer surface of the vehicle, forming a skin about the vehicle. Each cell is engineered to have specific functional capabilities, e.g., acoustic sensor cells, electromagnetic sensor cells, communications cells, control cells and munitions cells. The arrangement of cells and the number of layers of cells depend on the capabilities desired. Each cell has a unique identity known to the vehicle such that cells may be individually deployed from the vehicle by decoupling the identified cell from the vehicle. Deployment of the cells does not require any port openings or launch system, as the cells are electromagnetically decoupled from the vehicle and allowed to ablate from the surface. Groups of cells can be deployed to specific locations and arrayed in specific configurations by motive cells, allowing the vehicle to remain in a standoff position. The ability to arrange sensor cells into desired configurations remote from the vehicle allows the formation of variable aperture arrays, enhancing the vehicle's sensing capabilities.

Although the present invention has been described relative to a specific embodiment thereof, it is not so limited. Cells

14

have been illustrated having a triangular shape. It is understood that the shapes and sizes of individual cells

14

may be varied to suit the vehicle

10

and its functionality. The listing of cell types is not intended to be exhaustive. Cell types may be combined into single cells or functionalities may be added to cells, e.g., acoustic cells

14

A may be provided with thrusters

54

, or sensors

20

may include velocity, temperature, optical, or other sensing capabilities. Additionally new cell types, such as countermeasure cells

14

E (FIG.

2

), can be fabricated for specific needs.

FIG. 4

depicts multiple layers

12

A-

12

N of skin

12

and

FIG. 1

illustrates skin

12

fully covering vehicle

10

. The number of layers as well as the extent of each layer may also be varied to suit the expected mission of the vehicle and to suit specific vehicle configurations.

Thus, it will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.