Patent Grant
8813669
This application relates generally to towed antenna systems and methods, and more particularly to systems and methods for communicating data signals to and from underwater craft to and from one or more remote communication systems.
When any underwater vehicle (UV), such as, for example, an unmanned underwater vehicle (UUV) or a submarine, is submerged under water, it cannot receive a GPS signal from a GPS satellite, and it cannot transmit or receive data signals over the air using radio frequency (RF) or satellite communication techniques. This lack of connectivity to the world above the surface of the water when submerged may significantly impact or constrain UV operations, and ultimately, the mission the UV may perform. Consequently, the ability to transmit and receive data signals may be beneficial to UV operations while a UV is submerged.
Unmanned underwater vehicles (UUVs), which are also known as autonomous underwater vehicles (AUVs), have been in use for some time. In particular, UUVs are known to be used to carry out missions involving intelligence, surveillance, and reconnaissance (ISR), mine countermeasures (MCM), anti-submarine warfare (ASW), time critical strike (TCS), inspection and identification, oceanography, oil and gas, payload delivery, and information operations, to name a few. UUVs are autonomous in the sense that, once launched on a mission, they operate according to a preprogrammed mission profile.
UUVs are also known to be formed from a series of interchangeable segments to permit flexibility in adding, subtracting or replacing entire hull segments of the UUV to tailor the UUV to a particular mission. UUVs are further known to have standardized hull diameters of, for example, 9 inches, 12¾ inches, and 21 inches. However, deployable and retrievable towable antenna systems configured for use in connection with a submerged UUV and which are capable of receiving GPS signals and transmitting and receiving RF (e.g., Wi-Fi, cellular, spread spectrum, etc.) and satellite data signals to and from the UUV and to and from aircraft (e.g., fixed wing manned and unmanned aircraft (including unmanned aerial vehicles and unmanned combat vehicles), cruise missiles, helicopters, and lighter than air craft such as balloons, etc.), spacecraft, watercraft (e.g., ships, boats, hovercraft, pontoons, buoys, beacons, and relays, etc.), and terrestrial locations are not known to exist aside from the instant disclosure.
Consequently, a towable antenna system of the type herein disclosed, which may be deployable and retrievable from and tethered to a UUV while the UUV is submerged, and which bi-directionally (i.e., transmit and receive simultaneously or sequentially in packets or without packets) communicates to and from the UUV and to and from, for example, air, space, and terrestrial communication systems via, for example, RF and satellite communication systems, as well as have the ability to receive GPS signals via GPS communication systems, may greatly enhance UUV operability and flexibility by permitting the UUV to remain submersed for longer periods than currently known UUV systems. In addition, a UUV having these capabilities and which is coupled with a towed antenna system designed to carry out communication to and from the UUV may be more maneuverable and controllable underwater (e.g., 3 to 5 meters below the surface) than it would be if, for example, the UUV were floating on the surface and subjected to waves and wind. A submerged UUV coupled to a towed antenna system may also minimize visibility of the overall UUV-towed antenna system during clandestine operations while allowing the UUV to continue its mission without having to resurface to obtain, for example, updated GPS position information.
A communication system is disclosed comprising an underwater vehicle configured for communicating with at least one remote communication system while the underwater vehicle is submerged, the underwater vehicle being connected to and configured for communicating with a towable body that is configured to communicate data signals to and from the underwater vehicle and to and from the at least one remote communication system while the underwater vehicle is submerged under water and while the towable body is deployed at or near the surface of the water.
In one embodiment, the underwater vehicle is an unmanned underwater vehicle. The underwater vehicle may be in communication with the at least one remote communication system and the towable body while the underwater vehicle is submerged under water and towing the towable body at or near the surface of the water.
The towable body may receive data signals from a global positioning system (GPS) reflecting a real time geographical position of the underwater vehicle. The towable body may transmit and receive data signals to and from at least one of the remote communication systems via at least one of an RF connection, a Wi-Fi connection, and a satellite connection.
In an embodiment, the at least one remote communication system comprises at least one of a GPS communication system, a satellite communication system, a Wi-Fi communication system, and an RF communication system.
In another embodiment, the underwater vehicle comprises a removably insertable towable antenna system, comprising a hull segment for connecting with at least one adjacent hull segment of the underwater vehicle, a launch and recovery system removably secured to the hull segment, where the launch and recovery system deploys and retrieves the towable body from and to the underwater vehicle, and a cable connecting the towable body to the launch and recovery system and connecting the launch and recovery system to the underwater vehicle. The cable transmits electrical power from a power source in the underwater vehicle to the towable body and transports data signals between the underwater vehicle and the towable body.
In one embodiment, the cable comprises a coaxial cable. The coaxial cable may include an inner conducting member and an outer conducting member, where the inner conducting member transmits electrical power from the underwater vehicle to the towable body and the outer conducting member transports data signals between the underwater vehicle and the towable body.
In another embodiment, the cable comprises a fiber optic cable. The fiber optic cable may include at least two optical fibers, where one optical fiber transmits electrical power from the underwater vehicle to the towable body and another optical fiber transports data signals between the underwater vehicle and the towable body.
A towable antenna system for an unmanned underwater vehicle is disclosed, comprising a launch and recovery system removably secured to the unmanned underwater vehicle, and a towable body tetheringly connected to the launch and recovery system by a cable that transports data signals between the towable body and the unmanned underwater vehicle. The towable body is configured for communicating with at least one remote communication system. Using the cable, the launch and recovery system retrievably deploys the towable body from a first position to a second position while the unmanned underwater vehicle is submerged under water to enable the unmanned underwater vehicle to communicate with the at least one remote communication system.
A profile of the towable body may approximately conform to an outer portion of the unmanned underwater vehicle when the towable body is in the first position. The towable body may be located at or near or on the surface of the water when the towable body is in the second position.
The towable body may include at least one communication system that receives and transmits data signals to and from the unmanned underwater vehicle and to and from the at least one remote communication system. In one embodiment, the at least one remote communication system includes at least one of a GPS communication system, a satellite communication system, a Wi-Fi communication system, and an RF communication system.
The towable antenna system may further include a hull segment removably connected with at least one adjoining hull segment of the unmanned underwater vehicle for housing the launch and recovery system and the towable body aboard the unmanned underwater vehicle. The cable may transmit electrical power to the towable body from the unmanned underwater vehicle.
A towable body for an underwater vehicle is disclosed, comprising a top section including at least one antenna for communicating with at least one remote communication system, and a bottom section connected to the top section. The bottom section comprises a cavity having at least one communication system removably housed therein for communicating with the at least one remote communication system through the at least one antenna and for communicating with the underwater vehicle.
The top section may include a profile that approximately conforms with at least a portion of an outer profile of the underwater vehicle when the towable body is in a stowed position relative to the underwater vehicle. The towable body may further include an antenna housing extending from a top surface of the top section and housing the at least one antenna to assist the at least one antenna in acquiring and maintaining at least one communication link with the at least one remote communication system while the towable body is at or near the surface of the water and while the underwater vehicle is submerged under the surface of the water.
The towable body may be deployable from a stowed position relative to the underwater vehicle while the underwater vehicle is submerged under water to a deployed position at or near the surface of the water to form at least one communication link between the at least one remote communication system and the underwater vehicle.
The towable body may further include a keel. The towable body may further include a rudder. In one embodiment, the rudder comprises a fixed position. In another embodiment, at least a portion of the rudder is movable side to side via at least one servo motor.
In an embodiment, the towable body is buoyant. The towable body may comprise a hydrodynamic lift-to-drag ratio greater than approximately 1.0 to enable the towable body to rise to the surface of the water when deployed from the underwater vehicle. In one embodiment, the towable body includes a circumferentially swept airfoil cross section.
In an embodiment, the at least one remote communication system comprises at least one of a GPS communication system, a satellite communication system, a Wi-Fi communication system, and an RF communication system. In another embodiment, the top section includes an aperture covered by a removably replaceable cap for providing access to the cavity of the towable body.
The bottom section and the top section may be separable and recombinable with one another. Alternatively, the bottom section is integratingly formed with the top section.
A launch and recovery system for a towable antenna system for use with an unmanned underwater vehicle is disclosed, comprising a drive system for retrievably deploying a towable antenna system to and from a unmanned underwater vehicle, and a launch and recovery communication system connected to the drive system for communicating data signals to and from the towable antenna system and the unmanned underwater vehicle and for transmitting power from the unmanned underwater vehicle to the towable antenna system, where the launch and recovery system is operable when submersed in water.
The drive system may include an electric motor operable on commands received from the unmanned underwater vehicle or the towable antenna system to deploy and retrieve the towable antenna system from and to the unmanned underwater vehicle and to and from the surface of the water. The drive system may also include a first end block releasably connected to a baseplate, the first end block forming a mount for the electric motor. The drive system may further include a first end cap connected to the first end block for forming a water-tight seal therebetween. The drive system may additionally include a first connector for connecting the drive system to a power source of the unmanned underwater vehicle, the connector forming a water-tight seal with the first end cap.
The launch and recovery communication system may include a slip ring assembly for communicating data signals to and from the towable antenna system and the unmanned underwater vehicle and for transmitting power from the unmanned underwater vehicle to the towable antenna system. The launch and recovery communication system may also include a second end block releasably connected to a baseplate, the second end block forming a mount for the slip ring assembly. The launch and recovery communication system may further include a second end cap connected to the second end block for forming a water-tight seal therebetween. The launch and recovery communication system may additionally include a second connector for connecting the launch and recovery communication system to a communication system of the unmanned underwater vehicle, the second connector forming a water-tight seal with the second end cap.
The launch and recovery system may further comprise a drum driven by the drive system, the drum configured to reel and unreel a cable thereon, the cable being connectable to the launch and recovery communication system on one end and to the towable antenna system on the other end, the cable being configured for transmitting electrical power from a power source in the unmanned underwater vehicle to the towable antenna system and for transporting data signals between the unmanned underwater vehicle and the towable antenna system.
For a better understanding of the invention, reference may be had to preferred embodiments shown in the following drawings in which:
Although the figures and the following disclosure describes an embodiment involving an unmanned underwater vehicle (UUV), one of ordinary skill in the art would know that the teachings of the disclosure would not be limited to use solely in connection with UUVs, and instead would appreciate that the teachings of the following disclosure would also apply to any submersible craft.
Turning now to the figures, wherein like reference numerals refer to like elements, there is illustrated in
UUV 20, through towed antenna system 40, may initiate and bi-directionally communicate with one or more of aircraft 12, watercraft 13, satellite 14, and terrestrial communication systems 16,18. Similarly, one or more of aircraft 12, watercraft 13, satellite 14, and terrestrial communication systems 16,18 may initiate and bi-directionally communicate with UUV 20 through towed antenna system 40. Bi-directional communication may simultaneously occur between UUV 20 and one or more of any or all of aircraft 12, watercraft 13, satellite 14, and terrestrial communication systems 16,18.
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Towed antenna system 40 also includes towed body 60 connected to cable system 48, which is connected to launch and recovery system 46, and which is ultimately connected at least electrically to the electronics and one or more power supplies housed in one or more modules 32 of UUV 20. Accordingly, cable system 48 is configured not only to act as a tether for deployment and retrieval of towed body 60 to and from UUV 20, but cable system 48 also serves the function of, for example, transporting electrical power to towed body 60 from UUV 20 and for transmitting data signals between towed body 60 and UUV 20. Such data signals may include, for example, real-time digital or analog video and voice signals as well as digital or analog data signals. In one embodiment, towed body 60 includes a camera for taking digital photographs and digital video, which may, for example, be streamed real-time to at least one of the remote communication systems. The taking of digital photographs and digital video may be autonomously performed according to a preprogrammed mission, or may be the result of a user remotely operating the camera in real-time via a communications link with towed antenna system 40.
Towed body 60 is further configured to house various antennas and associated electronics usable for receiving and transmitting data signals to and from UUV 20 and to and from aircraft 12, watercraft 13, satellite 14, and terrestrial communication systems 16,18 while UUV 20 is permitted to be submersed below the surface of the water.
As is shown in
Once towed body 60 is deployed at or near or on the surface of the water, towed antenna system 40 may autonomously attempt to open one or more communication channels to permit bi-directional communication with remote air, water, space, and terrestrial communication systems via, for example, RF and satellite methodologies. Once one or more communication channels are established between one or more remote air, water, space, and terrestrial communication systems, towed antenna system 40 may carry out bi-directional communication of data signals between such one or more remote air, water, space, and terrestrial communication systems and computer 155 onboard UUV 20. In this way, UUV 20 may remain completely submersed and hidden from view. In one embodiment, UUV 20 is submersed approximately 3-5 meters below the surface of the water when towed body 60 is deployed at the surface of the water.
Alternatively or additionally, towed antenna system 40 may autonomously attempt to receive GPS position data to update computer 155 onboard UUV 20 with updated actual geographical position information of UUV 20. Priority between one or more bi-directional communication channels or GPS data acquisition may be predetermined, such as, by knowing the predicted route that UUV 20 is programmed to make under water and knowing in advance what communication systems will likely be available at predetermined times of deploying towed body 60. Alternatively, computer 155 or a computer of towed antenna system 40 may cycle through available communication options or attempt to open all available communication options simultaneously. If multiple communication options are available at a given point in time, computer 155 or towed antenna system 40 may open all available communication channels or any number less than all available communication channels. Once at least one communication link is made with at least one remote communication system, remote control and operation of UUV 20 and towable system 40 may be made by a remote user.
To retrieve towed body 60 from a deployed position, launch and recovery system 46 may reverse the process and wind cable system 48 until towed body 60 is once again seated against hull segment 42 of towed antenna system 40. A locking mechanism may be provided to secure towed body 60 in its fully retracted position. To avoid overstretching cable system 48 during retrieval operations, launch and recovery system 46 may cease winding of cable system 48 when launch and recovery system senses, for example, a threshold resistance in cable system 48 or in launch and recovery system 46. In one embodiment, towed antenna system 40 includes proximity switch 214 to sense retraction of towed body 60 against hull segment 42. When proximity switch 214 is triggered, launch and recovery system 46 may cease winding of cable system 48.
To assist in the deployment and retraction of towed body 60, towed antenna system 40 may include cable guide 50 to guide cable system 48 neatly onto a drum or spool of launch and recovery system 46 and to guide cable system 48 during deployment of towed body 60. As shown in
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Antenna housing 66 may include one or more antennas, including GPS antenna 109 and satellite antenna 115, for example. Antenna housing 66 may also include an appropriate GPS receiver and/or an appropriate satellite receiver permanently potted within antenna housing 66. Antenna housing 66 may also include Wi-Fi antenna 127 and/or RF antenna 121. Antenna housing 66 may further include a Wi-Fi cable for connecting Wi-Fi antenna 127 to a Wi-Fi transceiver, which may be housed in electrical housing 62 secured in cavity 65 of bottom section 68 of towed body 60. Alternatively or additionally, antenna housing 66 may include a GPS/satellite cable connected to a GPS receiver and/or a satellite transceiver, both of which may be housed in electrical housing 62 in cavity 65 of bottom section 68 of towed body 60.
Top section 64, as shown in
Seal 92, which may be made from, for example, an elastomeric material, may be positioned between top section 64 and bottom section 68 to form a water-tight seal therebetween. In this way, top section 64 may be removably replaced with another top section 64 having a different antenna and communication hardware configuration stored therein.
Bottom section 68 also includes cavity 65 for positioning electrical housing 62. Electrical housing 62 is optional if the communications package is merely installed in cavity 65.
Antenna housing 66, as shown in
As shown in the figures, towed body 60 may comprise an airfoil shape to provide hydrodynamic lift during deployment under water. In one embodiment, the airfoil shape is based on a NACA5515 airfoil cross section. The airfoil cross sectional shape may be swept to match the shape of any diameter of UUV 20 to approximately conform towed body 60 to the contour of the outer surface of UUV 20. In this way, towed body 60 will allow UUV 20 to function as close to normal as possible during periods when towed body 60 is stowed, which could be up to approximately 94%, for example, of an entire UUV 20 mission.
In one embodiment, towed body 60 is buoyant to cause towed body 60 to float to the surface of the water on deployment from UUV 20 and to operate at or on the surface of the water to communicate with the at least one remote communication system. Towed body 60 may additionally be configured with a lift-to-drag ratio of greater than approximately 1.0 to permit towed body 60 to hydrodynamically “fly” to the surface of the water on deployment from UUV 20. In one embodiment, towed body 60 is configured with powered control surfaces that are movable via one or more servo motors, for example, to control towed body 60 while deployed under water and at or on the surface of the water. In another embodiment, towed body 60 is configured with powered control systems to propel and control towed body 60 while deployed under water and at or on the surface of the water. Towed body 60 may be made from any material that is lightweight, durable, and suitable for underwater use including salt water environments. In one embodiment, towed body 60 is made from a plastic. In another embodiment, towed body is made from a composite material. Rudder 76 of towed body 60 may be fixed or it may be moveable, for example, using one or more servo motors to permit additional directional control of towed body 60 during deployment under water and at or on the surface of the water. Access cap 84 may be removed from top section 64 to gain access to, for example, the electronics housed in cavity 65 of towed body 60. In this way, quick access to such contents may be obtained without having to disturb the water-tight seal between top section 64 and bottom section 68.
It should be understood by one of ordinary skill that a substantial portion of towed body 60 may be submerged, at least momentarily, while towed body 60 is at or on the surface of the water without causing loss of connectivity with the at least one remote communication system and without departing from the teachings of the instant disclosure. For example, top section 64 may be partially or completely submerged but, for example, the top of antenna housing 66 may remain above water thereby maintaining communications between the one or more antennae housed therein with the at least one remote communication system. In addition, towed body 60 may be completely submerged near the surface of the water and be in communication with the at least one remote communication system.
Turning now to
In the embodiment of
In another embodiment, cable system 48 comprises cable 252, as shown in
While all of the foregoing cable system 48 options would work in connection with towed antenna system 40, testing has shown that cable 282 may provide the potential for deeper deployments and higher underwater speeds of UUV 20 than can be achieved using cable 252 or cable 262, for example.
During experimental tests involving a simulated towed body 60, attached to cable 272, which has an approximately 0.26 inch diameter, it was shown that at 2 knots forward speed there was approximately 4 ounces of drag, while at 2.2 knots there were approximately 5 ounces of drag, and at 2.8 knots of forward speed, there was approximately 7 ounces of drag. These drag forces were in the range of what was predicted. Consequently, it is anticipated that cable 282, which is just under approximately 22% of the diameter of cable 272, would result in a fraction of these measured drag forces at these velocities. Consequently, while actual results in a real-life application may vary from the foregoing, the lower drag of cable 282 may provider operators of UUV 20 with a greater depth and speed envelope for UUV 20. In addition, the electrical components may also be simpler and less expensive than their fiber optic counterparts. Durability of cable 282 is also expected to be more rugged than many other options, including many fiber optics options, which may result in less down time, less repair operations, and better monitoring of operational status of UUV 20.
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Launch and recovery communication system 170 of launch and recovery system 46 may be configured for transmitting data signals to and from UUV 20 and towed body 60 and for transmitting electrical power from UUV 20 to towed body 60. Launch and recovery communication system 170 may include slip ring assembly 174 to electrically interface the stationary electrical components of launch and recovery communication system 170 of launch and recovery system 46 to the rotational electrical components of launch and recovery system 46.
Launch and recovery communication system 170 may further include underwater connector 184 for connecting cable system 48 to drum 210 while maintaining a water-tight seal. Launch and recovery communication system 170 may further include one or more bearings 180, and one or more rotary seals 182, to enable drum 210 to rotate relative to end block 186 while maintaining a water-tight seal therebetween.
Launch and recovery communication system 170 may additionally include end cap 178, which may be removable and replaceable to access internal components of launch and recovery communication system 170, such as, for example, slip ring assembly 174. Launch and recovery communication system 170 may also include end block 186, attached to base plate 212 for securing launch and recovery communication system 170 to hull segment 42 of towed antenna system 40. Launch and recovery communication system 170 may further include underwater connector 176 for transitioning cable system 48 from launch and recovery communication system 170 to connect with UUV 20 in a waterproof manner. In one embodiment, cable system 48 exiting underwater connector 176 comprises cable system 188, which connects with UUV 20. In another embodiment, cable system 48 comprises a continuous cable from originating at towed body 60 and terminating at UUV 20.
Launch and recovery system 46 may be made from materials suitable for submersion in salt water environments. In one embodiment, at least some of the components of launch and recovery system 46 are made from a plastic. In another embodiment, at least some of the components of launch and recovery system 46 are made from a composite material.
A simulated reel system 224 of launch and recovery communication system 220 was performed by modifying a fishing spool having a spool diameter of approximately 4.5 inches and adding approximately 30 sheet of a fiber optic tow cable, such as, for example, cable 252 or cable 262. A simple bail was fabricated and was manually driven around the stationery spool. The cable was unwound from the spool and then rewound onto the spool during which it was discovered that there was approximately a one-half turn of twist induced in the cable. However, when the cable was fully unwound from the spool, the twist disappeared. Further tests indicated that this behavior was repeatable.
In an embodiment, reel system 234 may be based on, for example, a Zeebaas ZX 27 fishing spool modified by removing the handle and adding coupling 238 for the spool to motor shaft interface. Reel system 234, like reel system 224, may comprise cable system 48 spun around a fixed spool with a bale type sheave rotating around the spool. In this way, cable system 48 may be coiled around the spool without the spool itself turning.
Turning now to
Towed body communication system 102, as shown in
As shown in
To receive GPS data signals, GPS communication system 107 of towed antenna system 40 may include a GPS antenna connected to a GPS receiver. GPS receiver of GPS communication system 107 may be connected to computer 105 using, for example, a USB, serial, or Ethernet cable. The GPS receiver may alternatively be integrated with or directly connected to computer 105.
To bi-directionally transmit and receive data signals to and from towed antenna system 40 to and from one or more remote communication systems via a satellite connection, satellite communication system 113 of towed antenna system 40 may include a satellite antenna connected to a satellite transceiver. The satellite transceiver of satellite communication system 113 may be connected to computer 105 via a serial cable, or a USB cable, for example. The satellite transceiver may alternatively be integrated with or directly connected to computer 105. The satellite antenna and the GPS antenna may comprise a single antenna configured to receive GPS signals and to transmit and receive data signals to and from one or more satellites. Similarly, the satellite transceiver and the GPS receiver may be configured as part of a single module having both satellite and GPS communication capabilities.
To bi-directionally transmit and receive data signals to and from towed antenna system 40 to and from one or more remote communication systems via an RF connection, RF communication system 119 of towed antenna system 40 may include an RF antenna connected to an RF transceiver. The RF antenna may be configured to receive and transmit, for example, UHF radio signals, including spread spectrum radio signals, and cellular communication signals.
As shown in
As further shown in
Cable system 48 (or cable system 188, for example) may be connected with Ethernet to Coax bridge 153 of UUV communication system 150 to convert the data signals to and from an Ethernet-based system to or from a coax cable system, such as, for example, cable 282. Ethernet to Coax bridge 153 may be connected with computer 155 either directly or, for example, using an Ethernet cable.
Also shown in
Computer 155 of UUV 20 may command launch and recovery system 46 to deploy and retrieve towed body 60 according to pre-programmed commands stored in computer 155. UUV 20 may transmit and receive communication signals to and from one or more remote communication systems using towed antenna system 40 to do so.
Data signals to and from the remote communication system with towed antenna system 40 may be transmitted to and from computer 155 of UUV 20 in real time. Alternatively or in addition to, data signals to and from the remote communication system with towed antenna system 40 may be stored in memory associated with computer 105. In this way, data signals from computer 155 of UUV 20 may be stored in memory associated with computer 105 for later transmission to the one or more remote communication systems. Similarly, data signals received from the one or more remote communication systems by towed antenna system 40 may be stored in memory associated with computer 105 for later transmission to computer 155 of UUV 20.
In an embodiment cable system 48 comprises a mini coax-type cable, such as cable 282, a Gumstix Verdex Pro XM4 or a Gumstix Verdex Pro XL6P may be employed. These devices, which are available at www.gumstix.com, are each a complete computer system that can accept multiple serial devices, has both wired and wireless Ethernet ports and runs the Linux operating system. It requires relatively low power to operate and it is literally the size of a stick of gum.
The Ethernet protocol is full duplex and high speed, but typically requires four conductor wires to transport data signals. To employ a two-wire protocol to permit cable system 48 to require only two conductors to transport data signals, an E-Linx Ethernet Extender may be employ. An E-Linx Ethernet Extender, which is available at www.www.bb-elec.com, permits Ethernet to operate over two wires and up to 50 MBPS for cable runs up to approximately 980 feet. An E-Linx Ethernet Extender may auto-negotiate its speed to maintain data integrity, eliminating the risk of data loss. In one embodiment, a Gumstix Verdex Pro XM4 may be connected to an E-Linx Ethernet Extender via the Ethernet port and housed in towed body 60. Within UUV 20, another E-Linx Ethernet Extender may be connected to computer 155 via its Ethernet port. A software bridge may be written to transport data signals between one or more serial ports and the Ethernet port.
In an embodiment cable system 48 comprises a fiber optic-type cable, such as cable 252, a PRIZM Ultimate USB may be employed to transmit and receive data signals along a single fiber. The PRIZM Ultimate USB, which is available at www.moog.com, offers bi-directional fiber optic transmission of, for example, video and data signals, over a single fiber. The PRIZM Ultimate USB is designed for underwater applications, and includes a 4 port USB 1.1 hub. This device may require up to 7.5 watts of power to operate, which may or may not be significant depending on the power source availability in UUV 20 or in towed body 60 and the power transmission properties of the chosen cable system 40. Two boards may be needed for the system to be complete: one board for each end of cable system 48.
Another option for use in connection with cable system 48 comprising a fiber optic-type cable is the AXFT-1621 single fiber, bi-directional receptacle/transceiver. This device, which is available from Axcen Photonics Corp. at www.axcen.com.tw, can transmit and receive data signals at the serial TTL level enabling compatibility with virtually any type of communications hardware. A second multiplexer board may be needed to combine data signals to and from Wi-Fi communication system 125, GPS communication system 107, satellite communication system 113, and RF communication system 119. The AXFT-1621 transceiver may incorporate additional multiplexers and provide breakouts for communications ports to attach additional communication modules, but may require custom supporting circuitry in order to function in towed antenna system 40.
In one embodiment, the Wi-Fi transceiver of Wi-Fi communication system 125 may be based on the RTL 8187B chipset found in, for example, a Trendnet TEW-424 UB Wi-Fi module, which is available at www.trendnet.com. This module operates with the standard IEEE 802.11g protocol, which may provide a range of approximately 100 meters for Wi-Fi communication. In addition, this particular module may connect directly into a USB port or a USB adaptor to computer 105, and is configured together with a Wi-Fi antenna.
In a test using this module for Wi-Fi communications, a simulated towed body 60 was placed in the water and a battery powered Wi-Fi router was carried approximately 12 feet above the water at various distances from the simulated towed body 60 carrying the Trendnet TEW-424 UB Wi-Fi module.
In addition, sample ping results while towing the simulated towed body 60 at site 4 shown in
In another embodiment, a NetWi-FiMicroSD Add-on board may be added to or be integrated with a Gumstix microcontroller to form a Wi-Fi transceiver. The NetWi-FiMicroSD, which is available at www.gumstix.com, features a 10/100 wired Ethernet port and a Marvell 88W8385 Wi-Fi transceiver module supporting IEEE 802.11b/g. This device also includes a MicroSD slot allowing up to 4 GB of flash memory to be used by the Gumstix microcontroller for logging or other file storage needs.
In an embodiment in which cable system 48 comprises a fiber optic-type cable, the Wi-Fi transceiver includes a WL-USB-RSMAP, which is available at www.jefatech.com. This module includes an SMA antenna jack to permit its use with a Wi-Fi amplifier to increase range.
In another embodiment, a Wi-Fi amplifier is connected between the Wi-Fi transceiver and the Wi-Fi antenna to amplify data signals received by and transmitted out from the Wi-Fi antenna. In an embodiment, the Wi-Fi amplifier comprises an RF-Linx 2400 CAE-1W, which is available at www.rflinx.com. This amplifier is a 1-watt amplifier, which uses automatic gain control to only use power when it needs to send or receive data, thereby conserving energy. Simulation testing has revealed that a Wi-Fi communications connection using this amplifier may result in a range of up to 1 mile over open water.
Turning to hardware options for GPS reception, in one embodiment, the GPS receiver of towed antenna system 40 includes one of the NovAtel OEMV 1/1G line of GPS receivers, which are available at www.novatel.com. The NovAtel OEMV 1/1G line offers centimeter-level positioning accuracy with RTK corrections and 2 meter or greater accuracy as well as high reliability using satellites in the GLONASS network. With 48+ satellites in the combined GPS-GLONASS networks, performance in high seas may be expected to be improved as more satellites are visible in the non-blocked portions of the sky. The OEMV-1 supports both RS232 and USB interfaces.
In one embodiment, the GPS antenna includes a PCtel WS3951-HR, which is available at www.canalgeomatics.com. This antenna provides high gain, low noise, low power and small size. It also has a high rejection, dual SAW filter, which is expected to decrease the risk of interference with any nearby Wi-Fi antenna.
In another embodiment, the GPS receiver includes a GlobalSat SiRF III transceiver module, which may track up to approximately 20 GPS satellites simultaneously. Data from this transceiver module is output in standard NMEA 0183 format over, for example, a USB interface.
When testing a simulated towed body 60 carrying this particular GPS transceiver module, the following results showed that the transceiver unit had a successful communications connection with one or more GPS satellites:
During testing, it was also discovered that the GPS communication connection may be lost or interrupted when the GPS antenna 109 in the simulated towed body 60 is submerged more than 1 inch below the water. However, GPS signal reacquisition occurred in a matter of approximately 2 seconds once the simulated towed body 60 returned to the surface. In a test involving a simulated towed body 60 configured with antenna housing 66 comprising a relatively short dorsal extension extending from top surface 64 (see, e.g., the exemplary towed body 60 shown in
Turning to options to communicate with one or more satellites, in one embodiment, the satellite transceiver of towed antenna system 40 includes the Iridium 9601, which is available at www.iridium.com. The Iridium 9601 transceiver is an OEM solution designed for embedded systems. It offers global coverage for the short-burst-data (SBD) service. The SBD service allows 340 bytes per message which is expected to work well for “phone-home” messages containing GPS coordinates and simple status updates from UUV 20. The Iridium 9601 interfaces with RS232 and uses an L-band antenna.
Turning now to
Towed body communication system 144 may include Ethernet switch 131 to transmit and receive data signals to and from Wi-Fi communication system 125, GPS communication system 107, satellite communication system 113, and RF communication system 119 to and from UUV communication system 150 of UUV 20. Ethernet switch 131 of towed body communication system 144 may be connected to Ethernet to Coax bridge 103 via, for example, Ethernet cable 159, to convert the data signals from an Ethernet-based system to cable system 48 comprising, for example, mini coax cable 282. Ethernet switch 131 may alternatively be integrated with Ethernet to Coax bridge 103 thereby simplifying connectivity with Wi-Fi communication system 125, GPS communication system 107, satellite communication system 113, and RF communication system 119. Depending on the configuration of launch and recovery system 46 used in connection with towed antenna system 40, towed body communication system 144 may also include, for example, launch and recovery communication system 170, 220, or 230.
To bi-directionally transmit and receive data signals to and from towed antenna system 40 to and from one or more remote communication systems via a Wi-Fi connection, Wi-Fi communication system 125 of towed antenna system 40 may include Wi-Fi antenna 127 connected to Wi-Fi amplifier 133 for amplifying data signals received by and/or transmitted out from Wi-Fi antenna 127. In one embodiment, Wi-Fi communication system 125 includes a Wi-Fi transceiver connected to Wi-Fi amplifier 133. The Wi-Fi transceiver may be connected to Ethernet to Wi-Fi bridge 139, which is usable for converting data signals to and from an Ethernet-based system. In another embodiment, UUV communication system 150 of UUV 20 includes a Wi-Fi transceiver for bi-directionally transmitting and receiving data signals to and from one or more remote communication systems to and from UUV 20 via a Wi-Fi connection.
As shown in the embodiment of
To bi-directionally transmit and receive data signals to and from towed antenna system 40 to and from one or more remote communication systems via a satellite connection, satellite communication system 113 of towed antenna system 40 may include satellite antenna 115 connected to satellite transceiver 114. Satellite transceiver 114 may be connected to Serial to Ethernet bridge 141 using, for example, serial cable 137. Serial to Ethernet bridge 141 may be connected to Ethernet switch 131 using, for example, Ethernet cable 159. Alternatively, Serial to Ethernet bridge 141 of satellite communication system 113 may be integrated with Ethernet switch 131 and/or Ethernet to Coax bridge 103.
To receive GPS data signals, GPS communication system 107 of towed antenna system 40 may include GPS antenna 109 connected to GPS receiver 108. GPS receiver 108 may be connected to Serial to Ethernet bridge 141 using, for example, serial cable 137. As shown in
To bi-directionally transmit and receive data signals via an RF connection to and from towed antenna system 40 to and from one or more remote communication systems via an RF connection, RF communication system 119 of towed antenna system 40 may include RF antenna 121 connected to RF amplifier 135 for amplifying data signals received by and transmitted out from RF antenna 121. In one embodiment, RF communication system 119 includes an RF transceiver connected to RF amplifier 135. The RF transceiver may be connected to Serial to Ethernet bridge 141, which is usable for converting data signals to and from an Ethernet based system. In another embodiment, UUV communication system 150 of UUV 20 includes an RF transceiver for bi-directionally transmitting and receiving data signals to and from one or more remote communication systems to and from UUV 20 via an RF connection. The RF transceiver or RF amplifier 135 may be connected to Serial to Ethernet bridge 141 using, for example, serial cable 137.
As shown in the embodiment of
Cable system 48 connects towed body communication system 144 with launch and recovery system 46. Cable system 48 or, for example, cable system 188, connects launch and recovery system 46 with computer 155 of UUV 20 contained in one of modules 32 of UUV 20.
Cable system 48 (or cable system 188, for example) may be connected with Ethernet to Coax bridge 153 of UUV communication system 150 to convert the data signals to and from an Ethernet-based system to or from a coax cable system, such as, for example, cable 282. Ethernet to Coax bridge 153 may be connected with computer 155 using, for example, Ethernet cable 159. Alternatively, Ethernet to Coax bridge 153 may be integrated with computer 155.
Electrical power from UUV 20 may be supplied through cable system 48 (or cable system 188, for example) through, for example, launch and recovery communication system 170 of launch and recovery system 46, and ultimately to towed body 60 through cable system 48. Alternatively, towed body 60 may house and carry its own power supply, such as a battery, to electrically power computer 105 and all peripheral computer and communication components and all servo motors in towed body 60.
Computer 155 of UUV 20 may command launch and recovery system 46 to deploy and retrieve towed body 60 according to pre-programmed commands stored in computer 155. UUV 20 may bi-directionally transmit and receive communication signals to and from one or more remote communication systems, in parallel or in series, using towed antenna system 40 to do so.
Data signals to and from the one or more remote communication system with towed antenna system 40 may be transmitted to and from computer 155 of UUV 20 in real time. Alternatively or in addition to, data signals to and from the one or more remote communication system with towed antenna system 40 may be stored in memory associated with computer 105. In this way, data signals from computer 155 of UUV 20 may be stored in memory associated with computer 105 for later transmission to the one or more remote communication systems. Similarly, data signals received from the one or more remote communication system by towed antenna system 40 may be stored in memory associated with computer 105 for later transmission to computer 155 of UUV 20.
In one embodiment, Ethernet to Wi-Fi bridge 139 comprises a Quatech Airborne Enterprise Class Ethernet bridge module, which is available at www.quatech.com. In another embodiment, GPS receiver 108 of GPS communication system 107 comprises, for example, a Hemisphere Crescent OEM module, which is available at www.hemispheregps.com. In a further embodiment, a GPS antenna 109 comprises a Wi-Sys WS3951-HR No-Interference Embedded GPS Antenna, which is available at www.antenna.com. In yet another embodiment, Serial to Ethernet bridge 141 comprises a Moxa NE-4100 Embedded Serial Device Server, which is available at www.moxa.com. In one embodiment, Ethernet switch 131 comprises a Moxa EOM-104 4-Port Embedded Managed Ethernet Switch, which is also available at www.moxa.com. In another embodiment, RF amplifier 135 comprises a Freewave MM2 900 MHz Spread Spectrum UHF Radio, which is available at www.freewave.com. In one embodiment, Ethernet to Coax bridge 103 comprises, for example, an Amplicon UCA-6120 Intelligent Ethernet to Coax Adaptor, which is available at www.amplicon.com. In another embodiment, satellite transceiver 114 of satellite communication system 113 comprises, for example, an Iridium 9602 SBD transceiver, which is available at www.iridium.com.
Typical UUV missions can last up to 18 hours in duration, during which towed antenna system 40 may be tasked with providing up to 50 deployments, each lasting from approximately 3 to approximately 8 minutes. In one embodiment, transmission and reception of data signals via satellite draws up to approximately 20 watts of power. The resulting energy capacity needed to operate an embodiment of towed antenna system 40 is approximately 133 watt-hours of energy. Therefore, an exemplary towed antenna system 40 may either require a battery with 133 watt-hour capacity, or cable system 48 must be sized to transmit approximately 20 watts from UUV 20's own power supply.
In an embodiment involving cable system 48 comprising a fiber optic-type cable, to transmit electrical power over fiber, a JDSU Photovoltaic power converter may be used. This unit delivers 0.5 watts of energy at voltages ranging between 2 and 12 volts DC. Although this may not be enough energy to simultaneously power all of the electrical devices located in towed body 60, this device may nevertheless be used to trickle charge a battery housed in towed body 60 between deployments.
In one embodiment having the hardware listed below for cable system 48 comprising a fiber optic-type cable, and assuming a deployment duration of approximately 8 minutes for towed antenna system 40, each device may be expected to demand the following amounts of electrical energy:
To accommodate these electrical loads, in one embodiment, a 7.4 V Li—Po battery having 875 mAh of capacity may be employed. A battery of this type is expected to weigh only 1.6 oz. and would provide 6.5 W-hrs, which is expected to be more than three times the needed capacity.
A power control board may be used to regulate the charging of the battery and distribution of power to the different system components. If the Axcen AXFT-1621 fiber optic module were included in the system, charging circuitry could be incorporated into its circuit board as well. Otherwise, a small PCB incorporating a single chip charging regulator may be built.
In an embodiment having the hardware listed below for cable system 48 comprising a mini-coax-type cable, and assuming a deployment duration of approximately 8 minutes for towed antenna system 40, each device may be expected to demand the following amounts of electrical energy:
In this embodiment, the maximum current required is therefore approximately 1.36 amps. Taking, for example, cable 282, which may be rated to transmit only approximately 0.2 amps, the voltage may need to be stepped up to approximately 38.5 volts to provide enough power to system components. A DC-DC converter may be employed to step the voltage down to any level required by any electrical component of towed antenna system 40. In addition, a passive filter located in towed body 60 may be employed to separate out the DC power from any data signals.
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the disclosure herein is meant to be illustrative only and not limiting as to its scope and should be given the full breadth of the appended claims and any equivalents thereof.
This application claims priority from U.S. Provisional Patent Application Ser. No. 61/268,439, filed Jun. 12, 2009, which is incorporated herein in its entirety by reference.
The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Contract No. N00014-09-M0038 awarded by the U.S. Department of Defense.
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| Number | Date | Country | |
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| 61268439 | Jun 2009 | US |
