Patent Publication Number: US-10322782-B1

Title: Combined autonomous underwater vehicle and buoy device

Description:
STATEMENT OF GOVERNMENT INTEREST FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     The United States Government has ownership rights in this invention. Licensing inquiries may be directed to Office of Research and Technical Applications, Space and Naval Warfare Systems Center, Pacific, Code 72120, San Diego, Calif. 92152; telephone (619) 553-5118; email: ssc_pac_t2@navy.mil. Reference Navy Case No. 103881. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This disclosure relates generally to a long term oceanic buoy that operates as an autonomous underwater vehicle when being deployed. 
     Description of the Prior Art 
     The use of buoys in various aquatic operations is well established. As many buoys are not operative to travel to their desired location on their own, buoys are commonly required to be transported on other vessels to desired location in order to be deployed. As such, a problem which still exists is that deploying buoys and other oceanic monitoring equipment can be extreme costly in ship time and/or ship personnel time. 
     Thus, there remains a need for a device that allows a user desiring to deploy a buoy in a remote location to merely deploy a combined autonomous underwater vehicle and buoy device from shore and have it navigate to a specified location and then invert and become a stationary buoy. 
     SUMMARY OF THE INVENTION 
     The present disclosure describes a combined autonomous underwater vehicle and buoy device (or “combined buoy device”) that allows for relatively inexpensive deployments and recoveries of the combined buoy device, as well as easy repositioning if the buoy device drifts out of an area of interest. In accordance with an embodiment of the present disclosure, the combined buoy device comprises a device body having a proximal end and a distal end, wherein said proximal end defines a bow when the device body is in a horizontal orientation and said distal end defines a stern when the device body is in the horizontal orientation; wherein said device body is configured to selectively cause an increase in the buoyancy of the device body so as to cause the device body to descend vertically and to cause a decrease in the buoyancy of the device body so as to cause the device body to ascend vertically; wherein said device body is configured to generate lift that moves the device body horizontally in response to the device body being caused to ascend and descend vertically; and a deployable weight integral with said device body, wherein said deployable weight is selectably moveable from a first position between the bow and stern of the device body to a second position in which the deployable weight is tethered to but outside of the profile of the device body in a manner which causes center of mass of the device body to move sufficiently aft to cause the device body to move from the horizontal orientation to a vertical orientation when in water. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of a combined autonomous underwater vehicle and buoy device built in accordance with the present disclosure in a horizontal orientation and its autonomous underwater vehicle configuration while in water. 
         FIG. 2  is a side elevational view of a combined autonomous underwater vehicle and buoy device built in accordance with the present disclosure in a vertical orientation and its buoy configuration while in water. 
         FIG. 3  is a top plan view of a combined autonomous underwater vehicle and buoy device built in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Described herein is a combined autonomous underwater vehicle and buoy device that operates to travel underwater in a horizontal orientation that defines an autonomous underwater vehicle configuration as an autonomous underwater vehicle to a desired location and then, once it reaches the desired location, move into a vertical orientation that defines a buoy configuration and operate as a buoy. Referring now to the drawings, and in particular,  FIGS. 1, 2 and 3 , Applicant&#39;s combined autonomous underwater vehicle and buoy device is shown having an elongated, modular device body  10  that operates as a hull and is thus sized, shaped and constructed to travel underwater. The device body  10  includes a proximal end which serves as a bow when the device body is in the horizontal orientation and a distal end which serves as a stern when the device body is in the horizontal orientation. Integral with the device body  10  is a ballast tank  11 , a plurality of fins  12  (in this case, a pair of fins), a rudder  13 , antennae  14 , a deployable weight  15 , and an internal control system (not shown). 
     The ballast tank  11  may be positioned adjacent or otherwise proximal to the bow of the device body  10  and may be configured to increase and decrease buoyancy of the device body  10 , thereby causing the device body to either ascend and descend vertically. The ballast tank  11  may include a piston to flood or evacuate its internal space with seawater, with a relatively full tank decreasing buoyancy (causing the device body  10  to descend in the water) and a relatively empty tank increasing buoyancy (causing the device body  10  to ascend in the water). 
     The combined buoy device when in its autonomous underwater vehicle configuration may operate as an underwater glider and utilize the ascent and descent of the device body  10  generated by the increases and decreases in buoyancy to generate propulsion in the water. In this regard, the fins  12  may operate to generate lift that moves the device body  10  horizontally as the device body  10  is caused to ascend and descend vertically. 
     The combined buoy device may utilize differences in temperature between the relatively warm surface waters and the relatively cold deeper waters of the ocean to enable propulsion through temperature driven gliding in the same manner as a Slocum thermal glider. Such temperature driven gliding may incorporate a precisely calibrated oil filled bladder (not shown) integral with the device body  10  which would change density in response to temperature changes. In this regard, the changes in temperature would operate to create the increases and decreases in buoyancy used by the fins  12  to generate propulsion in the water. 
     The rudder  13  is integral with the stern of the device body  10  and is operative to control yawing motion of the device body  10 . 
     The antennae  14  may be defined by one or a plurality of transducer integral with the device body  10 . The antennae  14  may extend from the bow of the device body  10 , as illustrated in  FIGS. 1, 2, and 3 . The antennae  14  may alternatively, however, be positioned inside the device body  10 . 
     The deployable weight  15  may be defined as a weighted member which is selectably moveable from a position inside or otherwise flush with the device body  10 , as shown in  FIG. 1 , to a position outside of but still tethered or otherwise connected to the device body  10 , as shown in  FIG. 2 . It is appreciated that the mass of the deployable weight  15  relative to the device body  10  (not including the deployable weight  15 ) is such that when the deployable weight  15  is moved to a position outside of but still tethered or otherwise connected to the device body  10  while the device body  10  and deployable weight are underwater, the center of mass  16  of the device body  10  will move sufficiently aft to cause the device body  10  to move from a horizontal orientation to a vertical orientation. When in the position outside of but still tethered or otherwise connected to the device body  10 , the deployable weight  15  serves as a counterweight that operates to maintain the device body  10  in a vertical orientation. 
     The device body  10  also may include an internal control system having a battery, a positioning system interface, communications interface that is connected to the antennae  14 , and a controller. It is contemplated that the battery is operative to supply electrical power to the controller, positioning system interface, and communications interface, that the positioning system interface may be defined by a global positioning system and the transceiver may be defined by a transceiver. The controller is electrically connected to the positioning system interface, the communications interface, and the rudder  13  and is operative to receive geolocation positioning data from the positioning system interface, communicate electrical signals with remote devices (including remote electronic devices) through the communications interface, and selectively cause the ballast tank  11  to release fluid, and control the positioning of the rudder  13 . The controller may further include or be able to access software containing instructions which allow it to determine based on data from the positioning system interface when the device body  10  has reached a target geolocation and, when it has reached the target geolocation, automatically cause the device body  10  to transition from the autonomous underwater vehicle configuration to the buoy configuration. 
     The device body  10 , while still underwater and generally after travelling to a target geolocation as an autonomous underwater vehicle, may transition from the autonomous underwater vehicle configuration to the buoy configuration by adjusting its center of mass  16  to cause the device body  10  to move to a vertical orientation. The center of mass  16  is moved aft by moving the deployable weight  15  to a position outside of but still tethered or otherwise connected to the device body  10  and by emptying the ballast tank  11  of fluid. Once the device body  10  is in the vertical orientation, it is appreciated that the antennae  14  may be raised above the surface of the water. 
     The tether which connects the deployable weight  15  to the device body  10  may enable the deployable weight  15  to function as a sea anchor or may be sufficiently long to allow the deployable weight  15  to extend to the sea floor and serve as an anchor 
     The deployable weight  15  may additionally include a sensor package so as to allow the combined buoy device to act as a gateway from seafloor sensors to operators onshore and become a spar buoy. 
     The combined buoy device may be powered by batteries and a propeller in addition or in the alternative to its operation in the same manner as a Slocum thermal glider. 
     The combined buoy device may additionally include a recovery system which enables the deployable weight  15  to be winched back to and into the device body  10 . It is contemplated that such a feature is important for the deployed sensor package and sea floor to surface gateway concept referenced above. 
     The combined buoy device may additionally include a solar array for recharging its battery (or batteries). 
     The controller may also be connected to the fins  12  and operative to control the positioning of the fins  12  to adjust the nature of the lift generated from the vertical ascent and descent of the device body  10 . 
     It is contemplated that the combined buoy device may additionally be configured to further adjust its buoyancy capability, by retaining fluid in the ballast tank  11  or otherwise, to cause the device body  10  to sink below the surface of a body of water when it moves to the vertical orientation. In such an implementation, the combined buoy device may await further commands, such as acoustical commands travelling underwater. Advantageously, the combined buoy device could then be used as a gateway node that gathers data from seafloor sensors that is transmitted once it surfaces. 
     It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated 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.