Abstract:
In one possible embodiment, a UAV payload module retraction mechanism is provided including a payload pivotally attached to a housing. A biasing member is mounted to bias the payload out of the housing and a winch is attached to the payload. An elongated flexible drawing member is coupled between the housing and the winch, the elongated drawing flexible member being capable of being drawn by the winch to retract the payload within the housing.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 13/730,828, herein incorporated by reference in its entirety, which is a continuation of PCT Application number PCT/US2011/042376, by Zwaan et al., entitled UAV PAYLOAD MUDULE CAMERA ASSEMBLY AND RETRACTION MECHANISM, filed 29 Jun. 2011, herein incorporated by reference in its entirety, which claims the benefit of the following U.S. Provisional Applications, which are both herein incorporated by reference in their entireties: 
         [0002]    U.S. Provisional Application No. 61/359,817 filed on 29 Jun. 2010, by Belik, et al., entitled UAV PAYLOAD MODULE CAMERA ASSEMBLY AND RETRACTION MECHANISM; and 
         [0003]    U.S. Provisional Application No. 61/359,809 filed on 29 Jun. 2010, by Belik, et al., entitled UAV HAVING HERMETICALLY SEALED MODULARIZED COMPARTMENTS AND FLUID DRAIN PORTS. 
     
    
     BACKGROUND 
       [0004]    Reducing weight and size are paramount in the design of small unmanned vehicles. Small unmanned aerial vehicles or UAVs typically are designed to be launched from, and land on dry land. Such vehicles are now being sought that can operate while being exposed to, or after being exposed to aquatic environments. For example, it may be preferred to land an unmanned aerial vehicle on water, rather than on land, either to lessen the impact of landing, or because it is more easily retrievable location. Typically, amphibious aircraft, both manned and unmanned, are able to take off and land in water. 
         [0005]    Hand launched amphibious UAVs though are not required to take off from the water, but are required to land on dry land, or on water. Some hand launced UAVs are designed to land by skidding along, or impacting the ground, which is considerably more abrupt than water landings. 
         [0006]    What is needed is an amphibious UAV that can withstand high impact ground landings. 
       SUMMARY 
       [0007]    In one possible embodiment, a UAV payload module retraction mechanism is provided including a payload pivotally attached to a housing. A biasing member is mounted to bias the payload out of the housing and a winch is attached to the payload. An elongated flexible drawing member is coupled between the housing and the winch, the elongated drawing flexible member being capable of being drawn by the winch to retract the payload within the housing. 
         [0008]    In various embodiments, the payload is pivotally attached to a forward position in the housing, such as by a hinge. In various embodiments, the hinge is located forward of the payload when the payload is in a stowed position. In some embodiments, the hinge may include a pivot shaft, with the biasing member including a spring disposed about the pivot shaft. In various embodiments, the biasing member urges the payload into a deployed position. 
         [0009]    In various embodiments, the payload includes a camera assembly which includes a camera and a pan tray, the pan tray being pivotally attached to the housing via a hinge, the pan tray having the winch and pan actuator. In some embodiments, the pan actuator is located between the hinge and the winch. 
         [0010]    In various embodiments, the elongated flexible drawing member may be a cable, belt, or other drawing means. 
         [0011]    In one possible embodiment, a UAV payload module retraction mechanism is provided having a payload module having a housing with an opening in a bottom wall of the housing. A payload is pivotally attached in a forward position within the housing. A biasing member is mounted to bias the payload out of the housing. A winch is mounted to the payload and a flexible cable is coupled between the housing and the winch for retracting the payload into and releasing the payload from the housing. 
         [0012]    In various embodiments, the payload may include a camera assembly situated to pivot out of the housing through the opening in the bottom wall. In some embodiments, the flexible cable is a belt. The biasing member may urge the payload to a deployed position and may include a spring. In various embodiments, the payload is pivotally attached to a forward wall of the housing via a hinge. In some embodiments, the hinge may include a pivot shaft, and the biasing member include a spring disposed about the pivot shaft. 
         [0013]    In various embodiments, the payload further includes a camera assembly having a pan tray mounted therewith, the pan tray being pivotally attached to the housing via a hinge, the pan tray including the winch and pan actuator, with pan actuator being located between the hinge and the winch. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The features and advantages of the present invention will be better understood with regard to the following description, appended claims, and accompanying drawings where: 
           [0015]      FIG. 1  shows a simplified perspective view of an amphibious unmanned aerial vehicle. 
           [0016]      FIG. 2  shows a simplified top view of the fuselage of the amphibious unmanned aerial vehicle of  FIG. 1 . 
           [0017]      FIG. 3  shows a simplified side view of the fuselage of an amphibious unmanned aerial vehicle of  FIG. 1 . 
           [0018]      FIG. 4  shows a simplified cut away side view of one embodiment of a payload module. 
           [0019]      FIG. 5  shows a simplified cut away side view of one embodiment of a payload module of  FIG. 4 , with the payload partially retracted into the housing. 
           [0020]      FIG. 6  shows a simplified cut away side view of one embodiment of a payload module of  FIG. 4 , with the payload fully retracted into the housing. 
           [0021]      FIG. 7  shows a simplified cut away top view of one embodiment of the pan tray of the camera assembly. 
       
    
    
     DESCRIPTION 
     Amphibious Unmanned Aerial Vehicle 
       [0022]      FIG. 1  shows a simplified perspective view of an amphibious unmanned aerial vehicle or UAV  10 . The UAV  10  has a fuselage  100  of the amphibious unmanned aerial vehicle  10  has modularized compartments  120 ,  130 , and  140  to contain modular components or modules, such as a battery module  20 , a payload module  30 , and avionics electronics module  40 . In various embodiments, the wings  15  and/or  16  may be constructed of multiple pieces, which may separate, and/or “break away” or separate from the fuselage  100  during landings. 
         [0023]      FIG. 2  shows a simplified top view of the fuselage  100  of the amphibious unmanned aerial vehicle  10  of  FIG. 1 . The walls  110  of the fuselage  100  are composed of a buoyant material so that the fuselage  100  will float without wings (not shown) attached when the fuselage is fully loaded with components, such as the battery  20 , the payload  30 , and the avionics electronics  40 , shown in  FIG. 1 , and other aircraft parts and components. For example, the walls  110  may have a molded foam core sealed with a waterproof skin, though this is not required. The walls  110  may be a single continuous wall or multiple wall sections, or the like. 
         [0024]    In this embodiment, the fuselage is separated into three compartments, a forward battery compartment  120 , a central payload compartment  130 , and a rear avionics compartment  140 . The forward battery compartment  120  is separated from the central payload compartment  130  by separator wall  150 . The central payload compartment  130  is separated from the rear avionics compartment  140  by separator wall  160 . In the embodiment shown, tabs  104 ,  105 , and  106  are employed as a means to secure the components (not shown) in the compartments  120 ,  130 , and  140 . The tab  105  may be rotated by hand using the pivotable handle  105   h  to allow installation of a battery (not shown) and then rotated back to the position shown to lock the battery in the forward battery compartment  120 . Other securing mechanisms may be used instead or in addition to the rotatable tabs  104 ,  105 , and  106 . 
         [0025]    The battery compartment  120  has mounting surfaces  122  which support a battery (not show). In this embodiment, a connector  124 , which may be a surface mount connector or the like, is generally flush with the mounting surfaces  122 . Channels  126   f  and  126   r  are recessed below the mounting surfaces  122 . Drainage openings such as weep holes  128   b  in the channel  126   f  extend through the bottom wall  110   b  of the fuselage  100 . Weep holes  128   s  (shown in  FIGS. 1-3 ) in the channel  126   r  extend through the side wall  110   s  of the fuselage  100 . 
         [0026]    The mating surface  124   m  of the connector  124  is located above the channels  126   f  and  126   r  so that the mating surface is not submerged in water when the battery  20  ( FIG. 1 ) is connected/disconnected, if the fuselage is out of the water. Wiring  123   f  and  123   b  may be routed in the channels  126   f  and  126   b , respectively, and recessed and/or embedded through the fuselage  100  to provide power to the motor (not show) and avionics electronics module  40  and/or a payload module  30 . 
         [0027]    The central payload compartment  130  has front and rear mounting surfaces  132   f  and  132   r  which support a payload, such as a camera assembly (not shown). The payload module  30  may contain the imaging, sensing, or other passive, active, non-lethal, or lethal payload devices. In this embodiment, a connector  134 , which may be a surface mount connector or the like, is generally flush with the mounting surface  132   r . The mounting surface  132   r  may form an enclosure  163  to contain the connector  134  and associated wiring. The enclosure may form a lower part of the separator wall  160 . Weep holes  228   s  (shown in  FIGS. 1-3 ) may extend from inside the enclosure  163  through the side wall  110   s  to allow water to exit the enclosure  163 . In this embodiment, the central compartment  130  has a large opening  131  in the bottom so that a camera can be utilized, such as by viewing downward or by lowering it into the airstream through the large opening  131 . The large opening  131  also allows drainage of fluid from the central compartment  130 . 
         [0028]    In various embodiments, the mating surface  134   m  of the connector  134  may be located high above the opening  131 , on the top of the enclosure  163 , so that the mating surface is not submerged in water when the payload  30  ( FIG. 1 ) is connected/disconnected, even if the fuselage is not completely out of the water. 
         [0029]    The rear avionics compartment  140  has a mounting surface  142  in a bottom of the avionics compartment  140 . The mounting surface  142  has a forward channel  146   f  and a rear channel  146   r . Channels  146   f  and  146   r  are recessed below the mounting surface  142 . Drainage openings such as weep hole  228   s  (shown in  FIGS. 1-3 ) in channel  146   f  extends through the side wall  110   s  of the fuselage  100 . Weep holes  228   b  (shown in  FIGS. 2 and 3 ) in the channel  146   r  extend through the bottom wall  110   b  of the fuselage  100 . A sloping recess  229  in the mounting surface  142  drains water off the mounting surface  142  and into the channel  146   r.    
         [0030]    The embodiment shown in  FIG. 3  has an opening  141  in the side wall  110   s  of fuselage  100 , to expose a heat sink  41  ( FIG. 1 ) and allow heat generated by the avionics electronics  40  ( FIG. 1 ) to be released. 
         [0031]      FIG. 3  shows a simplified side view of the fuselage  100  of an amphibious unmanned aerial vehicle  10  of  FIG. 1 . In this embodiment, optional skid pads  180  and  190  are secured to the bottom wall  110   b  of the fuselage  100 . The skid pads  180  and  190  are used in this embodiment for landing on hard surfaces. The skid pad  180  may be located directly below the forward compartment  120  and may be fabricated of a durable shock absorbing material of sufficient thickness and density to further protect from impact the component within the compartment  120 , such as the battery  20  ( FIG. 1 ). Similarly, the skid pad  190  may be located directly below the rear compartment  140 , and may be fabricated of a durable shock absorbing material of sufficient thickness and density to further protect from impact a component within the compartment  140 , such as the avionics electronics  40  ( FIG. 1 ). 
         [0032]    Weep holes  128   s  extend through the side wall  110   s  of the fuselage  100 . The weep hole  128   s  extends through the side wall  110   s  and into rear channel  126   r  of the battery compartment  120 . The weep hole  228   s  extends through the side wall  110   s  and into the enclosure  163  of the central payload compartment  130 . 
         [0033]    The fluid drainage openings may be weep holes, fluid drainage ports, or the like. 
         [0034]    Various embodiments provide a fuselage  100  for a UAV which can land both on water and rugged terrain. Instead of sealing the entire aircraft from water intrusion, various embodiments achieve the ability to land on water by having just the individual electrical and electronic components, i.e. battery, payload, avionics electronics, and associated connectors and wiring, hermetically sealed. 
         [0035]    This allows the rest of the aircraft to remain buoyant and any water in the aircraft draining by a set of fluid drain ports when the UAV is retrieved from the water. In this manner, the protection of the electrical and electronic components is not dependant on maintaining the integrity of the fuselage  100  or the exterior walls  110 , which is likely to be damaged during landings on hard and/or rugged surfaces (typical of land landings). 
         [0036]    This also allows the volume within the aircraft that needs to be waterproof to be minimized, thus reducing weight and overall system complexity. 
         [0037]    Further, the aircraft&#39;s ability to land on hard surfaces or rugged terrain without damage to the electrical and electronic components is achieved not just by having these components encased in modularized compartments  120 ,  130 , and  140 , but also by allowing the walls  110  of the compartments  120 ,  130 , and  140  to be partially compromised without necessarily causing failure of the UAV. The walls  110  create an impact zone around the electrical and electronic components within the compartments  120 ,  130 , and  140 , and the separators inhibit the components  20 ,  30 , and  40  from impacting each other. Optionally, in some embodiments, the walls  110  and mounts  122 ,  132   f ,  132   r , and  142  are such that the components  20 ,  30 , and  40  ( FIG. 1 ) are recessed from the walls  110  and/or their respective separators  150  and  160  ( FIG. 2 ). Additional shock absorbing material (not shown) may be added within the compartments  120 ,  130 , or  140  to further reduce any chance of damage to the components  20 ,  30 , or  40  from impacts. 
         [0038]    As illustrated in  FIGS. 1 and 2 , the fuselage  100  may contain an optional exterior channel  110   c  in the side  110   s  of the fuselage  100 , extending rearward from a hole  218  in the side wall  110   s  at the avionics compartment  140 , to the tail section of the aircraft  10 . Wiring  203  extends through the hole  218  and along the exterior channel  110   c  to connect the avionics component  40  to an actuator assembly  202  for actuating the control surfaces in the tail of the aircraft  10 . The exterior channel  110   c  allows the wiring to be easily accessed for inspection, repair, and replacement. 
       Retractable Camera Assembly 
     (FIGS.  4 - 7 ) 
       [0039]      FIG. 4  shows a simplified cut away side view of one embodiment of a payload module  30 . Referring to  FIGS. 1, 3 and 4-7 , a retraction mechanism  410  is provided for a payload  400  for moving the payload  400  from a stowed position (shown in  FIG. 6 ) within the UAV  10  to a position extended out of the payload module  30  as shown in  FIG. 4 , and thus from the bottom  110   b  of the fuselage  100  of the UAV  10 .  FIG. 5  shows a simplified cut away side view of one embodiment of a payload module  30  of  FIG. 4 , with the payload  400  partially retracted into the housing  35  and  FIG. 6  shows a simplified cut away side view of one embodiment of a payload module  30  of  FIG. 4 , with the payload fully retracted into the housing  35 . 
         [0040]    The payload  400  may be a gimbaled pan and tilt camera assembly  405  as shown, which, when in the extended position can view about and below the UAV  10 . During retraction or extension of the camera assembly  405 , the camera assembly  405  moves about a single pivot point/axis or hinge  420 . The camera assembly  405  moves as shown by the arrows  422   d  in the direction of deployment outside of the housing  35 , and  422   s  in the direction to stow the payload  400  within the housing  35 . In other embodiments, the hinge  420  may have multiple pivot points with multiple pivot axes (not shown). 
         [0041]    Generally, opposite of this hinge  420  on the camera assembly  405  is a winch  430 . The winch  430  is in turn connected by a cable  440  at, to, or with a wall  35   w  of the housing  35 , either directly or indirectly, such as with a fastener  450 , or other securing means to the forward wall  35   f , so that the camera assembly  405  can be fully retracted within the housing  35  of the module  30  by operation of the winch  430 . The winch  430  is located in the pan tray  415 . 
         [0042]    A biasing member, such as a spring  460 , at or about the hinge  420  is used to bias the payload  400  down to its extended position (shown in  FIG. 4 ). Stops, rests, or limiters (not shown) associated with the camera assembly  405  and/or the housing  35  may be utilized limit motion of the camera assembly in its extended position. In some embodiments, the cable  440  may by itself, or in addition to other limiters, limit the motion of the camera assembly  405  in its extended position and thus may be in tension when the camera is fully extended. Further, in some embodiments, the spring  460  provides enough force to keep the camera assembly  405  stable when extended into the airstream. In other embodiments, an actuatable locking mechanism (not shown), may be used secure the camera assembly when extended, if desired. 
         [0043]    The payload  400  may be situated in the UAV  10  so rotation of the camera assembly  405  about the hinge  420  into the housing occurs along the direction of the travel of the UAV  10 . In the event of a failure of the retraction mechanism  410 , this configuration allows the camera assembly  405  to retract back into the UAV  10  as it contacts the ground upon landing, thereby reducing the probability, or severity of damage to the payload  400 . To facilitate this, the hinge  420 , or other pivot means, is located forward and near the bottom of the housing  35 . Thus, the hinge  420  may be located on the forward wall  35   f  of the housing  35 , so that the axis of the hinge pivot shaft  795  ( FIG. 7 ) is orthogonal to the direction of motion of the UAV  10 . 
         [0044]    The use of the cable  440  further provides for robust operation and environmental survivability, as well as a reduction in weight. The term cable as referred to herein includes braided cable, ribbon cable, a belt, a strap, a rope, a chain, or other flexible means to support tension or strain. In one embodiment, the cable  440  may be a NYLON, KEVLAR, or other material belt that is reliable, lightweight, and not susceptible to corrosion. 
         [0045]    In the embodiment, the fastener  450  may also function as a stop or rest  450   r  for the camera assembly  405 . In this embodiment, the pan tray  415  seats against the rest  450   r  when the camera assembly is fully retracted as shown of  FIG. 6 . In other embodiments, the fastener  450  and the rest  450   r  may be separate mechanisms. 
         [0046]      FIG. 7  shows a simplified cut away top view of one embodiment of the pan tray  415  of the camera assembly  405 . The pan tray  415  houses the pan motor assembly  745 , which is used to pan the camera assembly  405 . The winch motor  735  is also housed within the pan tray  415  and is coupled via worm gears  755 , also housed in the pan tray  415 , to the winch drum  785 . The winch drum  785  is external to the pan tray  415  and is located opposite the pivot shaft  795 . 
         [0047]    In this embodiment, the bottom  35   b  of the housing  35  is not sealed so the payload module  30  has an open bottom  35   b  to facilitate deployment of the payload  400 . Thus, in this embodiment the pan tray  415 , as well as the tilt cylinder  425  are individually sealed. The tilt cylinder  725  typically houses the tilt motor assembly (not show) and the imaging, sensing, or other passive, active, non-lethal, or lethal payload devices  465  and  475 . 
         [0048]    It is worthy to note that any reference to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in an embodiment, if desired. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
         [0049]    The illustrations and examples provided herein are for explanatory purposes and are not intended to limit the scope of the appended claims. This disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the spirit and scope of the invention and/or claims of the embodiment illustrated. 
         [0050]    Those skilled in the art will make modifications to the invention for particular applications of the invention. 
         [0051]    The discussion included in this patent is intended to serve as a basic description. The reader should be aware that the specific discussion may not explicitly describe all embodiments possible and alternatives are implicit. Also, this discussion may not fully explain the generic nature of the invention and may not explicitly show how each feature or element can actually be representative or equivalent elements. Again, these are implicitly included in this disclosure. Where the invention is described in device-oriented terminology, each element of the device implicitly performs a function. It should also be understood that a variety of changes may be made without departing from the essence of the invention. Such changes are also implicitly included in the description. These changes still fall within the scope of this invention. 
         [0052]    Further, each of the various elements of the invention and claims may also be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of any apparatus embodiment, a method embodiment, or even merely a variation of any element of these. Particularly, it should be understood that as the disclosure relates to elements of the invention, the words for each element may be expressed by equivalent apparatus terms even if only the function or result is the same. Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled. It should be understood that all actions may be expressed as a means for taking that action or as an element which causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates. Such changes and alternative terms are to be understood to be explicitly included in the description. 
         [0053]    Having described this invention in connection with a number of embodiments, modification will now certainly suggest itself to those skilled in the art. The example embodiments herein are not intended to be limiting, various configurations and combinations of features are possible. As such, the invention is not limited to the disclosed embodiments, except as required by the appended claims.