Abstract:
A pod for an unmanned aerial vehicle is provided that may be removed and re-attached to the vehicle. The pod comprises an outer shell, within which a variety of payloads may be carried. A first surface on the vehicle frame comprises a plurality of connects or electrical traces. The plurality of attachments are used to removably attach the pods to the first surface. Thus, a wide variety of payloads may be delivered using the same unmanned aerial vehicle, simply by removing and attaching different pods to a fixed vehicle core. These pods may be shaped so as to form part of the vehicle exterior, and when the pods are attached to the frame, they enhance the aerodynamics of the vehicle.

Description:
GOVERNMENT RIGHTS 
       [0001]    This invention was made with Government support under Prime Contract Number W56 HZV-05-C-0724 awarded by the United States Army. The Government may have certain rights in this invention. 
     
    
     FIELD 
       [0002]    The present invention relates generally to unmanned aerial vehicles. More particularly, the present invention relates to modular pods for use with an unmanned aerial vehicle. 
       BACKGROUND 
       [0003]    Unmanned aerial vehicles (“UAVs”) are remotely piloted or self-piloted aircraft that can carry cameras, sensors, communications equipment, or other payloads. A UAV is capable of controlled, sustained, level flight and is powered by either a jet or an engine. The UAVs may be remotely controlled or may fly autonomously based on pre-programmed flight plans or more complex dynamic automation systems. 
         [0004]    UAVs have become increasingly used for various applications where the use of manned flight vehicles is not appropriate or is not feasible. Such applications may include military situations, such as surveillance, reconnaissance, target acquisition, data acquisition, communications relay, decoy, harassment, or supply flights. These vehicles are also used in a growing number of civilian applications, such as firefighting when a human observer would be at risk, police observation of civil disturbances or crime scenes, reconnaissance support in natural disasters, and scientific research, such as collecting data from within a hurricane. 
         [0005]    Currently, a wide variety of UAV shapes, sizes, and configurations exist. Typically it is the payload of the aircraft that is the desired product, not the aircraft itself. A payload is what the aircraft is carrying. UAVs are the delivery system for a payload and are developed to fill a particular application and a set of requirements. As previously mentioned, there are numerous applications for which a UAV may be used. For each new application, a different type of payload may be used. Because different payloads may require different processing capabilities, or may comprise different sizes, a variation of the UAV typically must be developed for each type of payload, or a completely new aircraft typically must be designed. Designing a new aircraft or developing a variation of the current UAV in use is time-consuming and costly. 
       SUMMARY 
       [0006]    In accordance with the present invention, removable pods for an unmanned aerial vehicle are provided. The removable pods can accommodate and deliver a wide variety of payloads with little or no modification to the core vehicle itself. 
         [0007]    A first surface on the core frame of the vehicle comprises a plurality of attachments. These attachments could be electric or mechanical connects. The plurality of attachments are used to attach pods carrying various payloads. Locking mechanisms located on the vehicle&#39;s engine supports may also attach to the pods to maintain the pods in the proper position during flight. Once the pods are connected to the vehicle frame, the vehicle flies to its destination. 
         [0008]    After the unmanned aerial vehicle has completed the flight, the vehicle lands and the pods may be removed and unloaded. The same pods may later be re-attached to the frame. Alternatively, if new pods carrying various other payloads are desired for another operation, the new pods may be attached to the first surface of the frame. The pods may be shaped so that the leading edge of each pod enhances the aerodynamics of the vehicle while in flight. When the pods are attached to the frame, each pod forms part of the exterior surface of the vehicle and the aerodynamic shape of the pod aids in the operation of the vehicle during flight. 
         [0009]    Pods that may be removed and exchanged from a core ducted fan gives a UAV versatility. A wide variety of payloads may be delivered using the same UAV, simply by removing and attaching different pods to the same vehicle core. This allows for greater manufacturing simplicity, as only a single type of unmanned aerial vehicle need be constructed. Costs may be decreased as well, as the storage and maintenance of a plurality of different types of unmanned aerial vehicles is no longer necessary. 
         [0010]    This vehicle will provide intelligence on enemy activity without unduly risking the lives of human pilots or ground reconnaissance teams. For civilian use, the vehicle could be used by law enforcement for surveillance on SWAT operations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Various embodiments are described herein with reference to the following drawings. Certain aspects of the drawings are depicted in a simplified way for reason of clarity. Not all alternatives and options are shown in the drawings and, therefore, the invention is not limited in scope to the content of the drawings. In the drawings: 
           [0012]      FIG. 1  is a perspective view of a core vehicle ducted fan according to one embodiment of the invention; 
           [0013]      FIG. 2   a  is a perspective view of an exemplary avionics pod; 
           [0014]      FIG. 2   b  is a perspective view of an exemplary payload pod; 
           [0015]      FIG. 2   c  is a perspective view of an exemplary common fuel pod; 
           [0016]      FIG. 3  is a perspective view of four exemplary pods attached to each other having a shape in accordance with an exemplary embodiment; 
           [0017]      FIG. 4   a  is a perspective view of the ducted fan of  FIG. 1  with attached pods and landing feet attached; and 
           [0018]      FIG. 4   b  is a side view of the ducted fan of  FIG. 4   a.    
       
    
    
     DETAILED DESCRIPTION 
       [0019]      FIG. 1  depicts a perspective view of a ducted fan core  100  according to one embodiment of the present invention. Ducted fan core  100  is provided for use as an unmanned aerial vehicle. 
         [0020]    Ducted fan core  100  comprises a frame  110 , an engine  120 , a plurality of control vanes  130 , a fan  140 , a duct portion  150 , a plurality of bars  160 , a plurality of actuators  170  (shown in  FIG. 4   b ), a gearbox assembly (not shown), and a plurality of engine supports  190 . Engine  120  comprises an exhaust port  122 , a light  124 , and an antenna holder  126 . Frame  110  comprises a first surface  112 . Each of the plurality of engine supports  190  comprises a first end  172  and a second end  174 . 
         [0021]    Fan  140  is mounted within duct portion  150 . Duct portion  150  is attached to frame  110 , extending through frame  110  as shown in  FIG. 1 . Engine  120  may be attached to fan  140 . Second end  174  of each of the plurality of engine supports  190  is attached to first surface  112  of frame  110  and first end  172  of each of the plurality of engine supports  190  is attached to engine  120 . Each of the plurality of actuators  170  is attached to each of the plurality of control vanes  130 . Each of the plurality of control vanes  130  is attached to frame  110  with a bar of the plurality of bars  160 . Each of the plurality of control vanes is also attached to each of the plurality of actuators  170 . The gearbox assembly is attached to engine  120 . 
         [0022]    Frame  110  may be manufactured as part of duct portion  150 . Alternatively, frame  110  may be manufactured separately from duct portion  150  and may be attached to duct portion  150 . Frame  110  may be attached to duct portion  150  with a cement or glue. Alternatively, frame  110  may be attached to duct portion  150  mechanically. Frame  110  may be manufactured from metal. Alternatively, frame  110  may be manufactured from a durable plastic or other material. First surface  112  of frame  110  may be a substantially flat surface. First surface  112  may comprise both electric and mechanical connects. First surface  112  may be a printed circuit board (“PCB”) or may have embedded electrical traces. Ribbon or edge connectors or a printed circuit board edge may be used. Alternatively, first surface  112  may comprise a fuel line quick-disconnect fitting. The plurality of engine supports  190  may be affixed to first surface  112 . Frame  110  may comprise a plurality of indents  114 , as shown in  FIG. 1 . Second end  174  of an engine support may be inserted into an indent of the plurality of indents, affixing engine support  190  to frame  110 . Alternatively, frame  110  may not have any indents, and each engine support  190  may be affixed to first surface  112  of frame  110 . 
         [0023]    Engine  120  may be a turbine engine. Alternatively, engine  120  may be a number of other engine types. Engine  120  may be offset to one side of the frame center to allow for the vehicle center of gravity to be adjusted. In  FIG. 1 , for example, a portion  128  of engine  120  is offset to the right of the frame. Exhaust port  122  serves as an opening to allow exhaust fumes to exit the engine. Light  124  is preferably lit while the fan is in operation, and serves to alert other vehicles in the air as well as control centers of the location of the UAV. Although only one light  124  is shown, more lights, or other signaling devices, may be present on the vehicle. Additionally, the location of light  124  may be in a different location than that shown in  FIG. 1 . Light  124  may blink. Alternatively, light  124  may remain on throughout the vehicle&#39;s entire flight. The gearbox assembly may be mounted to engine  120 . 
         [0024]    The plurality of engine supports  190  serves to support engine  120  within frame  110 . A first end  172  of each engine support may be attached to engine  120 . Although four engine supports  190  are shown in  FIG. 1 , other numbers of engine supports may be used. Alternatively, second end  174  may be attached to a different part of frame  110 . 
         [0025]    Each bar of the plurality of bars  160  extends between the frame  110  and each of the control vanes  130 , and is attached to a control vane. The plurality of bars  160  may be mechanically attached to the control vanes. The plurality of bars  160  may be made from a metal or a durable plastic. The plurality of bars  160  serves to stabilize the plurality of control vanes  130 . The plurality of bars  160  may alternatively be part of the frame  110 . 
         [0026]    The UAV may be designed to be transported in a backpack. A modular lightweight load carrying equipment pack (“MOLLE”) is an army and marine corps backpack. The MOLLE pack is a fully integrated, modular load bearing system consisting of a load bearing vest with butt pack, main nick with sustainment pouches and sleeping bag compartment attached to an external frame. There is also a patrol pack, which can be used separately or combined with the main nick for added load carrying capability. MOLLE can be configured in several different variations to fit the load handling needs of the mission. The load-bearing vest is typically worn and holds pockets for magazines and hand grenades. Although ducted fan core  100  is preferably designed to fit within a MOLLE pack, ducted fan core  100  may fit into a number of other bags or backpacks. Ducted fan core  100  may be used in non-military applications, and might not be housed within a pack for those applications. 
         [0027]    The ducted fan core  100  may weigh approximately 6-8 lbs. However, ducted fan core  100  may weigh more or less than this value, depending on materials used and size. The UAV may operate at altitudes of 100 to 500 feet above ground level, and typically the UAV will fly between 10 and 500 feet above the ground. The UAV can provide forward and down-looking day or night video or still imagery. The UAV may operate in a variety of weather conditions including rain and moderate winds. The system requires minimal operator training. Portable ground stations may be used to guide the aircraft and receive images from the cameras. The ground station can be used to program a flight path for the UAV or control it manually. The aircraft can also be equipped with electro-optical cameras for daylight operations or infrared cameras for night missions. 
         [0028]    The UAV may run autonomously, executing simple missions such as a program or reconnaissance, or it may run under the control of a crew. The crew may comprise a pilot and sensor operators. The pilot may drive the aircraft using controls that transmit commands over a C-band line-of-sight data link, or a Ku-Band satellite link. The aircraft may receive orders via an L-3 Com satellite data link system. The pilots and other crew members use images and radar received from the aircraft to make decisions regarding control of the UAV. 
         [0029]      FIGS. 2   a - 2   c  illustrate exemplary pods  200  that may be attached to ducted fan core  100 . Each pod may comprise a leading edge  210 . A leading edge is a line connecting the forward-most points of the pod&#39;s profile; it is the front edge of the pod. When an aircraft moves forward, the leading edge is that part that first contacts the air. The leading edge may be perpendicular to the airflow, in which case it is called a straight wing. The leading edge may meet the airflow at an angle, in which case it is referred to as a swept wing. Leading edge  210  of pod  200  may be shaped to enhance the aerodynamic aspects of the UAV. For example, leading edge  210  may comprise a convex curve  212 . When pod  200  is attached to frame  110  and the unmanned aerial vehicle is flying, air will hit leading edge  210  and flow in a desired direction so as to enhance the airspeed of the vehicle and minimize the obstruction of air hitting the vehicle. In addition, the shape of each pod  200  may be such that when the pods are affixed to frame  110 , the pods form an exterior portion of the UAV. A portion of the pod may comprise an indent (not shown) on the internal surface of outer shell  214  near the pod base so that when the pod base is attached to first surface  112 , the indented portion of the pod sits against duct portion  150  and the non-indented portion of the internal surface is flush with duct portion  150 . This allows for pod  200  to be integral with duct portion  150 . Air may flow over both the external surface of outer shell  214  and the internal surface of outer shell  214 . The internal surface of outer shell  214  may be shaped so that as air hits the leading edge, the air flows down and is guided along the internal surface to then impact fan  140 . 
         [0030]    Each pod  200  is a module. A module is a self-contained component of a system, which has a well-defined interface to the other components. Pods  200  can be interchanged as units without disassembly of the pod itself Pod  200  may comprise an outer shell  214  and an interior (not shown). The interior of each pod  200  functions as a container, and contains a payload. The payload, or carrying capacity, of each pod may vary. In an unmanned aerial vehicle, the payload may carry equipment or instruments, for example. More specifically, for example, pod  200  may contain cameras, fuel, gas, or electronics. A variety of pods may be used with a UAV.  FIG. 2   a  illustrates a perspective view of an avionics pod  220 . Avionics pod  220  may be used to carry avionics equipment, such as cameras, a laser designer, a range finder, or supplies. Avionics pod  220  may comprise an extension  222  to accommodate mission specific electronics. Payload pod  230  may be used to carry integrated flight management for the purpose of an application designed for the pod, i.e. surveillance. Common fuel pod  240  may be used to carry fuel. Pod  200  may carry payloads comprising cameras for the purpose of taking photographs or to videotape the ground below the vehicle&#39;s flight path. 
         [0031]    Pod  200  is not necessarily limited for use with an unmanned aerial vehicle. Pod  200  may also be used with a terrestrial vehicle. For example, after pod  200  is detached and removed from the UAV, pod  200  may be attached to a terrestrial vehicle before arriving at the desired destination. Pod  200  may be attached to the terrestrial vehicle using the same attachment mechanisms as used for attachment to a UAV. 
         [0032]    Four attached pods having a shape in accordance with an exemplary embodiment may be described by reference to  FIG. 3 . Although  FIG. 3  shows four pods attached to each other, when attached to a UAV the pods may instead be attached to engine supports  190 , as shown in  FIG. 4 . When attached as shown in  FIG. 3 , pods  300  form a circumference. As depicted in  FIG. 3 , each pod  300  has a lip  302 . Lip  302  comprises an internal lip portion  304  and an external lip portion  306 . A cross-section of a pod may be taken at the line depicted by  1 - 1 , which is a cross-section at a wide portion of pod  300 . A cross-section could also be taken at the line depicted by  2 - 2 , which is a cross-section at a narrow portion of the pod. Alternatively, a cross-section could be taken at any other point along the circumference of the attached pods. 
         [0033]    Each pod cross-section includes a lip highlight location  308  and a location  310  of maximum radial distance. Lip highlight location  308  is the forward-most point on lip  302  in the axial direction. The axial height of lip highlight location  308  may vary for a plurality of cross-sections. The location  310  of maximum radial distance is the point of maximum radial thickness in the cross-section. The radial distance of the location  310  of maximum distance may vary for a plurality of cross-sections. When the pods are designed so that when assembled together as shown in  FIG. 3 , there are four wide cross-sections separated approximately 90 degrees from each other along the circumference and narrow cross-sections between the wide cross-sections. This design may be referred to as the claw-shaped design, as shown in  FIG. 3 . However, the pods are not limited to the claw-shaped design, and a number of other pod designs may be used. As an example, the pods may be uniform in height, comprising a raised shape design. The shape of the pods may depend on the payload required, and may vary in order to suit the payload in use. In the claw-shaped design, each pod has a peak such that the assembly of four pods has a plurality of peaks  320 ,  322 ,  324 ,  326  and a corresponding plurality of troughs  321 ,  323 ,  325 ,  327 . Specific values associated with each cross-section and location may be varied in accordance with desired pod size, desired aerodynamic characteristics, and other design parameters. Additionally, the number of peaks and troughs may vary depending on design parameters and desired air flow characteristics. In a preferred embodiment, the axial height of highlight  308  may be biased toward the troughs in order to reduce blockage of flow by the peaks in forward flight. 
         [0034]    Adjusting the design of peaks  320 ,  322 ,  324 ,  326  and troughs  321 ,  323 ,  325 ,  327  may be useful for adjusting the center of gravity of a ducted fan UAV. The center of gravity, as well as the control authority, need to be maintained on a UAV. Pods  300  are arranged and designed to maintain both the center of gravity and the control authority. Control vanes  130  need control authority in order to properly direct the vehicle and maintain an upright position during flight. 
         [0035]    The internal lip portion  304  is the portion of the lip that extends from lip highlight location  308  to the location  312  where pod  300  is attached to the duct. The shape of the internal lip portion  304  is defined by the curve between locations  308  and  312 . When pod  300  is attached to the core UAV, location  312  is preferably flush with the duct wall, so that internal lip portion  304  becomes integral with the duct wall. Internal lip portion  304  may be inset to accommodate the wall of duct portion  150 . 
         [0036]    The external lip portion  306  extends from the lip highlight location  308  to the location  310  of maximum radial thickness. The shape of the external lip portion  306  is defined by the curve between locations  308  and  310 . 
         [0037]      FIG. 4   a  is a perspective view of the ducted fan core of  FIG. 1  in the operating position.  FIG. 4   b  shows a side view of the ducted fan core of  FIG. 4   a . In  FIG. 4   a , pods  200  are attached to first surface  112  of frame  110 . In addition to the attachment of the pods to first surface  112 , engine supports  190  may provide further attachment support. For example, each of engine supports  190  may comprise a butterfly lock  191  that slides into corresponding grooves on each pod and latches to lock each pod into place during flight. Alternatively, pins or a variety of other support or locking mechanisms may be used. Additionally, landing feet  192  have been attached to the plurality of engine supports  190 . Landing feet  192  serve to raise the UAV from the ground, enabling control vanes  130  to move so that the vehicle may be prepared for take off. Landing feet  192  also serve to land the vehicle once the vehicle has reached its final destination, protecting the parts that make up the core of the vehicle. Landing feet  192  may be removably attached to plurality of engine supports  190 . Alternatively, landing feet  192  may be attached to another part of ducted fan core  100 . 
         [0038]    An antenna  128  may lie within antenna holder  126 , and may allow the UAV to receive and transmit signals. Unmanned aerial vehicle may be remotely controlled, or may be self-controlled for a particular journey. Once the vehicle has launched, control vanes  130  receive signals to control the direction of flight. Control vanes  130  move in response to the signals, altering the course of airflow from fan  140 , which guides the direction of flight for the vehicle. As the UAV flies, air contacts leading edge  210  of pods  200 , flowing around the surface of each pod. Once the vehicle has reached its final destination (e.g. returned to base), landing feet  192  contact the ground. The pods  200  may then be removed and the payloads may be unloaded. The pods that were removed may then be re-attached to first surface  112  of frame  110 . Alternatively, new pods may be attached to first surface  112  of frame  110 .