Abstract:
A payload quick release mechanism for an unmanned aerial vehicle is provided. This mechanism is affixed to a structure on the unmanned aerial vehicle, and allows for quick attachment and removal of a payload from the unmanned aerial vehicle. The attachment device includes a body with a perimeter and a plurality of arms that extend from the body perimeter. Each arm includes an indented section, within which a tab extending from the payload top may be placed. When the payload tab rests within the indented section, the payload is prevented from translation and is attached to the mechanism.

Description:
GOVERNMENT RIGHTS 
     The United States Government has acquired certain rights in this invention pursuant to Contract Number W56 HZV-05-C-0724, awarded by the U.S. Army Tank Automotive and Armaments Command. 
    
    
     FIELD 
     The present invention relates generally to aerial vehicles. More particularly, the present invention relates to a mechanism with a quick release to attach and remove a payload from a ducted fan unmanned aerial vehicle. 
     BACKGROUND 
     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 flight and is often powered by either a gas turbine or a reciprocating internal combustion engine. The UAVs may be remotely controlled or may fly autonomously based on pre-programmed flight plans or more complex dynamic automation systems. 
     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. 
     As previously mentioned, UAVs often carry payloads. UAVs are the delivery system for a payload. Currently, payloads are typically held on to a UAV with bolt/washer/locknut assemblies. These assemblies make it difficult to remove and replace the payload, especially at night when visibility is poor. Handling the bolts, washers, and locknuts demands dexterity, and often, even a skilled assembler drops parts, loses them, or otherwise experiences difficulty. The result is increased time to assemble a payload to a UAV and inconsistent assembly quality. In combat or other adverse situations, increased time to assemble a payload to a UAV can prove harmful for the assembler. 
     SUMMARY 
     In accordance with the present invention, a payload quick release mechanism for an aerial vehicle is provided. This mechanism improves the ability to quickly attach and remove a payload from an aerial vehicle. 
     In one embodiment, an attachment device is provided. The attachment device comprises a body with a perimeter and a plurality of arms that extend from the body perimeter. Each arm comprises a first section extending from the body perimeter and a second section that extends at a non-zero angle from the first section. 
     In another embodiment, a method for attaching a payload to an unmanned aerial vehicle comprises affixing an attachment mechanism to the unmanned aerial vehicle, pressing a payload against the attachment mechanism, rotating the payload while maintaining pressure against the attachment mechanism, until a payload tab on the payload slides over an arm of the attachment mechanism and into an indented portion in the arm, and finally locking the payload tab into a position within the indented portion of the arm of the attachment mechanism. 
     In a third embodiment, a bayonet style quick release mechanism is provided. The mechanism comprises a body that is affixed to an unmanned aerial vehicle. The body comprises a plurality of arm members. Each arm member has a proximate end that is affixed to the body and a distal end. Each of the plurality of arm members comprises a section sized to receive a payload tab, and a lip at the distal end that is raised above the section. The payload tab extends from the top surface of a payload. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a perspective view of a payload quick release mechanism according to one embodiment of the invention; 
         FIG. 2  is an enlarged view of the arm of the payload quick release mechanism of  FIG. 1 ; 
         FIG. 3  is a perspective view of a payload quick release mechanism with a radial centering feature; 
         FIGS. 4   a  and  4   b  illustrate the payload quick release mechanism of  FIG. 1  on an unmanned aerial vehicle payload; and 
         FIG. 5  is an enlarged top view of the structure of  FIG. 4   b  with payload attached using the payload quick release mechanism. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  depicts a perspective view of a payload quick release mechanism according to one embodiment of the invention. 
     The payload quick release mechanism  100  includes a body  110  and a plurality of arms  120 . Body  110  comprises a perimeter  112 . Although a circular perimeter is shown in  FIG. 1 , perimeter  112  is not limited to a circular shape and various other shapes may be contemplated. Body  110  may be shaped to fit to an aerial system such as an unmanned aerial vehicle (UAV) structure, or a payload present on the UAV. The UAV may be a ducted fan UAV. In the alternative, the UAV may not comprise a ducted fan. Body  110  may comprise a plurality of attachment holes  114  and a plurality of cutouts  116 . Attachment holes  114  may be present to affix payload quick release mechanism  100  to a UAV structure on the UAV with attachment devices such as screws. Cutouts  116  may be present to decrease the weight of body  110 , or for access to the structure to which payload quick release mechanism  100  is attached. 
     Each of the plurality of arms  120  comprises a proximate end  121  and a distal end  123 . Proximate end  121  may be attached to perimeter  112 . In this embodiment, each arm would extend from perimeter  112 . In an alternative embodiment, each arm may be formed near the center of body  110  instead of the perimeter  112 , to accommodate a payload with a smaller perimeter than the quick release mechanism. Each of the plurality of arms  120  may be manufactured separate from body  110 , and may be attached to body  110  prior to use. In the alternative, each of the plurality of arms  120  may be manufactured as part of body  110 . Each arm of the plurality of arms  120  comprises a first section  122  and a second section  124 . First section  122  may extend substantially orthogonally from body perimeter  112 . Second section  124  may extend at a non-zero angle from first section  122 . 
     Payload quick release mechanism  100  may be made from a plastic or a composite material and may be molded into shape. In the alternative, payload quick release mechanism  100  may be machined using a variety of plastic or metal materials. As another alternative, payload quick release mechanism  100  may be made from a formed metal. Once the basic shape of payload quick release mechanism  100  is manufactured, any finishing cutouts  116  or attachment holes  114  may be machined into the part. 
       FIG. 2  illustrates an enlarged view of second section  124  of the payload quick release mechanism  100  of  FIG. 1 . Second section  124  may comprise a bayonet-style locking feature. The second section  124  may comprise a first portion  130  on a first plane, a second portion  132  on a second plane, a third portion  134  that extends between the first plane and the second plane, a fourth portion  136  on a third plane, and a fifth portion  138  that extends between the second plane and the third plane. The second plane may be substantially parallel to the first plane. In an alternative embodiment, the second plane may not be parallel to the first plane. The third plane may not be parallel to either the first plane or the second plane. Fourth portion  136  comprises a top surface  137 . 
     In another embodiment, the locking feature may comprise an arm that comprises an indent and a lip, wherein the indent is second portion  132  and the lip is fourth portion  136  as shown in  FIG. 2 . The entirety of the lip may not lie on the third plane, but may instead be slanted at an angle such that part of the lip or fourth portion  136  dips below the third plane. The arm  120 , or any portion thereof, may be manufactured from a material that has a natural resiliency, thus the arm  120 , or any portion thereof, has the ability not only to give way and move under exerted pressure, but to return to its original position after the pressure exerted is removed. The indent may be sized to receive a payload tab. The indent is preferably sized to provide a snug fit on either side of the payload tab, and not allow for the payload tab to translate. 
       FIG. 3  is a perspective view of a payload quick release mechanism  200  with a radial centering feature  210 . Radial centering feature  210  may be a stepped ring, as shown. Radial centering feature  210  aides in the proper alignment of a payload with payload quick release mechanism  100 . This is accomplished by providing radial alignment between the two pieces. Radial centering feature  210  may be manufactured as part of payload quick release mechanism  200  or as a separate piece. 
       FIG. 4   a  is an exemplary embodiment of a payload quick release mechanism on a UAV  300 , and  FIG. 4   b  is an enlarged view of the structure with the payload attached from  FIG. 4   a . UAV  300  may comprise a payload  310 , a structure  320  to which the payload attaches, an air duct  330 , engine cylinders  350 , control vanes  360 , landing gear  370 , and a payload quick release mechanism  380 . Structure  320  may be a pod, as shown in  FIG. 4   b . However, structure  320  is not limited to a pod, and may be another structure on the aerial vehicle. Payload  310  comprises a plurality of payload tabs  312 , as shown in  FIG. 5 , in a top view of the payload and pod configuration of  FIG. 4B . Payload tabs  312  may extend substantially orthogonally from the top surface of payload  310 . Payload quick release mechanism  380  is designed to have a sliding fit against payload tabs  312 , as shown in  FIG. 5  when payload  310  is affixed to structure  320  via payload quick release mechanism  380 . 
     In operation, payload quick release mechanism  380  is affixed to structure  320 . Payload quick release mechanism  380  may be affixed to structure  320  by inserting screws, rivets, or other attachment mechanisms through attachment holes  114  and actuating the attachment mechanism. Payload  310  is then pressed against payload quick release mechanism  380  and is rotated. When payload  310  is rotated, each of the plurality of payload tabs  312  applies pressure to top surface  137  of fourth portion  136 , depressing arms  120 . The payload tab  312  slides over the depressed fourth portion  136  and continues to move toward second portion  132  as the payload continues to rotate. The natural resiliency of arms  120  causes fourth portion  136  to snap up and return to the non-depressed position once payload tab  312  is no longer applying pressure to top surface  137 . Payload tab  312  rocks into place within the boundaries of second portion  132 , the fourth portion  136  stopping payload tab  312 , and the payload itself, from further rotation. Payload tab then rests within second portion  132 , and is effectively retained within second portion  132 . Portion  138  and portion  134  of each arm prohibits rotational movement and ensures the proper clocking of payload  310  with respect to the structure  320 , holding payload  310  to UAV  300  in the axial direction. To disassemble or remove payload from the payload quick release mechanism, a user may depress fourth portion  136  to overcome the spring force of arm  120 . Payload tab  312  may then be slidingly removed from its position on second portion  132  by rotating the payload in the opposite direction from which it was inserted, effectively reversing the locking turn. That is, fourth portion  136  is depressed to permit removal of the payload from payload quick release mechanism. 
     This system and method for the assembly and removal of a payload is a simpler procedure than ones in which a user must attach the payload with screws, washers, and locknuts. The risk of losing a part in either the assembly or removal process is mitigated. In addition, the processes afforded by the mechanism for attachment and removal of a payload are quicker to implement than traditional assembly and removal methods, saving a user time. 
     It should be understood that the illustrated embodiments are examples only and should not be taken as limiting the scope of the present invention. The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.