FIELD OF INVENTION

This application relates to an unmanned aircraft system, and more particularly it relates to a modular payload lifting system for use with an unmanned aircraft system.

BACKGROUND

Blended wing body (BWB) aircraft have attempted to contain the payload within the confines of the airframe itself. BWB airframes are thin and do not offer the payload volume as found in a conventional main wing, fuselage and tail group aircraft construction. BWB constructions for small unmanned aircraft systems (UAS) with wingspans of less than 10 feet offer only a few inches of vertical payload space. Furthermore, the tolerance of center of gravity (CG) balance of BWB aircraft is much more critical than conventional aircraft designs. Therefore, manufacturers of BWB small UAS designs have little room for payload and that payload must be installed inside the airframe in such a manner that the aircraft balances within a fraction of an inch on its CG.

Attempts to build around those limitations by installing a cylindrical or rectangular fuselage in the center of the BWB aircraft increases payload volume and aids in properly balancing the aircraft on its CG. However, it is difficult to change out the payload so that the aircraft can perform multiple missions. BWB small UAS payload-centric aircraft are developed and constructed around a specific payload, making single purpose, mono-mission small UAS. Each small UAS today is developed around a payload and is able to perform only one specific task, forcing customers to purchase multiple models of the same airframe to perform multiple missions. Most small UAS operators desire the ability to use a single airframe and swap out payload pods in the field. However, this is not possible with present BWB designs because of the sensitivity of the aircraft center of gravity and the limited storage capacity. What is needed is an unmanned aircrafy system that is payload agnostic and provides a common airborne platform that is able to carry multiple payloads that can be easily changed in the field.

SUMMARY

The present invention solves the foregoing problems by providing a standard UAS platform that can be used as an intelligence, surveillance and reconnaissance platform one day and can perform nuclear, biologic and chemical detection missions the next.

The new common airframe allows payload manufacturers to develop payloads around a common UAS platform much like application developers develop "apps" for common smart phone platforms.

The present invention attaches payload pods to an airframe that has no landing gear and thus lands on the payload pod. A small UAS that is required to land on its belly endures a great deal of abuse and has to be built using robust, yet lightweight materials. The payload pod must protect the payload and must be strong enough to be used again and again after landing. The payload pod will be subjected to large G-forces when landing, as the payload pod will make contact with the uneven ground and obstacles.

One aspect of the invention is an unmanned aircraft system having an airframe, and a payload pod secured to the unmanned aircraft under the airframe.

A second aspect of the invention is a payload pod system including a nacelle attached atop an airframe of an unmanned aircraft system, and a payload pod secured to the unmanned aircraft system under the airframe. A third aspect of the invention is a payload pod including foam material having openings for receiving a payload, wherein the payload pod is adapted to be detachably secured to an airframe of an unmanned aircraft system.

An advantage of the invention is that it can be used in a wide range of applications because the payload pod can accommodate various payloads, such as sensors, cameras, etc, depending on the mission.

A feature of the invention is that the unmanned aircraft system using a blended wing body (BWB) aircraft does not require an onboard flight computer to remain stable in the air, and it is adapted for use with multiple payload and imaging applications.

The BWB aircraft can have a foam core to reduce damage, and it requires no runway and can be electric powered. The new vehicle offers the highest lift, greatest endurance and most rugged airframe for any unmanned airborne system in its size class.

Another feature of the invention is a field interchangeable wing system that allows the BWB aircraft to be modified depending on the job to be performed and the environmental conditions.

Another feature of the invention is that the BWB aircraft are person-portable, can be launched by one person, and are operated by using a hand-held control unit.

Another feature of the BWB aircraft are that it is electrically powered, configured to carry different payloads, electro-optical (EO), infrared (IR) and chemical sensors, and it provides remote sensing, precision mapping, and airborne scientific applications.

Another feature of the BWB aircraft is that it has a foam core that is resistant to damage and it can operate in locations lacking runways or cleared landing spaces

An advantage of the BWB aircraft is that it is payload-agnostic and damage-resistant. Another advantage of the invention is that it can accommodate multiple, interchangeable payloads on a single airframe.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.

Fig. 1 is a top view of an example of a BWB airframe;

Fig. 2 is a planar side view of payload pod and a nacelle;

Fig. 3 is a front view of an embodiment of an unmanned aircraft system;

Fig. 4 is a top exploded view of an embodiment of an unmanned aircraft system;

Fig. 5 is a side view of an airframe with wings detached;

Fig. 6 is a side view of an airframe with wings attached;

Fig. 7 is a perspective exploded view of an alternative embodiment of an unmanned aircraft system;

Fig. 8 is a perspective side view of an embodiment of an unmanned aircraft system;

Fig. 9 is a perspective bottom view of the unmanned aircraft system of Fig. 8;

Fig. 10 is a perspective side view of an alternative embodiment of an unmanned aircraft system;

Fig. 11 is a perspective side view of a vertical take off and landing unmanned aircraft system; and

Fig. 12 is a perspective front view of an alternative embodiment of a vertical take off and landing unmanned aircraft system. DETAILED DESCRIPTION

Referring to Fig. 1, there is shown an airframe 104 that includes first and second wing panels 106. The aiframe 104 can be a blended wing body (BWB) aircraft as shown in Fig. 1 or it can be vertical take off and landing aircraft (VTOL), e.g., Figs. 11 and 12 or a conventional aircraft with a fuselage and vertical and horizontal stabilizers, e.g., Fig. 7. The wing panels 106 can include a movable control surface 108 such as an aileron, which can be controlled by an electromechanical servo 110. A propulsion system 112 can be positioned at the rear of the airframe 104, and avionics 114, air-ground-air communications devices 116, and other electronic instrumentation can be housed in the airframe 104.

The BWB airframe 104 can have a main body and wings, which have generally rectangular plan forms. The wings can be detachable from sides of the main body for transporting the unmanned aircraft system (UAS) to launch and recovery sites. The wings can have wing tips that are generally flat and are generally parallel to the sides of the main body.

The main body can have mirror image leading edges and trailing edges. The wings can have leading edges and trailing edges in continuation of the leading and trailing edges of the main body. The leading edges of the main body and the leading edges of the wings are generally curved. The trailing edges of the main body and the trailing edges of the wings are generally sharp.

Inner attachments of the wings to the main body can be concealed within the airframe. For exampole, lugs can extend into complementary receivers with snaps or dislocations. The wing inner sides and the main body outer sides can be juxtaposed by pushing the wings inward and then back with respect to the main body. In flight and upon launch and especially upon landing, the wings sustain backward thrusts without changing their positions with respect to the main body.

One or more ailerons can be postioined in rear recesses on the wings and preferably help form the trailing edges of the wings. The ailerons can be moved by small servo motors. The airframe 104 can be launced into the wind by hand or with a small catapult, and can and without landing gear on its underside. As discussed in more detail below with regard to the paylod pod, cameras, instruments, and servo controllers can be mounted in recesses in the underside of the airframe 104. Fairings or transparent covers can maintain the aerodynamic surfaces of the airframe 104 and protect the equipment from damage upon landing.

An onboard microprocessor may receive and execute the pattern to be flown using an onboard GPS receiver to ensure coverage of the areas to be studied. Data from onboard cameras and sensors can be stored onboard for later downloading and can be continuously or periodically transmitted to a receiver at the launch and recovery site.

In an alternative embodiment, the aiframe 104 can have a body that is attachable to removable and replaceable wings at the sides of the main body. Outer tips of the wings can be generally flat and parallel to sides of the main body. The main body and wings can have matching lateral body surfaces and wing inner ends, which are flat and similarly shaped for smooth aerodynamic transitions. The wings can be easily detachable and re-attachable for moving the operational base and launch and landing zones, and for adjusting the UAS depending on the mission. For example, shorter wings can be used for higher speed operations than longer wings.

Leading edges of the main body and the leading edges of the wings can be smoothly rounded and curved with smaller upper radii and larger lower radii. Trailing edges of the main body and trailing edges of the wings can be thin and sharp. One main body can be interchangeable with pairs of wings to change characteristics of flight of the UAS. The wings and main body can be made of rugged resilient polymeric skin that can be filled with lightweight stereotactic foam. Equipment cavities in the bottom of the UAS aiframe 104 can be specially constructed for intended loads, for example of cameras and sensors. One or more ailerons can be positioned in outboard recesses in trailing edges of the wings. In one form the ailerons extend to the wing tips. Alternatively, the ailerons can erminate short of the wing tips.

An electric motor can drive a two-blade propeller with electric power stored in batteries in a battery housing. The motor and battery housing can be mounted on the center top of the main body for protection during no gear landings. Powering the motor is controlled by a remote control at the launch and landing site. Alternatively, an onboard computer can be programmed to turn off the motor prior to a landing glide to the preprogrammed landing site.

The body portion and the wings of the airframe 104 can have foam cores covered with a first cloth weave material, liquid adhesive, a second cloth weave and liquid adhesive laminations on the surfaces. The first and second cloth weave materials can have different directions of weave. The different directions of weave are oriented at about 45° with respect to each other. The foam core can be a polyurethane foam core, and the liquid adhesive can be a liquid urethane which soaks through the cloth weave material into the core. The cloth weave material and the liquid adhesive surround the upper surface, the leading edges and the lower surface of the airframe 104. Adding a strip of the cloth weave material and the liquid adhesive laminations over the leading edges of the BWB UAS strengthens the leading edges for field landings.

A payload pod 204 adapted for use with a BWB airframe 104 is shown in Fig. 2. The payload pod 204 can be a solid structure made from a foam material and can contain one or more machined openings 206 for receiving a desired payload, such as batteries and other avionics as required for the mission. The payload pod 206 can be attached to the airframe 104 using mechanical fasteners.

The payload pod 204 can have a curved frontal feature that allows for space for batteries and forward looking sensors. Furthermore, this frontal area can serve as a bumper from frontal impacts.

The lower section of the payload pod 204 can have a curved area that aerodynamically smoothes air flow to the rearward facing propulsion unit.

The front section of the payload pod 204 can have an interlocking channel that conforms to the nose of the airframe 104. The channel increases the impact tolerance of the modular payload lifting system and allows impact forces to be dissipated throughout the entire aircraft structure, which increases the impact G-forces the airframe 104 can endure and remain its flying status. The channel increases structural strength of the aiframe 104 sufficiently such that mechanical fastening systems, such as threaded inserts and machine screws, can be effective. Optionally but preferably a mechanical fastenign system 802 can include a nylon strap and a hook and loop fasteners.

The upper section of the payload pod 204 can have a curved area that provides smooth airflow over the top of the payload pod 204 and nacelle 202 attached atop the airframe 104. Nacelle 202 can provide protection from the environment and aerodynamic smoothing over the payload and avionics located within the BWB structure of the airframe 104 and payload pod 204. Nacelle 202 can be attached to the airframe 104 using mechanical fasteners 802.

Fig. 3-6 show a UAS 302 in which the payload pod 204 contains the payload, sensors, cameras, avionics and propulsion system and the wing panels 106 can be detached. As shown in Fig. 4, wing panels 106 contain movable control surfaces, elevons, and electro-mechanical servos to move these surfaces based on commands from the avionics on board the airframe 104. Payload pod 204 is a solid structure made from a foam material and contains openings 206 (see Fig. 5) adapted for receiving the payload, such as batteries and other avionics as required for the mission. The payload pod 204 can be attached to the wing panels 106 using wing tubes 404. The wing tubes 404 are the support structure used to connect the payload pod 204 to the wing panels 106, and, as such, the wing tubes 404 are the load bearing structure of the UAS 302.

Fig. 7 shows an alternative embodiment of a fixed- wing airframe 104. The airframe includes a main wing, tail boom, and horizontal and vertical stabilizers. The horizontal stabilizer and vertical stabilizer also can be referred to as the tail group. A payload pod 204 can be removable from the aircraft and can attach to a mounting plate to which the main wing and tail boom are attached. The propulsion system (not shown) can be mounted on the forward or aft end of the mounting plate.

The main wing can contain the movable control surfaces, i.e., ailerons and electromechanical servos, to move these surfaces based on commands from the avionics on board the airframe 104. The main wing can be mechanically joined to the mounting plate.

The tail boom can connect the tail group, consisting of the horizontal and vertical stabilizers, to the mounting plate, to which the main wing can be attached. The horizontal stabilizer provides pitch stability to the UAS 302 and contains the movable control surface, elevons, and electro-mechanical servos to move this surface based on commands from the avionics on board the airframe 104. The vertical stabilizer provides yaw stability to the UAS 302 and contains the movable control surface, rudder, and electro-mechanical servos to move this surface based on commands from the avionics on board the airframe 104.

The payload pod 204 can contain the payload, batteries and other avionics as required for the mission. The payload pod 204 can be attached to the mounting plate, which attaches the main wing, tail boom and payload pod. A propulsion system, can be be mounted on the forward or aft end of the mounting plate.

Fig. 8 shows a UAS 302 with a payload pod 204 and nacelle 202 attached to a BWB airframe 104. A mechanical fastening system 802 is used to secure the payload pod 204 and nacelle to the wing panel 106 of the airframe 104.

Fig. 9 shows the UAS of Fig. 8 from the bottom. The payload pod 204 is secured in place relative to the wing panel 106 of the airframe 104 by the mechanical fastening system 802.

Fig. 10 shows an alternative embodiment of a payload pod 204 and nacelle 202 secured to a BWB airframe 104. A mechanical fastening system 802 is used to secured the payload pod 204 and nacelle 202 in relation to the airframe 104.

Fig. 11 shows an alternative embodiment in which UAS 302 is a vertical take off and landing (VTOL) vehicle 1102 such as a helicopter. The payload pod 204 can be secured underneath the VTOL vehicle 1102.

Fig. 12 shows an alternative embodiment of a VTOL vehicle 1 102. The payload pod 204 can be secured underneath the VTOL vehicle 1102.

CONCLUSION

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the invention should not be limited by any of the above-described exemplary embodiments.