Release and capture of a fixed-wing aircraft

In one embodiment, a system includes an unmanned, multirotor helicopter and a fixed-wing aircraft. The multirotor helicopter may couple to the fixed-wing aircraft to support and hold the fixed-wing aircraft. The multirotor helicopter may then elevate the fixed-wing aircraft from a launch site to a release altitude. The multirotor helicopter may also accelerate the fixed-wing aircraft to a release speed and upon reaching the release speed, release the fixed-wing aircraft. The unmanned, multirotor helicopter may then return to the launch site.

TECHNICAL FIELD

This disclosure generally relates to aircraft logistics and, more specifically, to the release and capture of a fixed-wing aircraft.

BACKGROUND

Fixed-wing aircraft perform a number of commercial, military, and civilian tasks. Once airborne, fixed-wing aircraft are power efficient and effective at cruising for long distances. However, fixed-wing aircraft typically require sufficient runway space to accelerate for takeoff and decelerate for landing.

SUMMARY OF PARTICULAR EMBODIMENTS

In accordance with the present disclosure, disadvantages and problems associated with the release and capture of a fixed wing aircraft may be reduced or eliminated.

In one embodiment, a system includes an unmanned, multirotor helicopter and a fixed-wing aircraft. The multirotor helicopter may be configured to couple to the fixed-wing aircraft to support and hold the fixed-wing aircraft. The multirotor helicopter may then elevate the fixed-wing aircraft from a launch site to a release altitude. The multirotor helicopter may also accelerate the fixed-wing aircraft to a release speed and upon reaching the release speed, release the fixed-wing aircraft. The unmanned multirotor helicopter may then return to the launch site.

In an example embodiment, a method includes coupling an unmanned, multirotor helicopter to a fixed-wing aircraft. The method may further include elevating the fixed-wing aircraft from a launch site to a release altitude and accelerating the fixed-wing aircraft to a release speed. Upon reaching the release speed, the method may include releasing the fixed-wing aircraft from the unmanned, multirotor helicopter. The method may then include returning the multirotor helicopter to the launch site.

Technical advantages of certain embodiments may include allowing for the removal of extraneous equipment, such as landing gear, from a fixed-wing aircraft. By relying on a multirotor helicopter to release and capture the fixed-wing aircraft, the fixed-wing aircraft may be lighter and more fuel efficient, allowing for longer flight times and/or additional payload. Another advantage provided by the release and capture system may allow for a reduction in the area needed to launch and land the fixed-wing aircraft, thereby expanding the conditions and operations where the aircraft may be utilized (e.g., from helipads, small, uneven tracts of land, and buildings). Still other advantageous may include reducing the damage inflicted on fixed-wing aircraft committed by launcher devices and net retrieval systems.

DESCRIPTION OF EXAMPLE EMBODIMENTS

To facilitate a better understanding of the present disclosure, the following examples of certain embodiments are given. The following examples are not to be read to limit or define the scope of the disclosure. Embodiments of the present disclosure and its advantages are best understood by referring toFIGS. 1 through 4, where like numbers are used to indicate like and corresponding parts.

Unmanned, fixed-wing aircraft perform a number of commercial, military, and civilian tasks. For example, the military may utilize fixed-wing aircraft to perform long-range reconnaissance missions, while farmers may rely on autonomous aircraft to survey large tracts of land. These aircraft may fly autonomously or be remote controlled by a pilot. Once airborne, fixed-wing aircraft are power efficient and effective at cruising for long distances. However, fixed-wing aircraft require sufficient runway space to accelerate for takeoff and decelerate for landing.

A number of runway-independent techniques have attempted to overcome the issues presented by limited runway space. For example, a rail launcher may quickly propel an aircraft into the air while a net or other reception device may capture the aircraft as it returns. However, rail launchers are bulky and difficult to deploy. Furthermore, when returning at flight speed, the net system may damage the aircraft as the aircraft flies into the net at higher speeds.

To utilize the benefits of fixed-wing aircraft while operating with limited runway space, embodiments of the present disclosure utilize an unmanned, multirotor device, such as a helicopter, to lift the fixed-wing aircraft into sky, accelerate with the aircraft until reaching a release speed, at which point the multirotor helicopter may release the aircraft and return to the launch area. To capture the fixed-wing aircraft, the multirotor device may again climb to a cruising altitude of the aircraft, transition to the cruising speed of the aircraft, reconnect to the aircraft, decelerate to a hover, and descend to the launch site. In this manner, a fixed-wing aircraft may launch and land from any location, regardless of whether a runaway is available.

Using a multirotor helicopter to release and capture a fixed-wing aircraft provides a number of technical advantages not realized by current systems. Certain embodiments of the disclosure may allow for the removal of extraneous equipment, such as landing gear, from the fixed-wing aircraft. This may allow the aircraft to be lighter and more fuel efficient. Removing extraneous equipment may also allow for longer flight times or additional payload. Another advantage may be that certain embodiments allow for a reduction in the area needed to launch and land the fixed-wing aircraft, thereby expanding the conditions and operations where the aircraft may be utilized (e.g., from helipads, uneven tracts of land, and buildings). In addition, some embodiments may reduce the damage inflicted on fixed-wing aircraft committed by launcher devices and net retrieval systems.FIGS. 1-4provide additional details for the unmanned, multirotor release and capture system that may provide these and other advantages.

FIG. 1illustrates an example system100for the release of a fixed-wing aircraft130using an unmanned, multirotor device120. In the illustrated embodiment, multirotor device120is coupled to fixed-wing aircraft130on launch site110. Launch site110represents any suitable location that allows multirotor device120to takeoff and/or return with fixed-wing aircraft130. In some embodiments, launch site110may represent an area that cannot accommodate a runway. For example, launch site110may be a helipad on a ship, a rooftop of a building, uneven terrain, a heavily populated event, or any other location not suitable for aircraft that require runway space to accelerate for takeoff and decelerate when landing.

To deploy fixed-wing aircraft130, multirotor device120may lift and elevate fixed-wing aircraft130to follow combined launch path140. A number of factors may determine the elevation and direction of combined launch path140. These factors may include the flight path and mission of fixed-wing aircraft130, surrounding environmental conditions (e.g., nearby buildings, fences, etc.), regulations (e.g., Federal Aviation Regulations or local ordinances), wind and weather patterns, and design limitations of fixed-wing aircraft130and/or multirotor device120(e.g., battery capacity, wing span, etc.). Combined launch path140may also vary based on the capabilities of multirotor device120such as the rate of elevation and lifting capacity.

In an example embodiment, multirotor device120, coupled to fixed-wing aircraft130, may takeoff vertically from launch site110. Multirotor device120may climb to a release altitude of 1000 feet at a rate of 500 feet-per-minute (fpm). At the rate of elevation, this may take multirotor device120approximately two minutes.

In some embodiments, upon reaching the release altitude multirotor device120may transition to a forward direction according to release path150. In some embodiments, multirotor device120may elevate at an angle during combined launch path140in the direction of release path150. Multirotor device120may continue accelerating according to release path150until reaching a release speed.

Depending on the size and abilities of fixed-wing aircraft130, multirotor device120may accelerate to any suitable release speed that allows fixed-wing aircraft to maintain flight after being released. For example, fixed-wing aircraft130may dispense pesticides as an agricultural crop duster. This may require a slower release speed (e.g., 30-40 km/h) than when fixed-wing aircraft130is performing long distance reconnaissance missions and needs to cruise at faster speeds (e.g., 100-120 km/h).

In some embodiments, fixed-wing aircraft130may utilize its own propulsion system to enhance the acceleration of multirotor device120. This may decrease the time needed to accelerate to the release speed and may ensure that fixed-wing aircraft130is operating at sufficient speeds to maintain flight once released.

Upon reaching the release speed, multirotor device120may release fixed-wing aircraft130at release position160. In certain embodiments, multirotor device120may travel with fixed-wing aircraft130at the release speed but not release fixed-wing aircraft130until reaching a certain destination, such as a predetermined coordinate.

At release position160, multirotor device120may initiate the release mechanism to detach fix-winged aircraft130. In some embodiments, fixed-wing aircraft130may initiate the release mechanism instead of multirotor device120. In certain embodiments, multirotor device120and fixed-wing aircraft130may coordinate the release sequence to ensure both devices are prepared to work individually upon release.

Following the release of fixed-wing aircraft130(and any post-release maneuvers), multirotor device120may follow solo return path180and return to launch site110. Although the illustrated embodiment shows multirotor device120returning to launch site110, in some embodiments, multirotor device120may return to a different location. For example, in some embodiments, multiple fixed-wing aircraft130may need to be deployed. Multirotor device120may launch a first fixed-wing aircraft130from a first launch site110and follow solo return path180to a second, different launch site110to release a second fixed-wing aircraft130. In this manner, a single multirotor device120may launch multiple fixed wing aircraft from multiple locations.

After returning to launch site110, multirotor device120may idle and/or wait for a signal to capture returning fixed-wing aircraft130.FIG. 2illustrates an example system200for the capture of fixed-wing aircraft130using unmanned, multirotor device120.

Upon receiving a signal to capture fixed-wing aircraft130, multirotor device120may elevate from launch site110according to solo launch path210. In some embodiments, the signal to capture fixed-wing aircraft130may be manually sent from any remote location. In some embodiments, the capture signal may be sent from fixed-wing aircraft130. For instance, when fixed-wing aircraft130is within a predetermined range of multirotor device120(e.g., 1, 5, 10 km, etc.) fixed-wing aircraft130may communicate a capture signal to multirotor device120. Multirotor device120may then initiate the process of capturing fixed-wing aircraft130.

In addition to the launch path considerations described inFIG. 1, solo launch path210may be influenced by a number of additional factors such as the return distance and heading of fixed-wing aircraft130, battery life, and the capture mechanism utilized by multirotor device120. For example, fixed-wing aircraft130may be returning from a reconnaissance mission and may be 10 kilometers from launch site110. Multirotor device120may wait until fixed-wing aircraft is within 5 kilometers before initiating its capture sequence based on the available battery power, which may limit flight time.

In some embodiments, multirotor device120and fixed-wing aircraft130may each comprise a number of sensors and communication devices to coordinate flight paths and couple during flight. Multirotor device120and fixed-wing aircraft130may use any suitable number of sensors and/or communication devices including, but not limited to GPS processors, navigation and autopilot programming, communication equipment, and signal processors. Additionally, multirotor device120and/or fixed-wing aircraft130may utilize one or more laser sensors, magnets, and cameras for facilitating the mid-air capture process.

In an example embodiment, multirotor device120and fixed-wing aircraft130may coordinate capture sequence212. Any suitable information may be communicated between multirotor device120and fixed-wing aircraft130including but not limited to capture speeds, capture elevations, and capture vectors. A capture speed may indicate the speed that each device should travel during capture sequence212. The capture elevation may represent the elevation at which each device should travel at during capture sequence212. The capture vector may indicate a direction and/or magnitude of travel that each device is flying during capture sequence212.

The coordination of the capture process between multirotor device120and fixed-wing aircraft130may be modeled as a master/master, master/slave, or any other suitable communication architecture. For example, in some embodiments, fixed-wing aircraft130may act in a master/slave configuration with fixed-wing aircraft130directing multirotor device120. As an illustration, fixed-wing aircraft130may send out a capture signal to multirotor device120to capture fixed-wing aircraft130once fixed-wing aircraft130is within 10 km of multirotor device120. Fixed-wing aircraft130may transmit the flight plan for solo launch path210and capture path220. Fixed-wing aircraft130may also designate a launch site110for multirotor device120to return once multirotor device120and fixed-wing aircraft130are coupled.

In the illustrated embodiment, multirotor device120may coordinate a capture sequence212defining a specific speed and vector for multirotor device120and fixed-wing aircraft130to fly. Multirotor device120may travel along capture path220accelerating or decelerating to a capture speed as indicated by capture sequence212. For example, multirotor device120may fly at an elevation above fixed-wing aircraft130until both devices have synchronized vectors and speeds. Multirotor device120may then descend in elevation and connect with fixed-wing aircraft130using, for example, one or more laser sensors, magnetic couplers, hooks, and/or cameras.

Multirotor device120and fixed-wing aircraft130may utilize any suitable devices to facilitate the coupling and capture of multirotor device120to fixed-wing aircraft130. For example, in some embodiments, multirotor device120and fixed-wing aircraft may be specifically tailored to couple to one another (e.g., using male-female connectors). In some embodiments, multirotor device120may have a universal capture mechanism to capture fixed-wing aircraft130. For instance, multirotor device120may have adjustable grappling arms to latch onto the wings of fixed-wing aircraft130and/or to the fuselage of fixed-wing aircraft130. In this manner, multirotor device120may capture a range of fixed-wing aircraft130models having varying wing-spans, widths, and sizes.

Once multirotor device120captures fixed-wing aircraft130, multirotor device120may then decelerate the two devices and descend back to launch site110along combined return path230. In some embodiments, multirotor device120may capture fixed-wing aircraft130and decelerate along combined return path230until reaching a hover. Multirotor device120may then descend down onto launch site110. In some embodiments, fixed-wing aircraft130may utilize its propulsion system to aid in the deceleration process. In this manner, multirotor device120and fixed-wing aircraft130may both return to launch site110in a controlled and safe manner.

Modifications, additions, or omissions may be made to systems100and200without departing from the scope of the disclosure. In some embodiments, multirotor device120may be controlled by a pilot in a remotely located control area. In some embodiments, multirotor device120may operate autonomously to release and/or capture fixed-wing aircraft130. For example, multirotor device120may follow a preprogrammed combined launch path140and climb to a specific elevation at a specific rate of speed. Multirotor device120may then release fixed-wing aircraft130and return to launch site120according to an autopilot program.

As another example, to maximize the locations were fixed-wing aircraft130may operate, in certain embodiments fixed-wing aircraft130may include landing gear to utilize runways when available and rely on multirotor device120if runways are unavailable. This may be beneficial if fixed-wing aircraft130is launching from a first location having sufficient area for a runway but traveling to a second location that cannot support a runway (or vice versa). Thus, the second location may still rely on and utilize fixed-wing aircraft130based on the capture and release capabilities of multirotor device120.

FIGS. 3A through 3Cillustrate perspective views of an unmanned, multirotor device120according to certain embodiments.FIG. 3Ais an illustration of multirotor device120showing an example embodiment of propeller clusters310a-310d(collectively “propeller clusters310”). In the illustrated embodiment, multirotor device120has four sets of propeller clusters310a-310dfor flying and maneuvering. Each propeller cluster310may have one or more rotors312a-312c(collectively “rotors312”). In the illustrated embodiment, each propeller cluster310has three rotors312.

In some embodiments, propeller clusters310may be fixed-pitch blades that may each be independently controlled to control flight speed and direction. In some embodiments, propeller clusters310may have a variable-pitch to control the vertical acceleration and climb rates. Although illustrated with four propeller clusters310each having three rotors312, multirotor device120may have any suitable number of propeller clusters310and/or rotors312per cluster.

For example, multirotor device120may have four propeller clusters310with each propeller cluster having a single rotor. In some embodiments, multirotor device120may have additional propeller clusters310depending on the control requirements of multirotor device120.

Landing supports320aand320b(collectively “landing supports320”) may allow multirotor device120to land and/or takeoff from launch site110without requiring fixed-wing aircraft130to use landing gear. For example, landing supports320may be sufficiently long in length to support both multirotor device120and fixed-wing aircraft130when stationary on launch site110. In some embodiments, supports320are retractable and only deploy when multirotor device120lands on launch site110. When flying, multirotor device120may retract supports320to improve aerodynamics.

Coupling mechanism330represents any mechanism suitable for capturing and supporting fixed-wing aircraft130. As described inFIGS. 1 and 2, coupling mechanism allows multirotor device120to capture fixed-wing aircraft130midair and transport fixed-wing aircraft130to launch site110. In some embodiments, coupling mechanism330may include a number of hooks and latches to secure multirotor device120to fixed-wing aircraft130. In some embodiments, coupling mechanism330may include one or more laser sensors, magnets, and cameras to monitor the distance and coupling between multirotor device120and fixed-wing aircraft130.

FIG. 3Cillustrates a top view of multirotor device120coupled to fixed-wing aircraft130. In the illustrated embodiment, propeller clusters310are positioned in between each wing and the fuselage of fixed-wing aircraft130. For example, propeller cluster310aand310bare positioned in front of the wings and on either side of the fuselage of fixed-wing aircraft130. Propeller cluster310cand310dare behind the wings and on either side of the fuselage of fixed-wing aircraft130. Positioning propeller clusters310a-310cin areas away from fixed-wing aircraft130may improve flight efficiency and reliability by limiting downdraft interference when multirotor device120is coupled to fixed-wing aircraft130.

In addition to propeller clusters310, rotors312, landing supports320, and coupling mechanism330, multirotor device120may include any suitable power supply. For example, multirotor device120may be battery powered through a rechargeable and/or replaceable battery system.

Modifications, additions, or omissions may be made to systems300without departing from the scope of the disclosure. For example, some embodiments of multirotor device120may have a single rotor for flying to release and capture fixed-wing aircraft130.

A component of multirotor device120and/or fixed-wing aircraft130may include an interface, logic, memory, and other suitable elements. An interface receives input, sends output processes the input and/or output, and performs other suitable operations. An interface may comprise hardware and software. Logic performs the operation of the component. For example, logic executes instructions to generate output from input. Logic may include hardware, software and other logic. Logic may be encoded in one or more non-transitory, tangible media, such as a computer readable medium or any other suitable tangible medium, and may perform operations when executed by a computer. Certain logic, such as a processor, may manage the operation of a component. Examples of a processor include one or more computers, one or more microprocessors, one or more applications, and other logic.

At step420, multirotor device120may elevate fixed-wing aircraft130from launch site110to a release altitude. In some embodiments, multirotor device120initiates the elevation process upon receiving a release signal from fixed-wing aircraft130to deploy fixed-wing aircraft130. Upon receiving the release signal, multirotor device120may follow combined launch path140. At step430, multirotor device120accelerates fixed-wing aircraft130to a release speed. Multirotor device120may accelerate along release path150while also climbing to a predetermined release altitude (e.g., 1000 ft.). In some embodiments, fixed-wing aircraft assists in the acceleration to release speed by utilizing its own propulsion system.

At step440, multirotor device120releases fixed-wing aircraft130upon reaching the release speed. In some embodiments, multirotor device120and fixed-wing aircraft130may synchronize the release so that each device is operational to fly upon de-coupling. In some embodiments, multirotor device120may quickly adjust flight paths after releasing fixed-wing aircraft130to avoid interfering with the flight path of fixed-wing aircraft130. After releasing fixed-wing aircraft130, at step450, multirotor device120may return to the launch site110.

At step460, multirotor device120determines whether fixed-wing aircraft130is returning for capture. In some embodiments, if fixed-wing aircraft130has not yet returned, multirotor device120may idle and continue to monitor whether fixed-wing aircraft130is ready for capture. If multirotor device120determines that fixed-wing aircraft130is ready for capture, or if multirotor device120receives a capture signal from fixed-wing aircraft130or another source the sequence may proceed to step462.

At step462, multirotor device120elevates from launch site110to a capture altitude. At step464, multirotor device120may accelerate to a capture speed. In some embodiments, multirotor device120may coordinate the capture altitude and capture speed with fixed-wing aircraft130. At step470, multirotor device120may capture the fixed-wing aircraft130. Each device may facilitate the capture sequence212using one or more sensors and navigation/communication equipment. In some embodiments, the capture speed and altitude may be coordinated at a remote location.

At step480, multirotor device120may decelerate to a hover with captured fixed-wing aircraft130. This may allow multirotor device120and fixed-wing aircraft130to reduce speed in a controlled manner without damaging fixed-wing aircraft130. At step490, multirotor device120may descend with captured fixed-wing aircraft130to launch site110.

Various embodiments may perform some, all, or none of the steps described above. Furthermore, certain embodiments may perform these steps in a different order or in parallel. Moreover, one or more steps may be repeated. Any suitable component of system100may perform one or more steps of the method.