Ultra-quiet drone

Abstract

A drone with low acoustic characteristics is disclosed. The drone includes a fuselage, an inboard wing attached to the fuselage, a pylon located toward the aft end of the fuselage and having a higher end than the inboard wing, and a thruster connected to the pylon and located above the fuselage. The drone also includes multiple booms connected to the inboard wing and multiple horizontal stabilizers attached to the multiple booms. The horizontal stabilizers have an outboard stabilizer arrangement and are tiltable.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 356,885, filed June 29, 2022, which claims the benefit of U.S. Provisional Patent Application No. 18 / 181,067, filed March 9, 2023, which is incorporated by reference in its entirety.

[0002] The present disclosure relates generally to drones, and more particularly to noise-reduced drones. [Background technology]

[0003] Description of Related Art Conventional drones typically have propulsion fans with open rotors and propellers. These types of conventional drones have reached their acoustic limits. As a result, conventional drones are noisy. Summary of the Invention

[0004] A drone with reduced noise is described. In one embodiment, the drone includes a fuselage and an inboard wing attached to an upper surface of the fuselage. A pylon is attached toward the aft end of the fuselage, the pylon end extending higher than the inboard wing. A thruster configured to generate thrust is attached to the end of the pylon.

[0005] As a result, the thrusters are located at the drone's center of lift, providing sound insulation near the inboard wings. Noise emitted from the thrusters may be directed primarily outward, toward the fan plane of the thrusters. By placing the thrusters behind the trailing edge of the inboard wings, the inboard wings provide sound insulation near the wing tips, where payloads can be located more closely.

[0006] The drone further includes multiple booms attached to the wings near the fuselage. Multiple tails are attached to the ends of the booms. In one embodiment, the tails have an outward tail configuration to reduce wetted area and reduce drag and mass. The horizontal stabilizers are also rotatable, providing longitudinal stability during all phases of flight. [Brief explanation of the drawings]

[0007] [Figure 1A] 1 illustrates a front top left perspective view of a drone according to one embodiment. [Figure 1B] 1 illustrates a perspective view of a drone from the front, according to one embodiment. [Figure 1C] 1 illustrates a perspective view of a drone from the top left, according to one embodiment. [Figure 1D] 1 illustrates a perspective view of a drone from the top right according to one embodiment. [Figure 1E] 1 illustrates a perspective view of a drone from the top back according to one embodiment. [Figure 2] 1 illustrates an internal view of a drone fuselage according to one embodiment. [Figure 3A] 1 illustrates various views of a payload within a drone fuselage according to one embodiment. [Figure 3B] 1 illustrates various views of a payload within a drone fuselage according to one embodiment. [Figure 4] 1 illustrates an aileron and flaperon of a drone according to one embodiment. [Figure 5A] 1 illustrates a boom connection structure at the inboard wing tip of a drone according to one embodiment. [Figure 5B] 1 illustrates a boom connected to an inboard wing tip by a boom connection arrangement according to one embodiment. [Figure 6] 1 illustrates a tail connection surface at the end of a boom of a drone according to one embodiment. [Figure 7] 1 illustrates a movable control surface on a vertical stabilizer of a drone, according to one embodiment. [Figure 8] 1 illustrates a perspective view of a horizontal stabilizer of a drone according to one embodiment. [Figure 9] 1 illustrates a movable horizontal stabilizer for a drone according to one embodiment. [Figure 10] 1 illustrates a horizontal stabilizer rotation mechanism for a drone according to one embodiment. [Figure 11A] FIG. 1 illustrates a detailed view of the spline drive of the horizontal stabilizer rotation mechanism according to one embodiment. [Figure 11B] 1 illustrates a detailed view of the axis of a horizontal stabilizer of a drone, according to one embodiment. [Figure 11C] FIG. 1 illustrates a detailed view of a splined drive arm of a horizontal stabilizer rotation mechanism according to one embodiment. [Figure 12] 1 illustrates a process for connecting a horizontal stabilizer to a horizontal stabilizer rotation mechanism according to one embodiment. [Figure 13A] 10A-10C are detailed views illustrating the horizontal stabilizer in various rotational positions according to one embodiment. [Figure 13B] 10A-10C are detailed views illustrating the horizontal stabilizer in various rotational positions according to one embodiment. [Figure 14A] 1 illustrates multiple access covers in the boom for accessing the horizontal stabilizer rotation mechanism according to one embodiment. [Figure 14B] 1 illustrates a first portion of a horizontal stabilizer rotation mechanism accessible through a first access cover according to one embodiment. [Figure 14C] 10 illustrates a second portion of the horizontal stabilizer rotation mechanism accessible through a second access cover according to one embodiment. [Figure 15] 1 shows a perspective view of a drone according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The figures and the following description describe certain specific embodiments by way of example only. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods described herein may be used without departing from the principles described herein. Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings. It should be noted that wherever possible, like or similar reference numbers may be used in the drawings to indicate like or similar functionality.

[0009] First embodiment of drone structure 1A, 1B, 1C, 1D, and 1E illustrate various perspective views of a drone 100 according to one embodiment. Specifically, FIG. 1A illustrates a front, upper-left perspective view of the drone 100, FIG. 1B illustrates a front perspective view of the drone 100, FIG. 1C illustrates a top-left perspective view of the drone 100, FIG. 1D illustrates a top-right perspective view of the drone 100, and FIG. 1E illustrates a top-rear perspective view of the drone 100 according to one embodiment. In one embodiment, the drone 100 is a low-altitude Class II small unmanned aerial system (sUAS) configured for low-altitude, ultra-quiet command, control, communications, computers, intelligence, surveillance, and reconnaissance (C4ISR) missions. However, the drone 100 may be used for other applications.

[0010] In one embodiment, drone 100 (e.g., aircraft) includes fuselage 101, outboard wings 102, pylon 103, thrusters 109, multiple booms 105, multiple horizontal stabilizers 111 (e.g., wings), and multiple vertical stabilizers 107 (e.g., wings). Horizontal stabilizers 111 and vertical stabilizers 107 together form the tail of drone 100. Note that in other embodiments, drone 100 may include components other than those shown in FIGS. 1A-1E.

[0011] The fuselage 101 is the main body of the drone 100. The fuselage 101 is a hollow structure. The fuselage 101 may be a single continuous structure or may be a modular structure including multiple components that collectively form the fuselage 101. In one embodiment, the fuselage 101 contains one or more payloads. For example, the fuselage 101 contains a power supply unit 201, as shown in FIG. 2, which depicts an internal view of the fuselage 101. The power supply unit 201 includes one or more electric batteries (e.g., 22,000 mAh Li-Po batteries or advanced lithium-air batteries) for powering the drone 100. In one embodiment, the drone 100 is all-electric. However, in other embodiments, the drone 100 may utilize a hybrid electric system to enable longer endurance, more payload, and / or longer range.

[0012] In one embodiment, the fuselage 101 comprises an interior space 301 in the nose of the fuselage 101 that contains one or more payloads. The interior space 301 may be located in the forward (e.g., nose) portion of the fuselage 101, for example, as shown in Figures 3A and 3B. However, the interior space 301 may also be located in other portions of the fuselage 101.

[0013] An example of a payload located in the interior space 301 is a camera 303. The camera 303 faces forward, as shown in Figures 3A and 3B, and can capture content, such as images and / or video, while the drone 100 is in flight. A portion of the front of the fuselage 101 that defines the interior space 301 may be made of a transparent material, such as plastic or glass, to allow the camera 303 to capture content. Other examples of payloads that may be housed in the fuselage 101 include one or more sensors, such as radar, lidar, audio sensors, vibration sensors, other intelligence, surveillance, and reconnaissance (ISR) equipment, directional microphones, or some combination thereof.

[0014] In one embodiment, the fuselage 101 may further include electrical components for controlling the drone 100. Examples of electrical components for controlling the drone 101 include one or more controllers, such as one or more processors and memory device(s), used to control the thrusters 109 and actuate one or more control surfaces of the drone 100 (e.g., control of the ailerons, rudder, elevator, tabs, flaps, spoilers, slats, etc.).

[0015] In one embodiment, one or more landing mechanisms may be attached to the underside of the fuselage 101. The landing mechanisms may be landing gear (e.g., tricycle gear) or landing skids.

[0016] 1A-1E, the outboard wing 102 is attached to the upper surface of the fuselage 101, opposite the lower surface of the fuselage 101. The outboard wing 102 is a central element connecting the fuselage 101, the boom 105, the pylon 103, and the propulsors 109 together. The outboard wing 102 is located between a first end (e.g., forward) and a second end (e.g., aft) of the fuselage 101. The outboard wing 102 is configured to provide lift for flying the drone 100 and has a dihedral angle relative to the fuselage 101, which in one embodiment provides stability and an improved sensor field of view, as described in further detail below. The outboard wing 102 may be made of a composite material, such as carbon fiber, a metal (e.g., aluminum or titanium), or an alloy.

[0017] In one embodiment, the outboard wing 102 comprises a first side 102A disposed on a first side (e.g., right side) of the fuselage 101 and a second side 102B disposed on a second side (e.g., left side) of the fuselage 101. In one embodiment, the first side 102A and the second side 102B of the outboard wing 102 may be configured as a continuous structure connected to the upper surface of the fuselage 101. Alternatively, the first side 102A and the second side 102B of the outboard wing 102 may be separate structures each coupled to the upper surface of the fuselage 2101.

[0018] 1A-1E, the upper surface (e.g., top) of the inboard wing 102 is curved. The upper surface of the inboard wing 102 slopes downward from the leading edge of the inboard wing 102 to the trailing edge of the inboard wing 102. Referring to FIG. 4, the inboard wing 102 includes a number of control surfaces at the trailing edge of the inboard wing 102 for controlling the drone 100 during flight. In one embodiment, the control surfaces include a number of ailerons 113 and a number of flaperons 115.

[0019] In one embodiment, the first side 102A and the second side 102B of the outboard wing 102 each include one or more ailerons 113 located toward the end of the trailing edge of the outboard wing 102. Additionally, the trailing edges of the first side 102A and the second side 102B of the outboard wing 102 each include one or more flaperons 115. As shown in Figure 4, the flaperons 115 on each side of the outboard wing 102 are located between the corresponding aileron 113 and the fuselage 101. One end of each aileron 113 and flaperon 115 is configured to be attached to the trailing edge of the inboard wing 102. As shown in Figure 4, each aileron 113 and flaperon 115 is configured to pivot about an attachment point toward the trailing edge of the inboard wing 102 to control the movement of the drone 100 during flight. For example, the ailerons 113 are used to control the roll of the drone 100 (e.g., movement around the drone's longitudinal axis), which occurs during flight due to tilting of the lift vector, known as "rolling" or "banking." The flaperons 115 pivot and / or extend inward or outward from the trailing edge of the inboard wing 102 to control the lift and drag of the drone 100.

[0020] 5A , each end of the inboard main wing 102 includes a boom connection structure 501. The boom connection structure 501 is configured to attach a corresponding boom 105 to each end of the inboard main wing 102. The boom connection structure 501 is a plate-like structure including a connection surface 503 for connecting the boom to the inboard main wing 102. The connection surface 503 may have a first side 505 and a second side 507 opposite the first side 505. In one embodiment, the first side 505 of the connection surface 503 is configured to connect to a first portion of the boom 105, and the second side 507 of the connection surface 503 is configured to connect to a second portion of the boom 105, as described further below. The boom connection structure 501 may also include a plurality of holes 509 through which fasteners (e.g., bolts) pass to connect the boom 105 to the boom connection structure 501. As shown in FIG. 5A, the boom connection structure 501 is circular, but may be configured in any other shape.

[0021] 5B illustrates a boom 105 connected to a boom connection structure 501 according to one embodiment. In one embodiment, the first portion of the boom 105 is the nosecone 105A of the boom 105 and the second portion of the boom 105 is the main body 105B of the boom 105. As shown in FIG. 5B, the nosecone 105A of the boom 105 is connected to a first side 505 of the connection surface 503 of the boom connection structure 501, while the main body 105B of the boom 105 is connected to a second side 507 of the connection surface 503 of the boom connection structure 501. As a result, a portion of the nosecone 104A and a portion of the main body 105B of the boom 105 are attached to the inboard main wing 102.

[0022] In one embodiment, the width of the main body 105B of the boom 105 is substantially constant from a first end of the main body 105B of the boom 105 connected to the nose cone 105A to a second end of the main body 105B of the boom. In one embodiment, a tail cone 119 is connected to the second end of the main body 105B of the boom 105, as shown in FIG. 1C.

[0023] In one embodiment, the nose cone 105A of each boom 105 is configured to accommodate additional payload. The payload may be a sensor, such as a pitot tube 121, in the example shown in FIG. 1C. The pitot tube 121 is used to measure total and static pressure to obtain the dynamic pressure of the drone 100. The dynamic pressure can be used to calculate the airspeed of the drone 100. However, in other embodiments, other types of sensors may be contained within the nose cone 105A of each boom 105. For example, the nose cone 105A may accommodate at least one of a camera, radar, lidar, audio sensor, vibration sensor, intelligence, surveillance, and reconnaissance (ISR) equipment, a directional microphone, or a combination thereof.

[0024] In one embodiment, the main body 105B of each boom 105 extends aft relative to the front of the fuselage 101 such that the end of each boom is positioned past the fuselage 101. The main body 105B of the boom 105 includes connection points for connecting a plurality of horizontal stabilizers 111 and a plurality of vertical stabilizers 107 to the main body 105B of the boom 105. Figure 6 shows a tail connection surface located at the end of each boom 105 positioned past the fuselage 101 according to one embodiment.

[0025] In one embodiment, an end of the main body 105B of each boom 105 includes a first connection surface 601A configured to contact a connection surface of a corresponding horizontal stabilizer 111. The first connection surface 601A further includes an axle hole 603 that penetrates the thickness of the boom 105. The axle of the horizontal stabilizer 111 is inserted through the axle hole 603 to connect the horizontal stabilizer 111 to the horizontal stabilizer rotation mechanism, as described further below. In one embodiment, the main body 105B of each boom 105 further includes one or more second connection surfaces 601B. Each second connection surface is configured to contact a connection surface of a corresponding vertical stabilizer 107. For example, the main body 105B of each boom 105 can include a second connection surface 601B on the upper surface of the boom 105 for connecting the upper vertical stabilizer 107A to the boom 105, and a second connection surface 601B on the lower surface of the boom 105 for connecting the lower vertical stabilizer 107B to the boom 105.

[0026] 1A-1E, 4, and 7, a plurality of vertical stabilizers 107 are connected to each boom 105. The plurality of vertical stabilizers 107 connected to each boom 105 includes an upper vertical stabilizer 107A and a lower vertical stabilizer 107B. The upper vertical stabilizer 107A extends upward toward the sky from the upper surface of the boom 105 such that the upper vertical stabilizer 107A is located above the boom 105. In contrast, the lower vertical stabilizer 107B extends downward toward the ground from the lower surface of the boom 105 such that the lower vertical stabilizer 107B is located below the boom 105.

[0027] In one embodiment, one or more of the multiple vertical stabilizers 107 include a movable control surface 117, such as a rudder. The movable control surface 117 of the vertical stabilizer 107 includes a first end connected to a portion of the vertical stabilizer 107 and a second end not connected to the vertical stabilizer 107. The movable control surface 117 of the vertical stabilizer 107 pivots about the end connected to the portion of the vertical stabilizer 107 while maintaining a plane consistent with the direction of motion of the drone 100. To change the direction of motion of the drone 100 (e.g., yaw control), the movable control surface 117 can move (e.g., pivot) as shown in FIG. 7 .

[0028] 7, upper vertical stabilizer 107A includes a movable control surface 117, while lower vertical stabilizer 107B lacks a movable control surface 117. The movable control surfaces 117 of upper vertical stabilizer 107A can move together or can be controlled independently. In other embodiments, both upper vertical stabilizer 107A and lower vertical stabilizer 107B each include a corresponding movable control surface 117.

[0029] Referring to FIG. 8 , a horizontal stabilizer 111 according to one embodiment is shown. The horizontal stabilizer 111 includes a connecting surface 801. The connecting surface 801 is configured to contact the first connecting surface 601A of the boom 105 shown in FIG. 6 . The horizontal stabilizer 111 further includes a shaft 803 protruding from the connecting surface 801. The shaft 803 is configured to be inserted into the shaft hole 603 of the boom 105 and connect the horizontal stabilizer 111 to the boom 105. While the horizontal stabilizer 111 is connected to the boom 105, the horizontal stabilizer 111 has an anhedral angle (e.g., a 5° anhedral angle) relative to the boom 105. Various angles of the horizontal stabilizer 111 can be used depending on various load conditions and mission needs. For example, the horizontal stabilizer 111 can have a dihedral angle relative to the boom 105.

[0030] Referring to Figure 9, in one embodiment, the horizontal stabilizers 111 are movable. As shown in Figure 9, the horizontal stabilizers 111 are configured to rotate about axis 803. As shown in Figures 9, 13A, and 13B, the entire horizontal stabilizer 111 is configured to rotate more than just the trailing edge of the horizontal stabilizer 111. By rotating the horizontal stabilizer 111, the pitch of the drone 100 can be changed and the drone 100 can be stabilized about the longitudinal axis of the drone 100. In one embodiment, the horizontal stabilizers 111 are configured to rotate together. However, in other embodiments, the horizontal stabilizers 111 can move independently of each other.

[0031] 1A-1E, pylon 103 is configured to support thruster 109. A first end of pylon 103 is connected to the top surface of fuselage 101. A second end of pylon 103 extends upward from fuselage 101 in a skyward direction. Thruster 109 is attached to the second end of pylon 103.

[0032] In one embodiment, the pylon 103 is located at the rear end of the fuselage 101. Specifically, the pylon 103 is located so that the thrusters 109 are located at the center of lift of the drone 100. As such, the thrusters 109 are positioned to reduce the moment generated by the drone 100 body and to position the center of thrust as close as possible to the neutral axis of the drone 100 body, so that the weight of the thrusters 109 can provide stability to the drone 100 during flight.

[0033] For subsonic applications, the majority of the noise from the thrusters 109 extends from the front (e.g., inlet) of the thrusters 109 as opposed to the outlet (e.g., outlet) of the thrusters 109. By sweeping the pylons 103 aft and positioning the thrusters 109 on the inboard wings 102, the inboard wings 102 are used to shield any forward-extending fan noise component. The thrusters 109 are also positioned to reduce any moment produced by the airframe and position the center of thrust as close as possible to the neutral axis of the drone 100. This helps reduce the size of the required tail surface area, which helps reduce overall weight.

[0034] In one embodiment, the height of the pylon 103 is based on the diameter of the propeller 109. Specifically, the weight of the pylon 103 above the boundary layer of the inboard wing 102 may be at least 30% of the overall diameter of the propeller 109 to optimize fan efficiency and minimize distortion at the inlet of the propeller 109. A pylon height of at least 30% of the overall diameter of the propeller 109 is important for optimal fan efficiency.

[0035] The boundary layer of the inboard wing 102 is a thin film of air immediately adjacent to the interface formed by air flowing along the inboard wing 102. By positioning the propeller 109 above the boundary layer of the inboard wing 102 at a height that is at least 30% of the diameter of the propeller, the air entering the propeller 109 experiences significantly reduced inlet distortion (e.g., less than 0.1% distortion). Thus, the airflow into the inlet of the propeller 109 is substantially uniform, thereby reducing loss of propeller efficiency and any distortion.

[0036] Furthermore, noise emitted from the propeller 109 may be directed primarily outward due to the orientation of the fan surface of the propeller 109. By positioning the propeller 109 near the aft portion of the fuselage 101 and aft of the trailing edge of the inboard main wing 102, the aft portion of the inboard main wing 102 insulates the sensor located on the nose of the fuselage 101 from noise generated by the propeller 109.

[0037] As mentioned above, the propeller 109 is connected to the second end of the pylon 103 and is located above the fuselage 100. The propeller 109 is configured to generate thrust and propel the drone 100 forward. The rotors of the propeller 109 generate thrust when rotated at high speed and subjected to an airflow. The thrust may depend on the ratio of the speed of the rotor blade tips to the freestream airflow speed at the fan inlet (tip speed ratio). In one embodiment, the propeller 109 is a ducted propeller as described in U.S. Provisional Patent Application No. 63 / 356,885, filed June 29, 2023, which is incorporated by reference in its entirety. The ducted propeller allows for better shielding of load noise over more azimuth angles and also allows for greater thrust to be obtained closer to the drone 100's airframe. Furthermore, because the height of the pylon 103 above the inboard wing 102 is at least 30% of the total fan diameter of the propeller 109, the lower portion of the fan surface of the propeller 109, just above the boundary layer of the inboard wing 102, may be substantially free-stream, or as close to free-stream as possible, providing a substantially uniform flow at the inlet of the propeller 109 (i.e., a uniform circle, rather than different airflows between the lower and upper portions of the fan surface).

[0038] In one embodiment, the placement of the horizontal stabilizer 111 and boom 105 allows for a reduced wetted area for drag and mass reduction. By placing the horizontal stabilizer 111 outboard, the horizontal stabilizer 111 is not in the downwash, which complicates control and requires significant trimming variance during low speeds and takeoff. Therefore, the length of the boom 105 is determined according to airflow modeling that indicates the location of the downwash of the propeller 109. Furthermore, the length of the boom 105 is also determined according to airflow modeling so that the horizontal stabilizer 111 is positioned in the upwash region of the inboard wing 102 vortex around the boom. The effectiveness of the horizontal stabilizer 111 therefore increases as the vortex provides more lift. As a result, in cruise conditions, the horizontal stabilizer has a net lift vector oriented toward the forward flight direction, thereby providing a positive thrust component that reduces battery drain.

[0039] Additionally, the vortex shedding of the boom 105 also aids the effectiveness of the vertical stabilizer 107. Further aerodynamic optimization of the vortex shedding allows the size of the vertical stabilizer 107 to be reduced (tail volume factor) while maintaining similar or better performance relative to more conventional aircraft designs.

[0040] Horizontal stabilizer rotation As mentioned above, the horizontal stabilizers 111 are rotatable (e.g., movable). FIG. 10 shows a horizontal stabilizer rotation mechanism 1000 of the drone 100 configured to rotate a corresponding horizontal stabilizer 111 according to one embodiment. Each horizontal stabilizer 111 is connected to a corresponding horizontal stabilizer rotation mechanism 1000. In the embodiment described herein, the drone 100 includes two horizontal stabilizers 111. Thus, the drone 100 may include two horizontal stabilizer rotation mechanisms 1000, each located within a corresponding boom 105 of the drone 100. In one embodiment, each horizontal stabilizer rotation mechanism 1000 includes a servo mechanism (“servo”) 1001, a servo mount 1003, a servo arm 1007, a linkage 1009, a spline drive arm 1011, and a spline drive 1013. In other embodiments, the horizontal stabilizer rotation mechanism 1000 may have other components than those shown herein.

[0041] The servo 1001 is configured to control the angular position of the horizontal stabilizer 111. An example of a servo 1001 is a servo motor coupled to a sensor for position feedback and a controller that controls the servo motor. The servo 1001 has an output shaft that rotates to change the angular position of the horizontal stabilizer 111. In one embodiment, the output shaft of the servo 1001 is splined, i.e., the output shaft of the servo 1001 has ridges, teeth, or protrusions (e.g., male splines).

[0042] In one embodiment, the servo mount 1003 is configured to receive the servo 1001. The servo mount 1003 includes a cavity 1015. The servo 1001 is inserted (e.g., placed) within the cavity 1015. The servo 1001 is connected to the servo mount 1003 using one or more fasteners 1005 located on each end of the servo 1001. In one embodiment, the servo mount 1003 is connected to an inner surface of a corresponding boom 105. The servo mount 1003 is connected to the inner surface of the boom 105 via fasteners 1017.

[0043] In one embodiment, the servo arm 1007 is an intermediate connector located between the servo 1001 and the horizontal stabilizer 111. The servo arm 1007 is configured to rotate based on the rotation of the output shaft of the servo 1001. The servo arm 1007 includes a hole 1019 that passes through the entire thickness of the servo arm 1007. The output shaft of the servo 1001 is inserted into the hole 1019. In one embodiment, the hole 1019 of the servo arm 1007 has a groove (e.g., a female spline) that mates with a protrusion (e.g., a male spline) on the output shaft, connecting the output shaft of the servo 1001 to the servo arm 1007. When the output shaft of the servo 1001 rotates, the servo arm 1007 rotates in accordance with the rotation of the output shaft of the servo 1001.

[0044] In one embodiment, the servo arm 107 includes a slot 1021 that extends through the entire thickness of the servo arm 1007. The slot 1021 is configured to control the amount of rotation of the horizontal stabilizer 111, as described further below. The slot 1021 includes a first end adjacent the hole 1019 and a second end that is positioned adjacent the end of the servo arm 107.

[0045] Linkage 1009 is another intermediate connector located between servo 1001 and horizontal stabilizer 111. Linkage 1009 is configured to adjust the amount of rotation of horizontal stabilizer 111 based on the placement of linkage 1009 within slot 1021 of servo arm 1007. In one embodiment, linkage 1009 includes multiple Heim joints 1009A, 1009B and a length adjustment mechanism 1009B.

[0046] Each Heim joint 1009A, 1009B of linkage 1009 is located at opposite ends of linkage 1009. The first Heim joint 1009A is connected to servo arm 1007 through slot 1021 in servo arm 1021 via fasteners (e.g., nuts and bolts), and the second Heim joint 1009B is connected to spline drive arm 1011. The position of linkage 1009 along the length of slot 1021 affects the amount of rotation of horizontal stabilizer 111. For example, connecting linkage 1009 at a first end of slot 1021 adjacent to bore 1019 reduces the effective radius of rotation of servo arm 1021, thereby decreasing the amount of rotation of horizontal stabilizer 111, while connecting linkage 1009 at a second end of slot 1021 adjacent the end of servo arm 1021 increases the effective radius of rotation of servo arm 1021, thereby increasing the amount of rotation of horizontal stabilizer 111. The linkage 1009 can be connected to the servo arm 1007 along any position along the slot 1021 between the first and second ends of the slot 1021 to adjust the rotation of the horizontal stabilizer 111.

[0047] In one embodiment, length adjustment mechanism 1009B is configured to adjust the length of linkage 1007. Adjusting the length of linkage 1009 allows for fine adjustment of the initial position of horizontal stabilizer 111 in a non-rotating state. Length adjustment mechanism 1009B includes a threaded rod and multiple jam nuts. The threaded rod is threaded into both Heim joints 1009A and 1009B. As the jam nuts are rotated, the threaded rod either extends through Heim joints 1009A, 1009B, shortening the length of linkage 1009, or extends from Heim joints 1009A, 1009B, lengthening the length of linkage 1009, depending on the amount of rotation of the jam nuts.

[0048] The spline drive arm 1011 is another intermediate connection member located between the servo 1001 and the horizontal stabilizer 111. The spline drive arm 1011 is configured to receive the spline drive 1013. The spline drive arm 1011 includes a hole 1009 (see FIG. 11 ) that extends through the thickness of the spline drive arm 1011. As shown in FIG. 12 and as further described below, the spline drive 1013 is aligned with the hole 1009, and the spline drive 1013 is connected to the spline drive arm 1011 via a fastener. The spline drive arm 1011 is configured to rotate, such that the spline drive 1013 also rotates as the spline drive arm 1011 rotates. As shown in FIG. 10 , the spline drive arm 1011 is connected to a coupling 1000 (e.g., a Heim joint 1009B). As the servo 1001 rotates, the servo arm 1007 and linkage 1009 rotate, causing the spline drive arm 1011 and spline drive 1013 to also rotate.

[0049] 10, 11A, 11B, 11C, and 12, which illustrate the detailed views of the spline drive 1013, show the shaft 803 of the horizontal stabilizer 111 and the spline drive arm 1011 according to one embodiment. In one embodiment, as shown in FIG. 11A, the spline drive 1013 comprises a first end 1101 and a second end 1103. The first end 1103 of the spline drive 1013 comprises a plurality of fastening holes 1005. The plurality of fastening holes 1105 may be threaded, for example.

[0050] The spline drive arm 1011 includes a hole 1009 extending through the center of the spline drive arm 1011. The spline drive arm 1011 further includes a plurality of fastening holes 1111 having a smaller diameter than the hole 1009. The plurality of fastening holes 1111 in the spline drive arm 1011 are configured to align with the plurality of fastening holes in the first end of the spline drive 1013. A fastener (e.g., a bolt) 1201 is inserted through the fastening hole 1111 in the spline drive arm 1011 and the fastening hole 1105 in the spline drive 1013 to connect the spline drive arm 1011 and the spline drive 1013, as shown in FIG.

[0051] In one embodiment, the spline drive 1013 comprises a cavity in the center of the spline drive 1013. The cavity comprises a plurality of spline grooves (e.g., female splines) 1107, as shown in FIG. 11A. The spline grooves 1107 extend from a first end 1101 of the spline drive 1013 to a second end 1103 of the spline drive 1013. In one embodiment, the spline grooves 1107 taper from the first end 1101 of the spline drive 1013 towards the second end 1103 of the spline drive 1013, thereby forming a cone-like shape.

[0052] 11B, in one embodiment, the shaft 803 of the horizontal stabilizer 111 includes a plurality of spline protrusions 1113 (e.g., male splines) at the end of the shaft 803. The spline protrusions 1113 mate with the spline grooves 1107 at the spline drive 1107. Thus, as shown in FIG. 11B, the spline protrusions 1113 taper from the base of the spline protrusions 1113 to the end of the spline protrusions 1113. The taper of the spline protrusions 1113 mates with the taper of the spline grooves 1107.

[0053] 12, the shaft 803 is configured to be inserted through the shaft hole 603 of the boom 105 and through the hole 1009 of the spline drive 1011 so that the spline protrusion 1113 is inserted into the spline groove 1107 of the spline drive 1107. When the spline protrusion 1113 contacts the spline groove 1107, the horizontal stabilizer 111 is connected to the horizontal stabilizer rotation mechanism 1000 and can rotate.

[0054] 13A and 13B show various views of the horizontal stabilizer 111 in various rotational (e.g., tilt) states according to one embodiment. When the servo 1001 rotates, the intermediate connector also rotates as described above. When the intermediate connector rotates, the axis 803 of the horizontal stabilizer 111 also rotates, causing the entire horizontal stabilizer 111 to rotate (e.g., tilt) between different angles. Thus, rather than rotating a portion of the horizontal stabilizer 111, the entire horizontal stabilizer 111 rotates. In one embodiment, the horizontal stabilizer 111 is configured to rotate up to 90° from a no-rotation position of the horizontal stabilizer 111.

[0055] As described above, each horizontal stabilizer rotation mechanism 1000 is housed in a corresponding boom 105. The horizontal stabilizer rotation mechanisms 1000 may periodically require maintenance and / or adjustment. In one embodiment, each boom 105 includes multiple access panels 1401, as shown in FIG. 14A . Each access panel 1401 is secured to the exterior surface of the boom 105 via fasteners and can rotate to provide access to a portion of the horizontal stabilizer rotation mechanism 1000. In one embodiment, the access panels 1401 include a first access panel 1401A and a second access panel 1401B. The first access panel 1401A is located on one side of the boom 105, and the second access panel 1401B is located on the other side of the boom 105.

[0056] In one embodiment, first access panel 1401A is rotatable and, when removed from first access panel 1401A, exposes linkage 1009 and spline drive 1013, as shown in Figure 14. The length of linkage 1009 is adjustable and / or spline drive 1013 can be inspected by removing first access panel 1401A. In one embodiment, second access panel 1401B is removed and, when second access panel 1401B is removed, exposes servo 1001, as shown in Figure 14C.

[0057] Second embodiment of the drone structure 15 shows a perspective view of a drone 1500 according to another embodiment. The drone 1500 includes similar components to the drone 100 described above. For example, the drone 1500 includes a fuselage 101, a main wing 102 proximal to the fuselage, a pylon 103, a thruster 109, multiple booms 105, multiple horizontal stabilizers 111 (e.g., wings), and multiple vertical stabilizers 107 (e.g., wings). However, in contrast to the drone 100, the drone 1500 includes two lower vertical stabilizers 107B but lacks the upper vertical stabilizer 107A shown on the drone 100.

[0058] References in the specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic is included in at least one embodiment of the disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

[0059] While the present disclosure has been particularly shown and described with reference to one embodiment and several alternative embodiments, 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.

Claims

1. It is a drone, The torso and an inboard wing attached to an upper surface of the fuselage, the inboard wing having a first end and a second end opposite the first end; a pylon located toward the aft end of the fuselage, the pylon having an end extending from the upper surface of the fuselage such that the end of the pylon is located higher than the inboard wing; a propeller connected to the end of the pylon, the propeller configured to generate thrust; and a plurality of booms including a first boom attached to the first end of the inboard wing and a second boom attached to the second end of the inboard wing; a plurality of horizontal stabilizers including a first horizontal stabilizer connected to a side of the first boom and extending outward from the propeller, and a second horizontal stabilizer connected to a side of the second boom and extending outward from the propeller; The drone, wherein each of the plurality of horizontal stabilizers is configured to rotate as a whole.

2. The drone of claim 1 , wherein the propulsor connected to the end of the pylon is a ducted propulsor located at the center of lift of the drone.

3. The drone of claim 1 , wherein the height of the pylon above the inboard wing is based on the diameter of the propulsion device.

4. The drone of claim 3 , wherein the height of the pylon is at least 30% of the diameter of the propulsion device.

5. 2. The drone of claim 1, wherein the first boom and the second boom each have a respective end positioned past the rear end of the fuselage.

6. 6. The drone of claim 5, wherein the first horizontal stabilizer is attached to the end of the first boom past the aft end of the fuselage, and the second horizontal stabilizer is attached to the end of the second boom past the aft end of the fuselage.

7. 7. The drone of claim 6, wherein the first length of the first boom is such that the first horizontal stabilizer is located in an upwash region of the inboard wing swirl about the first boom, and the second length of the second boom is such that the second horizontal stabilizer is located in the upwash region of the inboard wing swirl about the second boom.

8. 2. The drone of claim 1, wherein the first horizontal stabilizer includes an anhedral angle or a dihedral angle relative to the first boom, and the second horizontal stabilizer includes the anhedral angle or the dihedral angle relative to the second boom.

9. 2. The drone of claim 1, wherein the first horizontal stabilizer comprises a first connection surface configured to contact the first boom and a first shaft protruding from the first connection surface, and the second horizontal stabilizer comprises a second connection surface configured to contact the second boom and a second shaft protruding from the second connection surface.

10. The drone is 10. The drone of claim 9, further comprising a plurality of horizontal stabilizer rotation mechanisms, each configured to rotate a corresponding one of the plurality of horizontal stabilizers, the plurality of horizontal stabilizer rotation mechanisms comprising: a first horizontal stabilizer rotation mechanism located in the first boom and configured to rotate the first horizontal stabilizer; and a second horizontal stabilizer rotation mechanism located in the second boom and configured to rotate the second horizontal stabilizer.

11. Each of the first horizontal tail rotation mechanism and the second horizontal tail rotation mechanism comprises: a mount attached to an inner surface of a corresponding boom, the mount comprising a cavity; a servo mechanism located within the cavity of the mount, the servo mechanism including an output shaft configured to rotate; and a servo arm configured to rotate about the output shaft, the servo arm including a hole, the output shaft of the servo mechanism being inserted into the hole of the servo arm such that the servo arm rotates with rotation of the output shaft; a linkage having a first end and a second end, the first end of the linkage being connected to the servo arm such that the linkage is configured to rotate about the output shaft as the servo arm rotates; a splined drive arm connected to the second end of the coupling, the splined drive arm including a hole, the splined drive arm configured to rotate as the coupling rotates about the output shaft; 11. The drone of claim 10, comprising: a spline drive inserted into the hole in the spline drive arm, the spline drive configured to rotate as the spline drive arm rotates.

12. 12. The drone of claim 11, wherein the spline drive comprises a cavity having a plurality of spline grooves, and the first shaft and the second shaft each comprise a plurality of spline protrusions at an end of the first shaft and the second shaft that mate with the plurality of spline grooves.

13. the first boom includes a first axial hole extending through a thickness of the first boom, and the second boom includes a second axial hole extending through a thickness of the second boom; The first shaft is configured to be inserted into the first shaft hole and the corresponding hole of the spline drive arm so that the plurality of spline protrusions of the first shaft are inserted into the plurality of spline grooves of the corresponding spline drive; 13. The drone of claim 12, wherein the second shaft is configured to be inserted into the second shaft hole and the corresponding hole of the spline drive arm such that the plurality of spline protrusions of the second shaft are inserted into the plurality of spline grooves of the corresponding spline drive.

14. 13. The drone of claim 12, wherein the plurality of spline protrusions of each of the first shaft and the second shaft taper toward an end of the corresponding shaft, and the plurality of spline grooves of each corresponding spline drive taper from a first end of the corresponding spline drive toward a second end of the corresponding spline drive.

15. the servo arm further comprises a slot extending from a first end of the slot adjacent the hole in the servo arm to a second end of the slot located toward an end of the servo arm; 12. The drone of claim 11, wherein the first end of the linkage is connected to the servo arm through the slot, and the corresponding degree of tail rotation is adjustable based on a connection position of the first end of the linkage along the slot.

16. 12. The drone of claim 11, wherein each of the first boom and the second boom comprises a plurality of access covers configured to be detached from the first boom and the second boom to expose different portions of the first horizontal stabilizer rotation mechanism and the second horizontal stabilizer rotation mechanism.

17. 10. The drone of claim 1, wherein the fuselage comprises a nose configured to accommodate a payload including at least one of a camera, a radar, a lidar, an audio sensor, a vibration sensor, an intelligence, surveillance, and reconnaissance (ISR) device, a directional microphone, or a combination thereof.

18. Each of the first boom and the second boom includes a main body having a first end and a second end opposite the first end; a nosecone attached to the first end of the main body; a tail cone attached to the second end of the main body; The drone of claim 1 , wherein a portion of the nosecone and a portion of the main body are connected to corresponding ends of the inboard wing.

19. 20. The drone of claim 18, wherein the nose cone is configured to accommodate a payload including at least one of a camera, a radar, a lidar, an audio sensor, a vibration sensor, an intelligence, surveillance, and reconnaissance (ISR) device, a directional microphone, or a combination thereof.

20. a first plurality of vertical stabilizers connected to the end of the first boom, the first plurality of vertical stabilizers comprising a first vertical stabilizer extending upward from an upper surface of the first boom and a second vertical stabilizer extending downward from a lower surface of the first boom on an opposite side to the upward direction; a second plurality of vertical stabilizers connected to the end of the second boom, the second plurality of vertical stabilizers comprising: a third vertical stabilizer extending upward from an upper surface of the second boom; and a fourth vertical stabilizer extending downward from a lower surface of the second boom opposite the upward direction; The drone of claim 6 , wherein the first vertical stabilizer and the third vertical stabilizer include rudder(s), and the second vertical stabilizer and the fourth vertical stabilizer each lack the rudder(s).

21. a plurality of vertical stabilizers, including a first vertical stabilizer and a second vertical stabilizer; 7. The drone of claim 6, wherein the first vertical stabilizer is attached to an underside of the first boom and extends downwardly from the underside of the first boom, and the second vertical stabilizer is attached to an underside of the second boom and extends downwardly from the underside of the second boom.

Images