Ultra-silence unmanned aerial vehicle

Abstract

A drone with low acoustic features is disclosed. The drone includes a fuselage, a main inner wing attached to the fuselage, a pylon facing a rear end of the fuselage and having an end higher than the main inner wing, and a propeller connected to the pylon and located above the fuselage. The drone includes a plurality of booms connected to the main inner wing and a plurality of horizontal tails attached to the plurality of booms. The horizontal tail has an outboard tail arrangement and is tiltable.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Patent Application No. 18 / 181,067, filed on March 9, 2023, which claims the benefit of U.S. Provisional Patent Application No. 63 / 356,885, filed on June 29, 2022, the entireties of which are incorporated herein by reference. Background Art Technical Field

[0003] The present disclosure relates generally to an unmanned aerial vehicle, and more particularly to an unmanned aerial vehicle with reduced noise pollution.

[0004] Related technical description

[0005] Conventional drones include propeller fans that typically include open rotors and propellers. These types of conventional drones have reached their sound limits. As a result, conventional drones contribute to noise pollution. Summary of the invention

[0006] A drone that reduces noise pollution is described. In one embodiment, the drone includes a fuselage and a main inner wing attached to an upper surface of the fuselage. A pylon is attached toward a rear end of the fuselage and extends such that an end of the pylon is positioned higher than the main inner wing. A propeller configured to generate thrust is attached to the end of the pylon.

[0007] Thus, the propeller is positioned at the center of lift of the drone to provide a sound shield near the main inner wing. The noise emitted by the propeller can be radiated outwardly mainly in the direction of the fan face of the propeller. Since the propeller is placed behind the trailing edge of the main inner wing, the main inner wing can provide a sound shield on the leading edge side of the wing, where the payload can be closer.

[0008] In addition, the drone includes a plurality of booms attached to the main inner wings. A plurality of tail fins are attached to the ends of the booms. In one embodiment, the tail fins have an outboard tail arrangement to reduce the wetted area, thereby reducing drag and mass. The horizontal tail fins may also rotate to provide longitudinal stability in all phases of flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A A top front left perspective view of a drone is illustrated according to an embodiment.

[0010] Figure 1B A top front perspective view of a drone is illustrated according to an embodiment.

[0011] Figure 1C A top left perspective view of a drone is illustrated according to an embodiment.

[0012] Figure 1D A top right perspective view of a drone is illustrated according to an embodiment.

[0013] Figure 1E A top rear perspective view of a drone according to an embodiment is illustrated.

[0014] Figure 2 An internal view of a fuselage of a drone according to an embodiment is illustrated.

[0015] Figure 3A and Figure 3B Different views of a payload in the fuselage of a drone are illustrated according to an embodiment.

[0016] Figure 4 Ailerons and flaperons of a drone according to an embodiment are illustrated.

[0017] Figure 5A A boom connection structure at the end of a main inner wing of a drone according to an embodiment is illustrated.

[0018] Figure 5B A boom connected to an end of a main inner wing via a boom connection structure according to an embodiment is illustrated.

[0019] Figure 6 A tail connection surface at the end of a boom of a drone according to an embodiment is illustrated.

[0020] Figure 7 The movable control surfaces of the vertical tail of a drone according to an embodiment are illustrated.

[0021] Figure 8 A perspective view of a horizontal tail of a drone according to an embodiment is illustrated.

[0022] Fig. 9 A movable horizontal tail of a drone according to an embodiment is illustrated.

[0023] Fig.10 The horizontal tail rotation mechanism of the UAV according to the embodiment is illustrated.

[0024] Fig.11A A detailed view of a spline drive of a horizontal tail rotation mechanism is illustrated in accordance with an embodiment.

[0025] Fig. 11B A detailed view of the axis of the horizontal tail of a drone according to an embodiment is illustrated.

[0026] Fig. 11C A detailed view of a spline drive arm of a horizontal tail rotation mechanism is illustrated in accordance with an embodiment.

[0027] Fig.12A process for connecting a tailplane to a tailplane rotation mechanism according to an embodiment is illustrated.

[0028] Fig.13A and Fig. 13B is a detailed view of a horizontal tail in different rotational positions according to an embodiment.

[0029] Fig.14A A plurality of access covers in the boom are illustrated to access the horizontal tail rotation mechanism according to an embodiment.

[0030] Fig. 14B A first portion of a horizontal tail rotation mechanism accessible through a first access cover is illustrated according to an embodiment.

[0031] Fig. 14C A second portion of the horizontal tail rotation mechanism accessible through a second access cover is illustrated according to an embodiment.

[0032] Fig.15 A perspective view of a drone is shown according to another embodiment. DETAILED DESCRIPTION

[0033] The accompanying drawings (figures) and the following description describe certain 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 illustrated herein may be employed without departing from the principles described herein. Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying drawings. It is noted that, where feasible, similar or like reference numerals may be used in the drawings and may indicate similar or like functions.

[0034] First embodiment of the drone structure

[0035] Figure 1A , Figure 1B , Figure 1C , Figure 1D and Figure 1E 1 illustrates different perspective views of a drone 100 according to an embodiment. Specifically, according to an embodiment, Figure 1A A top front left perspective view of the drone 100 is illustrated. Figure 1B A top front perspective view of the drone 100 is illustrated. Figure 1C A top left perspective view of the drone 100 is illustrated. Figure 1D A top right perspective view of the drone 100 is illustrated, and Figure 1E A top rear perspective view of a drone 100 is illustrated. In one embodiment, the drone 100 is a low altitude, Class II small unmanned aircraft 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.

[0036] In one embodiment, drone 100 (e.g., aircraft) includes fuselage 101, main inner wing 102, pylon 103, propeller 109, multiple booms 105, multiple horizontal tails 111 (e.g., wings), and multiple vertical tails 107 (e.g., wings). Horizontal tails 111 and vertical tails 107 together form the tail of drone 100. It should be noted that in other embodiments, drone 100 may include other than Figures 1A to 1E Components other than those shown.

[0037] The fuselage 101 is the main body of the drone 100. The fuselage 101 is a hollow structure. The fuselage 101 can be a continuous structure, or can be a modular structure that includes multiple components that together form the fuselage 101. In one embodiment, the fuselage 101 contains one or more payloads. For example, the fuselage 101 contains Figure 2 The power supply 201 shown, Figure 2 An internal view of the fuselage 101 is illustrated. The power source 201 includes one or more batteries (e.g., 22,000 mAh lithium polymer batteries or advanced lithium air batteries) for powering the drone 100. In one embodiment, the drone 100 is fully electric. However, in other embodiments, the drone 100 may utilize a hybrid electric system to achieve longer endurance, more payload, and / or longer range.

[0038] In one embodiment, the fuselage 101 includes an interior space 301 at the nose of the fuselage 101, the interior space containing one or more payloads. Figure 3A and Figure 3B As shown, the interior space 301 may be located at the front portion (eg, the nose) of the fuselage 101 . However, the interior space 301 may be located at other portions of the fuselage 101 .

[0039] An example of a payload located in the interior space 301 is a camera 303. Figure 3A and Figure 3B As shown, camera 303 may be oriented forward for capturing content such as images and / or video while drone 100 is in flight. A portion of the front of fuselage 101 defining interior space 301 may be made of a transparent material such as plastic or glass to allow camera 303 to capture content. Other examples of payloads that may be housed within fuselage 101 include one or more sensors such as radar, lidar, audio sensors, vibration sensors, other intelligence, surveillance, reconnaissance (ISR) equipment, directional microphones, or some combination thereof.

[0040] In one embodiment, the fuselage 101 may also 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 devices) for controlling the propellers 109 and actuating one or more control surfaces of the drone 100 (e.g., controlling ailerons, rudders, elevators, ailerons, flaps, spoilers, leading edge slats, etc.).

[0041] In one embodiment, one or more landing mechanisms may be attached to the bottom surface of the fuselage 101. The landing mechanism may be a landing gear (eg, a tricycle landing gear) or a landing skid.

[0042] Re-reference Figures 1A to 1E , the main inner wing 102 is attached to the upper surface of the fuselage 101, which is opposite to the bottom surface of the fuselage 101. The main inner wing 102 is a central element that connects the fuselage 101, the boom 105, the pylon 103 and the propeller 109 together. The main inner wing 102 is located between a first end (e.g., the front) and a second end (e.g., the rear) of the fuselage 101. The main inner wing 102 is configured to provide flight lift for the drone 100 and has an upper dihedral angle relative to the fuselage 101 to provide stability and improved sensor viewing angle, as further described below in one embodiment. The main inner wing 102 can be made of a composite material such as carbon fiber, a metal (e.g., aluminum or titanium), or an alloy.

[0043] In one embodiment, the main inner wing 102 includes 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 main inner 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 main inner wing 102 may be separate structures, each coupled to the upper surface of the fuselage 2101.

[0044] like Figures 1A to 1E As shown, the upper surface (eg, top surface) of the main inner wing 102 is curved. The upper surface of the main inner wing 102 slopes downward from the leading edge of the main inner wing 102 to the trailing edge of the main inner wing 102. Figure 4 The main inner wing 102 includes a plurality of control surfaces at the trailing edge of the main inner wing 102 that control the drone 100 during flight. In one embodiment, the control surfaces include a plurality of ailerons 113 and a plurality of flaperons 115.

[0045] In one embodiment, the first side 102A and the second side 102B of the main inner wing 102 each include one or more ailerons 113, which are wingtips toward the trailing edge of the main inner wing 102. In addition, the trailing edge of the first side 102A and the second side 102B of the main inner wing 102 each include one or more flaperons 115. The flaperons 115 on each side of the main inner wing 102 are located between the corresponding ailerons 113 and the fuselage 101, such as Figure 4 shown.

[0046] One end of each aileron 113 and flaperon 115 is configured to be attached to the trailing edge of the main inner wing 102. Each aileron 113 and flaperon 115 is configured to rotate about the attachment point with the trailing edge of the main inner wing 102 to control the movement of the drone 100 during flight, such as Figure 4 For example, ailerons 113 are used to control the roll of drone 100 (e.g., movement about the longitudinal axis of the drone), which results in a change in flight path due to the tilt of the lift vector, referred to as "roll" or "tilt." Flaperons 115 control the lift and drag of drone 100 by rotating and / or extending inwardly or outwardly from the trailing edge of main inner wing 102.

[0047] In one embodiment, the wing tips of the main inner wings 102 each include a boom connection structure 501, such as Figure 5A As shown. The boom connection structure 501 is configured to attach a corresponding boom 105 to each wingtip of the main inner wing 102. The boom connection structure 501 is a plate-like structure that includes a connection surface 503 to connect the boom to the main inner 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 will be further described 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 Figure 5A As shown, the boom connection structure 501 is circular, but can be configured into any other shape.

[0048] Figure 5B The boom 105 is illustrated connected to the boom connection structure 501 according to one embodiment. In one embodiment, the first portion of the boom 105 is the head cone 105A of the boom 105, and the second portion of the boom 105 is the body 105B of the boom 105. Figure 5BAs shown, the head cone 105A of the boom 105 is connected to a first side 505 of the connection surface 503 of the boom connection structure 501, and the body 105B of the boom 105 is connected to a second side 507 of the connection surface 503 of the boom connection structure 501. Therefore, a portion of the head cone 104A and a portion of the body 105B of the boom 105 are attached to the main inner wing 102.

[0049] 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 head vertebra 105A) to a second end of the main body 105B of the boom. In one embodiment, the tail vertebra 119 is connected to the second end of the main body 105B of the boom 105, such as Figure 1C shown.

[0050] In one embodiment, the head cone 105A of each boom 105 is configured to accommodate an additional payload. Figure 1C In one example shown, the payload may be a sensor, such as a pitot tube 121. The pitot tube 121 is used to measure stagnation pressure and static pressure to obtain a dynamic pressure of the drone 100. The dynamic pressure may be used to calculate the airspeed of the drone 100. However, in other embodiments, other types of sensors may be included in the head cone 105A of each boom 105. For example, the head cone 105A may house at least one of a camera, a radar, a lidar, an audio sensor, a vibration sensor, intelligence, surveillance, reconnaissance (ISR) equipment, a directional microphone, or a combination thereof.

[0051] In one embodiment, the body 105B of each boom 105 extends rearwardly relative to the front of the fuselage 101 so that the end of each boom is located behind the end of the fuselage 101. The body 105B of the boom 105 includes connection points for connecting the plurality of horizontal tail planes 111 and the plurality of vertical tail planes 107 to the body 105B of the boom 105. Figure 6 The empennage connection surface is illustrated at the end of each boom 105, which is located behind the fuselage 101, according to one embodiment.

[0052] In one embodiment, the end of the body 105B of each boom 105 includes a first connection surface 601A, which is configured to contact the connection surface of the corresponding horizontal tail 111. The first connection surface 601A also includes an axis hole 603 that penetrates the thickness of the boom 105. The axis of the horizontal tail 111 is inserted through the axis hole 603 to connect the horizontal tail 111 to the horizontal tail rotation mechanism, as will be further described below. In one embodiment, the body 105B of each boom 105 also includes one or more second connection surfaces 601B. Each second connection surface is configured to contact the connection surface of the corresponding vertical tail 107. For example, the body 105B of each boom 105 may include a second connection surface 601B at the upper surface of the boom 105 for connecting the upper vertical tail 107A to the boom 105, and a second connection surface 601B at the lower surface of the boom 105 for connecting the lower vertical tail 107B to the boom 105.

[0053] In one embodiment, a plurality of vertical tail fins 107 are connected to each boom 105, such as Figures 1A to 1E , Figure 4 and Figure 7 As shown. The plurality of vertical tails 107 connected to each boom 105 include an upper vertical tail 107A and a lower vertical tail 107B. The upper vertical tail 107A extends from the upper surface of the boom 105 toward the sky in an upward direction, so that the upper vertical tail 107A is higher than the boom 105. On the contrary, the lower vertical tail 107B extends from the lower surface of the boom 105 toward the ground in a downward direction, so that the lower vertical tail 107B is lower than the boom 105.

[0054] In one embodiment, one or more of the plurality of vertical tail fins 107 include a movable control surface 117, such as a rudder. The movable control surface 117 of the vertical tail fin 107 includes a first end connected to a portion of the vertical tail fin 107 and a second end not connected to the vertical tail fin 107. The movable control surface 117 of the vertical tail fin 107 rotates around the end (connected to the portion of the vertical tail fin 107) so that the body is aligned with the direction of movement of the drone 100. In order to change the direction of movement of the drone 100 (e.g., yaw control), the movable control surface 117 can be moved (e.g., rotated), such as Figure 7 shown.

[0055] exist Figure 7 In the example shown, the upper vertical tail 107A includes a movable control surface 117, but the lower vertical tail 107B does not include a movable control surface 117. The movable control surfaces 117 of the upper vertical tail 107A move simultaneously or can be controlled independently. In other embodiments, the upper vertical tail 107A and the lower vertical tail 107 each include a corresponding movable control surface 117.

[0056] refer to Figure 8 , shows a horizontal tail 111 according to one embodiment. The horizontal tail 111 includes a connection surface 801. The connection surface 801 is configured to contact the first connection surface 601A of the boom 105, such as Figure 6 Horizontal tail 111 also includes shaft 803 protruding from connection surface 801. Shaft 803 is configured to be inserted into shaft hole 603 of boom 105 to connect horizontal tail 111 to boom 105. When horizontal tail 111 is connected to boom 105, horizontal tail 111 has a downward angle (e.g., a downward angle of 5°) relative to boom 105. Different angles of horizontal tail 111 can be adopted according to different load conditions and mission requirements. For example, horizontal tail 111 can have an upward angle relative to boom 105.

[0057] refer to Fig. 9 In one embodiment, the horizontal tail 111 is movable. The horizontal tail 111 is configured to rotate about the axis 803, such as Fig. 9 As shown. Fig. 9 , Fig.13A and Fig. 13B As shown, the entire horizontal tail 111 is configured to rotate, rather than just the trailing edge of the horizontal tail 111. By rotating the horizontal tail 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 tails 111 are configured to rotate simultaneously. However, in other embodiments, the horizontal tails 111 can move independently of each other.

[0058] Re-reference Figures 1A to 1E , the pylon 103 is configured to support the propeller 109. A first end of the pylon 103 is connected to an upper surface of the fuselage 101. A second end of the pylon 103 extends upward from the fuselage 101 in a direction toward the sky. The propeller 109 is attached to the second end of the pylon 103.

[0059] In one embodiment, the pylon 103 is placed at the rear end of the fuselage 101. Specifically, the pylon 103 is placed so that the propeller 109 is located at the center of lift of the drone 100. Therefore, when flying, the weight of the propeller 109 can provide stability to the drone 100 because the position of the propeller 109 can reduce the moment generated on the fuselage of the drone 100 and place the center of thrust as close to the neutral axis of the fuselage of the drone 100 as possible.

[0060] For subsonic applications, most of the noise from the propeller 109 emanates from the front of the propeller 109 (e.g., inlet), rather than from the exhaust (e.g., outlet) of the propeller 109. By offsetting the pylon 103 rearward and positioning the propeller 109 above the main inner wing 102, the main inner wing 102 serves to shield any forward-emitting fan noise components. The location of the propeller 109 also reduces any moments generated on the fuselage and places the center of thrust as close to the neutral axis of the drone 100 as possible. This helps reduce the size of the tail surface area required, thereby contributing to overall weight savings.

[0061] In one embodiment, the height of the pylon 103 is based on the diameter of the propeller 109. Specifically, the height of the pylon 103 above the boundary layer of the main inner wing 102 may be at least 30% of the overall diameter of the propeller 109 to achieve the goals of optimal fan efficiency and minimal inlet distortion of the propeller 109. It is critical for optimal fan efficiency that the height of the pylon be at least 30% of the overall diameter of the propeller 109.

[0062] The boundary layer of the main inner wing 102 is a thin layer of air in the immediate vicinity of the boundary surface formed by the air flowing along the main inner wing 102. By placing the propeller 109 at a height above the boundary layer of the main inner wing 102 (the height being at least 30% of the diameter of the propeller), the inlet distortion of the air entering the propeller 109 is significantly reduced (e.g., less than 0.1% distortion). Therefore, the airflow flowing into the inlet of the propeller 109 is substantially uniform, thereby reducing the loss of propeller efficiency and any distortion.

[0063] Additionally, the noise emitted by the propeller 109 may be radiated primarily outward in the direction of the fan face of the propeller 109. By placing the propeller 109 near the rear of the fuselage 101 and behind the trailing edge of the main inner wing 102, the rear of the main inner wing 102 provides acoustic shielding for sensors located in the nose of the fuselage 101 from the noise emitted by the propeller 109.

[0064] As described 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 to propel the drone 100 in a forward direction. The rotor of the propeller 109 generates thrust when rotating at a speed and when providing airflow. The thrust may depend on the ratio of the tip speed of the rotating blades of the rotor to the free 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 on June 29, 2023, which is incorporated herein by reference in its entirety. The ducted propeller allows additional shielding of load noise across more azimuth angles and allows higher thrust to be closer to the fuselage of the drone 100. Furthermore, because the height of the pylon 103 above the main inner wing 102 is at least 30% of the total fan diameter of the propeller 109, the bottom of the fan surface of the propeller 109 just above the boundary layer of the main inner wing 102 can be substantially free stream or as close to free stream as possible, resulting in substantially uniform airflow to the inlet of the propeller 109 (i.e., a uniform airflow circle rather than different airflows between the bottom and top of the fan surface).

[0065] In one embodiment, the placement of the horizontal tail 111 and the boom 105 allows for a reduction in wetted area, thereby reducing drag and mass. By placing the horizontal tail 111 on the outside, the horizontal tail 111 is not in the downwash of the propeller 109, which complicates control at low speed and takeoff and requires greater adjustments. Therefore, the length of the boom 105 is determined based on an airflow model that indicates the location of the downwash of the propeller 109. In addition, the length of the boom 105 is also determined based on the airflow model so that the horizontal tail 111 is positioned at the upwash flow field where the vortex of the main inner wing 102 rolls up around the boom. Therefore, the effect of the horizontal tail 111 is improved as the vortex rolls up to provide additional lift. Therefore, under cruise conditions, the horizontal tail has a net lift vector pointing in the direction of forward flight, as well as a positive thrust component, thereby reducing battery consumption.

[0066] Additionally, vortex roll-up from boom 105 also contributes to the effect of vertical tail 107. Further aerodynamic optimization of vortex roll-up allows the size (tail volume factor) of vertical tail 107 to be smaller relative to more conventional aircraft designs while maintaining similar or better performance.

[0067] Horizontal tail rotation

[0068] As described above, tailplane 111 is rotatable (eg, movable). Fig.10A horizontal tail rotation mechanism 1000 of a drone 100 configured to rotate a corresponding horizontal tail 111 according to an embodiment is illustrated. Each horizontal tail 111 is connected to a corresponding horizontal tail rotation mechanism 1000. In the embodiment described herein, the drone 100 includes two horizontal tails 111. Therefore, the drone 100 may include two horizontal tail rotation mechanisms 1000, each located within a corresponding boom 105 of the drone 100. In one embodiment, each horizontal tail rotation mechanism 1000 includes a servo mechanism ("servo") 1001, a servo mount 1003, a servo arm 1007, a connecting rod 1009, a spline drive arm 1011, and a spline drive 1013. In other embodiments, the horizontal tail rotation mechanism 1000 may have other components in addition to the components shown herein.

[0069] Servo 1001 is configured to control the angular position of horizontal tail 111. An example of servo 1001 is a servo motor that is coupled to a sensor (for position feedback) and a controller (to control the servo motor). Servo 1001 includes an output shaft that rotates to change the angular position of horizontal tail 111. In one embodiment, the output shaft of servo 1001 is splined. That is, the output shaft of servo 1001 includes ridges, teeth, or protrusions (e.g., male splines).

[0070] In one embodiment, the servo mount 1003 is configured to accommodate the servo 1001. The servo mount 1003 includes a cavity 1015. The servo 1001 is inserted (e.g., placed) in the cavity 1015. The servo 1001 is connected to the servo mount 1003 using one or more fasteners 1005 located at each end of the servo 1001. In one embodiment, the servo mount 1003 is connected to the inner surface of the corresponding boom 105. The servo mount 1003 is connected to the inner surface of the boom 105 via fasteners 1017.

[0071] In one embodiment, the servo arm 1007 is an intermediate connection member between the servo 1001 and the horizontal tail 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 penetrates 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 107 has a groove (e.g., a female spline) that matches the protrusion (e.g., a male spline) of the output shaft to connect the output shaft of the servo 1001 to the servo arm 1007. As the output shaft of the servo 1001 rotates, the servo arm 1007 rotates according to the rotation of the output shaft of the servo 1001.

[0072] In one embodiment, servo arm 107 includes a slot 1021 that penetrates the entire thickness of servo arm 1007. Slot 1021 is configured to control the amount of rotation of horizontal tail 111, as will be further described below. Slot 1021 includes a first end adjacent to hole 1019 and a second end adjacent to an end of servo arm 107.

[0073] Link 1009 is another intermediate connection positioned between servo 1001 and horizontal tail 111. Link 1009 is configured to adjust the amount of rotation of horizontal tail 111 based on placement of link 1009 within slot 1021 of servo arm 1007. In one embodiment, link 1009 includes a plurality of heim joints 1009A, 1009B and a length adjustment mechanism 1009B.

[0074] Each heim joint 1009A, 1009B of the link 1009 is located at opposite ends of the link 1009. The first heim joint 1009A is connected to the servo arm 1007 via fasteners (e.g., nuts and bolts) through the slot 1021 of the servo arm 1021, and the second heim joint 1009B is connected to the spline drive arm 1011. The location of the link 1009 along the length of the slot 1021 affects the amount of rotation of the horizontal tail 111. For example, connecting the link 1009 at the first end of the slot 1021 adjacent to the hole 1019 reduces the amount of rotation of the horizontal tail 111 because the effective rotation radius of the servo arm 1021 is reduced, while connecting the link 1009 at the second end of the slot 1021 adjacent to the end of the servo arm 1021 increases the amount of rotation of the horizontal tail 111 because the effective rotation radius of the servo arm 1021 is increased. Link 1009 may be connected to servo arm 1007 at any location along slot 1021 between the first and second ends of slot 1021 to adjust the rotation of horizontal tail 111 .

[0075] In one embodiment, the length adjustment mechanism 1009B is configured to adjust the length of the connecting rod 1007. By adjusting the length of the connecting rod 1009, the initial position of the horizontal tail 111 in the non-rotating state can be fine-tuned. The length adjustment mechanism 1009B includes a threaded rod and a plurality of lock nuts. The threaded rod is screwed into the heim joints 1009A and 100B, and as the lock nuts rotate, the threaded rod is either inserted deeper into the heim joints 1009A, 1009B to reduce the length of the connecting rod 1009, or extends from the heim joints 1009A, 1009B to increase the length of the connecting rod 1009, depending on the amount of rotation of the lock nuts.

[0076] Spline drive arm 1011 is another intermediate connection between servo 1001 and horizontal tail 111. Spline drive arm 1011 is configured to accommodate spline drive 1013. Spline drive arm 1011 includes hole 1109 ( Fig. 11C1013 is aligned with hole 1109, and spline drive arm 1013 is connected to spline drive arm 1011 via fasteners, such as Fig.12 As shown and further described below. The spline drive arm 1011 is configured to rotate, and the spline drive 1013 also rotates according to the rotation of the spline drive arm 1011. Fig.10 As shown, spline drive arm 1011 is connected to connecting rod 1000 (eg, to heim joint 1009B). As servo 1001 rotates, servo arm 1007 and connecting rod 1009 rotate, thereby causing spline drive arm 1011 and spline drive 1013 to rotate as well.

[0077] refer to Fig.10 , Fig.11A , Fig. 11B , Fig. 11C and Fig.12 , these figures are detailed views of the spline drive 1013, the shaft 803 of the horizontal tail 111, and the spline drive arm 1011 according to one embodiment. In one embodiment, the spline drive 1013 includes a first end 1101 and a second end 1103, such as Fig.11A The first end portion 1103 of the spline drive 1013 includes a plurality of mounting holes 1105. The plurality of mounting holes 1105 are, for example, threaded.

[0078] The spline drive arm 1011 includes a hole 1109 extending through the center of the spline drive arm 1011. The spline drive arm 1011 also includes a plurality of mounting holes 1111 having a smaller diameter than the hole 1109. The plurality of mounting holes 1111 of the spline drive arm 1011 are configured to align with the plurality of mounting holes on the first end of the spline drive 1013. Fasteners (e.g., bolts) 1201 are inserted through the mounting holes 1111 of the spline drive arm 1011 and the mounting holes 1105 of the spline drive 1013 to connect the spline drive arm 1011 and the spline drive 1013 together, as shown in FIG. Fig.12 shown.

[0079] In one embodiment, the spline drive 1013 includes a cavity located at the center of the spline drive 1013. The cavity includes a plurality of spline grooves (e.g., female splines) 1107, such as Fig.11A The spline groove 1107 extends from the first end 1101 of the spline drive 1013 to the second end 1103 of the spline drive 1013. In one embodiment, the spline groove 1107 tapers from the first end 1101 of the spline drive 1013 to the second end 1103 of the spline drive 1013, thereby forming a tapered shape.

[0080] refer to Fig. 11BIn one embodiment, shaft 803 of horizontal tail 111 includes a plurality of spline protrusions 1113 (e.g., male splines) at the end of shaft 803. Spline protrusions 1113 mate with spline grooves 1107 on spline drive 1107. Thus, spline protrusions 1113 taper from the base of spline protrusions 1113 to the tip of spline protrusions 1113, as shown in FIG. Fig. 11B The taper of the spline protrusion 1113 matches the taper of the spline groove 1107 .

[0081] refer to Fig.12 , shaft 803 is configured to be inserted through shaft hole 603 of boom 105 and through hole 1109 of spline drive 1011, so that spline protrusion 1113 is inserted into spline groove 1107 of spline drive 1107. Once spline protrusion 1113 contacts spline groove 1107, horizontal tail 111 is connected to horizontal tail rotation mechanism 1000 and can rotate.

[0082] Fig.13A and Fig. 13B Different views of the horizontal tail 111 in different rotational (e.g., tilted) states according to one embodiment are illustrated. As the servo 1001 rotates, the intermediate connection also rotates as described above. As the intermediate connection rotates, the shaft 803 of the horizontal tail 111 also rotates, thereby causing the horizontal tail 111 to rotate as a whole (e.g., tilt) between different angles. Therefore, the entire horizontal tail 111 rotates rather than a portion of the horizontal tail 111. In one embodiment, the horizontal tail 111 is configured to rotate up to 90 degrees from the non-rotated position of the horizontal tail 111.

[0083] As described above, each tailplane rotation mechanism 1000 is housed within a corresponding boom 105. The tailplane rotation mechanism 1000 may require maintenance and / or adjustment periodically. In one embodiment, each boom 105 includes Fig.14A 1000. Each access panel 1401 is fixed to the outer surface of the boom 105 via fasteners and is removable to access a portion of the horizontal tail 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.

[0084] In one embodiment, the first access panel 1401A is removable, and once the first access panel 1401A is removed, the connecting rod 1009 and the spline drive 1013 are exposed, such as Fig. 14BBy removing the first access panel 1401A, the length of the connecting rod 1009 can be adjusted and / or the spline drive 1013 can be inspected. In one embodiment, the second access panel 1401B is removable, and once the second access panel 1401B is removed, the servo 1001 is exposed, as shown. Fig. 14C shown.

[0085] Second embodiment of the drone structure

[0086] Fig.15 A perspective view of a drone 1500 according to another embodiment is illustrated. The drone 1500 includes similar components to the drone 100 described above. For example, the drone 1500 includes a fuselage 101, a main inner wing 102, a pylon 103, a propeller 109, a plurality of booms 105, a plurality of horizontal tails 111 (e.g., wings), and a plurality of vertical tails 107 (e.g., wings). However, compared to the drone 100, the drone 1500 includes two lower vertical tails 107B, but does not include the upper vertical tail 107A shown in the drone 100.

[0087] In this specification, reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic is included in at least one embodiment of the present disclosure. Multiple appearances of the term "in one embodiment" in this specification are not necessarily referring to the same embodiment.

[0088] While the present disclosure has been particularly shown and described with respect 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. A drone, comprising: body; a main inner wing attached to an upper surface of the fuselage, the main inner wing having a first end and a second end opposite the first end; a pylon toward a rear 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 positioned above the main inner wing; a propeller connected to the end of the pylon, the propeller being configured to generate thrust; a plurality of booms, the plurality of booms comprising a first boom and a second boom, the first boom being attached to the first end of the main inner wing and the second boom being attached to the second end of the main inner wing; and a plurality of horizontal tailplanes, the plurality of horizontal tailplanes comprising a first horizontal tailplane and a second horizontal tailplane, the first horizontal tailplane being connected to a side surface of the first boom and extending outward from the propeller, and the second horizontal tailplane being connected to a side surface of the second boom and extending outward from the propeller, Each of the plurality of horizontal tail planes is configured as a whole to rotate.

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

3. The drone of claim 1 , wherein the height of the pylon above the main inner wing is based on the diameter of the propeller. 4 . The drone of claim 3 , wherein the height of the pylon is at least 30% of the diameter of the propeller. 5 . The drone of claim 1 , wherein each of the first boom and the second boom includes a respective end located behind the rear end of the fuselage.

6. The drone of claim 5, wherein the first horizontal tail is attached to the end of the first boom behind the rear end of the fuselage, and the second horizontal tail is attached to the end of the second boom behind the rear end of the fuselage.

7. The drone according to claim 6, wherein the first length of the first boom enables the first horizontal tail to be located in an upwash airflow field where a vortex of the main inner wing is rolled up around the first boom, and the second length of the second boom enables the second horizontal tail to be located in the upwash airflow field where the vortex of the main inner wing is rolled up around the second boom.

8. The drone of claim 1, wherein the first horizontal tail comprises an anhedral angle or an dihedral angle relative to the first boom, and the second horizontal tail comprises the anhedral angle or the dihedral angle relative to the second boom.

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

10. The drone according to claim 9, wherein the drone further comprises: A plurality of horizontal tail rotation mechanisms, each horizontal tail rotation mechanism is configured to rotate a corresponding horizontal tail of the plurality of horizontal tails, the plurality of horizontal tail rotation mechanisms include a first horizontal tail rotation mechanism and a second horizontal tail rotation mechanism, the first horizontal tail rotation mechanism is located in the first boom and is configured to rotate the first horizontal tail, and the second horizontal tail rotation mechanism is located in the second boom and is configured to rotate the second horizontal tail.

11. The drone of claim 10, wherein each of the first horizontal tail rotation mechanism and the second horizontal tail rotation mechanism comprises: a mounting bracket attached to an inner surface of a corresponding boom, the mounting bracket including a cavity; a servo mechanism located in the cavity of the mount, the servo mechanism comprising an output shaft configured to rotate; a servo arm configured to rotate about the output shaft, the servo arm comprising a hole, and the output shaft of the servo mechanism is inserted into the hole of the servo arm so that the servo arm rotates as the output shaft rotates; a connecting rod having a first end and a second end, the first end of the connecting rod being connected to the servo arm such that the connecting rod is configured to rotate about the output shaft as the servo arm rotates; a spline drive arm connected to the second end of the connecting rod and including a hole, the spline drive arm being configured to rotate as the connecting rod rotates about the output shaft; and A spline drive is inserted into the hole of the spline drive arm, and the spline drive is configured to rotate as the spline drive arm rotates.

12. The drone of claim 11, wherein the spline drive comprises a cavity having a plurality of spline grooves, and each of the first shaft and the second shaft comprises a plurality of spline protrusions at the ends of the first shaft and the second shaft that match the plurality of spline grooves.

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

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

15. The drone of claim 11, wherein the servo arm further comprises a slot extending from a first end of the slot to a second end of the slot, the first end of the slot being adjacent to the hole in the servo arm, the second end of the slot being toward an end of the servo arm, The first end of the link is connected to the servo arm via the slot, and the degree of rotation of the corresponding tail wing can be adjusted based on the connection position of the first end of the link along the slot.

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

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

18. The drone of claim 1, wherein each of the first boom and the second boom comprises: a body having a first end and a second end opposite the first end; a head vertebra attached to the first end of the body; and a coccyx attached to the second end of the body, A portion of the head vertebrae and a portion of the body are connected to respective ends of the main inner wing.

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

20. The drone according to claim 6, further comprising: a first plurality of vertical tail fins connected to the end of the first boom, the first plurality of vertical tail fins comprising a first vertical tail fin and a second vertical tail fin, the first vertical tail fin extending from an upper surface of the first boom in an upward direction, the second vertical tail fin extending from a lower surface of the first boom in a downward direction, the downward direction being opposite to the upward direction; and a second plurality of vertical tail fins, the second plurality of vertical tail fins being connected to the end of the second boom, the second plurality of vertical tail fins comprising a third vertical tail fin and a fourth vertical tail fin, the third vertical tail fin extending from an upper surface of the second boom in the upward direction, the fourth vertical tail fin extending from a lower surface of the second boom in the downward direction, the downward direction being opposite to the upward direction, The first vertical tail and the third vertical tail include rudders, and the second vertical tail and the fourth vertical tail each do not include the rudder.

21. The drone according to claim 6, further comprising: a plurality of vertical tail fins, the plurality of vertical tail fins comprising a first vertical tail fin and a second vertical tail fin, The first vertical tail is attached to a lower surface of the first boom and extends from the lower surface of the first boom in a downward direction, and the second vertical tail is attached to a lower surface of the second boom and extends from the lower surface of the second boom in the downward direction.

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