Drones

Abstract

The present invention provides an unmanned aerial vehicle, comprising an unmanned aerial vehicle body and at least one rotor unit arranged on the unmanned aerial vehicle body for providing lift when the unmanned aerial vehicle takes off and lands vertically or hovers close to the ground. The unmanned aerial vehicle is characterized in that it also comprises: a noise reduction component connected to the unmanned aerial vehicle body or to the rotor unit; when the unmanned aerial vehicle flies close to the ground or a building, the noise reduction component is used to automatically extend in a direction close to and / or away from the ground and form at least one unfolding surface, all the rotor units are located on the same side of the unfolding surface, and the unfolding surface is provided with a noise reduction structure to reduce the impact of the noise generated by the rotor unit on the vicinity of the ground directly below the unmanned aerial vehicle or on people in the building.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft, and more specifically, relates to a drone with a noise reduction component. Background Art

[0002] In some application scenarios of drones' last-mile delivery and pickup, drones need to fly close to the ground or close to buildings to unload or load goods. However, due to the high noise generated by the drone's rotor unit, it is easy to cause serious noise pollution to the nearby area on the ground directly below the drone (i.e. the area diagonally below the drone) or people in the building. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a drone to solve the problem in the related art that the noise generated by the drone when flying close to the ground or close to a building will cause serious noise pollution to people.

[0004] To achieve the above-mentioned purpose, the present invention provides a drone, comprising: a drone body and at least one rotor unit arranged on the drone body for providing lift when the drone takes off and lands vertically or hovers close to the ground, and also comprising: a noise reduction component connected to the drone body or to the rotor unit; when the drone flies close to the ground or a building, the noise reduction component is used to automatically extend in a direction close to and / or away from the ground and form at least one unfolding surface, all of the rotor units are located on the same side of the unfolding surface, and the unfolding surface is provided with a noise reduction structure to reduce the impact of the noise generated by the rotor unit on the vicinity of the ground directly below the drone or on people in the building.

[0005] In one embodiment, the noise reduction component includes a panel that can be folded and retracted and a driving mechanism that drives the panel to extend and / or contract, and the panel is provided with a plurality of folding marks or hinge axes perpendicular to its retracting direction; after the panel is fully extended, the panel can enclose all the blades of the rotor unit, and the inner surface of the panel facing the rotor unit forms the annular unfolded surface.

[0006] In one embodiment, the noise reduction assembly further comprises a top frame connected to the top edge of the panel and a bottom frame connected to the bottom edge, and the driving mechanism comprises at least two groups of driving units respectively arranged at the front and rear sides of the drone or respectively arranged at the left and right sides of the drone;

[0007] Each group of the driving units includes an active strut rotatably connected to the drone body or the rotor unit, and a driving motor arranged on the drone body or the rotor unit or the active strut and used to drive the active strut to rotate relative to the drone body or the rotor unit. The two ends of the active strut are respectively slidably connected to the top frame and the bottom frame. The top frame and the bottom frame are respectively moved in two directions away from and close to the ground through the rotation of the active strut relative to the drone body or the rotor unit, thereby realizing the extension and / or contraction of the panel; or, the noise reduction component also includes an installation body located between the top frame and the bottom frame. The mounting seat and / or the UAV also includes a protective frame connected to the UAV body or the rotor unit, and each group of the driving units includes a movable strut rotatably connected to the mounting seat and / or the protective frame, and a driving motor provided on the mounting seat or the protective frame or the movable strut and used to drive the movable strut to rotate relative to the mounting seat and / or the protective frame. The two ends of the movable strut are respectively slidably connected to the top frame and the bottom frame, and the top frame and the bottom frame are respectively moved in two directions away from and close to the ground through the rotation of the movable strut relative to the mounting seat and / or the protective frame, thereby realizing the extension and / or contraction of the panel.

[0008] In one embodiment, the noise reduction assembly further comprises a top frame connected to the top edge of the panel and a bottom frame connected to the bottom edge;

[0009] After the panel is fully retracted, the top frame and the bottom frame together form a storage space for accommodating the panel; or, the noise reduction component is further provided with a mounting base located between the top frame and the bottom frame, and after the panel is fully retracted, the top frame, the bottom frame and the mounting base together form a storage space for accommodating the panel; or, the noise reduction component also includes a mounting base located between the top frame and the bottom frame and / or the drone also includes a protective frame connected to the drone body or the rotor unit, and after the panel is fully retracted, the top frame, the bottom frame, the protective frame and / or the mounting frame together form a storage space for accommodating the panel.

[0010] In one embodiment, the UAV further includes a protective frame connected to the UAV body or the rotor unit, the main body of the protective frame is an annular frame and encloses all the blades of the rotor unit, and the panel can be mounted on the protective frame to facilitate the installation and removal of the noise reduction component from the UAV.

[0011] In one embodiment, the drone further comprises a protective frame connected to the drone body or the rotor unit, all the rotor units are located on the same side of the protective frame, and the noise reduction component is arranged on the protective frame;

[0012] The noise reduction component includes at least one rolling curtain mechanism, wherein the rolling curtain mechanism includes a rolling curtain and a scroll shaft, the scroll shaft is rotatably connected to the protective frame, the rolling curtain is provided with the noise reduction structure and can be rolled up around the scroll shaft, one end of the rolling curtain is connected to the scroll shaft, and the other end is provided with a strip rod, the protective frame is provided with at least two extensions extending downwardly and spaced apart from each other, the rolling curtain mechanism is located between the two extensions, and the two ends of the strip rod on the rolling curtain mechanism are respectively slidably connected to the two extensions, so that the strip rod can slide downwardly of the drone and away from the scroll shaft, thereby realizing the unfolding of the rolling curtain and forming the The unfolding surface; or, the noise reduction component includes at least one foldable and retractable panel, wherein the panel is provided with the noise reduction structure and a plurality of folding marks or hinge axes perpendicular to the retracting direction thereof, one edge of the panel is connected to the protective frame, and the other edge away from the protective frame is provided with a strip bar, the protective frame is provided with at least two extension parts extending downwardly and spaced apart from each other, the panel is located between the two extension parts and the two ends of the strip bar on the panel are respectively slidably connected with the two extension parts, so that the strip bar can slide downwardly of the drone and away from the protective frame, thereby realizing the unfolding of the panel and forming the unfolding surface.

[0013] In one embodiment, the extension portion is a landing gear of the drone, which is used to support the weight of the drone after the drone lands.

[0014] In one embodiment, the noise reduction component further comprises:

[0015] a movable plate and a driver, wherein the movable plate is movably connected to the strip rod, and the driver is used to drive the movable plate to move relative to the strip rod, so that the force of the downwash airflow of the rotor unit on the movable plate is increased to drive the strip rod away from the reel; and

[0016] An elastic member is used for providing elastic torque to drive the strip rod to approach the reel.

[0017] In one embodiment, the noise reduction component further comprises:

[0018] A movable plate and a driver, wherein the driver is used to drive the movable plate to move so that the force of the downwash airflow of the rotor unit on the movable plate is increased to drive the noise reduction component to extend and form the deployment surface.

[0019] In one embodiment, the movable plate is provided with a noise reduction structure, and the movable plate is also used to reduce the diffraction of the noise generated by the rotor unit relative to the noise reduction component;

[0020] And / or, the movable plate is a flat plate, and during the process of the movable plate moving toward the side where the rotor unit is located, a fold angle in the range of 100 degrees to 170 degrees is finally formed between a surface of the movable plate opposite to the rotor unit and the unfolded surface of the noise reduction component.

[0021] In one embodiment, the UAV includes a flight controller and a sensor for measuring wind speed or wind strength, and the flight controller is electrically connected to the sensor to measure wind speed or wind strength; when the UAV flies close to the ground, if the measured wind speed or wind strength is too large, the flight controller can control the noise reduction component to stop extending and keep the noise reduction component in a retracted state.

[0022] The beneficial effect of the drone provided by the present invention is that by arranging a noise reduction component, the drone can reduce the impact of the noise generated by the rotor unit on the nearby area on the ground directly below the drone or on people in the building when flying close to the ground or close to a building, and because the noise reduction component is only extended and forms an unfolded surface when the drone flies close to the ground or close to a building, it avoids the larger side area of ​​the noise reduction component after extension during the drone cruising flight, which leads to a significant increase in the aerodynamic resistance of the drone and a significant increase in lateral interference of the drone by strong winds. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or exemplary technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A three-dimensional schematic diagram of a drone provided by an embodiment of the present application with the noise reduction component in an extended state;

[0025] Figure 2 for Figure 1 A three-dimensional schematic diagram of a drone approaching the top of a storage and retrieval terminal;

[0026] Figure 3 for Figure 1 The three-dimensional schematic diagram of the drone shown is in a state where the noise reduction components are folded;

[0027] Figure 4 A three-dimensional schematic diagram of a rolling curtain mechanism provided in an embodiment of the present application in an extended state;

[0028] Figure 5 for Figure 4 A three-dimensional schematic diagram of the rolling curtain mechanism in a folded state is shown;

[0029] Figure 6 A three-dimensional schematic diagram of a foldable and retractable panel in a folded state provided by another embodiment of the present application;

[0030] Figure 7 for Figure 6 The enlarged schematic diagram of point A in the middle;

[0031] Figure 8 A three-dimensional schematic diagram of a drone provided by another embodiment of the present application with the noise reduction component in an extended state;

[0032] Fig. 9 for Figure 8 A three-dimensional schematic diagram of the noise reduction component in the state shown;

[0033] Fig.10 For this application Figure 8 The three-dimensional schematic diagram of the drone shown is in a state where the noise reduction components are folded;

[0034] Fig.11 for Fig.10 A three-dimensional schematic diagram of the noise reduction component in the illustrated state. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0037] In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0038] In the description of the present application, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0039] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] Reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, when the phrases "in one embodiment" or "in some embodiments" appear in various places throughout the specification, not all references are to the same embodiment. Furthermore, in one or more embodiments, the particular features, structures, or characteristics may be combined in any suitable manner.

[0041] See also Figures 1 to 3, the drone 10 provided by the present application is now described. The drone 10 includes a drone body 110 and at least one rotor unit 120 provided on the drone body 110 for providing lift when the drone 10 takes off and lands, or more precisely, the rotor unit 120 is used to provide lift when the drone 10 takes off and lands vertically or hovers close to the ground. Specifically, the rotor unit 120 includes blades, a motor for driving the blades to rotate, and a motor arm or motor mounting seat that fixes the motor and is connected to the drone body 110. The drone 10 also includes a protective frame 130 connected to the drone body 110 or the rotor unit 120, wherein the protective frame 130 is used to prevent the rotor unit 120 from contacting with foreign objects or reduce the intensity of the collision between the rotor unit 120 and foreign objects, thereby playing a certain protective role on the rotor unit 120 or foreign objects, and all the rotor units 120 are located on the same side of the protective frame 130. A noise reduction component 140 is provided on the protective frame 130. When the drone 10 flies close to the ground, for example, when the drone 10 descends to the top of the storage and retrieval terminal 20 or takes off from the top of the storage and retrieval terminal 20, the noise reduction component 140 can automatically extend in the direction close to the ground and form at least one unfolding surface, wherein the unfolding surface is opposite to the rotor unit 120 and at least part of the unfolding surface is lower than the blades of the rotor unit 120; the unfolding surface is provided with a noise reduction structure to reduce the impact of the noise generated by the rotor unit 120 on people in the vicinity of the ground directly below the drone 10 (i.e., the area diagonally below the drone 10). Specifically, the noise reduction structure can be a sound-absorbing structure, such as sound-absorbing felt, sound-absorbing board and other sound-absorbing materials or sound-absorbing coatings; or the noise reduction structure can also be a sound insulation structure, such as sound insulation felt, sound insulation board and other sound insulation materials or sound insulation coatings; or the noise reduction structure can also be a material or coating that can effectively reflect sound, such as a material with a relatively hard texture. Correspondingly, the unfolded surface can be inclined at a certain angle or form a certain arc relative to the height direction or vertical direction of the drone 10 to reflect part of the noise generated by the rotor unit 120 to a direction or area away from the personnel; or the noise reduction structure can also be an airflow regulating structure that can improve the airflow near or upstream and downstream of the blades of the rotor unit 120, thereby reducing the noise generated by the interaction between the blades and the airflow. By providing the noise reduction component 140, the drone 10 can reduce noise pollution to the vicinity of the ground directly below it when flying close to the ground. In addition, since the noise reduction component 140 is extended and forms an unfolded surface only when the drone 10 flies close to the ground, the larger side area of ​​the noise reduction component 140 after extension during the cruising flight of the drone 10 causes a significant increase in the aerodynamic resistance of the drone 10 and a significant increase in lateral interference to the drone 10 caused by strong winds. This helps to reduce the negative impact of the noise reduction component 140 on the flight efficiency and flight stability of the drone 10, and also helps to extend the service life of the noise reduction component.

[0042] In the illustrated embodiment, the drone 10 adopts a conventional quad-rotor aircraft layout, that is, the drone 10 includes four rotor units 120; the main body of the protective frame 130 connected to the drone body 110 is an annular frame and encloses all the blades of the rotor units 120, that is, the blades of the four rotor units 120 are all located on the inner side of the protective frame 130; the number of noise reduction components 140 is four, and the four noise reduction components 140 are respectively arranged on the front side, rear side, left side and right side of the rotor unit 120 and are all located on the inner side of the main body of the protective frame 130. When the drone 10 flies close to the ground, the four noise reduction components 140 can automatically extend in the direction close to the ground and form four unfolding surfaces. The four unfolding surfaces jointly enclose the rotor unit 120 and the space directly below the rotor unit 120 and within a certain distance from the rotor unit 120. The sound barrier thus formed can reduce the impact of the noise generated by the rotor unit 120 on people in the surrounding area close to the ground directly below the drone 10. Moreover, the channel formed by the four unfolded surfaces also has a function similar to a duct, which can increase the lift of the drone 10, so that the rotor unit 120 can obtain the lift required by the drone 10 at a lower blade speed, thereby reducing the noise generated by the blades, especially the wing tips of the blades, and the airflow. It should be noted that the number of rotor units 120 of the drone 10 is not limited to four, and the main body of the protective frame 130 is not limited to a ring shape. For example, in other embodiments of the present embodiment, the main body of the protective frame 130 is a strip structure and is arranged on the front side of the rotor unit 120. A noise reduction component 140 is arranged on the main body of the protective frame 130. When the drone 10 flies close to the ground, the noise reduction component 140 can only reduce the noise generated by the rotor unit 120 on the personnel in the front area close to the ground directly below the drone 10 after being extended. In addition, the protective frame 130 may also be provided with a noise reduction structure to further reduce the impact of the noise generated by the rotor unit 120 on the vicinity of the ground directly below the drone 10. For example, when the main body of the protective frame 130 is an annular frame and the noise reduction component 140 is disposed on the outside or bottom of the main body of the protective frame 130, the surface of the main body of the protective frame 130 that is opposite to or adjacent to the blades of the rotor unit 120 may be provided with a noise reduction structure.

[0043] In other embodiments, the UAV 10 may also adopt a hybrid lift aircraft layout combining fixed wings and rotors, so in addition to the rotor unit 120, the UAV 10 may also include a rotor unit that only provides thrust for the UAV 10 to fly forward. When the UAV 10 flies close to the ground, that is, when the UAV 10 takes off and lands vertically or hovers close to the ground, the rotor unit is in a state of stopped rotation or low speed and does not provide lift or generate noise pollution. Therefore, the rotor unit can be located on any side of the protective frame 130 relative to the rotor unit 120. It should be noted that at this time, the wings of the UAV 10 can be regarded as part of the UAV body 110.

[0044] Please also read Figure 4 and 5 As a specific embodiment of the noise reduction component 140, a noise reduction component 140 includes at least one rolling curtain mechanism, wherein the rolling curtain mechanism further includes a rolling curtain 141 and a reel 142. The reel 142 is rotatably connected to the protective frame 130. In the illustrated embodiment, the main body of the protective frame 130 is an annular frame and is roughly in the shape of a regular quadrilateral. The two ends of a reel 142 are respectively connected to two adjacent corners of the main body of the protective frame 130. The rolling curtain 141 is provided with a noise reduction structure and can be rolled up around the reel 142. One end of the rolling curtain 141 is connected to the reel 142, and the other end is provided with a strip rod 143. The protective frame 130 is also provided with at least two extensions 1301 extending downward and spaced apart from each other from the drone 10. Optionally, the extensions 1301 can be used as landing gears of the drone 10 to support the weight of the drone 10 after the drone 10 lands. Of course, the drone body 110 or the rotor unit 120 can also be provided with landing gears. A rolling curtain mechanism is located between the two extensions 1301, and the two ends of the bar 143 on the rolling curtain mechanism are respectively slidably connected to the two extensions 1301 located on both sides thereof, so that the bar 143 can slide toward the bottom of the drone 10 and away from the reel 142, thereby realizing the unfolding of the rolling curtain 141 and forming the above-mentioned unfolding surface. Optionally, the extension 1301 is provided with a slide groove 13011 extending along its length direction, and the two ends of the bar 143 extend into the slide grooves 13011 of the two extensions 1301 located on both sides thereof and can slide along the slide grooves 13011. It can be understood that the reel 142 can also be indirectly connected to the protective frame 130 through a connecting structure (not shown), that is, connecting structures are set at both ends of the reel 142 and the reel 142 is rotatably connected to the connecting structure, and the connecting structure can also be detachably connected to the protective frame 130, for example, using a snap-on quick-release connection method, so as to facilitate the rapid disassembly and assembly of the noise reduction component 140 on the protective frame 130.

[0045] Optionally, the noise reduction component 140 also includes a movable plate 144 and a driver 145. The movable plate 144 is movably connected to the strip rod 143. When the drone 10 flies close to the ground, the movable plate 144 is lower than the blades of the rotor unit 120 and the driver 145 can drive the movable plate 144 to move relative to the strip rod 143, so that the movable plate 144 is at least partially located in the downwash airflow of the rotor unit 120 and the force of the downwash airflow of the rotor unit 120 is greatly increased, thereby driving the strip rod 143 away from the reel 142, wherein the driver 145 can be a small servo. In one embodiment of the present embodiment, the movable plate 144 is a long flat plate, and the length dimension of the movable plate 144 is much larger than the width dimension, wherein a long edge of the movable plate 144 is hinged to the strip rod 143, and its hinge axis is parallel to the length direction of the strip rod 143. When the drone 10 flies close to the ground, please refer to Figure 1 and Figure 4 , the driver 145 drives the movable plate 144 to deflect relative to the strip rod 143 toward the side where the rotor unit 120 is located, so that the impact force of the downwash airflow of the rotor unit 120 on the side of the movable plate 144 opposite to the rotor unit 120 is greatly increased, so that the movable plate 144 begins to move toward the bottom of the drone 10 and drives the strip rod 143 away from the reel 142, conversely, the driver 145 drives the movable plate 144 to deflect relative to the strip rod 143 toward the side away from the rotor unit 120 so that the impact force of the downwash airflow of the rotor unit 120 on the movable plate 144 is greatly reduced; in another implementation manner of the present embodiment, the movable plate 144 is slidably connected to the strip rod 143, and the driver 145 can drive the movable plate 144 to slide relative to the strip rod 143 toward the side where the rotor unit 120 is located and toward the side away from the rotor unit 120, respectively, so as to adjust the force of the downwash airflow of the rotor unit 120 on the movable plate 144. In addition, the noise reduction assembly 140 further includes an elastic member (not shown), which is disposed between the reel 142 and the protective frame 130 or the connecting structure and is used to provide an elastic torque to drive the reel 142 to rotate and drive the bar 143 to approach the reel 142, thereby realizing the folding of the roller blind 141, wherein the elastic member may be a torsion spring connecting the reel 142 and the protective frame 130 or the connecting structure. When the roller blind 141 is fully folded, as shown in FIG. Figure 5 As shown, the strip bar 143 and the movable plate 144 are both close to the reel 142, thereby minimizing the side area of ​​the noise reduction assembly 140, and the folded noise reduction assembly 140 can also at least partially overlap with the main body of the protection frame 130 to reduce the overall side area of ​​the noise reduction assembly 140 and the protection frame 130. The extension and folding of the noise reduction assembly 140 are driven by the movable plate 144 and the elastic member, and the related mechanism is simple, which helps to reduce the overall weight of the noise reduction assembly 140 and improve the reliability of the operation of the noise reduction assembly 140.

[0046] Furthermore, the movable plate 144 is also provided with a noise reduction structure. Specifically, when the movable plate 144 moves relative to the bar 143 toward the side where the rotor unit 120 is located, the side of the movable plate 144 opposite to the rotor unit 120 is provided with a noise reduction structure, thereby further reducing the impact of the noise generated by the rotor unit 120 on the area near the ground directly below the drone 10. In addition, please refer to Figure 1 and Figure 4 When the movable plate 144 is a flat plate and moves toward the side where the rotor unit 120 is located, a fold angle greater than 0 degrees and less than 180 degrees is finally formed between the surface of the movable plate 144 opposite to the rotor unit 120 and the unfolded surface of the noise reduction component 140. Preferably, the fold angle is selected within the range of 100 degrees to 170 degrees, thereby also reducing the diffraction of the noise generated by the rotor unit 120 relative to the noise reduction component 140; optionally, the movable plate 144 may also be an arc-shaped panel, and can also reduce the diffraction of the noise generated by the rotor unit 120 relative to the noise reduction component 140.

[0047] It should be noted that the noise reduction component 140 may also not include the movable plate 144. In other implementations of the present embodiment, the roller blind 141 is a hard roller blind 141, and the driver (not shown) is used to drive the reel 142 to rotate in both directions so that the strip rod 143 moves away from and approaches the reel 142; or, the roller blind 141 is a soft roller blind 141, and the driver is used to drive the reel 142 to rotate so that the roller blind 141 is rolled up around the reel 142 and the strip rod 143 moves closer to the reel 142. The elastic member (not shown) is provided between the strip rod 143 and one end of the extension portion 1301 away from the protective frame 130, and is used to provide an elastic force so that the strip rod 143 can move away from the reel 142. Optionally, the elastic member is a linear spring and connects the strip rod 143 and one end of the extension portion 1301 away from the protective frame 130.

[0048] Further, in one implementation of the present embodiment, the drone 10 further includes a flight controller and a distance sensor such as a laser rangefinder for measuring the distance between the drone 10 and the ground, and the flight controller is also electrically connected to the distance sensor and the driver of the noise reduction component 140 to read the data of the distance sensor and control the driver to work. When the drone 10 flies close to the ground, the flight controller can control the driver of the noise reduction component 140 to work so that the noise reduction component 140 extends in a direction close to the ground. Alternatively, the drone 10 may not include a flight controller and a distance sensor. For example, in another implementation of the present embodiment, the drone 10 includes a wireless communication module, which is electrically connected to the driver of the noise reduction component 140. When the drone 10 flies close to the ground, the wireless communication module can receive remote control instructions and control the driver of the noise reduction component 140 to work so that the noise reduction component 140 extends in a direction close to the ground.

[0049] Further, in one implementation of the present embodiment, the drone 10 includes a flight controller and a sensor for measuring wind speed or wind strength. Optionally, the sensor includes at least one of a global navigation satellite system (GNSS) receiving device and an inertia measurement unit (IMU). The flight controller is electrically connected to the above sensor to measure the wind speed or wind strength. For example, the real-time attitude and position data of the drone 10 measured by the above sensor can roughly measure the wind speed or wind strength. When the drone 10 flies close to the ground, if the measured wind speed or wind strength is too large, the flight controller can control the noise reduction component 140 to stop extending and keep the noise reduction component 140 in a folded state to avoid a significant increase in the lateral interference of the strong wind to the drone 10. In other implementations, the flight controller can also provide the measured wind speed or related information to the module that controls the driver of the noise reduction component 140 to achieve the noise reduction component 140 Keep the folded state.

[0050] It should be noted that, in addition to the rolling curtain mechanism, the noise reduction component 140 can also use other mechanisms or structures to achieve extension and retraction, and when the noise reduction component 140 uses other mechanisms or structures, the extension and retraction of the noise reduction component 140 can also be driven by the movable plate 144 and the elastic member, that is, when the drone 10 flies close to the ground, the driver is used to drive the movable plate 144 to move, so that the force of the downwash airflow of the rotor unit 120 on the movable plate 144 increases and drives the noise reduction component 140 to extend and form an unfolded surface, and the elastic member is used to provide elastic torque or elastic force to drive the noise reduction component 140 to retract so as to reduce the side area of ​​the noise reduction component 140 when the drone 10 is cruising. Alternatively, the elastic member can also be omitted, that is, the noise reduction component 140 is manually retracted after the drone 10 lands, and the movable plate 144 drives the noise reduction component 140 to extend and form an unfolded surface before the next landing of the drone 10.

[0051] The structure of the drone provided in another embodiment of the present application is basically the same as that of the drone 10 provided with the movable plate 144 in the above embodiment. The difference is that, please refer to Figure 6 and Figure 7, the rolling curtain 141 and the rolling shaft 142 of the noise reduction component 140 are replaced with a foldable and retractable panel 146, that is, a noise reduction component 140 includes at least one foldable and retractable panel 146, wherein the panel 146 is provided with a plurality of folding marks or hinge axes perpendicular to the retracting direction thereof, one edge of the panel 146 is connected to the main body of the protective frame 130, and the other edge away from the main body of the protective frame 130 is provided with a strip rod 143, and the movable plate 144 is movably connected to the strip rod 143; the panel 146 is arranged between the two extensions 1301 of the protective frame 130, and the two ends of the strip rod 143 on the panel 146 are respectively slidably connected to the two extensions 1301 located on both sides thereof, so that the strip rod 143 can slide to the bottom of the UAV and away from the main body of the protective frame 130 under the drive of the movable plate 144, so that the panel 146 is unfolded and forms an unfolding surface, and the panel 146 is also provided with a noise reduction structure to reduce the influence of the noise generated by the rotor unit 120 on the vicinity of the ground directly below the UAV 10. The elastic member (not shown) is disposed between the strip rod 143 and the main body of the protective frame 130 or the edge where the panel 146 is connected to the main body of the protective frame 130 and is used to provide elastic force so that the strip rod 143 can be close to the main body of the protective frame 130, thereby driving the panel 146 to fold and gather to reduce the side area of ​​the noise reduction assembly 140. Optionally, the elastic member is a linear spring and connects the strip rod 143 and the main body of the protective frame 130 or the edge where the panel 146 is connected to the main body of the protective frame 130. It is easy to understand that when the panel 146 is hinged by a plurality of hard plates, the strip rod 143 can also be omitted, that is, the edge of the panel 146 away from the main body of the protective frame 130 is directly slidably connected to the two extensions 1301 on both sides, and at this time, the movable plate 144 is directly and movably connected to the edge of the panel 146 away from the main body of the protective frame 130.

[0052] Alternatively, the noise reduction component of the drone 10 can also automatically extend in a direction away from the ground to reduce the impact of the noise generated by the rotor unit 120 on more areas including the area obliquely above the drone 10. For example, a platform for the drone 10 to land and load and unload goods is set outside the balcony or window sill of one floor of a high-rise apartment. When the drone 10 flies close to the platform, the noise reduction component can automatically extend in two directions close to and away from the ground to reduce the impact of the noise generated by the rotor unit 120 on the floor where the platform is located and the upper and lower adjacent floors. Optionally, two noise reduction components located on the same side of the rotor unit 120 are arranged up and down and can automatically extend in two directions away from and close to the ground respectively, or a noise reduction component located on the same side of the rotor unit 120 can automatically extend in two directions close to and away from the ground at the same time; or a noise reduction component located on the same side of the rotor unit 120 can automatically extend in a direction away from the ground.

[0053] Thus, when the drone 10 flies close to the ground or close to a building, the noise reduction component is used to automatically extend in a direction close to and / or away from the ground and form at least one unfolding surface, and all the rotor units 120 are located on the same side of the unfolding surface, and the unfolding surface is provided with a noise reduction structure to reduce the impact of the noise generated by the rotor unit 120 on the nearby area of ​​the ground directly below the drone 10 or on the personnel in the building. Among them, the protective frame 130 can be omitted, that is, the noise reduction component can be directly or indirectly connected to the drone body or the rotor unit 120.

[0054] In another embodiment of the present application, please refer to Figures 8 to 11The main body of the protection frame 130' is an annular frame and encloses all the blades of the rotor unit 120. The noise reduction component 140' includes a panel 1410 that can be folded and extended and a driving mechanism that drives the panel 1410 to extend and / or contract. The panel 1410 is also provided with a plurality of folding marks or hinge axes perpendicular to its extension direction and can be sleeved on the protection frame 130'. After the panel 1410 is fully extended, the panel 1410 can enclose all the blades of the rotor unit 120, and the inner surface of the panel 1410 facing the rotor unit 120 forms an annular unfolding surface, so as to reduce the impact of the noise generated by the rotor unit 120 on the people in the building when the drone 10' flies close to the building, or to reduce the impact of the noise generated by the rotor unit 120 on the people in the vicinity of the ground directly below the drone 10' when the drone 10' flies close to the ground. The top edge of the fully extended panel 1410 may be significantly higher than the blades of the rotor unit 120 of the drone 10', and the bottom edge of the fully extended panel 1410 may be significantly lower than the blades of the rotor unit 120 of the drone 10'. Specifically, the panel 1410 is provided with a noise reduction structure, and the noise reduction component 140' further includes a top frame 1411 connected to the top edge of the panel 1410 and a bottom frame 1412 connected to the bottom edge of the panel 1410, and a mounting seat 1413 located between the top frame 1411 and the bottom frame 1412, wherein the mounting seat 1413 can be fixedly connected to the protective frame 130', more specifically, the mounting seat 1413 can be detachably connected to the protective frame 130', for example, by a snap-on quick-release connection, the driving mechanism includes at least two groups of driving units respectively arranged on the front and rear sides of the drone 10' or respectively arranged on the left and right sides of the drone 10', wherein each group of driving units includes a movable strut 1414 rotatably connected to the mounting seat 1413 and a driving motor arranged on the mounting seat 1413 or the movable strut 1414 and used to drive the movable strut 1414 to rotate relative to the mounting seat 1413, The two ends of the movable strut 1414 are respectively slidably connected to the top frame 1411 and the bottom frame 1412, and the top frame 1411 and the bottom frame 1412 are respectively moved in two directions away from and close to the ground by rotating the movable strut 1414 relative to the mounting seat 1413, thereby realizing the extension and / or contraction of the panel 1410. Moreover, after the panel 1410 is fully extended, the movable strut 1414 can also provide support for the panel 1410, especially the part of the panel 1410 that is higher than the protective frame 130', to prevent the panel 1410, especially the part of the panel 1410 that is higher than the protective frame 130', from being greatly deformed or shaken. It should be noted that the driving motor can directly drive or indirectly drive the movable strut 1414 to rotate relative to the mounting seat 1413 through a transmission mechanism; a part of the fully extended panel 1410 can be directly mounted on the main body or extension portion of the protective frame 130', such as Figure 8As shown, the protective frame 130' can be effectively supported and is less likely to deform or shake significantly. Of course, there may be a gap between the inner surface of the panel 1410 and the protective frame 130'. After the panel 1410 is fully retracted, the movable struts 1414 of each group of drive units are tilted at a large angle relative to the height direction of the drone 10', and the top frame 1411 and the bottom frame 1412 are close to the mounting seat 1413 to minimize the distance between the top frame 1411 and the bottom frame 1412. At this time, the panel 1410 is compressed between the top frame 1411 and the bottom frame 1412, thereby greatly reducing the side area of ​​the noise reduction component 140'. The panel 1410 of the noise reduction component 140' in this embodiment can be only set on the periphery of the protective frame 130', without the need to set up additional related structures on the drone 10' for realizing the active connection between the extended end of the panel 1410 and the protective frame 130'. For example, the drone 10' does not need to set up a bar and a slide groove for the two ends of the bar to extend into, so as to facilitate the installation and removal of the noise reduction component 140' from the drone 10'. In addition, the channel formed by the fully extended panel 1410 also has a duct-like function, which can increase the lift of the drone 10', so that the rotor unit 120 can obtain the lift required by the drone 10' at a lower blade speed, thereby reducing the noise generated by the blade, especially the wing tip of the blade, and the airflow.

[0055] Furthermore, after the panel 1410 is fully retracted, the top frame 1411 and the bottom frame 1412 can also be combined to form a storage space for accommodating the panel 1410 to avoid exposure of the panel 1410, which helps to extend the service life of the panel 1410 and further reduce the negative impact of the noise reduction component 140' on the flight efficiency and flight stability of the drone 10'. For example, the top frame 1411 is provided with a groove or a concave surface opposite to the bottom frame 1412, and / or the bottom frame 1412 can also be provided with a groove or a concave surface opposite to the top frame 1411. After the panel 1410 is fully retracted, the top frame 1411 is combined with the bottom frame 1412, and the panel 1410 is stored in the storage space formed by the above-mentioned groove or concave surface. Alternatively, after the panel 1410 is completely retracted, the top frame 1411, the bottom frame 1412, the protection frame 130' and / or the mounting seat 1413 may be combined to form a storage space for accommodating the panel 1410, for example, see Fig.10 and Fig.11, the top frame 1411 and the bottom frame 1412 are both provided with flanges located on the outside of the panel 1410. After the panel 1410 is fully retracted, the flange of the top frame 1411 is combined with the flange of the bottom frame 1412 to enclose the fully retracted panel 1410. At the same time, the remaining parts of the top frame 1411 and the remaining parts of the bottom frame 1412 are respectively located on the upper and lower sides of the panel 1410, and the main body or mounting seat 1413 of the protective frame 130' is located on the inner side of the panel 1410.

[0056] It should be noted that the mounting seat 1413 can be an annular frame, and can be mounted on the protective frame 130' when installed on the protective frame 130'. Of course, the mounting seat 1413 can also be other structures, and the structure of the mounting seat 1413 is not solely limited here. For example, the mounting seat 1413 is a strip rod respectively arranged on the front and rear sides of the drone 10' or respectively arranged on the left and right sides of the drone 10'. It is easy to understand that the main body of the protective frame 130' can also be other structures, and the structure of the protective frame 130' is not solely limited here, and the different movable struts 1414 in the drive unit can also be respectively arranged on the mounting seat 1413 and the protective frame 130'. It should be noted that the mounting base 1413 may also be omitted. In this case, the movable support rod 1414 may be directly rotatably connected to the protective frame 130', and the driving motor that drives the movable support rod 1414 to rotate relative to the protective frame 130' may be provided on the movable support rod 1414 or the protective frame 130'; or, in another embodiment, one end of the movable support rod 1414 is rotatably connected to the bottom frame 1412, and the other end is slidably connected to the top frame 1411, and the bottom frame 1412 may be fixedly connected to the extension portion 1301' of the protective frame 130' and A driving motor is provided to drive the movable strut 1414 to rotate relative to the bottom frame 1412. The top frame 1411 is moved away from the ground to move away from the bottom frame 1412 by the rotation of the movable strut 1414 relative to the bottom frame 1412, thereby realizing the extension and / or contraction of the panel 1410. Of course, in other embodiments, the top frame 1411 may be fixedly connected to the main body of the protective frame 130', and the bottom frame 1412 may move relative to the top frame 1411 in a direction close to the ground to move away from the top frame 1411. Alternatively, the driving mechanism may also adopt other structures, and the structure of the driving mechanism is not limited here. For example, the driving mechanism may be a telescopic rod or a movable rod connecting the top frame 1411 and the protective frame 130', or a telescopic rod or a movable rod connecting the bottom frame 1412 and the protective frame 130', or a telescopic rod or a movable rod connecting the top frame 1411 and the bottom frame 1412.

[0057] Furthermore, the protective frame 130' can be disassembled from the drone body 110 or the rotor unit 120 of the drone 10' together with the noise reduction component 140', or the protective frame 130' can also be omitted. In this case, the noise reduction component 140' can be directly connected to the drone body 110 or the rotor unit 120. In one embodiment, the mounting seat 1413 is fixedly connected to the drone body 110 or the rotor unit 120, or the movable strut 1414 can be directly rotatably connected to the drone body 110 or the rotor unit 120, driving the movable strut 1414 to rotate relative to the drone body 110 or the rotor unit 120. The driving motor of the movable support rod 1414 can be arranged on the movable support rod 1414 or the drone body 110 or the rotor unit 120, wherein if the movable support rod 1414 is directly rotatably connected to the rotor unit 120, the rotor unit 120 can be provided with a protrusion with one end away from the motor, and the movable support rod 1414 is directly rotatably connected to the end of the protrusion away from the motor, so that the noise reduction component 140' is spaced from the blades of the rotor unit 120. In addition, if the protective frame 130' and the mounting frame 1413 are omitted, the top frame 1411 or the bottom frame 1412 can also be directly fixedly connected to the drone body 110 or the rotor unit 120. It can be understood that after the panel 1410 is fully retracted, the top frame 1411 and / or the bottom frame 1412 of the noise reduction component 140' can also be used to replace the protective frame 130' to provide a certain protection for the blades of the rotor unit 120.

[0058] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A drone, comprising a drone body and at least one rotor unit provided on the drone body for providing lift when the drone takes off and lands vertically or hovers close to the ground, characterized in that: The UAV further includes: a noise reduction component connected to the UAV body or to the rotor unit; the noise reduction component can be folded to reduce the side area of ​​the noise reduction component when the UAV is cruising; when the UAV flies close to the ground or a building, the noise reduction component is used to automatically extend in a direction close to and / or away from the ground and form at least one unfolding surface, all of the rotor units are located on the same side of the unfolding surface, and the unfolding surface is provided with a noise reduction structure to reduce the impact of the noise generated by the rotor unit on the nearby area on the ground directly below the UAV or on people in the building.

2. The drone according to claim 1, characterized in that: The noise reduction component includes a foldable and retractable panel and a driving mechanism for driving the panel to extend and / or contract; after the panel is fully extended, the panel can enclose all the blades of the rotor unit, and the inner surface of the panel facing the rotor unit forms the annular unfolded surface.

3. The drone according to claim 2, characterized in that: The noise reduction assembly further includes a top frame connected to the top edge of the panel and a bottom frame connected to the bottom edge, and the driving mechanism includes at least two groups of driving units respectively arranged at the front and rear sides of the drone or respectively arranged at the left and right sides of the drone; Each group of the driving units includes an active strut rotatably connected to the drone body or the rotor unit, and a driving motor arranged on the drone body or the rotor unit or the active strut and used to drive the active strut to rotate relative to the drone body or the rotor unit. The two ends of the active strut are respectively slidably connected to the top frame and the bottom frame. The top frame and the bottom frame are respectively moved in two directions away from and close to the ground through the rotation of the active strut relative to the drone body or the rotor unit, thereby realizing the extension and / or contraction of the panel; or, the noise reduction component also includes an installation body located between the top frame and the bottom frame. The mounting seat and / or the UAV also includes a protective frame connected to the UAV body or the rotor unit, and each group of the driving units includes a movable strut rotatably connected to the mounting seat and / or the protective frame, and a driving motor provided on the mounting seat or the protective frame or the movable strut and used to drive the movable strut to rotate relative to the mounting seat and / or the protective frame. The two ends of the movable strut are respectively slidably connected to the top frame and the bottom frame, and the top frame and the bottom frame are respectively moved in two directions away from and close to the ground through the rotation of the movable strut relative to the mounting seat and / or the protective frame, thereby realizing the extension and / or contraction of the panel.

4. The drone according to claim 3, characterized in that: After the panel is fully extended, the movable support rod can also provide support for the panel to prevent the panel from being significantly deformed or shaken; and / or The mounting seat is detachably connected to the protective frame; and / or The protective frame can be removed from the drone body or the rotor unit together with the noise reduction component; and / or After the panel is fully retracted, the movable struts of each set of drive units are tilted relative to the height direction of the drone, and the top frame and the bottom frame are close to the mounting seat to minimize the distance between the top frame and the bottom frame. At this time, the panel is compressed between the top frame and the bottom frame to reduce the side area of ​​the noise reduction component.

5. The drone according to claim 2, characterized in that: The noise reduction assembly also includes a top frame connected to the top edge of the panel and a bottom frame connected to the bottom edge; The driving mechanism includes at least two groups of driving units respectively arranged on the front and rear sides of the drone or respectively arranged on the left and right sides of the drone, each group of the driving units includes a movable strut, one end of the movable strut is rotatably connected to the bottom frame, and the other end is slidably connected to the top frame, and the top frame is moved in a direction away from the ground to move away from the bottom frame through the rotation of the movable strut relative to the bottom frame, thereby achieving the extension of the panel; or, the drone also includes a protective frame connected to the drone body or the rotor unit, the top frame is fixedly connected to the main body of the protective frame, and the bottom frame can move relative to the top frame in a direction close to the ground to move away from the top frame.

6. The drone according to claim 2, characterized in that: The noise reduction assembly further includes a top frame connected to the top edge of the panel and a bottom frame connected to the bottom edge, and the drone further includes a protective frame connected to the drone body or to the rotor unit; The driving mechanism is a telescopic rod or a movable rod connecting the top frame and the protective frame, or a telescopic rod or a movable rod connecting the bottom frame and the protective frame, or a telescopic rod or a movable rod connecting the top frame and the bottom frame.

7. The drone according to claim 2, characterized in that: The noise reduction assembly also includes a top frame connected to the top edge of the panel and a bottom frame connected to the bottom edge; After the panel is fully retracted, the top frame and the bottom frame together form a storage space for accommodating the panel; alternatively, the noise reduction component also includes a mounting seat located between the top frame and the bottom frame and / or the drone also includes a protective frame connected to the drone body or the rotor unit, and after the panel is fully retracted, the top frame, the bottom frame, the protective frame and / or the mounting frame together form a storage space for accommodating the panel.

8. The drone according to claim 7, characterized in that: The mounting seat is detachably connected to the protective frame; and / or The protective frame can be removed from the drone body or the rotor unit together with the noise reduction component.

9. The drone according to claim 2, characterized in that: The top edge of the panel when fully extended is higher than the blades of the rotor unit of the UAV, and the bottom edge of the panel when fully extended is lower than the blades of the rotor unit of the UAV; and / or The panel is provided with a plurality of folding marks or hinge axes which are perpendicular to the telescopic direction thereof.

10. The drone according to claim 2, characterized in that: The drone also includes a protective frame connected to the drone body or the rotor unit, the main body of the protective frame is an annular frame and surrounds all the blades of the rotor unit, and the panel can be sleeved on the protective frame to facilitate the installation and removal of the noise reduction component from the drone; Alternatively, the noise reduction assembly further includes a top frame connected to the top edge of the panel and a bottom frame connected to the bottom edge, and after the panel is fully retracted, the top frame and / or the bottom frame are also used to protect the blades of the rotor unit.

11. The drone according to claim 1, characterized in that: It also includes a protective frame connected to the drone body or the rotor unit, all the rotor units are located on the same side of the protective frame, and the noise reduction component is arranged on the protective frame; The noise reduction component includes at least one rolling curtain mechanism, wherein the rolling curtain mechanism includes a rolling curtain and a roller, the roller is rotatably connected to the protective frame, the rolling curtain is provided with the noise reduction structure and can be rolled up around the roller, one end of the rolling curtain is connected to the roller, and the other end is provided with a strip rod, the protective frame is provided with at least two extensions extending downwardly and spaced apart from each other, the rolling curtain mechanism is located between the two extensions, and the two ends of the strip rod on the rolling curtain mechanism are respectively slidably connected with the two extensions, so that the strip rod can slide downwardly of the drone and away from the roller, thereby realizing the unfolding of the rolling curtain and forming the unfolding surface; or The noise component includes at least one foldable and retractable panel, wherein the panel is provided with the noise reduction structure, one edge of the panel is connected to the protective frame, the protective frame is provided with at least two extensions extending and spaced apart from each other toward the bottom of the drone, the panel is located between the two extensions, and the other edge of the panel away from the protective frame is provided with a strip bar, and the two ends of the strip bar on the panel are respectively slidably connected with the two extensions, so that the strip bar can slide toward the bottom of the drone and away from the protective frame, thereby realizing the unfolding of the panel and forming the unfolding surface, or the edge of the panel away from the main body of the protective frame is directly slidably connected with the two extensions on both sides.

12. The drone according to claim 11, characterized in that: The extension portion serves as a landing gear of the drone, for supporting the weight of the drone after the drone has landed; and / or The panel is also provided with a plurality of folding marks or hinge axes perpendicular to the telescopic direction thereof.

13. The drone according to claim 11, characterized in that: The noise reduction assembly also includes a driver; The rolling curtain is a hard rolling curtain, and the driver is used to drive the reel to rotate bidirectionally so that the strip rod moves away from and approaches the reel; or, the rolling curtain is a soft rolling curtain, and the driver is used to drive the reel to rotate so that the rolling curtain is rolled up around the reel and the strip rod moves closer to the reel, and the noise reduction assembly further includes an elastic member, which is arranged between the strip rod and one end of the extension away from the protective frame and is used to provide an elastic force so that the strip rod can move away from the reel; and / or Connecting structures are arranged at both ends of the reel and the reel is rotatably connected to the connecting structures. The connecting structures can also be detachably connected to the protective frame so that the noise reduction component can be quickly disassembled and assembled on the protective frame.

14. The drone according to claim 11, characterized in that: The noise reduction component also includes: a movable plate and a driver, wherein the movable plate is movably connected to the strip rod, and the driver is used to drive the movable plate to move relative to the strip rod, so that the force of the downwash airflow of the rotor unit on the movable plate is increased to drive the strip rod away from the reel or the protective frame; and An elastic member is used for providing elastic torque to drive the strip rod to approach the reel or the protective frame.

15. The drone according to claim 14, characterized in that: When the UAV flies close to the ground, the driver drives the movable plate to deflect relative to the strip rod toward the side where the rotor unit is located, so that the impact force of the downwash airflow of the rotor unit on the side of the movable plate opposite to the rotor unit increases, so that the movable plate starts to move toward the bottom of the UAV and drives the strip rod away from the reel; or The movable plate is slidably connected to the strip rod, and the driver can drive the movable plate to slide relative to the strip rod toward the side where the rotor unit is located and toward the side away from the rotor unit, so as to adjust the force of the downwash airflow of the rotor unit on the movable plate.

16. The drone according to claim 1, wherein: The noise reduction component also includes: A movable plate and a driver, wherein the driver is used to drive the movable plate to move so that the force of the downwash airflow of the rotor unit on the movable plate is increased to drive the noise reduction component to extend and form the deployment surface.

17. The drone according to claim 16, characterized in that: The noise reduction component further includes an elastic member, which is used to provide an elastic torque or an elastic force to drive the noise reduction component to collapse.

18. The drone according to any one of claims 14 to 17, characterized in that: The movable plate is provided with a noise reduction structure, and the movable plate is also used to reduce the diffraction of the noise generated by the rotor unit relative to the noise reduction component; And / or, the movable plate is a flat plate, and during the process of the movable plate moving toward the side where the rotor unit is located, a fold angle in the range of 100 degrees to 170 degrees is finally formed between a surface of the movable plate opposite to the rotor unit and the unfolded surface of the noise reduction component.

19. The drone according to any one of claims 1 to 17, characterized in that: The UAV includes a flight controller and a sensor for measuring wind speed or wind strength, and the flight controller is electrically connected to the sensor to measure wind speed or wind strength; when the UAV flies close to the ground, if the measured wind speed or wind strength is too large, the flight controller can control the noise reduction component to stop extending and keep the noise reduction component in a retracted state.

20. The drone according to any one of claims 1 to 17, characterized in that: The noise reduction structure is a sound absorbing structure or a sound insulating structure; or The noise reduction structure is a material or coating that can effectively reflect sound; or The noise reduction structure is an airflow regulating structure that can improve the airflow near or upstream and downstream of the blades of the rotor unit, thereby reducing the noise generated by the interaction between the blades and the airflow.

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