Airframe balancing drone and control method thereof

Abstract

The present invention belongs to the technical field of unmanned aerial vehicles, and relates to a fuselage-balanced unmanned aerial vehicle and a control method thereof. The unmanned aerial vehicle of the present invention adopts the tilt-rotor technology, and the rotor bracket is rotated by the rotor tilt device to control the inclination angle of the rotor. When adjusting the flight attitude, it is not necessary to adjust the fuselage attitude. At the same time, a fuselage balance controller and a fuselage balance actuator are provided to offset the fuselage tilt caused by wind. The fuselage can maintain balance during flight, and the wind resistance can be improved. The flight stability is increased, and it is suitable as a camera platform. Compared with traditional helicopters, the unmanned aerial vehicle does not have a complex tilting plate structure, and a simple-structured rotor tilt device is used to control the rotor inclination angle. Compared with multi-rotor unmanned aerial vehicles, the unmanned aerial vehicle has only one lift device. In addition, the fuselage balance actuator used is also a simple-structured component, and the whole machine has a simple structure and low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of unmanned aerial vehicles, and more specifically, relates to a fuselage-balanced unmanned aerial vehicle and a control method thereof. Background Art

[0002] In recent years, with the development of microelectronics technology and new materials, consumer drones (mainly helicopter drones) have developed rapidly. Early consumer drones were traditional helicopters, mainly in two configurations: coaxial twin-propellers and single propeller plus tail rotor. The structure of the swash plate of traditional helicopters is too complicated, difficult to manufacture, and has low reliability. Correspondingly, multi-rotor drones have a simple structure, are easy to manufacture, and have high reliability. Currently, multi-rotor drones have become the mainstream of the market, among which quad-rotor drones are the most popular type of multi-rotor drones.

[0003] The main application of consumer drones is photography, which requires a very high balance of the drone body. Otherwise, the constant shaking of the body will drive the camera to shake continuously, which will seriously affect the image effect. However, according to the flight control principle of traditional helicopters and multi-rotor drones, drones cannot keep the body stable during flight. In the case of acceleration and deceleration, wind speed changes or wind direction changes, drones need to do pitch and / or roll movements to achieve flight control. For example, when flying forward, the drone must lower its head to tilt the rotor forward to generate forward thrust, and when flying sideways, the drone must tilt the rotor to generate lateral thrust, and when there is side wind, the drone must tilt the rotor to resist the wind. The pitch and roll movements of the drone are frequent and large.

[0004] Patents with announcement numbers CN106428543B and CN206243472U propose a tilt-rotor control device, which includes two rotating mechanisms that can control the rotor to rotate around two rotation axes, thereby controlling the inclination angle of the rotor and realizing the flight control of the UAV. The UAV using this control device is different from the flight controller principle of the above-mentioned traditional helicopters and multi-rotor UAVs. When adjusting the inclination angle of the rotor, the fuselage attitude does not need to be adjusted accordingly, so the fuselage is balanced when the flight attitude is adjusted. However, this control method has a problem: the thrust of the rotor cannot be used to control the fuselage attitude. The main forces that determine the fuselage attitude are wind force (or other external forces) and fuselage gravity. When affected by wind force, the fuselage will tilt with the wind, and the inclination angle is mainly determined by the size of wind force and gravity. For micro-UAVs, due to the small weight of the fuselage, when the wind force is large, the fuselage tilt angle will be large. When the wind direction and wind speed change frequently, it may even trigger back and forth oscillation, affecting flight stability.

[0005] A simple way to solve the problem of poor images caused by the constant shaking of the drone body is to use digital image stabilization technology, but digital image stabilization technology cannot obtain very satisfactory images. The current solution for mid-to-high-end drones is to hang the camera on a gimbal, and the rotation of the gimbal can offset the shaking of the fuselage, which can obtain relatively satisfactory images. However, due to the light body of micro drones, compared with heavier large drones, larger pitch angles or roll angles need to be adjusted to generate enough force to complete the same flight attitude control, which means that the gimbal needs to rotate faster and more significantly. However, the space of micro drones is small, and only small and low-performance gimbals can be placed. Therefore, when encountering strong winds, especially when the wind speed and wind direction change frequently, the gimbal still cannot completely offset the tilting movement of the fuselage, resulting in poor shooting images.

[0006] In recent years, AR / VR technology and applications have developed rapidly, and panoramic image shooting is an important direction in the field of future imaging. The shooting of panoramic images requires multiple cameras to be arranged around (at least 4 for 360° images and at least 6 for 720° images), all cameras shoot synchronously, and then use image algorithms to stitch the images taken by all cameras. The current method of flying panoramic images is: use a gimbal to hang a spherical pod, and install multiple cameras around the pod for shooting. Because the pod is hung under the drone, it is impossible to shoot the scene above the pod, and it is impossible to shoot 720° images. A flying platform with a fuselage that always maintains balance and can shoot 720° panoramic images is of great value to the future development of panoramic imaging. Summary of the invention

[0007] The purpose of the present invention is to provide a fuselage-balanced UAV and a control method thereof, so as to solve the technical problem that the existing UAV fuselage constantly shakes and affects image shooting.

[0008] To achieve the above object, the technical solution adopted by the present invention is: to provide a fuselage balancing drone, comprising:

[0009] body;

[0010] Rotor bracket;

[0011] A lift device mounted on the rotor support, the lift device comprising a rotor;

[0012] A rotor tilt device installed on the fuselage and used to rotate the rotor bracket to control the inclination angle of the rotor;

[0013] at least one fuselage balancing actuator for outputting a moment causing the fuselage to generate a tilting motion; and

[0014] A fuselage balancing controller is used to control the action of the fuselage balancing actuator to keep the fuselage balanced.

[0015] The technical effects of the present invention relative to the prior art are:

[0016] 1. The UAV of the present invention adopts the tilt-rotor technology. The rotor bracket is rotated by the rotor tilt device to control the inclination angle of the rotor. When adjusting the flight attitude, there is no need to adjust the fuselage attitude. At the same time, a fuselage balance controller and a fuselage balance actuator are provided to offset the fuselage tilt caused by wind. The fuselage can maintain balance during flight, and is suitable as a camera platform.

[0017] 2. After the UAVs described in patents No. CN106428543B and CN206243472U are miniaturized, their wind resistance is relatively low. The UAV of the present invention is equipped with a fuselage balance controller and a fuselage balance actuator to improve the wind resistance and increase the flight stability.

[0018] 3. Compared with traditional helicopters, the UAV of the present invention does not have a complex swash plate structure, and uses a simple rotor tilt device to control the rotor inclination angle. Compared with multi-rotor UAVs, the UAV of the present invention has only one lift device. In addition, the fuselage balancing actuator used is also a component with a simple structure, and the whole machine has a simple structure and low cost.

[0019] Optionally, the fuselage balancing drone further comprises a rotor protection frame mounted on the rotor bracket, the rotor protection frame being a hollow structure, the rotor being placed inside the rotor protection frame, and the rotor protection frame being used to protect the rotor. The fuselage of the drone of the present invention may be a hollow frame structure, the lift device being mounted inside the fuselage, and a plurality of cameras being arranged around the fuselage frame for shooting 720° panoramic images.

[0020] The present invention provides a control method for a fuselage-balanced UAV, comprising the following steps:

[0021] Step S1, setting at least one working mode for the fuselage balancing drone, and setting a fuselage balancing control target for each working mode;

[0022] Step S2, the fuselage balance controller receives input data required for balance control;

[0023] Step S3, the fuselage balancing controller calculates the control amount of the fuselage balancing actuator according to the current working mode of the fuselage balancing UAV, the input data in step S2 and the fuselage balancing target in step S1 corresponding to the current working mode;

[0024] Step S4, controlling the action of the fuselage balancing actuator according to the control amount;

[0025] Step S5, looping through steps S2 to S4 to make the fuselage posture meet the fuselage balance control target.

[0026] The technical effects of the present invention relative to the prior art are:

[0027] 1. The UAV of the present invention adopts the tilt-rotor technology. The rotor bracket is rotated by the rotor tilt device to control the inclination angle of the rotor. When adjusting the flight attitude, there is no need to adjust the fuselage attitude. At the same time, a fuselage balance controller and a fuselage balance actuator are provided to offset the fuselage tilt caused by wind. The fuselage can maintain balance during flight, and is suitable as a camera platform.

[0028] 2. After the UAVs described in patents No. CN106428543B and CN206243472U are miniaturized, their wind resistance is relatively low. The UAV of the present invention is equipped with a fuselage balance controller and a fuselage balance actuator to improve the wind resistance and increase the flight stability.

[0029] 3. Compared with traditional helicopters, the UAV of the present invention does not have a complex swash plate structure, and uses a simple rotor tilt device to control the rotor inclination angle. Compared with multi-rotor UAVs, the UAV of the present invention has only one lift device. In addition, the fuselage balancing actuator used is also a component with a simple structure, and the whole machine has a simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 A three-dimensional assembly diagram of a fuselage-balanced drone provided by a first embodiment of the present invention;

[0032] Figure 2 for Figure 1 Exploded view of the fuselage-balanced drone;

[0033] Figure 3 A three-dimensional assembly diagram of a fuselage-balanced drone provided by a second embodiment of the present invention;

[0034] Figure 4 A three-dimensional assembly diagram of a fuselage-balanced drone provided by a third embodiment of the present invention;

[0035] Figure 5 A three-dimensional assembly diagram of a fuselage-balanced drone provided by a fourth embodiment of the present invention;

[0036] Figure 6 (a) Figure 6 (b) are a three-dimensional assembly diagram and a partial enlarged diagram of a fuselage-balanced UAV provided by a fifth embodiment of the present invention;

[0037] Figure 7 (a) Figure 7 (b) are a three-dimensional assembly diagram and a partial enlarged diagram of a fuselage-balanced UAV provided by a sixth embodiment of the present invention;

[0038] Figure 8 for Figure 1 Schematic diagram of the structure of the fuselage balance drone when folded;

[0039] Fig. 9 A three-dimensional assembly diagram of a fuselage-balanced UAV provided by two sets of embodiments of the present invention;

[0040] Fig.10 for Fig. 9 Schematic diagram of the structure of the fuselage balance drone when folded;

[0041] Fig.11 A three-dimensional assembly diagram of a fuselage-balanced UAV provided by three sets of first embodiments of the present invention;

[0042] Fig.12 A three-dimensional assembly diagram of a fuselage-balanced UAV provided by three sets of second embodiments of the present invention;

[0043] Fig.13 Flow chart of a control method for a fuselage balancing drone provided by four groups of embodiments of the present invention;

[0044] Fig.14 The four groups of embodiments of the present invention provide Figure 1 Flowchart of the control method of the drone shown. DETAILED DESCRIPTION

[0045] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention 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 invention and are not intended to limit the present invention.

[0046] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present invention.

[0047] In addition, the terms "first" and "second" 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, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 the embodiments of the present invention can be understood according to specific circumstances.

[0049] See also Figure 1 and Figure 2 In one embodiment of the present invention, a fuselage balancing drone is provided, which includes a fuselage 100, a rotor bracket 500, a lift device 200, a rotor tilt device 400, a fuselage balancing actuator (310, 320, 330, 340) and a fuselage balancing controller (not shown), wherein the lift device 200 is mounted on the rotor bracket 500, and the lift device 200 includes a rotor 220; the rotor tilt device 400 is mounted on the fuselage 100, and is used to rotate the rotor bracket 500 to control the inclination angle of the rotor 220; the fuselage balancing actuator (310, 320, 330, 340) is used to output a torque that causes the fuselage 100 to generate a tilting motion; and the fuselage balancing controller is used to control the action of the fuselage balancing actuator (310, 320, 330, 340) to keep the fuselage 100 balanced.

[0050] The unmanned aerial vehicle adopts the tilt-rotor technology, and the rotor bracket 500 is rotated by the rotor tilt device 400 to control the inclination angle of the rotor 220. Therefore, when adjusting the flight attitude, it is not necessary to adjust the attitude of the fuselage 100. At the same time, a fuselage balance controller and a fuselage balance actuator (310, 320, 330, 340) are provided to offset the fuselage tilt caused by wind. During the flight, the fuselage 100 can maintain balance, and can improve wind resistance and increase flight stability. It is suitable for use as a camera platform. Compared with traditional helicopters, the unmanned aerial vehicle does not have a complex tilt plate structure, and uses a simple rotor tilt device 400 to control the inclination angle of the rotor 220. Compared with multi-rotor unmanned aerial vehicles, the unmanned aerial vehicle has only one lift device 200. In addition, the fuselage balance actuator (310, 320, 330, 340) used is also a simple component. It can be seen that the structure of the unmanned aerial vehicle of the present invention is simple and the cost is low.

[0051] It should be noted that the fuselage balance controller calculates the control amount of each fuselage balance actuator according to the posture of the fuselage 100 and other data, and then controls each fuselage balance controller to act in coordination to achieve balance control of the fuselage 100 .

[0052] Embodiment group:

[0053] This embodiment describes a drone proposed by the present invention, such as Figure 1 , Figure 2 As shown, it includes a fuselage 100, a lift device 200, a fuselage balancing actuator (310, 320, 330, 340), a fuselage balancing controller (not shown), a rotor tilt device 400, and a rotor bracket 500.

[0054] In another embodiment of the present invention, the fuselage 100 is an "L"-shaped structure, including a first body 110 and an arm 120. The first body 110 is a long strip structure, and the arm 120 is disposed at one end of the first body 110. The first body 110 contains drone functional modules such as a battery, an optical flow sensor, a visual analysis module, a gimbal, and a camera 700, which contain most of the weight of the drone.

[0055] In another embodiment of the present invention, a flight controller (not shown) is further included, and the flight controller controls the flight of the UAV according to data from various sensors and flight mission requirements, which belongs to the prior art. The electronic control component including the flight controller can be installed at any position of the UAV, usually installed in the first body 110.

[0056] In another embodiment of the present invention, the lift device 200 includes two motors 210 and two rotors 220. The two motors 210 are installed on the rotor bracket 500, one facing upward and the other facing downward. The two rotors 220 are respectively installed on the output shafts of the two motors 210 and rotate in opposite directions. The rotational torques of the two rotors 220 can offset each other.

[0057] In another embodiment of the present invention, a rotor protection frame 600 is further included. The rotor protection frame 600 is installed on the rotor bracket 500 and wraps the lift device 200 inside to provide protection for the rotor 220 and avoid accidental injury to people. Figure 1 The rotor protection frame 600 shown is a hollow circular frame. The circular frame can be a hollow structure to reduce weight, and mesh covers can be added to the upper and lower ends of the circular frame to improve safety.

[0058] In another embodiment of the present invention, the rotor tilt device 400 includes a first rotating mechanism 410, a first rotating controller 420, an adapter bracket 430, a second rotating mechanism 440 and a second rotating controller 450. The rotor bracket 500 is rotatably mounted on the adapter bracket 430 through the first rotating mechanism 410, and the adapter bracket 430 is rotatably mounted on the arm 120 through the second rotating mechanism 440. In principle, the rotation axis R1 of the first rotating mechanism 410 and the rotation axis R2 of the second rotating mechanism 440 are all feasible as long as they are not parallel. In this embodiment, the rotation axis R1 and the rotation axis R2 are orthogonal, which is a preferred design and can simplify the design of the flight controller. If the orthogonal design is difficult to achieve, a mutually perpendicular design can also achieve better results. The lift device 200 is controlled by the first rotating controller 420 and the second rotating controller 450 to rotate around the rotation axis R1 and the rotation axis R2 respectively, and then the inclination angle of the rotor 220 is controlled. It should be noted that the sensitivity and control accuracy of the first rotating controller 420 and the second rotating controller 450 are required to be high, otherwise it will affect the control stability of the drone.

[0059] In this embodiment, the first rotating mechanism 410 adopts a shaft system structure, which has many components. Figure 2In the figure, the first bearing 411 and the first transmission shaft 412 are used as the two main components for illustration. In the figure, the first bearing 411 is set on the adapter bracket 430, and the first transmission shaft 412 is set at the end of the rotor bracket 500. In fact, the opposite setting is also possible, that is, the first transmission shaft is set on the adapter bracket, and the first bearing is set at the end of the rotor bracket. Like the first rotating mechanism 410, the second rotating mechanism 440 also adopts a shaft system structure. In the figure, the second bearing 441 and the second transmission shaft 442 are used as the two main shaft system components for illustration. The second bearing 441 is set on the arm, and the second transmission shaft 442 is set at the end of the adapter bracket 430. In fact, the opposite setting is also possible. The first rotation controller 420 and the second rotation controller 450 are a kind of servo, including components such as a motor, a transmission reduction component and a motor control component. In the figure, a motor and a gear set are used to output rotation according to a control signal, which belongs to the prior art.

[0060] The flight control principle of the above-mentioned UAV is as follows: during flight, the first body 110 is located below the rotor 220. The first body 110 contains most of the weight of the UAV. Based on the supporting effect of the gravity of the first body 110, the rotor bracket 500 can be controlled to rotate around the rotation axis R1 through the first rotation controller 420; the adapter bracket 430 can be controlled to rotate around the rotation axis R2 through the second rotation controller 450, so the rotor 220 can be controlled to rotate around the rotation axis R1 and the rotation axis R2, and then the UAV is controlled to move along the X-axis and Y-axis or to offset the external force of the X-axis and Y-axis to maintain hovering; by controlling the rotation speed of the two rotors 220, the rotation torque difference of the two rotors 220 is adjusted to generate a yaw moment, and at the same time, the total lift generated by the two rotors 220 is controlled to remain unchanged, thereby controlling the yaw motion of the UAV; by controlling the rotation speed of the two rotors 220, the total lift generated by the two rotors 220 is adjusted, and at the same time, the rotation torque of the two rotors 220 is kept offset to achieve the lifting and lowering control of the UAV. As can be seen from the above, the drone of this embodiment adopts tilt-rotor technology. The advantage of this control method is that the drone can adjust the inclination angle of the rotor 220 to achieve flight control without adjusting the posture of the fuselage 100, that is, the fuselage 100 can still remain stable when the drone adjusts its flight posture.

[0061] The technical characteristics of the above control method are: the thrust of the rotor 220 cannot be used to control the posture of the fuselage 100. The main forces that determine the posture of the fuselage 100 are wind force (or other external forces) and fuselage gravity. When affected by wind force or acceleration and deceleration, the fuselage 100 will tilt with the lift center (the midpoint of the line connecting the upper and lower rotor center points) as the fulcrum, and the tilt angle is determined by the size of the wind force and the fuselage gravity. For micro-sized drones, since the weight of the fuselage is too light, the tilt angle will be larger, which will not only affect the shooting, but may even trigger back and forth oscillations and affect the flight stability. The drone of this embodiment includes a fuselage balance controller and four fuselage balance actuators (310, 320, 330, 340) for controlling the tilting movement of the above-mentioned fuselage 100.

[0062] like Figure 1 As shown, the arrow direction of the X-axis is set to the direction of the nose, then the straight line passing through the lift center and parallel to the Y-axis is the pitch axis of the drone, and the straight line passing through the lift center and parallel to the X-axis is the roll axis of the drone. Two of the fuselage balancing actuators (310, 320) of the drone in this embodiment are arranged at two ends of the first body 110, on both sides of the pitch axis, and the other two fuselage balancing actuators (330, 340) are arranged on the rotor protection frame 600, on both sides of the roll axis. The basic structure of the fuselage balancing actuator (310, 320, 330, 340) includes a balancing guide vane (311, 321, 331, 341) and a balancing servo, and its working principle is: one surface of the balancing guide vane (311, 321, 331, 341) faces the downwash airflow of the rotor 220, and the downwash airflow of the rotor 220 generates pressure on the surface, thereby generating a torque that causes the drone to generate a tilting motion; the balancing servo controls the rotation of the balancing guide vane to adjust its angle of attack relative to the rotor airflow, so that the area of ​​the oncoming airflow becomes larger or smaller, thereby controlling the magnitude of the generated torque. For example, the fuselage balancing actuator (310, 320) on the first fuselage 110 can generate a pitching torque that causes the fuselage 100 to perform a pitching motion. If the balance guide vane 321 of the fuselage balance actuator 320 at the right end rotates outward at an angle b to increase the torque, and the balance guide vane 311 of the fuselage balance actuator 310 at the left end rotates toward the fuselage at an angle a to reduce the torque, a pitch torque is generated to rotate the fuselage 100 clockwise around the pitch axis. If the balance guide vanes (311, 321) of the two fuselage balance actuators (310, 320) rotate in opposite directions, a pitch torque is generated to rotate the fuselage 100 counterclockwise around the pitch axis. Similarly, the two fuselage balance actuators (330, 340) on the rotor protection frame 600 can generate a rolling torque to rotate the fuselage 100 around the roll axis. The balance servo includes components such as a motor, a transmission reduction component, and a motor control component, which are used to output rotation according to a control signal, which belongs to the prior art.

[0063] In this embodiment, each fuselage balancing actuator can be provided with only one balancing servo to control the synchronous rotation of two balancing guide vanes. Since the airflows received by the two balancing guide vanes are different, the pressures received by the two balancing guide vanes with the same opening angles are different. At this time, the torque generated by the fuselage balancing actuator will cause the fuselage to rotate around more than one axis. For example, the torque generated by the fuselage balancing actuator (310, 320) on the first fuselage 110 will not only be a pitching torque, but also a part of the rolling torque. Similarly, the torque generated by the fuselage balancing actuator (330, 340) on the rotor protection frame 600 will not only be a rolling torque, but also a part of the pitching torque. However, the fuselage balancing controller can control the coordinated actions of the four fuselage balancing actuators (310, 320, 330, 340) to control the balance of the fuselage. In order to simplify the control, each fuselage balancing actuator can be provided with two balancing servos to respectively control the angles of the two balancing guide vanes, so that the torque of a single fuselage balancing actuator is only a pitch torque or a roll torque, but more components are used.

[0064] In another embodiment of the present invention, the fuselage balancing actuator should be set at a position with a larger force arm as much as possible, which can improve power efficiency. For example, in this embodiment, the two fuselage balancing actuators (310, 320) on the first body 110 are set at the two ends of the first body 110, which is the position where the force arm of the pitch moment is the largest. In addition, there are many implementation methods for the setting position of the fuselage balancing actuator, such as, Figure 1 The two fuselage balancing actuators (310, 320) of the drone provided on the first fuselage may also be provided on the rotor protection frame 600; or Figure 3 As shown, two brackets 130 are provided on the first body 110 for mounting the fuselage balancing actuator 330. The two fuselage balancing actuators 330 generate a rolling moment, replacing the Figure 1 The drone shown has two fuselage balancing actuators installed on the rotor protection frame 600, and the roots of the two brackets 130 can be provided with hinge mechanisms to fold and recover the drone.

[0065] Figure 1 The drone shown in the figure is provided with two fuselage balancing actuators in both the pitch axis and the roll axis. Figure 4 In the drone shown, it is also feasible to set only one fuselage balancing actuator (310, 320) in each axis. With this configuration, the structure is simpler and the weight is smaller, but the torque is smaller and the wind resistance is reduced. It should be noted that since the fuselage balancing actuator (310, 320) can only output unidirectional torque, their balancing guide vanes (311, 321) should be opened at a certain angle to generate an initial torque when hovering without wind, and the synergistic effect with the gravity of the fuselage is achieved by increasing or decreasing the torque to achieve bidirectional control.

[0066] In another embodiment of the present invention, Figure 5 As shown, the fuselage balancing actuator 310 on the first body 110 is another implementation method based on the guide vane technology. This fuselage balancing actuator 310 also includes a balancing guide vane 311 and a balancing servo. The working principle of the balancing guide vane 311 of this fuselage balancing actuator 310 is different. It adopts the fixed-wing principle. The downwash airflow of the rotor will produce a pressure difference on the two surfaces of the balancing guide vane 311, thereby generating a torque. The balancing servo controls the rotation of the balancing guide vane 311 and adjusts the angle of attack between the balancing guide vane and the rotor airflow to adjust the magnitude of the torque. This implementation method has high power efficiency, but is easily affected by external airflow.

[0067] In another embodiment of the present invention, the fuselage balancing actuator is also implemented based on a fan, such as Figure 6 The fan 350 in the middle of the first body 110 of the drone shown is a fuselage balancing actuator. The thrust of the fan 350 can generate a rolling torque. Two groups of blades (351, 352) are arranged in the fan. The air outlet directions of the two groups of blades (351, 352) are opposite, so that the fan can output torques of substantially the same magnitude when rotating clockwise or counterclockwise. Controlling the rotation direction of the fan 350 can control the direction of the torque, and adjusting the rotation speed of the fan 350 can control the magnitude of the torque.

[0068] In another embodiment of the present invention, Figure 7 The fan 360 provided on the first body 110 is another implementation method of the body balancing actuator based on a fan. The fan 360 is provided with two air outlets 361, and valves are provided on the air outlets 361. Air is sucked in from the top and discharged from the air outlets 361 to generate torque. The direction of the torque can be controlled by opening and closing the valves of the two air outlets 361, and the magnitude of the torque can be controlled by adjusting the speed of the fan. The valve is movably installed on the air outlet 361, and is driven to move by the driving member to realize the opening and closing of the air outlet 361.

[0069] In another embodiment of the present invention, the setting of the fuselage balancing actuator is related to the specific application requirements of the UAV. The balance requirement for one axis of the pitch axis or the roll axis may be high, and the requirement for the other axis may be low. In this case, the fuselage balancing actuator may be set only in one axis, or one fuselage balancing actuator may be set in one axis, and two fuselage balancing actuators may be set in another axis. In addition, the specific performance of the fuselage balancing actuator is also related to the specific application requirements of the UAV.

[0070] In another embodiment of the present invention, the fuselage of the drone is an "L"-shaped structure, and the drone arm 120 and the first body 110 enclose a space, such as Figure 8As shown, by rotating the first rotating mechanism 410 and the second rotating mechanism 440, the lift device 200 and the rotor protection frame 600 can be integrated into the space; in addition, the balance guide vanes (311, 321) of the fuselage balance actuator (310, 320) on the first body 110 can be rotated to fit with the outer shell of the first body 110, and the balance guide vanes (331, 341) of the fuselage balance actuator (330, 340) on the rotor protection frame 600 can be rotated into the rotor protection frame 600, thereby realizing the folding and recycling of the drone, making the recycling size of the drone small and portable. It is worth noting that the rotor protection frame 600 of the drone of the present invention can be fixedly mounted on the rotor bracket 500, so that the rotor protection frame 600 does not need to be disassembled each time the drone is folded and released, taking into account the ease of use and safety of the drone.

[0071] Embodiment 2 group:

[0072] This embodiment describes a drone proposed by the present invention, such as Fig. 9 As shown, it includes a fuselage 100, a lift device 200, a fuselage balance actuator 310, a rotor tilt device 400, a rotor bracket 500 and a fuselage balance controller (not shown). The fuselage balance controller is the same as that of the first drone of the embodiment, and will not be described in detail.

[0073] In another embodiment of the present invention, the fuselage 100 is a "U"-shaped structure, including a first body 110 and two arms 120. The first body 110 is a long strip structure, and the two arms 120 are respectively arranged at both ends of the first body 110. The first body 110 contains drone functional modules such as batteries, optical flow sensors, visual analysis modules, gimbals, and cameras 700, which contain most of the weight of the drone.

[0074] In another embodiment of the present invention, the lift device 200 is mounted on the rotor bracket 500, and the rotor tilt device 400 includes a first rotating mechanism 410, a first rotating controller 420, an adapter bracket 430, a second rotating mechanism 440, a second rotating controller 450 and a third rotating mechanism 460. The rotor bracket 500 is rotatably mounted at the middle position of the adapter bracket 430 through the first rotating mechanism 410, and the two ends of the adapter bracket 430 are rotatably mounted on the two arms 120 through the second rotating mechanism 440 and the third rotating mechanism 460, respectively. The rotation axes of the second rotating mechanism 440 and the third rotating mechanism 460 coincide, so the adapter bracket 430 can rotate relative to the fuselage 100. The rotor bracket 500 is controlled by the first rotating controller 420 to rotate relative to the adapter bracket 430 around the rotation axis R1 of the first rotating mechanism 410, and the adapter bracket 430 is controlled by the second rotating controller 450 to rotate relative to the fuselage 100 around the rotation axis R2 of the second rotating mechanism 440.

[0075] In another embodiment of the present invention, the lift device of this embodiment includes a motor 210, a rotor 220, a yaw guide vane (230, 240) and a yaw servo. The motor 210 is mounted on the rotor bracket 500, and the rotor 220 is mounted on the output shaft of the motor 210. The yaw guide vanes (230, 240) are mounted below the rotor 220, and the downwash airflow of the rotor 220 is used to generate a torque that causes the drone to yaw. Two yaw guide vanes 230 are fixedly installed, and the other two yaw guide vanes 240 are movable. The yaw servo controls the movable yaw guide vanes 240 to rotate and adjust the yaw torque. The yaw servo includes components such as a motor, a transmission reduction component and a motor control component, which are used to output rotation according to a control signal, which belongs to the prior art.

[0076] The flight control of the drone of this embodiment is the same as that of the drone of the first embodiment except for the yaw motion control, and will not be described in detail. The yaw motion control principle of the drone of this embodiment is as follows: the yaw guide vanes (230, 240) are based on the fixed-wing principle, and the downwash airflow of the rotor 220 flows through the yaw guide vanes (230, 240), and a pressure difference is generated on the two surfaces of the yaw guide vanes (230, 240), thereby generating a yaw moment. The yaw servo controls the rotation of the movable yaw guide vanes 240 to adjust the angle of attack relative to the rotor airflow, thereby controlling the magnitude of the torque generated and realizing the yaw motion control of the drone.

[0077] In another embodiment of the present invention, this embodiment includes four fuselage balancing actuators 310 disposed on the fuselage 100, each fuselage balancing actuator 310 includes a balancing guide vane 311 and a balancing servo, and its working principle is the same as Figure 1 The fuselage balancing actuators of the drone shown are the same. It should be noted that the torque generated by each fuselage balancing actuator 310 of this embodiment has both pitch torque and rolling torque components, and four fuselage balancing actuators 310 need to work together to achieve the balance control of the fuselage. Note that in order to make the rolling torque large enough, the length of the balancing guide plate 311 of the fuselage balancing actuator of this embodiment is longer than Figure 1 The length of the drone shown can increase the moment arm of the rolling moment.

[0078] It should be noted that the fuselage balancing actuator discussed in the first group of drones in the embodiment can also be used in the drone of this embodiment.

[0079] In another embodiment of the present invention, the U-shaped fuselage 100 of the drone of this embodiment can bear a heavier lift device, and the space surrounded by the two arms 120 and the first body 110 can accommodate the lift device 200 and the rotor protection frame 600, so as to realize the folding and recovery of the drone. Fig.10 shown.

[0080] Embodiment three groups:

[0081] This embodiment describes a panoramic photography drone, such as Fig.11 As shown, it includes a fuselage 100, a lifting device 200, a fuselage balancing actuator (310, 320), a rotor tilting device 400, a rotor bracket 500 and a fuselage balancing controller (not shown). The fuselage balancing controller and the lifting device of the drone of this embodiment are the same as those of the drone of the first embodiment, and will not be described in detail.

[0082] In the embodiment of the present invention, the fuselage 100 is an ellipsoidal hollow frame structure, and the fuselage 100 includes a first body 110, which is placed in the lower hemisphere, and contains batteries and other electronic components, including most of the weight of the drone. A plurality of cameras 700 are installed around the fuselage frame to capture 720° panoramic images. Preferably, the camera uses optical image stabilization.

[0083] In another embodiment of the present invention, the lift device 200 is mounted on the rotor bracket 500, and the rotor tilt device 400 includes a first rotating mechanism 410, a first rotating controller 420, an adapter bracket 430, a second rotating mechanism 440, a second rotating controller 450, a third rotating mechanism 460, and a fourth rotating mechanism 470. The adapter bracket 430 is an annular structure, and the two ends of the rotor bracket 500 are respectively rotatably mounted on the adapter bracket 430 through the first rotating mechanism 410 and the third rotating mechanism 460, and the rotation axis of the first rotating mechanism 410 coincides with the rotation axis of the third rotating mechanism 460, so the rotor bracket 500 can rotate relative to the adapter bracket 430. The two ends of the adapter bracket 430 are respectively rotatably mounted on the fuselage 100 through the second rotating mechanism 440 and the fourth rotating mechanism 470, and the rotation axes of the second rotating mechanism 440 and the fourth rotating mechanism 470 coincide, so the adapter bracket 430 can rotate relative to the fuselage 100. The first rotation controller 420 controls the rotor bracket 500 to rotate relative to the adapter bracket 430 around the rotation axis of the first rotation mechanism 410, and the second rotation controller 450 controls the adapter bracket 430 to rotate relative to the fuselage 100 around the rotation axis of the second rotation mechanism 440. The rotor tilt device 400 of the drone of this embodiment has a stronger structural support force and can support a larger lift device 200. The flight control principle of the drone of this embodiment is exactly the same as that of the drone of the first embodiment.

[0084] In another embodiment of the present invention, Fig.11As shown, the fuselage balancing actuator (310, 320) of the drone of this embodiment uses three fans. Assuming that the arrow on the X-axis points to the nose, the X-axis is the roll axis and the Y-axis is the pitch axis. The wind direction of the middle fan is parallel to the X-axis, generating a pitch moment, and the wind directions of the two fans on both sides are parallel to the Y-axis, generating a roll moment. Another implementation method can use two fans, retain the middle fan, and set another fan below the middle fan, whose wind direction is parallel to the Y-axis, instead of Fig.11 There are two fans on both sides of the middle, but when the fans are set at this position, the force arm is short and the power efficiency is low; an alternative implementation is to set a fan at a position symmetrical to the middle fan in the lower hemisphere, with its wind direction parallel to the Y axis, so as to efficiently generate a rolling moment.

[0085] It should be noted that the fuselage balancing actuators in the first embodiment and the second embodiment can be used in the drone of this embodiment. Fig.12 The figure shows an embodiment, in which four fuselage balancing actuators 310 based on guide vane technology are arranged on the lower hemisphere of the drone, and the other parts are similar to Fig.11 The drones shown are identical.

[0086] It should be noted that the performance of the fuselage balancing actuator of the drone of this embodiment is higher, so that the fuselage can maintain higher stability, which is conducive to image stitching and shooting stable panoramic images.

[0087] Embodiment 4 group:

[0088] like Fig.13 As shown, this embodiment describes a fuselage balancing control method for a fuselage balancing drone of any of the above embodiments, comprising the following steps:

[0089] Step S101, setting the fuselage balance control target for the fuselage balance controller: First, different working modes are set for different working states of the drone according to the application requirements of the drone, and then different fuselage balance control targets are set for each working mode. For example, since the action of the fuselage balance actuator consumes energy, the higher the fuselage balance to be controlled, the greater the energy consumed. A working mode can be set for the working state of the drone when there is no image shooting task, called the flight mode, and a control target with a lower fuselage balance can be set in the flight mode; in addition, another working mode is set for the working state of the drone in the image shooting state, called the shooting mode, and a control target with a high fuselage balance is set;

[0090] Step S102: The fuselage balance controller receives input data required for balance control, such as fuselage attitude data (fuselage pitch angle / pitch velocity, fuselage roll angle / roll velocity), rotor tilt angle / tilt velocity data, etc. In fact, the flight controller of the UAV also needs the above data. The UAV is equipped with a fuselage attitude sensing module and a rotor tilt sensing module to obtain the above data. The usual implementation method is to use an IMU device (including an accelerometer and a gyroscope) to sense the original motion data of the fuselage or rotor, and then use a filtering algorithm (such as an extended Kalman filter algorithm) to eliminate noise and obtain accurate fuselage attitude data and rotor tilt data. This belongs to the prior art.

[0091] Step S103: Based on the above input data, the fuselage balance controller applies the corresponding fuselage balance control target set in step S101 according to the current working mode of the drone, executes the corresponding fuselage balance control algorithm, and calculates the control amount of each fuselage balance actuator according to the deviation value between the current fuselage posture data and the target value set by the fuselage balance control target. The fuselage balance control algorithm can be a PID-based control algorithm or a more complex mathematical model-based control algorithm;

[0092] Step S104, controlling the action of the fuselage balancing actuator according to the calculated control amount;

[0093] Step S105, looping through steps S102 to S104, so that the fuselage posture satisfies the fuselage balance control target.

[0094] Furthermore, based on the above-mentioned fuselage balance control method, Figure 1 and Figure 2 The UAV shown is a specific control object, and a PID-based fuselage balance control method is described in detail below. Figure 1The drone shown is used for selfies by individual users. A feature of the selfie application is that the user issues a shooting command each time he wants to take a photo. As long as the drone can control the body to keep it stable within a short response time after receiving the command, the user's shooting experience will not be affected. Taking advantage of this feature, the working mode of the drone is divided into two working modes, namely flight mode (working state without image shooting task) and shooting mode (working state with image shooting task), and different fuselage balance control targets are set for these two modes: 1. In flight mode, the fuselage balance control target is that the roll angular velocity of the drone is lower than a roll angular velocity threshold and the pitch angular velocity is lower than a pitch angular velocity threshold. This control target only suppresses excessive fuselage tilting movement and does not maintain the absolute balance of the fuselage, so as to reduce power consumption and improve battery life; 2. In shooting mode, the fuselage balance control target is that the pitch angle and roll angle of the fuselage are equal to the target pitch angle and target roll angle respectively. The target pitch angle and target roll angle are the pitch angle and roll angle of the drone when it switches to shooting mode, respectively. This control target keeps the fuselage posture of the drone at the fuselage posture when the user's shooting command is received, so as to shoot stable images.

[0095] In order to facilitate the description of the fuselage balance control method, the pitch axis and roll axis of the drone are first defined. Figure 1 As shown, assuming that the arrow on the X-axis points to the direction of the nose, then the straight line parallel to the Y-axis and passing through the lift center of the rotor is the pitch axis, and the straight line parallel to the X-axis and passing through the lift center of the rotor is the roll axis. p , AR p , A r , AR r are the pitch angle, pitch angular velocity, roll angle and roll angular velocity of the fuselage respectively. Assume that when the nose rotates upward around the pitch axis, A p and AR p The sign is positive, and the fuselage rotates to the right (the Y-axis arrow points downward) around the roll axis. r and AR r The sign of is positive.

[0096] like Fig.14 Shown is applied to Figure 1 The fuselage balance control method of the UAV shown includes the following steps:

[0097] Step S201: The unmanned working state is divided into two working modes: flight mode and shooting mode, and the fuselage balance control target is set for each working mode:

[0098] R1: In flight mode, the fuselage balance control target is that the fuselage pitch rate is lower than the pitch rate threshold AR_THR p , the roll angular velocity of the fuselage is lower than the roll angular velocity threshold AR_THRr ;

[0099] R2: In shooting mode, the fuselage balance control target is that the fuselage pitch angle is equal to the target pitch angle A_FIT p , and the roll angle of the fuselage is equal to the target roll angle A_FIT r , where A_FIT p and A_FIT r They are the pitch angle and roll angle when the drone switches to shooting mode;

[0100] Step S202: The fuselage balance controller receives data required for controlling fuselage balance, including:

[0101] Receive the fuselage attitude data from the existing fuselage attitude perception module, including the current pitch angle A p 、Current pitch angular velocity AR p 、Current roll angle A r 、Current roll angular velocity AR r .

[0102] Step S203: The fuselage balance controller uses the corresponding fuselage balance control target and executes the corresponding fuselage balance control algorithm according to the current working mode of the UAV. k , the control quantities of the pitch moment fuselage balancing actuator (310, 320) and the rolling moment fuselage balancing actuator (330, 340) are C_PITCH(k) and C_ROLL(k) respectively, wherein the initial values ​​C_PITCH(0) and C_ROLL(0) are 0. The fuselage balancing control algorithm is a PID-based control algorithm;

[0103] Step S203A: When the UAV working mode is the flight mode, the fuselage balance control target R1 is used, and the current pitch angular velocity AR p and pitch angular velocity threshold AR_THR p The deviation between the two, and the current roll angular velocity AR r and roll angular velocity threshold AR_THR r The deviation between them is calculated using a fuselage balance control algorithm corresponding to the flight mode. The specific algorithm is as follows:

[0104] Calculate the time T using formula (1) k The current pitch angular velocity AR of the fuselage p (k) and pitch angular velocity threshold AR_THR p The pitch angular velocity deviation e_AR p (k) The current roll angular velocity AR of the fuselage r (k) and roll angular velocity threshold AR_THRr Roll angular velocity deviation e_AR r (k), where abs(x) is the absolute value function of x;

[0105]

[0106] If e_AR p (k) is greater than 0, the current pitch angular velocity of the fuselage exceeds the pitch angular velocity threshold, Tp is set as the current time point, Tp is set as the starting time point of this round of control, and the control amount C_PITCH(k) of the pitch moment fuselage balancing actuator (310, 320) is calculated using PID formula (2); otherwise, C_PITCH(k) is set to 0, and control is stopped;

[0107]

[0108] If e_AR r (k) is greater than 0, the current roll angular velocity of the fuselage exceeds the roll angular velocity threshold, Tr is set as the current time point, Tr is set as the starting time point of this round of control, and the control amount C_ROLL(k) of the roll moment fuselage balancing actuator (330, 340) is calculated using PID formula (3); otherwise, C_ROLL(k) is set to 0 and control is stopped;

[0109]

[0110] Among them, in formula (2) and (3), A_K p , A_K i , A_K d are the proportional, integral and differential control parameters of the PID algorithm respectively; sign(x) is the sign function of x, and the corresponding sign bits are set for C_PITCH(k) and C_ROLL(k) to determine the direction of the control torque.

[0111] Step S203B, after receiving the user's shooting command, the working mode of the drone is switched to the shooting mode, and the fuselage balance control target R2 is adopted. The target pitch angle and target roll angle of the fuselage balance control target are respectively set to the pitch angle and roll angle when the drone is switched to the shooting mode. Then, according to the deviation value between the current pitch angle / roll angle of the fuselage and the target pitch angle / target roll angle, a fuselage balance control algorithm corresponding to the shooting mode is used to calculate the control amount of the fuselage balance actuator. The specific algorithm is as follows:

[0112] Set T0 as the moment when the drone working mode switches to shooting mode, T0 as the starting time point of this round of control, and set A_FIT p is the current fuselage pitch angle A p and A_FIT r is the current fuselage roll angle Ar , A_FIT p and A_FIT r It is the target pitch angle and target roll angle of the fuselage balance target to be controlled in this round. The control algorithm is the cascade PID algorithm;

[0113]

[0114] Formula (4) is the first-level PID formula, where A1_K p 、A1_K i are proportional and integral parameters;

[0115]

[0116] Formula (5) is the second-level PID formula, where A2_K p 、A2_K i 、A2_K d are proportional, integral, and differential parameters;

[0117] The first-level PID uses formula (4) to calculate the target pitch angle velocity C_AR to be controlled based on the deviation between the current pitch angle / current roll angle of the fuselage and the target pitch angle / target roll angle. p (k) and target roll angular velocity C_AR r (k); The second-level PID uses formula (5) to calculate the control quantities C_PITCH(k) and C_ROLL(k) of the fuselage balance actuator according to the deviation between the current pitch angular velocity / current roll angular velocity of the fuselage and the target pitch angular velocity / target roll angular velocity;

[0118] Step S204: Control the action of the fuselage balancing actuator according to the calculated control amount: If C_PITCH(k) is a negative number, the guide vane of the fuselage balancing actuator 320 opens an angle |C_PITCH(k)|; the guide vane of the fuselage balancing actuator 310 rotates to fit the fuselage shell, and the upward tilting movement of the fuselage around the pitch axis is suppressed. If it is a positive number, the guide vane of the fuselage balancing actuator 320 rotates to fit the fuselage shell, and the guide vane of the fuselage balancing actuator 310 opens an angle |C_PITCH(k)|, and the downward tilting movement of the fuselage around the pitch axis is suppressed. If it is 0, the guide vanes of the fuselage balancing actuators (310, 320) are all rotated to fit the fuselage shell, and no torque is output.

[0119] If C_ROLL(k) is a negative number, the guide vanes of the fuselage balancing actuator 330 are opened at an angle |C_ROLL(k)|, and the guide vanes of the fuselage balancing actuator 340 are rotated to be perpendicular to the rotor disc, thereby suppressing the tilting movement of the fuselage around the roll axis to the lower right (where the Y-axis arrow points); if it is a positive number, the guide vanes of the fuselage balancing actuator 330 are rotated to be perpendicular to the rotor disc, and the guide vanes of the fuselage balancing actuator 340 are opened at an angle |C_ROLL(k)|, thereby suppressing the tilting movement of the fuselage around the roll axis to the lower left; if it is 0, the guide vanes of the fuselage balancing actuators (330, 340) are both rotated to be perpendicular to the rotor disc, and no torque is output.

[0120] Among them, |X| is the absolute value of X;

[0121] Step S205: Go to step S202 to execute the next control cycle.

[0122] Understandably, Fig.14 The fuselage balance control method shown can be applied to any fuselage balance UAV described in the first to third embodiments. In specific implementation, different working modes and corresponding fuselage balance control targets can be set according to the application field requirements of different UAVs. Only one working mode or more working modes can be set. In a specific working mode, only the roll motion or pitch motion of the fuselage can be controlled. For example, for Fig.11 and Fig.12 The panoramic shooting drone shown in the figure can be used for panoramic shooting of large-scale activities. In this application scenario, the drone needs to shoot stable panoramic images throughout the whole process. Therefore, only one working mode is set, namely the shooting mode, and the corresponding fuselage balance control target is that the target pitch angle and target roll angle of the fuselage are both 0°. Step S203 of the balance control method of the drone only corresponds to the content of the shooting mode.

[0123] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuselage-balanced drone, characterized in that: include: body; Rotor bracket; A lift device mounted on the rotor bracket, wherein the lift device comprises a rotor; A rotor tilt device installed on the fuselage and used to rotate the rotor bracket to control the inclination angle of the rotor; at least one fuselage balancing actuator for outputting a moment causing the fuselage to produce a tilting motion; as well as A fuselage balancing controller for controlling the action of the fuselage balancing actuator to keep the fuselage balanced; The fuselage is a hollow frame structure, the rotor tilt device and the lift device are placed inside the fuselage, and multiple cameras are arranged around the fuselage to shoot 720° panoramic images, wherein the cameras are respectively arranged on the top and bottom of the fuselage; At least one of the fuselage balancing actuators is a fuselage balancing actuator for outputting a moment causing the fuselage to undergo a pitching motion; And / or, the two fuselage balancing actuators are fuselage balancing actuators for outputting a torque causing the fuselage to undergo a pitch motion, and the two fuselage balancing actuators are respectively arranged on both sides of the pitch axis of the fuselage balancing UAV; and / or, at least one of the fuselage balancing actuators is a fuselage balancing actuator for outputting a moment causing the fuselage to undergo a rolling motion; And / or, the two fuselage balancing actuators are fuselage balancing actuators for outputting a torque causing the fuselage to roll, and the two fuselage balancing actuators are respectively arranged on both sides of the roll axis of the fuselage balanced UAV; And / or, at least one of the fuselage balancing actuators includes a balancing guide vane and a balancing servo, wherein the balancing guide vane is installed under the rotor, and utilizes the downwash airflow of the rotor to generate a torque causing the fuselage to tilt, and the balancing servo controls the rotation of the balancing guide vane to adjust the angle of the balancing guide vane relative to the downwash airflow of the rotor, and controls the magnitude of the torque generated by the balancing guide vane; one surface of the balancing guide vane faces the downwash airflow of the rotor, and utilizes the pressure formed on the surface by the downwash airflow of the rotor to generate a torque causing the fuselage to tilt.

2. The fuselage-balanced UAV according to claim 1, characterized in that: The rotor tilt device includes a first rotating mechanism, a first rotating controller, an adapter bracket, a second rotating mechanism and a second rotating controller; the rotor bracket is rotationally connected to the adapter bracket via the first rotating mechanism, and the adapter bracket is rotationally connected to the fuselage via the second rotating mechanism, and the rotation axis of the first rotating mechanism and the rotation axis of the second rotating mechanism are not parallel; the first rotating controller is used to control the rotation of the rotor bracket around the rotation axis of the first rotating mechanism, and the second rotating controller is used to control the rotation of the adapter bracket around the rotation axis of the second rotating mechanism, thereby controlling the rotation of the rotor around the rotation axes of the first rotating mechanism and the second rotating mechanism, thereby realizing the tilt angle control of the rotor.

3. The fuselage-balanced UAV according to claim 2, characterized in that: The rotor tilt device further includes a third rotating mechanism, and the two ends of the adapter bracket are rotatably connected to the fuselage through the second rotating mechanism and the third rotating mechanism respectively, and the second rotating mechanism coincides with the rotation axis of the third rotating mechanism; Alternatively, the rotor tilt device also includes a third rotating mechanism and a fourth rotating mechanism, and the two ends of the rotor bracket are rotationally connected to the adapter bracket through the first rotating mechanism and the third rotating mechanism respectively, and the rotation axes of the first rotating mechanism and the third rotating mechanism coincide; the two ends of the adapter bracket are rotationally connected to the fuselage through the second rotating mechanism and the fourth rotating mechanism respectively, and the rotation axes of the second rotating mechanism and the fourth rotating mechanism coincide.

4. The fuselage-balanced UAV according to claim 1, characterized in that: It also includes a rotor protection frame installed on the rotor bracket, the rotor protection frame is a hollow structure, the rotor is placed inside the rotor protection frame, and the rotor protection frame is used to protect the rotor.

5. The fuselage-balanced UAV according to any one of claims 1 to 4, characterized in that: The balancing guide plate can be rotated to a position that does not affect the folding and recovery of the fuselage balance drone.

6. The fuselage-balanced UAV according to any one of claims 1 to 4, characterized in that: At least one of the fuselage balancing actuators is a fan, which is arranged on the fuselage. The thrust of the fan generates a torque that causes the fuselage to tilt, and the fan speed is controlled to adjust the torque.

7. The fuselage-balanced UAV according to any one of claims 1 to 4, characterized in that: The fuselage includes a first body and at least one arm, the first body is a long strip structure, the arm is arranged at the end of the first body, the rotor tilt device is installed on the arm, and the lift device is placed in the space surrounded by the arm and the first body to realize the folding and recovery of the fuselage-balanced drone.

8. A fuselage balance control method for a fuselage balancing UAV according to any one of claims 1 to 7, comprising the following steps: Step S1, setting at least one working mode for the fuselage balancing drone, and setting a fuselage balancing control target for each working mode; Step S2, the fuselage balance controller receives input data required for balance control; Step S3, the fuselage balancing controller calculates the control amount of the fuselage balancing actuator according to the current working mode of the fuselage balancing UAV, the input data in step S2 and the fuselage balancing target in step S1 corresponding to the current working mode; Step S4, controlling the action of the fuselage balancing actuator according to the control amount; Step S5, looping through steps S2 to S4 to make the fuselage posture meet the fuselage balance control target.

9. The fuselage balance control method according to claim 8, characterized in that: In step S1, one of the working modes is a flight mode, which corresponds to a working state in which the fuselage balancing drone has no image shooting task. The fuselage balancing control target set in this working mode is that the roll angular velocity of the fuselage is lower than a roll angular velocity threshold, and / or the pitch angular velocity of the fuselage is lower than a pitch angular velocity threshold.

10. The control method according to claim 8, characterized in that: In step S1, one of the working modes is a shooting mode, and the shooting mode corresponds to a working state in which the fuselage balancing drone has an image shooting task. The fuselage balancing control target set in this working mode is that the pitch angle of the fuselage is equal to the target pitch angle, and / or the roll angle of the fuselage is equal to the target roll angle, wherein the target pitch angle and the target roll angle are respectively the pitch angle and the roll angle of the fuselage balancing drone when it switches to this working mode.

11. The control method according to claim 8, characterized in that: In step S2, the input data includes fuselage attitude data, and the fuselage attitude data includes a current pitch angle, a current pitch angle velocity, a current roll angle, and a current roll angle velocity of the fuselage.

12. The control method according to claim 8, characterized in that: In step S3, a corresponding fuselage balance control target is applied according to the current working mode of the fuselage balance UAV, and a corresponding fuselage balance control algorithm is executed; the fuselage balance control algorithm calculates the control amount of the fuselage balance actuator according to the deviation between the current value of the fuselage posture and the target value set by the fuselage balance control target.

Images