A method and device for controlling the airflow intensity of a crop protection unmanned aerial vehicle

Abstract

The application discloses a kind of control method and device for the airflow intensity of plant protection unmanned aerial vehicle rotor, and the airflow under the rotor of plant protection unmanned aerial vehicle is adjusted by execution module arranged below the rotor, and the control method comprises the following steps: according to the wind speed that crop can bear and will not be damaged, the target wind speed of the airflow of plant protection unmanned aerial vehicle rotor is set;Plant protection unmanned aerial vehicle operating height, plant protection unmanned aerial vehicle horizontal flight speed, plant protection unmanned aerial vehicle height variation acceleration and plant protection unmanned aerial vehicle inclination angle are obtained;Corrected wind speed is calculated;Sensor wind speed is obtained;Sensor wind speed is compared with corrected wind speed;Execution module operates according to comparison result.The method can weaken the airflow intensity under the rotor of plant protection unmanned aerial vehicle with less power loss through passive rotating blade, prevent crop from being damaged and lodging, and improve the operation effect of plant protection unmanned aerial vehicle.

Description

Technical Field

[0001] This invention relates to the field of plant protection technology using unmanned aerial vehicles (UAVs), specifically to a method and device for controlling the airflow intensity of the rotor of a plant protection UAV. Background Technology

[0002] Drones have seen rapid application and development in recent years, with agricultural drones dominating agricultural aviation technology. Previously, agricultural drones suffered from problems such as short flight time and small payload capacity. With continuous advancements in drone technology, the flight time and payload capacity of agricultural drones have been continuously improved, enabling their application in more agricultural production.

[0003] As the range and payload of agricultural drones increase, their weight also increases. Drones rely on rotors for lift, and to increase lift, the rotor size is getting larger and larger. The airflow intensity under the rotor is also increasing. Excessive airflow intensity can damage crops and even cause lodging and yield reduction. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned problems and provide a method for controlling the airflow intensity of the rotor of an agricultural drone. This method can reduce the airflow intensity below the rotor of the agricultural drone by passively rotating blades with minimal power loss, thereby preventing crop damage and lodging and improving the operational efficiency of the agricultural drone.

[0005] Another objective of this invention is to provide a control device for the airflow intensity of the rotor of an agricultural drone.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A method for controlling the airflow intensity of a plant protection drone rotor, wherein the control method adjusts the airflow below the rotor of the plant protection drone through an actuator module disposed below the rotor. The airflow below the rotor causes the blades of the actuator module to rotate passively. The control method includes the following steps:

[0008] (S1) Set the target wind speed of the rotor airflow of the agricultural drone according to the wind speed that the crop can withstand without being damaged.

[0009] (S2) Acquire the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the altitude change acceleration of the agricultural drone, and the tilt angle of the agricultural drone detected by the sensor;

[0010] (S3) The corrected wind speed is calculated based on the relationship between the target wind speed and the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the acceleration of the altitude change of the agricultural drone, and the tilt angle of the agricultural drone.

[0011] (S4) Obtain the sensor wind speed, which is the real-time wind speed of the airflow from the rotor of the agricultural drone detected by the sensor; compare the sensor wind speed with the corrected wind speed.

[0012] (S5) The execution module performs the following operations based on the comparison results:

[0013] When the current wind speed of the airflow under the rotor of the agricultural drone is greater than the corrected wind speed, the blade angle of attack of the execution module is adjusted to increase the blade angle of attack, increase the rotation speed of the blades, and the airflow spreads in all directions, reducing the wind speed below the rotor of the agricultural drone.

[0014] When the current wind speed of the rotor airflow of the agricultural drone is less than the corrected wind speed, the blade angle of attack of the execution module is adjusted to reduce the blade angle of attack, slow down the rotation speed of the blades, reduce the degree of airflow diffusion in all directions, and reduce the power loss of the agricultural drone.

[0015] When the current wind speed of the airflow from the rotor of the agricultural drone is equal to the corrected wind speed, the execution module does not make any adjustments.

[0016] In the above-mentioned method for controlling the rotor airflow intensity of agricultural drones, the wind speed detected by the sensor is not the actual wind speed experienced by the crop, but rather the wind speed at the sensor's location. When the flight altitude is relatively high, the distance between the sensor and the crop is relatively large, and the wind speed will decrease after traveling a long distance, resulting in the wind speed detected by the sensor being greater than the target wind speed. If the agricultural drone is in motion, the wind speed detected by the sensor is also greater than the target wind speed. Therefore, it is necessary to correct the wind speed for precise control.

[0017] In a preferred embodiment of the present invention, in step (S3), the relationship between the target wind speed and the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the acceleration due to altitude change of the agricultural drone, and the tilt angle of the agricultural drone is as follows:

[0018] The higher the operating altitude of an agricultural drone, the higher the corrected wind speed will be compared to the target wind speed; the higher the horizontal flight speed of an agricultural drone, the higher the corrected wind speed will be compared to the target wind speed; when the altitude of an agricultural drone decreases, the greater the acceleration of the downward change in altitude, the lower the corrected wind speed will be compared to the target wind speed; the greater the tilt angle of an agricultural drone, the lower the corrected wind speed will be compared to the target wind speed.

[0019] A device for controlling the airflow intensity of a plant protection drone rotor includes a controller, a sensor, and an execution module. The controller is connected to the sensor and the execution module. The execution module is installed below the rotor motor of the plant protection drone. The rotor motor drives the rotor of the plant protection drone to rotate. The execution module adds tangential velocity to the airflow in a rotating manner, causing the airflow to spread in all directions to increase the coverage area of ​​the airflow from the rotor of the plant protection drone, thereby reducing the airflow speed.

[0020] The working principle of the above-mentioned control device for the rotor airflow intensity of agricultural drones is as follows:

[0021] The sensors are used to detect the operating altitude of the agricultural drone, its horizontal flight speed, the acceleration due to altitude change, its tilt angle, and the wind speed of the airflow over its rotor. The rotational speed control of the device in this invention is related to the horizontal flight speed, the overall mass, and the real-time rotational speed of the agricultural drone. The wind speed data of the airflow over the rotor of the agricultural drone detected by the sensors is used as the detection value and fed back to the controller to adjust the control device. Specifically, when the agricultural drone is operating, the airflow under the rotor causes the blades of the execution module to rotate passively. By comparing the sensor wind speed with the corrected wind speed, the angle of attack of the blades is adjusted to reduce the power loss of the agricultural drone and weaken the intensity of the airflow over the rotor.

[0022] Preferably, the sensors include an attitude sensor based on the agricultural drone's own flight controller, a rotor motor speed sensor, and a wind speed sensor. The attitude sensor is used to acquire the agricultural drone's operating altitude, horizontal flight speed, altitude change acceleration, and tilt angle. The rotor motor speed sensor is used to detect changes in the rotor speed of the agricultural drone. The wind speed sensor is used to detect the wind speed of the airflow beneath the rotor of the agricultural drone. In the above structure, the rotor motor drives the rotor (i.e., propeller) of the agricultural drone to rotate. Therefore, the rotor motor speed sensor can detect changes in the rotor speed of the agricultural drone, and the wind speed sensor can detect the real-time wind speed of the airflow beneath the rotor of the agricultural drone, specifically the real-time wind speed of the airflow below the rotor of the agricultural drone.

[0023] Preferably, the execution module includes a rotating mechanism disposed at the bottom of the rotor motor, a differential positioning mechanism disposed on the rotating mechanism, blades disposed on the differential positioning mechanism, and a drive mechanism for driving the differential positioning mechanism to move and change the angle and position of the blades. In the above structure, the blades are passively rotated by the airflow from the rotor of the agricultural drone. The differential positioning mechanism, the blades, and the drive mechanism rotate together. The drive mechanism can drive the differential positioning mechanism to move, thereby changing the angle and position of the blades. The angle of the blades includes the sweep angle and the angle of attack. The angle of attack of the blades can be flexibly adjusted according to the corrected wind speed.

[0024] Preferably, the rotating mechanism includes a rotating base and a rotating slide rail disposed on the rotating base; the rotating base is connected to the rotor motor via a mounting bracket, the mounting bracket being fixed to the bottom of the rotor motor, and the rotating base being rotatably connected to the mounting bracket. The mounting bracket facilitates the installation of the rotating base and also facilitates connection to the bottom of the rotor motor.

[0025] Preferably, the differential positioning mechanism includes multiple differential rings, all of which are sleeved on the rotating slide rail. The differential rings are slidably connected to the rotating slide rail along its axial direction. The multiple differential rings include an upper sweep angle differential ring, a lower sweep angle differential ring, and at least one angle-of-attack differential ring. A connecting rod assembly is provided between the upper sweep angle differential ring and the lower sweep angle differential ring. The connecting rod assembly includes an upper connecting rod and a lower connecting rod. One end of the upper connecting rod is hinged to the upper sweep angle differential ring, one end of the lower connecting rod is hinged to the lower sweep angle differential ring, and the other end of the upper connecting rod is hinged to the other end of the lower connecting rod. The blade is mounted on the upper connecting rod. The angle-of-attack differential ring and the blade are connected by a draw wire. In the above structure, the drive mechanism drives the differential ring to move along the rotating slide rail. When the distance between the upper and lower differential rings changes, the angle between the upper and lower connecting rods also changes, which in turn changes the sweep angle of the blade. Specifically, when the distance between the upper and lower differential rings increases, the blade is closer to the rotating slide rail, and the sweep angle is smaller; when the distance between the upper and lower differential rings decreases, the blade is further away from the rotating slide rail, and the sweep angle is smaller. By changing the sweep angle, the equivalent diameter is changed to accommodate different sizes of agricultural drone rotors (propellers), improving the applicability of the execution module. When the angle-of-attack differential ring moves along the rotating slide rail, it pulls the pull line, which pulls the blade, causing the blade to rotate and thus changing the angle of attack of the blade.

[0026] Preferably, the drive mechanism includes multiple sets of drive components, each set corresponding to one differential ring. Each drive component includes a drive motor housed inside the rotating base, a drive pulley mounted on the main shaft of the drive motor, a driven pulley located at the lower end of the rotating slide rail, and a transmission belt connecting the drive pulley and the driven pulley. The transmission belt is connected to the differential ring. In this structure, the transmission belt of each drive component is connected to one differential ring. The drive motor drives the transmission belt, thereby realizing the movement of the differential ring. Multiple drive motors control the movement of multiple differential rings, allowing for flexible control of the differential rings.

[0027] Preferably, the execution module further includes a speed limiting mechanism, which comprises a plurality of centrifugal friction plates disposed inside the rotating base. When the rotational speed of the rotating mechanism is too high, the centrifugal friction plates inside the rotating base are thrown out and pressed against the inner wall of the mounting base, generating frictional damping and limiting the rotational speed of the rotating mechanism.

[0028] Preferably, the upper connecting rod is provided with a protruding shaft, and the blade is rotatably connected to the protruding shaft; the protruding shaft has a hollow internal structure; the blade includes a winglet, a flexible skin, and a wing assembly, the winglet is rotatably mounted on the protruding shaft, the winglet has a connecting hole, and the connecting hole is connected to one of the angle-of-attack differential rings via a cable; the wing assembly includes a rotating spar and wing ribs; wherein, the rotating spar is rotatably connected to the protruding shaft, the wing ribs are fixedly mounted on the rotating spar, and the flexible skin covers the wing ribs; the rotating spar... A first transmission mechanism is provided between the pull wire and the shaft. The first transmission mechanism includes a rotating shaft plunger, a cylindrical protrusion, a straight groove, an inclined groove, and a return spring. The rotating shaft plunger is disposed inside the protruding shaft and is connected to another angle-of-attack differential ring via the pull wire. The cylindrical protrusion is disposed on the rotating shaft plunger, the straight groove is disposed on the protruding shaft, and the inclined groove is disposed on the rotating wing beam. The cylindrical protrusion is engaged with the straight groove and the inclined groove. The return spring is disposed inside the protruding shaft and is used to reset the rotating shaft plunger. In the above structure, the rotating spar can rotate but cannot move axially. The straight slot is outside the inclined slot. Under the action of the cylindrical protrusion and the straight slot, the rotating shaft plug can only move along the axial direction of the protruding shaft and cannot rotate. When the rotating shaft plug moves, the cylindrical protrusion also moves on the straight slot. The cylindrical protrusion applies pressure to the inclined slot, forcing the rotating spar to deflect, thereby driving the rib to rotate. Through the movement of the angle of attack differential ring, the pull wire is pulled to move, thereby driving the wing assembly and / or the blade to rotate, realizing the adjustment of the blade's angle of attack.

[0029] Preferably, the blade has a segmented structure, and the wing assembly has multiple sets. The rotating spars in the multiple sets of wing assemblies are connected end to end. The interior of the rotating spar is a hollow structure, and a second transmission mechanism is provided between two adjacent rotating spars. The specific structure of the second transmission mechanism is the same as that of the first transmission mechanism. The straight slot of the second transmission mechanism is provided on one of the rotating spars, and the inclined slot of the second transmission mechanism is provided on the other rotating spar. That is, one end of a rotating spar has a straight slot, and the other end has an inclined slot. All the outer surfaces of the ribs are covered with a layer of the flexible skin. One set of wing assemblies corresponds to one angle-of-attack differential ring, and the number of angle-of-attack differential rings is equal to the number of wing assemblies plus the number of blades. Through multiple angle-of-attack differential rings, the angle of attack of the blades and wing assemblies is controlled, that is, the angle of attack of each segment of the blade is individually controllable.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] 1. The method for controlling the airflow intensity of the rotor of the plant protection drone in this invention can reduce the airflow intensity under the rotor of the plant protection drone, and prevent crop damage and lodging due to excessive airflow intensity during operation.

[0032] 2. The method for controlling the airflow intensity of the plant protection drone rotor in this invention involves the blades passively rotating within the airflow of the plant protection drone rotor, rather than blocking the airflow. Therefore, the lift loss of the plant protection drone is small.

[0033] 3. The control device for the airflow intensity of the rotor of the agricultural drone in this invention allows for adjustment of the vertical distance, angle of attack, and sweep angle of the blades, thus making it applicable to different models of agricultural drones and highly versatile.

[0034] 4. The control device for the airflow intensity of the rotor of the plant protection drone in this invention has a segmented blade structure, and the angle of attack of each segment of the blade can be adjusted, which can realize the local adjustment of the airflow intensity. Attached Figure Description

[0035] Figure 1 This is a control flowchart of a method for controlling the airflow intensity of a plant protection drone rotor in this invention.

[0036] Figure 2 This is a structural block diagram of a control device for the airflow intensity of a plant protection drone rotor according to the present invention.

[0037] Figure 3 This is a schematic diagram of the control device of the present invention installed on an agricultural drone.

[0038] Figure 4 This is a three-dimensional structural diagram of the execution module in this invention.

[0039] Figure 5 This is the main view of the execution module in this invention.

[0040] Figure 6 for Figure 5 A magnified view of a portion of point A in the middle.

[0041] Figure 7 This is a three-dimensional structural diagram of the blades of the execution module in this invention under different sweep angle states.

[0042] Figure 8 This is a schematic diagram showing the installation of the rotating slide rail, rotating base, speed limiting mechanism, and drive mechanism in this invention.

[0043] Figure 9 This is a schematic diagram showing the installation of the rotating slide rail, differential ring, and part of the drive mechanism in this invention.

[0044] Figure 10 This is a partial installation diagram of the rotating slide rail and differential ring in this invention.

[0045] Figure 11 This is a schematic diagram of the internal structure of the mounting base in this invention.

[0046] Figure 12 This is a three-dimensional structural diagram of the blade in this invention.

[0047] Figure 13 This is a three-dimensional structural diagram of the blade with hidden flexible skin in this invention.

[0048] Figure 14 This is a schematic diagram showing the installation of the upper connecting rod, protruding shaft, part of the wing assembly, and the first transmission mechanism in this invention.

[0049] Figure 15 This is an exploded view of the upper connecting rod, protruding shaft, wing assembly, and first transmission mechanism in this invention.

[0050] Figure 16 This is an exploded view of two adjacent wing assemblies and the second transmission mechanism in this invention. Detailed Implementation

[0051] To enable those skilled in the art to fully understand the technical solutions of the present invention, the present invention will be further described below in conjunction with embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0052] See Figures 1-4 This embodiment discloses a method for controlling the airflow intensity of a plant protection drone rotor, including the following steps:

[0053] (S1) Set the target wind speed of the rotor airflow of the agricultural drone according to the wind speed that the crop can withstand without being damaged.

[0054] (S2) Acquire the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the altitude change acceleration of the agricultural drone, and the tilt angle of the agricultural drone detected by the sensor;

[0055] (S3) The corrected wind speed is calculated based on the relationship between the target wind speed and the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the acceleration of the altitude change of the agricultural drone, and the tilt angle of the agricultural drone.

[0056] (S4) Obtain the sensor wind speed, which is the real-time wind speed of the airflow from the rotor of the agricultural drone detected by the sensor; compare the sensor wind speed with the corrected wind speed.

[0057] (S5) The execution module 100 performs the following operations based on the comparison results:

[0058] When the current wind speed (sensor wind speed) of the rotor airflow of the agricultural drone is greater than the corrected wind speed, the angle of attack of the blade 1 of the execution module 100 is adjusted to increase the angle of attack of the blade 1, thereby increasing the rotation speed of the blade 1. The airflow spreads in all directions, and the wind speed below the rotor of the agricultural drone decreases, that is, the wind speed at the crop position below the rotor of the agricultural drone decreases accordingly.

[0059] When the current wind speed (sensor wind speed) of the rotor airflow of the agricultural drone is less than the corrected wind speed, the angle of attack of the blade 1 of the execution module 100 is adjusted to reduce the angle of attack of the blade 1, slow down the rotation speed of the blade 1, reduce the degree of airflow diffusion in all directions, and reduce the power loss of the agricultural drone.

[0060] When the current wind speed (sensor wind speed) of the rotor airflow of the agricultural drone is equal to the corrected wind speed, the execution module 100 does not make any adjustments.

[0061] See Figure 1 In the above-mentioned method for controlling the airflow intensity of the rotor of the agricultural drone, the wind speed of the airflow at the crop position below the rotor 200 of the agricultural drone can be controlled to within the target wind speed.

[0062] See Figures 1-3 In the above-mentioned method for controlling the airflow intensity of the rotor of an agricultural drone, the wind speed detected by the sensor is not the actual wind speed experienced by the crop, but the wind speed at the location of the sensor. When the flight altitude is relatively high, the distance between the sensor and the crop is relatively large, and the wind speed will decrease after the rotor airflow travels a long distance, so the wind speed detected by the sensor will be greater than the target wind speed. If the agricultural drone is in motion, the wind speed detected by the sensor will also be greater than the target wind speed. Therefore, it is necessary to correct the wind speed for precise control.

[0063] See Figures 1-3 In step (S3), the relationship between the target wind speed and the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the acceleration due to altitude change of the agricultural drone, and the tilt angle of the agricultural drone is as follows:

[0064] The higher the operating altitude of the agricultural drone, the higher the corrected wind speed will be compared to the target wind speed; the higher the horizontal flight speed of the agricultural drone, the higher the corrected wind speed will be compared to the target wind speed; when the altitude of the agricultural drone decreases, the corrected wind speed will be lower than the target wind speed, the greater the acceleration of the downward change in altitude of the agricultural drone, the lower the corrected wind speed will be compared to the target wind speed; the greater the tilt angle of the agricultural drone, the lower the corrected wind speed will be compared to the target wind speed.

[0065] In step (S3), the specific calculation method for the corrected wind speed is based on the empirical formula obtained from the experiment, which is:

[0066]

[0067] Where Vx is the corrected wind speed, Vc is the target wind speed, a is the weight of the plant protection drone's operating altitude, b is the weight of the plant protection drone's altitude change acceleration, c is the weight of the plant protection drone's tilt angle, d is the weight of the plant protection drone's horizontal flight speed, f(x) is the fitting function of the relationship between the plant protection drone's operating altitude and wind speed, f(y) is the fitting function of the relationship between the plant protection drone's altitude-direction acceleration and wind speed, f(z) is the fitting function of the relationship between the plant protection drone's tilt angle and wind speed, and f(v) is the fitting function of the relationship between the plant protection drone's horizontal flight speed and wind speed.

[0068] See Figures 2-4 This embodiment discloses a control device for the airflow intensity of a plant protection drone rotor, including a controller, a sensor, and an execution module 100. The controller is connected to the sensor and the execution module. The execution module 100 is installed below the rotor motor of the plant protection drone. The rotor motor drives the rotor 200 of the plant protection drone to rotate. The execution module 100 adds tangential velocity to the airflow in a rotating manner, causing the airflow to spread in all directions to increase the coverage area of ​​the airflow of the plant protection drone rotor, thereby reducing the airflow speed.

[0069] See Figures 2-4 The working principle of the control device for the rotor airflow intensity of the above-mentioned agricultural drone is as follows:

[0070] The sensors are used to detect the operating altitude of the agricultural drone, its horizontal flight speed, the acceleration due to altitude change, its tilt angle, and the wind speed of the airflow from its rotor. In this embodiment, the rotation speed control of the control device is related to the horizontal flight speed, the overall mass, and the real-time rotation speed of the agricultural drone. The wind speed data of the airflow from the rotor of the agricultural drone detected by the sensors is used as the detection value and fed back to the controller to adjust the control device. Specifically, when the agricultural drone is operating, the airflow below the rotor 200 causes the blades 1 of the execution module 100 to rotate passively. By comparing the sensor wind speed with the corrected wind speed, the angle of attack of the blades 1 is adjusted to reduce the power loss of the agricultural drone and weaken the intensity of the airflow from its rotor.

[0071] See Figures 2-4 The sensors include an attitude sensor based on the agricultural drone's own flight controller, a rotor motor speed sensor, and a wind speed sensor. The attitude sensor is used to acquire the agricultural drone's operating altitude, horizontal flight speed, altitude change acceleration, and tilt angle. The rotor motor speed sensor is used to detect changes in the rotor speed of the agricultural drone. The wind speed sensor is used to detect the wind speed of the airflow above the agricultural drone's rotor. In the above structure, the rotor motor drives the agricultural drone's rotor (i.e., propeller) to rotate. Therefore, the rotor motor speed sensor can detect changes in the rotor speed of the agricultural drone, and the wind speed sensor can detect the real-time wind speed of the airflow below the agricultural drone's rotor, specifically the real-time wind speed of the airflow below the agricultural drone's rotor, that is, the wind speed of the airflow below the agricultural drone's rotor at the location of the wind speed sensor.

[0072] See Figures 2-4 The execution module 100 includes a rotating mechanism located at the bottom of the rotor motor, a differential positioning mechanism mounted on the rotating mechanism, blades 1 mounted on the differential positioning mechanism, and a drive mechanism for driving the differential positioning mechanism to change the angle and position of the blades 1. In this structure, the blades are passively rotated by the airflow from the rotor of the agricultural drone. The differential positioning mechanism, blades 1, and drive mechanism rotate together. The drive mechanism can drive the differential positioning mechanism to move, thereby changing the angle and position of the blades 1. The angle of the blades 1 includes the sweep angle and the angle of attack. The angle of attack of the blades 1 can be flexibly adjusted according to the corrected wind speed. The wind speed sensor is located below the blades 1. After the airflow below the rotor of the agricultural drone is adjusted by the blades 1, the intensity of the airflow below the rotor of the agricultural drone is reduced.

[0073] See Figures 3-11The rotating mechanism includes a rotating base 2 and a rotating slide rail 3 mounted on the rotating base 2. Specifically, the lower end of the rotating base 2 is fixedly connected to the upper end of the rotating slide rail 3. The rotating base 2 is connected to the rotor motor via a mounting base 4, which is fixed to the bottom of the rotor motor, and the rotating base 2 is rotatably connected to the mounting base 4. The mounting base 4 facilitates the installation of the rotating base 2 and also facilitates its connection to the bottom of the rotor motor.

[0074] See Figure 8 and Figure 11 A slip ring 5 is provided between the rotating base 2 and the mounting base 4 for leading out the power line and control line of the rotor motor.

[0075] join Figures 3-16The differential displacement mechanism includes multiple differential rings 6, all of which are sleeved on the rotating slide rail 3. The differential rings 6 are slidably connected to the rotating slide rail 3 along the axial direction of the rotating slide rail 3. The multiple differential rings 6 include an upper sweep angle differential ring 61, a lower sweep angle differential ring 62, and at least one angle-of-attack differential ring 63. A connecting rod assembly is provided between the upper sweep angle differential ring 61 and the lower sweep angle differential ring 62. The connecting rod assembly includes an upper connecting rod 7 and a lower connecting rod 8. One end of the upper connecting rod 7 is hinged to the upper sweep angle differential ring 61, one end of the lower connecting rod 8 is hinged to the lower sweep angle differential ring 62, and the other end of the upper connecting rod 7 is hinged to the other end of the lower connecting rod 8. The blade 1 is mounted on the upper connecting rod 7. The angle-of-attack differential ring 63 and the blade 1 are connected by a draw wire. In the above structure, the drive mechanism drives the differential ring 6 to move along the rotating slide rail 3. When the distance between the upper differential ring 61 and the lower differential ring 62 changes, the angle between the upper connecting rod 7 and the lower connecting rod 8 also changes, thereby changing the sweep angle of the blade 1. Specifically, when the distance between the upper differential ring 61 and the lower differential ring 62 increases, the blade 1 is closer to the rotating slide rail 3, and the sweep angle is smaller; when the distance between the upper differential ring 61 and the lower differential ring 62 decreases, the blade 1 is further away from the rotating slide rail 3, and the sweep angle is smaller. By changing the sweep angle, the equivalent diameter is changed to adapt to different sizes of agricultural drones. The rotor 200 (propeller) improves the applicability of the execution module. When the angle-of-attack differential ring 63 moves along the rotating slide rail 3, it pulls the cable, which in turn pulls the blade 1, causing the blade 1 to rotate and thus changing its angle of attack. When the positions of the upper sweep angle differential ring 61 and the lower sweep angle differential ring 62 remain unchanged, the angle-of-attack differential ring 63 moves upward, increasing the distance between the angle-of-attack differential ring 63 and the upper and lower sweep angle differential rings 61 and 62. This pulls the cable, causing the blade 1 to rotate and thus changing its angle of attack. Specifically, in this embodiment, when the angle-of-attack differential ring 63 moves upward, the angle of attack of the blade 1 increases; when it moves downward, the angle of attack of the blade 1 decreases. In other embodiments, when the angle-of-attack differential ring 63 moves upward, the angle of attack of the blade 1 decreases; when it moves downward, the angle of attack of the blade 1 increases. The specific direction is determined by the orientation of the airfoil of the blade 1.

[0076] See Figure 10 The differential ring 6 has a groove 601 inside, and the rotating slide rail 3 has a protrusion 301. The protrusion 301 cooperates with the groove 601 to realize the up and down movement of the differential ring 6 on the rotating slide rail 3 and the rotation together with the rotating slide rail 3.

[0077] See Figure 4 Each execution module has three blades 1, and correspondingly, there are also three sets of connecting rod assemblies. The differential ring 6 is provided with mounting holes for mounting connecting rod assemblies or pull wires, and the pull wires are steel wires.

[0078] See Figures 4-9 The drive mechanism includes multiple sets of drive components, each set corresponding to one differential ring 6. Each drive component includes a drive motor 9 housed inside the rotating base 2, a drive pulley 10 mounted on the main shaft of the drive motor 9, a driven pulley 11 mounted at the lower end of the rotating slide rail 3, and a transmission belt 12 connecting the drive pulley 10 and the driven pulley 11. The transmission belt 12 is connected to the differential ring 6. In this structure, the transmission belt 12 of each drive component is connected to one differential ring 6. The drive motor 9 drives the transmission belt 12, thereby realizing the movement of the differential ring 6. Multiple drive motors 9 control the movement of multiple differential rings 6, allowing for flexible control of the differential rings 6.

[0079] See Figure 6 , Figure 8 and Figure 11 The execution module further includes a speed limiting mechanism, which comprises multiple centrifugal friction plates 13 disposed inside the rotating base 2, the multiple centrifugal friction plates 13 being distributed along the circumferential direction. When the rotational speed of the rotating mechanism is too high, the centrifugal friction plates 13 inside the rotating base 2 are thrown out and closely adhere to the inner wall of the mounting base 4, generating frictional damping and limiting the rotational speed of the rotating mechanism; the rotating base 2 is provided with holes for the centrifugal friction plates 13 to pass through, facilitating the centrifugal friction plates 13 to be thrown out and closely adhere to the inner wall of the mounting base 4.

[0080] See Figures 12-16The upper connecting rod 7 is provided with a protruding shaft 14, and the blade 1 is rotatably connected to the protruding shaft 14; the interior of the protruding shaft 14 is a hollow structure; the blade 1 includes a winglet 101, a flexible skin, and a wing assembly; the winglet 101 is rotatably mounted on the protruding shaft 14, and the winglet 101 is provided with a connecting hole 102, which is connected to one of the angle-of-attack differential rings 63 via a pull wire; the wing assembly includes a rotating spar 103 and a rib 104; wherein, the rotating spar 103 is rotatably connected to the protruding shaft 14, the rib 104 is fixedly mounted on the rotating spar 103, and the flexible skin covers the rib 104; a first transmission mechanism is provided between the rotating spar 103 and the pull wire, the first transmission... The moving mechanism includes a rotating shaft plunger 105, a cylindrical protrusion 106, a straight groove 107, an inclined groove 108, and a return spring 109. The rotating shaft plunger 105 is disposed inside the protruding shaft 14 and is connected to another angle-of-attack differential ring 63 via a pull wire. The cylindrical protrusion 106 is disposed on the rotating shaft plunger 105, the straight groove 107 is disposed on the protruding shaft 14, and the inclined groove 108 is disposed on the rotating wing beam 103. The cylindrical protrusion 106 is connected in conjunction with the straight groove 107 and the inclined groove 108. The return spring 109 is disposed inside the protruding shaft 14 and is used for the return of the rotating shaft plunger 105. The return spring 109 acts between the protruding shaft 14 and the rotating shaft plunger 105. In the above structure, the rotating spar 103 can rotate but cannot move axially. The straight slot 107 is outside the inclined slot 108. Under the action of the cylindrical protrusion 106 and the straight slot 107, the rotating shaft plug 105 can only move along the axial direction of the protruding shaft 14 and cannot rotate. When the rotating shaft plug 105 moves, the cylindrical protrusion 106 also moves on the straight slot 107. The cylindrical protrusion 106 applies pressure to the inclined slot 108, forcing the rotating spar 103 to deflect, thereby driving the rib 104 to rotate. Through the movement of the angle-of-attack differential ring 63, the pull wire is pulled, thereby driving the wing assembly and / or winglet 10. 1. Rotation to adjust the angle of attack of blade 1. Specifically, when the angle of attack differential ring 63 corresponding to blade 101 moves, it drives the cable to move. Under the traction of the cable, blade 101 rotates, thereby adjusting the angle of attack of blade 101. When the angle of attack differential ring 63 corresponding to the wing assembly moves, it drives the cable to move. Under the traction of the cable, it drives the rotating shaft plunger 105 to move, thereby rotating the wing assembly and adjusting the angle of attack of the wing assembly. The cable connected to blade 101 has strong rigidity. The angle of attack of blade 101 is adjusted by pushing and pulling the cable. Alternatively, a resettable spring can be set inside blade 101 for reset.

[0081] See Figures 12-16The blade 1 has a segmented structure. The wing assembly comprises multiple sets, with rotating spars 103 in each set connected end-to-end. The rotating spar 103 has a hollow interior, and a second transmission mechanism is provided between adjacent rotating spars 103. The specific structure of the second transmission mechanism is the same as that of the first transmission mechanism. The return spring 109 of the second transmission mechanism is located inside the rotating spar 103, and the straight slot 107 of the second transmission mechanism is located on one of the rotating spars 103. The inclined slot 108 is set on another rotating wing spar 103; that is, one end of a rotating wing spar 103 is provided with a straight slot 107 and the other end is provided with an inclined slot 108; all the outer surfaces of the wing ribs 104 and the winglets 101 are covered with a layer of the aforementioned flexible skin, and a set of wing assemblies corresponds to one angle of attack differential ring 63. The number of angle of attack differential rings 63 is equal to the number of wing assemblies plus the number of winglets 101; through multiple angle of attack differential rings 63, the angle of attack control of the winglets 101 and wing assemblies is realized, that is, the angle of attack of each segment of the blade 1 is individually controllable.

[0082] Specifically, the straight slot 107 of the second transmission mechanism is provided on the rotating wing beam 103 near the rotating slide rail 3, the inclined slot 108 of the second transmission mechanism is provided on the rotating wing beam 103 away from the rotating slide rail 3, and the rotating shaft plug 105 of the second transmission mechanism is connected to the angle of attack differential ring 63 by a pull wire.

[0083] See Figures 12-16 The first transmission mechanism and the second transmission mechanism each have two straight slots 107, two inclined slots 108, and two cylindrical protrusions 106, which are arranged symmetrically to ensure the smoothness of the movement.

[0084] See Figures 12-16 The upper connecting rod 7 is provided with a through hole 701, which communicates with the interior of the protruding shaft 14. The through hole is used for the routing of the pull wires. The pull wires controlling the wing assembly all enter through the through hole 701 and enter the interior of the rotating wing beam 103 to connect with the pivot sill 105. When the drive motor 9 drives the corresponding differential ring 6 to move, the pivot sill 105, under the traction of the pull wire, overcomes the elastic force of the return spring 109 and moves along the axial direction of the rotating wing beam 103. The cylindrical protrusion 106 applies pressure to the inclined slot 108 on the rotating wing beam 103, forcing the rotating wing beam 103 to deflect, thereby driving the wing rib 104 to rotate. When the drive motor 9 drives the corresponding differential ring 6 to move in the opposite direction, the pull wire is released, and the pivot sill 105 returns to its original position under the elastic force of the return spring 109, thereby causing the wing rib 104 to return to its original position.

[0085] See Figures 2-12The controller is mainly used for device speed control, flight status control, and flight weight control. The device speed control is the blade speed control. Specifically, the controller is connected to the attitude sensor, rotor motor speed sensor, wind speed sensor, and drive motor 9. The controller controls the drive motor 9 to control the angle of attack, sweep angle, and vertical position of the blade 1. The controller makes real-time adjustments based on the airflow intensity detected by the sensor.

[0086] See Figure 6 and Figure 13 In this embodiment, there are 5 differential rings 6, including one upper sweep differential ring 61, one lower sweep differential ring 62, and three angle-of-attack differential rings 63. There are two sets of wing assemblies. One set of wing assemblies is controlled by one angle-of-attack differential ring 63, and the remaining angle-of-attack differential ring 63 controls the wing flap 101.

[0087] See Figures 2-4 In this embodiment, there are multiple execution modules 100, the same number as the number of rotors 200 of the agricultural drone, and they are set in a one-to-one correspondence. In this embodiment, the number of execution modules and the number of rotors 200 of the agricultural drone are both 6. The execution modules 100 add tangential velocity to the airflow by rotating, so that the airflow spreads in all directions to increase the coverage area of ​​the airflow of the agricultural drone rotor. The air volume generated by the agricultural drone rotor is constant. Increasing the cross-sectional area of ​​the airflow reduces the airflow velocity. By changing the position of different differential rings 6, the vertical position, angle of attack, and sweep angle of the blades 1 are changed, so that the device rotates in the rotor airflow in a suitable direction and speed, thereby weakening the airflow intensity of the agricultural drone rotor and avoiding excessive lift loss of the agricultural drone rotor. In addition, the segmented blades 1 can achieve different angles of attack adjustment. The airflow velocity is high near the center of the rotating mechanism, and the angle of attack at this position can be increased separately to improve the airflow diffusion effect.

[0088] The above are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for controlling the airflow intensity of a plant protection drone rotor, characterized in that, The control method adjusts the airflow below the rotor of the agricultural drone through an actuator module located below the rotor. The airflow below the rotor causes the blades of the actuator module to rotate passively. The control method includes the following steps: (S1) Set the target wind speed of the rotor airflow of the agricultural drone according to the wind speed that the crop can withstand without being damaged. (S2) Acquire the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the altitude change acceleration of the agricultural drone, and the tilt angle of the agricultural drone detected by the sensor; (S3) The corrected wind speed is calculated based on the relationship between the target wind speed and the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the acceleration of the altitude change of the agricultural drone, and the tilt angle of the agricultural drone. (S4) Obtain the sensor wind speed, which is the real-time wind speed of the airflow from the rotor of the agricultural drone detected by the sensor; compare the sensor wind speed with the corrected wind speed. (S5) The execution module performs the following operations based on the comparison results: When the current wind speed of the airflow under the rotor of the agricultural drone is greater than the corrected wind speed, the blade angle of attack of the execution module is adjusted to increase the blade angle of attack, increase the rotation speed of the blades, and the airflow spreads in all directions, reducing the wind speed below the rotor of the agricultural drone. When the current wind speed of the rotor airflow of the agricultural drone is less than the corrected wind speed, the blade angle of attack of the execution module is adjusted to reduce the blade angle of attack, slow down the rotation speed of the blades, reduce the degree of airflow diffusion in all directions, and reduce the power loss of the agricultural drone. When the current wind speed of the rotor airflow of the agricultural drone is equal to the corrected wind speed, the execution module does not make any adjustments; In step (S3), the relationship between the target wind speed and the operating altitude of the agricultural drone, the horizontal flight speed of the agricultural drone, the acceleration due to altitude change of the agricultural drone, and the tilt angle of the agricultural drone is as follows: The higher the operating altitude of the agricultural drone, the higher the corrected wind speed will be compared to the target wind speed; the higher the horizontal flight speed of the agricultural drone, the higher the corrected wind speed will be compared to the target wind speed; when the altitude of the agricultural drone decreases, the greater the acceleration of the downward change in altitude of the agricultural drone, the lower the corrected wind speed will be compared to the target wind speed; the greater the tilt angle of the agricultural drone, the lower the corrected wind speed will be compared to the target wind speed. In step (S3), the formula for calculating the corrected wind speed is: ； Where Vx is the corrected wind speed, Vc is the target wind speed, a is the weight of the plant protection drone's operating altitude, b is the weight of the plant protection drone's altitude change acceleration, c is the weight of the plant protection drone's tilt angle, d is the weight of the plant protection drone's horizontal flight speed, f(x) is the fitting function of the relationship between the plant protection drone's operating altitude and wind speed, f(y) is the fitting function of the relationship between the plant protection drone's altitude-direction acceleration and wind speed, f(z) is the fitting function of the relationship between the plant protection drone's tilt angle and wind speed, and f(v) is the fitting function of the relationship between the plant protection drone's horizontal flight speed and wind speed.

2. A device for controlling the airflow intensity of a plant protection drone rotor, characterized in that, The control device is used to implement the method for controlling the airflow intensity of the rotor of a plant protection drone as described in claim 1. The control device includes a controller, a sensor, and an execution module. The controller is connected to the sensor and the execution module respectively. The execution module is installed below the rotor motor of the plant protection drone. The rotor motor is used to drive the rotor of the plant protection drone to rotate. The execution module adds tangential velocity to the airflow in a rotating manner, so that the airflow spreads in all directions to increase the coverage area of ​​the airflow of the rotor of the plant protection drone, thereby reducing the airflow speed.

3. The control device for the airflow intensity of the rotor of a plant protection drone according to claim 2, characterized in that, The sensors include an attitude sensor based on the agricultural drone's own flight controller, a rotor motor speed sensor, and a wind speed sensor; the attitude sensor is used to acquire the agricultural drone's operating altitude, horizontal flight speed, altitude change acceleration, and tilt angle; the rotor motor speed sensor is used to detect changes in the rotor speed of the agricultural drone; and the wind speed sensor is used to detect the wind speed of the airflow from the rotor of the agricultural drone.

4. The control device for the airflow intensity of the rotor of a plant protection drone according to claim 2, characterized in that, The execution module includes a rotating mechanism located at the bottom of the rotor motor, a differential displacement mechanism located on the rotating mechanism, blades located on the differential displacement mechanism, and a drive mechanism for driving the differential displacement mechanism to move in order to change the angle and position of the blades.

5. The control device for the rotor airflow intensity of a plant protection drone according to claim 4, characterized in that, The rotating mechanism includes a rotating base and a rotating slide rail disposed on the rotating base; the rotating base is connected to the rotor motor via a mounting seat, the mounting seat is fixed to the bottom of the rotor motor, and the rotating base is rotatably connected to the mounting seat.

6. The control device for the rotor airflow intensity of a plant protection drone according to claim 5, characterized in that, The differential positioning mechanism includes multiple differential rings, all of which are sleeved on the rotating slide rail. The differential rings are slidably connected to the rotating slide rail along its axial direction. The multiple differential rings include an upper sweep angle differential ring, a lower sweep angle differential ring, and at least one angle-of-attack differential ring. A connecting rod assembly is provided between the upper sweep angle differential ring and the lower sweep angle differential ring. The connecting rod assembly includes an upper connecting rod and a lower connecting rod. One end of the upper connecting rod is hinged to the upper sweep angle differential ring, one end of the lower connecting rod is hinged to the lower sweep angle differential ring, and the other end of the upper connecting rod is hinged to the other end of the lower connecting rod. The blade is mounted on the upper connecting rod. The angle-of-attack differential ring and the blade are connected by a draw wire.

7. The control device for the airflow intensity of the rotor of a plant protection drone according to claim 6, characterized in that, The drive mechanism includes multiple sets of drive components, each set of drive components being configured one-to-one with each differential ring. Each set of drive components includes a drive motor disposed inside the rotating base, a drive pulley disposed on the main shaft of the drive motor, a driven pulley disposed at the lower end of the rotating slide rail, and a transmission belt connecting the drive pulley and the driven pulley. The transmission belt is connected to the differential ring.

8. The control device for the rotor airflow intensity of a plant protection drone according to claim 5, characterized in that, The execution module also includes a speed limiting mechanism, which includes multiple centrifugal friction plates disposed inside the rotating base.

9. The control device for the airflow intensity of the rotor of a plant protection drone according to claim 6, characterized in that, The upper connecting rod is provided with a protruding shaft, and the blade is rotatably connected to the protruding shaft; the interior of the protruding shaft is a hollow structure; the blade includes a winglet, a flexible skin, and a wing assembly, the winglet is rotatably mounted on the protruding shaft, and the winglet has a connecting hole, the connecting hole being connected to one of the angle-of-attack differential rings via a pull wire; the wing assembly includes a rotating spar and ribs; wherein, the rotating spar is rotatably connected to the protruding shaft, the ribs are fixedly mounted on the rotating spar, and the flexible skin covers the ribs; the rotating spar and the pull wire are connected to the wing assembly. A first transmission mechanism is provided between the lines. The first transmission mechanism includes a rotating shaft plunger, a cylindrical protrusion, a straight groove, an inclined groove, and a return spring. The rotating shaft plunger is disposed inside the protruding shaft and is connected to another angle-of-attack differential ring via a pull wire. The cylindrical protrusion is disposed on the rotating shaft plunger, the straight groove is disposed on the protruding shaft, and the inclined groove is disposed on the rotating wing beam. The cylindrical protrusion is engaged with the straight groove and the inclined groove. The return spring is disposed inside the protruding shaft and is used to reset the rotating shaft plunger.

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