Plant protection unmanned aerial vehicle vector regulation precision targeting spraying device and method

Abstract

The application discloses a kind of plant protection unmanned plane vector regulation precision target spraying device and method, wherein the plant protection unmanned plane vector regulation precision target spraying device includes wind type centrifugal spraying device installed on plant protection unmanned plane, angle adjusting mechanism for adjusting the attitude of wind type centrifugal spraying device and control system;The wind type centrifugal spraying device is installed on the angle adjusting mechanism by quick release mechanism;The angle adjusting mechanism is used to adjust the horizontal rotation angle and the up-down deflection angle of the wind type centrifugal spraying device.The plant protection unmanned plane vector regulation precision target spraying device of the application can adjust the vector according to the parameters of fruit tree canopy, and spray with controllable wind field auxiliary centrifugal atomization nozzle, improve the penetration, reduce ground loss and reduce the risk of small droplet drift, increase the target deposition of fruit tree, and ensure the precise and controllable plant protection unmanned plane pesticide application.

Description

Technical Field

[0001] This invention belongs to the field of agricultural aviation plant protection, specifically relating to a vector-adjustable precision target spraying device and method for plant protection drones. Background Technology

[0002] Currently, fruit tree plant protection technology mainly relies on ground-based plant protection machinery and plant protection drones for precision spraying. With the policy of "reducing pesticide use and increasing efficiency" for green development, precision spraying technology has become a major research and development direction for orchard plant protection. Compared with ground-based plant protection machinery, plant protection drones have advantages such as high efficiency and good terrain adaptability. In recent years, with the vigorous promotion and development of precision agricultural aerial spraying technology and the low-altitude economy, plant protection drones have become an important force driving the rapid development of precision and unmanned agriculture. Aerial spraying by plant protection drones employs a low-volume, fine droplet application method with adjustable operating altitude. However, in actual spraying operations, due to operating conditions and environmental factors, there are problems such as "unstable deposition and penetration effects" and "easy drift of fine droplets," and the drift of droplets can cause harm to surrounding personnel, sensitive crops, or the ecological environment.

[0003] Currently, agricultural drones primarily use centrifugal atomizing nozzles for spraying pesticides. The droplet size is adjusted by controlling the rotation speed of the centrifugal nozzles to achieve different control effects. Centrifugal nozzles use centrifugal force to eject droplets, which are mainly affected by horizontal inertia and gravity, resulting in a disc-shaped atomization surface. However, excessively small droplet size and kinetic energy loss make the droplets susceptible to drift due to ambient wind speed. Although the downward wind field created by the agricultural drone increases vertical wind force, in orchards, the wind can create swirling around the ground, further exacerbating ground runoff and droplet drift. Furthermore, in orchards with large and dense canopies, pesticide penetration may be insufficient, thus affecting the application effect. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a vector-adjustable precision spraying device for agricultural drones. This device can adjust the vector according to the canopy parameters of fruit trees and, combined with a controllable wind field-assisted centrifugal atomizing nozzle, improves insufficient penetration, reduces ground runoff, lowers the risk of fine droplet drift, increases target deposition on fruit trees, and ensures precise and controllable pesticide application by agricultural drones.

[0005] The second objective of this invention is to provide a method for precise target spraying using vector adjustment of agricultural drones.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is:

[0007] A plant protection drone vector adjustment precision target spraying device includes a wind-driven centrifugal spraying device installed on the plant protection drone, an angle adjustment mechanism for adjusting the attitude of the wind-driven centrifugal spraying device, and a control system. The wind-driven centrifugal spraying device is installed on the angle adjustment mechanism via a quick-release mechanism. The angle adjustment mechanism is used to adjust the horizontal rotation angle and the vertical deflection angle of the wind-driven centrifugal spraying device.

[0008] Preferably, the angle adjustment mechanism includes a horizontal angle adjustment mechanism for adjusting the horizontal rotation angle of the air-driven centrifugal spraying device and a vertical angle adjustment mechanism for adjusting the vertical deflection angle of the air-driven centrifugal spraying device, wherein...

[0009] The vertical angle adjustment mechanism includes a first hinge seat, a second hinge seat, and a swing drive mechanism for driving the second hinge seat to swing up and down. The swing drive mechanism includes a rotating shaft, a first drive motor for driving the rotating shaft to rotate, and a worm gear transmission mechanism. The rotating shaft is a non-circular shaft, one end of which is rotatably connected to the first hinge seat via a first bearing. The second hinge seat is mounted on the rotating shaft, and a flange coupling is provided between the second hinge seat and the rotating shaft. The flange coupling is sleeved on the non-circular shaft and has a non-circular hole that mates with the non-circular shaft. The second hinge seat is fixed to the flange coupling. The first drive motor is mounted on the first hinge seat, and the main shaft of the first drive motor is connected to the worm in the worm gear transmission mechanism. The worm gear in the worm gear transmission mechanism is mounted on the rotating shaft. The rotating part of the worm gear is rotatably connected to the first hinge seat via a second bearing. A fixed seat is mounted on the second hinge seat.

[0010] The horizontal angle adjustment mechanism includes a connecting seat, a rotating seat, and a horizontal rotation mechanism mounted on the rotating seat for driving the first hinge seat to rotate. The connecting seat is fixed to the agricultural drone. The horizontal rotation mechanism includes a rotating fixed shaft, a second drive motor, and a gear transmission mechanism. The upper end of the rotating fixed shaft is rotatably connected to the connecting seat, and the lower end is fixed to the rotating seat. The lower end of the rotating seat is fixedly connected to the first hinge seat. The second drive motor is mounted on the rotating seat, and the main shaft of the second drive motor is connected to the connecting seat through the gear transmission mechanism. The gear transmission mechanism includes a driving gear mounted on the main shaft of the second drive motor and a driven gear mounted on the connecting seat. The driven gear is fixed to the rotating fixed shaft.

[0011] Preferably, the swing drive mechanism comprises two sets, symmetrically arranged on the left and right sides of the first hinge seat; correspondingly, the second hinge seat is provided with two sets of second connecting ears, each with a second hinge hole; the first hinge seat is provided with a first connecting ear on both sides of each set of second connecting ears, each with a first hinge hole; the rotating shafts in the two sets of swing drive mechanisms pass through the first hinge hole of the corresponding first connecting ear and the second hinge hole of the corresponding second connecting ear; wherein, the first bearing is disposed in the first hinge hole of the inner first connecting ear on the first hinge seat; the second bearing is disposed in the first hinge hole of the outer first connecting ear on the first hinge seat.

[0012] Preferably, the quick-release mechanism includes a first adapter and a second adapter, wherein the upper end of the first adapter is connected to the fixed base by screws; the lower end of the second adapter is also connected to the air-driven centrifugal spraying device by screws; the first adapter and the second adapter are connected by a quick-release structure; the quick-release structure is one or more of a snap-fit ​​connection structure, a threaded connection structure, and a screw connection structure.

[0013] Preferably, the air-driven centrifugal spraying device includes an air inlet module, an air outlet module, and an atomizing module. The air inlet module includes a fixed outer cover, an upper fixed plate and a lower fixed plate disposed on the upper side of the fixed outer cover, and a brushless ducted air source disposed between the upper and lower fixed plates. An air inlet shroud is disposed on the upper fixed plate, and the air inlet shroud is mounted on the upper fixed plate by multiple sets of fixed aluminum pillars. The upper end of each set of fixed aluminum pillars is fixed to the second adapter seat, and the lower end passes through the mounting hole of the air inlet shroud and is fixed to the upper fixed plate. The upper and lower fixed plates are respectively fixed to the upper and lower sides of the fixed outer cover. The air outlet module includes a rectifier air duct, the upper end of which is fixed to the lower fixed plate. The atomizing module includes a centrifugal atomizing nozzle and a fixing component for mounting the centrifugal atomizing nozzle on the lower fixed plate.

[0014] Preferably, the outer diameter of the rectifier duct gradually decreases first and then gradually increases. The inner cavity of the rectifier duct is composed of a converging inlet, an intermediate throat, and a terminal diffuser outlet, and the terminal diffuser outlet has a conical structure. The inner wall of the rectifier duct is provided with multiple sets of guide vanes, which are arranged in a circular shape at equal angles. Each set of guide vanes extends axially along the outer contour of the rectifier duct.

[0015] Preferably, the control system includes a system control board, a power supply component, an electronic speed controller, and a magnetic encoder. The system control board controls the two-degree-of-freedom rotation and attitude adjustment of the angle adjustment mechanism, and simultaneously controls the rotational speed of the brushless ducted air source and the centrifugal atomizing nozzle of the air-driven centrifugal spraying device. The power supply component supplies power to all electrical components and includes a power adapter step-down module and a power protection module. The electronic speed controller provides hardware drive for the rotational speed of the brushless ducted air source and the centrifugal atomizing nozzle, and distributes power according to the current consumption of each electrical component. The magnetic encoder detects the horizontal rotation angle and vertical deflection angle of the angle adjustment mechanism, as well as the rotational speed of the brushless ducted air source and the centrifugal atomizing nozzle in the air-driven centrifugal spraying device. The magnetic encoder is fixed on a non-rotating component, and a radial magnet is fixedly provided on the radial end face of the rotating component. The magnetic encoder and the radial magnet are arranged coaxially, and the installation distance between the encoder chip of the magnetic encoder and the radial magnet is set to 3mm.

[0016] A method for precise target spraying using vector adjustment of agricultural drones includes the following steps:

[0017] S1. The LiDAR and RGB camera mounted on the plant protection drone work together to scan and photograph the fruit trees, and obtain the three-dimensional point cloud information of the fruit tree canopy, RGB image data and the geographical coordinates of the corresponding fruit trees.

[0018] S2. Preprocess the acquired 3D point cloud information and RGB image data to extract key feature parameters of the fruit tree canopy, including the height, width, volume, leaf area density, and canopy tilt angle of the fruit tree canopy.

[0019] S3. Conduct multiple pre-application tests, setting different operating conditions such as flight altitude, flight speed, outlet wind speed of the wind-driven centrifugal sprayer, and droplet size. Obtain the droplet deposition amount and ground liquid loss rate under each operating condition to form an experimental sample dataset. Input the experimental sample dataset and the extracted key feature parameters into the neural network model for training until the model converges or reaches the preset training index to obtain a trained fruit tree targeted pesticide application prediction model. Use this prediction model to determine the optimal pesticide application parameters.

[0020] S4. Based on the determined optimal application parameters, the horizontal rotation angle, vertical deflection angle, outlet wind speed, and centrifugal atomizing nozzle speed of the plant protection drone's wind-driven centrifugal spraying device are adjusted in real time. Simultaneously, according to the actual location and volume of the fruit tree canopy and the drone's flight path, a circumferential target spraying mode is adopted, matched with a fixed-angle spraying mode or an up-and-down swing spraying mode. When the volume of the fruit tree canopy is less than the preset threshold, circumferential target spraying combined with fixed-angle spraying is used; when the volume of the fruit tree canopy is greater than the preset threshold, circumferential target spraying combined with up-and-down swing spraying is used to achieve precise target spraying and full coverage of the fruit tree canopy.

[0021] Preferably, in step S2, the three-dimensional point cloud information is first preprocessed by denoising, downsampling, ground and trunk segmentation, and operation area division; multiple sets of RGB images are stitched, corrected, and cropped to obtain remote sensing orthophotos; then, the three-dimensional point cloud data is identified and detected by clustering algorithm, and the remote sensing orthophotos are target detected and segmented by neural network segmentation model to complete the extraction of key feature parameters of fruit tree canopy and coordinate transformation.

[0022] Preferably, in step S4, when the plant protection drone is operating forward, the outlet wind speed of the wind-driven centrifugal spraying device and the rotation speed of the centrifugal atomizing nozzle increase and decrease synchronously with the density of the fruit tree canopy, and the droplet size decreases and increases accordingly. When the plant protection drone flies along the rows of fruit trees, the wind-driven centrifugal spraying device is deployed outward and the spray angle is perpendicular to the canopy slope. When the plant protection drone flies at the top of the canopy, the wind-driven centrifugal spraying device is deployed inward and the spray angle is perpendicular to the canopy slope. When the fruit tree canopy volume is small, a fixed angle spraying mode is used, maintaining a horizontal circling target, and the vertical spraying device axis is perpendicular to the canopy slope. When the canopy volume is large, an up-and-down swing spraying mode is used, maintaining a horizontal circling target, and the vertical spraying device swings smoothly along the canopy partition line.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] 1. The plant protection drone vector adjustment precision target spraying device of the present invention can adjust the attitude of the wind-driven centrifugal spraying device through the angle adjustment mechanism, so that the mist sprayed by the wind-driven centrifugal spraying device can be directed in different directions to achieve precise target deposition on the fruit tree canopy, thereby effectively improving the droplet penetration ability and target adhesion deposition rate, reducing the risk of random droplet drift, and thus reliably realizing precise target spraying operation on fruit trees.

[0025] 2. The wind-driven centrifugal spraying device in the vector adjustment precision target spraying device of the plant protection drone of the present invention can be quickly disassembled and replaced with the help of a quick-release mechanism, making disassembly and assembly more convenient and adaptable, thereby meeting the spraying needs of different operation scenarios and different fruit tree species.

[0026] 3. The vector-adjustable precision target spraying device for plant protection drones of the present invention can achieve adaptive target spraying for tree canopies of different shapes. On the one hand, it ensures target accuracy by adjusting the horizontal rotation angle and vertical deflection angle of the wind-driven centrifugal spraying device; on the other hand, it can improve the canopy penetration effect and target deposition effect of droplets and suppress droplet drift by adjusting the outlet wind speed of the wind-driven centrifugal spraying device and the rotation speed of the centrifugal atomizing nozzle. At the same time, it can match the different flight paths of the plant protection drone and switch the corresponding target spraying operation mode, thereby ensuring the uniformity of pesticide deposition effect in the fruit tree canopy.

[0027] 4. The plant protection drone vector adjustment precision target spraying device of the present invention acquires three-dimensional point cloud data and RGB image information of the fruit tree canopy through lidar and RGB camera, and extracts key feature parameters such as the height, width, volume, leaf area density and canopy tilt angle of the fruit tree canopy through processing and identification. The optimal operation parameters are obtained by constructing a fruit tree target spraying prediction model. The control system dynamically adjusts the droplet size, effective spraying distance and spraying width of the air-driven centrifugal spraying device according to the optimal operation parameters, further enhancing the droplet penetration and the adhesion and deposition effect on the leaves. It can realize different directional target spraying operation modes according to two flight operation routes: flying between fruit tree rows and flying over the top of the canopy, which greatly improves the accuracy of target spraying and reduces pesticide droplet drift and waste of pesticide solution on the ground. Attached Figure Description

[0028] Figure 1 This is a three-dimensional structural diagram of the plant protection drone vector adjustment precision target spraying device of the present invention.

[0029] Figure 2 This is a three-dimensional structural diagram of the angle adjustment mechanism.

[0030] Figure 3 This is an exploded view of the components of the angle adjustment mechanism.

[0031] Figure 4 This is a three-dimensional structural diagram of the quick-release mechanism.

[0032] Figure 5 This is a three-dimensional structural diagram of a wind-driven centrifugal spraying device.

[0033] Figure 6 An exploded view of the components of a pneumatic centrifugal spraying device.

[0034] Figure 7 This is a three-dimensional structural diagram of the guide vanes in the rectifier duct.

[0035] Figure 8 This is a flowchart illustrating the vector adjustment and precise target spraying method for agricultural drones according to the present invention. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0037] See Figures 1-8 The present invention relates to a vector-adjustable precision target spraying device for agricultural drones, which is located at the bottom of the rotor motor of the agricultural drone. It includes a wind-driven centrifugal spraying device 3 mounted on the agricultural drone, an angle adjustment mechanism 1 for adjusting the attitude of the wind-driven centrifugal spraying device 3, and a control system. The wind-driven centrifugal spraying device 3 is mounted on the angle adjustment mechanism 1 via a quick-release mechanism 2. The angle adjustment mechanism 1 is used to adjust the horizontal rotation angle and vertical deflection angle of the wind-driven centrifugal spraying device 3. This angle adjustment mechanism 1 includes a horizontal angle adjustment mechanism for adjusting the horizontal rotation angle of the wind-driven centrifugal spraying device 3 and a vertical angle adjustment mechanism for adjusting the vertical deflection angle of the wind-driven centrifugal spraying device 3. The end of the wind-driven centrifugal spraying device 3 can generate a high-speed directional airflow and droplets with different atomization degrees, blowing the droplets towards the fruit tree canopy. The wind speed and droplet size are adjusted according to the canopy structure of different fruit trees. The control system is used to collect, process, and control real-time data such as the target spraying angle, wind intensity, and droplet size.

[0038] See Figures 1-8The up-and-down angle adjustment mechanism includes a first hinge seat 12, a second hinge seat 18, and a swing drive mechanism for driving the second hinge seat 18 to swing up and down. The swing drive mechanism includes a rotating shaft 13, a first drive motor 10 for driving the rotating shaft 13 to rotate, and a worm gear transmission mechanism. The rotating shaft 13 is a non-circular shaft, and one end of the rotating shaft 13 is rotatably connected to the first hinge seat 12 via a first bearing 14. The second hinge seat 18 is mounted on the rotating shaft 13, and a flange coupling 15 is provided between the second hinge seat 18 and the rotating shaft 13. The flange coupling 15 is sleeved on the non-circular shaft and fixed to the rotating shaft 13 by nut screws. The flange coupling 15 has a non-circular hole that mates with the non-circular shaft. The second hinge seat 18 is fixed to the flange coupling 15. The first drive motor 10 is mounted on the first hinge seat 12. The main shaft of the first drive motor 10 is connected to the worm 11 in the worm gear transmission mechanism, and the worm gear 16 in the worm gear transmission mechanism is mounted on the rotating shaft 13; the rotating part of the worm gear 16 is rotatably connected to the first hinge seat 12 through the second bearing 17; a fixed seat 19 is mounted on the second hinge seat 18; in this embodiment, the second hinge seat 18 is provided with two sets of second connecting ears, and the second connecting ears are provided with second hinge holes; the first hinge seat 12 is provided with first connecting ears on both sides of each set of second connecting ears, and the first connecting ears are provided with first hinge holes; the rotating shaft 13 passes through the first hinge hole and the second hinge hole; the first bearing 14 is disposed in the first hinge hole of the first connecting ear located on the inner side of the first hinge seat 12; the second bearing 17 is disposed in the first hinge hole of the first connecting ear located on the outer side of the first hinge seat 12. With the above settings, when it is necessary to adjust the vertical deflection angle of the air-driven centrifugal spraying device 3, the first drive motor 10 drives the worm gear 11 to rotate, thereby driving the worm wheel 16 mounted on the rotating shaft 13 to rotate, thus driving the rotating shaft 13 to rotate; while the rotating shaft 13 rotates, it will drive the flange coupling 15 and the second hinge seat 18 mounted on the flange coupling 15 to deflect vertically, thereby adjusting the vertical deflection angle of the air-driven centrifugal spraying device 3.

[0039] In this embodiment, the angle between the horizontal rotation center axis and the vertical swing center axis is 0° to 90°, which can adapt to the target spraying angle requirements of different canopy morphologies.

[0040] See Figures 1-8The horizontal angle adjustment mechanism includes a connecting seat 4, a rotating seat 8, and a horizontal rotation mechanism mounted on the rotating seat 8 for driving the first hinge seat 12 to rotate. The connecting seat 4 is fixed to the agricultural drone. The horizontal rotation mechanism includes a rotating fixed shaft 7, a second drive motor, and a gear transmission mechanism. The upper end of the rotating fixed shaft 7 is rotatably connected (i.e., via a third bearing 5) to the connecting seat 4, and the lower end is fixed to the rotating seat 8. The lower end of the rotating seat 8 is fixedly connected to the first hinge seat 12. The second drive motor is mounted on the rotating seat 8, and the main shaft of the second drive motor is connected to the connecting seat 4 via the gear transmission mechanism. The wheel transmission mechanism includes a drive gear 9 mounted on the main shaft of the second drive motor and a driven gear 6 mounted on the connecting seat 4. The driven gear 6 is fixed on the rotating fixed shaft 7. When it is necessary to adjust the horizontal rotation angle of the air-driven centrifugal spraying device 3, the second drive motor drives the drive gear 9 to rotate. Since the driven gear 6 is fixed on the connecting seat 4, the rotating fixed shaft 7, the rotating seat 8, and the second drive motor will rotate around the driven gear 6, thereby driving the first hinge seat 12, the second hinge seat 18, and the air-driven centrifugal spraying device 3 to rotate, thereby adjusting the horizontal rotation angle of the air-driven centrifugal spraying device 3.

[0041] See Figures 1-8 The swing drive mechanism consists of two sets, symmetrically arranged on the left and right sides of the first hinge seat 12. Correspondingly, the rotating shaft 13 also consists of two sets, coaxially arranged opposite each other to ensure that the rotation center axis is completely coincident. Each set of rotating shaft 13 is an irregularly shaped shaft, with its inner end fixedly connected to the second connecting ear on the corresponding side of the second hinge seat 18 via a flange coupling 15, and its outer end connected to the worm gear transmission mechanism of the swing drive mechanism on the corresponding side. The first drive motor 10 in the two sets of swing drive mechanisms ensures that the speed and rotation angle are completely consistent through synchronous control, synchronously driving the two sets of rotating shaft 13 to rotate coaxially, thereby driving the two sets of second connecting ears of the second hinge seat 18 to deflect synchronously, and finally driving the second hinge seat 18 and the wind-driven centrifugal spraying device 3 installed below it to complete a smooth and unbiased up-and-down swing.

[0042] See Figures 1-8 The quick-release mechanism 2 includes a first adapter 20 and a second adapter 21. The upper end of the first adapter 20 is connected to the fixed base 19 by screws. The lower end of the second adapter 21 is also connected to the air-driven centrifugal spraying device 3 by screws. The first adapter 20 and the second adapter 21 are connected by a quick-release structure. The quick-release structure is one or more of the following: a snap-fit ​​connection structure, a threaded connection structure, and a screw connection structure.

[0043] In this embodiment, the second adapter 21 is provided with a rotating fixing buckle, and the first adapter 20 is provided with fixing holes. The inner wall of the first adapter 20 has three vertical sliding grooves of different sizes, and the outer wall of the second adapter 21 has three protrusions of different sizes that match the corresponding vertical sliding grooves. The three protrusions of the second adapter 21 are vertically pushed into the corresponding three vertical sliding grooves of the first adapter 20, rotate counterclockwise through the rotating sliding grooves, and then vertically sink into the limiting slots. The edge of the limiting slot... There is a protrusion used to limit the horizontal rotation of the second adapter seat 21; the rotating slide has a movable gap to ensure that the second adapter seat 21 slides smoothly. However, the movable gap may cause the agricultural drone to vibrate up and down and rotate loose during flight or during the vertical rotation of the angle adjustment mechanism 1. Therefore, by fixing the sides of the first adapter seat 20 and the second adapter seat 21 with screws, the vibration and rotation of the first adapter seat 20 and the second adapter seat 21 in the axial direction are limited, thereby ensuring operational safety.

[0044] In this embodiment, the fixing buckles on the edge of the second adapter 21 have different shapes and sizes to achieve installation positioning; the first adapter 20 and the second adapter 21 have only one fixing screw hole, and the fixing screw passes through the fixing screw hole on the first adapter 20 and the second adapter 21 to achieve limiting, thereby preventing rotation and loosening caused by vibration of the body of the agricultural drone and the cantilever beam of the device, and ensuring operational safety.

[0045] See Figures 1-8 The air-driven centrifugal spraying device 3 includes an air inlet module, an air outlet module, and an atomization module, wherein...

[0046] The air intake module includes a fixed outer cover 26, an upper fixed plate 24 and a lower fixed plate 27 disposed on the upper side of the fixed outer cover 26, and a brushless ducted air source 25 disposed between the upper fixed plate 24 and the lower fixed plate 27. An air intake shroud 23 is disposed on the upper fixed plate 24, and the air intake shroud 23 is mounted on the upper fixed plate 24 by multiple sets of fixing aluminum pillars 22. The upper end of each set of fixing aluminum pillars 22 is fixed to the second adapter 21, and the lower end passes through the mounting holes of the air intake shroud 23 and is fixed to the upper fixed plate 24. The upper fixed plate 24 and the lower fixed plate 27 are respectively fixed to the upper and lower sides of the fixed outer cover 26.

[0047] The air outlet module includes a rectifier duct 28, the upper end of which is fixed to the lower fixed plate 27. The outer diameter of the rectifier duct 28 gradually decreases and then gradually increases. The inner cavity of the rectifier duct 28 consists of a converging inlet, a middle throat, and a terminal diffuser outlet. The terminal diffuser outlet has a conical structure, which can accelerate the internal airflow. In addition, the inner wall of the rectifier duct 28 is provided with multiple sets of guide vanes 31, which are arranged in a circular shape at equal angles. Each set of guide vanes 31 extends axially along the outer contour of the rectifier duct 28, which allows the fine droplets generated by the high-speed rotation of the centrifugal atomizing nozzle 30 to move in a directional and accelerated manner with the high-speed airflow, thereby increasing the deposition rate of droplets on the target.

[0048] The atomization module includes a centrifugal atomizing nozzle 30 and a fastener 29 for mounting the centrifugal atomizing nozzle 30 on the lower fixed plate 27.

[0049] With the above configuration, the brushless ducted air source 25 generates airflow through high-speed rotation, and forms negative pressure through the middle constriction structure of the rectifier duct 28. Under the action of the internal and external air pressure difference, the external airflow and the downwash airflow generated by the rotor of the agricultural drone enter the inner flow channel laterally through the air intake shroud 23, cooling the motor of the brushless ducted air source 25. Subsequently, the airflow is oriented by the guide vanes in the rectifier duct 28, forming a stable axial airflow, providing auxiliary wind force for the droplets generated by centrifugal atomization, thereby improving the droplet penetration and promoting the rapid deposition of droplets onto the target. In this embodiment, the guide vanes can guide the droplets to move directionally and accelerate with the high-speed airflow, improving the deposition rate of droplets on the target; at the same time, the high-speed airflow can further break up the droplets, making the droplet size more uniform and the distribution more reasonable, further ensuring good deposition and adhesion effects.

[0050] See Figures 1-8The control system includes a system control board, a power supply assembly, an electronic speed controller, and a magnetic encoder. The system control board controls the two-degree-of-freedom rotation and attitude adjustment of the angle adjustment mechanism 1, and simultaneously controls the rotational speed of the brushless ducted air source 25 and the centrifugal atomizing nozzle 30 of the wind-driven centrifugal spraying device 3. Wind speed is controlled by adjusting the rotational speed of the brushless ducted air source 25, and droplet size is controlled by adjusting the rotational speed of the centrifugal atomizing nozzle 30. The system control board incorporates PID and filtering algorithms for error control and data smoothing. The power supply assembly supplies power to all electrical components and includes a power adapter. The device is equipped with a step-down module and a power protection module; the electronic speed controller provides speed hardware drive for the brushless ducted air source 25 and the centrifugal atomizing nozzle 30, and distributes power according to the current consumption of each electrical component; the magnetic encoder is used to detect the horizontal rotation angle and vertical deflection angle of the angle adjustment mechanism 1, as well as the speed of the brushless ducted air source 25 and the centrifugal atomizing nozzle 30 in the air-driven centrifugal spraying device 3. The magnetic encoder is fixed on the non-rotating parts, and a radial magnet is fixed on the radial end face of the rotating parts. The magnetic encoder and the radial magnet are arranged coaxially, and the installation distance between the encoder chip of the magnetic encoder and the radial magnet is set to 3mm.

[0051] To achieve real-time detection and precise angle control, radial magnets are fixedly installed on the sides of both the drive gear 9 and the rotating shaft 13. The corresponding magnetic encoders are coaxial with the axes of the drive gear 9 and the rotating shaft 13, and are installed on the connecting seat 4 and the first hinge seat 12. The radial magnets rotate with the components, while the magnetic encoder remains stationary. During operation, the magnetic encoder detects the changing magnetic field generated by the radial magnets and then calculates angle and rotational speed data using a program algorithm. This allows for real-time acquisition and calibration of the horizontal rotation angle and vertical deflection angle of the angle adjustment mechanism 1, enabling real-time control and attitude adjustment of the entire mechanism. This ensures the accuracy and stability of angle adjustment, guaranteeing precise target spraying.

[0052] In this invention, the control principles for angle adjustment, wind speed, and the rotation speed of the centrifugal atomizing nozzle 30 are as follows: By controlling the rotation speed and direction of the decelerated brushless motor (i.e., the first drive motor 10 and the second drive motor), the horizontal rotation angle and vertical deflection angle are adjusted. The rotation speed of the brushless ducted air source 25 and the centrifugal atomizing nozzle 30 are controlled by the duty cycle of the PWM, thereby adjusting the rotation speed of the brushless ducted air source 25 and thus controlling the wind speed. By adjusting the rotation speed of the centrifugal atomizing nozzle 30, the droplet size is controlled. The real-time rotation speed and real-time attitude angle are obtained by a magnetic encoder, and its embedded PID algorithm and filtering algorithm can perform error control and smoothing processing on the data.

[0053] Compared with existing technologies, the vector-adjustable precision target spraying device for agricultural drones of the present invention has the following advantages:

[0054] 1. The angle adjustment mechanism 1 in this invention uses a reduction brushless motor (first drive motor 10 and second drive motor) as the drive source. Through the gear transmission mechanism, the angle adjustment mechanism 1 and the air-driven centrifugal spraying device 3 are driven to rotate horizontally as a whole, thereby adjusting the horizontal rotation angle of the air-driven centrifugal spraying device 3. Through the worm gear 16 and worm 11 mechanism, the air-driven centrifugal spraying device 3 is driven to swing up and down, thereby adjusting the vertical deflection angle of the air-driven centrifugal spraying device 3. The horizontal rotation motion and the vertical deflection motion work together to enable the mist sprayed by the air-driven centrifugal spraying device 3 to be directed in different directions to achieve precise target deposition, improve the droplet penetration and target deposition rate, reduce the risk of droplet drift, and reliably achieve precise target spraying operations. In addition, gear transmission features high output torque and high transmission accuracy, which can ensure smooth operation of the mechanism at low speeds; the reduction brushless motor integrates a reduction gear set, which combines the advantages of high efficiency and fast response of brushless motor with the high precision and high stability of reduction mechanism, effectively improving the accuracy of angle adjustment and smooth operation, further optimizing the droplet deposition effect, and ensuring precise target spraying performance.

[0055] 2. The wind-driven centrifugal spraying device 3 of the present invention generates directional airflow through the brushless duct air source 25. The airflow is further accelerated and regulated into an axially stable flow field by the rectifier air duct 28, which can effectively enhance the penetration effect of the droplets on the canopy. The spraying width can be adjusted by changing the airflow intensity by adjusting the duct wind speed. At the same time, the droplet size can be precisely controlled by adjusting the rotation speed of the centrifugal atomizing nozzle 30, thereby improving the adhesion and deposition effect of the droplets on the fruit tree target canopy.

[0056] 3. The wind-driven centrifugal spraying device 3 in this invention can be quickly disassembled and replaced through a quick-release mechanism. It can also be compatible with different types of centrifugal atomizing nozzles 30 by replacing the adapter fixing parts 29. It has strong adaptability and can meet the application needs of different operation scenarios and different fruit tree species.

[0057] See Figure 8 The present invention provides a method for precise target spraying using a plant protection drone with vector adjustment, comprising fruit tree canopy perception and feature parameter acquisition, prediction model construction, and spraying operation parameter control. The spraying operation control parameters include controlling the angle of the wind-driven centrifugal spraying device 3, the rotation speed of the brushless duct air source 25, and the rotation speed of the centrifugal atomizing nozzle 30. Based on the fruit tree canopy structure parameters, the wind field intensity, target spraying angle, and droplet size of the wind-driven centrifugal spraying device 3 are controlled to further improve the droplet deposition effect in the fruit tree canopy. Specifically, the method includes the following steps:

[0058] S1. The LiDAR and RGB camera mounted on the plant protection drone work together to scan and photograph the fruit trees, and obtain the three-dimensional point cloud information of the fruit tree canopy, RGB image data and the geographical coordinates of the corresponding fruit trees.

[0059] S2. Preprocess the acquired 3D point cloud information and RGB image data to extract key feature parameters of the fruit tree canopy. These key feature parameters include the height, width, volume, leaf area density, and canopy tilt angle of the fruit tree canopy. Specifically:

[0060] First, the collected raw 3D point cloud information and RGB image data are preprocessed: the collected raw 3D point cloud information is subjected to noise reduction, downsampling, ground and trunk segmentation, and operation area division, etc., to remove redundant interference data, reduce the amount of data and clarify the effective operation range; at the same time, multiple sets of RGB images are stitched, corrected and cropped to obtain clear remote sensing orthophotos, which provide an accurate data foundation for the subsequent identification and extraction of key feature parameters of fruit tree canopy, and ensure the accuracy of subsequent identification and processing.

[0061] Secondly, key feature parameters of the fruit tree canopy are identified and extracted from the 3D point cloud data and the stitched remote sensing orthophoto. Specifically, the 3D point cloud data is identified and detected using a clustering algorithm, facilitating further volume calculation and contour extraction of the canopy point cloud to obtain the height and width of the fruit tree canopy under the 3D point cloud. Furthermore, 2D point cloud data slices are obtained through projection onto different planes, allowing for convenient calculation of the canopy inclination angle. For the remote sensing orthophoto, a neural network segmentation model is used to detect and segment the canopies of different fruit trees, obtaining the width and center of the canopy under the RGB image. Simultaneously, the identified fruit tree canopies are transformed from pixel coordinates to actual geographic location coordinates. Combined with pre-marked coordinate information, the actual position coordinates of each fruit tree canopy are finally obtained, further reducing positioning errors and improving the accuracy of fruit tree canopy feature parameter identification.

[0062] In addition, to ensure data accuracy, the extracted height and width of the fruit tree canopy were compared and corrected with the results of data recognition processing and manual calculation. This further improved the accuracy of key characteristic parameters of the fruit tree canopy and provided a reliable basis for determining subsequent pesticide application parameters.

[0063] S3. Conduct multiple pre-application tests, setting different operating conditions such as flight altitude, flight speed, outlet wind speed of the wind-driven centrifugal sprayer 3, and droplet size. Obtain the droplet deposition amount and ground pesticide loss rate under each operating condition to form an experimental sample dataset. Input the experimental sample dataset and the extracted key feature parameters into the neural network model for training until the model converges or reaches the preset training index to obtain the fruit tree targeted pesticide application prediction model. Determine the optimal pesticide application parameters through the fruit tree targeted pesticide application prediction model.

[0064] S4. Based on the determined optimal application parameters, the control system adjusts in real time the horizontal rotation angle, vertical deflection angle, outlet wind speed of the centrifugal spraying device 3, and rotation speed of the centrifugal atomizing nozzle 30 on the plant protection drone. Simultaneously, it acquires angle and rotation speed data in real time for data processing and dynamic adjustment to ensure precise matching of application parameters with the actual application scenario. Furthermore, based on the actual location and size of the fruit tree canopy and the drone's flight path, it adopts a circumferential target spraying mode, matched with a fixed-angle spraying mode or a vertical swing spraying mode, to achieve precise target application and full coverage of the fruit tree canopy. Specifically:

[0065] When the agricultural drone is operating, the outlet wind speed of the wind-driven centrifugal spraying device 3 and the rotation speed of the centrifugal atomizing nozzle 30 change synchronously with the density of the fruit tree canopy: at the front and rear of the fruit tree canopy, the distance between the wind-driven centrifugal spraying device 3 and the fruit tree canopy is relatively far, and the outlet wind speed is adjusted to the lowest and the droplet size is set to a larger size; as the agricultural drone moves forward, the fruit tree canopy gradually becomes denser and then becomes sparser. The wind-driven centrifugal spraying device 3 rotates horizontally around the fruit tree canopy with the center of the canopy as the origin to apply pesticides, and its outlet wind speed increases and then decreases synchronously, the rotation speed of the centrifugal atomizing nozzle 30 increases and then decreases synchronously, and the droplet size decreases and then increases accordingly, ensuring accurate droplet deposition and reducing drift.

[0066] Different target spraying modes are adopted for different flight operation routes: when the plant protection drone flies along the rows of fruit trees, the wind-driven centrifugal spraying device 3 is deployed outward and the spraying angle is perpendicular to the slope of the tree canopy; when the plant protection drone flies at the top of the tree canopy, the wind-driven centrifugal spraying device 3 is deployed inward and the spraying angle is perpendicular to the slope of the tree canopy, thereby improving the target accuracy of different flight routes.

[0067] For different fruit tree canopy volumes, corresponding spraying modes are matched. The spraying modes can be divided into fixed-angle spraying and up-and-down swing spraying. When the fruit tree canopy volume is less than a preset threshold, the spray width can be adjusted by changing the outlet wind speed to achieve full canopy coverage. In this case, a combination of circling and fixed-angle spraying is used, that is, circling and targeting in the horizontal direction, and the axis of the wind-driven centrifugal spraying device 3 is perpendicular to the canopy slope in the vertical direction. When the fruit tree canopy volume is greater than the preset threshold, full coverage cannot be achieved by simply changing the wind speed and adjusting the spray width. In this case, a combination of circling and up-and-down swing spraying is used, that is, circling and targeting in the horizontal direction is still maintained, and the wind-driven centrifugal spraying device 3 swings up and down along the canopy partition line in the vertical direction. As the plant protection drone moves forward, the swing trajectory is a smooth wave curve, ensuring that all areas of the fruit tree canopy can be accurately covered, further reducing droplet drift and improving the droplet penetration and deposition effect.

[0068] 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 vector-adjustable precision target spraying device for agricultural protection drones, characterized in that, The device includes a wind-driven centrifugal spraying device installed on an agricultural drone, an angle adjustment mechanism for adjusting the attitude of the wind-driven centrifugal spraying device, and a control system. The wind-driven centrifugal spraying device is installed on the angle adjustment mechanism via a quick-release mechanism. The angle adjustment mechanism is used to adjust the horizontal rotation angle and the vertical deflection angle of the wind-driven centrifugal spraying device.

2. The vector-adjustable precision target spraying device for agricultural drones according to claim 1, characterized in that, The angle adjustment mechanism includes a horizontal angle adjustment mechanism for adjusting the horizontal rotation angle of the air-driven centrifugal spraying device and a vertical angle adjustment mechanism for adjusting the vertical deflection angle of the air-driven centrifugal spraying device. The vertical angle adjustment mechanism includes a first hinge seat, a second hinge seat, and a swing drive mechanism for driving the second hinge seat to swing up and down. The swing drive mechanism includes a rotating shaft, a first drive motor for driving the rotating shaft to rotate, and a worm gear transmission mechanism. The rotating shaft is a non-circular shaft, one end of which is rotatably connected to the first hinge seat via a first bearing. The second hinge seat is mounted on the rotating shaft, and a flange coupling is provided between the second hinge seat and the rotating shaft. The flange coupling is sleeved on the non-circular shaft and has a non-circular hole that mates with the non-circular shaft. The second hinge seat is fixed to the flange coupling. The first drive motor is mounted on the first hinge seat, and the main shaft of the first drive motor is connected to the worm in the worm gear transmission mechanism. The worm gear in the worm gear transmission mechanism is mounted on the rotating shaft. The rotating part of the worm gear is rotatably connected to the first hinge seat via a second bearing. A fixed seat is mounted on the second hinge seat. The horizontal angle adjustment mechanism includes a connecting seat, a rotating seat, and a horizontal rotation mechanism mounted on the rotating seat for driving the first hinge seat to rotate. The connecting seat is fixed to the agricultural drone. The horizontal rotation mechanism includes a rotating fixed shaft, a second drive motor, and a gear transmission mechanism. The upper end of the rotating fixed shaft is rotatably connected to the connecting seat, and the lower end is fixed to the rotating seat. The lower end of the rotating seat is fixedly connected to the first hinge seat. The second drive motor is mounted on the rotating seat, and the main shaft of the second drive motor is connected to the connecting seat through the gear transmission mechanism. The gear transmission mechanism includes a driving gear mounted on the main shaft of the second drive motor and a driven gear mounted on the connecting seat. The driven gear is fixed to the rotating fixed shaft.

3. The vector-adjustable precision target spraying device for agricultural drones according to claim 2, characterized in that, The swing drive mechanism consists of two sets, symmetrically arranged on the left and right sides of the first hinge seat. Correspondingly, the second hinge seat is provided with two sets of second connecting ears, each with a second hinge hole. The first hinge seat has a first connecting ear on each side of each set of second connecting ears, each with a first hinge hole. The rotating shafts in the two sets of swing drive mechanisms pass through the first hinge hole of the corresponding first connecting ear and the second hinge hole of the corresponding second connecting ear. The first bearing is located in the first hinge hole of the inner first connecting ear on the first hinge seat, and the second bearing is located in the first hinge hole of the outer first connecting ear on the first hinge seat.

4. The vector-adjustable precision target spraying device for agricultural drones according to claim 3, characterized in that, The quick-release mechanism includes a first adapter and a second adapter. The upper end of the first adapter is connected to the fixed base by screws. The lower end of the second adapter is also connected to the air-driven centrifugal spraying device by screws. The first adapter and the second adapter are connected by a quick-release structure. The quick-release structure is one or more of the following: a snap-fit ​​connection structure, a threaded connection structure, and a screw connection structure.

5. The vector-adjustable precision target spraying device for agricultural drones according to claim 4, characterized in that, The air-driven centrifugal spraying device includes an air inlet module, an air outlet module, and an atomizing module. The air inlet module includes a fixed outer cover, an upper fixed plate and a lower fixed plate disposed on the upper side of the fixed outer cover, and a brushless ducted air source disposed between the upper and lower fixed plates. An air inlet shroud is disposed on the upper fixed plate, and the air inlet shroud is mounted on the upper fixed plate by multiple sets of fixed aluminum pillars. The upper end of each set of fixed aluminum pillars is fixed to the second adapter seat, and the lower end passes through the mounting hole of the air inlet shroud and is fixed to the upper fixed plate. The upper and lower fixed plates are respectively fixed to the upper and lower sides of the fixed outer cover. The air outlet module includes a rectifier air duct, the upper end of which is fixed to the lower fixed plate. The atomizing module includes a centrifugal atomizing nozzle and a fixing component for mounting the centrifugal atomizing nozzle on the lower fixed plate.

6. The vector-adjustable precision target spraying device for agricultural drones according to claim 5, characterized in that, The outer diameter of the rectifier duct gradually decreases and then gradually increases. The inner cavity of the rectifier duct consists of a converging inlet, a middle throat, and a terminal diffuser outlet, which has a conical structure. The inner wall of the rectifier duct is provided with multiple sets of guide vanes, which are arranged in a circular shape at equal angles. Each set of guide vanes extends axially along the outer contour of the rectifier duct.

7. The vector-adjustable precision target spraying device for agricultural drones according to claim 6, characterized in that, The control system includes a system control board, a power supply assembly, an electronic speed controller, and a magnetic encoder. The system control board controls the two-degree-of-freedom rotation and attitude adjustment of the angle adjustment mechanism, and simultaneously controls the rotational speed of the brushless ducted air source and the centrifugal atomizing nozzle of the air-driven centrifugal spraying device. The power supply assembly supplies power to all electrical components and includes a power adapter step-down module and a power protection module. The electronic speed controller provides hardware drive for the rotational speed of the brushless ducted air source and the centrifugal atomizing nozzle, and distributes power according to the current consumption of each electrical component. The magnetic encoder detects the horizontal rotation angle and vertical deflection angle of the angle adjustment mechanism, as well as the rotational speed of the brushless ducted air source and the centrifugal atomizing nozzle in the air-driven centrifugal spraying device. The magnetic encoder is fixed to a non-rotating component, and a radial magnet is fixed to the radial end face of the rotating component. The magnetic encoder and the radial magnet are arranged coaxially.

8. A method for precise target spraying using vector adjustment of an agricultural drone, characterized in that, Includes the following steps: S1. The LiDAR and RGB camera mounted on the plant protection drone work together to scan and photograph the fruit trees, and obtain the three-dimensional point cloud information of the fruit tree canopy, RGB image data and the geographical coordinates of the corresponding fruit trees. S2. Preprocess the acquired 3D point cloud information and RGB image data to extract key feature parameters of the fruit tree canopy, including the height, width, volume, leaf area density, and canopy tilt angle of the fruit tree canopy. S3. Conduct multiple pre-application tests, setting different operating conditions such as flight altitude, flight speed, outlet wind speed of the wind-driven centrifugal sprayer, and droplet size. Obtain the droplet deposition amount and ground liquid loss rate under each operating condition to form an experimental sample dataset. Input the experimental sample dataset and the extracted key feature parameters into the neural network model for training until the model converges or reaches the preset training index to obtain a trained fruit tree targeted pesticide application prediction model. Use this prediction model to determine the optimal pesticide application parameters. S4. Based on the determined optimal application parameters, the horizontal rotation angle, vertical deflection angle, outlet wind speed, and centrifugal atomizing nozzle speed of the plant protection drone's wind-driven centrifugal spraying device are adjusted in real time. Simultaneously, according to the actual location and volume of the fruit tree canopy and the drone's flight path, a circumferential target spraying mode is adopted, matched with a fixed-angle spraying mode or an up-and-down swing spraying mode. When the volume of the fruit tree canopy is less than the preset threshold, circumferential target spraying combined with fixed-angle spraying is used; when the volume of the fruit tree canopy is greater than the preset threshold, circumferential target spraying combined with up-and-down swing spraying is used to achieve precise target spraying and full coverage of the fruit tree canopy.

9. The method for precise target spraying using vector adjustment of agricultural drones according to claim 8, characterized in that, In step S2, the three-dimensional point cloud information is first preprocessed by denoising, downsampling, ground and trunk segmentation, and operation area division; multiple sets of RGB images are stitched, corrected and cropped to obtain remote sensing orthophotos; then, the three-dimensional point cloud data is identified and detected by clustering algorithm, and the remote sensing orthophotos are target detected and segmented by neural network segmentation model to complete the extraction of key feature parameters of fruit tree canopy and coordinate transformation.

10. The method for precise target spraying by vector adjustment of agricultural drones according to claim 8, characterized in that, In step S4, when the plant protection drone is operating forward, the outlet wind speed of the wind-driven centrifugal spraying device and the rotation speed of the centrifugal atomizing nozzle increase and then decrease, and increase and then decrease, depending on the density of the fruit tree canopy. The droplet size decreases and then increases accordingly. When the plant protection drone flies along the rows of fruit trees, the wind-driven centrifugal spraying device is deployed outward and the spray angle is perpendicular to the canopy slope. When the plant protection drone flies at the top of the canopy, the wind-driven centrifugal spraying device is deployed inward and the spray angle is perpendicular to the canopy slope. When the fruit tree canopy volume is small, a fixed angle spraying mode is used, maintaining a horizontal circling target, and the vertical spraying device axis is perpendicular to the canopy slope. When the canopy volume is large, an up-and-down swing spraying mode is used, maintaining a horizontal circling target, and the vertical spraying device swings smoothly along the canopy zoning lines.

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