Plant protection unmanned aerial vehicle liquid medicine automatic supply device and method

Abstract

The invention provides a plant protection unmanned aerial vehicle liquid medicine automatic supply device and method, and the device comprises a parking apron, a mobile platform, an embedded visual module, a liquid medicine supply mechanism, and a master controller. The plant protection unmanned aerial vehicle is actively identified by using the embedded vision module and the dynamic position of the plant protection unmanned aerial vehicle in a supply coordinate system is solved in real time by using the control technologies of visual identification of the embedded vision module, horizontal movement of the mobile platform, automatic liquid supply control of the liquid medicine supply mechanism and a master controller; and the position deviation between the actual landing position of the plant protection unmanned aerial vehicle and the preset landing point is obtained, the mobile platform is driven to complete position deviation correction, precise butt joint of the pesticide adding opening of the pesticide box of the plant protection unmanned aerial vehicle and the pesticide liquid supply mechanism is achieved, and automatic pesticide liquid supply is completed.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, specifically to an automatic pesticide refill device and method for agricultural UAVs. Background Technology

[0002] Currently, multi-rotor drones are the dominant type of agricultural drone in China. Compared to traditional ground-based agricultural machinery and manual spraying methods, multi-rotor agricultural drones offer advantages such as high spraying efficiency, strong maneuverability, and a high degree of automation, making them the preferred choice for agricultural socialized service cooperatives or large-scale grain growers. However, during large-scale agricultural operations, the frequent replenishment of pesticides poses a severe challenge to the workload of ground support personnel.

[0003] Currently, pesticide refilling for agricultural drones is mainly divided into two methods: manual and mechanized. Manual refilling involves manually pouring diluted pesticide solution (usually a bucket) directly into the drone's tank. This method is labor-intensive, has poor control precision, and is prone to pesticide leakage due to excessive instantaneous flow or operator negligence. It can also corrode important drone components, pollute farmland, and even endanger the health of operators. Mechanized refilling, on the other hand, uses a pump to inject pesticide solution into the drone's tank through a pipe. This reduces the labor intensity of ground personnel to some extent, but still relies on manual operation of the pump and handheld pipe, resulting in a low level of automation.

[0004] Automatic pesticide refilling for agricultural drones has enormous application prospects and development potential in improving the efficiency of plant protection operations and reducing labor costs. Patent application number 2020106443410 discloses a mobile automatic pesticide refilling system for agricultural drones, including a transport vehicle and a refilling component for replenishing pesticides on the drone. By manipulating a motor to change the position of a slider, the refill nozzle mounted on the slider is moved to the refill port of the drone's pesticide tank, thus achieving pesticide refilling. This device avoids personnel contact with pesticides during refilling, improving safety; however, the entire operation relies on mechanical devices, resulting in a low level of automation and intelligence. Patent application number 202210543948.6 discloses a fully automatic agricultural drone refilling platform, including a transport vehicle, a pesticide dispensing device, and a robotic arm. It details the automatic pesticide dispensing process in its structure but does not explain the specific scheme for aligning the refilling device with the drone's refill port to achieve automatic pesticide refilling. Patent application number 201810723936.5 discloses an automatic pesticide application device for drone plant protection, which applies pesticides to the drone by extending the pesticide application boom into the pesticide inlet of the drone's pesticide tank, but does not solve the problem of how to automatically align the pesticide application device with the pesticide inlet of the drone's pesticide tank.

[0005] Studies have shown that agricultural drones are affected by a variety of factors, including the absolute positioning error of the satellite navigation system, the drift error accumulated over time by the inertial navigation system, and instantaneous crosswinds. In autonomous return mode, the landing position often deviates from the preset landing point by several centimeters to tens of centimeters. Without adjusting the deviation, pesticide refilling is impossible, and existing technologies have not solved this technical problem. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides an automatic pesticide refill device and method for agricultural drones. It integrates visual recognition, motor drive, mechanical transmission, and microcontroller control technologies. Utilizing an embedded vision module, it actively identifies the agricultural drone, calculates its dynamic position in the refill coordinate system in real time, obtains the positional deviation between the drone's actual landing position and a preset landing point, and drives a mobile platform to correct the position. This achieves precise alignment between the drone's pesticide tank inlet and the pesticide refill mechanism, enabling automatic pesticide refilling.

[0007] To achieve the above technical objectives, the adopted technical solution is: an automatic pesticide refill device for agricultural drones, comprising: The helipad is equipped with a mobile platform. The mobile platform is used for landing agricultural drones and can move the agricultural drones horizontally on the landing pad. An embedded vision module, installed at the center of the mobile platform, is used to calculate the real-time position coordinates of the agricultural drone. Transmitted to the main controller; The medicine replenishment mechanism includes a medicine storage tank, a medicine pump, and a replenishment pipe connected in sequence. The replenishment port of the replenishment pipe is located at the preset medicine replenishment point. The pesticide pump is located directly above the pesticide tank filling port of the agricultural drone, and its start and stop are controlled by the main controller. The main controller collects the real-time location coordinates of the agricultural drone and calculates the deviation between the real-time location coordinates and the preset pesticide refill point coordinates. According to the deviation Control the mobile platform to move to the preset medicine replenishment point and drive the medicine replenishment mechanism to replenish the medicine.

[0008] The mobile platform achieves horizontal movement through a horizontal axis screw drive mechanism, a horizontal axis lever, a vertical axis screw drive mechanism (13), a vertical axis lever, and linear bearings. A set of linear bearings is installed on the lower surface of the horizontal axis and the vertical axis of the mobile platform. One end of the horizontal axis lever passes through the linear bearing on the horizontal axis, and the other end is fixedly connected to the slider of the horizontal axis screw drive mechanism, which is used to realize the movement of the mobile platform along the horizontal X-axis. One end of the vertical axis lever passes through the linear bearing on the vertical axis, and the other end is fixedly connected to the slider of the vertical axis screw drive mechanism, which is used to realize the movement of the mobile platform along the horizontal Y-axis.

[0009] The aforementioned drug supply mechanism includes a gantry-type supply pipe with a supply port and a rotating mechanism for adjusting the gantry-type supply pipe from a horizontal to a vertical position. The rotation direction of the rotating mechanism is controlled by a main controller. When the gantry-type supply pipe is in the vertical position, the supply port is positioned at the preset drug supply point. The position of the gantry-type liquid replenishment pipe is either below or level with the mobile platform, directly above the pesticide tank filling port of the agricultural drone.

[0010] The rotating mechanism is equipped with a self-locking stop device to ensure that the gantry-type replenishment tube remains in a vertical position during the replenishment of medicine.

[0011] The mobile platform is equipped with pressure sensors to detect whether the agricultural drone has landed on the mobile platform and whether the pesticide has been replenished. The pressure sensors are connected to the main controller to transmit real-time monitoring pressure.

[0012] The mobile platform is equipped with casters at its bottom to reduce the resistance to movement.

[0013] A method for refueling agricultural drones using an automatic pesticide refueling device includes the following steps: Step 1: When the agricultural drone lands on the mobile platform, the embedded vision module detects the agricultural drone using the agricultural drone recognition model and outputs the parameters of the target recognition bounding box. , To detect the horizontal and vertical pixel coordinates of the top-left corner of the bounding box in the image; To determine the width and height of the detection box, the center of the bounding box is calculated as the pixel coordinates of the agricultural drone. ; Step 2: Set the pixel coordinates of the agricultural drone Converting to world coordinates of agricultural drones ; Calculate the world coordinates of agricultural drones Coordinates of the preset medicine replenishment point deviation The main controller controls the movement of the mobile platform to eliminate positional deviations of the agricultural drone. Move the agricultural drone to the pre-designated pesticide refill point. ; Step 3: The agricultural drone moves to the pre-designated pesticide refill point. Then, the main controller sends a pesticide replenishment signal to the pesticide pump, which then delivers the pesticide from the storage tank to the pesticide tank of the agricultural drone via the replenishment pipe.

[0014] Before the agricultural drone lands on the mobile platform, the infusion tube is in a horizontal position. After the agricultural drone lands on the mobile platform, rotate and adjust the infusion tube to a vertical position so that the infusion port is aligned with the pesticide filling port of the agricultural drone.

[0015] The method for automatic drug replenishment mainly includes the following steps: Step 1: Install a pressure sensor connected to the main controller on the mobile platform to monitor pressure changes on the mobile platform in real time. The pressure increases after the agricultural drone lands; set a pressure threshold. ; Step 2: The main controller detects the pressure value. When the tube moves into position, a signal is sent to the rotating mechanism that can drive the replenishment tube to change from a horizontal position to a vertical position, adjust the replenishment tube to a vertical position, and then send a replenishment signal to the drug pump to start drug replenishment. Step 3: As the amount of pesticide solution in the agricultural drone's tank increases, the main controller detects through pressure sensors that the pressure on the mobile platform exceeds a preset threshold. It sends a stop drug supply signal to the drug pump and simultaneously drives the replenishment pipe to rotate to a horizontal position.

[0016] The beneficial effects of this invention are: 1. In the autonomous return mode of agricultural drones, the landing position often deviates by tens of centimeters from the preset landing point, causing misalignment between the pesticide dispensing device of the pesticide replenishment mechanism and the drone's pesticide tank opening, thus preventing automatic pesticide replenishment. This invention constructs a real-time dynamic recognition and positioning system based on embedded vision to acquire the drone's position coordinates in real time after landing. An automated device corrects the drone's position, and in conjunction with the coordinated control of the pesticide replenishment mechanism, precise alignment between the dispensing port and the drone's pesticide tank opening is achieved, enabling automatic pesticide replenishment.

[0017] 2. This application adopts a "land first, then position, then correct" method. The position correction program is initiated after the agricultural drone lands, avoiding various risks associated with in-flight attitude adjustments. Mechanical adjustments on the ground platform offer higher reliability and stability than in-flight attitude adjustments. This application's drone position correction scheme based on a ground-embedded vision module enables rapid drone positioning and automatic pesticide refilling, requiring less time and being more efficient than dynamic in-flight position adjustments.

[0018] 3. The infusion tube in this application is in a horizontal position before the agricultural drone lands, ensuring that it does not interfere with the drone's landing. After infusion, the tube returns to a horizontal position without affecting the drone's takeoff. Furthermore, the pressure sensor can detect whether the drone has landed and the progress of pesticide infusion. Compared to time-based automatic infusion, this method is more intelligent. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the horizontal axis lead screw drive mechanism of the present invention; Figure 3 This is a layout diagram of the lead screw drive mechanism and lever of the present invention; Figure 4 This is a schematic diagram of the operation of the horizontal axis lead screw drive mechanism and the horizontal axis lever of the present invention. Figure 5 This is a schematic diagram of the rotating mechanism and self-locking stop device of the present invention; Figure 6 This is a schematic diagram showing that the crank is in a horizontal state when the slider of the lead screw slider mechanism of the present invention is in extreme position 1; Figure 7 This is a schematic diagram showing that the crank is in a vertical state when the slider of the lead screw slider mechanism of the present invention is in extreme position 2; Figure 8 This is a schematic diagram of the position correction operation process of the present invention; Figure 9 This is a trend graph of the loss function during target recognition by the agricultural drone of this invention; Reference numerals: 1. Agricultural drone; 2. Embedded vision module; 3. Mobile platform; 4. Landing pad; 5. Infusion pipe; 6. Self-locking stop device; 601. Infusion stepper motor; 602. Screw-slider mechanism; 603. Side plate; 604. Stop motor; 605. Crank; 606. Support plate; 607. Pin; 608. Connecting rod; 7. Z-shaped support plate; 8. Pressure sensor; 9. Horizontal axis screw drive mechanism; 901. Horizontal axis stepper motor; 902. Coupling; 903. Screw; 904. Slide rail; 905. Slider; 906. Fixing bolt; 10. Linear bearing; 11. Horizontal axis lever; 12. Vertical axis lever; 13. Vertical axis screw drive mechanism; 14. Medicine storage tank; 15. Medicine pump; 16. Medicine tank filling port; 17. Infusion port. Detailed Implementation

[0020] The preferred embodiments of the invention are given below with reference to the accompanying drawings to illustrate the technical solution of the invention in detail. The corresponding drawings will be provided for detailed explanation of the invention. It should be particularly noted that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit or restrict the invention.

[0021] As attached Figure 1As shown, an automatic pesticide refill device for an agricultural drone includes an agricultural drone 1, an embedded vision module 2 for identifying the real-time position coordinates of the agricultural drone, a mobile platform 3 for correcting positional deviations of the agricultural drone, a landing pad 4 as the main support, a refill pipe 5, a self-locking stop device 6, a pressure sensor 8, a horizontal axis lead screw drive mechanism 9, a linear bearing 10, a horizontal axis lever 11, a vertical axis lever 12, a vertical axis lead screw drive mechanism 13, a pesticide storage tank 14, and a pesticide pump 15. The pesticide filling port 16 is located above the agricultural drone 1.

[0022] The helipad 4 has a mobile platform 3 installed on it. The main body of the helipad 4 is a square flat plate. The mobile platform 3 for the take-off and landing of agricultural drones and the auxiliary rollers below the mobile platform 3 are placed on the upper surface of the helipad.

[0023] The mobile platform 3 is a rectangular flat plate, preferably a square one. The agricultural drone 1 lands on the upper surface of the mobile platform 3, and its dimensions are smaller than those of the landing pad 4. Several rollers are evenly distributed on the lower surface of the mobile platform 3, and the drone moves horizontally across the upper surface of the landing pad using these rollers. The horizontal movement of the mobile platform 3 is achieved using conventional mechanical structures to move along the X and Y axes.

[0024] The medicine replenishment mechanism includes a medicine storage tank 14, a medicine pump 15, and a replenishment pipe 5 connected in sequence. The replenishment port 17 of the replenishment pipe 5 is located at the preset medicine replenishment point. The pesticide tank filling port 16 of the agricultural drone is directly above the pesticide pump 15, which is controlled by the main controller to start and stop.

[0025] The central controller collects the real-time location coordinates of the agricultural drone and calculates the deviation between the real-time location coordinates and the preset pesticide replenishment point coordinates. According to the deviation The mobile platform 3 is controlled to move to the preset medicine replenishment point, driving the medicine replenishment mechanism to replenish the medicine. The main controller can be an STM32 microcontroller, which will be described in detail below.

[0026] For example, the moving platform 3 achieves horizontal movement through the horizontal axis lead screw drive mechanism 9, the horizontal axis lever 11, the vertical axis lead screw drive mechanism 13, the vertical axis lever 12, and the linear bearing 10. The horizontal axis lead screw drive mechanism 9 is used to drive the moving platform 3 along the horizontal X-axis, and the vertical axis lead screw drive mechanism 13 is used to drive the moving platform 3 along the horizontal Y-axis. (See attached diagram) Figure 2As shown, the horizontal axis lead screw drive mechanism 9 includes a horizontal axis stepper motor 901, a coupling 902, a lead screw 903, a slide rail 904, a slider 905 with a threaded hole that engages with the lead screw for transmission, and a fixing bolt 906. The fixing bolt 906 is used to fix the entire horizontal axis lead screw drive mechanism 9 to the landing platform 4. One end of the lead screw 903 is connected to the output shaft of the horizontal axis stepper motor 901 through the coupling. Under the drive of the horizontal axis stepper motor 901, the slider 905 performs linear reciprocating motion along the slide rail 904 under the action of the lead screw 903. In this structure, the moving platform 3 transmits the number of pulses to the horizontal axis stepper motor 901 and the vertical axis stepper motor to realize the deviation adjustment. The angular displacement of the stepper motor is obtained by calculating the relationship between the angular displacement, the linear displacement of the slider, and the lead screw lead, and then the required number of stepper motor pulses is obtained from the angular displacement of the stepper motor.

[0027] As attached Figure 3 As shown, a set of linear bearings 10 are respectively installed on the lower surface of the moving platform 3 along its horizontal axis of symmetry and its vertical axis of symmetry. One end of the horizontal axis lever 11 passes through the horizontal axis linear bearing 10, and the other end is fixedly connected to the slider of the horizontal axis lead screw drive mechanism 9. Under the drive of the horizontal axis lead screw mechanism 9, the moving platform 3 moves along the horizontal axis (X-axis). One end of the vertical axis lever 12 passes through the vertical axis linear bearing and is fixedly connected to the slider of the vertical axis lead screw drive mechanism 13. Under the drive of the vertical axis lead screw mechanism 13, the moving platform 3 moves along the vertical axis (Y-axis).

[0028] As attached Figure 4 As shown, one end of the horizontal axis lever 11 is fixedly connected to the slider 905 of the horizontal axis lead screw drive mechanism 9, and the other end passes through the linear bearing 10. The linear bearing 10 is fixed on the horizontal axis of symmetry at the bottom of the moving platform 3. Under the push of the horizontal axis lever 11, the moving platform 3 is driven to make linear reciprocating motion along the longitudinal axis.

[0029] The medicine replenishment mechanism includes a gantry-type replenishment pipe 5 with a replenishment port 17 and a rotating mechanism for adjusting the gantry-type replenishment pipe 5 from a horizontal position to a vertical position. The rotation direction of the rotating mechanism is controlled by a main controller. When the gantry-type replenishment pipe 5 is in the vertical position, the replenishment port 17 is located at the preset medicine replenishment point. The gantry-type liquid replenishment pipe 5 is positioned directly above the pesticide tank filling port 16 of the agricultural drone, and when it is in a horizontal position, its position is lower than or level with the moving platform 3. The rotating mechanism is equipped with a self-locking stop device (6) to ensure that the gantry-type liquid replenishment pipe (5) is always in a vertical position during the liquid replenishment process.

[0030] The specific rotating mechanism and self-locking stop device 6 are shown in the attached figure. Figure 5As shown, a gantry-type replenishment pipe 5 is arranged along the transverse axis of symmetry of the helipad 4. The gantry-type replenishment pipe is fixedly installed on one end of the crank 605, and the position of the gantry-type replenishment pipe 5 is consistent with the position of the crank 605. The other end of the crank 605 is hinged to the transverse axis of symmetry of the helipad 4 via a pin 607, and rotates around the pin 607 under the push of the connecting rod 608. The connecting rod 608 is realized by a replenishment stepper motor driving a lead screw slider mechanism 602. One end of the connecting rod 608 is hinged to the slider of the lead screw slider mechanism 602, and the other end is hinged to one end of the replenishment pipe 5 of the crank 605. A side plate 603 is installed on the helipad 4, parallel to the rotation plane of the crank 605 and with a certain gap. A threaded through hole is opened on the side plate 603, and a stop screw is installed in the threaded through hole. One end of the stop screw is fixedly connected to the output shaft of the stop motor 604, which is mounted on a slide rail and can move horizontally (not shown in the figure). The crank 605 drives the gantry-type replenishment pipe 5 to rotate to a vertical position. At that time, the stop motor 904 receives a pulse signal from the STM32 microcontroller. This causes the stop screw to rotate clockwise and extend out of the threaded through hole under the action of the threaded through hole. A through hole is provided at a corresponding position on the crank 605 to mate with the stop screw. This through hole is a smooth hole, and the diameter of the smooth hole on the crank is slightly larger than the diameter of the threaded hole on the side plate 603, so that the stop screw can be smoothly inserted into the smooth hole of the crank, forming a stop device that locks the crank 605 together with the gantry-type replenishment pipe 5 in a vertical position. This ensures the precise alignment between the liquid replenishment port 17 and the pesticide filling port 16 of the drone's pesticide tank. After the agricultural drone 1 completes the pesticide replenishment, the stop motor 604 drives the stop screw to rotate counterclockwise and move horizontally on the slide rail under the action of the threaded through hole. The other end of the stop screw retracts backward from the crank hole, ending the self-locking stop function.

[0031] As attached Figure 6 As shown, when the slider of the lead screw-slider mechanism 602 is pulled back to its extreme position 1, the crank 606 is in a horizontal state. The gantry-type replenishment tube 5, which is fixedly connected together, is also in a horizontal position.

[0032] As attached Figure 7 As shown, the slider of the lead screw and slider mechanism 602 performs linear reciprocating motion, and the crank 605 rotates clockwise around the pin 607. When the slider of the lead screw and slider mechanism 602 is pushed forward to the limit position 2, the crank 606 is in a vertical state. The gantry-type replenishment tube 5, which is fixedly connected together, is also in a horizontal position.

[0033] As attached Figure 8As shown, after the agricultural drone 1 lands at any position on the mobile platform 3, the embedded vision module 2 obtains the position coordinates of the agricultural drone 1, and the STM32 microcontroller moves the agricultural drone 1 to the preset pesticide refill point by controlling the movement of the mobile platform 3.

[0034] As attached Figure 9 As shown, the embedded vision module 2 uses the agricultural drone recognition model to identify the agricultural drone 1. When the loss function stabilizes below the threshold, the model parameters are determined and the coordinate information is output.

[0035] The mobile platform 3 is also equipped with a pressure sensor 8 for detecting whether the agricultural drone has landed on the mobile platform 3 and whether the pesticide spraying has been completed. The pressure sensor 8 is connected to the main controller to transmit real-time pressure monitoring data. The pressure sensor 8 can be a thin-film pressure sensor.

[0036] A method for replenishing pesticide spraying fluid using an automatic pesticide spraying device for agricultural drones is disclosed. The automatic pesticide spraying device comprises the following core components and their connections: a landing pad 4 serves as the main support structure, and a horizontally movable platform 3 is mounted on the landing pad 4. The agricultural drone 1 lands at any position on the movable platform 1. An embedded vision module 2 is installed at the geometric center of the movable platform 3 to calculate the position coordinates of the agricultural drone 1 in real time. The vision module transmits the position coordinates of the agricultural drone to the STM32 microcontroller, which then calculates its position relative to the preset landing point. Positional deviation between And based on positional deviation The pulse signals Nx and Ny are respectively output to the controllers of the horizontal axis stepper motor of the horizontal axis lead screw drive mechanism 9 and the vertical axis stepper motor of the vertical axis lead screw drive mechanism 13. After receiving the commands from the controllers, the horizontal axis stepper motor and the vertical axis stepper motor output the corresponding angular displacement. and The system uses a lead screw mechanism to move the mobile platform, transporting the agricultural drone to the designated landing position. Eliminate the positional deviation of agricultural drones A pesticide refueling system is located on the side of the helipad. When the agricultural drone 1 lands on the mobile platform, a membrane pressure sensor detects that the pressure has increased from the no-load value. Increase to threshold At that time, the STM32 microcontroller outputs a pulse signal. The controller of the liquid replenishment stepper motor 601 drives the crank 605 to rotate clockwise, causing the gantry-type liquid replenishment tube 5 to rotate from a horizontal position to a vertical position. This positions the liquid replenishment port 17 of the liquid replenishment tube 5 directly above the pesticide inlet 16 of the agricultural drone's pesticide tank. A self-locking stop device 6 ensures that the liquid replenishment tube 5 remains in a vertical position throughout the pesticide replenishment process. When the liquid replenishment tube 5 reaches the vertical position, the STM32 microcontroller sends a pesticide replenishment signal to the pesticide pump 15. The pesticide pump 15 then delivers the pesticide from the storage tank 14 to the drone's pesticide tank via the liquid replenishment tube 5. As the amount of pesticide in the drone's pesticide tank increases, a thin-film pressure sensor detects that the platform pressure has reached a preset threshold. The STM32 microcontroller sends a stop drug supply signal to the drug pump 15, and simultaneously outputs a pulse signal to the controller of the replenishment stepper motor 601. The crank 605 is driven to rotate counterclockwise, causing the gantry-type liquid replenishment tube 5 to rotate to a horizontal position, so as to avoid affecting the subsequent take-off and landing of the agricultural drone.

[0037] The specific implementation process is as follows: First, the embedded vision module 2 identifies the position coordinates of the agricultural drone 1, thereby eliminating the positional deviation between the pesticide inlet 16 and the liquid replenishment inlet 17 of the agricultural drone's pesticide tank. This includes the following steps: Step 1: Acquire 2600 images of agricultural drones using an embedded vision module and create a dataset. Preprocess the dataset by cleaning and enhancing images to remove noisy, blurry, or overlapping images. Augment the dataset using operations such as rotation, cropping, mirroring, and contrast enhancement. Use LabelImg (an image annotation tool) to label the dataset, marking the locations of the agricultural drones on the bounding boxes of the images and labeling the drones as "drone," then save the dataset, completing the creation of the agricultural drone dataset.

[0038] Step 2: Establish an embedded vision module for agricultural drone recognition and train the model using the agricultural drone dataset from Step 1. The parameters are set as follows: input image size 224×224 pixels, number of iterations 240, batch size 8, maximum learning rate 0.001, and bounding box limit 5. The training, validation, and test sets are allocated in an 8:1:1 ratio, with 2080 images in the training set, 260 in the validation set, and 260 in the test set.

[0039] The optimal parameters of the agricultural drone recognition model are determined based on the loss function. (See attached image.) Figure 9As shown, during model training, when the number of iterations is less than 10, the loss function value drops rapidly to around 2; when the number of iterations is greater than 80, the loss rate slows down, indicating that the model training effect is good. As the number of iterations increases, the loss function decreases continuously. When the number of training iterations reaches 150, the loss function value has become stable and stabilizes at around 0.16. Training is then stopped and the optimal parameters of the model are saved to obtain the best agricultural drone recognition model.

[0040] Step 3: The agricultural drone lands at any location on the mobile platform. The embedded vision module uses the trained agricultural drone recognition model to identify the drone and outputs the bounding box parameters. ,Right now The pixel coordinates of the target center point are calculated through the following steps: In the formula: To detect the horizontal and vertical pixel coordinates of the top-left corner of the bounding box in the image; The width and height of the detection frame; These are the pixel coordinates of the target's center point.

[0041] Step 4: Convert the pixel coordinates of the agricultural drone to image coordinates. The embedded vision module obtains the pixel coordinates of the image with the top left corner of the image as the origin, while in image processing, the image center is often used as the origin. With the origin at a point, the x-axis and y-axis are parallel to the row and column coordinate systems of the image, respectively. The embedded vision module has a resolution of 320×240, therefore the center coordinates of the image can be determined. for The pixel sizes are respectively and Therefore, pixel coordinates to image coordinates The conversion formula is: Step 5: Based on the camera parameters, transform the coordinates of the agricultural drone in the image coordinate system. Camera coordinates The focal length of the camera is known to be... The conversion formula is: Step Six: Using the camera's extrinsic parameter matrix, determine the coordinates of the agricultural drone in the camera coordinate system. Convert to world coordinates This enables precise positioning of agricultural drones. The conversion formula is: Step 7: Based on the location coordinates of the agricultural drone obtained by the embedded vision module and the pre-set landing point The deviation between the agricultural drone and the preset pesticide refill point is calculated as follows: Step 8: Linear displacement of the horizontal and vertical axis levers and The location coordinates of the agricultural drone identified by the embedded vision module and the pre-set landing point Deviation between Confirmed, as shown in the following formula: Step Nine: Based on the linear displacement of the horizontal axis lever and the vertical axis lever and and lead screw Determine the rotation angles of the horizontal and vertical lead screws. and As shown in the following formula: Step 10: Based on the rotation angles of the horizontal and vertical lead screws... and Determine the angular displacement output by the horizontal axis stepper motor and the vertical axis stepper motor. and As shown in the following formula: Step 11: Based on the angular displacement of the horizontal axis stepper motor Angular displacement of the longitudinal axis stepper motor The lead screw pitch D and the step angle of the stepper motor Calculate the pulse signals of the horizontal axis stepper motor and the vertical axis stepper motor. , .

[0042] Therefore, the horizontal axis stepper motor and the vertical axis stepper motor receive pulse signals from the STM32 microcontroller. , Output angular displacement , The system uses a lead screw mechanism to move the mobile platform, transporting the agricultural drone to the designated landing position and eliminating any positional deviations. .

[0043] Furthermore, a thin-film pressure sensor is installed on the mobile platform to monitor pressure changes on the platform in real time. The no-load pressure is... When the agricultural drone lands on the mobile platform, the thin-film pressure sensor detects in real time that the pressure value exceeds the preset threshold of 450N, automatically triggering the pesticide refill enable signal. The pesticide refill steps are as follows: Step 1: The STM32 microcontroller compares the current pressure value. The system checks if the preset threshold of 450N is met to determine whether to trigger the fluid resuscitation process. When detected... At that time, a liquid replenishment enable signal is generated. Start the medicine supply mechanism. The formula is: Step 2: The liquid replenishment stepper motor 601 receives the liquid replenishment enable signal. After =1, rotate clockwise, and the angular displacement output by the lead screw of the lead screw-slider mechanism 601 is... Converted to linear displacement of the slider .

[0044] Step 3: When the slider is at its extreme position 1, the crank is in a horizontal state. At this point, the angle between the connecting rod and the horizontal plane is... .

[0045] Step 4: The slider moves linearly under the drive of the lead screw mechanism, which in turn drives the crank to rotate clockwise through the connecting mechanism. When the slider reaches the limit position 2, the crank is in a vertical position. At this point, the angle between the connecting rod and the horizontal plane is... .

[0046] Step 5: Linear displacement of the slider Based on the angle between the connecting rod and the horizontal plane , and the length of the connecting rod and the length of the crank Confirmed, as shown in the following formula.

[0047] Step Six: Based on the linear displacement of the slider Lead of the lead screw Determine the rotation angle of the lead screw As shown in the following formula: Step 7: Based on the rotation angle of the lead screw Determine the angular displacement output by the stepper motor ,Right now .

[0048] Step 8: Based on the angular displacement of the stepper motor and the step angle of the stepper motor Determine the number of pulses transmitted from the STM32 microcontroller to the stepper motor of the self-locking stop mechanism. As shown in the following formula: Step Nine: When the gantry-type replenishment pipe 5 is in a vertical position, the STM32 microcontroller sends a pesticide replenishment signal to the pesticide pump 15. The pump then delivers the pesticide from the storage tank to the pesticide tank of the agricultural drone 1 via the pipeline. As the amount of pesticide in the drone's pesticide tank increases, the STM32 microcontroller monitors the platform pressure through the thin-film pressure sensor 8 when it exceeds a preset threshold. =1030N, sends a stop drug supply signal to the drug pump, and simultaneously outputs a reverse pulse signal to the controller of the replenishment stepper motor 601. = 5379, drive the gantry-type liquid replenishment tube 5 to rotate counterclockwise to a horizontal position to avoid affecting the subsequent take-off and landing of the agricultural drone.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. An automatic pesticide refill device for agricultural drones, characterized in that, include: The helipad (4) is equipped with a mobile platform (3); The mobile platform (3) is used for the landing of agricultural drones and can drive the agricultural drones to move horizontally on the landing pad (4); The embedded vision module (2) is installed at the center of the mobile platform (3) and is used to calculate the real-time position coordinates of the agricultural drone. Transmitted to the main controller; The medicine replenishment mechanism includes a medicine storage tank (14), a medicine pump (15), and a replenishment pipe (5) connected in sequence. The replenishment port (17) of the replenishment pipe (5) is located at the preset medicine replenishment point. The pesticide tank filling port (16) of the plant protection drone is directly above the main controller, and the pesticide pump (15) is controlled to start and stop by the main controller. The main controller collects the real-time location coordinates of the agricultural drone and calculates the deviation between the real-time location coordinates and the preset pesticide refill point coordinates. According to the deviation Control the mobile platform (3) to move to the preset medicine replenishment point and drive the medicine replenishment mechanism to replenish the medicine.

2. The automatic pesticide refill device for agricultural drones as described in claim 1, characterized in that: The moving platform (3) moves horizontally via a horizontal axis screw drive mechanism (9), a horizontal axis lever (11), a vertical axis screw drive mechanism (13), a vertical axis lever (12), and a linear bearing (10). A set of linear bearings (10) is installed on the lower surface of the horizontal axis and the vertical axis of the moving platform (3). One end of the horizontal axis lever (11) passes through the linear bearing (10) on the horizontal axis, and the other end is fixedly connected to the slider of the horizontal axis screw drive mechanism (9) to realize the movement of the moving platform (3) along the horizontal X-axis. One end of the vertical axis lever (12) passes through the linear bearing (10) on the vertical axis, and the other end is fixedly connected to the slider of the vertical axis screw drive mechanism (13) to realize the movement of the moving platform (3) along the horizontal Y-axis.

3. The automatic pesticide refill device for agricultural drones as described in claim 2, characterized in that: The aforementioned drug supply mechanism includes a gantry-type replenishment pipe (5) with a replenishment port (17) and a rotating mechanism for adjusting the gantry-type replenishment pipe (5) from a horizontal position to a vertical position. The rotation direction of the rotating mechanism is controlled by a main controller. When the gantry-type replenishment pipe (5) is in the vertical position, the replenishment port (17) is located at the preset drug supply point. The gantry-type liquid replenishment pipe (5) is located directly above the medicine tank filling port (16) of the plant protection drone, and its position is lower than or level with the mobile platform (3) when the gantry-type liquid replenishment pipe (5) is in a horizontal position.

4. The automatic pesticide refill device for agricultural drones as described in claim 2, characterized in that: The rotating mechanism is equipped with a self-locking stop device (6) to ensure that the gantry-type liquid replenishment pipe (5) is always in a vertical position during the liquid replenishment process.

5. The automatic pesticide refill device for agricultural drones as described in claim 3, characterized in that: The mobile platform (3) is equipped with a pressure sensor (8) for detecting whether the plant protection drone has landed on the mobile platform (3) and whether the pesticide solution has been replenished. The pressure sensor (8) is connected to the main controller to transmit real-time monitoring pressure.

6. The automatic pesticide refill device for agricultural drones as described in claim 1, characterized in that: The mobile platform (3) is provided with rollers at the bottom to reduce the moving resistance of the mobile platform.

7. A method for replenishing pesticide solution using the automatic pesticide replenishment device for agricultural drones as described in claim 1, characterized in that... Specifically, it includes the following steps: Step 1: When the agricultural drone lands on the mobile platform (3), the embedded vision module (2) detects the agricultural drone through the agricultural drone recognition model and outputs the parameters of the target recognition bounding box. , To detect the horizontal and vertical pixel coordinates of the top-left corner of the bounding box in the image; To determine the width and height of the detection box, the center of the bounding box is calculated as the pixel coordinates of the agricultural drone. ; Step 2: Set the pixel coordinates of the agricultural drone Converting to world coordinates of agricultural drones ; Calculate the world coordinates of agricultural drones Coordinates of the preset medicine replenishment point deviation The main controller controls the movement of the mobile platform (3) to eliminate the positional deviation of the agricultural drone. Move the agricultural drone to the pre-designated pesticide refill point. ; Step 3: The agricultural drone moves to the pre-designated pesticide refill point. Then, the main controller sends a liquid replenishment signal to the liquid pump (15), and the liquid pump (15) delivers the liquid in the storage tank (14) to the medicine tank of the plant protection drone through the replenishment pipe (5).

8. A method for replenishing pesticide solution using an automatic pesticide replenishment device for agricultural drones as described in claim 7, characterized in that: Before the plant protection drone lands on the mobile platform, the infusion tube (5) is in a horizontal position. After the plant protection drone lands on the mobile platform, the infusion tube (5) is rotated and adjusted to a vertical position so that the infusion port (17) is aligned with the pesticide filling port (16) of the plant protection drone.

9. A method for replenishing pesticide solution using an automatic pesticide replenishment device for agricultural drones as described in claim 8, characterized in that: The method for automatic drug replenishment mainly includes the following steps: Step 1: Install a pressure sensor (8) connected to the main controller on the mobile platform (3) to monitor the pressure changes on the mobile platform (3) in real time. The pressure increases after the agricultural drone lands. Set the pressure threshold to 1. ; Step 2: The main controller detects the pressure value. When the tube moves into position, a signal is sent to the rotating mechanism that can drive the replenishment tube to change from a horizontal position to a vertical position, the replenishment tube is adjusted to a vertical position, and then a replenishment signal is sent to the drug pump (15) to start the drug replenishment; Step 3: As the amount of pesticide solution in the agricultural drone's tank increases, the main controller detects through pressure sensors that the pressure on the mobile platform exceeds a preset threshold. It sends a stop drug supply signal to the drug pump and simultaneously drives the replenishment pipe to rotate to a horizontal position.

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