Multi-rotor plant protection unmanned aerial vehicle based on precise pesticide application device

Abstract

This invention discloses a multi-rotor agricultural drone with adaptive spraying device adjustment, comprising a drone body, arms, a spraying device, a pesticide tank, and a control unit. The drone body has an internal slot for mounting the pesticide tank. The pesticide tank is equipped with a stirring device to ensure uniform mixing of the pesticide solution. This reduces pesticide sloshing within the tank and improves drone stability when the drone experiences instability, tilting, or roll due to internal or external disturbances. The spraying device can coordinate and control the nozzles according to changes in the external environment and different operating parameters, ensuring the spray direction is always aligned with the target area. Furthermore, the follow-up blades mounted on the spray boom reduce the adverse effects of the drone's rotor wind on the nozzle oscillation. This invention enables flexible adjustment of the drone's spray width, range, and spray angle, reduces the impact of pesticide sloshing within the tank on the drone's stability, and improves the droplet coverage and precision of the sprayed area.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, and specifically to a multi-rotor plant protection drone based on a precision spraying device. Background Technology

[0002] In recent years, my country's plant protection machinery has developed rapidly, and there are various plant protection operation methods. However, the area of ​​arable land in my country is more concentrated in mountainous, hilly, and plateau regions than in plains and basins. Therefore, considering factors such as pesticide utilization rate, plant protection operation needs, and the characteristics of arable land distribution, using plant protection drones to replace traditional machinery can complete plant protection operations in a more adaptable and flexible manner, and also has significant advantages in improving plant protection efficiency.

[0003] Due to the varied terrain and environment of fields and surrounding areas, agricultural drones inevitably encounter obstacles during field operations. To achieve safe and efficient operation, agricultural drones typically use obstacle avoidance maneuvers. This can lead to situations where crops around obstacles are under-sprayed or even missed, while crops on adjacent flight paths are sprayed repeatedly, making it difficult to guarantee the effectiveness of agricultural operations. Moreover, to avoid the impact of obstacles, agricultural drones may take off, land, stop suddenly, or turn, causing the pesticide solution in the tank to collide with the inner wall of the tank, interfering with the drone's flight attitude, reducing the coverage of the pesticide spray, and making it impossible to guarantee precise spraying in the field. Excessive shaking of the drone can also affect the uniformity of the pesticide solution, resulting in inconsistent pesticide concentrations sprayed on crops, which is detrimental to the control of pests and diseases in the field.

[0004] Existing agricultural drone spraying devices only focus on achieving a single function such as adjusting the spray width or spray angle, without considering the reverse impact of the drone rotor wind field on the spraying effect during the adjustment of the spray width and spray angle, as well as the impact of effective spray width and droplet penetration on the control effect of pests and diseases. They also fail to consider the problems that when the drone takes off, lands, stops suddenly, or turns to avoid obstacles, the pesticide liquid in the tank may collide with the inner wall of the tank, interfering with the drone's flight attitude, reducing the coverage of the pesticide spray, and failing to ensure accurate spraying in the field. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide a multi-rotor agricultural drone based on a precision spraying device. This addresses technical issues in existing technologies, such as drones experiencing flight attitude disturbances due to obstacle avoidance maneuvers involving ascents, descents, sudden stops, or turns, which affect pesticide coverage; pesticide residues in the tank easily swaying due to inertia, affecting pesticide mixing uniformity and spraying accuracy, and even causing drone flight instability; and the adverse effects of drone rotor wind on spraying effectiveness, leading to inaccurate pesticide application.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A multi-rotor agricultural drone based on a precision spraying device includes: a drone body, a pesticide tank, a spraying device, and a control unit; the drone body has multiple arms evenly spaced along its circumference, one end of each arm being fixedly connected to the drone body, and the upper side of the other end of each arm having a rotor for flight; a device slot is provided on the upper side of the drone body, extending downwards along the axis of rotation, and the pesticide tank is placed in this slot, with its lower side detachably fixedly connected to the slot; a stirring device is provided inside the pesticide tank for stirring the pesticide solution; landing gear is provided on opposite sides of the bottom of the drone body; and the bottom of the drone body... A carrying rack is located at the center of the unit. The lower side of the carrying rack is fixedly connected to the landing gear, and the drone body is placed on top of the carrying rack and detachably fixedly connected to it. A visual camera and two sets of lidar are located on the front side of the carrying rack, and both the visual camera and lidar are detachably fixedly connected to the carrying rack. A control unit and multiple sets of batteries are located on the rear side of the carrying rack. The spraying device is installed on two opposing arms in the middle of the drone body. The control unit can obtain the crop density through the visual camera and lidar, and detect the crop pest and disease status. Then, based on the detection results, it controls the spraying device to adaptively change the spray width and adjust the spray angle to complete the plant protection operation in a targeted manner.

[0008] Preferably, the medicine box includes a lid, an annular washer, a box body, and a medicine inlet. Multiple mounting protrusions are distributed around the lid, and the lid is detachably and fixedly connected to the box body via bolts I and the mounting protrusions. The medicine inlet is located at the upper center of the box body and communicates with the interior of the box body for medicine delivery. A sealing groove is provided on the side of the lid opposite to the box body, and an annular washer is provided within the sealing groove. The annular washer seals the contact surface between the lid and the box body, preventing medicine leakage during drone flight. The bottom shape of the box body complements the internal structure of the drone body, allowing the medicine box to be embedded into the drone body, thus making the installation of the medicine box on the drone body more stable and reliable.

[0009] Preferably, the stirring device includes a lead screw, a geared motor, a transmission mechanism, multiple stirrers, and multiple wall scrapers; wherein, the transmission mechanism is located inside the medicine tank and is fixedly connected to the inner wall of the medicine tank; the geared motor is located above the transmission mechanism, and the drive end of the geared motor is connected to the transmission mechanism, enabling the geared motor to drive the transmission mechanism to rotate, providing power to the entire stirring device; the lead screw is located inside the medicine tank, one end of the lead screw is connected to the transmission mechanism, and the other end extends to the bottom of the medicine tank and is rotatably connected to the bottom of the medicine tank, and the geared motor can drive the lead screw to rotate through the transmission mechanism. Its own axis rotates; the geared motor is connected to multiple agitators and multiple wall scrapers through a transmission mechanism, so that the drive motor can drive the agitators and wall scrapers to rotate on their own axis and rotate around the lead screw axis through the transmission mechanism; a movable plate is sleeved on the outside of the lead screw, the movable plate is rotatably connected to the lead screw and can move along the length direction of the lead screw, the edge of the movable plate extends to the inner wall of the medicine box and flexibly contacts the inner wall of the medicine box; the geared motor drives the lead screw to rotate around the axis of the lead screw through the transmission mechanism, so that the movable plate can reciprocate along the length direction of the lead screw.

[0010] Preferably, the transmission mechanism includes a support plate, a transmission shaft, a gear ring, a sun gear, and multiple planetary gears. The support plate is located inside the medicine tank and is fixedly connected to the inside of the tank cover by bolts II. A circular opening is formed in the middle of the support plate, penetrating the support plate. The gear ring is located inside the opening and fixedly connected to it, with its center line coinciding with the axis of the transmission shaft. A motor mounting base is provided above the support plate, and the motor mounting base is fixedly connected to the support plate. A reduction motor is fixedly connected to the motor mounting base. One end of the lead screw is driven by the transmission shaft to the drive end of the reduction motor, allowing the reduction motor to drive the lead screw to rotate around its axis. The drive end of the reduction motor is connected to the top end of the transmission shaft via coupling II, thereby driving the transmission shaft to rotate and providing power to the entire stirring device. The lower end of the transmission shaft is mechanically connected to the lead screw via coupling I. Coupling I, coupling II, and the transmission shaft ensure the stability of the reduction motor driving the lead screw during rotation, reducing the frequency of failures. The sun gear is sleeved on the outside of the drive shaft and fixedly connected to the drive shaft, enabling the sun gear to rotate around its own axis. Both the sun gear and planet gears are located within the gear ring, and the sun gear, planet gears, and the inner side of the gear ring are meshed together. A planet carrier is also provided above the support plate, sleeved on the outside of the drive shaft and rotatably connected to it. The upper side of the planet gears is rotatably connected to the lower side of the planet carrier. Specifically, by simultaneously meshing with the sun gear and the gear ring, the planet gears can revolve around the sun gear while also rotating around their own axis. The planet carrier ensures the stability of the planet gears' operation, enabling them to stably achieve the aforementioned movements. When the geared motor drives the drive shaft to rotate around its own axis, the drive shaft, through the sun gear, drives the planet gears to rotate within the gear ring. The sun gear rotates around the axis of the drive shaft within the gear ring, and the planet gears move circumferentially within the gear ring while also rotating around their own axes. The top of the agitator and the top of the scraper are fixedly connected to the lower side of the planet gears, allowing the agitator and scraper to move with the planet gears. Therefore, when the drive shaft drives the sun gear and the planet carrier installed between the drive shaft and the sun gear to rotate, the planet gears both rotate on their own axes and revolve around the sun gear; preferably, there are 4 planet gears, which are evenly distributed along the circumference of the sun gear, so that the sun gear and planet gears can be more stable during operation.

[0011] Preferably, the transmission ratio between the sun gear and the planetary gears is greater than 1. Because the transmission ratio between the sun gear and the planetary gears is greater than 1, the sun gear and the planetary gears operate with differential speed transmission, causing the lead screw to drive the movable plate to rotate and lift along its length. When the movable plate moves, its lower surface is always close to the liquid surface, which reduces the space for liquid sloshing and also cleans the liquid from the inner wall of the tank.

[0012] Preferably, multiple fixed rods are provided below the movable plate. The upper end of the fixed rod is fixedly connected to the movable plate, and the lower end of the fixed rod is connected to the float plate through a spherical joint. When the liquid medicine shakes, the inertial force acts on the float plate, and the force generated by the liquid medicine is dissipated by the shaking of the float plate, thereby avoiding the inertial force of the liquid surface from impacting the tank body.

[0013] Preferably, multiple guide holes I are provided on the float plate so that the medicine liquid in the medicine tank can flow through the guide holes I, which can effectively reduce the lateral swaying of the medicine liquid due to inertia and ensure the stability of the medicine tank.

[0014] Preferably, the wall scraper includes a connecting rod I, the upper end of which passes through the movable plate and is fixedly connected to the lower side of the planetary gear; the lower end of the connecting rod I is provided with a plurality of spiral stirring blades I, the upper end of which is fixedly connected to the connecting rod I, and the lower end of which is provided with an elastic scraper, which flexibly contacts the inner wall of the bottom of the medicine tank. When the wall scraper moves, the elastic scraper can continuously scrape up the medicine liquid that has settled at the bottom of the tank, ensuring the uniformity of the medicine liquid in the tank.

[0015] Preferably, the stirrer includes a connecting rod II, the upper end of which passes through the movable plate and is fixedly connected to the lower side of the planetary gear; the lower end of the connecting rod II is provided with a plurality of stirring blades II, which are spaced apart along the length of the connecting rod II, and one end of the stirring blade II is fixedly connected to the connecting rod II, while the other end extends into the medicine tank; the stirring blade II is provided with a plurality of guide holes II, so that the medicine liquid in the medicine tank can flow through the guide holes II, effectively reducing the continuous shaking of the medicine liquid in the vertical direction.

[0016] Preferably, the spraying device includes multiple mounting bases, a linear module, a rotating mechanism, a swinging mechanism, follower blades, a nozzle, and a monitoring module; the linear module is located below the boom, its length direction is consistent with the length direction of the boom, and it is fixedly connected to the boom through multiple mounting bases; the linear module includes a drive mechanism I, the drive end of which is fixedly connected to the rotating mechanism, and the drive mechanism I can drive the rotating mechanism to slide along the length direction of the boom; the rotating mechanism includes a drive mechanism II, which can cause the rotating end of the rotating mechanism to rotate around the axis of the rotating end, and the rotating end of the rotating mechanism is fixedly connected to the swinging mechanism, and the rotating mechanism can cause the swinging mechanism to rotate around the axis of the rotating end. The axis of the end rotates; the swing mechanism includes a drive mechanism III, and the swing end of the swing mechanism is rotatably connected to the swing mechanism via a rotating shaft. The drive mechanism III can drive the swing end of the swing mechanism to swing around the axis of the rotating shaft; the follower blade is located between the nozzle and the swing mechanism, and the follower blade can rotate around the center line of the nozzle under the drive of the drive mechanism IV, providing the nozzle with an air field consistent with its spraying direction; the medicine tank is connected to the nozzle through a medicine delivery pipe; the monitoring module includes multiple distance sensors and angle sensors. The distance sensors monitor the moving distance of the nozzle, and the angle sensors monitor the rotation angle of the rotating end of the rotating mechanism and the swing angle of the swing end of the swing mechanism.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The multi-rotor agricultural drone based on a precision spraying device described in this invention reduces the swaying amplitude between the spray tank and the drone body during flight by embedding the spray tank body into the drone body, making the spray tank installation more stable and reliable. Simultaneously, during drone operation, sudden stops, sharp turns, and speed transitions may occur, causing the pesticide solution to sway continuously within the spray tank due to changes in the drone body. This further affects the drone's flight attitude, thus impacting the accuracy of spraying. The drone described in this invention utilizes a planetary mixing device, where the agitator and scraper rotate and revolve to slowly stir the pesticide solution, counteracting the swaying. The elastic scraper on the scraper can also scrape up the pesticide solution that has settled at the bottom of the tank, improving the uniformity of pesticide mixing.

[0019] 2. The multi-rotor agricultural drone based on a precision spraying device described in this invention uses a nut installed at the center of the movable plate to cooperate with the lead screw, allowing the movable plate to move with the lead screw. Since the transmission ratio between the sun gear and the planetary gears is greater than 1, the sun gear and the planetary gears perform differential transmission. The movable plate is also fitted onto the agitator and scraper, which are driven by planetary gears. Therefore, by controlling the forward and reverse rotation of the motor, the lead screw and nut can drive the movable plate to rotate and lift. At this time, the lower surface of the movable plate is always close to the liquid surface, compressing the space for liquid sloshing and achieving the purpose of cleaning the residual liquid on the tank.

[0020] 3. The multi-rotor plant protection drone based on a precision spraying device described in this invention uses a design where four floats are connected below the movable plate in a spherical pair manner. When the pesticide solution sloshes, the inertial force is applied to the floats, and the force generated by the pesticide solution is dissipated by the sloshing of the floats, thereby effectively preventing the liquid surface from impacting the tank surface. Furthermore, the guide holes opened on the floats and the agitator can effectively reduce the lateral continuous sloshing of the pesticide solution, ensuring the stability and firmness of the pesticide tank.

[0021] 4. The multi-rotor agricultural drone based on a precision spraying device described in this invention uses a control unit to determine the distance to the target object based on a lidar and a visual camera, and then controls a linear movement module to dynamically adjust the spray width of the agricultural drone. When the drone encounters obstacles and flies to avoid them, it can adaptively adjust the nozzle angle according to the obstacle avoidance route and the relative distance between the drone and the obstacle, so that the spraying direction is always towards the target area. In order to reduce the influence of the vertical wind field of the drone rotor on the spraying effect when the nozzle swings, a follower blade is provided on the spray boom. The wind field generated by the follower blade is always consistent with the spraying direction of the nozzle, so as to improve the coverage of pesticide and the control effect of pests and diseases. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a multi-rotor agricultural drone based on a precision spraying device according to the present invention.

[0023] Figure 2 This is a top view of a multi-rotor agricultural drone based on a precision spraying device according to the present invention.

[0024] Figure 3 for Figure 2 View from direction A.

[0025] Figure 4 for Figure 2 View from direction B in the middle.

[0026] Figure 5 This is a top view of the unmanned aerial vehicle medicine box 3 described in this invention.

[0027] Figure 6 for Figure 5 A sectional view along the C-axis.

[0028] Figure 7 for Figure 6 Top view of the central movable panel 330.

[0029] Figure 8 for Figure 7 A sectional view along the D direction.

[0030] Figure 9 for Figure 3A schematic diagram of the structure of the spray device 5.

[0031] In the diagram: 1. UAV fuselage; 2. Arm; 3. Medicine tank; 4. Carrying rack; 5. Spraying device; 6. Landing gear; 7. LiDAR; 8. Visual camera; 9. Control unit; 10. Battery pack; 31. Tank cover; 32. Mixing device; 33. Support plate; 34. Bolt I; 35. Bolt II; 36. Annular washer; 37. Tank body; 38. Medicine inlet; 321. Gear motor; 322. Motor mounting bracket; 323. Planetary carrier; 324. Planetary gears; 325. Coupling I; 326. Wall scraper. 3261 Mixing blade I, 3262 Elastic scraper, 327 Lead screw, 328 Agitator, 3281 Mixing blade II, 329 Gear ring, 330 Movable plate, 3301 Float plate, 3302 Elastic sleeve, 331 Nut, 332 Drive shaft, 333 Coupling II, 334 Sun gear, 501 Rotating mechanism, 502 Follower blade, 503 Nozzle, 504 Swinging mechanism, 505 Monitoring module, 506 Mounting base, 507 Linear module. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the present invention are within the scope of protection of the present invention.

[0033] This invention provides a multi-rotor agricultural drone based on a precision spraying device, such as... Figure 1-9As shown, the drone includes: a drone body 1, a medicine tank 3, a spraying device 5, and a control unit 9. The drone body has multiple arms 2 evenly spaced along its circumference, with one end of each arm fixedly connected to the drone body and a rotor for flight mounted on the upper side of the other end. A device slot is located on the upper side of the drone body, extending downwards along the axis of flight. The medicine tank is placed within this slot, and its lower side is detachably and fixedly connected to the slot. A stirring device 32 is located inside the medicine tank to stir the liquid medicine. Landing gears 6 are located on opposite sides of the bottom of the drone body. A cargo rack 4 is located at the center of the bottom of the drone body, with its lower side fixedly connected to the landing gear. The drone body is placed on top of the cargo rack and detachably and fixedly connected to it. The rotors on the arms and the landing gear enable the drone to take off, fly, and land. A visual camera 8 and two sets of lidar 7 are installed on the front side of the carrying frame, and both the visual camera and lidar are detachably and fixedly connected to the carrying frame. A control unit 9 and multiple sets of batteries 10 are installed on the rear side of the carrying frame. The spraying device 5 is installed on two opposing arms in the middle of the drone body. The control unit can obtain the crop density through the visual camera and lidar, and detect the crop pest and disease status. Then, based on the detection results, it controls the spraying device to change the spray width and adjust the spraying angle to complete the targeted plant protection operation.

[0034] In some embodiments, the medicine box 3 includes a lid 31, an annular washer 36, a box body 37, and a medicine inlet 38. Multiple mounting bosses are distributed around the lid, and the lid is detachably and fixedly connected to the box body by bolts I 34 and the mounting bosses. The medicine inlet is located at the upper center of the box body and communicates with the interior of the box body for medicine delivery. A sealing groove is provided on the side of the lid opposite to the box body, and an annular washer is provided within the sealing groove. The annular washer seals the contact surface between the lid and the box body. The bottom shape of the box body complements the internal structure of the UAV body 1, allowing the medicine box to be embedded in the UAV body, thereby reducing the shaking between the medicine box and the UAV body during flight and improving the overall stability of the UAV.

[0035] In some embodiments, the stirring device 32 includes a lead screw 327, a geared motor 321, a transmission mechanism, multiple stirrers 328, and multiple wall scrapers 326. The transmission mechanism is located inside the medicine tank and is fixedly connected to the inner wall of the medicine tank. The geared motor 321 is located above the transmission mechanism, and its drive end is connected to the transmission mechanism, enabling the geared motor to drive the transmission mechanism to rotate. The lead screw is located inside the medicine tank, with one end connected to the transmission mechanism and the other end extending to the bottom of the medicine tank, rotatably connected to the bottom of the medicine tank. In specific implementations, one end of the lead screw is connected to the transmission shaft of the transmission mechanism via a coupling, and the other end extends to the bottom of the medicine tank, rotatably connected to the bottom of the medicine tank. The geared motor can drive the lead screw to rotate around its own axis via the transmission shaft. The geared motor is connected to the multiple stirrers and multiple wall scrapers via the transmission mechanism, enabling the geared motor to drive the stirrers and wall scrapers to rotate on their own axes while simultaneously rotating around the axis of the lead screw. This method of slowly stirring the liquid medicine serves two purposes: firstly, it ensures uniform mixing, preparing the medicine for application; secondly, it counteracts the sloshing of the liquid medicine in the tank due to inertia during drone operations, such as sudden stops, sharp turns, and rapid speed changes, thus ensuring the stability of the drone during flight. A movable plate 330 is fitted around the outside of the lead screw. This movable plate is rotatably connected to the lead screw and can move along the length of the lead screw. The edge of the movable plate extends to the inner wall of the tank and makes flexible contact with the inside of the tank. When the geared motor drives the lead screw to rotate around its axis via the transmission mechanism, the movable plate can reciprocate along the length of the lead screw. When the movable plate moves, its lower surface is always close to the liquid surface, which reduces the space for liquid medicine sloshing and also cleans the liquid medicine from the inner wall surface of the tank.

[0036] Based on the above embodiment, the transmission mechanism includes a support plate 33, a transmission shaft 332, a gear ring 329, a sun gear 334, and multiple planetary gears 324. The support plate is located inside the medicine tank and is fixedly connected to the inside of the medicine tank, i.e., the inside of the tank cover, by bolts II 35. A circular opening is formed in the middle of the support plate, which penetrates the support plate. The gear ring is located inside the opening and is fixedly connected to the opening, and the center line of the gear ring coincides with the axis of the transmission shaft. A motor mounting base 322 is provided above the support plate, and the motor mounting base is fixedly connected to the support plate. A reduction motor is fixedly connected to the motor mounting base. One end of the lead screw is driven by the transmission shaft 332 to the drive end of the reduction motor, and the reduction motor can drive the lead screw to rotate around its axis through the transmission shaft. The drive end of the reduction motor is driven by coupling II 333 to the top end of the transmission shaft, thereby driving the transmission shaft to rotate and providing power to the entire stirring device. The lower end of the drive shaft is mechanically connected to the lead screw via coupling I 325. Coupling I, coupling II, and the drive shaft ensure the stability of the lead screw rotation driven by the geared motor, reducing the frequency of failures. The sun gear is sleeved on the outside of the lead screw and fixedly connected to it, allowing the sun gear to rotate around the axis of the lead screw. Both the sun gear and planet gears are located inside the gear ring, and the sun gear and planet gears are meshed with the inner side of the gear ring. A planet carrier 323 is also provided above the support plate. The planet carrier is sleeved on the outside of the drive shaft and rotatably connected to it. The upper side of the planet gears is rotatably connected to the lower side of the planet carrier. Specifically, by meshing with both the sun gear and the gear ring, the planet gears can revolve around the sun gear while also rotating around their own axes. The planet carrier ensures the stability of the planet gears, enabling them to stably achieve the aforementioned movements. This can be achieved by combining a stirrer and a scraper. The upper ends of both the stirrer and the scraper pass through their corresponding planetary gears and extend upwards to the lower side of the planetary carrier, where they are rotatably connected. Both the stirrer and the scraper are fixedly connected to the planetary gears, thus achieving a rotatable connection between the upper side of the planetary gears and the lower side of the planetary carrier. When the geared motor drives the transmission shaft to rotate around its own axis, the transmission shaft, through the sun gear, drives the planetary gears to rotate within the gear ring. The sun gear rotates around its own axis within the gear ring, while the planetary gears move circumferentially within the gear ring and also rotate around their axes. The tops of the stirrer and the scraper are fixedly connected to the lower sides of the planetary gears, allowing the stirrer and scraper to move with the planetary gears. Preferably, there are four planetary gears, evenly spaced along the circumference of the sun gear, to ensure greater stability during operation. The transmission ratio between the sun gear and the planetary gears is greater than 1, thus the sun gear and planetary gears operate with differential speed, causing the lead screw to drive the movable plate to rotate and lift along its length. When the movable plate moves, its lower surface is always close to the liquid surface, which can reduce the space for liquid to slosh and clean the liquid on the surface of the tank 37.

[0037] In some embodiments, multiple fixed rods are provided below the movable plate 330. The upper ends of the fixed rods are fixedly connected to the movable plate, and the lower ends of the fixed rods are connected to the float plate 3301 through a spherical joint. Multiple guide holes I are provided on the float plate 3301, allowing the liquid medicine in the medicine tank 3 to flow through the guide holes I. Among them, four float plates 3301 are connected to the movable plate below the spherical joint. When the liquid medicine shakes, the inertial force acts on the float plates, and the force generated by the liquid medicine is dissipated by the shaking of the float plates, thereby avoiding the inertial force of the liquid surface from impacting the tank body; at the same time, in conjunction with the guide holes I designed on the float plates, the lateral swaying of the liquid medicine due to inertia can be effectively reduced, ensuring the stability of the medicine tank 3.

[0038] In some embodiments, the wall scraper 326 includes a connecting rod I, the upper end of which passes through a movable plate and is fixedly connected to the lower side of the planetary gear; the lower end of the connecting rod I is provided with a plurality of spiral stirring blades I 3261, the upper end of which is fixedly connected to the connecting rod I, and the lower end of which is provided with an elastic scraper 3262, which flexibly contacts the inner wall of the bottom of the medicine tank 3. The stirrer 328 includes a connecting rod II, the upper end of which passes through a movable plate and is fixedly connected to the lower side of the planetary gear; the lower end of the connecting rod II is provided with a plurality of stirring blades II 3281, which are spaced apart along the length of the connecting rod II, with one end of the stirring blade II fixedly connected to the connecting rod II and the other end extending into the medicine tank; the stirring blades II 3281 are provided with a plurality of guide holes II, allowing the liquid medicine in the medicine tank 3 to flow through the guide holes II. Specifically, the wall scraper and agitator are alternately installed at the center of the four planetary gears. As the planetary gears rotate on their own axes and revolve around the sun gear, the wall scraper and agitator can achieve two mixing methods, thereby improving the uniformity of the medicine solution mixing in the tank. The guide hole II on the agitator II can effectively reduce the continuous sloshing of the medicine solution in the vertical direction. The elastic scraper 3262 installed at the bottom of the wall scraper 326 moves with the wall scraper 326, which can continuously scrape up the medicine solution that has settled at the bottom of the tank 37, ensuring the uniformity of the medicine solution in the tank 3.

[0039] In some embodiments, the spraying device 5 includes multiple mounting bases 506, a linear module 507, a rotating mechanism 501, a swing mechanism 504, follow-up blades 502, a nozzle 503, and a monitoring module 505. The linear module is located below the arm 2, its length direction is consistent with the length direction of the arm, and it is fixedly connected to the arm through multiple mounting bases. The linear module includes a drive mechanism I, the drive end of which is fixedly connected to the rotating mechanism. The drive mechanism I can drive the rotating mechanism to slide along the length direction of the arm. When the drive mechanism I of the linear module is driven, the rotating mechanism can slide within the linear thread of the linear module. At the same time, the drive mechanism I, in conjunction with the monitoring module, can control the sliding distance of the rotating mechanism, so that the rotating mechanism can stop precisely at the required position and lock the rotating mechanism at that position to prevent the position of the rotating mechanism from changing during application. The rotating mechanism includes a drive mechanism II, which enables the rotating end of the rotating mechanism to rotate around its axis, i.e., the rotating end of the rotating mechanism can rotate 360°. The rotating end of the rotating mechanism is fixedly connected to a swing mechanism, which enables the swing mechanism to rotate around its axis. When the drive mechanism II drives the rotating mechanism, the rotating end of the rotating mechanism drives the connected swing mechanism to rotate 360°. Subsequently, when the rotating end of the rotating mechanism rotates to the desired angle, the drive mechanism II locks the rotating end of the rotating mechanism at this angle to prevent the angle of the rotating end of the rotating mechanism from changing during the application of the pesticide. The swing mechanism includes a drive mechanism III, whose swing end is rotatably connected to the swing mechanism via a rotating shaft. The drive mechanism III drives the swing end of the swing mechanism to swing around the axis of the rotating shaft. The nozzle is mounted on the swing end of the swing mechanism. When the drive mechanism III of the swing mechanism is activated, the swing end of the swing mechanism swings back and forth or left and right around the axis of the rotating shaft. Simultaneously, the nozzle adjusts its angle accordingly. After the nozzle swings to the desired angle, the drive mechanism III locks the swing end of the swing mechanism at that angle to prevent changes in the angle. The follower blade is located between the nozzle and the swing mechanism, and can rotate around the centerline of the nozzle under the drive mechanism IV, providing the nozzle with an airflow consistent with its spray direction. The medicine tank is connected to the nozzle via a medicine delivery pipe. The monitoring module includes multiple distance sensors and angle sensors. The distance sensors monitor the movement distance of the nozzle 503, and the angle sensors monitor the rotation angle of the rotating end of the rotating mechanism 501 and the swing angle of the swing end of the swing mechanism 504.In practical use, the drone uses the visual camera 8 to detect the density of crops and the status of pests and diseases, and feeds the data back to the control unit 9. The control unit then manipulates the rotating mechanism to slide within the thread of the linear module, thereby adaptively adjusting the nozzle spray pattern and spray range, and ensuring that the center of the nozzle is aligned with areas with high crop density or relatively severe pests and diseases. When the drone performs obstacle avoidance operations, the lidar 7 can detect the relative distance between the drone body 1 and obstacles in real time and feed it back to the control unit. The control unit then adaptively adjusts the nozzle angle by manipulating the rotating and swinging mechanisms, ensuring that the nozzle is always aligned with the vicinity of the obstacle. The system can fix the nozzle at the adjusted angle, ensuring its position remains unchanged during application and continuous spraying. Furthermore, while the nozzle is spraying, the control unit controls the rotation of the follower blades to generate a wind field. This wind field reduces the impact of the drone's rotor rotation on the nozzle's linear or oscillating operation. Simultaneously, the control unit can further control the positions of the nozzle, rotor, and follower blades. When the nozzle and rotor are coaxial, the wind field generated by the follower blades overlaps with the rotor's wind field, improving pesticide penetration and enhancing the drone's spraying effectiveness.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A multi-rotor agricultural drone based on a precision spraying device, characterized in that, The drone includes: drone body (1), medicine tank (3), spray device (5) and control unit (9); the drone body is provided with multiple arms (2) evenly spaced along the circumference of the body, and one end of the arm is fixedly connected to the drone body, and the upper side of the other end of the arm is provided with a rotor for flight. The upper side of the drone body is provided with a device slot, which extends downward from the upper side of the body along the axial direction. The medicine box is placed in the device slot, and the lower side of the medicine box is detachably and fixedly connected to the device slot. A stirring device (32) is provided inside the medicine box, which is used to stir the medicine liquid in the medicine box; A landing gear (6) is provided on the bottom of the drone body and on both sides opposite to each other; a cargo rack (4) is provided at the center of the bottom of the drone body, the lower side of the cargo rack is fixedly connected to the landing gear, and the drone body is placed on the cargo rack and detachably fixedly connected to it. A visual camera (8) and two sets of lidar (7) are provided on the front side of the shelf. The visual camera and lidar are detachably and fixedly connected to the shelf. A control unit (9) and multiple sets of batteries (10) are provided on the rear side of the shelf. The spraying device (5) is installed on two opposing arms in the middle of the drone body; the control unit can obtain the density of crops through a visual camera and lidar, and detect the status of crop diseases and pests. Then, based on the detection results, it controls the spraying device to change the spray width and adjust the spraying angle to complete the plant protection operation task in a targeted manner. The stirring device (32) includes a lead screw (327), a geared motor (321), a transmission mechanism, multiple stirrers (328) and multiple wall scrapers (326). The transmission mechanism is located inside the medicine box and is fixedly connected to the inner wall of the medicine box; the geared motor is located above the transmission mechanism, and the drive end of the geared motor is connected to the transmission mechanism, so that the geared motor can drive the transmission mechanism to rotate; the lead screw is located inside the medicine box, one end of the lead screw is connected to the transmission mechanism, and the other end extends to the bottom of the medicine box and is rotatably connected to the bottom of the medicine box, so that the geared motor can drive the lead screw to rotate around the axis of the lead screw through the transmission mechanism. The geared motor is connected to multiple agitators and multiple wall scrapers through a transmission mechanism. The geared motor can drive the agitators and wall scrapers to rotate on their own axis and rotate around the lead screw axis through the transmission mechanism. A movable plate (330) is sleeved on the outside of the lead screw. The movable plate is rotatably connected to the lead screw and can move along the length direction of the lead screw. The edge of the movable plate extends to the inner wall of the medicine box and flexibly contacts the inner wall of the medicine box. The geared motor drives the lead screw to rotate around the axis of the lead screw through the transmission mechanism, so that the movable plate can reciprocate along the length direction of the lead screw.

2. The multi-rotor crop protection unmanned aerial vehicle based on the precise pesticide application device according to claim 1, characterized in that: The medicine box (3) includes a lid (31), an annular gasket (36), a box body (37), and a medicine inlet (38); multiple mounting bosses are distributed around the lid, and the lid is detachably and fixedly connected to the box body by bolts I and mounting bosses; a sealing groove is provided on the side of the lid opposite to the box body, and an annular gasket is provided in the sealing groove, which seals the contact surface between the lid and the box body; the bottom shape of the box body is complementary to the internal structure of the UAV body (1), so that the medicine box is embedded in the UAV body.

3. The multi-rotor agricultural drone based on a precision spraying device according to claim 1, characterized in that: The transmission mechanism includes a support plate (33), a transmission shaft (332), a gear ring (329), a sun gear (334), and multiple planet gears (324). The support plate is located inside the medicine box and is fixedly connected to the inside of the medicine box by bolt II (35); a circular opening is opened in the middle of the support plate, the opening penetrates the support plate, the gear ring is located in the opening and is fixedly connected to the opening, and the center line of the gear ring coincides with the axis of the transmission shaft. A motor mounting base (322) is provided above the support plate. The motor mounting base is fixedly connected to the support plate, and the geared motor is fixedly connected to the motor mounting base. One end of the lead screw is connected to the drive end of the geared motor via a transmission shaft (332), and the geared motor can drive the lead screw to rotate around its axis via the transmission shaft. The sun gear is sleeved on the outside of the drive shaft and fixedly connected to the drive shaft, and the axis of the sun gear coincides with the axis of the drive shaft, so that the sun gear can rotate around the axis of the drive shaft; the sun gear and planet gear are both located inside the gear ring, and the sun gear, planet gear and the inner side of the gear ring are meshed and connected; a planet carrier (323) is also provided above the support plate, the planet carrier is sleeved on the outside of the drive shaft and rotatably connected to the drive shaft; the upper side of the planet gear is rotatably connected to the planet carrier; When the geared motor drives the transmission shaft to rotate around the axis of the transmission shaft, the transmission shaft can drive the planetary gears to rotate inside the gear ring through the sun gear; wherein, the sun gear rotates around the axis of the transmission shaft inside the gear ring, and the planetary gears can rotate around the axis of the planetary gears while moving circumferentially around the gear ring; the top of the agitator and the top of the scraper are fixedly connected to the lower side of the planetary gears respectively, so that the agitator and the scraper can move with the planetary gears.

4. The multi-rotor crop-spraying unmanned aerial vehicle based on the precise application device according to claim 3, characterized in that: The transmission ratio between the sun gear and the planet gears is greater than 1.

5. The multi-rotor crop-spraying unmanned aerial vehicle based on the precise drug delivery device according to claim 1, characterized in that: Multiple fixing rods are provided below the movable plate (330). The upper end of the fixing rod is fixedly connected to the movable plate, and the lower end of the fixing rod is connected to the float plate (3301) through a spherical joint.

6. The multi-rotor crop-spraying unmanned aerial vehicle based on the precise application device according to claim 5, characterized in that: Multiple guide holes I are provided on the float plate (3301) so that the medicine liquid in the medicine tank (3) can flow through the guide holes I.

7. The multi-rotor crop-spraying unmanned aerial vehicle based on the precise drug delivery device according to claim 3, characterized in that: The wall scraper (326) includes a connecting rod I, the upper end of which passes through the movable plate and is fixedly connected to the lower side of the planetary gear; the lower end of the connecting rod I is provided with a plurality of spiral stirring blades I (3261), the upper end of the stirring blades I is fixedly connected to the connecting rod I, and the lower end of the stirring blades I is provided with an elastic scraper (3262), and the elastic scraper is in flexible contact with the inner wall of the bottom of the medicine box (3).

8. The multi-rotor crop-spraying unmanned aerial vehicle based on the precise application device according to claim 3, characterized in that: The stirrer (328) includes a connecting rod II, the upper end of which passes through the movable plate and is fixedly connected to the lower side of the planetary gear; the lower end of the connecting rod II is provided with a plurality of stirring blades II (3281), the stirring blades II are spaced apart along the length of the connecting rod II, and one end of the stirring blade II is fixedly connected to the connecting rod II, and the other end extends into the medicine tank; the stirring blades II (3281) are provided with a plurality of guide holes II, so that the medicine liquid in the medicine tank (3) can flow through the guide holes II.

9. The multi-rotor agricultural drone based on a precision spraying device according to claim 1, characterized in that: The spraying device (5) includes multiple mounting bases (506), a linear module (507), a rotating mechanism (501), a swinging mechanism (504), a follow-up blade (502), a nozzle (503), and a monitoring module (505); The linear module is located below the arm (2), and its length direction is consistent with the length direction of the arm. It is fixedly connected to the arm through multiple mounting seats. The linear module includes a drive mechanism I, the drive end of which is fixedly connected to the rotating mechanism. The drive mechanism I can drive the rotating mechanism to slide along the length direction of the arm. The rotating mechanism includes a drive mechanism II, which enables the rotating end of the rotating mechanism to rotate around the axis of the rotating end. The rotating end of the rotating mechanism is fixedly connected to the swing mechanism, and the rotating mechanism enables the swing mechanism to rotate around the axis of the rotating end. The swing mechanism includes a drive mechanism III. The swing end of the swing mechanism is rotatably connected to the swing mechanism via a rotating shaft. The drive mechanism III can drive the swing end of the swing mechanism to swing around the axis of the rotating shaft. The follower blade is located between the nozzle and the swing mechanism, and the follower blade can rotate around the center line of the nozzle under the drive of the drive mechanism IV, so as to provide the nozzle with an air field consistent with its spraying direction. The medicine tank is connected to the nozzle via a medicine delivery pipe; The monitoring module includes multiple distance sensors and angle sensors. The distance sensors monitor the moving distance of the nozzle (503), and the angle sensors monitor the rotation angle of the rotating end of the rotating mechanism (501) and the swing angle of the swing end of the swing mechanism (504).

Images