Bionic agricultural pesticide spraying aircraft and control method thereof

Abstract

The invention belongs to the technical field of agricultural unmanned aerial vehicles, and particularly relates to a bionic agricultural pesticide spraying aircraft and a control method thereof. The aircraft comprises a fuselage and n supporting legs evenly distributed around the fuselage, n is an even number larger than or equal to 4, and each supporting leg is provided with a set of propellers driven by a motor. A plurality of independent pesticide bins are arranged in the machine body, an outlet of each pesticide bin is connected with a mixing box in the machine body through a water path, a metering pump is connected into the water path, a stirring device is arranged in the mixing box, a plurality of nozzles are evenly distributed on the periphery of the machine body, an outlet pipeline of the mixing box is divided into branches with the same number as the nozzles, and the branches are connected with the nozzles in a one-to-one mode. A booster pump is mounted on the branch; depth cameras are distributed outside the fuselage and used for acquiring environment images, and the aircraft controls a flight path according to the environment images; the unmanned aerial vehicle adopts a partitioned pesticide bin and octopus bionic eight-rotor design, and has high pesticide mixing capacity and stable flight control performance.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural unmanned aerial vehicles, and in particular relates to a bionic agricultural spraying aircraft and a control method thereof. Background Art

[0002] Agricultural drones have positive significance for the healthy development of agriculture. They are efficient, safe and precise agricultural machinery, which frees agricultural workers from heavy and dangerous operations and improves their working experience. On the other hand, most pesticides used in spraying will actually enter the soil, which will have a negative impact on the soil, water sources and organisms. Low-volume spraying methods represented by agricultural drones can achieve a pesticide utilization rate of 60%, thus reducing the use of pesticides.

[0003] However, existing agricultural plant protection drones have the following technical defects:

[0004] 1. Limited types of pesticides: Currently, drones on the market can only spray one type of pesticide at a time, but crop pests and diseases are often not limited to one type of pesticide, so they cannot meet all needs;

[0005] 2. Fixed pesticide concentration: The concentration of pesticides needs to be adjusted according to different crops and pests and diseases, but currently drones can only spray pesticides of fixed concentrations during operation;

[0006] 3. Insufficient sowing accuracy: Overseeding and missed sowing often occur, resulting in uneven crop growth and increased management costs in the later stages;

[0007] 4. Insufficient intelligence: It lacks functions such as high-precision positioning and intelligent route planning, and is difficult to adapt to complex terrain and operating environments.

[0008] These problems seriously restrict the application effect and promotion scope of agricultural drones. Therefore, developing a multifunctional agricultural plant protection drone that can solve the above problems has important practical significance and application value. Summary of the invention

[0009] The present invention aims to solve the problem that the existing agricultural plant protection UAV cannot automatically adjust the spray type and drug concentration, and the UAV has the phenomenon of replay and missed spraying, and the intelligence level is insufficient.

[0010] The present invention provides the following technical solution: a bionic agricultural spraying aircraft, comprising a fuselage and n legs evenly distributed around the fuselage, n being an even number ≥ 4, and each leg being equipped with a set of propellers driven by a motor;

[0011] There are several independent medicine bins arranged inside the fuselage. The outlet of each medicine bin is connected to a mixing box inside the fuselage through a waterway. A metering pump is connected in the waterway. A stirring device is arranged inside the mixing box. There are several spray nozzles evenly distributed around the fuselage outside the fuselage. The outlet pipeline of the mixing box is divided into branches equal in number to the number of spray nozzles, and the branches are connected to the spray nozzles one by one. A booster pump is installed on the branch.

[0012] A depth camera is distributed outside the fuselage. The depth camera is used to obtain environmental images, and the aircraft controls the flight path according to the environmental images.

[0013] Furthermore, several medicine bins are evenly distributed around the longitudinal axis of the fuselage.

[0014] Furthermore, the fuselage includes a base at the lower part and a housing at the upper part. The legs are connected to the base. The motor and the propeller are installed at the ends of the legs. The legs bend upward so that the propeller is above the center of gravity of the fuselage. The medicine bins are located inside the housing, and the spray nozzles are located on the housing.

[0015] Furthermore, the mixing box is located below the medicine bins.

[0016] Furthermore, the housing is spherical.

[0017] Furthermore, the legs are fixed to the base by bolts.

[0018] Furthermore, feet are arranged at the bottom of the base.

[0019] Furthermore, 8 legs are connected to the fuselage, and the spray nozzles are located between two legs.

[0020] An aircraft control method for controlling the aforementioned bionic agricultural spraying aircraft includes:

[0021] S1: The aircraft receives point-to-point position data from the upper computer.

[0022] S2: The depth camera generates high-precision three-dimensional point cloud data in real time by running the FAST-LIO2 algorithm, and preprocesses the three-dimensional point cloud data obtained by the depth camera to remove abnormal data points.

[0023] S3: Based on the object detection algorithm of deep learning, identify and extract the farmland features in the three-dimensional point cloud data, construct a local map of the farmland environment through the farmland features, and match it with the global map to accurately locate the current position of the aircraft and the position of the target point.

[0024] S4: Use the Dijkstra algorithm to plan a flight path.

[0025] S5: During the flight of the aircraft along the planned path, continuously use the IMU and GPS in the aircraft to fuse the positioning data in real time to monitor and adjust the position and attitude of the aircraft in real time.

[0026] Furthermore, data interaction between the aircraft and the host computer is carried out through a 5G communication module;

[0027] The 5G module of the aircraft encapsulates the 3D point cloud data collected by the depth camera after preprocessing into a 5G protocol data frame and uploads it to the 5G module of the host computer;

[0028] The 5G module of the host computer receives, unpacks, verifies and publishes it to the corresponding topic of the ROS2 system; the ROS2 system relies on the shared topic mechanism to receive and process data, and the calculation module accordingly conducts point-to-point function calculation and path planning in real time, and then encapsulates the result into an instruction frame and feeds it back to the aircraft, and the aircraft executes operations according to the instructions.

[0029] Compared with the prior art, the advantages of the present invention are as follows:

[0030] A bionic agricultural spraying aircraft provided by the present invention adopts an eight-propeller layout, arranges eight propellers at the tops of 8 support legs, simulates the movement mode of an octopus, and provides efficient flight power and stable attitude control. This design allows the aircraft to fly stably in complex terrains and can accurately control the flight path. The multi-rotor design also improves the load capacity of the aircraft, ensuring strong power margin while carrying pesticides and water.

[0031] Three independent medicine bins are designed at the top of the aircraft for storing different types of pesticides. Each medicine bin is connected to a water pump, and the liquid medicine or water is transported to the mixing tank through the water pump to achieve rapid mixing. A stirring device is built into the mixing tank to ensure uniform mixing of the liquid medicine. The rotation speed of the water pump is adjustable, so as to control the mixing ratio and spraying speed, and ensure accurate pesticide application according to different operation requirements.

[0032] The aircraft control system adopts embedded flight control technology and combines multi-sensor data (GPS, inertial measurement unit) to achieve precise flight attitude control and path planning. Description of the Drawings

[0033] Figure 1 is a perspective view of the bionic agricultural spraying aircraft;

[0034] Figure 2 is an exploded view of the bionic agricultural spraying aircraft;

[0035] Figure 3 is a sectional view of the housing;

[0036] Figure 4 is a schematic diagram of the support leg.

[0037] In the figure: 1 - fuselage; 1.1 - base; 1.2 - casing; 1.3 - support leg; 2 - leg; 3 - nozzle; 4 - motor; 5 - propeller; 6 - medicine bin; 7 - mixing tank; 8 - stirring device. Detailed implementation mode

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Embodiment 1

[0040] As Figures 1 to 4 shown: A bionic agricultural spraying aircraft includes a fuselage 1 and n legs 2 evenly distributed around the fuselage 1 in a circle. n is an even number greater than or equal to 4. A set of propellers 5 driven by a motor 4 are installed on each leg 2; several independent medicine bins 6 are arranged inside the fuselage 1. Different liquid medicines are stored in different medicine bins 6. The outlet of each medicine bin 6 is connected to the mixing tank 7 inside the fuselage 1 through a waterway. A metering pump is connected in the waterway. The liquid medicine in the medicine bin 6 is quantitatively pumped into the mixing tank 7 through the metering pump to achieve the ratio of different liquid medicine portions. A stirring device 8 is arranged in the mixing tank 7 to mix the liquid medicine in the mixing tank 7 evenly. If it is necessary to adjust the concentration of the liquid medicine, water is stored in one of the medicine bins in advance, and the water is mixed with the liquid medicine in the mixing tank 7 to change the concentration of the liquid medicine. Several nozzles 3 are evenly distributed around the fuselage 1 outside the fuselage 1. The outlet pipeline of the mixing tank 7 is divided into branches equal to the number of nozzles 3, and the branches are connected to the nozzles 3 one by one. A booster pump is installed on the branch; the booster pump pressurizes the liquid medicine and pumps it to the nozzle 3. The opening and closing of each nozzle 3 can be independently controlled by the booster pump.

[0041] A depth camera is distributed outside the fuselage 1. The depth camera is used to obtain environmental images, and the aircraft controls the flight path according to the environmental images.

[0042] Several medicine bins 6 are evenly distributed around the longitudinal axis of the fuselage 1.

[0043] The fuselage 1 includes a base 1.1 at the lower part and a casing 1.2 at the upper part. The legs 2 are connected to the base 1.1. The motor 4 and the propeller 5 are installed at the ends of the legs 2. The legs 2 bend upward until the propeller 5 is above the center of gravity of the fuselage 1. The casing 1.2 is spherical, and the aircraft presents the shape of an octopus; the medicine bin 6 is located inside the casing 1.2, and the nozzle 3 is located on the casing 1.2.

[0044] The mixing tank 7 is located below the medicine bin 6, and the liquid medicine in the medicine bin 6 flows naturally into the mixing tank 7 to prevent the liquid medicine from remaining in the medicine bin 6.

[0045] Eight legs 2 are connected to the fuselage 1, and the nozzle 3 is located between two legs 2. A plurality of evenly distributed nozzles 3 are designed to adapt to the layout of the octocopter, maximizing the spraying coverage. The nozzle 3 is supplied with liquid by an independent booster pump, and the booster pump can respond to the commands of the upper computer to control the start and stop of spraying in real time, ensuring that pesticides are not wasted when switching operation areas.

[0046] The legs 2 are fixed to the base 1.1 by bolts, and the legs 2 and the base 1.1 are connected by a detachable structure, which facilitates the removal of the legs 2 during transportation and reduces the overall volume of the machine. The bottom of the base 1.1 is provided with feet 1.3. The propellers 5 are made of carbon fiber materials, providing sufficient strength and rigidity while maintaining light weight.

[0047] Eight depth cameras are evenly distributed around the fuselage 1. The eight depth cameras generate high-precision three-dimensional point cloud data in real time by running the FAST-LIO2 algorithm. Combining the strong coupling effect of the IMU (spatial attitude sensor) and GPS, making full use of the approximate position information provided by the Global Positioning System (GPS), as well as information such as acceleration and angular velocity measured by the Inertial Measurement Unit (IMU), to achieve deep data fusion with the depth camera.

[0048] This fusion method can provide a more accurate positioning basis for the aircraft in a complex farmland environment, effectively making up for the limitations of a single sensor in different scenarios.

[0049] Embodiment 2

[0050] A control method for a bionic agricultural spraying aircraft in Embodiment 1 is as follows:

[0051] Perform point-to-point operations on the upper computer with the aim of inputting the task of spraying farmland at fixed points. First, preprocess the three-dimensional point cloud data obtained by the depth camera to remove abnormal data points caused by factors such as sensor noise and environmental interference. Subsequently, based on the object detection algorithm of deep learning, identify and extract the farmland features in the three-dimensional point cloud data. The farmland features include landmark features such as ridges and crop boundaries. Construct a local map of the farmland environment through these farmland features and match it with the global map to accurately locate the current position of the aircraft and the position of the target point.

[0052] Then, based on the current position of the aircraft and the position of the target point, considering the actual situations such as the terrain undulation of the farmland and the density of crop distribution, use the Dijkstra algorithm to plan a safe and efficient flight path, which can not only avoid collisions with obstacles in the farmland but also meet the requirements of coverage rate and uniformity of plant protection operations to the greatest extent.

[0053] During the flight of the aircraft along the planned path, the IMU and GPS are continuously used to fuse the real-time positioning data to monitor and adjust the position and attitude of the aircraft in real time. Once it is found that the aircraft deviates from the preset path, through the feedback control mechanism, the flight parameters of the aircraft are automatically adjusted to ensure that it accurately flies along the point-to-point planned path and efficiently completes the farmland plant protection operation task.

[0054] Rely on the 5G communication module to realize data interaction between the aircraft and the upper computer. The aircraft integrates 5G functions, encapsulates the data collected by the depth camera after preprocessing (removing noise and data compression) into 5G protocol data frames and uploads them. The 5G network builds a reliable link with the characteristics of high speed, low latency and large capacity. After receiving, the upper computer 5G module unpacks, verifies and publishes the data to the corresponding topics of the ROS2 system. The ROS2 system relies on the shared topic mechanism to receive and process the data. The calculation module accordingly conducts real-time point-to-point function calculations, such as path planning, etc., and then encapsulates the results into instruction frames and feeds them back to the aircraft. The aircraft executes operations according to the instructions. At the same time, through the ROS2 shared topic design, topics such as ` / point_cloud_data` are defined to transmit different types of data, the message types of each topic are clarified, and the publishing and subscribing behaviors of the ROS2 nodes at the aircraft and upper computer ends are standardized.

[0055] To ensure the efficient, stable and safe data transmission, a series of measures are taken. In terms of 5G communication optimization, QoS parameters are set according to the data characteristics. The flight instructions have high priority and low latency, and the point cloud data has lower priority and high throughput; a point cloud data compression algorithm such as wavelet transform is used to reduce the transmission volume; the transmission rate and modulation method are dynamically adjusted according to the 5G network conditions. In terms of security design, a symmetric encryption algorithm (such as AES) is used to encrypt the transmitted data; identity authentication is carried out by means of a pre-shared key when establishing a connection between the upper computer and the aircraft; different user permissions are set on the upper computer to implement access control over instruction sending and data viewing to prevent data leakage and unauthorized operations.

[0056] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bionic agricultural spraying aircraft, comprising a fuselage (1) and n legs (2) evenly distributed around the fuselage (1) in a circle, where n is an even number greater than or equal to 4, and a set of propellers (5) driven by motors (4) are installed on each leg (2); It is characterized in that: Several independent medicine bins (6) are arranged inside the fuselage (1). The outlet of each medicine bin (6) is connected to a mixing tank (7) inside the fuselage (1) through a waterway. A metering pump is connected in the waterway. A stirring device (8) is arranged inside the mixing tank (7). Several spray nozzles (3) are evenly distributed around the fuselage (1) outside the fuselage (1). The outlet pipeline of the mixing tank (7) is divided into branches equal in number to the spray nozzles (3), and the branches are connected to the spray nozzles (3) one by one. A booster pump is installed on the branch; A depth camera is distributed outside the fuselage (1), and the depth camera is used to obtain environmental images, and the aircraft controls the flight path according to the environmental images.

2. The bionic agricultural spraying aircraft according to claim 1, wherein: Several of the medicine bins (6) are evenly distributed around the longitudinal axis of the fuselage (1).

3. The bionic agricultural spraying aircraft according to claim 1, wherein: The fuselage (1) includes a lower base (1.1) and an upper housing (1.2). The legs (2) are connected to the base (1.1). The motors (4) and the propellers (5) are installed at the ends of the legs (2). The legs (2) bend upward so that the propellers (5) are above the center of gravity of the fuselage (1); the medicine bins (6) are located inside the housing (1.2), and the spray nozzles (3) are located on the housing (1.2).

4. The bionic agricultural spraying aircraft according to claim 2, wherein: The mixing tank (7) is located below the medicine bin (6).

5. The bionic agricultural spraying aircraft according to claim 3, characterized in that: The housing (1.2) is spherical.

6. The bionic agricultural spraying aircraft according to claim 3, wherein: The legs (2) are fixed to the base (1.1) by bolts.

7. The bionic agricultural spraying aircraft according to claim 6, characterized in that: The bottom of the base (1.1) is provided with feet (1.3).

8. The bionic agricultural pesticide spraying aircraft according to claim 1, characterized in that: 8 legs (2) are connected to the fuselage (1), and the spray nozzles (3) are located between two legs (2).

9. A flight vehicle control method for controlling the bionic agricultural spraying flight vehicle according to any one of claims 1 to 8, characterized in that, Including: S1: The aircraft receives point-to-point position data from the upper computer; S2: The depth camera generates high-precision three-dimensional point cloud data in real time by running the FAST-LIO2 algorithm, and preprocesses the three-dimensional point cloud data obtained by the depth camera to remove abnormal data points; S3: Based on the object detection algorithm of deep learning, identify and extract the farmland features in the three-dimensional point cloud data, construct a local map of the farmland environment through the farmland features, and match it with the global map to accurately locate the current position of the aircraft and the position of the target point; S4: Use the Dijkstra algorithm to plan a flight path; S5: During the flight of the aircraft along the planned path, continuously use the IMU and GPS in the aircraft to fuse and position the data in real time, and monitor and adjust the position and attitude of the aircraft in real time.

10. A flight vehicle control method according to claim 9, characterized in that: Data interaction between the aircraft and the upper computer is carried out through a 5G communication module; The 5G module of the aircraft encapsulates the three-dimensional point cloud data collected by the depth camera after preprocessing into a 5G protocol data frame and uploads it to the 5G module of the upper computer; The 5G module of the upper computer receives, unpacks, verifies and publishes it to the corresponding topic of the ROS2 system; the ROS2 system relies on the shared topic mechanism to receive and process data, and the calculation module accordingly carries out point-to-point function calculation in real time, plans the path, and then encapsulates the result into an instruction frame and feeds it back to the aircraft, and the aircraft executes the operation according to the instruction.

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