Orchard fertilization method and device based on water drip detection

Abstract

The invention provides an orchard fertilization method and device based on water drip detection, and relates to the technical field of agricultural and forestry machinery, the method comprises the following steps: collecting position data and driving azimuth data of a fertilizer applicator in the driving process of an orchard; collecting two-dimensional point cloud data of the target fruit tree through a two-dimensional laser radar; based on the timestamp of the two-dimensional point cloud data, fusing the position data, the driving azimuth data and the two-dimensional point cloud data to obtain fused point cloud data; performing three-dimensional reconstruction on the target fruit tree based on the fused point cloud data to obtain target point cloud data; generating a water drip navigation path of the target fruit tree based on the target point cloud data; and controlling the fertilizer applicator to perform ditching and / or fertilizer application according to the water drip navigation path. According to the orchard fertilization method and device based on water drip detection provided by the invention, automatic fertilization operation along the water drip is realized, and the efficiency and precision of orchard fertilization operation are improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural and forestry machinery technology, and in particular to an orchard fertilization method and device based on drip line detection. Background Technology

[0002] In orchard fertilization, trenching along the edge of the tree canopy projected vertically to the ground (i.e., the drip line) not only ensures efficient fertilizer utilization but also helps prune the root system, thereby promoting tree growth and improving fruit quality.

[0003] However, the current level of automation in orchard fertilization operations is low. Fertilization methods mainly rely on semi-mechanized machines with limited functions and manual operation, making it difficult to achieve integrated and efficient operations of trenching, fertilization, and soil covering. This generally results in low efficiency and high labor intensity. In addition, the inability to accurately locate the drip line of the tree canopy leads to low fertilization precision. Summary of the Invention

[0004] This invention provides a method and apparatus for orchard fertilization based on drip line detection, which solves the technical problems of low fertilization efficiency and accuracy in existing orchard fertilization operations.

[0005] This invention provides an orchard fertilization method based on drip line detection, comprising the following steps: Collect location and azimuth data of the fertilizer applicator during its operation in the orchard; Two-dimensional point cloud data of the target fruit trees are collected by a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; Based on the timestamp of the two-dimensional point cloud data, the location data, the driving azimuth angle data, and the two-dimensional point cloud data are fused to obtain fused point cloud data; Based on the fused point cloud data, the target fruit tree is reconstructed in three dimensions to obtain the target point cloud data; Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated; The fertilizer applicator is controlled to perform trenching and / or fertilization according to the drip line navigation path.

[0006] According to the present invention, an orchard fertilization method based on drip line detection is provided, wherein the method involves fusing the location data, the driving azimuth angle data, and the two-dimensional point cloud data based on the timestamp of the two-dimensional point cloud data to obtain fused point cloud data, including: The location data is converted from the world coordinate system to the local coordinate system of the orchard to obtain local coordinate data; Using the timestamp as a time axis, the driving azimuth angle data is matched to the two-dimensional point cloud data according to the time axis by the nearest neighbor matching algorithm to obtain three-dimensional point cloud data; The fused point cloud data is obtained by fusing the local coordinate data and the 3D point cloud data along the time axis using a piecewise linear interpolation algorithm.

[0007] According to the present invention, an orchard fertilization method based on drip line detection is provided, wherein the step of performing three-dimensional reconstruction of the target fruit tree based on the fused point cloud data to obtain target point cloud data includes: Statistical filtering is performed on the fused point cloud data to obtain filtered point cloud data; The filtered point cloud data is rotated to obtain standard point cloud data; The target fruit tree is reconstructed in three dimensions based on the standard point cloud data to obtain the target point cloud data.

[0008] According to the present invention, a method for orchard fertilization based on drip line detection is provided, wherein the step of rotating the filtered point cloud data to obtain standard point cloud data includes: The slope of the fertilizer applicator's travel path is obtained by curve fitting; the travel path is determined based on the local coordinate data. Based on the slope, calculate the angle between the driving path and the straight line; The filtered point cloud data is rotated based on the included angle to obtain the standard point cloud data.

[0009] According to the present invention, an orchard fertilization method based on drip line detection is provided, wherein generating a drip line navigation path for the target fruit tree based on the target point cloud data includes: Based on the target point cloud data, extract the set of tree crown outline edge points of the target fruit tree; The drip line boundary of the target fruit tree is generated by performing concave hull fitting on the set of edge points of the tree crown outline. The discrete concave vertices in the drip line boundary are smoothed to generate the drip line navigation path.

[0010] According to the present invention, an orchard fertilization method based on drip line detection is provided, wherein extracting the set of tree crown contour edge points of the target fruit tree based on the target point cloud data includes: Principal component analysis is performed on the target point cloud data to extract the point cloud normal vectors; Based on the point cloud normal vectors, extract the point cloud abrupt change features; Based on the point cloud mutation features, the set of tree crown contour edge points is determined.

[0011] The present invention also provides an orchard fertilization device based on drip line detection, comprising the following modules: The first data acquisition module is used to collect the position data and azimuth angle data of the fertilizer applicator during its operation in the orchard. The second acquisition module is used to acquire two-dimensional point cloud data of the target fruit trees using a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; The point cloud fusion module is used to fuse the location data, the driving azimuth angle data and the two-dimensional point cloud data based on the timestamp of the two-dimensional point cloud data to obtain fused point cloud data. The 3D reconstruction module is used to perform 3D reconstruction of the target fruit tree based on the fused point cloud data to obtain the target point cloud data. The generation module is used to generate the drip line navigation path of the target fruit tree based on the target point cloud data; The control module is used to control the fertilizer applicator to perform trenching and / or fertilization according to the drip line navigation path.

[0012] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the orchard fertilization method based on drip line detection as described above.

[0013] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the orchard fertilization method based on drip line detection as described above.

[0014] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the orchard fertilization method based on drip line detection as described above.

[0015] The orchard fertilization method and device based on drip line detection provided by this invention collects the position data and azimuth angle data of the fertilizer applicator during its movement in the orchard, providing an accurate vehicle pose reference for subsequent data fusion and ensuring overall spatial consistency. It also collects two-dimensional point cloud data of the target fruit trees using a two-dimensional lidar mounted on the fertilizer applicator. The target fruit trees are those on either side of the fertilizer applicator's location. The lidar scans the fruit tree surface to obtain detailed geometric point cloud information, providing the raw data foundation for three-dimensional reconstruction and achieving non-contact canopy morphology acquisition. Based on the timestamps of the two-dimensional point cloud data, it further analyzes the position data, azimuth angle data, and two-dimensional point cloud data. Cloud data is fused to obtain fused point cloud data, which is then aligned with timestamps to eliminate spatiotemporal errors between sensor data, generating fused point cloud data that improves the accuracy and reliability of subsequent 3D reconstruction. Based on the fused point cloud data, the target fruit tree is reconstructed in 3D to obtain target point cloud data, thereby accurately reconstructing the 3D structure of the target fruit tree. Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated, ensuring that the fertilization location accurately corresponds to the dense root zone of the target fruit tree. The fertilizer applicator is controlled to dig trenches and / or fertilize according to the drip line navigation path, thereby realizing automated fertilization operation along the drip line without manual intervention, improving the fertilization efficiency and accuracy in orchard fertilization operations. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of the orchard fertilization method based on drip line detection provided by the present invention.

[0018] Figure 2 This is one of the overall structural schematic diagrams of the fertilizer applicator provided by the present invention.

[0019] Figure 3 This is a schematic diagram of the hardware structure of the fertilizer applicator detection system provided by the present invention.

[0020] Figure 4 This is the second schematic diagram of the overall structure of the fertilizer applicator provided by the present invention.

[0021] Figure 5 This is a schematic diagram of point cloud coordinate system calibration provided by the present invention.

[0022] Figure 6 This is a schematic diagram of point cloud reconstruction provided by the present invention.

[0023] Figure 7 This is a schematic diagram of the drip line extraction process provided by the present invention.

[0024] Figure 8 This is a schematic diagram of the orchard fertilization device based on drip line detection provided by the present invention.

[0025] Figure 9 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] The following is combined Figures 1 to 9 This invention describes an orchard fertilization method and apparatus based on drip line detection.

[0028] Figure 1 This is a flowchart illustrating the orchard fertilization method based on drip line detection provided by the present invention, as shown below. Figure 1 As shown, the method includes the following steps: Step 101: Collect the position data and azimuth angle data of the fertilizer applicator during its operation in the orchard; Step 102: Collect two-dimensional point cloud data of the target fruit trees using a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; Specifically, while the fertilizer applicator is moving through the orchard, it simultaneously collects location data, azimuth data, and two-dimensional point cloud data of the fruit trees on both sides of the fertilizer applicator's location.

[0029] Figure 2 This is one of the overall structural schematic diagrams of the fertilizer applicator provided by the present invention, such as... Figure 2 As shown in the embodiments of the present invention, the fertilizer applicator includes at least five parts: a data acquisition device, a tracked chassis, a fertilizer applicator, a ditching device, and a control system.

[0030] The data acquisition device mainly consists of a two-dimensional lidar, a real-time kinematic global navigation satellite system (RTK-GNSS), a nine-axis electronic compass, and an industrial panel PC.

[0031] Figure 3 This is a schematic diagram of the hardware structure of the fertilizer applicator detection system provided by the present invention, as shown below. Figure 3 As shown, the RTK-GNSS communicates with the industrial panel PC via a Universal Synchronous / Asynchronous Receiver / Transmitter (USART); the nine-axis electronic compass communicates with the industrial panel PC via USART; and the 2D LiDAR communicates with the industrial panel PC via a network port. A battery is connected to the 2D LiDAR via a wire to provide power to the LiDAR.

[0032] RTK-GNSS is used to collect real-time location data of the fertilizer applicator during its movement in the orchard, specifically including the longitude, latitude, and elevation information of the fertilizer applicator during its movement in the orchard; a nine-axis electronic compass is used to collect real-time azimuth data of the fertilizer applicator during its movement in the orchard; a two-dimensional lidar is used to collect two-dimensional point cloud data of the target fruit trees; and an industrial panel PC is used to receive and process the location data, azimuth data, and two-dimensional point cloud data.

[0033] A tracked chassis includes at least a frame, drive wheels, tracks, track rollers, track tensioning devices and guide wheels, carrier rollers, and suspension components that connect the track rollers and the machine body, which are used to support the weight of the fertilizer applicator.

[0034] The fertilization device includes at least components such as a fertilizer bin, an auger device, a fertilizer baffle, a conveyor belt, and a drive motor. Figure 4 This is the second schematic diagram of the overall structure of the fertilizer applicator provided by the present invention, as shown below. Figure 4 As shown, a nine-axis electronic compass is installed in the head area of ​​the fertilizer applicator, and an auger device is installed in the fertilizer bin. The bottom of the fertilizer bin is fixed to the frame and is used to store fertilizer; the auger device in the fertilizer bin is used to push the fertilizer outward, and the fertilizer is conveyed onto the conveyor belt. Powered by a drive motor, the conveyor belt is rotated, thereby conveying the fertilizer to the ground.

[0035] The trenching device includes at least a drive motor, trenching cutter head, hydraulic cylinders, contour wheels, a parallel four-bar linkage, a traction platform, and a soil covering device. The device is used for trenching operations and mixing the trenched soil with fertilizer spread on the ground. During trenching, the tracked chassis is connected to the traction platform; the parallel four-bar linkage floats freely relative to the tracked chassis in the vertical direction; the movement of the contour wheels is directly transmitted to the parallel four-bar linkage via connecting rods, causing the soil covering device to follow the terrain contour; the drive motor drives the trenching cutter head to rotate, and the depth of the trenching cutter head can be adjusted via the hydraulic cylinders; the rotating soil covering device is attached to the cutter head, which not only completes the soil covering operation but also prevents fertilizer from splashing during soil mixing, avoiding fertilizer waste. The hydraulic oil in the hydraulic cylinders is regulated in terms of flow, pressure, and direction via an integrated block (or valve assembly) to ensure precise control of the hydraulic cylinders, thereby driving the mechanical operation.

[0036] A control system includes at least the following components: a data acquisition device, an electronic control unit (ECU), and a drive device.

[0037] The data acquisition device is used to output the coordinates of the drip line based on the acquired position data, driving azimuth angle data, and two-dimensional point cloud data.

[0038] The ECU is the controller of the entire control system, used to output different control commands to different actuators based on the drip line coordinates, so that they can complete the corresponding actions. The control commands include at least trenching commands, fertilization commands, and movement commands.

[0039] The drive unit mainly includes a drive motor and a hydraulic cylinder, which provide power to the actuators that execute trenching, fertilizing, and movement commands.

[0040] It should be noted that in actual use, the functions of the fertilizer applicator include opening trenches without applying fertilizer, applying fertilizer without opening trenches, and opening trenches and applying fertilizer simultaneously.

[0041] Based on the aforementioned fertilizer applicator, in one embodiment, the fertilizer applicator can first be controlled to travel in a straight line (or approximately a straight line) between rows in the orchard. A vehicle-mounted two-dimensional LiDAR scans the fruit trees on both sides of the row where the fertilizer applicator is located to obtain two-dimensional point cloud data of the fruit trees. Simultaneously, during the movement, RTK-GNSS collects the vehicle's position data in real time, and a nine-axis electronic compass collects and saves the vehicle's azimuth angle data in real time.

[0042] Step 103: Based on the timestamp of the two-dimensional point cloud data, fuse the location data, the driving azimuth angle data, and the two-dimensional point cloud data to obtain fused point cloud data; Further, the process of fusing the location data, the driving azimuth angle data, and the two-dimensional point cloud data based on the timestamp of the two-dimensional point cloud data to obtain fused point cloud data includes: The location data is converted from the world coordinate system to the local coordinate system of the orchard to obtain local coordinate data; Using the timestamp as a time axis, the driving azimuth angle data is matched to the two-dimensional point cloud data according to the time axis by the nearest neighbor matching algorithm to obtain three-dimensional point cloud data; The fused point cloud data is obtained by fusing the local coordinate data and the 3D point cloud data along the time axis using a piecewise linear interpolation algorithm.

[0043] Specifically, firstly, a world coordinate system and a corresponding local orchard coordinate system are established, and the transformation relationship between the world coordinate system and the local orchard coordinate system is determined based on the location data output by RTK-GNSS.

[0044] The world coordinate system refers to the World Geodetic System 1984 (WGS-84), which is specifically defined as follows: the origin of the coordinate system is the Earth's center of mass O; the Z-axis points to the Conventional Terrestrial Pole (CTP) defined by the Bureau International de l'Heure 1984.0 (BIH1984.0); the X-axis points to the intersection of the zero meridian plane defined by BIH1984.0 and the corresponding equator of the CTP; and the Y-axis rotates 90° eastward in the CTP equatorial plane to form a right-handed system.

[0045] The conversion relationship between WGS-84 spherical coordinates and WGS-84 rectangular coordinates is as follows: In the formula, Let WGS-84 rectangular coordinates be any point on the Earth's surface. These represent the latitude, longitude, and altitude of the point, respectively. N Let be the radius of curvature of the ellipsoid at that point, and e be the first aspect of the ellipsoid. e and R N The calculation expressions are as follows: In the formula, a and b are the semi-major axis length and semi-minor axis length of the reference ellipsoid, respectively.

[0046] The conversion relationship between WGS-84 rectangular coordinates and horizontal coordinates (i.e., the local coordinate system of the orchard) is as follows: In the formula, Let be the horizontal coordinates of any point in the orchard. The coordinates of this point are the WGS-84 rectangular coordinates. The coordinates of this point are the WGS-84 rectangular coordinates of the origin of the horizontal coordinate system. and This refers to the geographical latitude and longitude of the point. and The symbol is adjusted according to the hemisphere where the point is located.

[0047] Based on the above transformation relationship, the location data is transformed from the world coordinate system to the local coordinate system of the orchard to obtain local coordinate data.

[0048] Data from 2D LiDAR, RTK-GNSS, and a nine-axis electronic compass are fused using timestamps. Using the LiDAR timestamp as the time axis, nearest neighbor matching is applied to the driving azimuth data (for each LiDAR timestamp, the data point with the smallest absolute time difference is found in the driving azimuth data, and the matched driving azimuth data is directly assigned to the LiDAR timestamp). Let the LiDAR timestamp be... The timestamp set of driving azimuth angle data is The matching rule is: In the formula, Indicates the matching time. Any time in the set of timestamps for driving azimuth angle data.

[0049] Based on the matching time, the driving azimuth data is matched to the 2D point cloud data. After obtaining the 3D point cloud data, the local coordinate data and the 3D point cloud data are fused according to the time axis using a piecewise linear interpolation algorithm. The specific steps include: (1) Time interval division: The corresponding time points in the local coordinate data are used as nodes to form continuous time intervals. .

[0050] (2) Interval interpolation: For each lidar timestamp Perform linear interpolation: In the formula, This represents the fused point cloud data obtained after interpolation. For local coordinate data in The value at time; For local coordinate data in The value at time; This represents the time progress percentage (0~1).

[0051] (3) Boundary handling: Set the value of the first point before the first node. ; Set the value of the last node after the last node. An exact match will set the value of the corresponding node to... .

[0052] The embodiments of the present invention effectively reduce the fusion error caused by different sensor sampling frequencies by using synchronization algorithms tailored to different data characteristics, thereby improving the accuracy and reliability of data fusion; by using a local coordinate system in the orchard, complex calculations in the global geodetic coordinate system are avoided, improving data processing speed and thus improving the real-time performance of fertilization operations.

[0053] Step 104: Perform three-dimensional reconstruction of the target fruit tree based on the fused point cloud data to obtain target point cloud data; Further, the step of performing three-dimensional reconstruction of the target fruit tree based on the fused point cloud data to obtain target point cloud data includes: Statistical filtering is performed on the fused point cloud data to obtain filtered point cloud data; The filtered point cloud data is rotated to obtain standard point cloud data; The target fruit tree is reconstructed in three dimensions based on the standard point cloud data to obtain the target point cloud data.

[0054] Specifically, in one embodiment, after obtaining the fused point cloud data, it can first be ensured that each frame of lidar data (i.e., two-dimensional point cloud data) in the fused point cloud data is strictly aligned with the driving azimuth angle data and local coordinate data at the corresponding time. Then, the installation angle deviation of the sensors (including two-dimensional lidar, RTK-GNSS and nine-axis electronic compass) is corrected, a fixed compensation value is set, accurate motion compensation is achieved, and data accuracy is improved.

[0055] After motion compensation, a statistical filtering algorithm is used to remove outliers from the fused point cloud data (e.g., neighborhood points ≥ 30, standard deviation threshold ≤ 1.5) to obtain filtered point cloud data.

[0056] Further, the step of rotating the filtered point cloud data to obtain standard point cloud data includes: The slope of the fertilizer applicator's travel path is obtained by curve fitting; the travel path is determined based on the local coordinate data. Based on the slope, calculate the angle between the driving path and the straight line; The filtered point cloud data is rotated based on the included angle to obtain the standard point cloud data.

[0057] Specifically, although the fertilizer applicator can be controlled to travel in a straight line (or approximately a straight line) between rows in the orchard when collecting data, the actual travel path of the fertilizer applicator is not an ideal straight path. Therefore, in this embodiment of the invention, the least squares method is used to fit the travel path in order to obtain the slope of the vehicle's travel path.

[0058] For example, in one embodiment, suppose there is a set of data points ( The goal of the least squares method is to find the best-fitting line $y=kx$ (a line passing through the origin). The expression is as follows: In the formula, S is the sum of squared residuals, n is the number of data points, and k is the slope parameter to be determined.

[0059] The optimal solution can be obtained by taking the derivative of S and setting the derivative to zero: The final slope k is: Based on this slope, the angle θ formed by it and the line y=0 is further calculated. By rotating the overall fruit tree point cloud data by 90°+θ, the baseline of the point cloud is determined, and standard point cloud data is obtained. Figure 5 This is a schematic diagram of point cloud coordinate system calibration provided by the present invention, as shown below. Figure 5 As shown.

[0060] After obtaining standard point cloud data, the target fruit tree is reconstructed in three dimensions based on the standard point cloud data to obtain target point cloud data. Figure 6 This is a schematic diagram of point cloud reconstruction provided by the present invention, such as... Figure 6 As shown, accurate three-dimensional reconstruction of fruit trees was achieved by collecting data from three sensors (i.e., two-dimensional lidar, RTK-GNSS, and nine-axis electronic compass).

[0061] This invention effectively removes environmental interference and sensor noise from fused point cloud data through statistical filtering algorithms, avoiding misleading results from noise in subsequent edge extraction. It also corrects vehicle heading deviation through coordinate rotation, achieving high-precision and automated correction of point cloud orientation. This ensures that the subsequently extracted drip line is the true vertical projection of the tree canopy relative to the ground, improving the accuracy of the subsequent drip line navigation path.

[0062] Step 105: Based on the target point cloud data, generate the drip line navigation path for the target fruit tree; Further, generating the drip line navigation path for the target fruit tree based on the target point cloud data includes: Based on the target point cloud data, extract the set of tree crown outline edge points of the target fruit tree; The drip line boundary of the target fruit tree is generated by performing concave hull fitting on the set of edge points of the tree crown outline. The discrete concave vertices in the drip line boundary are smoothed to generate the drip line navigation path.

[0063] Further, the step of extracting the set of tree crown outline edge points of the target fruit tree based on the target point cloud data includes: Principal component analysis is performed on the target point cloud data to extract the point cloud normal vectors; Based on the point cloud normal vectors, extract the point cloud abrupt change features; Based on the point cloud mutation features, the set of tree crown contour edge points is determined.

[0064] Specifically, Figure 7 This is a schematic diagram of the drip line extraction process provided by the present invention, as shown below. Figure 7 As shown, in the process of extracting the drip line, the edge points of the tree canopy outline are first accurately identified based on the target point cloud data, and the edge lines are extracted. Then, for the set of edge points formed by the edge points of the tree canopy outline, the Alpha Shape algorithm is used to perform concave hull fitting on the set of edge points to generate the drip line boundary that matches the shape of the tree canopy projection.

[0065] For example, in one embodiment, principal component analysis (PCA) is performed on the target point cloud data to calculate the point cloud normal vector, specifically including the following steps: Suppose any point in the target point cloud data k-nearest neighbor set for: covariance matrix for: In the formula, Point of Nearest neighbor set The index of the nearest neighbor points, This indicates the first nearest neighbor in the set of nearest neighbors. Three-dimensional coordinate vectors of neighboring points The transpose operator for matrices.

[0066] Feature decomposition is as follows: in, Represents the eigenvector and the smallest eigenvalue. corresponding feature vector That is, the point cloud normal vector .

[0067] If the angle between the point cloud normal vectors in the neighborhood changes beyond a threshold (For example, if set to 30°), then it is a point cloud mutation feature, and the corresponding feature points are marked as tree canopy outline edge points. : In the formula, Point of Nearest neighbor set, Point The unit normal vector, express midpoint The unit normal vector.

[0068] Based on the tree canopy outline edge points, a set of tree canopy outline edge points is constructed. An Alpha Shape concave hull fitting is performed on the tree canopy outline edge point set P, and the following definition is made: Judgment criteria: When any point in P A concave hull boundary is formed if and only if a radius exists. When the circle is empty (without other points), the boundary of the drip line is ,radius .

[0069] By smoothing the discrete concave vertices in the drip line boundary using B-spline curves, a continuous and smooth drip line navigation path is generated, providing a high-precision spatial trajectory reference for the fertilizer applicator's trenching and fertilization operations. The set of concave boundaries is as follows: By setting the parameter α∈[0.1, 0.5] to control the concavity and convexity of the boundary, the smaller the value, the tighter the envelope, thereby smoothing the discrete concave hull vertices and generating a drip-line navigation path.

[0070] This invention employs an edge detection method based on point cloud normal vector mutation to extract edge points from irregular tree canopy shapes. It stably calculates normal vectors on the irregular point cloud, ensuring the reliability of edge detection and thus obtaining an accurate set of tree canopy outline edge points. Furthermore, it generates drip line boundaries that closely follow the tree canopy projection through Alpha Shape concave hull fitting, avoiding overfitting issues caused by convex hull fitting and thereby improving the accuracy of the drip line navigation path.

[0071] Step 106: Control the fertilizer applicator to open trenches and / or apply fertilizer according to the drip line navigation path.

[0072] Specifically, the edge line of the tree canopy projected vertically to the ground (i.e., the drip line of the tree canopy) is where the root system of the fruit tree is densely distributed. Applying fertilizer by trenching along the drip line of the fruit tree can fully ensure the utilization efficiency of fertilizer, and can also achieve the effect of pruning the root system, thereby promoting the growth of the fruit tree and ensuring the quality of the fruit.

[0073] In this embodiment of the invention, the control system of the fertilizer applicator drives the tracked chassis to move along the drip line navigation path, and controls the ditching and fertilizing devices behind it to operate at the appropriate time, thereby realizing automated ditching and fertilization along the drip line of the fruit trees.

[0074] For example, in one embodiment, by transmitting the drip line coordinates to the fertilizer applicator's controller to calculate the drip line navigation path, the left / right track speed commands of the fertilizer applicator are generated to drive the walking chassis, enabling the entire machine to move precisely along the drip line navigation path; at the same time, the trenching hydraulic cylinder depth adjustment and auger material dropping control are triggered in front of the target work point, realizing the spatiotemporal collaborative operation of the trenching device and the fertilizer applicator, completing the integrated process of trenching-fertilizing-covering soil, wherein the pose feedback closed loop is realized through RTK-GNSS / nine-axis electronic compass multi-sensor fusion, which can achieve a positioning error of ≤±1cm.

[0075] In another embodiment, the human-machine interface of the fertilizer applicator can also be a dual-mode operation, namely automatic mode and semi-automatic mode. In automatic mode, the fertilizer applicator automatically performs trenching and fertilization operations according to the drip line navigation path; when the detection finds that the quality of the point cloud data collected by the two-dimensional lidar is less than a preset threshold (such as the accuracy being less than a certain threshold or the data volume being less than a certain threshold), the fertilizer applicator automatically switches to semi-automatic mode, at which time the relevant thresholds (such as trenching depth or fertilizer application amount) need to be manually set for operation.

[0076] During operation, real-time parameters (including point cloud quality, drip line trajectory, fertilizer balance, etc.) can be displayed on an industrial tablet computer. When the trenching resistance exceeds the limit (e.g., greater than 2000 N·m) or the fertilizer tank is empty (e.g., weight less than 10 kg), the machine will alarm and stop operation, thereby improving operational safety.

[0077] This invention enables fully automated fertilization by precisely controlling the fertilization location near the drip line where the root system is dense, reducing reliance on manual labor. This not only improves fertilization efficiency and precision but also ensures that the fertilizer is fully absorbed by the fruit trees, increasing fertilizer utilization and reducing fertilization costs.

[0078] This invention provides an orchard fertilization method based on drip line detection. It collects position and azimuth data of the fertilizer applicator during its movement through the orchard, providing an accurate vehicle pose reference for subsequent data fusion and ensuring overall spatial consistency. A two-dimensional lidar is used to collect two-dimensional point cloud data of the target fruit trees. The two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are those on either side of the applicator's location. The lidar scans the fruit tree surface to obtain detailed geometric point cloud information, providing the raw data foundation for three-dimensional reconstruction and achieving non-contact canopy morphology acquisition. Based on the timestamps of the two-dimensional point cloud data, the method integrates the position data, azimuth data, and two-dimensional point cloud data. Data is fused to obtain fused point cloud data, which is then aligned with timestamps to eliminate spatiotemporal errors between sensor data, generating fused point cloud data that improves the accuracy and reliability of subsequent 3D reconstruction. Based on the fused point cloud data, the target fruit tree is reconstructed in 3D to obtain target point cloud data, thereby accurately reconstructing the 3D structure of the target fruit tree. Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated, ensuring that the fertilization location accurately corresponds to the dense root zone of the target fruit tree. The fertilizer applicator is controlled to dig trenches and / or fertilize according to the drip line navigation path, thereby realizing automated fertilization operation along the drip line without manual intervention, improving the fertilization efficiency and accuracy in orchard fertilization operations.

[0079] The orchard fertilization device based on drip line detection provided by the present invention will be described below. The orchard fertilization device based on drip line detection described below and the orchard fertilization method based on drip line detection described above can be referred to in correspondence.

[0080] Figure 8 This is a schematic diagram of the orchard fertilization device based on drip line detection provided by the present invention, as shown below. Figure 8 As shown. This embodiment of the invention provides an orchard fertilization device based on drip line detection, comprising a first acquisition module 801, a second acquisition module 802, a point cloud fusion module 803, a three-dimensional reconstruction module 804, a generation module 805, and a control module 806, wherein: The first acquisition module 801 is used to acquire position data and azimuth data of the fertilizer applicator during its operation in the orchard; the second acquisition module 802 is used to acquire two-dimensional point cloud data of the target fruit trees using a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; the point cloud fusion module 803 is used to fuse the position data, the azimuth data, and the two-dimensional point cloud data based on the timestamp of the two-dimensional point cloud data to obtain fused point cloud data; the three-dimensional reconstruction module 804 is used to perform three-dimensional reconstruction of the target fruit trees based on the fused point cloud data to obtain target point cloud data; the generation module 805 is used to generate a drip line navigation path for the target fruit trees based on the target point cloud data; and the control module 806 is used to control the fertilizer applicator to perform trenching and / or fertilization according to the drip line navigation path.

[0081] The orchard fertilization device based on drip line detection provided by this invention collects the position and azimuth data of the fertilizer applicator during its movement through the orchard, providing an accurate vehicle pose reference for subsequent data fusion and ensuring overall spatial consistency. It also collects two-dimensional point cloud data of the target fruit trees using a two-dimensional lidar mounted on the fertilizer applicator. The target fruit trees are located on either side of the fertilizer applicator, allowing the lidar to scan the tree surface and obtain detailed geometric point cloud information, providing the raw data foundation for three-dimensional reconstruction and achieving non-contact canopy morphology acquisition. Based on the timestamps of the two-dimensional point cloud data, the device integrates the position data, azimuth data, and two-dimensional point cloud data. Data is fused to obtain fused point cloud data, which is then aligned with timestamps to eliminate spatiotemporal errors between sensor data, generating fused point cloud data that improves the accuracy and reliability of subsequent 3D reconstruction. Based on the fused point cloud data, the target fruit tree is reconstructed in 3D to obtain target point cloud data, thereby accurately reconstructing the 3D structure of the target fruit tree. Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated, ensuring that the fertilization location accurately corresponds to the dense root zone of the target fruit tree. The fertilizer applicator is controlled to dig trenches and / or fertilize according to the drip line navigation path, thereby realizing automated fertilization operation along the drip line without manual intervention, improving the fertilization efficiency and accuracy in orchard fertilization operations.

[0082] Figure 9 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 9As shown, the electronic device may include: a processor 910, a communication interface 920, a memory 930, and a communication bus 940, wherein the processor 910, the communication interface 920, and the memory 930 communicate with each other via the communication bus 940. The processor 910 can call logical instructions in the memory 930 to execute an orchard fertilization method based on drip line detection, the method including: Collect location and azimuth data of the fertilizer applicator during its operation in the orchard; Two-dimensional point cloud data of the target fruit trees are collected by a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; Based on the timestamp of the two-dimensional point cloud data, the location data, the driving azimuth angle data, and the two-dimensional point cloud data are fused to obtain fused point cloud data; Based on the fused point cloud data, the target fruit tree is reconstructed in three dimensions to obtain the target point cloud data; Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated; The fertilizer applicator is controlled to perform trenching and / or fertilization according to the drip line navigation path.

[0083] Furthermore, the logical instructions in the aforementioned memory 930 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0084] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, wherein when the computer program is executed by a processor, the computer is able to execute the orchard fertilization method based on drip line detection provided by the above methods, the method comprising: Collect location and azimuth data of the fertilizer applicator during its operation in the orchard; Two-dimensional point cloud data of the target fruit trees are collected by a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; Based on the timestamp of the two-dimensional point cloud data, the location data, the driving azimuth angle data, and the two-dimensional point cloud data are fused to obtain fused point cloud data; Based on the fused point cloud data, the target fruit tree is reconstructed in three dimensions to obtain the target point cloud data; Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated; The fertilizer applicator is controlled to perform trenching and / or fertilization according to the drip line navigation path.

[0085] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the orchard fertilization method based on drip line detection provided by the above methods, the method comprising: Collect location and azimuth data of the fertilizer applicator during its operation in the orchard; Two-dimensional point cloud data of the target fruit trees are collected by a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; Based on the timestamp of the two-dimensional point cloud data, the location data, the driving azimuth angle data, and the two-dimensional point cloud data are fused to obtain fused point cloud data; Based on the fused point cloud data, the target fruit tree is reconstructed in three dimensions to obtain the target point cloud data; Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated; The fertilizer applicator is controlled to perform trenching and / or fertilization according to the drip line navigation path.

[0086] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0087] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0088] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0089] In this invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0090] In this application's embodiments, "determine B based on A" means that factor A must be considered when determining B. It is not limited to "B can be determined based solely on A," but should also include: "determine B based on A and C," "determine B based on A, C, and E," "determine C based on A, and further determine B based on C," etc. Additionally, it can include using A as a condition for determining B, for example, "when A meets the first condition, determine B using the first method"; another example, "when A meets the second condition, determine B," etc.; another example, "when A meets the third condition, determine B based on the first parameter," etc. Of course, it can also be a condition where A is a factor in determining B, for example, "when A meets the first condition, determine C using the first method, and further determine B based on C," etc.

[0091] It should also be noted that the terms "target," "first," and "second" in this invention are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, without limiting the number of objects; for example, the first object can be one or more.

[0092] In this invention, the term "multiple" refers to two or more kinds, and other quantifiers are similar.

[0093] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for orchard fertilization based on drip line detection, characterized in that, include: Collect location and azimuth data of the fertilizer applicator during its operation in the orchard; Two-dimensional point cloud data of the target fruit trees are collected by a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; Based on the timestamp of the two-dimensional point cloud data, the location data, the driving azimuth angle data, and the two-dimensional point cloud data are fused to obtain fused point cloud data; Based on the fused point cloud data, the target fruit tree is reconstructed in three dimensions to obtain the target point cloud data; Based on the target point cloud data, a drip line navigation path for the target fruit tree is generated; The fertilizer applicator is controlled to perform trenching and / or fertilization according to the drip line navigation path.

2. The orchard fertilization method based on drip line detection according to claim 1, characterized in that, The process of fusing the location data, the driving azimuth angle data, and the two-dimensional point cloud data based on the timestamp of the two-dimensional point cloud data to obtain fused point cloud data includes: The location data is converted from the world coordinate system to the local coordinate system of the orchard to obtain local coordinate data; Using the timestamp as a time axis, the driving azimuth angle data is matched to the two-dimensional point cloud data according to the time axis by the nearest neighbor matching algorithm to obtain three-dimensional point cloud data; The fused point cloud data is obtained by fusing the local coordinate data and the 3D point cloud data according to the time axis using a piecewise linear interpolation algorithm.

3. The orchard fertilization method based on drip line detection according to claim 2, characterized in that, The step of performing three-dimensional reconstruction of the target fruit tree based on the fused point cloud data to obtain target point cloud data includes: Statistical filtering is performed on the fused point cloud data to obtain filtered point cloud data; The filtered point cloud data is rotated to obtain standard point cloud data; The target fruit tree is reconstructed in three dimensions based on the standard point cloud data to obtain the target point cloud data.

4. The orchard fertilization method based on drip line detection according to claim 3, characterized in that, The step of rotating the filtered point cloud data to obtain standard point cloud data includes: The slope of the travel path of the fertilizer applicator is obtained by curve fitting; the travel path is determined based on the local coordinate data. Based on the slope, calculate the angle between the driving path and the straight line; The filtered point cloud data is rotated based on the included angle to obtain the standard point cloud data.

5. The orchard fertilization method based on drip line detection according to claim 1, characterized in that, The step of generating the drip line navigation path for the target fruit tree based on the target point cloud data includes: Based on the target point cloud data, extract the set of tree crown outline edge points of the target fruit tree; The drip line boundary of the target fruit tree is generated by performing concave hull fitting on the set of edge points of the tree crown outline. The discrete concave vertices in the drip line boundary are smoothed to generate the drip line navigation path.

6. The orchard fertilization method based on drip line detection according to claim 5, characterized in that, The step of extracting the set of tree crown outline edge points of the target fruit tree based on the target point cloud data includes: Principal component analysis is performed on the target point cloud data to extract the point cloud normal vectors; Based on the point cloud normal vectors, extract the point cloud abrupt change features; Based on the point cloud mutation features, the set of tree crown contour edge points is determined.

7. An orchard fertilization device based on drip line detection, characterized in that, include: The first data acquisition module is used to collect the position data and azimuth angle data of the fertilizer applicator during its operation in the orchard. The second acquisition module is used to acquire two-dimensional point cloud data of the target fruit trees using a two-dimensional lidar; wherein, the two-dimensional lidar is mounted on the fertilizer applicator, and the target fruit trees are the fruit trees on both sides of the location of the fertilizer applicator; The point cloud fusion module is used to fuse the location data, the driving azimuth angle data and the two-dimensional point cloud data based on the timestamp of the two-dimensional point cloud data to obtain fused point cloud data. The 3D reconstruction module is used to perform 3D reconstruction of the target fruit tree based on the fused point cloud data to obtain the target point cloud data. The generation module is used to generate the drip line navigation path of the target fruit tree based on the target point cloud data; The control module is used to control the fertilizer applicator to perform trenching and / or fertilization according to the drip line navigation path.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the orchard fertilization method based on drip line detection as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the orchard fertilization method based on drip line detection as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the orchard fertilization method based on drip line detection as described in any one of claims 1 to 6.

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