Advancing control method for plant protection agricultural robot

Abstract

The invention provides an advancing control method for a plant protection agricultural robot, and the method comprises the steps: obtaining measurement data collected by a pair of millimeter wave radars disposed on the robot in a process that the robot advances between the lines of a tree array for the tree array which is arranged line by line at intervals; wherein the millimeter-wave radars are arranged at the designated side end of the robot based on the relative orientation between the millimeter-wave radars and the advancing direction of the robot; determining a relative distance value between the robot and the center line of the two rows of trees and an included angle between the current advancing direction of the robot and the center line based on the measurement data; and according to the relative distance value and the included angle, executing advancing control meeting the collision avoidance requirement on the robot. According to the method provided by the invention, the autonomous driving performance of the robot is remarkably improved.

Description

Technical Field

[0001] This manual relates to the field of intelligent control, and in particular to methods for controlling the movement of agricultural robots used in plant protection. Background Technology

[0002] In orchard environments, the demand for automated machine operations is particularly prominent. Currently, agricultural robots operating in orchards typically rely on GNSS dual-antenna systems or GNSS single antennas combined with magnetic compasses to determine their azimuth and position information, enabling them to autonomously navigate along predetermined paths. To ensure the robots can safely navigate between rows of fruit trees without collisions, it is usually necessary to coordinate with manual pre-marking of points to set the travel route.

[0003] However, this manual tracking operation not only increases operating costs and consumes a large amount of manpower, but also struggles to adapt to the complex and ever-changing orchard environment in practical applications. A more significant problem is that the dense canopy of trees in the orchard severely obstructs satellite signals, causing frequent GNSS signal loss for the robot during its movement. This affects positioning accuracy and can even lead to safety issues such as deviation from the flight path or collisions with trees. Therefore, existing technologies, facing the two key bottlenecks of signal obstruction and manual reliance, are insufficient to meet the requirements for all-weather, highly reliable autonomous operation of agricultural robots. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this specification provides a method for controlling the movement of agricultural robots for plant protection.

[0005] According to a first aspect of the embodiments of this specification, a method for controlling the movement of a plant protection agricultural robot is provided, the method comprising: For an array of trees arranged in alternating rows, as the robot moves between the rows of trees, it acquires measurement data collected by a pair of millimeter-wave radars configured on the robot. Each millimeter-wave radar is configured on a designated side of the robot based on its relative orientation and the robot's direction of travel. Based on the measurement data, the relative distance between the robot and the centerline of the two rows of trees, as well as the angle between the robot's current direction of travel and the centerline, are determined. Referring to the relative distance and the angle, the robot performs collision avoidance control.

[0006] In one embodiment, the pair of millimeter-wave radars are respectively disposed on the front and rear sides of the robot, with the front side corresponding to the robot's default straight-line forward movement direction.

[0007] In one embodiment, determining the relative distance between the robot and the centerlines of the two rows of trees based on the measurement data includes: obtaining the row spacing value between the two rows of trees; and determining the relative distance between the robot and the centerlines of the two rows of trees based on the obtained row spacing value and the measurement data.

[0008] In one embodiment, determining the relative distance between the robot and the centerlines of the two rows of trees based on the obtained row spacing value and the measurement data includes: in response to obtaining the row spacing value, constructing a solution relationship for the relative distance value based on the row spacing value and a pair of measurement data returned from two trees in the two rows of trees to obtain the solution value of the relative distance value; wherein, in the XOZ plane formed by the robot's forward movement and the robot's vertical movement, the two trees are located on the same side of the XOZ plane, and different measurement data in the pair of measurement data are acquired by different millimeter-wave radars in the pair of millimeter-wave radars.

[0009] In one embodiment, the solution relation includes: ; ;in, d The value of D represents the relative distance between the centerline of the two rows of trees and the robot, and the value of D represents the row spacing between the two rows of trees. This represents the relative distance between the robot's geometric center and one of the rows of trees. and These represent the angles between the radar return beams reflected from the first tree at the front right side and the first tree at the rear right side of the robot, and the OX axis in the XOZ plane, respectively. and This represents the relative distance between each tree in the two trees and the OX axis in the XOZ plane. This represents the geometric length of the robot along the OX axis in the XOZ plane.

[0010] In one embodiment, determining the relative distance between the robot and the centerline of the two rows of trees based on the obtained row spacing value and the measurement data includes: in response to the failure to obtain the row spacing value, constructing a solution relationship for the relative distance value based on two pairs of measurement data returned from four trees in the two rows of trees to obtain the solution value of the relative distance value; wherein, the trees corresponding to different pairs of measurement data in the two pairs of measurement data come from different rows in the two rows of trees; wherein, for each pair of measurement data in the two pairs of measurement data, the two trees corresponding to the measurement data are located on the same side of the XOZ plane, and the different measurement data are acquired by different millimeter-wave radars in the pair of millimeter-wave radars, and the XOZ plane is formed by the robot's forward straight movement and the robot's vertical direction.

[0011] In one embodiment, the solution relation includes: ; ;in, d The value of D represents the relative distance between the centerline of the two rows of trees and the robot, and the value of D represents the row spacing between the two rows of trees. and This represents the relative distance between the robot's geometric center and each of the trees in the two rows of trees. , , and The four trees represent the first tree at the front left, the second tree at the rear left, the first tree at the front right, and the first tree at the rear right, respectively. The other four trees represent the angles between the radar return beams reflected by the four trees and the OX axis in the XOZ plane. and This represents the relative distance between each of the four trees and the OX axis in the XOZ plane. This represents the geometric length of the robot along the OX axis in the XOZ plane.

[0012] In one embodiment, the angle between the robot's current direction of travel and the centerline is calculated using the following formula: ;in, The angle between the robot's current direction of travel and the centerline.

[0013] In one embodiment, the step of performing collision avoidance-satisfying movement control on the robot by referring to the relative distance value and the included angle includes: performing movement control on the robot based on a control expectation value; wherein the control expectation value includes the relative distance value being zero and the included angle being zero.

[0014] In one embodiment, acquiring measurement data collected by each of a pair of millimeter-wave radars configured on the robot includes: performing collision avoidance-compliant movement control on the robot based on Global Navigation Satellite System (GNSS) signals; and acquiring measurement data collected by each of the pair of millimeter-wave radars configured on the robot in response to the loss of the GNSS signals.

[0015] The technical solutions provided in the embodiments of this specification can include the following beneficial effects: A pair of millimeter-wave radars configured on a plant protection agricultural robot acquire measurement data, which can penetrate the mist formed by plant protection liquid, accurately determine the relative distance between the robot and the centerline of two rows of trees, as well as the angle between the robot's direction of travel and the centerline of the trees, thereby avoiding the control failure problem caused by GNSS signal loss in traditional methods. This method eliminates the need for manual marking, effectively solving the collision problem caused by signal loss or interference of plant protection liquid mist on the lidar when the plant protection agricultural robot travels between rows in orchards, and significantly improving the robot's autonomous driving performance.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this specification and, together with the description, serve to explain the principles of this specification.

[0018] Figure 1 This is a flowchart illustrating a method for controlling the movement of a plant protection agricultural robot according to an exemplary embodiment.

[0019] Figure 2 A schematic diagram of a robot body coordinate system and the configuration position of a millimeter-wave radar is shown.

[0020] Figure 3 This diagram illustrates the row-to-row movement of a crop protection agricultural robot.

[0021] Figure 4 A schematic diagram of geometric analysis based on a pair of measurement data is shown.

[0022] Figure 5 A schematic diagram of a geometric analysis based on two pairs of measurement data is shown.

[0023] Figure 6 A complete control flow diagram is shown in this specification. Detailed Implementation

[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this specification as detailed in the appended claims.

[0025] The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this specification. The singular forms “a,” “the,” and “the” as used in this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0026] It should be understood that although the terms first, second, third, etc., may be used in this specification to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this specification, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0027] In related technologies, agricultural robots operating in orchard environments typically rely on a dual-antenna GNSS system or a single GNSS antenna combined with a magnetic compass to determine their azimuth and position, enabling them to autonomously navigate along a predetermined path. To ensure the robot can safely navigate between rows of fruit trees without collisions, it is usually necessary to manually mark points in advance to set the travel route. However, this manual marking operation not only increases operating costs and consumes a large amount of manpower, but also struggles to adapt to the complex and ever-changing orchard environment in practical applications. A more prominent problem is that the dense canopy of trees in the orchard can severely obstruct satellite signals, causing frequent GNSS signal loss during the robot's movement, which in turn affects positioning accuracy and may even lead to safety issues such as deviation from the flight path or collisions with trees.

[0028] To address the aforementioned issues in related technologies, some further related technologies consider using lidar combined with SLAM to enable agricultural robots to autonomously and safely navigate through forests in the absence of GNSS signals. However, the mist generated by pesticide spraying by plant protection robots can severely interfere with lidar.

[0029] Therefore, considering that millimeter-wave radar can accurately determine the distance between the robot and trees after effectively penetrating the mist formed by pesticide spraying, this specification proposes using millimeter-wave radar for the positioning and movement control of the agricultural robot. In some preliminary attempts, a single millimeter-wave radar was considered to assist the agricultural robot in movement control. However, since a single millimeter-wave radar can only measure the distance between the robot and the trees and the angle between the radar signal line and the robot body, it cannot autonomously determine the robot's azimuth angle relative to the trees. Since the agricultural robot needs to autonomously determine its azimuth angle relative to the trees and its distance from trees on both sides to ensure safe movement, this specification designs an autonomous navigation and positioning scheme based on dual millimeter-wave radar to simultaneously determine the azimuth angle relative to the trees and the distance from trees on both sides, thereby enabling the agricultural robot to move autonomously and safely in the forest.

[0030] The embodiments described in this specification will now be described in detail.

[0031] like Figure 1 As shown, Figure 1 This is a flowchart illustrating a method for controlling the movement of an agricultural robot according to an exemplary embodiment, comprising the following steps S101 to S103: S101. For an array of trees arranged in rows, during the process of the robot moving between the rows of the tree array, the robot acquires the measurement data collected by a pair of millimeter-wave radars configured on the robot.

[0032] Each millimeter-wave radar is positioned on a designated side of the robot based on the relative orientation between the radars and the robot's direction of travel.

[0033] S102. Based on the measurement data, determine the relative distance between the robot and the centerline of the two rows of trees, as well as the angle between the robot's current direction of travel and the centerline.

[0034] S103. Based on the relative distance and included angle, perform collision avoidance driving control on the robot.

[0035] The method described in this manual utilizes a pair of millimeter-wave radars mounted on an agricultural robot to acquire measurement data. These radars can penetrate the mist formed by pesticide spraying, accurately determining the relative distance between the robot and the centerlines of two rows of trees, as well as the angle between the robot's direction of travel and the tree centerlines. This avoids the control failure problem caused by GNSS signal loss in traditional methods. This method eliminates the need for manual marking, effectively solving the collision problem caused by signal loss or lidar interference when the agricultural robot travels between rows in orchards, significantly improving the robot's autonomous driving performance.

[0036] In some embodiments, the movement of the agricultural robot is controlled primarily by Global Navigation Satellite System (GNSS) signals. If the GNSS signal is lost, the aforementioned method is used to perform movement control that avoids collisions.

[0037] For example, in some specific embodiments, the following steps S201 to S204 are included: S201. For an array of trees arranged in alternating rows, during the process of the robot moving between the rows of trees, the robot performs movement control that meets the requirements of collision avoidance based on GNSS signals.

[0038] Among them, the movement control of the robot based on GNSS signals to avoid collisions can be carried out by providing the operator with orientation instructions based on GNSS signals during manual control, or by the robot performing autonomous control after calculating the orientation based on GNSS signals.

[0039] S202. In response to the loss of GNSS signal, acquire the measurement data collected by each of the pair of millimeter-wave radars configured on the robot.

[0040] S203. Based on the measurement data, determine the relative distance between the robot and the centerline of the two rows of trees, as well as the angle between the robot's current direction of travel and the centerline.

[0041] S204. Based on the relative distance and included angle, perform collision avoidance driving control on the robot.

[0042] In the embodiments described in this specification, high-quality travel control is provided based on GNSS signals on the one hand, and collision avoidance is provided based on millimeter-wave radar measurement data when GNSS signals are lost on the other hand, thus providing high-quality travel control while ensuring the safety of robot travel.

[0043] In the embodiments described in this specification, each millimeter-wave radar is configured on a designated side of the robot based on the relative orientation between the millimeter-wave radars and the robot's direction of travel.

[0044] In some embodiments, millimeter-wave radars can theoretically be configured on any side of the robot, provided that angle-based calculations are feasible. To simplify calculations, the orientation of two millimeter-wave radars must satisfy a right-angle or straight-angle relationship. For example, they can be configured on any two sides of the robot, front, back, left, or right.

[0045] Considering that in the actual operating environment of agricultural robots, placing millimeter-wave radar on the left or right side of the robot would affect data accuracy due to the measurement distance being too close to the trees, thus affecting the accuracy of calculating the robot's orientation.

[0046] Therefore, as a preferred embodiment, it is considered to configure a pair of millimeter-wave radars on the front and rear sides of the robot, respectively.

[0047] Figure 2 A schematic diagram of a robot body coordinate system and the configuration position of a millimeter-wave radar is shown.

[0048] like Figure 2 As shown, the coordinate system and millimeter-wave radar installation are defined. The central rectangle represents the agricultural robot body, and the two smaller rectangles on the sides represent tracks or wheels. The direction of rolling along the tracks or wheels is the robot's travel direction. The body coordinate system OXYZ is defined, where the robot's geometric center (in this example, idealized as equivalent to the centroid) is defined as O. The OX axis of the body coordinate system is defined as the direction of travel from O along the robot's longitudinal axis towards the front of the robot (the front is user-specified). The OZ axis is perpendicular to the OX axis and points upwards. The OY axis is obtained based on the right-hand rule, given the known OZ and OX axes. The front millimeter-wave radar is mounted on the front of the robot, ensuring that it emits a beam in the positive direction towards the OX axis of the robot's body coordinate system, while the rear millimeter-wave radar emits a beam in the negative direction towards the OX axis. The beam centerlines of both the front and rear millimeter-wave radars coincide with the OX axis of the body coordinate system and lie on the robot's longitudinal axis. Among them, agricultural robots for plant protection are robots that use two rows of tracks or two rows of wheel hubs for movement control. The "front" specifically refers to the robot's default straight-line forward movement direction. Taking a tracked robot as an example, straight-line forward movement means the robot's direction of travel when both tracks rotate at the same speed.

[0049] In some embodiments, determining the relative distance between the robot and the centerline of two rows of trees based on measurement data includes: acquiring the row spacing value between the two rows of trees; and, based on the acquisition result of the row spacing value and in conjunction with the measurement data, determining the relative distance between the robot and the centerline of the two rows of trees.

[0050] In this manual, the relative distance between the robot and the centerlines of two rows of trees can be calculated directly based on the measurement data from millimeter-wave radar. If the row spacing between the two rows of trees is known, the calculation process can be further simplified based on the known row spacing. Therefore, this manual provides specific calculation methods for the relative distance between the robot and the centerlines of two rows of trees, for both cases where the row spacing value is obtained and cases where the row spacing value is not obtained. For ease of understanding, the following description is accompanied by illustrations.

[0051] Figure 3 This diagram illustrates the row-to-row movement of a crop protection agricultural robot.

[0052] like Figure 3 As shown, under ideal conditions, the robot's direction of travel remains parallel to the two rows of trees.

[0053] The two rows in the tree array closest to the robot are represented by A1 and A2. Each tree is represented by a two-digit number, where the first digit indicates the row the tree belongs to, and the second digit indicates the tree's index within that row. For example, tree 2_i indicates that the tree belongs to row A2 and is the i-th tree in row A2.

[0054] The millimeter-wave radar is represented by O1 and O2. The millimeter-wave radar O1, located at the front, emits a beam in the positive direction of the robot's body coordinate system OX axis, illuminating the tree rows A1 and A2. The millimeter-wave radar O2, located at the rear, emits a beam in the negative direction of the robot's body coordinate system OX axis, illuminating the tree rows A1 and A2.

[0055] In this system, the lines connecting the radar signal transmission point and the reflection point are parallel to the XOY plane and lie within the same plane. The millimeter-wave radar measurement data is represented using a three-digit numbering system. The first digit indicates whether the measurement data was returned from the left or right side of the XOZ plane; the second digit identifies the millimeter-wave radar number to which the measurement data belongs; and the third digit identifies the distance order of the measurement data measured by the same millimeter-wave radar within the left (or right) side of the XOZ plane. For example, as... Figure 3 As shown, the effective radar ranging signals obtained by the front millimeter-wave radar on the left front of the XOZ plane are named L1_1, L1_2, etc., in the counterclockwise direction. The effective radar ranging signals obtained by the rear millimeter-wave radar on the left side of the XOZ plane are named L2_1, L2_2, etc., in the counterclockwise direction. The effective radar ranging signals obtained by the front millimeter-wave radar on the right side of the XOZ plane are named R1_1, R1_2, etc., in the counterclockwise direction. The effective radar ranging signals obtained by the rear millimeter-wave radar on the right side of the XOZ plane are named R2_1, R2_2, etc., in the counterclockwise direction.

[0056] For example, L1_1 indicates that the measurement data is returned from the left side of the XOZ plane, emitted and retrieved by the millimeter-wave radar O1, and that among the various measurement data retrieved by the millimeter-wave radar O1 on the left side of the XOZ plane, this measurement data corresponds to the farthest measurement distance.

[0057] The front millimeter-wave radar is mounted on the front of the vehicle and emits a beam in the positive direction of the robot's coordinate system OX axis to illuminate the tree rows A1 and A2. The rear millimeter-wave radar emits a beam in the negative direction of the robot's coordinate system OX axis to illuminate the tree rows A1 and A2.

[0058] Furthermore, based on the above embodiments, it should be noted that the underscore (_) in this specification is a separator set to increase the readability of the view and does not represent any meaning in itself.

[0059] In one implementation, based on the obtained line spacing value and combined with measurement data, the relative distance between the robot and the centerline of two rows of trees is determined, including: in response to obtaining the line spacing value, constructing a solution relationship for the relative distance value based on the line spacing value and a pair of measurement data returned via two trees in the two rows of trees, so as to obtain the solution value of the relative distance value.

[0060] In the XOZ plane formed by the robot's forward and vertical directions, the two trees are located on the same side of the XOZ plane, and different measurement data in a pair of measurement data are collected by different millimeter-wave radars in a pair of millimeter-wave radars.

[0061] As a specific embodiment, when the line spacing value is obtained, a pair of measurement data is selected from the measurement data from each returning beam for formula calculation. For example, the measurement data corresponding to the returning beams reflected by two trees identified as R11 and R21 are selected to construct the calculation relationship. Specifically, the calculation relationship is as follows: ; ; in, d The value of D represents the relative distance between the centerline of the two rows of trees and the robot, and the value of D represents the row spacing between the two rows of trees. This represents the relative distance between the robot's geometric center and one of the rows of trees. and These represent the angles between the radar return beams reflected from the first tree at the front right side and the first tree at the rear right side of the robot, and the OX axis in the XOZ plane, respectively. and This represents the relative distance between each tree in the two trees and the OX axis in the XOZ plane. This represents the geometric length of the robot along the OX axis in the XOZ plane.

[0062] In another implementation, based on the obtained row spacing value and combined with the measurement data, the relative distance between the robot and the centerline of the two rows of trees is determined, including: in response to the failure to obtain the row spacing value, constructing a solution relationship for the relative distance value based on two pairs of measurement data returned from four trees in the two rows of trees, so as to obtain the solution value of the relative distance value.

[0063] Among them, the trees corresponding to different pairs of measurement data in the two pairs of measurement data come from different rows of trees in the two rows of trees.

[0064] In each of the two pairs of measurement data, the two trees corresponding to the measurement data are located on the same side of the XOZ plane, and different measurement data are collected by different millimeter-wave radars in a pair of millimeter-wave radars. The XOZ plane is formed by the robot's straight forward movement and the robot's vertical direction.

[0065] As a specific embodiment, when the line spacing value is obtained, two pairs of measurement data are selected from the measurement data from each returned beam for formula calculation. For example, the measurement data corresponding to the returned beams reflected by two trees identified as R11 and R21 are selected as one pair of measurement data, and the measurement data corresponding to the returned beams reflected by two trees identified as L11 and L22 are selected as the other pair of measurement data, thus constructing a calculation relationship. Specifically, the calculation relationship is as follows: .

[0066] .

[0067] in, d The value of D represents the relative distance between the centerline of the two rows of trees and the robot, and the value of D represents the row spacing between the two rows of trees. and This represents the relative distance between the robot's geometric center and each of the trees in the two rows of trees. , , and The four trees represent the first tree at the front left, the second tree at the rear left, the first tree at the front right, and the first tree at the rear right, respectively. The other four trees represent the angles between the radar return beams reflected by the four trees and the OX axis in the XOZ plane. and This represents the relative distance between each of the four trees and the OX axis in the XOZ plane. This represents the geometric length of the robot along the OX axis in the XOZ plane.

[0068] In the embodiments described in this specification, the angle between the robot's current direction of travel and the centerline can be calculated using a pair of measurement data.

[0069] As a specific embodiment, for either of the two implementation methods described above, a pair of measurement data shared by both methods can be used for calculation. Specifically, the measurement data corresponding to the reflected beams from the two trees identified as R11 and R21 are selected, and the angle between the robot's current direction of travel and the centerline is calculated using the following formula: .

[0070] in, The angle between the robot's current direction of travel and the centerline.

[0071] In the above embodiment, the distance between the center lines of the robot's geometric center distance lines A1 and A2 is: d The azimuth angle of the robot relative to the tree is To ensure that the robot's geometric center is always kept on the same midline as distance lines A1 and A2, and that the robot's OX axis is parallel to the direction of the trees, in some embodiments, the robot's movement control is performed to meet collision avoidance requirements, with reference to relative distance values ​​and included angles. This includes performing movement control on the robot based on control expectation values.

[0072] The control expectation values ​​include a relative distance value of zero and an included angle value of zero. That is, d =0, =0.

[0073] In some specific embodiments, the lines connecting the radar signal transmission point and the reflection point are parallel to the XOY plane and lie in the same plane. The measurement data are named according to tree identification. For example, the effective radar measurement data obtained by the front millimeter-wave radar on the left front of the XOZ plane are named L1_1, L1_2, etc., in a counterclockwise direction. The effective radar measurement data obtained by the left rear millimeter-wave radar on the XOZ plane are named L2_1, L2_2, etc., in a counterclockwise direction. The effective radar measurement data obtained by the right front millimeter-wave radar on the XOZ plane are named R1_1, R1_2, etc., in a counterclockwise direction, and the effective radar measurement data obtained by the right rear millimeter-wave radar on the XOZ plane are named R2_1, R2_2, etc., in a counterclockwise direction.

[0074] Subsequently, on the same side of the XOZ plane, an effective radar measurement data pair is formed by arbitrarily selecting one effective radar measurement data from the front millimeter-wave radar and one effective radar measurement data from the rear millimeter-wave radar. For example, combinations such as L1_1 and L2_1 (left side of the XOZ plane), L1_1 and L2_2 (left side of the XOZ plane), L1_2 and L2_1 (left side of the XOZ plane), L1_2 and L2_1 (left side of the XOZ plane), R1_1 and R2_1 (right side of the XOZ plane), R1_1 and R2_2 (right side of the XOZ plane), R1_2 and R2_1 (right side of the XOZ plane), and R1_2 and R2_1 (right side of the XOZ plane) can be selected. Further, geometric analysis is performed based on the obtained row spacing values ​​between the two rows of trees. For ease of understanding, a specific geometric analysis process is shown below.

[0075] Figure 4 A schematic diagram of geometric analysis based on a pair of measurement data is shown.

[0076] For example, such as Figure 4 As shown, when the relative distance value is not obtained, i.e., the relative distance value is unknown, it is only necessary to select any one pair of data combinations; here, the combination of R1_1 and R2_1 is selected. The geometric length of the robot in the OX axis direction is... ,like Figure 4 As shown, the distances to the trees obtained by radar data R1_1 and R2_1 are respectively and The angles between the lines connecting the emission points and reflection points of data R1_1 and R2_1 and the OX axis of the body coordinate system are respectively... and .like Figure 4 As shown, removing other data lines and considering only R1_1 and R2_1, A3 is a line that passes through the geometric center O and is parallel to A1 and A2. The intersection points of data lines R1_1 and R2_1 with line A2 are points respectively. With point , The extension of the axis intersects line A1 and line A2 at points respectively. With point From point Points and points Draw perpendicular lines and lines respectively Intersect at point With point From point Draw a perpendicular line that intersects line A3 at point A3. Line A3 and line The lines intersect at point ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The angle between R1_1 and R1_1 is ,Wire The angle between line A2 and line A2 is ,Wire The angle between line A2 and line A2 is ,Wire With lines The included angle is .

[0077] According to the Pythagorean theorem, the relationship between the distance values ​​is expressed as follows: ; Consider triangles With triangle Given similar triangles, the relationship between the distance values ​​can be expressed as follows: ; Furthermore, we can obtain: ; Combining the relationships between the distance values ​​determined by the Pythagorean theorem, the formula can be further written as: ; Furthermore, according to the Pythagorean theorem, angles can be represented based on distance values, such as: ; Combining the relationships between the above distance values, and The expression can be further written as: ; According to geometric relationships, the azimuth angle of the robot relative to the direction of the tree is... At the same time, it can be known from the parallel relationship that This relationship can be further represented as follows: ; Furthermore, according to the Pythagorean theorem, the distance from the robot's geometric center O to line A2 is... It can be represented as follows: ; Furthermore, on the one hand, combining the relationships between the above distance values, The expression and The expression, on the other hand, combined with It is equal to the geometric length along the OX axis, i.e. , It can be further rewritten as: ; in, , , as well as For distance and angle measured by radar, For geometric dimensions, therefore It can be calculated in real time. Considering the known distance D between A1 and A2, the distance between the center lines of the robot's geometric center distance lines A1 and A2 can be calculated based on the following formula. : ; Based on this, given that the spacing between the two rows of fruit trees is known, the relative distance between the robot's geometric center O and the two rows of fruit trees, as well as the angle between the robot's direction of travel and the centerline, can all be calculated.

[0078] Figure 5 A schematic diagram of a geometric analysis based on two pairs of measurement data is shown.

[0079] like Figure 5 As shown, in addition to R1_1 and R2_1, another pair of radar data can be selected from opposite sides of the XOZ plane; here, the combination of L1_1 and L2_2 is chosen. Figure 5 As shown, the distances to the trees obtained from radar measurement data L1_1 and L2_2 are respectively and The angles between the lines connecting the emission points and reflection points of data R1_1 and R2_1 and the OX axis of the body coordinate system are respectively... and The intersection points of data R1_1 and R2_1 with line A1 are points respectively. With point From point Points and points Draw perpendicular lines and lines respectively Intersect at point With point From point Draw a perpendicular line from point A to line A3, intersecting at point A3. ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The length is ,Wire The length is .

[0080] According to the Pythagorean theorem, the relationship between the distance values ​​is expressed as follows: ; Consider triangles With triangle Given similar triangles, the relationship between the distance values ​​can be expressed as follows: ; Furthermore, we can obtain: ; Combining the relationships between the distance values ​​determined by the Pythagorean theorem, the formula can be further written as: ; According to the Pythagorean theorem, the distance from the robot's geometric center O to line A2 is... for: ; According to geometric relationships, That is, the geometric length in the OX axis direction, i.e. At the same time, it can be known from the parallel relationship that This relationship can be further represented as follows: ; in, , , as well as For distance and angle measured by radar, For geometric dimensions, therefore It can be calculated in real time. Considering the calculation method used in the first implementation, the distance between lines A2 and A3 is calculated as follows: The distance between the center lines of the robot's geometric center distance line A1 and A2 can then be calculated using the following formula. : ; Based on this, when the spacing between the two rows of fruit trees is unknown, the relative distance between the robot's geometric center O and the two rows of fruit trees, as well as the angle between the robot's direction of travel and the centerline, can be calculated.

[0081] Figure 6 A complete control flow diagram is shown in this specification.

[0082] like Figure 6As shown, this manual provides two calculation methods depending on whether the row spacing between the two rows of trees is obtained. When the row spacing is obtained, a pair of measurement data is selected from the same side of the XOZ plane. Using this pair of measurement data and the row spacing value, the relative distance between the robot and the centerlines of the two rows of trees, as well as the angle between the robot's direction of travel and the centerlines, are calculated. When the row spacing is not obtained, two pairs of measurement data are selected, each pair selected from the same side of the XOZ plane. Based on this, the relative distance between the robot and the centerlines of the two rows of trees, as well as the angle between the robot's direction of travel and the centerlines, are calculated using the two pairs of measurement data. Finally, a relative distance of 0 and an angle of 0 are used as the desired control values, and the robot executes travel control to achieve safe control of the robot. This method can solve the safety problem of GNSS-based agricultural robots colliding with trees when GNSS signals are lost. At the same time, it avoids the problem of interference from fog formed by pesticide spraying in lidar combined with simultaneous localization and mapping (SLAM) technology. The proposed solution can enable agricultural robots to drive safely in the forest without the need for personnel to monitor them, saving manpower and effectively improving the autonomous driving performance of agricultural robots in the forest.

[0083] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0084] Other embodiments of this specification will readily occur to those skilled in the art upon consideration of the specification and practice of the invention claimed herein. This specification is intended to cover any variations, uses, or adaptations that follow the general principles of this specification and include common knowledge or customary techniques in the art not claimed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this specification are indicated by the following claims.

[0085] It should be understood that this specification is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this specification is limited only by the appended claims.

[0086] The above description is merely a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of protection of this specification.

Claims

1. A method for controlling the movement of a plant protection agricultural robot, comprising: For an array of trees arranged in rows, as the robot moves between the rows of the tree array, it acquires measurement data collected by a pair of millimeter-wave radars configured on the robot. Each of the millimeter-wave radars is configured on a designated side of the robot based on the relative orientation between the millimeter-wave radars and the robot's direction of travel. Based on the measurement data, the relative distance between the robot and the centerline of the two rows of trees is determined, as well as the angle between the robot's current direction of travel and the centerline. Referring to the relative distance value and the included angle, the robot performs movement control that satisfies collision avoidance.

2. The method for controlling the movement of agricultural robots according to claim 1, characterized in that, The pair of millimeter-wave radars are respectively configured on the front and rear sides of the robot, with the front side corresponding to the robot's default straight-line forward movement.

3. The method for controlling the movement of agricultural robots according to claim 2, characterized in that, Determining the relative distance between the robot and the centerline of the two rows of trees based on the measurement data includes: Obtain the row spacing value between the two rows of trees; Based on the obtained row spacing value and the measurement data, the relative distance between the robot and the centerline of the two rows of trees is determined.

4. The method for controlling the movement of agricultural robots according to claim 3, characterized in that, The determination of the relative distance between the robot and the centerline of the two rows of trees, based on the obtained row spacing value and the measurement data, includes: In response to obtaining the line spacing value, based on the line spacing value and a pair of measurement data returned via two trees in the two rows of trees, a solution relationship for the relative distance value is constructed to obtain the solution value of the relative distance value; In the XOZ plane formed by the robot's forward and vertical directions, the two trees are located on the same side of the XOZ plane, and the different measurement data in the pair of measurement data are acquired by different millimeter-wave radars in the pair of millimeter-wave radars.

5. The method for controlling the movement of a plant protection agricultural robot according to claim 4, characterized in that, The solution relationship includes: ； ； in, d The value of D represents the relative distance between the centerline of the two rows of trees and the robot, and the value of D represents the row spacing between the two rows of trees. This represents the relative distance between the robot's geometric center and one of the rows of trees. and These represent the angles between the radar return beams reflected from the first tree at the front right side and the first tree at the rear right side of the robot, and the OX axis in the XOZ plane, respectively. and This represents the relative distance between each tree in the two trees and the OX axis in the XOZ plane. This represents the geometric length of the robot along the OX axis in the XOZ plane.

6. The method for controlling the movement of agricultural robots according to claim 3, characterized in that, The determination of the relative distance between the robot and the centerline of the two rows of trees, based on the obtained row spacing value and the measurement data, includes: In response to the failure to obtain the row spacing value, a solution relationship for the relative distance value is constructed based on two pairs of measurement data returned from four trees in the two rows of trees, so as to obtain the solution value of the relative distance value; Among them, the trees corresponding to different pairs of measurement data in the two pairs of measurement data come from different rows in the two rows of trees; Specifically, for each pair of measurement data, the two trees corresponding to the measurement data are located on the same side of the XOZ plane, and different measurement data are acquired by different millimeter-wave radars in the pair of millimeter-wave radars. The XOZ plane is formed by the robot's straight forward movement and the robot's vertical movement.

7. The method for controlling the movement of a plant protection agricultural robot according to claim 6, characterized in that, The solution relationship includes: ； ； in, d The value of D represents the relative distance between the centerline of the two rows of trees and the robot, and the value of D represents the row spacing between the two rows of trees. and This represents the relative distance between the robot's geometric center and each of the trees in the two rows of trees. , , and The four trees represent the first tree at the front left, the second tree at the rear left, the first tree at the front right, and the first tree at the rear right, respectively. The other four trees represent the angles between the radar return beams reflected by the four trees and the OX axis in the XOZ plane. and This represents the relative distance between each of the four trees and the OX axis in the XOZ plane. This represents the geometric length of the robot along the OX axis in the XOZ plane.

8. The method for controlling the movement of a plant protection agricultural robot according to claim 5 or 7, characterized in that, The angle between the robot's current direction of travel and the centerline is calculated using the following formula: ； in, The angle between the robot's current direction of travel and the centerline.

9. The method for controlling the movement of a plant protection agricultural robot according to claim 1, characterized in that, The step of performing collision avoidance movement control on the robot by referring to the relative distance value and the included angle includes: The robot performs movement control based on the control expectation value; The desired control values ​​include the relative distance being zero and the included angle being zero.

10. The method for controlling the movement of a plant protection agricultural robot according to claim 1, characterized in that, The acquisition of measurement data collected by each of the pair of millimeter-wave radars configured on the robot includes: Based on GNSS signals from the Global Navigation Satellite System, the robot performs movement control that avoids collisions. In response to the loss of the GNSS signal, measurement data collected by each of the pair of millimeter-wave radars configured on the robot are acquired.

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