Three-axis positioning rubber tapping control method and three-axis positioning rubber tapping device

Abstract

The application discloses a three-axis positioning rubber tapping control method and a three-axis positioning rubber tapping device, and relates to the technical field of rubber tapping machines. According to the coordinates of a current position point and the coordinates of a target position point, the three-axis displacement from the current position point to the target position point is calculated, and the three-axis rubber tapping mechanism is controlled according to the three-axis displacement, so that the rubber tapping cutter head works to the target position point. The application realizes automatic control of the rubber tapping work based on the three-axis positioning mode, and compared with the ring positioning mode around the tree, the adaptability and accuracy are improved, and the ring positioning structure around the tree is not needed, so that the structure of the rubber tapping device is simplified and the cost is reduced.

Description

Technical Field

[0001] This application relates to the field of rubber tapping machine technology, and in particular to a three-axis positioning rubber tapping control method and a three-axis positioning rubber tapping device. Background Technology

[0002] Natural rubber is an important industrial raw material and strategic resource, ranking alongside steel, petroleum, and coal as one of the four major industrial raw materials in modern society. It is widely used in industry, national defense, and medicine. Natural rubber originates from rubber trees and is obtained through processing the latex collected after tapping. Tapping refers to the process of cutting away the bark of the rubber tree to collect the latex flowing from the latex ducts along the cut surface; this process is crucial for obtaining natural rubber. my country has strict and clearly defined technical requirements for rubber tree tapping. Tapping too deeply will damage the rubber tree, while tapping too shallowly will not effectively break up enough latex ducts, thus compromising yield.

[0003] Currently, most mainstream automated rubber tapping equipment uses a tree-circling positioning structure and a contour-following method to control the tapping depth. This approach suffers from drawbacks such as complex overall structure, low reliability, high cost, and insufficient adaptability. Summary of the Invention

[0004] The purpose of this application is to provide a three-axis positioning rubber tapping control method and a three-axis positioning rubber tapping device to improve the adaptability and accuracy of rubber tapping work, simplify the structure of the rubber tapping device and reduce costs.

[0005] To achieve the above objectives, this application provides the following solution.

[0006] In a first aspect, this application provides a three-axis positioning rubber cutting control method, including:

[0007] The least squares method was used to obtain the fitted tapping trajectory of the rubber tree;

[0008] The fitted rubber cutting trajectory is discretized to obtain a sequence of position points composed of multiple discrete position points;

[0009] Take the first position point in the position point sequence as the current position point, and take the next position point in the position point sequence as the target position point;

[0010] Calculate the triaxial displacement from the current location point to the target location point based on the coordinates of the current location point and the target location point;

[0011] The three-axis rubber tapping mechanism is controlled according to the three-axis displacement, so that the rubber tapping head works to the target position point, the target position point is taken as the current position point, and the next position point of the current position point is obtained in the position point sequence as the target position point. The process of "calculating the three-axis displacement from the current position point to the target position point based on the coordinates of the current position point and the coordinates of the target position point" is repeated until the rubber is tapped to the last position point in the position point sequence.

[0012] Secondly, this application provides a three-axis positioning rubber tapping device, which includes: a moving platform, a three-axis rubber tapping mechanism, and a control system; the three-axis rubber tapping mechanism is disposed on the moving platform, and the control end of the three-axis rubber tapping mechanism is connected to the control system; the control system is used to control the three-axis rubber tapping mechanism to perform rubber tapping using the above-mentioned three-axis positioning rubber tapping control method.

[0013] According to the specific embodiments provided in this application, this application has the following technical effects.

[0014] This application provides a three-axis positioning rubber tapping control method and a three-axis positioning rubber tapping device. Based on the coordinates of the current position point and the target position point, this application calculates the three-axis displacement from the current position point to the target position point. The three-axis rubber tapping mechanism is controlled according to the three-axis displacement, so that the tapping head works to the target position point. This application realizes automatic control of rubber tapping work based on three-axis positioning. Compared with the tree-circling positioning method, it has improved adaptability and accuracy, and does not require a tree-circling positioning structure, which simplifies the structure of the rubber tapping device and reduces costs. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating a three-axis positioning rubber cutting control method provided in an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of a three-axis positioning rubber cutting control method provided in an embodiment of this application.

[0018] Figure 3 This is a schematic diagram of the structure of a three-dimensional cylindrical polar coordinate system provided in an embodiment of this application.

[0019] Figure 4This is an overall structural diagram of a three-axis positioning rubber cutting device provided in an embodiment of this application.

[0020] Figure 5 This is a top view of a three-axis positioning rubber cutting device provided in an embodiment of this application.

[0021] Figure 6 This is a schematic diagram of the structure of a three-axis rubber cutting mechanism provided in an embodiment of this application.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1. Chassis main body; 2. Walking mechanism; 3. Steering mechanism; 4. Suspension mechanism; 5. Three-axis rubber cutting mechanism; 6. Y-axis linear module; 7. First connecting piece; 8-1. X-axis linear module; 8-2. Z-axis linear module; 9. Profile frame; 10. Rubber cutting head; 11. Second connecting piece; 12. Limit switch; 13. Linear guide rail; 14. Extended nut and washer; 15. Depth camera. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] In one exemplary embodiment, such as Figure 1 and Figure 2 As shown, a three-axis positioning rubber cutting control method is provided, including the following steps:

[0027] Step 101: Use the least squares method to obtain the fitted tapping trajectory of the rubber tree.

[0028] Step 102: Discretize the fitted rubber cutting trajectory to obtain a sequence of position points composed of multiple discrete position points.

[0029] Step 103: Take the first position point in the position point sequence as the current position point, and take the next position point in the position point sequence as the target position point.

[0030] Step 104: Calculate the triaxial displacement from the current position to the target position based on the coordinates of the current position and the target position.

[0031] Step 105: Control the three-axis rubber tapping mechanism according to the three-axis displacement, so that the rubber tapping head works to the target position point, take the target position point as the current position point, and obtain the next position point of the current position point in the position point sequence as the target position point. Return to the step of "calculate the three-axis displacement from the current position point to the target position point based on the coordinates of the current position point and the coordinates of the target position point" until the rubber is tapped to the last position point in the position point sequence.

[0032] By implementing steps 101-105 above, automatic control of rubber tapping can be achieved. Compared with the method of circular positioning around the tree, it has improved adaptability and accuracy, and does not require a circular positioning structure around the tree, which simplifies the structure of the rubber tapping device and reduces costs.

[0033] In another exemplary embodiment, during rubber tapping, the tapping trajectory is a curve distributed across the surface of the tree trunk. However, since the trunk of a rubber tree is not a standard circle or ellipse, the tapping trajectory is also an irregular, approximately circular arc curve. Therefore, to ensure precise depth control throughout the tapping process, the following method is used to obtain an accurate tapping trajectory: first, the coordinates of a series of points on a finite number of target tapping trajectories are obtained; then, these points are fitted to generate a continuous tapping trajectory, i.e., a fitted tapping trajectory.

[0034] Because the trunk of a rubber tree is cylindrical, using a three-dimensional cylindrical polar coordinate system to describe the trajectory distributed along the trunk is more intuitive, the coordinate representation of points is simpler, and the subsequent conversion to a Cartesian coordinate system is also very straightforward. For example... Figure 3 As shown, the horizontal projection plane of the trajectory is located at the height of the trajectory's starting point, O is the center of the coordinate system, P is any point on the trajectory, (r, θ) is the position of P on the horizontal projection plane, and z represents its height relative to the horizontal projection plane. Therefore, (r, θ, z) can represent the position of point P relative to the origin O.

[0035] After obtaining a series of trajectory point coordinates, least squares fitting is performed first.

[0036] Suppose there are n data points (r i ,θ i ,z i (i = 1, 2, ..., n), determine the fitting function:

[0037]

[0038] Construct an error function E, and for each data point, calculate its actual z value z. i With the fitted function at the corresponding r i and θ i The value of f(r) at that location i ,θ i The difference e)i =z i -f(r i ,θ i Furthermore, to comprehensively consider the errors of all data points and avoid the problem of positive and negative errors canceling each other out, the error squared form is adopted. The error function E is defined as the sum of the squared errors of all data points, i.e.

[0039]

[0040] Where E is the error function, e i Let z be the fitting error of the i-th point on the target rubber tapping trajectory, n be the number of points on the target rubber tapping trajectory, and z be the fitting error of the i-th point on the target rubber tapping trajectory. i Let f(r) be the longitudinal coordinate of the i-th point on the target rubber cutting trajectory in a three-dimensional cylindrical polar coordinate system. i ,θ i Let r be the longitudinal fitted coordinate of the i-th point on the target rubber tapping trajectory. i Let θ be the radial coordinate of the i-th point on the target rubber cutting trajectory in a three-dimensional cylindrical polar coordinate system. i Let a be the angular coordinate of the i-th point on the target rubber cutting trajectory in a three-dimensional cylindrical polar coordinate system. jk Let be the (j, k)th coefficient in the fitted function, where j, k = 0, 1, 2, ..., m, and m is the degree of the polynomial in the least squares fitting. Generally, to fit slightly complex curves, cubic polynomial fitting is used, i.e., m is 3.

[0041] Regarding E about a ij Find the partial derivative For example, for a pq (p,q=0,1,…,m), we have:

[0042]

[0043] Make all Get a containing A system of equations. Solve the system of equations and obtain the coefficients a. ij Substituting the obtained coefficients into the fitting function, i.e., equation (1), yields the final trajectory.

[0044] In another exemplary embodiment, step 101 specifically includes steps 201-203.

[0045] Step 201: Obtain a preset number of points on the target tapping trajectory of the rubber tree.

[0046] Step 202: Establish a three-dimensional cylindrical polar coordinate system with the center of the cross-section of the rubber tree where the starting point of the target tapping trajectory is located as the origin, and the height direction of the rubber tree as the z-axis direction, as follows: Figure 3 As shown.

[0047] Step 203: Determine the coordinates of a preset number of points on the target rubber cutting trajectory in the three-dimensional cylindrical polar coordinate system.

[0048] Step 204: Based on the coordinates of a preset number of points on the target rubber tapping trajectory in the three-dimensional cylindrical polar coordinate system, the least squares method is used to fit and obtain the fitted rubber tapping trajectory of the rubber tree.

[0049] Step 204 can be replaced by steps 301-303.

[0050] Step 301: Construct the fitting function, as shown in Equation (1).

[0051] Step 302: Based on the fitting function and the coordinates of a preset number of points on the target rubber cutting trajectory in the three-dimensional cylindrical polar coordinate system, construct an error function as shown in equation (2).

[0052] Step 303: Set the partial derivative of the error function with respect to each coefficient in the fitting function to 0, and construct a set of coefficient equations as shown in equation (3).

[0053] Step 304: Solve the coefficient equation system using the least squares method to obtain the values ​​of each coefficient in the fitted function.

[0054] Step 305: Substitute the values ​​of each coefficient into the fitting function to obtain the fitted rubber cutting trajectory.

[0055] In another exemplary embodiment, since the movement of the stepper motor is discrete, the continuous trajectory data needs to be discretized into a series of tiny step sizes. A suitable step size accuracy is determined, and the trajectory data is decomposed into discrete position points based on the step size, each position point corresponding to the target position that the stepper motor needs to reach. Step 101 above can be replaced by steps 401-403 below.

[0056] Step 401: Decompose the fitted rubber cutting trajectory into multiple discrete position points according to the preset step size.

[0057] Step 402: Based on the coordinates of each discrete position point in the three-dimensional cylindrical polar coordinate system, use the coordinate transformation formula to determine the coordinates of each discrete position point in the Cartesian coordinate system.

[0058] Step 403: Construct the sequence of location points based on the coordinates of each discrete location point in the Cartesian coordinate system.

[0059] In step 402 above, since the three linear modules constituting the three-axis mechanism are orthogonal to each other, a positioning and cutting method based on the Cartesian coordinate system is formed. Therefore, in order to facilitate its control, the obtained fitted cutting trajectory based on the three-dimensional cylindrical polar coordinate system (r, θ, z) needs to be transformed into the Cartesian coordinate system (x, y, z).

[0060] The coordinate transformation formula between a three-dimensional cylindrical polar coordinate system and a Cartesian coordinate system is as follows:

[0061]

[0062] Replacing r and θ in the original fitted function with x and y, i.e. get

[0063]

[0064] In another exemplary embodiment, in step 104 above, the Cartesian coordinate values ​​are converted into corresponding stepper motor steps based on the parameters of the lead screw module. The number of steps required for the stepper motor on each axis is calculated, and the direction of motion and number of steps for each axis from the current position point to the target position point are determined.

[0065] First, determine the important motor parameters, including the lead screw pitch P, step angle θ, driver microstepping factor N, etc. Assuming the target position point's coordinates in the Cartesian coordinate system are (x, y, z), and the current position point's coordinates in the Cartesian coordinate system are (x0, y0, z0), then the three-axis displacements are Δx = x - x0, Δy = y - y0, and Δz = z - z0, respectively, in mm.

[0066] Next, calculate the number of steps for each axis: Based on the lead screw pitch and the angle rotated by the motor per pulse, calculate the number of steps the stepper motor needs to rotate for each axis. Since the lead screw pitch P represents the distance the slider moves for every 360° rotation of the lead screw, and the angle rotated by the motor per pulse is θ / N, the formula for calculating the number of steps required for each axis is:

[0067]

[0068] For example, assume that the motor parameters of the three-axis stepper motors are the same, as shown in Table 1.

[0069] Table 1 Stepper Motor Parameter Table

[0070] Screw pitch (mm) Lead screw diameter (mm) Maximum travel (mm) Step angle ° Drive segmentation factor 1 6 200 1.8 16

[0071] Then, motion cycle control is performed.

[0072] Extract the coordinate data of the next position point from the position point sequence, convert it into the target number of steps for the stepper motor, and set it into the corresponding target position variable.

[0073] The appropriate pulse frequency is calculated using a speed planning algorithm to determine the stepper motor's movement speed. Here, the simplest calculation algorithm based on the target speed is used: First, determine the target speed v of each axis of the three-axis rubber-cutting mechanism, in mm / s. Given the screw pitch P, step angle θ, microstepping factor N, and the number of steps per motor revolution n = 360 / (θ / N), according to the relationship between speed, displacement, and time v = s / t, in screw drive, the distance the slider moves per motor revolution is equal to the screw pitch P. Therefore, the number of revolutions per second of the motor f1 = v / P, which is converted to the required number of pulses per second, i.e., the pulse frequency f = f1 × n = (v / P) × (360 / (θ / N)). For example, the target speed of the x-axis is v. x =10mm / s, screw pitch P = 1mm, step angle θ = 1.8°, subdivision factor N = 16, then the x-axis pulse frequency f x =(10 / 1)×(360 / (1.8 / 16))=32000Hz.

[0074] The STM32 microcontroller generates pulse signals of a specified frequency via a timer. Based on the calculated number of steps and direction, it sends these pulse signals to the stepper motor starters of the three linear lead screw modules. The drivers then drive the stepper motors to rotate according to the received signals, causing the cutting head of the three-axis rubber-cutting mechanism to move towards the target position. Furthermore, after sending the corresponding number of pulses for each position, it updates the current position variable to match the actual position reached.

[0075] In another exemplary embodiment, step 105 described above may be replaced by steps 501-506.

[0076] Step 501: Calculate the number of steps required for the three-axis stepper motor of the three-axis rubber cutting mechanism to rotate based on the three-axis displacement.

[0077] Step 502: Transmit pulse signals to control the three-axis stepper motors to rotate the required number of steps, and obtain the current position of the rubber cutting head.

[0078] Step 503: Calculate the triaxial position difference and distance between the current position of the rubber tapping head and the target position point.

[0079] Step 504: Determine whether the absolute value of the distance is greater than a preset error threshold, and obtain the determination result.

[0080] Step 505: If the judgment result is yes, then calculate the number of steps the three-axis stepper motor of the three-axis rubber cutting mechanism needs to rotate based on the three-axis position difference, and return to the step of "emitting pulse signals to control the three-axis stepper motor to rotate the required number of steps, and obtaining the current position of the rubber cutting head".

[0081] Step 506: If the judgment result is negative, then determine that the cutting head of the three-axis rubber cutting mechanism has worked to the target position point.

[0082] In an exemplary embodiment, a three-axis positioning rubber tapping device is provided, including: a mobile platform, a three-axis rubber tapping mechanism 5, and a control system; the three-axis rubber tapping mechanism 5 is disposed on the mobile platform, and the control terminal of the three-axis rubber tapping mechanism 5 is connected to the control system; the control system is used to control the three-axis rubber tapping mechanism 5 to perform rubber tapping using the three-axis positioning rubber tapping control method in the above embodiment.

[0083] like Figure 4 and Figure 5 As shown, the aforementioned mobile platform includes: a frame body 1, a walking mechanism 2, a steering mechanism 3, and a suspension mechanism 4. The mobile platform moves along a set route via the rotation of the DC geared motor in the walking mechanism 1, which drives the wheels accordingly. The steering motor in the steering mechanism 3 controls the steering angle in real time, thereby moving the mobile platform to the rubber tree and ensuring that the circular groove of the mobile platform is in close contact with the rubber tree.

[0084] like Figure 6 As shown, the aforementioned three-axis rubber cutting mechanism 5 includes an x-axis linear module 8-1, a y-axis linear module 6, a z-axis linear module 8-2, and a rubber cutting head 10. The host computer is connected to the control system via a serial port and controls the three-axis rubber cutting mechanism 5 to start. Each axis linear module begins to reset and moves to the position of the starting limit switch 12 at the starting point. The signal is fed back to the host computer via the control system, and the movement stops.

[0085] For example, the aforementioned mobile platform is an eight-motor mobile platform. The three-axis rubber tapping mechanism 5 is mounted on the eight-motor mobile platform and mainly consists of three linear modules (x-axis linear module 8-1, y-axis linear module 6, and z-axis linear module 8-2) and several support components and connectors. The three linear modules are orthogonal to each other and control the movement in three different coordinate directions in space, allowing the rubber tapping head 10 fixed at the end to move arbitrarily in space. The depth camera 15 is responsible for acquiring the white rubber marks formed by the latex flowing down the tapping line after the last tapping on the rubber tree trunk, and for segmenting, extracting, and fitting the acquired images to obtain the final tapping trajectory. The camera then controls the motors of the linear modules to drive the rubber tapping head 10 to complete the tapping operation according to the generated trajectory.

[0086] Furthermore, the aforementioned eight-motor moving platform consists of four identical suspension mechanisms 4 mounted on both sides of the vehicle frame body 1, a steering mechanism 3 mounted on the lower connecting plate of the suspension mechanism 4, a flange coupling between the traveling mechanism 2 and the steering mechanism 3 locked with screws, and a threaded hole is opened at the end of the reducer shaft of the steering mechanism 3, which is locked to the drive connecting plate through the shaft end retaining ring.

[0087] Furthermore, the overall structure of the three-axis rubber cutting mechanism 5 includes three linear modules with a stroke of 200mm: an x-axis linear module 8-1, a y-axis linear module 6, and a z-axis linear module 8-2; a linear guide rail 13; multiple profile frames 9; several connecting parts; a rubber cutting head 10; and a depth camera 15. The linear guide rail 13 and one linear module are arranged parallel to each other and vertically mounted on two support columns on the profile frame 9. To ensure that the sliders of both are on the same plane for mounting another horizontally placed linear module, an extended nut and a washer 14 are added at the connection between the linear guide rail 13 and the aluminum profile to compensate for the height difference with the corresponding linear module. Connecting parts (i.e., first connecting part 7 and second connecting part 11) are installed on the linear guide rail 13 on the x-axis linear module 8-1 and the slider of the corresponding z-axis linear module 8-2 to mount the z-axis linear module 8-2. The slider of the z-axis linear module 8-2 is directly connected and fixed to the y-axis linear module, which controls the feed depth, via bolts. The rubber cutting head 10 is mounted on the end of the aluminum profile used to extend the distance, and together with it is mounted on the slider of the y-axis linear module for depth control.

[0088] Furthermore, in the x-axis linear module 8-1, a stepper motor drives a lead screw to rotate, thereby promoting the movement of a slider on the lead screw and pushing the z-axis linear module 8-2, which is fixed thereon, to move vertically. The parallel linear guide rail 13 provides support and transmission, ensuring smooth and precise movement. Similarly, the z-axis linear module 8-2 drives the horizontal movement of the y-axis linear module fixed thereon, which in turn drives the rubber cutting head 10, fixed thereon, to achieve deep feed motion. The superposition of these three directional movements allows the rubber cutting head 10 at the end of the motion chain to move arbitrarily within a limited space.

[0089] The depth camera 15 on the three-axis rubber tapping mechanism 5 collects the color and depth information of the tree trunk, obtains the target rubber tapping trajectory using image processing and other methods, and stores it. Specifically, it includes: a trajectory recognition method based on depth gradient changes. The specific steps are as follows: first, the depth camera captures a depth map; second, the background is quickly removed based on the depth difference between the environment and the tree trunk to determine the tree trunk outline; third, the depth gradient change of each point in the central vertical pixel column is calculated, and the point with the minimum depth gradient is identified as the ROI center; fourth, the ROI is extracted according to an appropriate range; fifth, the ROI region is traversed horizontally, and the point with the minimum depth gradient in each vertical column of pixels is found, and noise points are identified and smoothed based on the vertical distance between adjacent points; all extracted and adjusted target points constitute the rubber tapping trajectory point cloud; the point cloud is fitted with least squares to obtain an accurate and continuous rubber tapping trajectory; the coordinates of the series of data points obtained after discretizing the fitted curve are stored in the form of a text file (such as a CSV file), and then the data is transmitted to an STM32 using serial communication and parsed on the STM32.

[0090] Specifically, the host computer controls the three-axis rubber cutting mechanism 5, which drives the rubber cutting head 10 to move point by point along the position point sequence to perform rubber cutting operations, and resets after all operations are completed.

[0091] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A three-axis positioning rubber cutting control method, characterized in that, The triaxial positioning rubber cutting control method includes: The least squares method was used to obtain the fitted tapping trajectory of the rubber tree; The fitted rubber cutting trajectory is discretized to obtain a sequence of position points composed of multiple discrete position points; Take the first position point in the position point sequence as the current position point, and take the next position point in the position point sequence as the target position point; Calculate the triaxial displacement from the current location point to the target location point based on the coordinates of the current location point and the target location point; The three-axis rubber-tapping mechanism is controlled according to the three-axis displacement, so that the rubber-tapping cutter head works to the target position point, the target position point is taken as the current position point, and the next position point of the current position point is obtained from the position point sequence as the target position point. The process of "calculating the three-axis displacement from the current position point to the target position point based on the coordinates of the current position point and the coordinates of the target position point" is repeated until the rubber is tapped to the last position point in the position point sequence is reached. The method of using least squares to obtain the fitted tapping trajectory of the rubber tree specifically includes: A predetermined number of points are obtained on the target tapping trajectory of the rubber tree. The target tapping trajectory is obtained by: capturing a depth map; quickly removing the background based on the depth difference between the environment and the tree trunk to determine the tree trunk outline; calculating the depth gradient change of each point in the central vertical pixel column, finding the point with the minimum depth gradient and determining it as the ROI center; extracting the ROI within a suitable range; traversing the ROI region horizontally, finding the point with the minimum depth gradient in the pixel set of each vertical column, and identifying noise points based on the vertical distance between adjacent points for smoothing; all extracted and adjusted target points constitute the tapping trajectory point cloud. A three-dimensional cylindrical polar coordinate system is established with the center of the cross-section of the rubber tree, where the starting point of the target rubber tapping trajectory is located, as the origin, and the height direction of the rubber tree as the z-axis direction. Determine the coordinates of a predetermined number of points on the target rubber-cutting trajectory in the three-dimensional cylindrical polar coordinate system; Based on the coordinates of a predetermined number of points on the target rubber tapping trajectory in the three-dimensional cylindrical polar coordinate system, the least squares method is used to fit and obtain the fitted rubber tapping trajectory of the rubber tree. Controlling the triaxial rubber-tapping mechanism based on the triaxial displacement to move the rubber-tapping cutter head of the triaxial rubber-tapping mechanism to the target position point specifically includes: Based on the three-axis displacement, calculate the number of steps the three-axis stepper motor of the three-axis rubber cutting mechanism needs to rotate; The pulse signals are transmitted to control the three-axis stepper motors to rotate the required number of steps, and to obtain the current position of the rubber cutting head; Calculate the triaxial position difference and distance between the current position of the rubber tapping blade and the target position point; Determine whether the absolute value of the distance is greater than a preset error threshold, and obtain the determination result; If the judgment result is yes, then based on the three-axis position difference, calculate the number of steps the three-axis stepper motor of the three-axis rubber cutting mechanism needs to rotate, and return to the step of "emitting pulse signals to control the three-axis stepper motor to rotate the number of steps it needs to rotate, and obtain the current position of the rubber cutting head"; If the judgment result is negative, then the cutting head of the three-axis rubber cutting mechanism is determined to be working at the target position point.

2. The three-axis positioning rubber cutting control method according to claim 1, characterized in that, Based on the coordinates of a predetermined number of points on the target tapping trajectory in the three-dimensional cylindrical polar coordinate system, the fitted tapping trajectory of the rubber tree is obtained using the least squares method, specifically including: Construct the fitting function; An error function is constructed based on the fitting function and the coordinates of a predetermined number of points on the target rubber cutting trajectory in the three-dimensional cylindrical polar coordinate system. Set the partial derivative of the error function with respect to each coefficient in the fitting function to 0, and construct a system of coefficient equations; The least squares method is used to solve the system of coefficient equations to obtain the values ​​of each coefficient in the fitted function; Substituting the values ​​of each coefficient into the fitting function yields the fitted rubber cutting trajectory.

3. The three-axis positioning rubber cutting control method according to claim 2, characterized in that, The error function is: ； in, Let be the error function. Let be the fitting error of the i-th point on the target rubber tapping trajectory, and n be the number of points on the target rubber tapping trajectory. Let be the longitudinal coordinate of the i-th point on the target rubber cutting trajectory in a three-dimensional cylindrical polar coordinate system. Let be the longitudinal fitted coordinate of the i-th point on the target rubber cutting trajectory. Let be the radial coordinate of the i-th point on the target rubber cutting trajectory in a three-dimensional cylindrical polar coordinate system. Let be the angular coordinates of the i-th point on the target rubber cutting trajectory in a three-dimensional cylindrical polar coordinate system. Let be the (j, k)th coefficient in the fitted function, where j, k = 0, 1, 2, ..., m, and m is the degree of the polynomial in the least squares fitting.

4. The three-axis positioning rubber cutting control method according to claim 1, characterized in that, Discretizing the fitted rubber cutting trajectory to obtain a sequence of discrete position points specifically includes: The fitted rubber cutting trajectory is decomposed into multiple discrete position points according to a preset step size; Based on the coordinates of each discrete position point in the three-dimensional cylindrical polar coordinate system, the coordinates of each discrete position point in the Cartesian coordinate system are determined using the coordinate transformation formula. The sequence of position points is constructed based on the coordinates of each discrete position point in the Cartesian coordinate system.

5. The three-axis positioning rubber cutting control method according to claim 1, characterized in that, Based on the aforementioned three-axis displacement, the formula for calculating the number of steps required for the three-axis stepper motor of the three-axis rubber-cutting mechanism to rotate is as follows: ； ； ； in, , , These represent the number of steps the stepper motors need to rotate along the x, y, and z axes, respectively. , , These represent the displacements along the x-axis, y-axis, and z-axis, respectively. , , These are the lead screw pitches of the stepper motors for the x, y, and z axes, respectively. , and These are the step angles of the stepper motors for the x-axis, y-axis, and z-axis, respectively. , , These are the driver subdivision coefficients for the stepper motors on the x, y, and z axes, respectively.

6. A three-axis positioning rubber cutting device, characterized in that, The triaxial positioning rubber cutting device includes: a mobile platform, a triaxial rubber cutting mechanism, and a control system; The three-axis rubber tapping mechanism is mounted on the mobile platform, and the control terminal of the three-axis rubber tapping mechanism is connected to the control system. The control system is used to control the three-axis rubber cutting mechanism to perform rubber cutting using the three-axis positioning rubber cutting control method according to any one of claims 1-5.

7. The triaxial positioning rubber cutting device according to claim 6, characterized in that, The three-axis rubber cutting mechanism includes: an x-axis linear module, a y-axis linear module, a z-axis linear module, and a rubber cutting head; The x-axis linear module is movably mounted on two profile frames, and the two profile frames are fixed on the movable platform; The z-axis linear module is movably mounted on the x-axis linear module, and the y-axis linear module is movably mounted on the z-axis linear module. The rubber cutting head is located at the end of the y-axis linear module; The x-axis linear module, the y-axis linear module, and the z-axis linear module are used to control the movement of the rubber cutting head in the horizontal, depth, and vertical directions, respectively.

8. The triaxial positioning rubber cutting device according to claim 7, characterized in that, The x-axis linear module, y-axis linear module, and z-axis linear module are driven by x-axis, y-axis, and z-axis stepper motors, respectively.

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