Clamping position fitting positioning method of round roller cutting die roller shaft and cladding processing method of roller shaft

Abstract

The invention relates to a method for fitting and positioning the clamping position of a roller shaft of a round roller cutting die, and the method comprises the following steps: S1, fixing a cylindrical roller shaft on a rotary table, and building an OXYZ three-dimensional measurement coordinate system by taking the rotation center axis of the rotary table as a Z axis; s2, selecting a cross section in the extension direction of the roll shaft, selecting a measuring point at the periphery of the cross section, measuring the measuring point by using a measuring tool to obtain three-dimensional coordinate information of the measuring point, and fitting geometric information of the roll shaft; s3, obtaining an equation of the cylindrical surface of the roll shaft based on a point C on the central axis of the roll shaft and a position relation between the point and a straight line, constructing an error function according to an error value existing between the measurement position of the measurement point and the actual radius of the cylinder, carrying out iterative calculation on the error function, and solving to obtain an equation parameter value when the error value is minimum, therefore, the actual position of the roll shaft for eliminating the error is obtained, and fitting of the roll shaft is completed. And S4, generating a new coordinate axis by using the actual central axis of the fitted roll shaft as a Z axis.

Description

Technical Field

[0001] The present invention relates to the technical field of roll cutter laser cladding, and particularly relates to a method for fitting and positioning the clamping position of a roll shaft of a circular roll cutter die and a method for cladding processing of the roll shaft. Background Art

[0002] A roll cutter is a tool used for cutting, slitting or processing materials. A roll cutter generally consists of two parts: a cutter body and a cutting edge. The cutter body is the main part of the roll cutter, usually made of a metal material such as steel or cemented carbide, etc., for providing sufficient strength and support. The cutting edge is located on the surface of the cutter body, which directly contacts the material to be processed for cutting. The shape, sharpness and material quality of the cutting edge directly affect the cutting effect.

[0003] With the continuous development of material science, the requirements of industrial production for the performance of roll cutters are becoming increasingly stringent. Seeking new roll cutter surface strengthening technologies has become an urgent need in the industry. As an advanced surface modification and additive manufacturing technology, laser cladding has received extensive attention and application in industrial production in recent years. Laser cladding technology can form a cladding layer with excellent properties on the material surface, showing great application potential in the field of roll cutter manufacturing and remanufacturing. Laser cladding uses a high-energy laser beam as a heat source to quickly melt the pre-placed or synchronously fed cladding material and form a metallurgical bond with the surface of the substrate metal, thereby forming a cladding layer with specific properties on the substrate surface. The cladding layer has a dense and uniform structure, and its composition and properties can be precisely controlled, which can significantly improve the hardness, wear resistance, corrosion resistance and high-temperature performance of the material surface, etc.

[0004] When applying laser cladding technology to the processing of the cutter line of a roll cutter, after clamping the roll shaft to the machine tool using a multi-jaw chuck, it is necessary for the calibration personnel to use a dial indicator to calibrate and debug the clamping position, so that the rotation axis of the clamped roll shaft coincides with the rotation axis of the machine tool spindle. However, the calibration and debugging process often requires the accumulation of the experience of the calibration personnel, and the calibration time is relatively long (about 30 to 60 minutes for one roll shaft). After each roll shaft of the roll cutter is clamped to the machine tool for cutter line processing, it is necessary for experienced calibration personnel to re-perform the calibration step, which has a great impact on the cladding efficiency of the cutter line of the roll cutter. Moreover, the automation of cladding processing cannot be achieved.

[0005] To solve the problems that when applying existing laser cladding to the cutter line of a roll cutter, it is usually necessary to rely on the experience of workers to use a dial indicator to calibrate the clamping position of the roll shaft, the process takes a long time, and it depends on the experience of the calibration personnel, making it difficult to improve the efficiency and automation ability of cutter line cladding. Summary of the Invention

[0006] Based on this, it is necessary to provide a method for fitting and positioning the clamping position of a roll shaft of a circular roll cutter die and a method for cladding processing of the roll shaft.

[0007] An embodiment of the present invention provides a method for measuring the actual clamping position of a circular roller die roller shaft, including the following steps:

[0008] S1. Fix the cylindrical roller shaft on the turntable, and the turntable can drive the roller shaft to rotate. Taking the rotation center axis of the turntable as the Z-axis, establish a three-dimensional measurement coordinate system OXYZ;

[0009] S2. Select a cross-section in the extending direction of the roller shaft and select measurement points along the circumference of the cross-section. Use a measuring tool to measure the measurement points to obtain the three-dimensional coordinate information of the measurement points; according to the three-dimensional coordinate information of the measurement points on the surface of the roller shaft, fit the geometric information of the roller shaft;

[0010] S3. Based on the point C on the central axis of the roller shaft and the position relationship between the point and the straight line, obtain the equation of the cylindrical surface of the roller shaft. Due to the error value existing between the measurement position of the measurement point and the actual radius of the cylinder, construct an error function, perform iterative calculation on the error function, and solve to obtain the equation parameter value when the error value is the smallest, so as to obtain the actual position of the roller shaft after eliminating the error, complete the fitting of the roller shaft, and make the coordinate data of the measurement points accurate;

[0011] S4. Use the actual central axis of the fitted roller shaft as the Z-axis to generate a new coordinate axis, convert the coordinate data of the original coordinate system into the coordinate data of the new coordinate system, and obtain the coordinates of the actual clamping position.

[0012] Preferably, in step S1, a chuck and a center pin are provided on the turntable. The two ends of the roller shaft are respectively clamped and fixed by the chuck and the center pin. The chuck and the center pin drive the roller shaft to rotate on the turntable. During measurement, the roller shaft rotates one circle on the turntable, and the probe completes the measurement of the measurement points on a cross-section of the roller shaft.

[0013] Preferably, the measuring tool is a ruby probe, and the head of the ruby probe is a ruby ball with a diameter of 2.0 mm.

[0014] Preferably, in step S2, n mutually parallel cross-sections are selected in the extending direction of the roller shaft. On the circumference of any selected cross-section, m measurement points P are respectively selected. The measurement points are located on the circumferential surface of the roller shaft. The number n of cross-sections selected on the roller shaft is ≥ 4, and the number m of measurement points selected on any cross-section of the roller shaft is ≥ 12. The m measurement points on the same cross-section of the roller shaft are spaced at the same distance.

[0015] Preferably, in step S2, use a measuring tool to measure the measurement points selected on the surface of the roller shaft to obtain the three-dimensional coordinate information of the measurement points in the three-dimensional measurement coordinate system;

[0016] According to the three-dimensional coordinate information of the measurement points on the surface of the roller shaft, fit to obtain a circular cross-section of the circumference of the roller shaft;

[0017] According to the obtained circular cross-section by fitting, the first radius r of the circular cross-section is calculated.

[0018] Preferably, the specific steps of step S3 include:

[0019] S301. Set as the direction vector of the central axis of the roller shaft, C(x0, y0, z0) as the point on the central axis of the cylinder, and P(x, y, z) as any point on the circumferential surface of the roller shaft;

[0020] S302. Since the perpendicular distance L from the point P(x, y, z) to the point C on the central axis of the roller shaft is equal to the actual radius r of the cylinder, there is:

[0021] L 2 = r 2 ;

[0022] S303. In actual measurement, there is an error value between the measurement position of the measurement point and the actual radius of the cylinder. Set the error value d between the distance L from the measurement point to the central axis of the cylinder and the radius r of the cylinder i , and the error value is the difference between the distance L and the radius r of the cylinder. Define the error function:

[0023]

[0024] S304. Use the initial radius value r of the roller shaft, the center coordinate of the bottom surface of the roller shaft and the direction vector of the cylinder axis as the initial values. Then, substitute the data and coordinates of the measurement point P into the error function in sequence, and perform iterative calculation on the error function to solve the equation parameter values of the fitted cylindrical surface. When the convergence threshold or the number of iterations is satisfied, stop the iterative calculation to obtain the equation parameter values of the optimal solution. According to the equation of the configured cylindrical surface, complete the fitting of the cylindrical surface to obtain the coordinate information of the actual clamping position of the roller shaft. The position information of the fitted roller shaft includes the fitted axis, the fitted radius and the fitted central axis.

[0025] Preferably, in step S304, the Levenberg-Marquardt algorithm is used to perform iterative solution for the error function, and the initial values used in the iterative calculation are the initial radius value r of the roller shaft, the center coordinate of the bottom surface of the roller shaft and the Z-axis direction vector.

[0026] Preferably, in step S4, obtain the position information of the fitted roller shaft, use the fitted central axis of the roller shaft as the Z'-axis, establish a three-dimensional fitting coordinate system, perform coordinate transformation on the position information of the cylindrical surface to obtain the coordinate data of the cylindrical surface in the new coordinate system, so as to convert the coordinate data in the original coordinate system into the coordinate data in the new coordinate system.

[0027] The present invention also provides a cladding processing method for a roll shaft based on the fitting positioning method of the clamping position of the circular roll cutter die roll shaft, including the steps:

[0028] Step 1: Grind and clean the surface of the roll shaft to remove contaminants on the surface of the roll shaft; fix the roll shaft on the turntable using a three-jaw chuck and a rotary center.

[0029] Step 2: Use a measuring tool to measure the surface of the circumference of the roll shaft to obtain the coordinate data of the measurement points. According to the obtained coordinate data of the measurement points, perform fitting and coordinate transformation of the cylindrical surface of the roll shaft through the above-mentioned measurement method to obtain the coordinate information of the actual clamping position.

[0030] Step 3: According to the coordinate information of the actual clamping position, use path planning software to perform motion trajectory planning and generate the code for the path corresponding to the cladding pattern.

[0031] Step 4: Input the code into the cladding machine tool to perform cladding of the corresponding tool line pattern on the roll shaft.

[0032] The present invention provides an actual position measurement method for fitting positioning of a circular roll cutter die in laser cladding. By combining a measurement probe with a cylinder fitting method, a probe is used to select measurement points on the circumferential cross-section of the roll shaft for detection, and the circumferential cross-section data of the detection points is obtained, so that the fitting data of the cylindrical surface of the roll shaft can be obtained, thereby replacing roll shaft calibration for planning the cladding path. In this way, through the fitting method of the present invention, the fitting data of the cylindrical surface of the roll shaft is obtained, eliminating the clamping and calibration steps in the traditional method and directly measuring without calibration. On the one hand, the method of the present invention reduces the roll shaft calibration time and improves the cladding efficiency. On the other hand, by reducing the influence of human factors in the cladding process, the reliability and automation degree of the cladding process are improved. Description of the Drawings

[0033] The above and other objects, features and advantages of the present invention will become clearer through the preferred embodiments of the present invention shown in the drawings. The same reference numerals indicate the same parts in all the drawings, and the drawings are not deliberately drawn to scale in actual size, with the emphasis on showing the gist of the present invention.

[0034] Figure 1 It is a schematic diagram of the principle of fitting the actual position of the measuring device and the roll shaft in the three-dimensional measurement coordinate system of the embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of the clamping position of the roll shaft in the measuring device of the preferred embodiment of the present invention;

[0036] Measuring probe 9; roll shaft 10; three-jaw chuck 22; rotary center 23. Detailed Embodiments

[0037] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited do not limit the present invention.

[0038] As Figure 1 and Figure 2 shown, the present invention provides a fitting and positioning method for the actual clamping position of a circular roller die roller shaft, including the following steps:

[0039] S1. Fix the cylindrical roller shaft on the turntable. The turntable can drive the roller shaft to rotate. Taking the rotation center axis of the turntable as the Z-axis, establish a three-dimensional measurement coordinate system OXYZ;

[0040] S2. Select a cross-section in the extension direction of the roller shaft and select measurement points along the circumference of the cross-section. Use a measuring tool to measure the measurement points to obtain the three-dimensional coordinate information of the measurement points; according to the three-dimensional coordinate information of the measurement points on the surface of the roller shaft, fit the geometric information of the roller shaft;

[0041] S3. Based on the points C on the central axis of the roller shaft and the positional relationship between the point and the line, obtain the equation of the cylindrical surface of the roller shaft. Due to the error value existing between the measurement position of the measurement point and the actual radius of the cylinder, construct an error function, perform iterative calculation on the error function, and solve for the equation parameter values when the error value is the smallest, so as to obtain the actual position of the roller shaft after eliminating the error, complete the fitting of the roller shaft, and make the coordinate data of the measurement points accurate;

[0042] S4. Use the actual central axis of the fitted roller shaft as the Z-axis to generate a new coordinate axis, convert the coordinate data of the original coordinate system into the coordinate data of the new coordinate system, and obtain the coordinates of the actual clamping position.

[0043] In a preferred embodiment, in step S1, a chuck and a center pin are provided on the turntable. Both ends of the roller shaft are clamped and fixed by the chuck and the center pin respectively. The chuck and the center pin drive the roller shaft to rotate on the turntable. During measurement, the roller shaft rotates one circle on the turntable, and the probe completes the measurement of the measurement points on one cross-section of the roller shaft.

[0044] In a preferred embodiment, the measuring tool is a ruby probe, and the head of the ruby probe is a ruby ball with a diameter of 2.0 mm.

[0045] In a preferred embodiment, in step S2, n mutually parallel cross-sections are selected in the extension direction of the roller shaft. On the circumference of any selected cross-section, m measurement points P are respectively selected. The measurement points are located on the circumferential surface of the roller shaft. The number n of cross-sections selected on the roller shaft is ≥ 4, and the number m of measurement points selected on any cross-section of the roller shaft is ≥ 12. The m measurement points on the same cross-section of the roller shaft are spaced at the same distance.

[0046] In a preferred embodiment, in step S2, a measuring tool is used to measure the selected measurement points on the surface of the roller shaft, and the three-dimensional coordinate information of the measurement points in the three-dimensional measurement coordinate system is obtained;

[0047] According to the three-dimensional coordinate information of the measurement points on the surface of the roller shaft, a circular cross-section of the circumference of the roller shaft is fitted;

[0048] According to the fitted circular cross-section, the first radius r of the circular cross-section is calculated.

[0049] In a preferred embodiment, the specific steps of step S3 include:

[0050] S301. Set is the direction vector of the central axis of the roller shaft, C(x0, y0, z0) is the point on the central axis of the cylinder, and P(x, y, z) is any point on the circumferential surface of the roller shaft;

[0051] S302. Since the perpendicular distance L from the point P(x, y, z) to the point C on the central axis of the roller shaft is equal to the actual radius r of the cylinder, then there is:

[0052] L 2 = r 2 ;

[0053] S303. In actual measurement, there is an error value between the measurement position of the measurement point and the actual radius of the cylinder. Set the error value d between the distance L from the measurement point to the central axis of the cylinder and the radius r of the cylinder i , and the error value is the difference between the distance L and the radius r of the cylinder. Define the error function:

[0054]

[0055] S304. Use the initial radius value r of the roller shaft, the coordinates of the center of the bottom surface of the roller shaft, and the direction vector of the cylinder axis as the initial values. Then, substitute the data and coordinates of the measurement point P into the error function in turn, and perform iterative calculation on the error function to solve the equation parameter values of the fitted cylindrical surface. When the convergence threshold is met or the number of iterations stops, stop the iterative calculation, obtain the equation parameter values of the optimal solution, and complete the fitting of the cylindrical surface according to the equation of the configured cylindrical surface to obtain the coordinate information of the actual clamping position of the roller shaft. The position information of the fitted roller shaft includes the fitted axis, the fitted radius, and the fitted central axis.

[0056] Specifically, the cylindrical surface is a set of points whose distance to its axis is equal to the radius. Therefore, set the direction vector of the central axis of the cylinder as

[0057]

[0058] A certain point C(x0, y0, z0) on the central axis of the cylinder, the radius r of the cylinder, and any point P(x, y, z) in space, then the vector

[0059]

[0060] From the distance from a point to a line, the distance L from point P to the central axis of the cylinder is

[0061]

[0062] Among them,

[0063]

[0064]

[0065] Then

[0066]

[0067] The cylindrical surface can be regarded as the set of points in space whose distance to the central axis of the cylinder is equal to the radius r of the cylinder, then L 2 = r 2 , so the equation of the cylindrical surface is

[0068]

[0069] Let

[0070] u = c(y - y0) - b(z - z0), v = c(x - x0) - a(z - z0), w = b(x - x0) - a(y - y0)

[0071] Then the equation of the cylindrical surface is

[0072]

[0073] There will be an error value between the distance L from point P(x, y, z) to the central axis of the cylinder and the radius of the cylinder. Then the error between the distance from the i-th measurement point to the central axis of the cylinder and the radius of the cylinder is

[0074] d i = L - r

[0075] Define the error function as

[0076]

[0077] So the process of fitting the cylinder is to optimize r, C, such that the error function has a minimum value.

[0078] The Levenberg-Marquardt algorithm is selected in the present invention to solve the error function. This algorithm combines the advantages of the gradient descent method and the Gauss-Newton method, and balances their advantages by adjusting the damping factor. It is a commonly used method for solving non-linear least squares problems. The initial values used are the initial radius value of the roller shaft, the center coordinate of the bottom surface of the roller shaft, and the Z-axis direction vector. Iterative calculations are performed until the threshold is met or the preset number of iterations is reached.

[0079] In the preferred embodiment, in step S304, the Levenberg-Marquardt algorithm is selected to perform iterative solution on the error function. The initial values used in the iterative calculation are the initial radius value r of the roller shaft, the center coordinate of the bottom surface of the roller shaft, and the Z-axis direction vector.

[0080] In the preferred embodiment, in step S4, the position information of the fitted roller shaft is obtained. Taking the central axis of the fitted roller shaft as the Z'-axis, a three-dimensional fitting coordinate system is established, and the position information of the cylindrical surface is subjected to coordinate transformation to obtain the coordinate data of the cylindrical surface in the new coordinate system, thereby converting the coordinate data in the original coordinate system into the coordinate data in the new coordinate system.

[0081] Specifically, in step S4, after the fitting is completed, the axial information of the fitted cylinder will be obtained in the path planning software. At this time, taking the axis of the fitted cylinder as the Z-axis of the new coordinate system, which is defined as the Z'-axis here, then the direction vector of the Z'-axis is Defined as The direction vector is obtained The corresponding unit vector, that is, the unit vector of the Z'-axis is obtained Is

[0082]

[0083] The selected original X-axis vector Is used as the X-axis in the new coordinate system, that is, the initial direction vector of the X'-axis. Calculate the initial direction vector of the X'-axis The projection on the unit vector of the Z'-axis Then from the initial direction vector of the X'-axis Subtract the projection To obtain the X'-axis direction vector orthogonal to the Z'-axis So the unit vector of the X'-axis orthogonal to the Z'-axis

[0084]

[0085] Use the cross product to calculate the Y-axis of the new coordinate system orthogonal to the Z'-axis and X'-axis, that is, the unit vector of the Y'-axis is

[0086]

[0087] Finally, three mutually orthogonal and normalized vectors are obtained, forming a new coordinate system with the axial direction of the fitted cylinder as the Z-axis.

[0088] After that, the coordinate parameters of the original coordinate system are transformed into the coordinate parameters of the new coordinate system. Therefore, the coordinate transformation matrix is Then the new coordinate parameters are

[0089] (x′, y′, z′) = R × (x, y, z)

[0090] So far, the cylindrical fitting of the roller shaft and the coordinate transformation of the new coordinate system are completed. Combining with the path planning, the code corresponding to the cladding pattern can be obtained.

[0091] A cladding processing method for a roller shaft based on the fitting and positioning method of the actual clamping position of the circular roller cutter die roller shaft provided by the present invention includes the steps:

[0092] Step 1: Grind and clean the surface of the roller shaft to remove contaminants on the surface of the roller shaft; fix the roller shaft on the turntable using a three-jaw chuck and a rotary center.

[0093] Step 2: Use a measuring tool to measure the surface of the circumference of the roller shaft to obtain the coordinate data of the measurement points. According to the obtained coordinate data of the measurement points, perform the fitting and coordinate transformation of the cylindrical surface of the roller shaft through the described measurement method to obtain the coordinate information of the actual clamping position.

[0094] Step 3: According to the coordinate information of the actual clamping position, use path planning software to perform motion trajectory planning and generate the code for the path corresponding to the cladding pattern.

[0095] Step 4: Input the code into the cladding machine tool to perform the cladding of the corresponding tool line pattern on the roller shaft.

[0096] To better illustrate the technical solution of the present invention, the following preferred embodiments are further described.

[0097] Embodiment 1

[0098] Step 1: After grinding and cleaning the surface of the roller shaft 10 to be clad, fix the roller shaft using a three-jaw chuck 22 and a rotary center 23. Select the corresponding measurement program in the laser cladding machine tool and use the measurement probe 9 to measure the circumferential surface information of the roller shaft 10. As Figure 2 shown, fix the roller shaft 10 on the turntable using a three-jaw chuck 22 and a rotary center 23. Among them, use a ruby measurement probe 9 to measure the surface of the circumference of the roller shaft. The measurement points in the circumferential direction should be evenly distributed to accurately fit the circular cross-section of the cylinder. The positions of 4 circumferences are evenly distributed in the axial direction of the roller shaft, and each circumferential surface is provided with 12 measurement points, and there are a total of 48 measurement point data.

[0099] Step 2: Read the data of the measurement points on the surface of the roller circumference in the roller cutter path planning software. Use the initial radius value of the roller, the center coordinate of the bottom surface of the roller, and the Z-axis direction vector as the initial values of the error function. Substitute the data and coordinates of the measurement points into the error function respectively, and use the Levenberg-Marquardt algorithm to solve the equation parameter values of the fitted cylindrical surface until the convergence threshold or the number of iterations is met to obtain the optimal solution of the parameters.

[0100] Step 3: Generate a new coordinate axis using the central axis of the fitted cylinder as the Z-axis, convert the coordinate data of the original coordinate system into the coordinate data of the new coordinate system, combine the path planning and scanning strategy of the cladding pattern, output the generated path and display it in the path planning software, and generate the corresponding path code.

[0101] Step 4: Check the generated code and the corresponding roller cutter line pattern in the roller cutter path planning software. After confirming that the cutter line pattern is correct, input the code into the machine tool. Execute the code on the machine tool to complete the cladding process as set.

[0102] After the cladding process is completed, clean the excess powder, remove the roller from the fixture for subsequent processing and performance testing.

[0103] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A fitting positioning method for the clamping position of a circular roller die roller shaft, characterized in that: The steps include: S1. Fix the cylindrical roller on the turntable. The turntable can drive the roller to rotate. The rotation center axis of the turntable is used as the Z axis to establish the OXYZ three-dimensional measurement coordinate system. S2. Select a cross section in the extension direction of the roller, select a measuring point at the periphery of the cross section, use a measuring tool to measure the measuring point, and obtain three-dimensional coordinate information of the measuring point; fit the geometric information of the roller according to the three-dimensional coordinate information of the measuring point on the surface of the roller; S3. Based on the positional relationship between point C on the central axis of the roller and the straight line, the equation of the cylindrical surface of the roller is obtained. According to the error value between the measured position of the measuring point and the actual radius of the cylinder, an error function is constructed. The error function is iteratively calculated to solve the equation parameter value with the minimum error value, thereby obtaining the actual position of the roller to eliminate the error, completing the fitting of the roller, and making the coordinate data of the measuring point accurate. S4. Use the actual center axis of the fitted roller as the Z axis to generate a new coordinate axis, transform the coordinate data of the original coordinate system into the coordinate data of the new coordinate system, and obtain the coordinates of the actual clamping position.

2. The fitting positioning method according to claim 1, characterized in that: In step S1, a chuck and an ejector pin are provided on the turntable, and both ends of the roller are clamped and fixed by the chuck and the ejector pin respectively. The chuck and the ejector pin drive the roller to rotate on the turntable. During measurement, the roller rotates one circle on the turntable, and the probe completes the measurement of a measuring point on a cross section of the roller.

3. The fitting positioning method according to claim 1, characterized in that: The measuring tool shown is a ruby ​​probe, the head of which is a ruby ​​ball with a diameter of 2.0 mm.

4. The fitting positioning method according to claim 3, characterized in that: In step S2, n mutually parallel sections are selected in the extension direction of the roller, and m measuring points P are selected on the circumferential edge of any selected section, the measuring points are located on the circumferential surface of the roller, the number of sections selected on the roller is n≥4, the number of measuring points of any section selected on the roller is m≥12, and the m measuring points on the same roller section are spaced at the same distance.

5. The fitting positioning method according to claim 4, characterized in that: In step S2, a measuring tool is used to measure the selected measuring points on the roller surface to obtain three-dimensional coordinate information of the measuring points in the three-dimensional measurement coordinate system; According to the three-dimensional coordinate information of the measuring points on the roller surface, the circular cross section of the roller circumference is obtained by fitting; According to the circular cross section obtained by fitting, a first radius r of the circular cross section is calculated.

6. The fitting positioning method according to claim 1, characterized in that ,The specific steps of step S3 include: S301, Setting is the direction vector on the central axis of the roller, C(x0,y0,z0) is the point on the central axis of the cylinder, and P(x,y,z) is an arbitrary point on the circumferential surface of the roller; S302. The vertical distance L from point P (x, y, z) to point C on the central axis of the roller is equal to the actual radius r of the cylinder, then: L 2 ＝r 2 ； S303, in actual measurement, the error value between the measured position of the measuring point and the actual radius of the cylinder, setting the error value d between the distance L from the measuring point to the central axis of the cylinder and the radius r of the cylinder i , the error value is the difference between the distance L and the cylinder radius r, and the error function is defined as: S304, using the initial radius r of the roller, the coordinates of the center of the roller bottom surface and the direction vector of the cylindrical axis as the initial values, then substituting the data and coordinates of the measuring point P into the error function in turn, performing iterative calculation on the error function to solve the equation parameter values ​​of the fitted cylindrical surface, stopping the iterative calculation when the convergence threshold or the number of iterations is met, and obtaining the equation parameter values ​​of the optimal solution, using the equation parameter values ​​of the optimal solution according to the configuration of the cylindrical surface, completing the fitting of the cylindrical surface, and obtaining the coordinate information of the actual clamping position of the roller, wherein the position information of the fitted roller includes the fitting axial direction, the fitting radius and the fitting center axis.

7. The fitting positioning method according to claim 6, characterized in that: In step S304, the Levenberg-Marquardt algorithm is used to iteratively solve the error function, and the initial values ​​used in the iterative calculation are the initial radius r of the roller, the coordinates of the center of the roller bottom surface and the Z-axis direction vector.

8. The fitting positioning method according to claim 1, characterized in that: In step S4, the position information of the fitting roller is obtained, and the center axis of the fitting roller is used as the Z′ axis to establish a three-dimensional fitting coordinate system. The position information of the cylindrical surface is transformed to obtain the coordinate data of the cylindrical surface in the new coordinate system, thereby converting the coordinate data of the original coordinate system into the coordinate data of the new coordinate system.

9. A roller cladding processing method based on the fitting positioning method according to any one of claims 1 to 8, characterized in that: Includes steps: Step 1: Grind and clean the roller surface to remove pollutants on the roller surface; fix the roller on the turntable using a three-jaw chuck and a rotary ejector pin; Step 2: Use a measuring tool to measure the surface of the roller circumference to obtain coordinate data of the measuring points, and perform fitting and coordinate conversion of the roller cylindrical surface by the measuring method according to the obtained coordinate data of the measuring points to obtain coordinate information of the actual clamping position; Step 3: According to the coordinate information of the actual clamping position, use the path planning software to plan the motion trajectory and generate the code of the path corresponding to the cladding pattern; Step 4: Input the code into the cladding machine and perform cladding on the roller with the corresponding knife line pattern.

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