A laser cutting rotation center calibration method and system

Abstract

This invention relates to a laser cutting rotation center calibration method and system, comprising: acquiring several cutting surfaces at different angles of a pipe to be cut; for any cutting surface of the pipe, when the cutting surface is directly above the rotation center, acquiring the corresponding rotation angle of the cutting surface, and acquiring several follow-up heights of the cutting surface based on a preset acquisition strategy, thereby obtaining the corresponding cutting surface height; based on all the rotation angles of the cutting surfaces, pairing all the cutting surfaces according to a preset pairing rule to obtain a pairing result; calculating a first direction compensation value and a second direction compensation value based on the pairing result and all the cutting surface heights to obtain the rotation center offset; and calibrating the rotation center based on the rotation center offset. Compared with the prior art, this invention only acquires the follow-up height of a single point on the cutting surface as the cutting surface height, which can more comprehensively reflect the geometric characteristics of the pipe, thereby improving the accuracy of laser cutting rotation center calibration.

Description

Technical Field

[0001] This invention relates to the field of laser cutting technology, and in particular to a laser cutting rotation center calibration method and system. Background Technology

[0002] Currently, in the field of laser cutting technology, it is essential to ensure that the geometric center of the processed tube is precisely aligned with the rotation center during cutting to achieve accurate cutting. However, in actual processing, because the processed tube is not a perfect geometry, its structure may be deformed, and its dimensions may have unavoidable minor errors. This often results in the actual geometric center of the processed tube not being precisely aligned with the rotation center during cutting. To address this, the mainstream technology in this field currently employs a "four-point centering" method. This method estimates the geometric center by measuring the follow-up height of four cutting points at four rotational angles of the processed tube, and then adjusts the rotation center based on the estimation results.

[0003] Although the current "four-point centering" method can achieve a certain degree of calibration of the rotation center of the processed pipe, the cut surface of the processed pipe is not a perfect plane and has a certain degree of irregular deformation. This causes fluctuations in the follow-up height at different positions on the same cut surface, resulting in inaccurate estimation of the geometric center of the processed pipe by the "four-point centering" method. Furthermore, the cutting height adjuster may not have fully entered a stable working state during the initial start-up of the "four-point centering" process, and the follow-up height it collects may contain errors. Summary of the Invention

[0004] The present invention aims to provide a laser cutting rotation center calibration method and system to solve the above-mentioned technical problems and thereby improve the accuracy of rotation center calibration.

[0005] To achieve the above objectives, the first aspect of the present invention provides a laser cutting rotation center calibration method, comprising the following steps: acquiring several cutting surfaces at different angles of a pipe to be cut; for any cutting surface of the pipe, when the cutting surface is directly above the rotation center, acquiring the corresponding cutting surface rotation angle, and acquiring several follow-up heights of the cutting surface based on a preset acquisition strategy, thereby obtaining the corresponding cutting surface height; based on all the cutting surface rotation angles, pairing all the cutting surfaces according to a preset pairing rule to obtain a pairing result; calculating a first direction compensation value and a second direction compensation value based on the pairing result and all the cutting surface heights to obtain a rotation center offset; and calibrating the rotation center based on the rotation center offset.

[0006] The aforementioned laser cutting rotation center calibration method calculates the cutting surface height by acquiring the follow-up height at multiple positions on the cutting surface. Compared to existing technologies that only acquire the follow-up height of a single point on the cutting surface, this method more comprehensively reflects the geometric characteristics of the pipe cutting surface, improves the representativeness of the obtained cutting surface height, and reduces the cutting surface height error caused by irregular deformation of the cutting surface, thereby improving the accuracy of subsequent rotation center calibration. Furthermore, acquiring follow-up height data at multiple positions on the cutting surface reduces the impact of inaccurate data collected during the initial startup of the cutting height adjuster, before it has fully entered a stable working state, on the rotation center calibration, further improving the accuracy of laser cutting rotation center calibration.

[0007] In one possible implementation, for any cut surface of the pipe, when the cut surface is directly above the rotation center, the rotation angle of the cut surface corresponding to the cut surface is obtained, and several follow-up heights of the cut surface are obtained based on a preset acquisition strategy, thereby obtaining the cut surface height corresponding to the cut surface. This includes: obtaining reference coordinates and acquisition step distance; obtaining several acquisition points based on the reference coordinates and acquisition step distance; for any acquisition point, obtaining the follow-up height of the acquisition point, and then obtaining several corresponding follow-up heights based on the several acquisition points; calculating a weighted average based on the several follow-up heights to obtain the cut surface height corresponding to the cut surface.

[0008] In this implementation, the reference coordinates of the cutting surface are used as the starting point. According to the length interval of the acquisition step, several acquisition points with equal intervals are acquired on the cutting surface. This ensures that the acquisition points can be evenly distributed on the cutting surface, so that the acquired follow-up heights can reflect the fluctuation heights at various points on the cutting surface and accurately reflect the irregular deformation of the cutting surface, thereby improving the accuracy of subsequent laser cutting rotation center calibration.

[0009] In one possible implementation, the step of calculating a weighted average based on several moving heights to obtain the cutting surface height corresponding to the cutting surface includes: obtaining the cross-section of the pipe, and then obtaining the corresponding cutting surface length based on the cross-section; obtaining the midpoint of the corresponding cutting surface based on the reference coordinates and the cutting surface length; for any moving height, calculating the distance between the acquisition point corresponding to the moving height and the midpoint of the cutting surface to obtain the moving height weight corresponding to the moving height, and then obtaining several moving height weights based on several moving heights; and calculating a weighted average based on several moving heights and the corresponding several moving height weights to obtain the cutting surface height corresponding to the cutting surface.

[0010] In this implementation, the tracking height corresponding to the acquisition point is weighted according to the distance between the acquisition point and the midpoint of the cutting surface. Specifically, the closer the acquisition point is to the midpoint of the cutting surface, the higher the weight of the tracking height corresponding to the acquisition point; the farther the acquisition point is from the midpoint of the cutting surface, the lower the weight of the tracking height corresponding to the acquisition point. This implementation assigns a higher weight to the tracking height data closer to the midpoint, making the obtained cutting surface height data closer to the true geometric center height of the cutting surface, improving the accuracy of the calculation of the true geometric center of the pipe in this invention, thereby improving the accuracy of subsequent laser cutting rotation center calibration.

[0011] In one possible implementation, for any given follow-up height, the distance between the acquisition point corresponding to that follow-up height and the midpoint of the cutting surface is calculated to obtain the follow-up height weight corresponding to that follow-up height. Then, based on several follow-up heights, several corresponding follow-up height weights are obtained, and the calculation formula is expressed as follows:

[0012]

[0013] Among them, w i The following represents the weight of the following height corresponding to the i-th following height, the position i represents the acquisition point corresponding to the i-th following height, and L / 2 represents the midpoint of the cutting surface.

[0014] In this implementation, L represents the length of the cutting surface, and L / 2 represents the midpoint of the cutting surface. The above calculation formula converts the absolute value of the distance between the acquisition point and the midpoint of the cutting surface into a weighting coefficient, thereby assigning higher weight to the motion height data closer to the midpoint.

[0015] In one possible implementation, the step of pairing all the cutting surfaces according to a preset pairing rule based on the rotation angle of all the cutting surfaces to obtain a pairing result includes: for any two cutting surfaces, calculating the difference in the rotation angle of the corresponding cutting surfaces; pairing the cutting surfaces whose difference in the rotation angle of the cutting surfaces is within the range of 180°±Δ to obtain a first cutting surface group and a second cutting surface group, and then using the first cutting surface group and the second cutting surface group as the pairing result, where Δ represents a preset angle tolerance.

[0016] It should be noted that, for any two cutting surfaces, the difference in the rotation angle of the corresponding cutting surfaces is calculated; cutting surfaces whose rotation angle difference is within the range of 180°±Δ are paired to obtain a first cutting surface group and a second cutting surface group, which is equivalent to pairing two surfaces of the pipe that are directly opposite each other. Specifically, when the rotation angle is 0°, the cutting surface located directly above the rotation center is defined as the first surface; when the rotation angle is 90°, the cutting surface located directly above the rotation center is defined as the second surface; when the rotation angle is 180°, the cutting surface located directly above the rotation center is defined as the third surface; and when the rotation angle is 270°, the cutting surface located directly above the rotation center is defined as the fourth surface. The above technical implementation is equivalent to pairing the first surface and the third surface to obtain the first cutting surface group, and pairing the second surface and the fourth surface to obtain the second cutting surface group. Furthermore, considering the potential errors in the rotation angle during actual measurement and testing, the difference in rotation angle between two directly opposite cutting surfaces may not be exactly 180°. Therefore, an angle tolerance is preset to ensure that the difference in rotation angle between the two cutting surfaces has a certain allowable range of angle deviation.

[0017] In one possible implementation, the step of calculating the first direction compensation value and the second direction compensation value based on the pairing result and all the heights of the cut surfaces to obtain the rotation center offset includes: calculating the difference in the heights of the cut surfaces in the first cut surface group to obtain the first direction compensation value; and calculating the difference in the heights of the cut surfaces in the second cut surface group to obtain the second direction compensation value.

[0018] In this implementation, the rotation center compensation value of the pipe in this direction is obtained by calculating the height difference between two cutting surfaces located in opposite positions. Then, the rotation center compensation values ​​of the pipe in two directions are obtained based on the two sets of opposite cutting surfaces. The rotation center of the pipe can be calibrated based on the rotation center compensation values ​​in the two directions, thereby improving the accuracy of rotation center calibration.

[0019] In one possible implementation, for any cut surface of the pipe, when the cut surface is directly above the rotation center, obtaining the rotation angle of the cut surface corresponding to the cut surface, and obtaining several follow-up heights of the cut surface based on a preset acquisition strategy, includes: for any cut surface of the pipe, when the cut surface is directly above the rotation center, obtaining the rotation angle of the cut surface corresponding to the cut surface, and obtaining several original follow-up heights of the cut surface based on a preset acquisition strategy; and performing dynamic smoothing processing on the several original follow-up heights based on a moving average method to obtain several follow-up heights.

[0020] In this implementation, by dynamically smoothing the original follow-up height data, the data fluctuation of the original follow-up height data is reduced and the accuracy of the follow-up height data is improved. This solves the problem of data fluctuation caused by the unstable start-up of the cutting head during the follow-up process, which does not fully enter a stable working state, and improves the accuracy of the rotation center calibration.

[0021] A second aspect of the present invention provides a laser cutting rotation center calibration system, comprising a cutting module, a height calculation module, an angle pairing module, and a rotation center calibration module, wherein: the cutting module is used to acquire several cutting surfaces at different angles of the pipe to be cut; the height calculation module is used to acquire several follow-up heights of any cutting surface of the pipe when the cutting surface is directly above the rotation center, based on a preset acquisition strategy, thereby obtaining the corresponding cutting surface height; the angle pairing module is used to acquire the corresponding cutting surface rotation angle of any cutting surface of the pipe when the cutting surface is directly above the rotation center, and then pair all the cutting surfaces according to a preset pairing rule based on all the cutting surface rotation angles to obtain a pairing result; the rotation center calibration module is used to calculate a first direction compensation value and a second direction compensation value based on the pairing result and all the cutting surface heights to obtain a rotation center offset, and then calibrate the rotation center based on the rotation center offset.

[0022] In this implementation, the cutting surface height is calculated by acquiring the follow-up heights at multiple locations on the cutting surface. Compared to existing technologies that only acquire the follow-up height of a single point on the cutting surface, this method more comprehensively reflects the geometric characteristics of the pipe cutting surface, improves the representativeness of the obtained cutting surface height, and reduces the cutting surface height error caused by irregular deformation of the cutting surface, thereby improving the accuracy of subsequent rotation center calibration. Furthermore, acquiring follow-up height data at multiple locations on the cutting surface reduces the impact of inaccurate data collected during the initial startup of the cutting height adjuster, before it has fully entered a stable working state, on the rotation center calibration, thus improving the accuracy of laser cutting rotation center calibration.

[0023] In one possible implementation, in the height calculation module, for any cut surface of the pipe, when the cut surface is directly above the rotation center, several follow-up heights of the cut surface are obtained based on a preset acquisition strategy to obtain the corresponding cut surface height. This includes: acquiring reference coordinates and acquisition step distance; acquiring several acquisition points based on the reference coordinates and acquisition step distance; for any acquisition point, acquiring the follow-up height of that acquisition point, and then acquiring several corresponding follow-up heights based on the several acquisition points; and calculating a weighted average based on the several follow-up heights to obtain the corresponding cut surface height.

[0024] In this implementation, the reference coordinates of the cutting surface are used as the starting point. According to the length interval of the acquisition step, several acquisition points with equal intervals are acquired on the cutting surface. This ensures that the acquisition points can be evenly distributed on the cutting surface, so that the acquired follow-up heights can reflect the fluctuation heights at various points on the cutting surface and accurately reflect the irregular deformation of the cutting surface, thereby improving the accuracy of subsequent laser cutting rotation center calibration.

[0025] In one possible implementation, in the height calculation module, the step of calculating a weighted average based on several moving heights to obtain the height of the cutting surface corresponding to the cutting surface includes: obtaining the cross-section of the pipe, and then obtaining the corresponding cutting surface length based on the cross-section; obtaining the midpoint of the corresponding cutting surface based on the reference coordinates and the cutting surface length; for any moving height, calculating the distance between the acquisition point corresponding to the moving height and the midpoint of the cutting surface, obtaining the moving height weight corresponding to the moving height, and then obtaining several moving height weights based on several moving heights; and calculating a weighted average based on several moving heights and the corresponding several moving height weights to obtain the height of the cutting surface corresponding to the cutting surface.

[0026] In this implementation, the tracking height corresponding to the acquisition point is weighted according to the distance between the acquisition point and the midpoint of the cutting surface. Specifically, the closer the acquisition point is to the midpoint of the cutting surface, the higher the weight of the tracking height corresponding to the acquisition point; the farther the acquisition point is from the midpoint of the cutting surface, the lower the weight of the tracking height corresponding to the acquisition point. This implementation assigns a higher weight to the tracking height data closer to the midpoint, making the obtained cutting surface height data closer to the true geometric center height of the cutting surface, improving the accuracy of the calculation of the true geometric center of the pipe in this invention, thereby improving the accuracy of subsequent laser cutting rotation center calibration. Attached Figure Description

[0027] Figure 1 This is a schematic flowchart of a laser cutting rotation center calibration method provided in an embodiment of the present invention;

[0028] Figure 2 This is a perspective view of a pipe provided in an embodiment of the present invention;

[0029] Figure 3 This is a front view of a pipe provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of a laser cutting rotation center calibration system provided in an embodiment of the present invention;

[0031] Wherein: 11, First face; 111, Midpoint of cutting face; 12, Second face; 2, Section; 100, Cutting module; 200, Height calculation module; 300, Angle matching module; 400, Rotation center calibration module. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0033] The following detailed descriptions are exemplary and intended to provide further detailed explanation of the invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings are used to distinguish different objects and not to describe a particular order.

[0034] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] Before describing this application in detail with reference to the accompanying drawings and embodiments, the terms and application scenarios involved in this application will first be explained.

[0037] In the current field of laser cutting, to ensure cutting accuracy, the geometric center of the processed tube must be precisely aligned with the rotation center of the fixture. However, in actual operation, factors such as slight deformation of the tube surface and dimensional deviations during tube production often prevent the geometric center and rotation center from coinciding. To address this, current mainstream technology employs a "four-point centering" method. This method measures the height of four acquisition points corresponding to rotation angles of 0°, 90°, 180°, and 270°, calculating the offset compensation value between the geometric center and rotation center. While the current "four-point centering" method can achieve a certain degree of rotation center calibration, the cutting surface of the processed tube is not a perfect plane and exhibits irregular deformation. This causes fluctuations in the height of the acquisition points at different positions on the same cutting surface, resulting in inaccurate estimations of the geometric center of the processed tube using the "four-point centering" method. Furthermore, the cutting height adjuster may not fully stabilize during the initial startup of the "four-point centering" process, potentially leading to errors in the acquired height.

[0038] To solve the above technical problems, see Figure 1 This invention provides a laser cutting rotation center calibration method, comprising the following steps:

[0039] S101. Obtain several cutting surfaces at different angles of the pipe to be cut; specifically, in this embodiment, obtain the cutting surfaces of the rectangular pipe to be cut at four angles.

[0040] S102. For any cut surface of the pipe, when the cut surface is directly above the rotation center, the rotation angle of the cut surface corresponding to the cut surface is obtained, and several follow-up heights of the cut surface are obtained based on a preset acquisition strategy, thereby obtaining the cut surface height corresponding to the cut surface; specifically, in this embodiment, after obtaining several follow-up heights of the cut surface, the several follow-up heights are stored in the array H corresponding to the cut surface. n In the middle; where n represents the nth cutting surface of the pipe to be cut.

[0041] S103. Based on the rotation angle of all the cutting surfaces, pair all the cutting surfaces according to the preset pairing rules to obtain the pairing result;

[0042] S104. Calculate the first direction compensation value and the second direction compensation value based on the pairing result and the height of all the cut surfaces to obtain the rotation center offset; specifically, in this embodiment, the first direction is the horizontal direction of the pipe, and the second direction is the vertical direction of the pipe.

[0043] S105. The rotation center is calibrated based on the rotation center offset.

[0044] The aforementioned laser cutting rotation center calibration method calculates the cutting surface height by acquiring the follow-up height at multiple positions on the cutting surface. Compared to existing technologies that only acquire the follow-up height of a single point on the cutting surface, this method more comprehensively reflects the geometric characteristics of the pipe cutting surface, improves the representativeness of the obtained cutting surface height, and reduces the cutting surface height error caused by irregular deformation of the cutting surface, thereby improving the accuracy of subsequent rotation center calibration. Furthermore, acquiring follow-up height data at multiple positions on the cutting surface reduces the impact of inaccurate data collected during the initial startup of the cutting height adjuster, before it has fully entered a stable working state, on the rotation center calibration, further improving the accuracy of laser cutting rotation center calibration.

[0045] In one possible embodiment, for any cut surface of the pipe, when the cut surface is directly above the rotation center, the rotation angle of the cut surface corresponding to the cut surface is obtained, and several follow-up heights of the cut surface are obtained based on a preset acquisition strategy, thereby obtaining the cut surface height corresponding to the cut surface. This includes: obtaining reference coordinates and acquisition step distance; obtaining several acquisition points based on the reference coordinates and acquisition step distance; for any acquisition point, obtaining the follow-up height of the acquisition point, and then obtaining several corresponding follow-up heights based on the several acquisition points; calculating a weighted average based on the several follow-up heights to obtain the cut surface height corresponding to the cut surface.

[0046] Specifically, in practical applications, the width of the pipe to be cut is usually no more than 550mm. Therefore, for a pipe with a width of 550mm to be cut, the acquisition step distance can be set to 5.5mm, and 100 acquisition points can be obtained on the cutting surface based on this acquisition step distance.

[0047] In this embodiment, taking the reference coordinates of the cutting surface as the starting point, several acquisition points with equal intervals between each other are acquired on the cutting surface according to the length interval of the acquisition step. This ensures that the acquisition points can be evenly distributed on the cutting surface, so that the acquired follow-up heights can reflect the fluctuation heights at various points on the cutting surface and accurately reflect the irregular deformation of the cutting surface, thereby improving the accuracy of subsequent laser cutting rotation center calibration.

[0048] See Figure 2 and Figure 3In one possible embodiment, the step of calculating a weighted average based on several moving heights to obtain the cutting surface height corresponding to the cutting surface includes: obtaining the cross-section 2 of the pipe, and then obtaining the corresponding cutting surface length based on the cross-section 2; obtaining the midpoint 111 of the corresponding cutting surface based on the reference coordinates and the cutting surface length; for any moving height, calculating the distance between the acquisition point corresponding to the moving height and the midpoint 111 of the cutting surface, obtaining the moving height weight corresponding to the moving height, and then obtaining several moving height weights based on several moving heights; calculating a weighted average based on several moving heights and the corresponding several moving height weights to obtain the cutting surface height corresponding to the cutting surface.

[0049] Specifically, the weighted average value calculated based on several follow-up heights to obtain the cutting surface height corresponding to the cutting surface can be expressed as the following formula 1:

[0050]

[0051] Among them, Z 中点 h represents the height of the cut surface. c,i w represents the i-th follower height of the c-th cutting surface. i The weight of the i-th follower height is represented by k, and k represents the total number of follower heights collected on the c-th cutting surface.

[0052] In this embodiment, the tracking height corresponding to the acquisition point is weighted according to the distance between the acquisition point and the midpoint 111 of the cutting surface. Specifically, the closer the acquisition point is to the midpoint 111 of the cutting surface, the higher the weight of the tracking height corresponding to the acquisition point; the farther the acquisition point is from the midpoint 111 of the cutting surface, the lower the weight of the tracking height corresponding to the acquisition point. This embodiment assigns a higher weight to the tracking height data closer to the midpoint, making the obtained cutting surface height data closer to the true geometric center height of the cutting surface, improving the accuracy of the present invention in calculating the true geometric center of the pipe, thereby improving the accuracy of subsequent laser cutting rotation center calibration.

[0053] See Figure 2 and Figure 3 In one possible embodiment, for any given follow-up height, the distance between the acquisition point corresponding to that follow-up height and the midpoint 111 of the cutting surface is calculated to obtain the follow-up height weight corresponding to that follow-up height. Then, based on several follow-up heights, several corresponding follow-up height weights are obtained, and the calculation formula is expressed as follows:

[0054]

[0055] Among them, w iThe following represents the weight of the following height corresponding to the i-th following height, the position i represents the acquisition point corresponding to the i-th following height, L / 2 represents the midpoint 111 of the cutting surface, and L represents the width of the first surface 11 corresponding to the section 2.

[0056] In this embodiment, L represents the length of the cutting surface, and L / 2 represents the midpoint 111 of the cutting surface. The above calculation formula converts the absolute value of the distance between the acquisition point and the midpoint 111 of the cutting surface into a weighting coefficient, thereby assigning higher weight to the motion height data closer to the midpoint.

[0057] In one possible embodiment, the step of pairing all the cutting surfaces according to a preset pairing rule based on the rotation angle of all the cutting surfaces to obtain a pairing result includes: for any two cutting surfaces, calculating the difference in the rotation angle of the corresponding cutting surfaces; pairing the cutting surfaces whose difference in the rotation angle of the cutting surfaces is within the range of 180°±Δ to obtain a first cutting surface group and a second cutting surface group, and then using the first cutting surface group and the second cutting surface group as the pairing result, wherein Δ represents a preset angle tolerance.

[0058] See Figure 2 It should be noted that, for any two cutting surfaces, the difference in the rotation angle of the corresponding cutting surfaces is calculated; cutting surfaces whose rotation angle difference is within the range of 180°±Δ are paired to obtain a first cutting surface group and a second cutting surface group, which is equivalent to pairing two surfaces of the pipe that are directly opposite each other. Specifically, when the rotation angle is 0°, the cutting surface located directly above the rotation center is defined as the first surface 11; when the rotation angle is 90°, the cutting surface located directly above the rotation center is defined as the second surface 12; when the rotation angle is 180°, the cutting surface located directly above the rotation center is defined as the third surface; and when the rotation angle is 270°, the cutting surface located directly above the rotation center is defined as the fourth surface. The above technical implementation is equivalent to pairing the first surface and the third surface to obtain the first cutting surface group, and pairing the second surface and the fourth surface to obtain the second cutting surface group. Furthermore, considering the potential errors in rotation angle during actual measurement and testing, the difference in rotation angle between two directly opposite cutting surfaces may not be exactly 180°. Therefore, an angle tolerance is preset to ensure that the difference in rotation angle between the two cutting surfaces has a certain allowable range of angle deviation. Specifically, Figure 2 The first side 11 and the second side 12 are shown. The third and fourth sides are not shown. Figure 2 As shown in the diagram, it should be understood that the third surface is actually the cutting surface in the direction directly opposite to the first cutting surface 11, and the fourth surface is actually the cutting surface in the direction directly opposite to the second cutting surface 12.

[0059] In one possible embodiment, the step of calculating the first direction compensation value and the second direction compensation value based on the pairing result and all the heights of the cut surfaces to obtain the rotation center offset includes: calculating the difference in the heights of the cut surfaces in the first cut surface group to obtain the first direction compensation value; and calculating the difference in the heights of the cut surfaces in the second cut surface group to obtain the second direction compensation value.

[0060] Specifically, the first direction is the horizontal direction of the pipe, and the second direction is the vertical direction of the pipe. The calculation of the difference in the height of the cutting surfaces in the first cutting surface group, and thus obtaining the compensation value for the first direction, can be expressed as the following formula 3:

[0061]

[0062] Among them, Z 90° This indicates the height of the cut surface corresponding to the second face 12 when the rotation angle is 90°; Z 270° This indicates the height of the cutting surface on the fourth face when the rotation angle is 270°;

[0063] The difference in height of the cutting surfaces in the second cutting surface group is calculated to obtain the second directional compensation value, which can be expressed as Equation 4 below:

[0064]

[0065] Among them, Z 0° This indicates the height of the cut surface corresponding to the first face 11 when the rotation angle is 0°; Z 180° This indicates the height of the cut surface on the third face when the rotation angle is 180°.

[0066] In this embodiment, the rotation center compensation value of the pipe in this direction is obtained by calculating the height difference between two cutting surfaces located in opposite positions. Then, the rotation center compensation values ​​of the pipe in two directions are obtained based on the two sets of opposite cutting surfaces. The rotation center of the pipe can be calibrated based on the rotation center compensation values ​​in two directions, thereby improving the accuracy of rotation center calibration.

[0067] In one possible embodiment, for any cut surface of the pipe, when the cut surface is directly above the rotation center, obtaining the rotation angle of the cut surface corresponding to the cut surface, and obtaining several follow-up heights of the cut surface based on a preset acquisition strategy, includes: for any cut surface of the pipe, when the cut surface is directly above the rotation center, obtaining the rotation angle of the cut surface corresponding to the cut surface, and obtaining several original follow-up heights of the cut surface based on a preset acquisition strategy; and performing dynamic smoothing processing on the several original follow-up heights based on a moving average method to obtain several follow-up heights.

[0068] Specifically, the dynamic smoothing of several original follow-up heights based on the moving average method to obtain several follow-up heights can be expressed as Equation 5 below:

[0069]

[0070] Among them, h 平滑 , i represents the i-th moving height of the cut surface, h j The j-th original follower height of the cut surface is represented, and n represents the sliding window size of the dynamic averaging method, which determines how many original follower heights are in the sliding window.

[0071] In this embodiment, by dynamically smoothing the original follow-up height data, the data fluctuation of the original follow-up height data is reduced, and the accuracy of the follow-up height data is improved. This solves the problem of data fluctuation caused by the unstable start-up of the cutting head during the follow-up process, which does not fully enter a stable working state, and improves the accuracy of the rotation center calibration.

[0072] See Figure 4 This invention provides a laser cutting rotation center calibration system, including a cutting module 100, a height calculation module 200, an angle pairing module 300, and a rotation center calibration module 400. The cutting module 100 acquires several cutting surfaces at different angles of the pipe to be cut. The height calculation module 200, for any cutting surface of the pipe, when the cutting surface is directly above the rotation center, acquires several follow-up heights of the cutting surface based on a preset acquisition strategy, thereby obtaining the corresponding cutting surface height. The angle pairing module 300, for any cutting surface of the pipe, when the cutting surface is directly above the rotation center, acquires the corresponding cutting surface rotation angle, and then, based on all the cutting surface rotation angles, pairs all the cutting surfaces according to a preset pairing rule to obtain a pairing result. The rotation center calibration module 400, based on the pairing result and all the cutting surface heights, calculates a first direction compensation value and a second direction compensation value to obtain a rotation center offset, and then calibrates the rotation center based on the rotation center offset.

[0073] In this embodiment, the cutting surface height is calculated by acquiring the follow-up heights at multiple locations on the cutting surface. Compared to the prior art, which only acquires the follow-up height of a single point on the cutting surface, this method more comprehensively reflects the geometric characteristics of the pipe cutting surface, improves the representativeness of the obtained cutting surface height, and reduces the cutting surface height error caused by irregular deformation of the cutting surface, thereby improving the accuracy of subsequent rotation center calibration. Furthermore, acquiring follow-up height data at multiple locations on the cutting surface reduces the impact of inaccurate data collected during the initial startup of the cutting height adjuster, before it has fully entered a stable working state, on the rotation center calibration, thus improving the accuracy of laser cutting rotation center calibration.

[0074] In one possible embodiment, in the height calculation module 200, for any cut surface of the pipe, when the cut surface is directly above the rotation center, several follow-up heights of the cut surface are obtained based on a preset acquisition strategy to obtain the corresponding cut surface height. This includes: acquiring reference coordinates and acquisition step distance; acquiring several acquisition points based on the reference coordinates and acquisition step distance; acquiring the follow-up height of any acquisition point, and then acquiring several corresponding follow-up heights based on the several acquisition points; and calculating a weighted average based on the several follow-up heights to obtain the corresponding cut surface height.

[0075] In this embodiment, taking the reference coordinates of the cutting surface as the starting point, several acquisition points with equal intervals between each other are acquired on the cutting surface according to the length interval of the acquisition step. This ensures that the acquisition points can be evenly distributed on the cutting surface, so that the acquired follow-up heights can reflect the fluctuation heights at various points on the cutting surface and accurately reflect the irregular deformation of the cutting surface, thereby improving the accuracy of subsequent laser cutting rotation center calibration.

[0076] In one possible embodiment, in the height calculation module 200, the step of calculating a weighted average based on several moving heights to obtain the height of the cutting surface corresponding to the cutting surface includes: obtaining the cross-section 2 of the pipe, and then obtaining the corresponding cutting surface length based on the cross-section 2; obtaining the midpoint 111 of the corresponding cutting surface based on the reference coordinates and the cutting surface length; for any moving height, calculating the distance between the acquisition point corresponding to the moving height and the midpoint 111 of the cutting surface, obtaining the moving height weight corresponding to the moving height, and then obtaining several moving height weights based on several moving heights; and calculating a weighted average based on several moving heights and the corresponding several moving height weights to obtain the height of the cutting surface corresponding to the cutting surface.

[0077] In this embodiment, the tracking height corresponding to the acquisition point is weighted according to the distance between the acquisition point and the midpoint 111 of the cutting surface. Specifically, the closer the acquisition point is to the midpoint 111 of the cutting surface, the higher the weight of the tracking height corresponding to the acquisition point; the farther the acquisition point is from the midpoint 111 of the cutting surface, the lower the weight of the tracking height corresponding to the acquisition point. This embodiment assigns a higher weight to the tracking height data closer to the midpoint, making the obtained cutting surface height data closer to the true geometric center height of the cutting surface, improving the accuracy of the present invention in calculating the true geometric center of the pipe, thereby improving the accuracy of subsequent laser cutting rotation center calibration.

[0078] This invention provides another method for calibrating the rotation center of laser cutting, comprising the following steps:

[0079] S201. Define the chuck center as O, and the actual rotation center of the pipe to be cut as o. The actual rotation center is offset from the chuck center. Taking the chuck center as the origin, the offset includes the vertical Z-direction offset Z0. ex and the horizontal Y-direction offset Y ex .

[0080] S202. Obtain several cutting surfaces at different angles of the pipe to be cut; specifically, in this embodiment, obtain the cutting surfaces of the rectangular pipe to be cut at four angles.

[0081] S203. For any cut surface of the pipe, when the cut surface is directly above the rotation center, obtain the rotation angle of the cut surface corresponding to the cut surface, and obtain several follow-up heights of the cut surface based on a preset acquisition strategy; specifically, in this embodiment, after obtaining several follow-up heights of the cut surface, store the several follow-up heights in the array H corresponding to the cut surface. n In the middle; where n represents the nth cutting surface of the pipe to be cut.

[0082] S204. Based on the rotation angle of all the cutting surfaces, pair all the cutting surfaces according to the preset pairing rules to obtain the pairing result; specifically, for any two cutting surfaces, calculate the difference in the rotation angle of the corresponding cutting surfaces; pair the cutting surfaces whose difference in the rotation angle of the cutting surfaces is within the range of 180°±Δ to obtain a first cutting surface group and a second cutting surface group, and then use the first cutting surface group and the second cutting surface group as the pairing result, where Δ represents the preset angle tolerance.

[0083] See Figure 2It should be noted that, for any two cutting surfaces, the difference in the rotation angle of the corresponding cutting surfaces is calculated; cutting surfaces whose rotation angle difference is within the range of 180°±Δ are paired to obtain a first cutting surface group and a second cutting surface group, which is equivalent to pairing two surfaces of the pipe that are directly opposite each other. Specifically, when the rotation angle is 0°, the cutting surface located directly above the rotation center is defined as the first surface 11; when the rotation angle is 90°, the cutting surface located directly above the rotation center is defined as the second surface 12; when the rotation angle is 180°, the cutting surface located directly above the rotation center is defined as the third surface; and when the rotation angle is 270°, the cutting surface located directly above the rotation center is defined as the fourth surface. The above technical implementation is equivalent to pairing the first surface and the third surface to obtain the first cutting surface group, and pairing the second surface and the fourth surface to obtain the second cutting surface group. Furthermore, considering the potential errors in rotation angle during actual measurement and testing, the difference in rotation angle between two directly opposite cutting surfaces may not be exactly 180°. Therefore, an angle tolerance is preset to ensure that the difference in rotation angle between the two cutting surfaces has a certain allowable range of angle deviation. Specifically, Figure 2 The first side 11 and the second side 12 are shown. The third and fourth sides are not shown. Figure 2 As shown in the diagram, it should be understood that the third surface is actually the cutting surface in the direction directly opposite to the first cutting surface 11, and the fourth surface is actually the cutting surface in the direction directly opposite to the second cutting surface 12.

[0084] Specifically, in this embodiment, the Y-axis coordinate y of the cutting head is recorded at the horizontal rotation position of the pipe. When the cutting head enters the cutting state, the initial cutting surface angle θ1 and the initial Y-axis coordinate y1 are recorded, and y1 is used as the reference coordinate of the cutting surface. Subsequently, the follow-up height of all positions on the surface during the cutting process is recorded according to the acquisition strategy and stored in an array.

[0085] The data at this stage is dynamically smoothed. The rotation angle of the cutting surface corresponding to the cutting surface is obtained, and several original follow-up heights of the cutting surface are obtained based on a preset acquisition strategy; the several original follow-up heights are dynamically smoothed based on the moving average method to obtain several follow-up heights.

[0086] Specifically, the dynamic smoothing of several original follow-up heights based on the moving average method to obtain several follow-up heights can be expressed as Equation 5 below:

[0087]

[0088] Among them, h 平滑 , i represents the i-th moving height of the cut surface, h jThe j-th original follower height of the cut surface is represented, and n represents the sliding window size of the dynamic averaging method, which determines how many original follower heights are in the sliding window.

[0089] When the rotation angle reaches θ1+90°, record the angle θ2 of the cutting surface and the initial Y-axis coordinate y2. Use y2 as the reference coordinate, collect the follow-up height of the surface and store it in array H2.

[0090] When the rotation angle reaches θ1+180°, record the angle θ3 of the cutting surface and the initial Y-axis coordinate y3. Use y3 as the reference coordinate, collect the follow-up height of the surface and store it in array H3.

[0091] When the rotation angle reaches θ1+270°, record the angle θ4 of the cutting surface and the initial axis coordinate y4. Use y4 as the reference coordinate, collect the follow-up height of the surface and store it in array H4.

[0092] When the rotation angle reaches θ1+360°, the cutting surface and the cutting surface θ1 are the same physical surface. Record the initial Y-axis coordinate y5 as the reference, collect the follow-up height of this surface and store it in an array.

[0093] It should be noted that, since the cutting head is usually located at the center of the cutting surface in its initial state, in this embodiment, "when the cutting head enters the cutting state, the initial cutting surface angle θ1 and the initial Y-axis coordinate y1 are recorded, and y1 is used as the reference coordinate of the cutting surface. Subsequently, the follow-up height of all positions on the surface during the cutting process is recorded according to the acquisition strategy and stored in an array." Only half of the follow-up height of the cut surface was recorded, while "when the rotation angle reaches θ1+360°, the cut surface and the cut surface θ1 are the same physical surface. The initial Y-axis coordinate y5 is recorded and used as a reference. The follow-up height of this surface is collected and stored in an array." This records the moving height of the other half of the cut surface. In other words, the first surface needs to record the left and right data of the cutting position, which requires an array. and array Record the first face, and finally merge the two arrays to get array H1 as the complete record value of the first face.

[0094] S205. For any cutting surface and its corresponding follower height array, calculate a weighted average based on several follower heights to obtain the cutting surface height corresponding to that cutting surface. Specifically, see... Figure 2 and Figure 3The process involves obtaining the cross-section 2 of the pipe, and then obtaining the corresponding cutting surface length based on the cross-section 2; obtaining the midpoint 111 of the corresponding cutting surface based on the reference coordinates and the cutting surface length; for any given follow-up height, calculating the distance between the acquisition point corresponding to the follow-up height and the midpoint 111 of the cutting surface, obtaining the follow-up height weight corresponding to the follow-up height, and then obtaining several follow-up height weights based on several follow-up heights; and calculating a weighted average based on several follow-up heights and their corresponding follow-up height weights to obtain the cutting surface height corresponding to the cutting surface.

[0095] Specifically, the weighted average value calculated based on several follow-up heights to obtain the cutting surface height corresponding to the cutting surface can be expressed as the following formula 1:

[0096]

[0097] Among them, Z 中点 h represents the height of the cut surface. c,i w represents the i-th follower height of the c-th cutting surface. i The weight of the i-th follower height is represented by k, and k represents the total number of follower heights collected on the c-th cutting surface.

[0098] Furthermore, for any given follow-up height, the distance between the acquisition point corresponding to that follow-up height and the midpoint 111 of the cutting surface is calculated to obtain the follow-up height weight corresponding to that follow-up height. Then, based on several follow-up heights, several corresponding follow-up height weights are obtained, and the calculation formula is expressed as follows: Equation 2:

[0099]

[0100] Among them, w i The following represents the weight of the following height corresponding to the i-th following height, the position i represents the acquisition point corresponding to the i-th following height, L / 2 represents the midpoint 111 of the cutting surface, and L represents the width of the first surface 11 corresponding to the section 2.

[0101] S206. Based on the pairing results and the heights of all the cut surfaces, calculate the first direction compensation value and the second direction compensation value to obtain the rotation center offset. Specifically, in this embodiment, the first direction is the horizontal direction of the pipe, and the second direction is the vertical direction of the pipe. The calculation of the difference in the heights of the cut surfaces in the first cut surface group to obtain the first direction compensation value can be expressed as follows:

[0102] Formula 3:

[0103]

[0104] Among them, Z 90° This indicates the height of the cut surface corresponding to the second face 12 when the rotation angle is 90°; Z 270° This indicates the height of the cutting surface on the fourth face when the rotation angle is 270°;

[0105] The difference in height of the cutting surfaces in the second cutting surface group is calculated to obtain the second directional compensation value, which can be expressed as Equation 4 below:

[0106]

[0107] Among them, Z 0° This indicates the height of the cut surface corresponding to the first face 11 when the rotation angle is 0°; Z 180° This indicates the height of the cut surface on the third face when the rotation angle is 180°.

[0108] S207. The rotation center is calibrated based on the first direction compensation value and the second direction compensation value.

[0109] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0110] 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.

[0111] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the concept of this application, and these improvements and substitutions should also be considered within the scope of protection of this invention. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method for calibrating the rotation center of a laser cutting process, characterized in that, The method comprises the following steps: acquiring a plurality of different angle cutting surfaces of a pipe to be cut; for any cutting surface of the pipe, when the cutting surface is located directly above the rotation center, acquiring a cutting surface rotation angle corresponding to the cutting surface, and based on a preset acquisition strategy, acquiring a plurality of follow-up heights of the cutting surface, and then acquiring a cutting surface height corresponding to the cutting surface, including: acquiring a reference coordinate and an acquisition step distance; based on the reference coordinate and the acquisition step distance, acquiring a plurality of acquisition points; for any acquisition point, acquiring the follow-up height of the acquisition point, and then based on a plurality of acquisition points, acquiring a plurality of follow-up heights corresponding thereto; acquiring a cross section of the pipe, and then based on the cross section, acquiring a corresponding cutting surface length; based on the reference coordinate and the cutting surface length, acquiring a corresponding cutting surface midpoint; for any follow-up height, calculating the distance between the acquisition point corresponding to the follow-up height and the cutting surface midpoint, obtaining the follow-up height weight corresponding to the follow-up height, and then based on a plurality of follow-up heights, obtaining a plurality of follow-up height weights corresponding thereto; based on a plurality of follow-up heights and a plurality of follow-up height weights corresponding thereto, calculating a weighted average value to obtain the cutting surface height corresponding to the cutting surface; The calculation of the weighted average value based on a plurality of follow-up heights and a plurality of follow-up height weights corresponding thereto to obtain the cutting surface height corresponding to the cutting surface can be expressed as: wherein, represents the cutting surface height, represents the ith follower height of the cth cutting surface, represents the follower height weight corresponding to the ith follower height, k represents the total number of follower heights collected on the cth cutting surface; based on all the cutting surface rotation angles, pairing all the cutting surfaces according to a preset pairing rule to obtain a pairing result; based on the pairing result and all the cutting surface heights, calculating a first direction compensation value and a second direction compensation value to obtain a rotation center offset; based on the rotation center offset, calibrating the rotation center.

2. The method of claim 1, wherein, For any follow-up height, the distance between the acquisition point corresponding to the follow-up height and the cutting surface midpoint is calculated to obtain the follow-up height weight corresponding to the follow-up height, and then based on a plurality of follow-up heights, a plurality of follow-up height weights corresponding thereto are obtained, and the calculation formula is as follows: ； wherein, represents the i-th said following height corresponding said following height weight, position i represents the i-th said following height corresponding said collection point, represents the midpoint of said cut surface.

3. The method of claim 1, wherein, based on all the cutting surface rotation angles, pairing all the cutting surfaces according to a preset pairing rule to obtain a pairing result, including: for any two cutting surfaces, calculating the difference value of the corresponding cutting surface rotation angle; cutting surfaces with a difference value of the cutting surface rotation angle within the range of 180°±Δ are paired to obtain a first cutting surface group and a second cutting surface group, and then the first cutting surface group and the second cutting surface group are taken as the pairing result, wherein Δ represents a preset angle tolerance.

4. The method of claim 3, wherein, based on the pairing result and all the cutting surface heights, calculating a first direction compensation value and a second direction compensation value to obtain a rotation center offset, including: calculating the difference value of the cutting surface height in the first cutting surface group, and then obtaining the first direction compensation value; calculating the difference value of the cutting surface height in the second cutting surface group, and then obtaining the second direction compensation value.

5. The method of claim 1, wherein, For any cutting surface of the pipe, when the cutting surface is located directly above the rotation center, a cutting surface rotation angle corresponding to the cutting surface is obtained, and a plurality of follow-up heights of the cutting surface are obtained based on a preset acquisition strategy, including: For any cutting surface of the pipe, when the cutting surface is located directly above the rotation center, a cutting surface rotation angle corresponding to the cutting surface is obtained, and a plurality of follow-up heights of the cutting surface are obtained based on a preset acquisition strategy, including: The plurality of original follow-up heights are dynamically smoothed based on a moving average method to obtain the plurality of follow-up heights.

6. A laser cutting center of rotation calibration system, characterized by, The cutting module, the height calculation module, the angle pairing module, and the rotation center calibration module are included, wherein: The cutting module is configured to obtain a plurality of cutting surfaces of the pipe at different angles; The height calculation module is configured to, for any cutting surface of the pipe, when the cutting surface is located directly above the rotation center, obtain a plurality of follow-up heights of the cutting surface based on a preset acquisition strategy, and further obtain a cutting surface height corresponding to the cutting surface, including: obtaining a reference coordinate and an acquisition step distance; based on the reference coordinate and the acquisition step distance, obtaining a plurality of acquisition points; for any acquisition point, obtaining the follow-up height of the acquisition point, and further obtaining a plurality of follow-up heights corresponding to the acquisition points based on the plurality of acquisition points; obtaining a cross section of the pipe, and further obtaining a corresponding cutting surface length based on the cross section; based on the reference coordinate and the cutting surface length, obtaining a corresponding cutting surface midpoint; for any follow-up height, calculating a distance between the acquisition point corresponding to the follow-up height and the cutting surface midpoint to obtain a follow-up height weight corresponding to the follow-up height, and further obtaining a plurality of follow-up height weights corresponding to the plurality of follow-up heights based on the plurality of follow-up heights; calculating a weighted average value based on the plurality of follow-up heights and the plurality of follow-up height weights corresponding to the plurality of follow-up heights to obtain the cutting surface height corresponding to the cutting surface; The cutting surface height corresponding to the cutting surface can be represented as: wherein, represents the cutting surface height, represents the ith follower height of the cth cutting surface, represents the follower height weight corresponding to the ith follower height, k represents the total number of follower heights collected on the cth cutting surface; The angle pairing module is configured to, for any cutting surface of the pipe, when the cutting surface is located directly above the rotation center, obtain a cutting surface rotation angle corresponding to the cutting surface, and further pair all the cutting surfaces according to a preset pairing rule based on all the cutting surface rotation angles to obtain a pairing result; The rotation center calibration module is configured to calculate a first direction compensation value and a second direction compensation value based on the pairing result and all the cutting surface heights to obtain a rotation center offset, and further calibrate the rotation center based on the rotation center offset.

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