A laser processing system and a calibration and trajectory control method thereof

Abstract

The application relates to the technical field of laser processing systems, in particular to a laser processing system and a calibration and track control method thereof. The laser processing system and the calibration and track control method thereof comprise the following steps: generating a digital control track file through track programming software; performing integrated calibration and compensation on straight axes, marble platform perpendicularity, rotating axes and light paths and the like of the system, and establishing a high-precision spatial mapping relationship; analyzing the track file and combining compensation parameters to perform laser processing on a workpiece three-dimensional surface. Through omnibearing automatic calibration and intelligent track control, the precision, consistency and efficiency of micron-level laser texture processing on a complex curved surface are effectively improved.

Description

Technical Field

[0001] This application relates to the field of laser processing system technology, specifically to a laser processing system and its calibration and trajectory control method. Background Technology

[0002] Laser processing technology has been widely used in the field of mold surface treatment due to its advantages such as high precision, non-contact operation, and good flexibility. Traditional mold surface processing often uses lathe machining or planar laser treatment, but it has the following shortcomings: 1. Poor precision in mold surface processing; 2. Lack of three-dimensional texture on the mold surface.

[0003] For high-precision texture processing on complex three-dimensional curved surfaces, the technical requirements are far higher than those for planar processing. Existing laser processing systems often have pain points, such as: decentralized and independent calibration systems: the calibration of linear axes, rotation axes, optical paths, vision systems, etc., is often performed independently, lacking coordination, resulting in large cumulative errors in overall spatial accuracy; insufficient calibration accuracy: traditional methods are difficult to meet the requirements of micron-level high-precision processing, especially in areas such as the positioning of rotation axis centers, resulting in poor accuracy; and even when calibration data is obtained, there is a lack of an integrated data processing module to automatically and in real-time apply compensation parameters to the processing trajectory, still requiring manual intervention, which is inefficient and inaccurate.

[0004] In summary, existing systems and methods for high-precision texture processing on complex three-dimensional curved surfaces have shortcomings, such as poor precision in processing mold surfaces. There is an urgent need in this field for a method that can perform comprehensive, high-precision, and automated calibration and trajectory control of laser processing systems, which can be intelligently applied to laser three-dimensional processing to achieve three-dimensional processing of surface textures on metal molds such as stainless steel, thus enabling higher-precision surface pattern injection molding equipment to have better molds. Summary of the Invention

[0005] To address the problems of the prior art mentioned in the background section, this application provides a calibration and trajectory control method for a laser processing system. The invention objective and technical solution are as follows: (a) Purpose of the invention The primary objective of this invention is to overcome the shortcomings of the prior art and provide a calibration and trajectory control method for a laser processing system to achieve high-precision and high-consistency three-dimensional texture processing on the surface of workpieces such as metal molds.

[0006] Another objective of this invention is to provide an integrated calibration process that enables comprehensive and high-precision calibration and compensation of linear axes, rotary axes, marble platforms, optical path collimation, and hand-eye coordination.

[0007] Another objective of this invention is to provide an intelligent trajectory generation and execution mechanism that can automatically and seamlessly apply the compensation parameters obtained from calibration to machining control, ensuring accurate reproduction of the machining trajectory in three-dimensional space.

[0008] (II) Technical Solution To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a calibration and trajectory control method for a laser processing system, the scheme of which is as follows: A laser processing system is provided; the components of the laser processing system include a worktable for carrying a workpiece, a laser galvanometer integrated module for outputting a laser beam to act on the workpiece, a CNC worktable, a vision inspection component, and a control module; wherein the worktable, the laser galvanometer integrated module, and the vision inspection component are disposed on the CNC worktable, so that the relative positions of the worktable and the laser galvanometer integrated module, and the relative positions of the worktable and the vision inspection component are adjustable; wherein the control module is electrically connected to the CNC worktable, the laser galvanometer integrated module, and the vision inspection component respectively; The calibration and trajectory control method includes the following steps: S1. Trajectory generation step: Import texture image files and 3D model geometric data of the workpiece into trajectory programming software, set processing parameters including processing layer information and depth settings, and the core algorithm of the software calculates based on the texture information and processing parameters to automatically generate a digital control trajectory file containing processing path and action instructions. S2. Calibration steps: Perform precision calibration and compensation on multiple motion axes and optical paths of the laser processing system to establish a high-precision mapping relationship between the mechanical space and the control module. The calibration steps include linear axis calibration, marble platform verticality compensation, first calibration of the rotation axis, and optical path collimation correction. S3. Execution steps: The digital control trajectory file is transmitted to the laser processing system. The control module parses the trajectory file and drives the CNC worktable to run. Combined with the compensation parameters generated in the calibration step, the laser texture processing operation is performed on the three-dimensional surface of the workpiece.

[0009] In some embodiments, a calibration tool assembly is also provided, the calibration tool assembly including a laser interferometer; the linear axis calibration process is as follows: Align the target linear axis with a laser interferometer; Configure the calibration range, step interval, motion start point, and reciprocating motion parameters in the linear axis calibration software; The laser interferometer is controlled by the linear axis calibration software to automatically acquire the position data of the target linear axis and export the data file; The collected data is processed by selecting positive or negative correction terms based on the direction of motion, and then processed in an append-only manner to generate the accuracy compensation parameters of the target linear axis and update them to the control module of the laser processing system. The laser interferometer was used to verify the accuracy of the compensated axis.

[0010] In some embodiments, in the provided laser processing system, the worktable and the laser galvanometer integrated module are disposed on the CNC worktable so that the worktable can be adjusted relative to the laser galvanometer integrated module along the X-axis, Y-axis and Z-axis directions; the target linear axis in the linear axis calibration process includes one or more of the X-axis, Y-axis and Z-axis directions.

[0011] In some embodiments, a calibration tool assembly is also provided, the calibration tool assembly including a reference ruler and a dial indicator; the process of verticality compensation of the marble platform is as follows: Place, level, and fix the reference ruler on the work platform after completing linear accuracy compensation to establish a spatial angle reference; Enable the serial communication function of the linear axis calibration software and configure the motion parameters; Using a dial indicator in conjunction with a triggering device, set to event-driven mode, measure the two orthogonal directional components of the target linear axis in a plane perpendicular to its nominal direction; Control the single-stroke movement of the CNC worktable and automatically collect the vertical deviation data of the dial indicator at each measurement position; Based on the installation direction and inversion option of the dial indicator, select the corresponding correction item at the measurement position, process the collected deviation data in an append manner, and generate parameters for updating the perpendicularity and angle compensation of the corresponding axis. Under the angular reference established by the reference ruler, the accuracy verification of the corresponding vertical component of the corresponding axis is completed.

[0012] In some embodiments, the provided laser processing system further includes a movable contact probe for measurement with a movable position, and the probe is electrically connected to the control module; the CNC worktable is a five-axis CNC worktable, and the work platform and the laser galvanometer integrated module are disposed on the CNC worktable so that the work platform can be adjusted relative to the laser galvanometer integrated module along the X-axis, Y-axis, and Z-axis, and the work platform can rotate about the rotation axis C parallel to the Z-axis, and the laser galvanometer integrated module can rotate about the rotation axis B parallel to the X-axis; In some embodiments, a calibration tool assembly is also provided, the calibration tool assembly including a calibration ball and a mounting fixture; the process of the first calibration of the rotating shaft is as follows: The calibration ball is fixed on the rotating shaft to be calibrated to verify the repeatability accuracy of the probe assembly; The rotating axis is controlled to rotate in steps at a preset angle, and the worktable is controlled to rotate along the C-axis or the laser galvanometer integrated module is controlled to rotate along the B-axis via a CNC worktable. At multiple measurement layers at different heights, the probe is moved relative to and contacts the calibration sphere to accurately acquire the coordinate data of the center of the calibration sphere; Using the collected multi-layer, multi-angle position data, the rotation center position and / or axis direction of the rotating shaft are analyzed through iterative calculation algorithms, and its repeatability is evaluated. Perform rotation axis parameter calibration calculations, generate the final calibration compensation parameters, and save them; Verify the calibration results by measurement. If the accuracy does not meet the standard, iterate through data acquisition and analysis until the preset accuracy requirement is met.

[0013] In some embodiments, the optical path collimation correction process is as follows: Two different working height positions are set above and below the effective working distance of the laser processing system; The laser processing system is controlled to engrave a mark on the surface of the medium at each of the two height positions; The positional deviation between the two markers is measured to calculate the collimation deviation of the current optical path at different heights and the deflection angle of the beam. Optical correction parameters are generated based on the dynamic calculation of the deviation, and the correction parameters are applied to the control module. After the compensation parameters are loaded, backtracking verification is performed: a reference mark is engraved at the reference height, a second mark is engraved at another feature height, and the actual deviation between the two new marks is measured again to verify the correction effect.

[0014] In some embodiments, the device further includes a movable contact probe for measurement with a movable position, and the probe is electrically connected to the control module; the calibration steps also include hand-eye calibration, switch calibration, and a second calibration of the rotating axis; The hand-eye calibration process is as follows: the laser focal plane reference point is precisely calibrated using a probe, and the probe coordinate system reference point is generated by the linked software; the plate to be engraved is rotated 180° using a high-precision rotary fixture, and double cross marks are engraved on the fixed plane of the plate to be engraved. The deviation of the mark center is eliminated by iterative adjustment, and a visual precision reference point is established; the spatial deviation between the laser reference point and the precision point of the probe is input into the control module of the laser processing system, the spatial deviation between the laser reference point and the visual precision reference point is calculated, and the XYZ three-direction and XY two-direction compensation parameters are applied to complete the mapping between the visual coordinate system and the mechanical coordinate system; The switch calibration process is as follows: the probe calibrates the plane of the spray plate to generate a reference origin; a set of straight line marks containing start and stop delays is engraved on the reference surface, and the deviation between the endpoint and the reference line is quantified by a microscope; The second calibration step of the rotation axis includes a C-axis calibration process and a B-axis calibration process. The C-axis calibration process involves placing the calibration plate above the worktable and engraving ±45° cross marks on the calibration plate 100. The rotation center position is calibrated by the center deviation of the double cross marks. The height of the calibration plate is moved, and verification marks are engraved on planes at different heights to check the center coincidence and confirm the normal accuracy. The B-axis calibration process involves engraving ±45° cross marks on the calibration plate and identifying the normal error through deviation patterns. A grid is engraved on the surface of a standard sphere, and the normal calibration effect is verified by splicing continuity.

[0015] In some embodiments, a whole-machine accuracy verification step is performed after the calibration step; the whole-machine accuracy verification process is as follows: a reference coordinate system is established on the surface of a standard sphere; the laser galvanometer integrated module is controlled to perform texture engraving on the surface of the standard sphere, and the deviation between the endpoint and the reference line is quantified by a microscope.

[0016] In some embodiments, the provided laser processing system further includes a movable probe for contact measurement with movable position, and the probe is electrically connected to the control module; before the execution step, a workpiece coordinate matching step is also included: at least 3 X / Y plane points and at least 4 Z plane points are collected on the working surface by probe pressure sensing to generate a spatial compensation matrix; the collected working reference origin is matched with the digital control trajectory file in real time, and name consistency verification is performed to avoid the risk of manual coordinate offset.

[0017] In a second aspect, the present invention provides a laser processing system for implementing the method described above, comprising: Worktable: Used to support workpieces; Laser galvanometer integrated module: used to output laser beam; CNC worktable: used to adjust the relative position of the worktable and the laser galvanometer integrated module; Probes are used for contact measurements; Visual inspection components for visual inspection; The control module is communicatively connected to the laser galvanometer integrated module, the CNC worktable, the vision inspection component, and the probe component; The control module is configured to: execute the functions of the trajectory programming software to generate the digital control trajectory file; execute the processes of linear axis calibration, marble platform verticality compensation, first calibration of the rotary axis, optical path collimation correction, hand-eye calibration, switch cursor calibration, and second calibration of the rotary axis; and control the CNC worktable to parse and execute the trajectory file.

[0018] Thirdly, the present invention provides a calibration tool assembly for implementing the method described above, characterized in that it comprises: Laser interferometers are used for precise data acquisition on linear axes. A reference ruler and a dial indicator are used to establish spatial angular references and measure perpendicularity deviations. The calibration ball and probe are used for acquiring the center coordinate data of the rotation axis; A standard sphere is used to establish a reference coordinate system on its surface. The control module is communicatively connected to the laser interferometer, dial indicator, and probe. The control module is configured to execute a computer program stored in the memory to implement the calibration method steps.

[0019] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0020] Based on the above, compared with the prior art, the solution of this application has the following beneficial effects: Comprehensive precision improvement: Through an integrated multi-sensor calibration system, all factors affecting processing accuracy (linear positioning, perpendicularity, rotation center, optical path, coordinate system mapping) are fully compensated, improving the overall processing accuracy to the micron level and meeting the needs of high-end three-dimensional texture processing; High degree of automation and intelligence: From data acquisition and calculation to the application of compensation parameters, the entire process is highly automated, which greatly reduces the reliance on manual experience and human intervention, improves efficiency, and reduces the error rate.

[0021] True 3D machining capability: It solves the industry challenge of high-precision machining on complex 3D curved surfaces, especially by ensuring a high degree of consistency between the laser path and the 3D model through calibration steps such as rotation axis calibration and hand-eye calibration.

[0022] Excellent repeatability and consistency: The comprehensive calibration process and verification mechanism ensure the consistency of equipment status, so that the processing results do not change due to changes in operators or time, making it particularly suitable for mass production.

[0023] High system integration: It integrates scattered calibration functions into a unified software platform and control process, making it easy for users to operate and reducing maintenance costs.

[0024] Other features and beneficial effects of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other beneficial effects of this application can be realized and obtained through the structures particularly pointed out in the description and drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships in the drawings described below are based on the direction in which the components are drawn in the figures.

[0026] Figure 1 This is a three-dimensional structural diagram of the laser processing system in Example 1. Figure 1 ; Figure 2 This is a three-dimensional structural diagram of the laser processing system in Example 1. Figure 2 ; Figure 3 This is a schematic diagram of the bottom structure of the laser galvanometer integrated module of the laser processing system in Example 1; Figure 4 A simplified flowchart of the calibration and trajectory control method for a laser processing system; Figure 5 A schematic diagram showing the installation state of the laser interferometer when calibrating the linear axis; Figure 6 This diagram illustrates the installation status of the micrometer and marble reference ruler during the marble compensation process. Figure 1 ; Figure 7 This diagram illustrates the installation status of the micrometer and marble reference ruler during the marble compensation process. Figure 2 ; Figure 8 This diagram illustrates the installation status of the micrometer and marble reference ruler during the marble compensation process. Figure 3 ; Figure 9 A schematic diagram showing the installation status of the calibration ball and probe during the calibration of the C-axis rotation step; Figure 10 A schematic diagram illustrating the positional changes of the calibration ball and probe during the calibration of the C-axis rotation step; Figure 11 A schematic diagram of the structure for calibrating different measurement layers by changing the height of the calibration ball during the calibration of the C-axis rotation step; Figure 12 A schematic diagram showing the installation status of the calibration ball and probe during the calibration of the B-axis rotation step; Figure 13 This is a schematic diagram of the media installation status during the optical path correction step. Figure 14 The images show actual objects with markings engraved on the surface of the medium during the optical path correction step. Figure 15 This is a physical display of the calibration results after applying the calibration parameters to the control module during the optical path calibration step. Figure 16 A schematic diagram showing the installation status of the probe and the plate to be engraved during the hand-eye calibration process; Figure 17 A physical illustration of the correction engraving marks used in the hand-eye calibration process; Figure 18 A physical illustration of the visual-mechanical coordinate system mapping process during hand-eye calibration steps; Figure 19 A diagram showing the installation status of the probe and spray plate when setting the switch cursor steps; Figure 20 A physical display diagram of a set of straight line marks with start and stop delays engraved on a reference surface for hand-eye calibration steps; Figure 21 This diagram shows the installation status of the probe and the calibration plate during the calibration of the C-axis rotation. Figure 22 A physical view of the crosshairs engraved during the calibration of the C-axis rotation. Figure 23 This is a diagram showing the installation status of the probe and the calibration plate after adjusting the height of the calibration plate during the C-axis calibration process. Figure 24 This diagram shows the installation status of the probe and the calibration plate during the calibration of the B-axis rotation. Figure 25 A physical view of the crosshairs engraved during the calibration of the B-axis rotation; Figure 26 A physical illustration of the calibration steps for the B-axis rotation, showing the engraved grid on a standard steel ball. Figure 27 This is a schematic diagram of the structure of a standard steel ball; Figure 28 Microscopic images of the engraved texture on a standard steel ball used in the overall machine accuracy verification process.

[0027] Figure label: 10a, Main body; 100a, Laser galvanometer integrated module; 200a, Work platform; 300a, Probe; 400a, Vision inspection component; 500a, CNC worktable; 510a, Base; 520a, X-axis linear motion mechanism; 530a, Mounting bracket; 540a, Y-axis linear motion mechanism; 550a, Mounting seat; 560a, Z-axis linear motion mechanism; 570a, C-axis rotation mechanism; 580a, B-axis rotation mechanism; 20, Laser interferometer; 30, Dial indicator; 40, Marble reference ruler; 50, Calibration ball; 60, Auxiliary support; 70, Medium; 80, Engraving plate; 90, Spray-coated plate; 100, Calibration plate. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The technical features designed in the different implementations of this application described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] In the description of this application, it should be noted that all terms used in this application (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains, and should not be construed as limiting this application; it should be further understood that the terms used in this application should be understood to have the same meaning as those in the context of this specification and the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this application.

[0030] Example 1: This embodiment uses the calibration and trajectory control method of a laser processing system applied to a five-axis laser processing system for mold texture processing as an example to illustrate the specific implementation of the present invention: See Figure 1A five-axis laser processing system is provided, comprising: a worktable 200a for supporting the workpiece, a laser galvanometer integrated module 100a for outputting a laser beam to act on the workpiece, a CNC worktable 500a, a vision inspection component 400a, a control module, and an integrated control cabinet (containing an industrial computer-type control module and other control-related components). In this embodiment, the main body has five degrees of freedom: movement along the X-axis, movement along the Y-axis, movement along the Z-axis, rotation about a rotation axis parallel to the Z-axis, and rotation about a rotation axis parallel to the X-axis. Its specific implementation structure is as follows: The five-axis laser texturing device includes a main body, which comprises a worktable 200a for carrying a workpiece, a laser galvanometer integrated module 100a for outputting a laser beam to act on the workpiece, a CNC worktable 500a, a probe 300a, a vision inspection component 400a, and a control module; wherein, the worktable 200a and the laser galvanometer integrated module 100a are connected via the CNC worktable 500a, such that the worktable 200a has X-axis and Y-axis orientations relative to the laser galvanometer integrated module 100a. The Z-axis position is adjustable, and the worktable 200a can rotate around a rotation axis parallel to the Z-axis direction. The laser galvanometer integrated module 100a can rotate around a rotation axis parallel to the X-axis direction. The laser galvanometer integrated module 100a includes a housing, and a vision inspection component 400a and a probe 300a are provided at the bottom of the housing. The control module is electrically connected to the CNC worktable 500a, the laser galvanometer integrated module 100a with an embedded control card, the vision inspection component 400a, and the probe 300a.

[0031] For the implementation of five-axis multi-directional motion: the CNC worktable 500a includes a base 510a with an X-axis linear motion mechanism 520a, a mounting frame 530a with a Y-axis linear motion mechanism 540a, a mounting seat 550a with a Z-axis linear motion mechanism 560a, a C-axis rotation mechanism 570a, and a B-axis rotation mechanism 580a; the mounting frame 530a is mounted on the X-axis linear motion mechanism 520a, the worktable 200a is mounted on the Y-axis linear motion mechanism 540a of the mounting frame 530a via the C-axis rotation mechanism 570a, and the mounting seat 550a is fixed to the base 510a; the laser galvanometer integrated module... The 100a is mounted on the Z-axis linear motion mechanism 560a via the B-axis rotation mechanism 580a, so that the positions of the work platform 200a and the laser galvanometer integrated module 100a can be adjusted relative to each other along the X-axis, Y-axis, and Z-axis directions. The work platform 200a can rotate about a rotation axis parallel to the Z-axis direction, and the laser galvanometer integrated module 100a can rotate about a rotation axis parallel to the X-axis direction. The X-axis linear motion mechanism 520a, Y-axis linear motion mechanism 540a, Z-axis linear motion mechanism 560a, C-axis rotation mechanism 570a, and B-axis rotation mechanism 580a are all electrically connected to the control module.

[0032] The calibration tool components also provided include: A laser interferometer 20 is used for acquiring precision data of the linear axis; a reference ruler and dial indicator 30 are used to establish a spatial angular reference and measure perpendicularity deviation; and a calibration ball 50 and a standard steel ball are used for acquiring center coordinate data of the rotation axis. The control module is communicatively connected to the laser interferometer 20, dial indicator 30, and probe 300a. The control module is configured to execute a computer program stored in a memory to implement the calibration method steps described above.

[0033] The laser processing system employs calibration and trajectory control methods to achieve high-precision, highly consistent three-dimensional texture processing on the surfaces of workpieces such as metal molds. The specific implementation process is as follows: 1. Trajectory: S1. Trajectory generation steps: The software imports texture image files and 3D model geometric data of the workpiece into trajectory programming software, sets processing parameters including processing layer information and depth settings, and the core algorithm of the software calculates based on the texture information and processing parameters to automatically generate a digital control trajectory file containing processing path and action instructions. S2. Calibration steps: The laser processing system performs precision calibration and compensation on multiple motion axes and optical paths to establish a high-precision mapping relationship between the mechanical space and the control module. The calibration steps include linear axis calibration, marble platform verticality compensation, rotation axis calibration, and optical path collimation correction. Before the execution step, a workpiece coordinate matching step is also included: at least 3 X / Y plane points and at least 4 Z plane points are collected on the working surface by the pressure sensor of probe 300a to generate a spatial compensation matrix; the collected working reference origin is matched with the digital control trajectory file in real time, and name consistency verification is performed to avoid the risk of manual coordinate offset.

[0034] S3. Execution steps: The digital control trajectory file is transmitted to the laser processing system. The control module parses the trajectory file and drives the CNC worktable 500a to run. Combined with the compensation parameters generated in the calibration steps, laser texture processing operation is performed on the three-dimensional surface of the workpiece.

[0035] 2. Calibration: In this embodiment, the main body has five degrees of freedom, and the calibration process is as follows: 2.1 Calibrate the linear axes (X-axis + Y-axis + Z-axis) and use a laser interferometer 20 to perform accuracy compensation on multiple machine tool axes (such as X-axis, Y-axis, and Z-axis). The core steps include: (1) such as Figure 5 As shown, a laser interferometer 20 is set up and aligned with the target linear axis (such as the X-axis, Y-axis or Z-axis).

[0036] (2) Select the target axis in the linear axis calibration software and configure the calibration range, step interval, motion start point, reciprocating mode and motion parameters (such as overshoot distance and dwell time).

[0037] (3) The position data of the axis is automatically acquired by the software control and the laser interferometer 20 is exported as a TXT file of the specified format.

[0038] (4) After the collected data is imported into the laser processing system, the correction term is selected according to the directionality (forward F / reverse R) and processed in an additional manner.

[0039] (5) Generate the accuracy compensation parameters of the target linear axis and update them to the control module of the laser processing system. The processed compensation data is applied to the internal calibration table of the software and finally takes effect, so that the compensation parameters of the axis are updated.

[0040] (6) After the entire process is completed, the laser interferometer 20 is used again to verify the accuracy.

[0041] 2.2 Marble Compensation (1) such as Figure 6 As shown, after completing linear accuracy compensation, the laser interferometer 20 is removed. A marble reference ruler 40 (including but not limited to a set square or square ruler) is placed, precisely leveled, and fixed on the work stage 200a to establish a spatial angular reference.

[0042] (2) Enable the serial communication function of the linear axis calibration software, set the COM port, and configure motion parameters (such as overshoot distance and dwell time).

[0043] (3) such as Figure 6 , Figure 7 , Figure 8 As shown ( Figure 6 For an example of measuring the Z-axis, Figure 7 For example, measuring the X-axis, Figure 8 For example, when measuring the Y-axis, a dial indicator 30 is used in conjunction with a trigger device (set to event-driven mode) to sequentially measure the two orthogonal directional components of the target axis in a plane perpendicular to its nominal direction (such as the Y-direction and Z-direction of the X-axis).

[0044] (4) The software controls the single-stroke motion of the CNC worktable 500a and triggers the automatic acquisition of data from the dial indicator 30 (i.e., deviations in each vertical direction).

[0045] (5) Select the corresponding calibration item for the measurement position and process the data in an append-only manner (consider the installation direction of the dial indicator 30 and the reverse option).

[0046] (6) Apply this data to update the perpendicularity / angle compensation parameters of the corresponding axis.

[0047] (7) For example Figure 6 , Figure 7 , Figure 8 As shown, under the angular reference established by the reference ruler, the accuracy verification of the corresponding vertical component of the corresponding axis is completed.

[0048] 2.3 Calibrate the rotating shaft In this embodiment, the main body has five degrees of freedom, and its rotation axes include the C-axis and the B-axis. The work platform 200a is mounted on the Y-axis linear movement mechanism 540a of the mounting frame 530a via the C-axis rotation mechanism 570a. The laser galvanometer integrated module 100a is mounted on the Z-axis linear movement mechanism 560a via the B-axis rotation mechanism 580a. The work platform 200a can rotate around the rotation axis C, which is parallel to the Z-axis direction, and the laser galvanometer integrated module 100a can rotate around the rotation axis B, which is parallel to the X-axis direction. The hardware required for calibrating the rotating axis includes a ceramic calibration ball 50, a probe 300a, and corresponding mounting fixtures and possible shims. It should be noted that the probe 300a can be external or internal, and its design can be flexibly adapted to specific needs.

[0049] The specific process for calibrating the rotating axis is as follows: (1) such as Figure 9 As shown, the calibration ball 50 is fixed on the rotating shaft to be calibrated, and the probe 300a is installed and connected to verify the repeatability accuracy of the probe 300a. Figure 9 The diagram shows the installation of the calibration ball 50 when calibrating the C-axis rotation axis. The calibration ball 50 is installed on the worktable 200a.

[0050] (2) such as Figure 10 As shown, the rotation axis is controlled to advance in preset angular steps (e.g., from 0 degrees to a specific angular range), and the probe 300a is used to precisely acquire the coordinate data of the center of the calibration sphere 50. This process is repeated on multiple measurement layers at different heights (set according to the number of calibration layers) to obtain multi-point data in space. Figure 10 As shown, Figure 10 The process of calibrating the C-axis rotation axis is shown. The calibration ball 50 is installed on the work stage 200a, and the probe 300a built into the laser galvanometer integrated module 100a makes multi-directional contact with it.

[0051] (3) such as Figure 11 As shown, by changing the height of the calibration ball 50, calibration is performed on multiple measurement layers at different heights. Using the collected multi-layer and multi-angle position data, the rotation center position and / or axis direction of the rotating shaft are analyzed through a specific algorithm (such as iterative calculation), and its repeatability accuracy is evaluated to see if it meets the preset design requirements.

[0052] (4) Perform the final rotation axis parameter calibration calculation (compensation calculation) to generate and save the final calibration parameter data.

[0053] (5) Verify the preliminary calibration results by repeatedly collecting and analyzing data at key locations to confirm the accuracy after calibration. If the accuracy does not meet the standard, iterate through the data collection and analysis process (may fine-tune the configuration) until the required accuracy is achieved, and finally save the valid calibration data.

[0054] It should be noted that this calibration process for the rotating axis can be used for different rotating axes such as the B-axis and C-axis. The specific axis characteristics can be adapted by adjusting parameters such as the probe type (external / internal), mounting direction, number of measurement layers, and angle range. For different models of laser processing systems, this calibration process can be used to calibrate different rotating axes depending on their actual rotating axis. Similarly, the calibration process for the B-axis is the same as described above. Figure 12 The process of calibrating the B-axis rotation axis is shown. An external probe 300a is fixed on an auxiliary support 60 and then contacts a calibration ball 50 set on a laser galvanometer integrated module 100a.

[0055] 2.4 Optical path correction (1) Set a working height position with a specific offset above and below the effective working distance of the laser processing system.

[0056] (2) such as Figure 13 , Figure 14 As shown, the laser processing system is used to engrave a mark (such as a cross) on the surface of medium 70. The positional deviation between these two marks is precisely measured. This deviation directly reflects the collimation error of the current optical path at different heights. Figure 14 The three small images from left to right respectively show the laser collimation effect after Z-axis calibration, the cross-shaped alignment effect after optical path correction, and the laser collimation effect after XY-axis calibration.

[0057] (3) Using the two set spatial position points and the measured offset, the collimation deviation of the optical path (e.g., the deflection angle of the beam) is dynamically calculated to generate accurate optical correction parameters (compensation values).

[0058] (4) Apply the correction parameters to the control module.

[0059] Figure 15 As shown, after the compensation parameters are loaded, a method backtracking is performed: while still on the reference plane or within its upper and lower range, carving is performed to generate a reference mark.

[0060] The system controls the Z-axis to move to another feature height (such as lifting the reference plane), at which a second mark is engraved.

[0061] Measure the actual deviation between the two new marks again. Ideally, if the correction is accurate, this deviation should be significantly reduced or eliminated. The measured deviation is used to directly evaluate the final correction effect. Figure 15 The two smaller images from left to right respectively show the laser correction effect at multiple heights and the rotation angle correction effect after Z-axis calibration.

[0062] 2.5 Hand-eye calibration, switch cursor calibration, and rotary axis calibration 2.5.1 Hand-eye calibration (1) Figure 16 As shown, the laser focal plane reference point is accurately calibrated using probe 300a, and the reference point of the probe 300a coordinate system is generated by the linked software.

[0063] (2) Figure 17 As shown, a high-precision rotary fixture is used to rotate the plate 80 to be engraved by 180° and engrave double cross marks on the fixed plane of the plate 80. The mark center deviation is eliminated by iterative adjustment (that is, the cross at the 0-degree position and the cross at the 180-degree position are engraved on its surface to correct the position offset until the two crosses coincide), and a precision reference point is established. Figure 17The two small images from left to right show the effect before and after the 180° deviation of the marker center is eliminated.

[0064] (3) such as Figure 18 As shown, the spatial deviation between the laser reference point and the precision calibration point of probe 300a is input into the control module of the laser processing system, and the coordinate transformation parameters (XYZ / XY direction compensation) are calculated and applied to complete the mapping of the vision-machine coordinate system. Figure 18 The two small images from left to right respectively show the effect of the 0° position marking after mapping and the effect of the 180° position marking after mapping.

[0065] 2.5.2 Switch cursor positioning (1) such as Figure 19 As shown, probe 300a calibrates the plane of the sprayed plate 90 (sprayed iron plate) to generate a reference origin.

[0066] (2) For example Figure 20 As shown, a set of straight line marks with start-stop delays are engraved on the reference plane, and the deviation between the endpoints and the reference line is quantified by microscope. Figure 20 The two small images from left to right respectively show several groups of straight line marks on the reference plane and the alignment effect of a group of straight line marks under a microscope with the reference line.

[0067] (3) Quantify and compensate the switching optical delay of the laser galvanometer integrated module 100a according to the deviation.

[0068] 2.5.3 Rotary Axis Calibration C-axis calibration (1) such as Figure 21 As shown, the calibration plate 100 is placed above the worktable 300, and a cross mark of ±45° is engraved on the calibration plate 100 (the iron plate to be calibrated) (see the actual image of the mark). Figure 22 As shown, Figure 22 The four small images from left to right respectively show the effect of the cross mark on the calibration plate before calibration, the effect of the vertical line of the ±45° cross mark coinciding, the effect of the horizontal line of the ±45° cross mark coinciding, and the effect of the cross mark on the calibration plate after calibration. The position of the rotation center is calibrated by the center deviation of the double cross mark.

[0069] (2) For example Figure 23 As shown, move the calibration plate 100 meters to a height, and engrave verification marks on planes at different heights to check the center coincidence and confirm the normal accuracy.

[0070] B-axis calibration (1) Similarly, such as Figure 24 As shown, a cross mark of ±45° is engraved on the calibration plate 100 (the iron plate to be calibrated). (The cross mark is as shown in the image.) Figure 25 As shown in the figure, the normal error is identified through the deviation pattern.

[0071] (2) For example Figure 26 The schematic diagram shows the standard steel ball after engraving. A grid is engraved on the surface of the standard ball (standard steel ball), and the normal calibration effect is verified by splicing continuity.

[0072] Note: The above-mentioned step 2.3, calibrating the rotary axis, involves using probe 300a to touch the calibration ball 50 to perform position compensation on the motion axis, which is an adjustment of the axis. The 2.5.3 rotary axis calibration step involves calibrating and adjusting the laser galvanometer by using a laser to create a cross pattern; these are two different steps.

[0073] 2.6 Overall Machine Accuracy Verification like Figure 27 , 28 As shown, a reference coordinate system is established on the surface of a standard sphere (standard steel sphere). The laser galvanometer integrated module 100a is controlled to perform texture engraving on the surface of the standard steel sphere, and the engraved texture is as follows. Figure 28 The microscopic magnification of the surface texture of the standard steel ball is shown. The deviation between the endpoint and the reference line is quantified by microscope to verify the overall accuracy of the entire laser processing system.

[0074] Based on the above, the calibration and trajectory control method of the laser processing system in this application embodiment has the following beneficial effects: Comprehensive precision improvement: Through an integrated multi-sensor calibration system, all factors affecting processing accuracy (linear positioning, perpendicularity, rotation center, optical path, coordinate system mapping) are fully compensated, improving the overall processing accuracy to the micron level and meeting the needs of high-end three-dimensional texture processing; High degree of automation and intelligence: From data acquisition and calculation to the application of compensation parameters, the entire process is highly automated, which greatly reduces the reliance on manual experience and human intervention, improves efficiency, and reduces the error rate.

[0075] True 3D machining capability: It solves the industry challenge of high-precision machining on complex 3D curved surfaces, especially by ensuring a high degree of consistency between the laser path and the 3D model through calibration steps such as rotation axis calibration and hand-eye calibration.

[0076] Excellent repeatability and consistency: The comprehensive calibration process and verification mechanism ensure the consistency of equipment status, so that the processing results do not change due to changes in operators or time, making it particularly suitable for mass production.

[0077] High system integration: It integrates scattered calibration functions into a unified software platform and control process, making it easy for users to operate and reducing maintenance costs.

[0078] It should be noted that: In the laser processing system, the Y-axis linear motion mechanism 540a, X-axis linear motion mechanism 520a, and Z-axis linear motion mechanism 560a can adopt existing reciprocating linear motion mechanisms. The driving components include, but are not limited to, existing motors and other driving components (e.g., a servo motor is used for the Z-axis driving component) to drive the push component to slide on the slide rail.

[0079] The core components of the laser galvanometer integrated module 100a system include optical components and a control card. The optical components include a laser generator, a reflector, a beam expander, a beam combiner, a coaxial camera, a galvanometer, and a field lens. It integrates the galvanometer scanning module, the field lens module (field lens + adapter ring), the laser emission module (laser generator + beam expander / reflector), and the machine vision system (camera + coaxial lens with filter + light source) into a single compact module to achieve laser processing and real-time visual control.

[0080] The calibration and trajectory control method for the laser processing system provided in this application is based on its application in a five-axis laser processing system, but it is not limited to the application in a five-axis laser processing system. For example, it can also be applied to three-axis, four-axis, etc. The specific linear axis calibration, rotary axis calibration and other steps are based on the linear motion axis and rotary axis of the actual equipment.

[0081] In this paper, the five-axis CNC worktable typically includes three linear motion axes (X, Y, and Z axes) and two rotary axes (such as the B axis around the X axis and the C axis around the Z axis).

[0082] The trajectory programming software and its core algorithm are existing technologies and will not be elaborated here.

[0083] Those skilled in the art should understand that, despite the many problems existing in the prior art, each embodiment or technical solution of this application can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0084] Although this document frequently uses terms such as calibration, trajectory, and verticality compensation, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this application; interpreting them as any additional limitation would contradict the spirit of this application. The terms "first," "second," etc. (if present) in the description, claims, and accompanying drawings of the embodiments of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A calibration and trajectory control method for a laser processing system, characterized in that: Provide a laser processing system; The laser processing system comprises a worktable for supporting the workpiece, a laser galvanometer integrated module for outputting a laser beam onto the workpiece, a CNC worktable, a vision inspection component, and a control module. The worktable, laser galvanometer integrated module, and vision inspection component are mounted on the CNC worktable, allowing adjustment of the relative positions of the worktable and the laser galvanometer integrated module, and the relative positions of the worktable and the vision inspection component. The control module is electrically connected to the CNC worktable, the laser galvanometer integrated module, and the vision inspection component. The worktable and laser galvanometer integrated module are mounted on the CNC worktable, allowing adjustment of the relative positions of the worktable and the laser galvanometer integrated module, and the laser galvanometer integrated module. The platform relative to the laser galvanometer integrated module has positional adjustment along the X-axis, Y-axis, and Z-axis directions; the provided laser processing system also includes a movable contact measurement probe with movable position, and the probe is electrically connected to the control module; the CNC worktable is a five-axis CNC worktable, and the worktable and the laser galvanometer integrated module are disposed on the CNC worktable so that the worktable relative to the laser galvanometer integrated module has positional adjustment along the X-axis, Y-axis, and Z-axis directions, and the worktable can rotate about a rotation axis C parallel to the Z-axis direction, and the laser galvanometer integrated module can rotate about a rotation axis B parallel to the X-axis direction; The calibration and trajectory control method includes the following steps: S1. Trajectory generation step: Import texture image files and 3D model geometric data of the workpiece into trajectory programming software, set processing parameters including processing layer information and depth settings, and the core algorithm of the software calculates based on texture information and processing parameters to automatically generate a digital control trajectory file containing processing path and action instructions. S2. Calibration steps: Perform precision calibration and compensation on multiple motion axes and optical paths of the laser processing system to establish a high-precision mapping relationship between the mechanical space and the control module. The calibration steps include linear axis calibration, marble platform verticality compensation, first calibration of the rotation axis, and optical path collimation correction. The target linear axis in the linear axis calibration process includes one or more of the X-axis, Y-axis, and Z-axis directions. A calibration tool assembly is also provided, including a laser interferometer. The linear axis calibration process is as follows: the laser interferometer is aligned with the target linear axis; the calibration range, step interval, motion start point, and reciprocating motion parameters are configured in the linear axis calibration software; the laser interferometer is controlled by the linear axis calibration software to automatically collect the position data of the target linear axis and export the data file; the collected data is processed in an append-only manner, selecting positive or negative correction terms based on the motion direction, to generate accuracy compensation parameters for the target linear axis and update them to the control module of the laser processing system; the laser interferometer is used to verify the accuracy of the compensated axis. The system also provides a calibration tool component, which includes a reference ruler and a dial indicator. The verticality compensation process of the marble platform is as follows: the reference ruler is placed, leveled, and fixed on the worktable after linear accuracy compensation to establish a spatial angle reference; the serial communication function of the linear axis calibration software is enabled, and motion parameters are configured; the dial indicator is used in conjunction with a trigger device, set to event-driven mode, to measure the two orthogonal directional components of the target linear axis in a plane perpendicular to its nominal direction; the single-stroke motion of the CNC worktable is controlled to automatically collect the vertical deviation data of the dial indicator at each measurement position; according to the installation direction and inversion option of the dial indicator, the corresponding correction item is selected at the measurement position, and the collected deviation data is processed in an append manner to generate parameters for updating the verticality and angle compensation of the corresponding axis; under the angle reference established by the reference ruler, the accuracy verification of the corresponding vertical component of the corresponding axis is completed. The system also provides a calibration tool assembly, which includes a calibration ball and a mounting fixture. The first calibration process for the rotating axis is as follows: the calibration ball is fixed on the rotating axis to be calibrated, and the repeatability of the probe assembly is verified; the rotating axis is controlled to rotate in steps at a preset angle, and the worktable is controlled to rotate along the C-axis or the laser galvanometer integrated module is controlled to rotate along the B-axis via a CNC worktable; the probe is moved relative to the calibration ball and contacts the calibration ball at multiple measurement layers of different heights to accurately collect the coordinate data of the center of the calibration ball; using the collected multi-layer and multi-angle position data, the rotation center position and / or axial direction of the rotating axis are analyzed through an iterative calculation algorithm, and its repeatability is evaluated; the rotating axis parameter calibration calculation is performed to generate the final calibration compensation parameters and save them; the calibration results are verified by measurement, and if the accuracy does not meet the standard, data acquisition and analysis are iteratively performed until the preset accuracy requirement is met; The optical path collimation correction process is as follows: two different working height positions are set above and below the effective working distance of the laser processing system; the laser processing system is controlled to engrave a mark on the surface of the medium at each of the two different working height positions; the positional deviation between the two marks is measured to calculate the collimation deviation of the current optical path at different heights and the beam deflection angle; optical correction parameters are dynamically calculated based on the deviation and applied to the control module; after the compensation parameters are loaded, backtracking verification is performed: a reference mark is engraved at the reference height, a second mark is engraved at another feature height, and the actual deviation between the two new marks is measured again to verify the correction effect; S3. Workpiece coordinate matching and execution steps: First, the workpiece coordinate matching step is performed. At least 3 X / Y plane points and at least 4 Z plane points are collected on the working surface through probe pressure sensing to generate a spatial compensation matrix. The collected working reference origin is matched with the digital control trajectory file in real time, and name consistency verification is performed to avoid the risk of manual coordinate offset. Then, the execution step is performed. The digital control trajectory file is transmitted to the laser processing system. The control module parses the trajectory file and drives the CNC worktable to run. Combined with the compensation parameters generated in the calibration step, laser texture processing operation is performed on the three-dimensional surface of the workpiece. The calibration steps also include hand-eye calibration, switch cursor calibration, and a second calibration of the rotating axis; The hand-eye calibration process is as follows: the laser focal plane reference point is precisely calibrated using a probe, and the probe coordinate system reference point is generated by the linked software; the plate to be engraved is rotated 180° using a high-precision rotary fixture, and double cross marks are engraved on the fixed plane of the plate to be engraved. The deviation of the mark center is eliminated by iterative adjustment, and a visual precision reference point is established; the spatial deviation between the laser reference point and the precision point of the probe is input into the control module of the laser processing system, the spatial deviation between the laser reference point and the visual precision reference point is calculated, and the XYZ three-direction and XY two-direction compensation parameters are applied to complete the mapping between the visual coordinate system and the mechanical coordinate system; The switch calibration process is as follows: the probe calibrates the plane of the spray plate to generate a reference origin; a set of straight line marks containing start and stop delays is engraved on the reference surface, and the deviation between the endpoint and the reference line is quantified by a microscope; The second calibration step of the rotating axis includes the C-axis calibration process and the B-axis calibration process; The C-axis calibration process is as follows: the calibration plate is placed on the worktable, and a cross mark of ±45° is engraved on the calibration plate. The rotation center position is calibrated by the center deviation of the double cross mark. The height of the calibration plate is moved, and verification marks are engraved on planes at different heights to check the center coincidence and confirm the normal accuracy. The B-axis calibration process includes: engraving a cross mark of ±45° on the calibration plate and identifying the normal error through deviation pattern identification; engraving a grid on the surface of a standard sphere and verifying the normal calibration effect through splicing continuity.

2. The method according to claim 1, characterized in that, After the calibration step, the overall machine accuracy verification step is performed. The overall accuracy verification process is as follows: a reference coordinate system is established on the surface of a standard sphere; the laser galvanometer integrated module is controlled to perform texture engraving on the surface of the standard sphere, and the deviation between the endpoint and the reference line is quantified by a microscope.

3. A laser processing system for implementing the method according to any one of claims 1 to 2, characterized in that, include: Worktable: Used to support workpieces; Laser galvanometer integrated module: used to output laser beam; CNC worktable: used to adjust the relative position of the worktable and the laser galvanometer integrated module; Probes are used for contact measurements; Visual inspection components for visual inspection; The control module is communicatively connected to the laser galvanometer integrated module, the CNC worktable, the vision inspection component, and the probe component; The control module is configured as follows: The functions of the trajectory programming software are executed to generate the digital control trajectory file; Perform the aforementioned procedures for linear axis calibration, marble platform verticality compensation, first calibration of the rotation axis, and optical path collimation correction; The CNC worktable is controlled to parse and execute the trajectory file.

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