Data processing method and processing method suitable for laser texture engraving of complex curved surface

Abstract

The present application provides a data processing method and processing method suitable for laser texture engraving of complex curved surface, including analyzing processing requirements, meshing the complex curved surface to be processed, performing UV operation on the generated mesh, assigning the mesh with UV expanded to gray-scale texture map used for engraving, slicing the mesh and establishing a local coordinate system, generating projection graphics under the local coordinate system of the slice, generating five-axis motion mechanism positioning point data and laser galvanometer scanning path data, and generating corresponding five-axis motion mechanism positioning point data and laser galvanometer scanning path data for each slice of each engraving layer. Through the steps of meshing, UV expanding, slicing, and projecting the engraving texture graphics to the local coordinate system of the slice, the laser texture engraving of the complex curved surface can be realized by using the two-axis laser galvanometer cooperating with the five-axis motion mechanism.

Description

Technical Field

[0001] This invention belongs to the field of laser processing technology, and specifically relates to a data processing method and processing method suitable for laser texture engraving of complex curved surfaces. Background Technology

[0002] In industries such as aerospace, automotive, energy, petrochemical, power, and military defense, components with complex curved surfaces have a wide range of applications, such as aircraft wings, marine propellers, engine blades, automotive body panel molds, and large diesel engine crankshafts, all of which have complex spatial curved surfaces.

[0003] Currently, there are three main laser processing methods suitable for complex curved surface parts:

[0004] (1) Focused laser beam machining technology based on five-axis or three-axis CNC machine tools. The machining principle of this method is the same as that of conventional tool-based CNC machine tool machining, except that the laser beam is regarded as a tool. The movement of the laser focus depends on the mechanical movement of the machine tool spindle, so the machining efficiency is low;

[0005] (2) "3+2 axis" laser galvanometer projection processing technology. A laser galvanometer typically consists of two laser plane mirrors and a scanning focusing lens. Its working principle involves expanding the laser beam extracted from the laser resonant cavity, reflecting it through a pair of vertically mounted, servo-motor-driven folding mirrors (referred to as the X and Y axis laser plane mirrors), and then focusing it using the scanning focusing lens (F-theta lens or telecentric lens) before outputting it onto the object to be processed. The rotation of the X and Y axis laser plane mirrors causes the focused spot on the working plane to move along the X and Y axes, respectively. The coordinated movement of the two mirrors allows the focused laser spot to move in straight lines and various curves on the working plane. The incident angle of the beam and the position of the spot on the image plane satisfy a linear relationship, thus controlling the position of the spot on the image plane by controlling the scanning angle of the incident beam. Because the galvanometer is lightweight, its rotational inertia is small when driven by the motor, resulting in significant acceleration. Therefore, it is possible to control the laser beam to complete high-speed scanning motion. This laser galvanometer scanning machining method based on beam deflection far surpasses the scanning machining method using mechanical axes in both processing speed and accuracy, and has therefore been widely used in manufacturing. However, it is basically limited to two-dimensional planar machining and cannot meet the machining requirements of three-dimensional complex curved surfaces. For the machining of three-dimensional complex curved surface parts, the Chinese patent application number 201010115968.0, entitled "A Projection-Type Laser Etching Method on Free-Form Surfaces," is based on a machining system of a three-axis CNC machine tool and a two-axis deflecting galvanometer. It divides the complex curved surface parts described by a discrete point cloud model into sub-blocks, projects the machining graphic in parallel, and splits it into sub-blocks. The three-axis CNC machine tool is used to locate the machining position of each sub-block, and each sub-block is completed by laser galvanometer scanning. This method takes advantage of the characteristic that the laser processing characteristics such as the shape, size, and energy distribution of the laser spot remain unchanged within the focal depth range of the focusing lens. During the block machining, the high-speed rotation of the two plane mirrors in the galvanometer mainly relies on the high-speed scanning of the laser beam to achieve precision etching. Compared with the processing method in scheme (1) that relies on the movement of mechanical shafts to achieve laser beam scanning, the "3+2 axis" laser galvanometer projection processing technology can significantly improve the efficiency and accuracy of laser etching.

[0006] However, this "3+2 axis" laser galvanometer projection processing technology has the following main problems:

[0007] Because the maximum difference in the Z-axis of the point cloud data within a sub-block must be less than the laser focal depth determined by the focusing optical path of the laser processing machine tool when dividing the surface into sub-blocks, otherwise the quality of laser etching cannot be guaranteed, the sub-blocks must be extremely small for complex curved surfaces with large curvature. This leads to a sharp increase in the number of sub-blocks, resulting in very frequent sub-block positioning movements on the three-axis machine tool and extremely low processing efficiency. Furthermore, since this "3+2 axis" laser galvanometer projection processing technology has only one fixed light projection direction, the laser beam cannot reach surfaces that are opposite to the laser incident direction or steep surfaces parallel to the laser beam direction, thus preventing processing. Therefore, this method is only suitable for precision machining of surface graphics with large radii of curvature and simple shapes.

[0008] (3) Machining technology based on a five-axis CNC machine tool plus a two-axis laser galvanometer. For example, Chinese patent application number 201110048935.3, invention title "A laser processing method and device applicable to complex curved surfaces", is based on a machining system of a five-axis CNC machine tool + a three-axis (or two-axis) deflection galvanometer. By dividing the complex curved surface into curved surface patches and establishing a local coordinate system for each curved surface patch, the curved surface patch is divided into sub-blocks, and the machining graphics on the sub-blocks are projected parallel to the local coordinate system of the curved surface patch. The machining position of each sub-block is located using a five-axis CNC machine tool, and each sub-block is completed by scanning with a laser galvanometer. This method solves the limitation of the above (2) method, which can only use a single coordinate system for overall projection, resulting in the inability to process machining surfaces that are back to the laser incident direction or steep surfaces that are close to the laser incident direction, thus expanding the scope of application of the machining.

[0009] However, this method based on surface patch segmentation has the following main problems:

[0010] In laser engraving of textures on mold parts, grayscale images are typically used to design the engraving textures, as they can represent complex and intricate patterns. However, due to the use of curved surface patches, it is difficult to apply grayscale images onto curved surfaces, and it is also difficult to control the deformation that occurs after the grayscale image is applied to the curved surface. For intricate graphics, the surface projection calculation is quite complex and time-consuming. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this invention provides a data processing method and processing method suitable for laser texture engraving on complex curved surfaces. It solves the limitations of existing methods based on curved surface segmentation projection, such as difficulty in using grayscale images, difficulty in controlling the deformation of grayscale images after they are applied to curved surfaces, as well as the complexity and long computation time of calculations, thereby improving the efficiency of data calculation.

[0012] A data processing method suitable for laser texture engraving on complex curved surfaces includes the following steps:

[0013] Step 1: Analyze processing requirements, select appropriate processing parameters, and determine key parameters such as the effective scanning range of the laser scanning galvanometer, the laser processing focal length, the laser beam focal spot diameter and focal depth, and the number of laser engraving layers.

[0014] Step 2: Mesh the complex surface to be processed. During meshing, the chord error and the side length of the triangle must be less than the set threshold. After meshing, a mesh approximates the complex surface is obtained.

[0015] Step 3: Perform UV unwrapping on the generated mesh to reduce the deformation caused by the texture map being applied to the mesh;

[0016] Step 4: Apply the grayscale texture map used for sculpting to the UV-unwrapped mesh;

[0017] Step 5: Slice the mesh and establish a local coordinate system for each slice;

[0018] Step 6: For each slice, generate the local coordinate system XY plane of the slice. This XY plane is the working plane of the laser galvanometer. Project the graphic corresponding to the gray level of the layer to be etched in the grayscale image on the triangle inside the slice onto the working plane of the slice along the Z-axis of the local coordinate system of the slice to obtain the projected graphic.

[0019] Step 7: For each slice, generate five-axis motion mechanism positioning point data based on the center point and normal direction of the working plane corresponding to the slice, and generate laser galvanometer scanning path data based on the projection graphic obtained by projecting the graphic to be processed on the slice along the Z-axis of the local coordinate system of the slice onto the working plane of the slice.

[0020] Step 8: Based on the number of engraving layers, take several gray levels in the grayscale image as one engraving layer. For each engraving layer in the grayscale image, repeat steps 5-7 to generate the five-axis motion mechanism positioning point data and laser galvanometer scanning path data corresponding to each slice of each engraving layer.

[0021] By adopting the above technical solution, and by performing UV unwrapping and mesh slicing operations on the mesh, the problems of difficulty in applying grayscale images to curved surfaces and difficulty in controlling the deformation of grayscale images after they are applied to curved surfaces are solved. At the same time, because a mesh is used, various algorithms widely used in computer graphics can be used when calculating texture graphics projection, thereby accelerating the calculation process and improving the efficiency of data calculation.

[0022] By transforming steep, high-curvature surfaces in a single coordinate system into flat, low-curvature surfaces in the slice's local coordinate system, it becomes possible to machine component surfaces that were previously impossible to process using a single ray projection method, either facing away from or nearly parallel to the laser incident direction. Furthermore, threshold parameters are used to control the number of generated mesh triangles, slice size, and the number of slices, allowing for optimization between processing quality and efficiency.

[0023] Optionally, in step 2, a smaller chord error setting results in a mesh that closely resembles the original surface, leading to less deformation caused by image projection and higher engraving quality. However, this also results in a denser mesh, longer data computation time, and lower processing efficiency. Similarly, the triangle side length threshold should ensure that a single triangle does not exceed the effective scanning range of the laser galvanometer. Likewise, a smaller triangle side length threshold setting results in smaller meshed triangles, a mesh that closely resembles the original surface, less deformation caused by image projection, and higher engraving quality. However, this also leads to a denser mesh, longer data computation time, and lower processing efficiency.

[0024] Optionally, in step 5, the maximum difference in the Z coordinates of all triangles within the slice under the slice's local coordinate system must be less than the focal depth of the laser beam output by the laser galvanometer and scanning focusing lens module to be used. The angle between the positive direction of the normal of the triangles within the slice and the positive direction of the Z-axis of the slice's local coordinate system must be less than a set threshold. Furthermore, all triangles on the slice are projected parallel to the Z-axis direction of the slice's local coordinate system onto the XY plane of the slice's local coordinate system, and the area occupied by the resulting projected triangles must be within the effective scanning range of the laser galvanometer to be used.

[0025] Optionally, in step 5, the local coordinate system of the slice is defined by taking the direction of the normal to the base of the smallest cuboid bounding box of the triangle within the slice, which is opposite to the outer surface of the slice, as the positive direction of the Z-axis, and the projection vector of the Z-axis of the world coordinate system onto the base as the positive direction of the Y-axis. The X-axis direction is determined according to the right-hand rule. The axis-aligned bounding box of the triangle within the slice in the XYZ axis directions of the slice's local coordinate system established above is the axis-aligned smallest bounding box of the slice, and the center point of this bounding box is the origin of the slice's local coordinate system.

[0026] Optionally, when the Z-axis of the world coordinate system is perpendicular to the bottom surface of the smallest cuboid bounding box of the triangle inside the slice that is opposite to the outer surface of the slice, the positive direction of the Y-axis of the world coordinate system is taken as the positive direction of the Y-axis of the local coordinate system of the slice.

[0027] Optionally, in step 8, the number of gray levels in a single engraving layer is obtained by dividing the total number of gray levels in the grayscale image by the number of engraving layers.

[0028] A processing method suitable for laser texture engraving of complex curved surfaces is proposed. The method uses a data processing method suitable for laser texture engraving of complex curved surfaces to obtain data for processing. A five-axis motion mechanism is used in conjunction with a two-axis laser galvanometer and a scanning focusing lens module to perform laser scanning processing on the surface of the workpiece to be processed.

[0029] Optionally, for each slice of each layer to be engraved, a five-axis motion mechanism is used. Based on the positioning point data of the five-axis motion mechanism generated in step 7, the laser galvanometer and scanning focusing lens module are positioned to align with the origin of the local coordinate system of the slice. The normal direction at the center of the scanning focusing lens coincides with the Z-axis direction of the local coordinate system of the slice, and the distance from the scanning focusing lens to the working plane of the slice is equal to the laser processing focal length, so that the laser beam can be focused on the working plane of the slice. Then, the scanning action of the laser galvanometer is used to perform scanning processing according to the laser galvanometer scanning path data generated in step 7.

[0030] Optionally, laser texture engraving can be completed on the entire surface of the workpiece by traversing and processing each slice of each layer.

[0031] By adopting the above technical solution, the five-axis linkage machine tool only needs to position the laser galvanometer and scanning focusing lens mechanism to the center point of the local coordinate system of the aligned slice. The texture graphics are mainly completed by the high-speed scanning action of the laser scanning galvanometer. Because the laser scanning galvanometer has a small mass, small moment of inertia, and large acceleration, the processing efficiency is greatly improved.

[0032] A storage medium stores a data processing program designed using a data processing method suitable for laser texture engraving on complex curved surfaces. The data processing program is used to generate laser galvanometer scanning path data and positioning point data of a five-axis motion mechanism.

[0033] A data processing device includes a memory and a processor. The memory stores a data processing method suitable for laser texture engraving on complex curved surfaces. The processor runs a data processing program and outputs generated laser galvanometer scanning path data and five-axis motion mechanism positioning point data.

[0034] In summary, the present invention has at least the following beneficial technical effects:

[0035] (1) Compared with the focused laser etching technology based on a five-axis linkage CNC machine tool, the former relies entirely on the mechanical axes of the machine tool to complete the movement of the laser beam during the laser etching process. When engraving fine textures on the surface of complex curved parts, the mechanical axes of the machine tool frequently accelerate and decelerate, resulting in low processing efficiency and high energy consumption. However, with the technical solution of this invention, the five-axis linkage machine tool only needs to position the laser galvanometer and scanning focusing lens mechanism to the center point of the local coordinate system of the aligned slice. The texture pattern is mainly completed by the high-speed scanning action of the laser scanning galvanometer. Since the laser scanning galvanometer has a small mass, small moment of inertia, and large acceleration, the processing efficiency is greatly improved.

[0036] (2) Compared with the "3+2 axis" laser galvanometer projection processing technology, this invention effectively solves the limitation of the existing "3+2 axis" laser galvanometer projection processing technology, which has only one light projection direction and can only use a single coordinate system for overall projection, by slicing the mesh and establishing a local coordinate system for the slices, and projecting the texture on the slices into the local coordinate system of the slices. This invention transforms the large curvature and steep surface under the single coordinate system into a small curvature and flat surface under the local coordinate system of the slices, making it possible to process the surface of parts that was originally impossible to process under the single light projection method, such as those facing away from the laser incident direction or those that are nearly parallel to the laser incident direction. At the same time, threshold parameters are used to control the number of generated mesh triangles, slice size, and number of slices, thereby optimizing the processing quality and processing efficiency.

[0037] (3) Compared with the “5+2 axis” laser galvanometer projection processing technology based on surface segmentation, the present invention solves the problem of difficulty in applying grayscale images on curved surfaces and difficulty in controlling the deformation of grayscale images after they are applied to curved surfaces by performing UV unwrapping and mesh slicing operations on the mesh; at the same time, due to the use of mesh, various algorithms widely used in computer graphics can be used when calculating texture graphics projection, thereby accelerating the calculation process and improving the efficiency of data calculation.

[0038] (4) The laser processing device designed in this invention has a laser processing head module composed of a 2-axis laser galvanometer and a scanning focusing lens. The processing head is independent and has a compact structure. It can be combined with commercial CNC machine tools to form a laser etching processing machine tool, and therefore has important practical value. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating a data processing method for laser texture engraving of complex curved surfaces according to the present invention.

[0040] Figure 2 This is a schematic diagram illustrating the meshing of complex curved surfaces in this invention;

[0041] Figure 3This is a schematic diagram of UV unwrapping operation on the mesh in this invention;

[0042] Figure 4 This is a schematic diagram of how the grayscale image used for engraving is applied to a grid with unfolded UV coating in this invention;

[0043] Figure 5 This is a schematic diagram of one of the slices after the mesh is sliced ​​in this invention;

[0044] Figure 6 This is a schematic diagram of the parallel projection of the slices onto the working plane after slicing the mesh in this invention;

[0045] Figure 7 This is a schematic diagram of generating a laser scanning path based on the image projected onto the working plane from a slice in this invention;

[0046] Figure 8 This is a schematic diagram of a typical five-axis CNC machine tool structure combined with a two-axis laser galvanometer and scanning focusing lens module, applicable to the processing method of laser texture engraving on complex curved surfaces according to the present invention. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings.

[0048] This invention discloses a data processing method and a processing method applicable to laser texture engraving of complex curved surfaces, suitable for various laser wavelengths, power, scanning speeds and other process parameters.

[0049] Reference Figures 1-8 Example 1: A data processing method suitable for laser texture engraving on complex curved surfaces, comprising the following steps:

[0050] Step 1: Analyze processing requirements, select appropriate processing parameters, and determine key parameters such as the effective scanning range of the laser scanning galvanometer, the laser processing focal length, the laser beam focal spot diameter and focal depth, and the number of laser engraving layers.

[0051] Step 2: Mesh the complex surface to be processed. During meshing, the chord error and the side length of the triangles must be less than a set threshold. After meshing, a mesh approximating the complex surface is obtained, such as... Figure 2 As shown;

[0052] Step 3: Perform UV unwrapping on the generated mesh to reduce deformation after the texture map is applied to the mesh, such as... Figure 3 As shown;

[0053] Step 4: Apply the grayscale texture map used for sculpting to the UV-unwrapped mesh, such as... Figure 4 As shown;

[0054] Step 5: Slice the mesh and establish a local coordinate system for each slice, such as... Figure 5 As shown;

[0055] Step 6: For each slice, generate the local coordinate system XY plane of the slice. This XY plane is the working plane of the laser galvanometer. Project the image corresponding to the gray level of the layer to be etched in the grayscale image on the triangle within the slice onto the working plane of the slice along the Z-axis of the local coordinate system to obtain the projected image, such as... Figure 6 As shown;

[0056] Step 7: For each slice, generate positioning point data for the five-axis motion mechanism based on the center point and normal direction of the corresponding working plane. Generate laser galvanometer scanning path data based on the projection of the graphic to be processed on the slice onto the working plane along the Z-axis of the slice's local coordinate system. Figure 7 As shown;

[0057] Step 8: Based on the number of engraving layers, take several gray levels in the grayscale image as one engraving layer. For each engraving layer in the grayscale image, repeat steps 5-7 to generate the five-axis motion mechanism positioning point data and laser galvanometer scanning path data corresponding to each slice of each engraving layer.

[0058] When implementing the method described in this invention, the processing requirements should first be analyzed. Based on the constituent materials and processing range dimensions of the parts to be processed, and the processing requirements, appropriate laser scanning galvanometers, scanning focusing lenses, and suitable processing parameters should be selected. Specifically, by selecting appropriate laser sources, light guiding systems (beam expanders, collimating lenses, optical fibers, hard optical paths composed of lenses, laser galvanometers, etc.), two-axis scanning laser galvanometers capable of meeting processing requirements, and scanning focusing lenses with suitable aperture and focal length, key parameters such as the effective scanning range of the laser scanning galvanometer, the laser processing focal length, the laser beam focal spot diameter, and the depth of focus are determined accordingly. By determining the processing parameters, such as laser emission power, frequency, pulse width, and laser scanning galvanometer scanning speed, the etching depth of the laser beam scanning the surface of the parts in one pass is determined. Based on the maximum required etching depth, the number of layers to be etched (maximum etching depth / etching depth per scan) can be calculated.

[0059] In Example 2, in step 5, the maximum difference in the Z-coordinates of all triangles within the slice under the slice's local coordinate system must be less than the focal depth of the laser beam output by the laser galvanometer and scanning focusing lens module to be used. The angle between the positive direction of the triangle normal and the positive direction of the Z-axis of the slice's local coordinate system must be less than a set threshold. Furthermore, all triangles on the slice are projected parallel to the Z-axis of the slice's local coordinate system onto the XY plane of the slice's local coordinate system, and the area occupied by the resulting projected triangles must be within the effective scanning range of the laser galvanometer to be used.

[0060] In Example 3, in step 5, the local coordinate system of the slice is defined by the positive Z-axis direction of the normal to the base of the smallest cuboid bounding box of the triangle within the slice, which is opposite to the outer surface of the slice. The positive Y-axis direction is defined by the projection vector of the Z-axis of the world coordinate system onto the base. The X-axis direction is determined according to the right-hand rule. The axis-aligned bounding box of the triangle within the slice in the XYZ axis directions of the slice's local coordinate system established above is the axis-aligned minimum bounding box of the slice, and the center point of this bounding box is the origin of the slice's local coordinate system.

[0061] Example 4: When the Z-axis of the world coordinate system is perpendicular to the bottom surface of the smallest cuboid bounding box of the triangle inside the slice, which is opposite to the outer surface of the slice, the positive direction of the Y-axis of the world coordinate system is taken as the positive direction of the Y-axis of the local coordinate system of the slice.

[0062] In Example 5, the number of gray levels in a single engraving layer in step 8 is obtained by dividing the total number of gray levels in the grayscale image by the number of engraving layers.

[0063] Example 6: A processing method suitable for laser texture engraving of complex curved surfaces. The method uses a data processing method suitable for laser texture engraving of complex curved surfaces to obtain data for processing. A five-axis motion mechanism is used in conjunction with a two-axis laser galvanometer and a scanning focusing lens module to perform laser scanning processing on the surface of the workpiece to be processed.

[0064] In Example 7, for each slice of each layer to be engraved, a five-axis motion mechanism is used. Based on the positioning point data of the five-axis motion mechanism generated in step 7, the laser galvanometer and scanning focusing lens module are positioned to align with the origin of the local coordinate system of the slice. The normal direction at the center of the scanning focusing lens coincides with the Z-axis direction of the local coordinate system of the slice, and the distance from the scanning focusing lens to the working plane of the slice is equal to the focal length of the laser processing. This allows the laser beam to be focused onto the working plane of the slice. Then, the scanning action of the laser galvanometer is used to perform scanning processing according to the scanning path data of the laser galvanometer generated in step 7.

[0065] Example 8: Laser texture engraving is completed on the entire surface of the workpiece by traversing and processing each slice of each layer.

[0066] Example 9: A storage medium storing a data processing program designed using a data processing method suitable for laser texture engraving on complex curved surfaces. The data processing program is used to generate laser galvanometer scanning path data and five-axis motion mechanism positioning point data.

[0067] Example 10: A data processing device includes a memory and a processor. The memory stores a data processing method suitable for laser texture engraving on complex curved surfaces. The processor runs a data processing program and outputs generated laser galvanometer scanning path data and five-axis motion mechanism positioning point data.

[0068] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A data processing method suitable for laser texture engraving on complex curved surfaces, characterized in that: Includes the following steps: Step 1: Analyze processing requirements, select appropriate processing parameters, and determine the effective scanning range of the laser scanning galvanometer, the laser processing focal length, the laser beam focal spot diameter and focal depth, and the number of laser engraving layers. Step 2: Mesh the complex surface to be processed. During meshing, the chord error and the side length of the triangle must be less than the set threshold. After meshing, a mesh approximates the complex surface is obtained. Step 3: Perform UV unwrapping on the generated mesh to reduce the deformation caused by the texture map being applied to the mesh; Step 4: Apply the grayscale texture map used for sculpting to the UV-unwrapped mesh; Step 5: Slice the mesh and establish a local coordinate system for each slice; Step 6: For each slice, generate the local coordinate system XY plane of the slice. This XY plane is the working plane of the laser galvanometer. Project the graphic corresponding to the gray level of the layer to be etched in the grayscale image on the triangle inside the slice onto the working plane of the slice along the Z-axis of the local coordinate system of the slice to obtain the projected graphic. Step 7: For each slice, generate five-axis motion mechanism positioning point data based on the center point and normal direction of the working plane corresponding to the slice, and generate laser galvanometer scanning path data based on the projection graphic obtained by projecting the graphic to be processed on the slice along the Z-axis of the local coordinate system of the slice onto the working plane of the slice. Step 8: Based on the number of engraving layers, take several gray levels in the grayscale image as one engraving layer. For each engraving layer in the grayscale image, repeat steps 5-7 to generate the five-axis motion mechanism positioning point data and laser galvanometer scanning path data corresponding to each slice of each engraving layer. In step 5, the local coordinate system of the slice is defined by the positive Z-axis direction of the normal to the base of the smallest cuboid bounding box of the triangle within the slice, which is opposite to the outer surface of the slice. The positive Y-axis direction is defined by the projection vector of the Z-axis of the world coordinate system onto the base. The X-axis direction is determined according to the right-hand rule. The axis-aligned bounding box of the triangle within the slice in the XYZ axis directions of the slice's local coordinate system established above is the axis-aligned smallest bounding box of the slice, and the center point of this bounding box is the origin of the slice's local coordinate system. When the Z-axis of the world coordinate system is perpendicular to the bottom face of the smallest cuboid bounding box of the triangle inside the slice, which is opposite to the outer surface of the slice, the positive direction of the Y-axis of the world coordinate system is taken as the positive direction of the Y-axis of the local coordinate system of the slice.

2. According to the data processing method for laser texture engraving of complex curved surfaces as described in claim 1, in step 5, the maximum difference in the Z coordinates of all triangles in the slice under the local coordinate system of the slice must be less than the focal depth of the laser beam output by the laser galvanometer and scanning focusing lens module to be used, the angle between the positive direction of the normal of the triangle in the slice and the positive direction of the Z axis of the local coordinate system of the slice must be less than the set threshold, and all triangles on the slice are projected parallel to the Z axis of the local coordinate system of the slice onto the XY plane of the local coordinate system of the slice, and the area occupied by the projected triangles must be within the effective scanning range of the laser galvanometer to be used.

3. The data processing method for laser texture engraving of complex curved surfaces according to claim 1, characterized in that: In step 8, the grayscale number of a single engraving layer is obtained by dividing the total grayscale number of the grayscale image by the number of engraving layers.

4. A processing method suitable for laser texture engraving on complex curved surfaces, characterized in that: The data obtained by the data processing method for laser texture engraving of complex curved surfaces according to any one of claims 1-3 is processed by using a five-axis motion mechanism in conjunction with a two-axis laser galvanometer and scanning focusing lens module to perform laser scanning processing on the surface of the workpiece to be processed.

5. The processing method for laser texture engraving of complex curved surfaces according to claim 4, characterized in that: For each slice of each layer being engraved, a five-axis motion mechanism is used. The positioning point data of the five-axis motion mechanism generated in step 7 is used to position the laser galvanometer and scanning focusing lens module to align with the origin of the local coordinate system of the slice. The normal direction at the center of the scanning focusing lens is made to coincide with the Z-axis direction of the local coordinate system of the slice, and the distance from the scanning focusing lens to the working plane of the slice is equal to the laser processing focal length, so that the laser beam can be focused on the working plane of the slice. Then, the scanning action of the laser galvanometer is used to perform scanning processing according to the laser galvanometer scanning path data generated in step 7.

6. The processing method for laser texture engraving of complex curved surfaces according to claim 5, characterized in that: By traversing and processing each slice of each layer, the laser texture engraving process is completed on the entire surface of the workpiece.

7. A storage medium, characterized in that: The storage uses a data processing program designed according to any one of claims 1-3, which is suitable for laser texture engraving of complex curved surfaces. The data processing program is used to generate laser galvanometer scanning path data and five-axis motion mechanism positioning point data.

8. A data processing apparatus, characterized in that: The device includes a memory and a processor. The memory stores a data processing method for laser texture engraving of complex curved surfaces as described in any one of claims 1-3. The processor runs a data processing program and outputs generated laser galvanometer scanning path data and five-axis motion mechanism positioning point data.

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