A curved surface layered 3D printing path planning method and system

Abstract

The present application belongs to the technical field of 3D printing pre-treatment, and provides a curved surface layering 3D printing path planning method and system, specifically comprising: three-dimensional modeling of a printed component with a curved surface structure; obtaining a triangular facet file of the curved surface structure model; analyzing the triangular facet coordinates of the triangular facet (STL) file; performing projection transformation on the curved surface structure model to realize three-dimensional entity transformation of the model; performing path planning of the three-dimensional entity in the transformed three-dimensional entity model using a traditional plane layering algorithm; and inversely transforming the three-dimensional entity model after path planning using the plane layering algorithm into the original three-dimensional entity structure to complete curved surface path planning. The present application effectively solves the problem that part construction can only be printed in a fixed single direction when layering a plane, improves the mechanical properties of the part, and solves the problem that the strength cannot be satisfied when layering a plane to manufacture thin-walled, micro-curved (shell type) and other components with bending characteristics.

Description

Technical Field

[0001] This invention belongs to the field of 3D printing pre-processing technology, and particularly relates to a method and system for path planning in curved surface layering 3D printing. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Currently, traditional manufacturing technologies generally suffer from problems such as poor working environment, numerous and complex processes, long mold manufacturing cycle, difficulty in component iteration, and high cost of small-batch processing.

[0004] Additive manufacturing technology, as an advanced manufacturing technology different from traditional manufacturing technology, does not require the pre-processing of product molds. It can directly print three-dimensional CAD data into three-dimensional model components using a 3D printer. Compared with traditional manufacturing methods, it has many advantages such as shorter production cycle and lower economic cost for small-batch production.

[0005] Currently, planar layered manufacturing in additive manufacturing is widely used in 3D printing due to its simple process and ease of manufacturing, and the technology is more mature.

[0006] Planar layer-by-layer manufacturing involves stacking materials layer by layer in a single direction on a flat surface using a printer nozzle to form printed components. However, because of this unidirectional layer-by-layer stacking, the printing filament becomes discontinuous and interrupted. When printing thin-section, slightly curved (shell-shaped) components, the strength of the printed components decreases, or even printing fails, which greatly hinders the development of 3D printing. For example, in the field of continuous fiber composite material 3D printing, planar layer-by-layer manufacturing makes it difficult for continuous fibers to be freely distributed on curved surfaces, making continuous and controllable laying impossible and greatly reducing the strength of continuous fiber composite material components. In the field of micro-nano additive manufacturing circuit 3D printing, the results of planar layer-by-layer printing are often unsatisfactory when printing some small non-planar structures. When printing curved plastic parts such as conductive electronic tracks on circuit boards, planar layer-by-layer manufacturing causes the continuity of the circuit to be interrupted in the middle of the layers, seriously affecting the printing results.

[0007] Meanwhile, because planar layer-by-layer manufacturing stacks components in a single direction, the final printed component may have poor surface finish and exhibit a "staircase effect." This "staircase effect" is particularly pronounced when printing curved or thin-shell structures, resulting in poor surface quality, low processing efficiency, and failure to meet strength requirements, leading to warping and deformation. This makes planar layer-by-layer manufacturing less effective for printing curved structures. Summary of the Invention

[0008] To address at least one of the technical problems mentioned above, this invention provides a path planning method and system for curved surface layered 3D printing. This method can directly plan paths based on curved surface structures, solving problems such as the difficulty of freely distributing continuous fibers on spatial curved surfaces. It enables controllable distribution printing of continuous fiber composite materials on curved surfaces and provides a good solution for controllable circuit printing on curved surface structures. At the same time, it solves problems such as poor surface finish and "step effect" in planar layered printing, reduced strength of printed components, and warping deformation during printing.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] The first aspect of this invention provides a path planning method for layered 3D printing of curved surfaces, comprising the following steps:

[0011] Perform 3D modeling on the component with curved surface structure to be printed, and generate a 3D solid model of the corresponding component;

[0012] The coordinates of the triangular facet points are obtained by analyzing the three-dimensional solid model of the component;

[0013] Based on the structure of the component to be printed, the corresponding projection transformation rules are adopted, and the surface is discretized into points according to the coordinates of the triangular facet points. The spatial projection transformation is then performed on the three-dimensional solid model of the component to obtain the transformed three-dimensional solid model.

[0014] The transformed 3D solid model is sliced ​​and path planned in layers. The 3D solid model after path planning is then transformed back into the original 3D solid structure to generate a surface printing path.

[0015] A second aspect of the present invention provides a path planning system for surface layering 3D printing, comprising:

[0016] The 3D modeling module is used to perform 3D modeling of components with curved surface structures to be printed, generating 3D solid models of the corresponding components.

[0017] The 3D solid model parsing module is used to parse the 3D solid model of a component to obtain the coordinates of triangular facet points;

[0018] The projection transformation module is used to discretize the surface into points based on the coordinates of the triangular facet points according to the structure of the component to be printed, and to perform spatial projection transformation on the three-dimensional solid model of the component to obtain the transformed three-dimensional solid model.

[0019] The printing path planning module is used to perform layer slicing and path planning on the transformed 3D solid model, and then transform the 3D solid model after path planning back into the original 3D solid structure to generate a curved printing path.

[0020] A third aspect of the present invention provides a computer-readable storage medium.

[0021] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the surface layering 3D printing path planning method described above.

[0022] A fourth aspect of the present invention provides a computer device.

[0023] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the surface layering 3D printing path planning method described above.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. The present invention adopts a curved surface layering method to effectively solve the problem that the part can only be printed along a fixed single direction when the planar layering is used, thereby improving the mechanical properties of the part. It also solves the problem that the strength cannot be met when manufacturing thin-section, slightly curved (shell-shaped) parts by planar layering, and further improves the mechanical properties of 3D printed curved surface structures.

[0026] 2. This invention can directly plan the path according to the curved surface structure, which solves the problem that continuous fibers are difficult to distribute freely on the spatial curved surface, realizes the controllable distribution printing of continuous fiber composite materials on the curved surface, and also provides a good solution for controllable printing of circuits on curved surface structures; and solves the problems of poor surface finish and "step effect" in planar layered printing, reduced strength of printed components, and warping deformation during printing.

[0027] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] Figure 1 This is a flowchart of the path planning method for 3D printing of curved structures according to Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the projection transformation from a specified curved surface to an arbitrary given plane for a curved thin-shell structure according to Embodiment 1 of the present invention;

[0031] Figure 3This is a schematic diagram of the path planning of the curved thin shell structure in any given plane according to Embodiment 1 of the present invention;

[0032] Figure 4 This is a three-dimensional schematic diagram of the curved surface non-thin shell structure model of Embodiment 2 of the present invention;

[0033] Figure 5 This is a frontal view of the projection transformation of the curved surface non-thin shell structure model in Embodiment 2 of the present invention;

[0034] Figure 6 This is a three-dimensional transformation diagram of the curved surface non-thin shell structure model of Embodiment 2 of the present invention. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0036] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] Terminology Explanation

[0039] STL (STereolithography) is a file format created by 3D Systems Software Corporation, originally intended for stereolithography computer-aided design software. It has some hindsight-related acronyms such as "Standard Triangle Language," "Standard Tessellation Language," "STereolithography Language," and "(Stereolithography Tessellation Language)." Many software packages support this format, and it is widely used in rapid prototyping, 3D printing, and computer-aided manufacturing (CAM). STL files only describe the surface geometry of a 3D object, without color, material maps, or other common 3D model attributes. The STL format has both text and binary formats. The text format is more common due to its superior readability and direct readability.

[0040] An STL file describes a raw, unstructured triangular mesh in a 3D triangular Cartesian coordinate system, consisting of surface unit normals and vertices ordered by the right-hand rule. STL coordinates must be positive numbers, have no scale information, and can be in any unit of measurement.

[0041] As mentioned in the background section of this invention, the existing technology of printing curved structures exhibits a "step effect" during planar layered manufacturing, resulting in poor printed surface quality, low processing efficiency, warping deformation, and problems in improving the mechanical properties of printed components.

[0042] This invention provides a path planning method for surface layering 3D printing. It involves creating a 3D model of the component to be printed, generating an STL model of the component, resolving the coordinates of triangular facet points from the STL model, selecting a 3D solid with a curved surface structure for projection transformation, and performing a 3D solid transformation based on the projection transformation rules. Path planning is then performed on the transformed 3D solid model using a traditional planar layering and slicing algorithm. Finally, the 3D solid model with the path planning completed using the traditional planar layering algorithm is inversely transformed back to the original 3D solid structure to complete the path planning for the curved surface structure. This provides a method and approach for the future development of additive manufacturing 3D printing technology for curved surface structures.

[0043] Example 1

[0044] Reference Figure 1 This embodiment provides a path planning method for layered 3D printing of curved surfaces, including the following steps:

[0045] The component with a curved structure to be printed in this embodiment can be a curved thin-shell component or a non-thin-shell component with a curved structure.

[0046] When the curved surface structure to be printed is a thin-shell curved surface, the 3D printing path planning method specifically includes the following steps:

[0047] S1: Perform 3D modeling on the curved thin-shell component to be printed, and generate a 3D solid model of the corresponding component;

[0048] In S1, computer-aided design (CAD) software can be used to create 3D models of curved surface structural components to be printed; such as Autodesk Inventor, SolidWorks, ZW3D, CATIA, Pro / E, Onespace, AutoCAD, or UG NX.

[0049] like Figure 2 As shown, this is a 3D model of the curved surface structure component to be printed.

[0050] S2: Analyze the three-dimensional solid model of the component to obtain the coordinates of the triangular facet points;

[0051] The surface structure model generated by S1 in CAD software is imported into computer-aided manufacturing (CAM) software with the function of exporting model STL files to generate STL triangular facet files through triangular facet slicing.

[0052] For example, UG NX, Pro / NC, CATIA, MasterCAM, SurfCAM, SPACE-E, CAMWORKS, WorkNC, TEBIS, HyperMILL, Powermill, Gibbs CAM, FEATURECAM, topsolid, solidcam, cimatron, vx, esprit, gibbscam or Edgecam, etc.

[0053] S3: Parse the STL file to obtain the coordinates of each point on the surface triangle patch;

[0054] The three-dimensional model of the curved surface structure of the component is sliced ​​into triangular facets and exported to generate an STL file. The coordinates of each triangular facet are then obtained by parsing.

[0055] S4: Based on the structure of the component to be printed, the corresponding projection transformation rules are adopted, and the surface is discretized into points according to the coordinates of the triangular facet points. The spatial projection transformation of the three-dimensional solid model of the component is then performed to obtain the transformed three-dimensional solid model.

[0056] In this embodiment, the three-dimensional solid transformation of the model can be realized according to certain projection transformation rules; the projection transformation can be carried out by selecting appropriate projection transformation rules according to the specific printing structure.

[0057] For example, in this embodiment, for a model with a curved surface structure, the curved surface structure triangle patch (STL) file is obtained through the above steps S1, S2 and S3, and the coordinate values ​​of each curved surface triangle patch are obtained by parsing.

[0058] The process involves employing corresponding projection transformation rules to discretize the surface into points based on the coordinates of triangular facet points, and then performing a spatial projection transformation on the three-dimensional solid model of the component. Specifically, this includes:

[0059] S401: As Figure 3 As shown, the coordinate values ​​of the obtained curved triangular facets are projected onto a given arbitrary plane (AX+BY+CZ+D=0) using vertical projection (parallel to the coordinate axes);

[0060] S402: Set the coordinates on the 3D solid model of the component to be printed. Projecting coordinates onto this plane

[0061] S403: Calculate the normal vector of the plane. Right now And calculate the distance from any point on the surface structure model to the given plane.

[0062] S404: Calculate the normal vector of the plane, and then calculate the vector from a point on the surface structure model to a given arbitrary plane and the distance between the two points to obtain the projected coordinate values;

[0063] The coordinates P on the printed component are obtained based on the normal vector of this plane. i Its projection onto the plane P j The vector is It can be solved According to the formula for distance between two points The conclusion is

[0064] Finally, the projected coordinate values ​​of the curved surface can be obtained.

[0065] Based on this projection rule, the curved surface structure model is transformed into a three-dimensional solid model through three-dimensional projection.

[0066] It should be noted that the projection transformation rules are not unique, and different transformation rules should be adopted according to the 3D solid model to be printed to perform specific 3D solid projection transformation.

[0067] S5: Perform layer slicing and path planning on the transformed 3D solid model, and then transform the 3D solid model after path planning back into the original 3D solid structure to generate a surface printing path.

[0068] In S5, the transformed 3D solid model is sliced ​​using a traditional planar layering algorithm, or the 3D printing slice path generation software uses a traditional planar layering algorithm for path planning of the 3D solid, such as ReplicatorG, RepetierH, Cura, XBuilder, Maker Bot, Slic3r, or Simplify3D. For example, the traditional planar layering algorithm can use the Zigzag path filling algorithm for path filling, which is the most common printing method at present, and will not be elaborated here.

[0069] S6: Transform the 3D solid model after path planning using the traditional planar layering algorithm back into the original 3D solid structure to complete the path planning for the curved structure.

[0070] When the curved structural component to be printed is a curved non-thin shell structure, its 3D printing path planning method is the same as that for curved thin shell components.

[0071] It also takes a 3D model as input, exports the model as an STL file and parses the coordinates of the triangular facets. It performs a spatial projection 3D solid transformation on a non-thin shell structure model with curved surfaces through an arbitrary given projection plane. A new 3D solid model is generated through the spatial projection 3D solid transformation. Then, the traditional planar slicing algorithm is used for path planning in the transformed 3D solid model. After the path planning is completed, an inverse transformation is performed to generate the original 3D solid model to complete the printing path planning.

[0072] The specific steps are as follows:

[0073] 1) Create a 3D model of the curved non-thin shell structure to be printed. Use existing computer-aided design (CAD) software to create the 3D model of the curved non-thin shell structure as shown in the diagram. Figure 4 As shown;

[0074] 2) Export and parse the STL file of the curved non-thin shell 3D model;

[0075] 3) The three-dimensional solid structure model with a curved upper surface is transformed into a three-dimensional solid structure model with a planar upper surface through spatial projection three-dimensional solid transformation. The corresponding transformation process is shown in the diagram. Figure 5 As shown, the transformed three-dimensional entity is illustrated in the diagram. Figure 6 As shown;

[0076] 4) In the transformed 3D solid model, the traditional planar layering algorithm is used for slicing and path planning;

[0077] 5) Perform an inverse transformation on the 3D solid model after path planning is completed, transforming it back into the original 3D solid model to complete the path planning for the curved structure.

[0078] The advantages of the above solution are that it enables controllable printing of curved structures, solves the "staircase effect" in 3D printing of curved structure models, improves the surface quality of printed components, and effectively solves problems such as low processing efficiency, warping deformation during printing, and insufficient strength of printed curved components when using planar layer manufacturing.

[0079] Example 2

[0080] This embodiment provides a path planning system for surface layering 3D printing, including:

[0081] The 3D modeling module is used to perform 3D modeling of components with curved surface structures to be printed, generating 3D solid models of the corresponding components.

[0082] The 3D solid model parsing module is used to parse the 3D solid model of a component to obtain the coordinates of triangular facet points;

[0083] The projection transformation module is used to discretize the surface into points based on the coordinates of the triangular facet points according to the structure of the component to be printed, and to perform spatial projection transformation on the three-dimensional solid model of the component to obtain the transformed three-dimensional solid model.

[0084] The printing path planning module is used to perform layer slicing and path planning on the transformed 3D solid model, and then transform the 3D solid model after path planning back into the original 3D solid structure to generate a curved printing path.

[0085] Example 3

[0086] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the surface layering 3D printing path planning method described above.

[0087] Example 4

[0088] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in the surface layering 3D printing path planning method described above.

[0089] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0090] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0091] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0092] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0093] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A path planning method for layered 3D printing of curved surfaces, characterized in that, Includes the following steps: Perform 3D modeling on the component with curved surface structure to be printed, and generate a 3D solid model of the corresponding component; The coordinates of the triangular facet points are obtained by analyzing the three-dimensional solid model of the component; Based on the structure of the component to be printed, the corresponding projection transformation rules are adopted, and the faces are discretized into points according to the coordinates of the triangular facets. A spatial projection transformation is then performed on the 3D solid model of the component to obtain the transformed 3D solid model. Specifically, the adoption of the corresponding projection transformation rules, discretizing the faces into points according to the coordinates of the triangular facets, and performing a spatial projection transformation on the 3D solid model of the component includes: The coordinate values ​​of the obtained curved triangular facets are projected onto a given arbitrary plane using a vertical projection parallel to the coordinate axes. The coordinates on the 3D solid model of the component to be printed are projected onto this plane to obtain the projected coordinates. Based on the projected coordinates and the normal vector of the plane, calculate the distance from any point on the 3D solid model of the component to be printed to the plane; then calculate the vector from a point on the 3D solid model of the component to be printed to a given arbitrary plane and the distance formula between the two points, and obtain the projected coordinate values; The transformed 3D solid model is sliced ​​and path planned in layers. The 3D solid model after path planning is then transformed back into the original 3D solid structure to generate a surface printing path.

2. The path planning method for layered 3D printing of curved surfaces as described in claim 1, characterized in that, After generating the 3D solid model of the corresponding component, obtain the STL file of the 3D model, and obtain the coordinates of each point of the triangular facet of the curved surface structure by parsing the STL file.

3. The method for path planning in layered 3D printing of curved surfaces as described in claim 1, characterized in that, The component to be printed, which has a curved surface structure, is either a curved thin-shell component or a non-thin-shell structure with a curved surface.

4. The method for path planning in layered 3D printing of curved surfaces as described in claim 1, characterized in that, The transformation of the 3D solid model is performed by slicing and path planning using a planar layering algorithm and a Zigzag path filling algorithm.

5. A path planning system for layered curved surface 3D printing, characterized in that, include: The 3D modeling module is used to perform 3D modeling of components with curved surface structures to be printed, generating 3D solid models of the corresponding components. The 3D solid model parsing module is used to parse the 3D solid model of a component to obtain the coordinates of triangular facet points; The projection transformation module is used to discretize the surfaces into points based on the coordinates of triangular facets according to the structure of the component to be printed, and to perform a spatial projection transformation on the 3D solid model of the component to obtain the transformed 3D solid model. Specifically, the process of discretizing the surfaces into points based on the coordinates of triangular facets and performing a spatial projection transformation on the 3D solid model of the component according to the corresponding projection transformation rules includes: The coordinate values ​​of the obtained curved triangular facets are projected onto a given arbitrary plane using a vertical projection parallel to the coordinate axes. The coordinates on the 3D solid model of the component to be printed are projected onto this plane to obtain the projected coordinates. Based on the projected coordinates and the normal vector of the plane, calculate the distance from any point on the 3D solid model of the component to be printed to the plane; then calculate the vector from a point on the 3D solid model of the component to be printed to a given arbitrary plane and the distance formula between the two points, and obtain the projected coordinate values; The printing path planning module is used to perform layer slicing and path planning on the transformed 3D solid model, and then transform the 3D solid model after path planning back into the original 3D solid structure to generate a curved printing path.

6. The path planning system for layered curved surface 3D printing as described in claim 5, characterized in that, The component to be printed, which has a curved surface structure, is either a curved thin-shell component or a non-thin-shell structure with a curved surface.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps in the surface layering 3D printing path planning method as described in any one of claims 1-4.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the surface layering 3D printing path planning method as described in any one of claims 1-4.

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