Aviation part sample plate manufacturing method based on reverse scanning and 3D printing

Abstract

The invention relates to the technical field of aviation process equipment, in particular to an aviation part sample plate manufacturing method based on reverse scanning and 3D printing. According to the technical scheme, the aviation part sample plate manufacturing method based on reverse scanning and 3D printing comprises the following steps that S1, three-dimensional data collection and preprocessing are carried out, specifically, three-dimensional reverse scanning is carried out on the object surface of a target aviation part, and three-dimensional point cloud data of the object surface are obtained; before scanning, carrying out powder spraying treatment on a highly reflective or transparent area on the surface of the real object so as to ensure the integrity of scanning data; s2, real surveying and mapping model reconstruction and optimization: processing the three-dimensional point cloud data, reconstructing a real surveying and mapping three-dimensional model of the aviation component, and performing hole repair and fairing optimization on the model. The technical means of obtaining the real appearance by reversely scanning the real object and reconstructing the theoretical model according to the drawing and carrying out fitting correction are realized, the generated composite three-dimensional model ensures the accuracy.

Description

Technical Field

[0001] This invention relates to the field of aerospace manufacturing equipment technology, and in particular to a method for manufacturing aerospace component prototypes based on reverse scanning and 3D printing. Background Technology

[0002] In the field of aerospace manufacturing, especially in the production and maintenance of older aircraft models, the assembly of complex curved surface components such as engine casings and finned plates relies heavily on physical templates for scribing and drilling. Taking the Y5B-W2 aircraft as an example, its original three-dimensional digital model is missing, and for a long time, it has relied solely on metal templates made by workers. These traditional templates have been severely worn and deformed after long-term use, and their accuracy cannot be verified due to the lack of original drawings. When production requires copying or updating templates, it can only be done through physical prototyping or manual repair, a process that is lengthy, costly, and heavily dependent on the personal experience of the operators. This directly leads to poor coordination between components such as engine casings and finned plates during assembly, and the inability to guarantee the accuracy of scribing and drilling, becoming a technical bottleneck restricting production efficiency and product quality improvement. The core problem with existing technology lies in the lack of a digital design and manufacturing method for templates that can respond quickly and accurately reflect the actual contours of components.

[0003] Existing technologies suffer from problems such as poor assembly coordination, long replication cycles, high costs, and inability to guarantee accuracy due to reliance on worn physical templates and traditional manual manufacturing methods. Summary of the Invention

[0004] This invention proposes a method for manufacturing aircraft component templates based on reverse scanning and 3D printing, which solves the problems of poor assembly coordination, long replication cycle, high cost and inability to guarantee accuracy caused by relying on physical templates that are subject to wear and tear and traditional manual manufacturing methods in the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for fabricating aircraft component prototypes based on reverse scanning and 3D printing includes the following steps: S1. 3D Data Acquisition and Preprocessing: Perform 3D reverse scanning on the physical surface of the target aerospace component to obtain its 3D point cloud data; before scanning, spray powder on the highly reflective or transparent areas of the physical surface to ensure the integrity of the scan data; S2. Measured Mapping Model Reconstruction and Optimization: The three-dimensional point cloud data is processed to reconstruct the measured three-dimensional model of the aviation component, and the model is repaired for holes and smoothed. S3. Theoretical Model Construction and Key Feature Extraction: Based on the two-dimensional design drawings of the aerospace component, construct its theoretical three-dimensional digital model and extract the key theoretical positioning features from the model; S4. Model Fitting and Accuracy Verification Based on Key Features: Using the key theoretical positioning features extracted in step S3 as a benchmark, the actual measured 3D model and the theoretical 3D digital model are fitted and matched to generate a composite 3D model that integrates the actual shape and theoretical design; then, the deviation distribution of the two models in non-key areas is calculated, and a deviation chromatogram is generated for visualization verification. S5. Template Structural Design and Lightweighting: Based on the composite 3D model, the base surface of the template is generated by surface offset, and the non-critical areas of the template are hollowed out and lightweighted while ensuring structural strength; at the same time, positioning holes, hole-making guide structures and scribing contours are integrated into the template. S6. Assembly-oriented 3D printing and post-processing: The 3D digital model of the template is sliced ​​and a support structure is generated. The template is printed using 3D printing material with good isotropic properties. After printing, the support structure is removed and the working surface of the template is precision machined to ensure its fit with the surface of the aerospace component.

[0006] Furthermore, in step S1, the powder spraying process uses a uniformly covered matte white developer; the three-dimensional reverse scanning is accomplished by moving a handheld laser scanner around the component and automatically stitching together multi-view scan data based on markers pasted on the surface of the component.

[0007] Furthermore, in step S3, the key theoretical positioning features include, but are not limited to, the theoretical axis, the center of the theoretical positioning hole, the boundary line of the theoretical card plate, or the theoretical symmetry plane on the aircraft component.

[0008] Furthermore, in step S4, the fitting and matching adopts the iterative nearest point algorithm and sets a convergence threshold; during the visualization verification process, if a local deviation is found to exceed the limit, the corresponding area of ​​the actual measurement model is corrected by local deformation based on the theoretical model, rather than by overall scaling.

[0009] Furthermore, in step S5, the hollow lightweight design adopts a honeycomb or grid-like support rib structure; the hole-making guide structure is a stepped hole with a metal bushing, and the inner hole accuracy of the metal bushing is higher than the accuracy that the 3D printing material itself can achieve.

[0010] Furthermore, in step S5, when performing surface offset, a variable gap offset algorithm is adopted for areas with large curvature changes in the aerospace component. That is, the offset gap is reduced in areas with small curvature radius and increased in areas with large curvature radius to compensate for the shrinkage and deformation of the printing material and ensure the consistency of the final template surface.

[0011] Furthermore, in step S6, the 3D printing material with good isotropic properties is a polycarbonate material whose internal stress is eliminated through a specific heat treatment process, or a photosensitive resin material with stable properties after secondary curing.

[0012] Furthermore, in step S6, the finishing process includes grinding and polishing the working surface of the template, and using a digital gap gauge to detect the gap between it and the actual aerospace component, ensuring that the gap is uniform and less than a preset value.

[0013] Furthermore, after step S6, step S7 is also included: associating the digital archive with the physical identifier; packaging the composite 3D model, the template digital model, the printing parameters, and the accuracy verification report into a digital archive and uploading it to the server; at the same time, creating an identifier containing a website link or QR code on the physical template, which can be scanned to access the digital archive.

[0014] Furthermore, the digital archive is linked to the aircraft type, sortie number, and part number information. When parts of different sorties of the same aircraft type need to be remade due to wear and tear, the archive is retrieved as a reference, and only local adaptive corrections are needed to generate a digital model of the new sortie's template.

[0015] The positive effects of this invention are: By combining reverse scanning of the physical object to obtain its true shape with reconstructing the theoretical model based on drawings and then fitting and correcting it, the generated composite 3D model effectively compensates for errors caused by the manufacturing tolerances of the component itself and the wear of the template. The template manufactured based on this model closely matches the actual contour of the component, fundamentally solving the problem of poor assembly coordination and significantly improving the accuracy of scribing and hole making.

[0016] The traditional process of machining and manually repairing metal prototypes, which takes weeks or months, has been transformed into a digital scanning, modeling, and 3D printing process that takes hours or days. This avoids expensive metal materials and complex machining, allowing for rapid prototyping using inexpensive plastic or resin materials, resulting in fast response times and significantly reduced overall costs.

[0017] One of the core achievements of this invention is the creation of a precise three-dimensional digital model of the template. This model can be permanently archived, accessed at any time, and quickly modified. This completely changes the reliance on a single physical template and solves the dilemma of "no map to follow." By linking the digital model with the physical template, traceability of information such as template version and usage records is achieved, laying a solid foundation for knowledge transfer and quality management.

[0018] The digital design stage can flexibly integrate multiple functions such as positioning, hole making, and scribing. By designing structures such as embedded metal bushings, the overall molding advantages of 3D printing are cleverly combined with the high wear resistance of metal materials, which specifically solves the pain point of easy wear of guide holes in plastic templates and extends the service life of templates. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Example A method for fabricating aircraft component prototypes based on reverse scanning and 3D printing includes the following steps: S1. 3D Data Acquisition and Preprocessing: Perform 3D reverse scanning on the physical surface of the target aerospace component to obtain its 3D point cloud data; before scanning, spray powder on the highly reflective or transparent areas of the physical surface to ensure the integrity of the scan data; S2. Measured Mapping Model Reconstruction and Optimization: The three-dimensional point cloud data is processed to reconstruct the measured three-dimensional model of the aviation component, and the model is repaired for holes and smoothed. S3. Theoretical Model Construction and Key Feature Extraction: Based on the two-dimensional design drawings of the aerospace component, construct its theoretical three-dimensional digital model and extract the key theoretical positioning features from the model; S4. Model Fitting and Accuracy Verification Based on Key Features: Using the key theoretical positioning features extracted in step S3 as a benchmark, the actual measured 3D model and the theoretical 3D digital model are fitted and matched to generate a composite 3D model that integrates the actual shape and theoretical design; then, the deviation distribution of the two models in non-key areas is calculated, and a deviation chromatogram is generated for visualization verification. S5. Template Structural Design and Lightweighting: Based on the composite 3D model, the base surface of the template is generated by surface offset, and the non-critical areas of the template are hollowed out and lightweighted while ensuring structural strength; at the same time, positioning holes, hole-making guide structures and scribing contours are integrated into the template. S6. Assembly-oriented 3D printing and post-processing: The 3D digital model of the template is sliced ​​and a support structure is generated. The template is printed using 3D printing material with good isotropic properties. After printing, the support structure is removed and the working surface of the template is precision machined to ensure its fit with the surface of the aerospace component.

[0021] This method begins with preprocessing and acquiring 3D data of the actual surface of the target aerospace component (such as an aircraft engine casing). Since the surface of the aerospace component may have highly reflective areas that interfere with optical scanning, a uniform layer of matte white developer is sprayed first to obtain complete, high-quality 3D point cloud data. Next, in reverse engineering software, the acquired point cloud data is denoised, simplified, and encapsulated to reconstruct a 3D model (actual measurement model) that accurately reflects the actual manufacturing state of the component. Simultaneously, based on the component's 2D design drawings, its theoretical shape is accurately reconstructed in CAD software, generating a theoretical 3D digital model. The core step is to fit these two models together, aligning them in the same coordinate system using a best-fit algorithm (such as the iterative nearest-point algorithm) to generate a composite 3D model that includes both real-world details and theoretical dimensions. This process effectively compensates for manufacturing tolerances. Based on this composite model, a template is digitally designed: first, the model surface is offset by a preset gap to generate the template's base surface; then, functional structures such as positioning pin holes and drilling guide holes are integrated onto this base. Finally, the designed 3D model is sliced ​​and imported into a 3D printer. Appropriate material parameters are selected to create a physical template in one step. After printing, the supports need to be removed and the surface is finely machined to ensure a perfect fit with the surface of the part.

[0022] In step S1, the powder spraying process uses a uniformly covered matte white developer; the three-dimensional reverse scanning is accomplished by moving a handheld laser scanner around the component and automatically stitching together multi-view scan data based on markers pasted on the surface of the component.

[0023] During the scanning process, a handheld laser scanner measures distance by projecting a laser beam and capturing its deformation. To achieve complete scanning of large components and ensure global accuracy, multiple reference markers are pre-attached to the surface of the component and surrounding fixtures. During the scanning process, the equipment continuously identifies these markers and, based on them, automatically and accurately stitches together multiple local scan fragments obtained by the operator from different angles and positions into a complete and seamless 3D point cloud dataset in real time.

[0024] In step S3, the key theoretical positioning features include, but are not limited to, the theoretical axis, the center of the theoretical positioning hole, the boundary line of the theoretical card plate, or the theoretical symmetry plane on the aircraft component.

[0025] After the theoretical model is built, it is necessary to identify and extract the geometric features that are crucial for assembly positioning. These features are usually clearly defined by the design drawings, such as the main theoretical axes of the component, the center points of the positioning holes that serve as process references, the theoretical clamping lines used to define the installation boundaries, or the theoretical planes of symmetry of the component. In CAD software, these features can be directly selected and defined from the model's sketches, reference planes, or solid edges, providing precise and engineering-compliant constraints for subsequent fitting operations.

[0026] In step S4, the fitting and matching adopts the iterative nearest point algorithm and sets a convergence threshold; during the visualization verification process, if a local deviation is found to exceed the limit, the corresponding area of ​​the actual measurement model is first corrected by local deformation based on the theoretical model, rather than by overall scaling.

[0027] Model fitting is performed in dedicated inspection or reverse engineering software. The software utilizes algorithms such as iterative nearest point calculations to continuously adjust the model position through multiple iterations, minimizing the average distance between corresponding points and achieving high-precision alignment. After alignment, the software generates a color deviation chromatogram, visually displaying the differences between the measured model and the theoretical model at various points. If abnormal deviations are found in local areas, operators use the software's local editing tools to make small adjustments to the triangular faces of the measured model, using the theoretical model as an immutable reference. This local correction method effectively eliminates abnormal points caused by local wear or scanning errors without damaging the overall model shape.

[0028] In step S5, the hollow lightweight design adopts a honeycomb or grid-like support rib structure; the hole-making guide structure is a stepped hole with a metal bushing, and the inner hole precision of the metal bushing is higher than the precision that the 3D printing material itself can achieve.

[0029] After completing the basic shape design of the prototype, to reduce weight and save materials, hollowing-out designs are made in non-critical load-bearing areas of the prototype body (such as the large central panel). This design is not a simple hollowing out, but rather the construction of regular honeycomb or grid-like supporting ribs to maintain sufficient overall rigidity. For frequently used hole-making guide parts, a stepped hole structure is designed. After printing, pre-processed metal bushings with extremely high internal hole precision (such as bearing steel sleeves) are pressed into these stepped holes. In this way, the precision and wear resistance of the guide holes are guaranteed by the metal bushings, while the complex overall structure of the prototype is efficiently formed by 3D printing, combining the advantages of both manufacturing technologies.

[0030] In step S5, when performing surface offset, for areas with large curvature changes in the aerospace component, a variable gap offset algorithm is adopted. That is, the offset gap is reduced in areas with small curvature radius and increased in areas with large curvature radius to compensate for the shrinkage and deformation of the printing material and ensure the consistency of the final template surface.

[0031] When generating the template surface through surface offsetting, a variable gap strategy is employed. First, the software analyzes the curvature distribution of the composite model surface. In curved areas with greater curvature (where the shrinkage effect is more pronounced during material printing and cooling), the system automatically uses a smaller offset gap; in flat areas with less curvature, a larger offset gap is used. This dynamic adjustment aims to pre-compensate for shape-related non-uniform shrinkage deformation that may occur during printing, thereby ensuring that the final printed template surface maintains a uniform and consistent fit with the actual part surface after cooling and solidification.

[0032] In step S6, the 3D printing material with good isotropic properties is a polycarbonate material whose internal stress is eliminated through a specific heat treatment process, or a photosensitive resin material with stable properties after secondary curing.

[0033] When selecting 3D printing materials, the stability of their post-printing properties is a key consideration. For engineering plastics like polycarbonate, the printed prototypes require annealing heat treatment. This involves placing the prototype in an oven and slowly heating it to a specific temperature, holding it there for a period of time to effectively eliminate internal stress generated during printing, ensuring uniform shrinkage and improving the long-term dimensional stability of the prototype. For photosensitive resin materials, the printed prototypes need to undergo thorough secondary curing under specific wavelengths of ultraviolet light to ensure complete cross-linking of the resin, achieving the desired mechanical and chemical stability.

[0034] In step S6, the finishing process includes grinding and polishing the working surface of the template, and using a digital gap gauge to detect the gap between it and the actual aerospace component to ensure that the gap is uniform and less than a preset value.

[0035] After the template is removed from the printer, its supporting structure is carefully removed first. Then, its working surfaces (i.e., the surfaces in contact with the aircraft skin) are carefully sanded and polished manually or mechanically using progressively finer sandpaper to completely eliminate printing marks and surface imperfections. After sanding, a digital gap gauge is used for inspection: the template is positioned on the actual part, and the gap gauge probe is used to measure the gap between the template and the skin at multiple preset testing points. This ensures that the gap values ​​at all measuring points are uniform and meet assembly process requirements; this is a crucial quality control step to guarantee the template's accuracy.

[0036] Following step S6, step S7 is also included: associating the digital archive with the physical identifier; packaging the composite 3D model, the template digital model, the printing parameters, and the accuracy verification report into a digital archive and uploading it to the server; simultaneously, creating an identifier containing a website link or QR code on the physical template, which can be scanned to access the digital archive.

[0037] After the entire prototype manufacturing process is completed, all key digital data generated throughout the process, including the final 3D model of the prototype used for printing, the composite 3D model generated after fitting, key printing parameter settings records, and accuracy inspection reports, are integrated into a complete digital data package and archived in the product data management system. Simultaneously, a label containing a unique number or QR code is created and securely attached to the non-working surface of the physical prototype. By scanning this QR code, the corresponding digital file stored in the cloud can be directly accessed on a terminal device, enabling two-way association and traceability between the physical prototype and its entire lifecycle digital information.

[0038] The digital archive is linked to the aircraft type, sortie, and part number information. When parts of different sorties of the same aircraft type need to be remade due to wear and tear, the archive is retrieved as a reference. Only local adaptive corrections are needed to the new scanned model to generate a digital model of the new sortie.

[0039] When it is necessary to create prototypes of the same parts for a new production run of the same aircraft model (e.g., aircraft 1303), the data foundation established for aircraft 1302 can be utilized. Operators retrieve the complete digital archive corresponding to aircraft 1302 from the PDM system, using its theoretical model and prototype design logic as a benchmark. Then, only the new point cloud data obtained from scanning the parts of aircraft 1303 is processed, and it is fitted to the theoretical model in the archive. The software highlights local differences in the new parts caused by production deviations or wear. Designers only need to make targeted model adjustments to these local areas to quickly derive a prototype digital model suitable for the new run, eliminating the need to design from scratch and achieving efficient knowledge reuse and rapid response.

[0040] The above-described embodiments are detailed and specific, illustrating preferred embodiments of the present invention. They are only used to illustrate the technical ideas and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. However, they are not limited to the present invention, and the patent scope of the present invention cannot be limited by this embodiment alone. That is, any equivalent changes or modifications made to the spirit disclosed in the present invention, without departing from the structure of the present invention, such as local improvements within the system and modifications or transformations between subsystems, are still within the patent scope of the present invention.

Claims

1. A method for making an aeronautical part template based on reverse scanning and 3D printing, characterized in that, The method comprises the following steps: S1. Three-dimensional data acquisition and preprocessing: three-dimensional reverse scanning is performed on the physical surface of the target aircraft component to obtain three-dimensional point cloud data; before scanning, the high-reflective or transparent areas of the physical surface are treated with powder spraying to ensure the integrity of the scanning data; S2. Measured drawing model reconstruction and optimization: the three-dimensional point cloud data is processed to reconstruct the measured drawing three-dimensional model of the aircraft component, and the model is repaired and smoothed for optimization; S3. Theoretical model construction and key feature extraction: according to the two-dimensional design drawings of the aircraft component, a theoretical three-dimensional digital model is constructed, and key theoretical positioning features are extracted from the model; S4. Model fitting and accuracy verification based on key features: taking the key theoretical positioning features extracted in step S3 as the reference, the measured drawing three-dimensional model is fitted and matched with the theoretical three-dimensional digital model to generate a composite three-dimensional model that combines the actual shape and the theoretical design; then, the deviation distribution of the two models in the non-key area is calculated, and a deviation chromatogram is generated for visual verification; S5. Structure design and lightweight of the template: based on the composite three-dimensional model, the base surface of the template is generated by surface offset, and the non-key area of the template is designed to be hollow and lightweight under the premise of ensuring the structural strength; meanwhile, positioning holes, hole guide structures and scribing contours are integrated on the template; S6. 3D printing and post-processing for assembly: the three-dimensional digital model of the template is sliced and support structures are generated, and a 3D printing material with good isotropic performance is used for printing; After printing, the support structures are removed, and the working surface of the template is finished to ensure its fit with the surface of the aircraft component.

2. The method according to claim 1, wherein, In step S1, the powder spraying treatment uses uniform coverage of matte white developer; the three-dimensional reverse scanning is completed by moving a handheld laser scanner around the component and automatically splicing multi-view scanning data based on the marker points pasted on the surface of the component.

3. The method of claim 1, wherein, In step S3, the key theoretical positioning features include but are not limited to theoretical axes, theoretical positioning hole centers, theoretical card plate boundary lines or theoretical symmetry planes on the aircraft component.

4. The method of claim 1, wherein, In step S4, the fitting and matching use the iterative closest point algorithm with a convergence threshold; in the visual verification process, if local deviation is found to be out of limit, the corresponding area of the measured drawing model is preferentially deformed and corrected based on the theoretical model, rather than being scaled globally.

5. The method of claim 1, wherein, In step S5, the hollow lightweight design uses a honeycomb or grid support rib structure; the hole guide structure is a stepped hole with a metal bushing, and the inner hole accuracy of the metal bushing is higher than that of the 3D printing material itself.

6. The method of claim 1, wherein, In step S5, when performing surface offset, for the areas with large curvature changes of the aircraft component, a variable gap offset algorithm is used, i.e. the offset gap is reduced in areas with small curvature radius and increased in areas with large curvature radius, to compensate for the shrinkage and deformation of the printing material and ensure the fit consistency of the final template surface.

7. The method of claim 1, wherein, In step S6, the isotropic 3D printing material is a polycarbonate material with internal stress eliminated by a heat treatment process, or a photosensitive resin material with stable performance after secondary curing.

8. The method of claim 1, wherein, In step S6, the finishing includes polishing and polishing the sample working profile, and using a digital gap gauge to detect the gap between the sample working profile and the actual aircraft part, to ensure that the gap is uniform and less than a preset value.

9. The method according to any one of claims 1 to 8, characterized in that, After step S6, step S7 is further included: associating the digital file with the physical identification; packaging the composite three-dimensional model, the sample digital model, the printing parameters, and the precision verification report to generate a digital file, and uploading the digital file to a server; at the same time, an identification plate containing a website link or a two-dimensional code is made on the physical sample, and the digital file can be accessed by scanning the identification plate.

10. The method of claim 9, wherein, The digital file is bound with the aircraft model, the number of flights, and the part number information. When the parts of the same model but different flights need to be re-made due to wear, the file is called as a reference, and only local adaptive correction needs to be made on the new scanned model to generate a sample digital model of the new flight.