Three-dimensional part size automatic marking method and system

Abstract

The invention discloses a three-dimensional part size automatic labeling method and system. The method comprises the following steps: creating a labeling view and a labeling plane; creating a marking reference coordinate system; simplifying the model; calculating model feature boundary coordinates; model feature boundary coordinates are projected and marked; arc edge feature size processing: marking the size of the arc radius at the arc edge position; and restoring model features. The method does not depend on a machine learning algorithm, is good in practicability and universality, is simple in algorithm development, is easy to integrate into three-dimensional CAD design software, and can guarantee the rationality, completeness and clearness of a labeling result to a certain degree.

Description

Technical Field

[0001] The invention belongs to the field of automatic part dimension marking, and in particular relates to a three-dimensional part dimension automatic marking method and system. Background Art

[0002] The process from part design to processing is inseparable from the accurate and reasonable annotation of part feature dimensions. In the past, part design was done in two dimensions, and part dimensions were annotated based on two-dimensional drawings. Now, a variety of three-dimensional CAD design software provides more intuitive three-dimensional design tools for part design. The part design process has evolved into a full three-dimensional design process, and the part dimension annotation also uses full three-dimensional annotation. However, the full three-dimensional annotation of part dimensions still relies on manual annotation by designers, which is a lot of work. Statistics show that part dimension annotation accounts for more than 30% of the design workload.

[0003] If the problem of automatic dimensioning of three-dimensional parts can be solved, the efficiency of part design will be improved, the workload of designers will be reduced, and the product design cycle will be shortened. Patent CN114239169A provides an automatic dimensioning method based on key point matching, which uses artificial intelligence algorithms to perform model preprocessing, training, and recognition to achieve automatic dimensioning. This method requires manual adjustment of the algorithm, relies on a large number of data samples, and has the problem of neural overfitting, and the effect is not ideal in practical applications. The document "Overview of the Development of Three-Dimensional Dimensioning and Completeness Detection Technology" by Liu Xiaojun (2017) et al. introduces the current status of various technical research on the realization of automatic three-dimensional dimensioning. The document also points out that three-dimensional dimensioning relies on feature recognition, artificial intelligence, annotation knowledge, adjacency matrix and other technologies to produce three-dimensional dimensions that meet the standards. The standards include rationality, completeness, and clarity. Whether it is theoretical research in academia or application development in commercial systems, it is not realistic to achieve automatic dimensioning.

[0004] In summary, the existing solutions for automatic dimensioning of 3D parts have the following problems: 1) The dimensioning results are unreasonable, incomplete, and unclear; 2) The algorithm is difficult to develop and integrate into 3D CAD design software; 3) The development method based on artificial intelligence algorithm relies on a large number of data samples, and has poor practicality and versatility. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a method for automatic dimensioning of three-dimensional parts, comprising the following steps:

[0006] 1) Create annotation views and annotation planes;

[0007] 2) Create a reference coordinate system for annotation;

[0008] 3) Model simplification;

[0009] 4) Calculation of model feature boundary coordinates;

[0010] 5) Project and mark the model feature boundary coordinates;

[0011] 6) Arc edge feature size processing: mark the arc radius size at the arc edge position;

[0012] 7) Model feature restoration.

[0013] Furthermore, after the model feature restoration is performed, the redundancy check and confirmation of the annotation results are also performed.

[0014] Specifically, the creation of the annotation reference coordinate system is as follows: based on each annotation plane, an annotation reference point is selected and a reference coordinate system is created, with the horizontal direction as the X-axis and the vertical direction as the Y-axis, and all subsequent dimension annotations are performed based on the reference coordinate system.

[0015] Specifically, the model feature boundary coordinate calculation specifically includes: according to the three-dimensional model of the part, reversely traversing the model features, placing the fillet and chamfer features into the stack, and deleting the fillet and chamfer features.

[0016] Specifically, the model feature boundary coordinate calculation specifically includes: the model feature boundary is a straight edge or an arc edge, in the annotation view direction, for the intersection of the straight edge and other edges, identify the point coordinates (X1, Y1), (X2, Y2)..., and convert them into the point coordinates (X1, Y1), (X2, Y2)... in the annotation reference coordinate system. 0 1. Y 0 1) (X 0 2. Y 0 2)…; For the arc edge, identify and convert the center position coordinates.

[0017] Specifically, the model feature boundary coordinate projection and annotation specifically includes the following steps: projecting the model feature boundary coordinates onto the X-axis and Y-axis of the annotation reference coordinate system, merging the same coordinates, and annotating the model dimensions in the X-axis and Y-axis directions.

[0018] Specifically, the model feature restoration is as follows: popping the model fillet and chamfer features put into the stack, restoring the model fillet and chamfer features one by one, and marking the fillet and chamfer positions and sizes in the form of technical requirement text + color marking.

[0019] Specifically, the dimensioning results in multiple annotation views are checked for redundancy according to the annotation point path method, and the redundantly-annotated dimensions are marked. The annotation point path method specifically includes the following steps: two points in space are point A and point B. If there is a dimension from point A to point B, then it is possible to reach point B from point A along the dimensioning path; if there are multiple dimensionings between point A and point B, then there are multiple paths from point A to point B; the criterion for determining whether the dimensioning from point A to point B is redundant is: whether there is a unique annotation path from point A to point B. If so, it means that the dimensioning is complete; if missing, it means that the dimensioning is missing; if there are multiple paths, it means that the dimensioning is redundant.

[0020] A three-dimensional part dimension automatic marking system is also provided, including a marking plane and marking view creation module, a marking reference coordinate system creation module, a model dimension automatic marking module, a full selection marking dimension module, a full selection circular hole dimension module, a same circular hole dimension merging module, an automatic tolerance module, a dimension spacing adjustment module, and a technical requirement creation module; the above modules and the steps of the above methods are used to automatically mark the three-dimensional part dimensions.

[0021] Furthermore, the system uses a mouse and keyboard as input; the system cooperates with an external database system to realize the storage and reading of annotation process data; the system is integrated and secondary developed based on the 3D CAD design software API interface and is integrated in the 3D CAD design software menu bar.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The method provided by the present invention does not rely on machine learning algorithms, has good practicality and versatility, is simple to develop algorithms, and is easy to integrate into three-dimensional CAD design software. It can ensure the rationality, completeness, and clarity of the annotation results to a certain extent.

[0024] (2) The present invention can help designers quickly implement three-dimensional part dimensioning and improve design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of realizing automatic labeling according to an embodiment of the present invention.

[0026] Figure 2 Schematic diagram of the system architecture of an embodiment of the present invention.

[0027] Figure 3 It is a main view of a three-dimensional part automatic annotation result diagram before redundant inspection according to an embodiment of the present invention.

[0028] Figure 4 It is a side view of an automatic annotation result diagram of a three-dimensional part before redundant inspection according to an embodiment of the present invention.

[0029] Figure 5 It is the main view of the automatic marking result diagram of a three-dimensional part after deleting redundant dimensions in an embodiment of the present invention.

[0030] Figure 6 It is a side view of the automatic labeling result diagram of a three-dimensional part after deleting redundant dimensions in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0032] This embodiment provides a method and system for automatic dimensioning of three-dimensional parts to realize automatic dimensioning of three-dimensional parts.

[0033] like Figure 1 As shown, the specific steps of realizing automatic dimensioning of three-dimensional parts using the method of the present invention are as follows:

[0034] 1) Create annotation views and annotation planes. Designers manually create annotation views and annotation planes, and the annotation views correspond to the annotation planes.

[0035] 2) Create a reference coordinate system for annotation. Based on each annotation plane, the designer manually selects the annotation reference point and creates a reference coordinate system, with the horizontal direction as the X-axis and the vertical direction as the Y-axis. All subsequent dimensioning is based on the reference coordinate system.

[0036] 3) Model simplification: Based on the 3D model of the part, reversely traverse the model features, put the fillet and chamfer features into the stack, and delete the fillet and chamfer features to make the model more concise.

[0037] 4) Calculation of model feature boundary coordinates. Model feature boundaries are straight edges or arc edges. In the annotation view direction, the intersection of the straight edge and other edges automatically identifies the point coordinates (X1, Y1), (X2, Y2)... and converts them into the point coordinates (X1, Y1), (X2, Y2)... in the annotation reference coordinate system. 0 1. Y 0 1) (X 0 2. Y 0 2)…; For arc edges, automatically identify and convert the center position coordinates.

[0038] 5) Project and mark the model feature boundary coordinates. Project the model feature boundary coordinates onto the X-axis and Y-axis of the marking reference coordinate system, merge the same coordinates, and mark the model dimensions in the X-axis and Y-axis directions.

[0039] 6) Arc edge feature size processing. Automatically mark the arc radius size at the arc edge position.

[0040] 7) Model feature restoration. Pop the model fillet and chamfer features that are put into the stack, restore the model fillet and chamfer features one by one, and mark the fillet and chamfer positions and sizes in the form of technical requirements text + color marking.

[0041] 8) Check the redundancy of annotation results. According to the steps, the automatic dimensioning results in each annotation view must be clear and complete. However, the annotation results of the same feature in different annotation views (common views include left and right, pitch, and front and rear views) may be redundant. The "annotation point path method" is used to check the redundancy of the automatic dimensioning results in multiple annotation views and mark the redundant dimensions.

[0042] 9) The designer confirms the marking results. If there are redundant marking dimensions, the designer can delete the redundant dimensions according to the prompts.

[0043] The annotation point path method described in step 8 is as follows: There are two points in space (point A and point B). If there is a dimension annotation from point A to point B, then point A can follow the dimension annotation path to point B. If there are multiple dimension annotations between point A and point B, then there are multiple paths from point A to point B. The criterion for judging whether the dimension annotation from point A to point B is redundant is: whether there is a unique annotation path from point A to point B. If so, it means that the dimension annotation is complete; if it is missing, it means that the dimension annotation is missing; if there are multiple paths, it means that the dimension annotation is redundant. See for details. Figure 3 , Figure 5 , Figure 4 and Figure 6 . Figure 3 and Figure 4 This is the result of automatic dimensioning of a 3D part before redundancy check. Figure 5 and Figure 6 This is the annotation result after deleting redundant dimensions. Figure 3 The technical requirements are: 1. Fillet: size: R2, location: the two rectangular areas on the upper and lower right sides of the figure; 2. Chamfer: size: C0.5, location: the isosceles trapezoidal area on the far left of the figure; 3. Plating: Fe / CtP; 4. Coating: None. Figure 5 The technical requirements are: 1. Fillet: size: R2, location: the two rectangular areas on the right side of the figure; 2. Chamfer: size: C0.5, location: the isosceles trapezoidal area on the far left of the figure; 3. Plating: Fe / CtP; 4. Coating: None. It can be found that the dimensioning between points A and B is redundant, and there are two dimensioning paths from point A to point B; the dimensioning between points C and D is reasonable, clear and complete, and there is only one dimensioning path from point C to point D.

[0044] like Figure 2 As shown, another aspect of the present invention provides a 3D part dimension automatic marking system, which realizes the development of the automatic marking method; the system is based on the VS2008 platform, uses C++ language and SQL Server database, and uses Pro / Toolkit provided by Creo for secondary development. See the system architecture Figure 2 . The system provides a software interactive interface; the system provides the function of creating annotation planes and annotation views, the function of creating annotation reference coordinate systems, and the function of automatically annotating model dimensions. The system also provides other functions, including: a function of selecting all annotation dimensions, a function of selecting all circular hole dimensions, a function of merging the same circular hole dimensions, an automatic tolerance function, a dimension spacing adjustment function, and a technical requirements creation function. Designers can select all annotation dimensions to adjust tolerances and dimension spacing. Designers can choose to merge and annotate the same circular hole dimensions. Secondly, the system uses the mouse and keyboard as input to interact with designers; the system cooperates with an external database system to store and read annotation process data; the system is integrated and secondary developed based on the 3D CAD design software API interface and is integrated into the 3D CAD design software menu bar.

[0045] The process of realizing automatic dimensioning of three-dimensional parts using the system is as follows:

[0046] 1) System startup: After the 3D part design is completed, click on the menu bar of the 3D CAD design software to start the system;

[0047] 2) Annotation view creation: Create the required annotation view in the 3D CAD design software, and the system automatically recognizes and records it; click the "Create Annotation View" button to create the required annotation view in the Creo model interface, and the system automatically recognizes and records it;

[0048] 3) Annotation plane creation: Create the required annotation plane in the 3D CAD design software, and the system automatically recognizes and records it; click the "Create Annotation Plane" button to create the required annotation plane in the Creo model interface, and the system automatically recognizes and records it;

[0049] 4) Creation of annotation reference coordinate system: In each annotation plane, select the annotation reference point to create the annotation reference coordinate system, which the system automatically recognizes and records; click the "Create annotation reference coordinate system" button, and in the Creo model interface, select the annotation reference point in each annotation plane to create the annotation reference coordinate system, which the system automatically recognizes and records;

[0050] 5) Automatic labeling: Click the automatic labeling button, and the system will automatically label the dimensions of the three-dimensional model using the automatic labeling method.

[0051] 6) Dimensioning result check: Designers check the automatic dimensioning results and delete redundant dimensions.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1) The present invention helps designers quickly realize three-dimensional part dimensioning, and the marking efficiency is improved by 80%;

[0054] 2) The algorithm of the present invention is easy to develop and can be integrated and developed based on the API interface of the 3D CAD design software, making it easy to implement;

[0055] 3) The present invention does not rely on artificial intelligence algorithms or large amounts of data samples, and is highly practical and versatile;

[0056] 4) An example of automatic annotation of the present invention is Figure 4 ,The automatic annotation results of the present invention are reasonable, clear and complete.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for automatically marking the dimensions of a three-dimensional part, characterized in that: The following steps are involved: 1) Create annotation views and annotation planes; 2) Create a reference coordinate system for annotation; 3) Model simplification; 4) Calculation of model feature boundary coordinates; 5) Project and mark the model feature boundary coordinates; 6) Arc edge feature size processing: mark the arc radius size at the arc edge position; 7) Model feature restoration.

2. The method for automatic dimensioning of three-dimensional parts according to claim 1, characterized in that: After the model feature restoration, the annotation result redundancy check and annotation result confirmation are also performed.

3. The method for automatic dimensioning of three-dimensional parts according to claim 1, characterized in that: The creation of the annotation reference coordinate system is specifically as follows: based on each annotation plane, an annotation reference point is selected and a reference coordinate system is created, with the horizontal direction being the X-axis and the vertical direction being the Y-axis, and all subsequent dimension annotations are performed based on the reference coordinate system.

4. The method for automatic dimensioning of three-dimensional parts according to claim 1, characterized in that: The model feature boundary coordinate calculation specifically includes: according to the three-dimensional model of the part, reversely traversing the model features, placing the fillet and chamfer features into the stack, and deleting the fillet and chamfer features.

5. The method for automatic dimensioning of three-dimensional parts according to claim 1, characterized in that: The calculation of model feature boundary coordinates specifically includes: the model feature boundary is a straight edge or an arc edge. In the annotation view direction, the intersection of the straight edge and other edges is identified, and the point coordinates (X1, Y1), (X2, Y2)... are converted into the point coordinates (X1, Y1), (X2, Y2)... in the annotation reference coordinate system. 0 1. Y 0 1) (X 0 2. Y 0 2)…; For the arc edge, identify and convert the center position coordinates.

6. The method for automatic dimensioning of three-dimensional parts according to claim 3, characterized in that: The model feature boundary coordinate projection and annotation specifically includes the following steps: projecting the model feature boundary coordinates onto the X-axis and Y-axis of the annotation reference coordinate system, merging the same coordinates, and annotating the model dimensions in the X-axis and Y-axis directions.

7. The method for automatic dimensioning of three-dimensional parts according to claim 4, characterized in that: The model feature restoration specifically includes: popping the model fillet and chamfer features put into the stack, restoring the model fillet and chamfer features one by one, and marking the fillet and chamfer positions and sizes in the form of technical requirement text + color marking.

8. The method for automatic dimensioning of three-dimensional parts according to claim 2, characterized in that: The dimensioning results in multiple annotation views are checked for redundancy according to the annotation point path method, and the redundant annotation dimensions are marked. The annotation point path method specifically includes the following steps: two points in space are point A and point B. If there is a dimension from point A to point B, then it is possible to reach point B from point A along the dimension path; if there are multiple dimension annotations between point A and point B, then there are multiple paths from point A to point B; the criterion for judging whether the dimension from point A to point B is redundant is: whether there is a unique annotation path from point A to point B. If so, it means that the dimension is complete; if not, it means that the dimension is missing; if there are multiple paths, it means that the dimension is redundant.

9. A three-dimensional part dimension automatic marking system, characterized in that: It includes a module for creating annotation planes and annotation views, a module for creating an annotation reference coordinate system, a module for automatically annotating model dimensions, a module for selecting all annotation dimensions, a module for selecting all circular hole dimensions, a module for merging dimensions of identical circular holes, an automatic tolerance module, a module for adjusting dimension spacing, and a module for creating technical requirements; the above modules automatically annotate three-dimensional part dimensions according to the steps of the method described in any one of claims 1 to 8.

10. A three-dimensional part dimension automatic marking system as claimed in claim 9, characterized in that: The system uses the mouse and keyboard as input; the system cooperates with an external database system to realize the storage and reading of the annotation process data; the system is integrated and secondary developed based on the 3D CAD design software API interface and is integrated in the 3D CAD design software menu bar.

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