A machining sequence and step generation method based on a three-dimensional CAD model
By using image recognition technology based on 3D CAD models, machining processes and steps are automatically generated, solving the problem of low efficiency in manually determining process data in existing technologies and realizing efficient machining process design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CAPITAL AEROSPACE MACHINERY
- Filing Date
- 2023-10-18
- Publication Date
- 2026-06-23
AI Technical Summary
Currently, the machining process design of 3D models relies on manual determination of process data, resulting in low automation levels and inefficiency.
By using image recognition technology based on 3D CAD models, the contour lines and internal lines are automatically extracted, and machining processes and steps are automatically generated, reducing manual intervention.
It has automated the design of machining processes, improved work efficiency and quality, and reduced the amount of manual labor.
Smart Images
Figure CN117348523B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of digital manufacturing, and in particular to a method for generating machining processes and steps based on a three-dimensional CAD model. Background Technology
[0002] Currently, the process data for various 3D models are mainly determined manually, and the level of automation is not high. Summary of the Invention
[0003] This application provides a novel method for generating machining processes and steps based on a 3D CAD model. By extracting information from the current 3D CAD model, using image recognition of the model view, and applying appropriate generation methods, the method achieves automatic generation of machining process steps and nodes, reducing manual work and assisting in the design of machining processes based on 3D CAD models.
[0004] Firstly, a method for generating machining processes and steps based on a 3D CAD model is provided, including:
[0005] Obtain the target view of the 3D CAD model;
[0006] The target view is identified to obtain the outline and internal wireframe of the target view.
[0007] The process sequence and machining steps for this part are determined based on the internal wireframe and the outline wireframe.
[0008] In conjunction with the first aspect, in some implementations of the first aspect, obtaining the target view of the 3D CAD model includes obtaining multiple directional views of the 3D CAD model; determining the process sequence of the part satisfies:
[0009] If the following conditions are met: the outer contour of the target view is a circle or a regular polygon, then the orientation of the target view is taken as the first processing order;
[0010] If the following conditions are not met: the outer contour of the target view is a circle or a regular polygon, but the following conditions are met: both directions of the target view have internal closed wireframes, and the direction of the target view is used as the first processing order.
[0011] In conjunction with the first aspect, in some implementations of the first aspect, if multiple directional views do not satisfy the condition that the outer contour of the target view is a circle or a regular polygon, but satisfy the condition that each pair of directions of the target view has an internal closed wireframe, then the direction with more internal wireframes is taken as the first processing order.
[0012] In conjunction with the first aspect, in some implementations of the first aspect, the processing sequence is determined according to the area of the circumcircle of the view from smallest to largest.
[0013] In conjunction with the first aspect, in certain implementations of the first aspect, determining the processing steps of the part includes:
[0014] Identify the internal wireframe of the target view. If a circular wireframe outline exists, the target view has a turning operation. If a polygonal outline exists, the target view has a milling operation. If both exist, the target view has both turning and milling operations.
[0015] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: determining the processing steps of the processing operation, including:
[0016] Iterate through the model view corresponding to each process in the process dataset;
[0017] Identify and generate a dataset of the internal closed contours of each model view;
[0018] Traverse and identify the internal closed contour dataset from the outside to the inside, identify whether the contour lines of each closed contour exist at the corresponding positions in other directional views in the directional dataset, generate the construction steps in sequence from the outside to the inside, and give the construction step dataset.
[0019] In conjunction with the first aspect, in some implementations of the first aspect, if the contour line at the corresponding position exists, the step-filling step dataset is generated according to the following steps:
[0020] When the closed contour in the internal closed contour dataset is a circle and is on the outermost side, generate the outer circle machining step in the machining step dataset.
[0021] When the closed contour in the internal closed contour dataset is a circle but not the outermost one, generate the vehicle shape steps in the step dataset.
[0022] When the closed contour in the internal closed contour dataset is not a circle, the milling outline step in the step dataset is generated.
[0023] In conjunction with the first aspect, in some implementations of the first aspect, if the contour line at the corresponding position does not exist, the step-filling step dataset is generated according to the following steps:
[0024] When the closed contour in the internal closed contour dataset is a circle and is on the outermost side, generate the outer circle machining step in the machining step dataset.
[0025] When the closed contour in the internal closed contour dataset is a circle but not the outermost one, generate the drilling step in the step dataset.
[0026] When the closed contour in the internal closed contour dataset is not a circle, generate the milling internal shape step in the step dataset.
[0027] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes:
[0028] Extract text annotations from the 3D CAD model to determine auxiliary processes for the 3D CAD model:
[0029] If a heat treatment identifier is present in the model text annotation, then a heat treatment process has been performed.
[0030] If a surface treatment identifier is present in the model text annotation, then a surface treatment process has been performed.
[0031] In conjunction with the first aspect, in some implementations of the first aspect, obtaining the target view of the 3D CAD model includes:
[0032] Convert the 3D CAD model of the part into an unannotated lightweight model, and obtain the target view based on the unannotated lightweight model.
[0033] Compared with the prior art, the solution provided in this application has at least the following beneficial technical effects:
[0034] (1) By extracting information from the three-dimensional CAD model, process data of machined parts are automatically generated based on the rule model.
[0035] (2) By extracting information from the three-dimensional CAD model, the machining step data of the machined parts is automatically generated based on the rule model.
[0036] (3) Based on the three-dimensional CAD model, the process step data can be automatically generated, which can be effectively applied to the rapid process design and process specification preparation based on the three-dimensional CAD model, reducing manual work and significantly improving work efficiency and quality. Attached Figure Description
[0037] Figure 1 This is a schematic diagram of a method for generating machining processes and steps based on a 3D CAD model.
[0038] Figure 2 This is a schematic diagram of a method for obtaining a target view of a 3D CAD model.
[0039] Figure 3 This is a schematic diagram illustrating how to determine the machining sequence of a part.
[0040] Figure 4 This is a schematic diagram illustrating a specific machining process for a part.
[0041] Figure 5 This is a schematic diagram illustrating a specific machining step for a part.
[0042] Figure 6 This is a schematic diagram of an auxiliary process for determining a part. Detailed Implementation
[0043] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0044] With the development and deepening of 3D product development, more and more mechanical products are adopting 3D design and manufacturing technologies. In the process design stage of mechanical structural components, a certain technical and data foundation has been established for information extraction and data reuse from 3D CAD models. This allows for the reduction of manual operations and the improvement of work efficiency and quality through methods such as generating process data based on 3D CAD models. In the process design of machined products based on 3D CAD models, after accumulating sufficient data on process schemes consisting of operations and steps, it is possible to establish corresponding data models and software tools, combined with information extraction from the 3D CAD models of parts, to automatically generate machining operations and steps based on the 3D CAD models of parts.
[0045] See Figure 1 This application provides a method for generating machining processes and steps based on a three-dimensional CAD model.
[0046] Step 1: Obtain the target view of the 3D CAD model. The target view can be one or more of the top, bottom, left, right, front, and rear views.
[0047] In some embodiments, a machining process step generation software tool can be established to load and open the 3D CAD model. It automatically captures model views in six directions: top, bottom, left, right, front, and back. In one possible scenario, the 3D CAD model can be preprocessed before view capture, converting the opened part 3D CAD model into a lightweight, unannotated model, i.e., removing the annotation data of the 3D CAD model and retaining only its structural features.
[0048] Step 2: Identify the target view, obtain the outline and internal wireframes, and determine the process sequence and machining steps for the part. The internal wireframes can be obtained by hiding the outline of the 3D CAD model.
[0049] In some embodiments, the model views are traversed, and an image recognition module is used to perform image recognition on the model views. The main machining direction (first machining sequence) of the part is determined through image recognition. After the main machining direction is determined, other machining directions of the part are identified and determined. When identifying machining directions, for each view, the image recognition and processing module is used to separate the outline frame and the internal frame of the view to form two images.
[0050] In some embodiments, image recognition is performed on the internal wireframe image, and when the internal wireframe image contains a closed polygon or circle, that direction is the direction that needs to be processed.
[0051] In some embodiments, the internal wireframes of each machining direction are identified. When a circular wireframe outline exists, a turning operation is performed in that direction; when a polygonal outline exists, a milling operation is performed in that direction. If both conditions exist, then both turning and milling operations are performed in that direction.
[0052] In some embodiments, the internal wireframe of the identification view is found to have an arc segment of a certain length (a set length threshold). If an arc segment exists, a milling operation is performed in its vertical direction.
[0053] In some embodiments, step 3 is further included: extracting text annotations from the 3D CAD model to determine auxiliary processes for the 3D CAD model.
[0054] For example, if a heat treatment identifier is present in the model text annotation, then a heat treatment process exists; similarly, if a surface treatment identifier is present in the model text annotation, then a surface treatment process exists.
[0055] Example 1
[0056] This method combines process and step generation rules to automatically generate process and step data based on the 3D CAD model of the machined part by extracting text annotations and geometric shape data from the 3D CAD model. The specific implementation steps are as follows.
[0057] Step 1: Obtain the target view of the 3D CAD model. (Reference) Figure 2 The specific implementation is as follows.
[0058] (1.1) Establish and apply machining process step generation tools.
[0059] (1.2) Open the three-dimensional CAD model of the part using software tools (a.1).
[0060] (1.3) Based on software tools, the opened 3D CAD model of the part (a.1) is converted into an unannotated lightweight model (a.2).
[0061] (1.4) Based on software tools, automatically extract model views from six directions of the lightweight model (a.2) to form a model view dataset (a.3).
[0062] (1.5) Group the model view dataset (a.3) according to the top (A) bottom (B), left (C) right (D), front (E) back (F) views to form AB, CD, EF direction datasets (a.4).
[0063] Step 2: Determine the machining sequence of the part based on its external contour. (Reference) Figure 3 The specific implementation is as follows.
[0064] (2.1) Image recognition is performed based on the orientation dataset (a.4). When the outer contour of the orientation view is a circle or a regular polygon, it is used as the first processing order in the orientation dataset (a.4).
[0065] (2.2) For cases that do not belong to (2.1), select the direction in the direction dataset (a.4) where both pairs of directions have internal closed wireframes. This direction is used as the first processing order in the direction dataset (a.4).
[0066] (2.3) When the first processing order in the direction dataset (a.4) is not unique according to the recognition methods of (2.1) and (2.2), the direction with the most internal wireframes in the direction dataset (a.4) shall be the first processing order.
[0067] (2.4) When the first processing order in the direction dataset (a.4) according to (2.3) is not unique, the direction with the larger outer contour size in the direction dataset (a.4) shall be the first processing order.
[0068] (2.5) In the orientation dataset (a.4), identify the area of the circumcircle of the paired views and prioritize the view with the smaller area as the orientation view.
[0069] Step 3: Identify the target view, obtain the internal wireframe within the target view, and determine the machining process for the part based on the internal wireframe. (Reference) Figure 4 The specific implementation is as follows.
[0070] (3.1) Traverse the views in 6 directions (a.3), perform image recognition in sequence, identify the outer contour wireframe and inner wireframe of each view (a.3.n), separate the wireframes, and form a wireframe dataset (b.1).
[0071] (3.2) Identify whether there are closed shapes in the internal wireframe dataset (b.1) to form a closed wireframe dataset (b.2) and a process dataset to be filled (b.3).
[0072] (3.3) If there are one or more closed circular wireframes in the closed wireframe dataset (b.2), add a machining operation in the view direction to fill the operation dataset (b.3).
[0073] (3.4) Identify whether there are one or more non-central holes in the internal wireframe of the closed wireframe dataset (b.2). If so, add a milling operation in the view direction to fill the operation dataset (b.3).
[0074] (3.5) If there are one or more closed polygonal wireframes in the closed wireframe dataset (b.2), add a milling operation in the view direction to fill the operation dataset (b.3).
[0075] (3.6) Identify whether there are arcs in the outer wireframe of the wireframe dataset (b.1). If so, add a milling operation in its vertical view direction to fill the operation dataset (b.3).
[0076] Step 4: Based on the part's machining process, determine the machining steps for each machining process. (Reference) Figure 5 The specific implementation is as follows.
[0077] (4.1) Traverse the model view (a.3) corresponding to each process in the process dataset (b.3).
[0078] (4.2) Identify and generate the internal closed contour dataset (e.1) for each model view (a.3).
[0079] (4.3) Traverse and identify the internal closed contour dataset (e.1) from the outside to the inside. First, identify whether the contour lines of each closed contour exist in the corresponding positions of other directional views in the directional dataset (a.4). Then, generate the work steps in sequence from the outside to the inside and give the work step dataset (e.2).
[0080] (4.4a) If the contour line at the corresponding position in (4.3) exists, then generate the step filling step dataset (e.2) according to the following steps:
[0081] • When the closed contour in the internal closed contour dataset (e.1) is a circle and is on the outermost side, generate the external circle work steps in the work step dataset (e.2).
[0082] • When the closed contour in the internal closed contour dataset (e.1) is a circle but not the outermost one, generate the vehicle shape steps in the step dataset (e.2).
[0083] • When the closed contour in the internal closed contour dataset (e.1) is not circular, generate the milling outline step in the step dataset (e.2).
[0084] (4.4b) If the contour line at the corresponding position in (4.3) does not exist, then generate the step filling step dataset (e.2) according to the following steps:
[0085] • When the closed contour in the internal closed contour dataset (e.1) is a circle and is on the outermost side, generate the external circle work steps in the work step dataset (e.2).
[0086] • When the closed contour in the internal closed contour dataset (e.1) is a circle but not the outermost one, generate the drilling steps in the step dataset (e.2).
[0087] • When the closed contour in the internal closed contour dataset (e.1) is not circular, generate the milling internal shape step in the step dataset (e.2).
[0088] Step 5: Extract the text annotations from the 3D CAD model to determine the auxiliary processes required for the 3D CAD model. (Refer to...) Figure 6 The specific implementation is as follows.
[0089] (5.1) Identify the three-dimensional CAD model (a.1) Text annotation content (d.1).
[0090] (5.2) Identify heat treatment and surface treatment markings (d.2) in the text annotations (d.1).
[0091] (5.3) Based on the heat treatment and surface treatment identifiers (d.2), provide the heat treatment and surface treatment process dataset (d.3).
[0092] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.
Claims
1. A method for generating machining processes and steps based on a 3D CAD model, characterized in that, include: Obtain the target view of the 3D CAD model; The target view is identified to obtain the outline and internal wireframe of the target view. The machining process and steps of the part are determined based on the internal wireframe and the outline wireframe. The process of obtaining the target view of the 3D CAD model includes obtaining multiple directional views of the 3D CAD model; the process sequence of determining the part satisfies the following: If the following conditions are met: the outer contour of the target view is a circle or a regular polygon, then the orientation of the target view is taken as the first processing order; If the following conditions are not met: the outer contour of the target view is a circle or a regular polygon, but the following conditions are met: both directions of the target view have internal closed wireframes, and the direction of the target view is used as the first processing order; If multiple directional views do not satisfy the condition that the outer contour of the target view is a circle or a regular polygon, but satisfy the condition that each pair of directions of the target view has an internal closed wireframe, then the direction with more internal wireframes will be the first processing order. The method further includes: determining the processing steps of the processing procedure, including: Iterate through the model view corresponding to each process in the process dataset; Identify and generate a dataset of the internal closed contours of each model view; Traverse and identify the internal closed contour dataset from the outside to the inside, identify whether the contour lines of each closed contour exist at the corresponding positions in other directional views in the directional dataset, generate the construction steps in sequence from the outside to the inside, and give the construction step dataset.
2. The method according to claim 1, characterized in that, The processing sequence is determined by increasing the area of the circumcircle of the view.
3. The method according to claim 1, characterized in that, The process of determining the machining steps of the part includes: Identify the internal wireframe of the target view. If a circular wireframe outline exists, the target view has a turning operation. If a polygonal outline exists, the target view has a milling operation. If both exist, the target view has both turning and milling operations.
4. The method according to claim 1, characterized in that, If the outline exists at the corresponding location, generate the step-filling step dataset according to the following steps: When the closed contour in the internal closed contour dataset is a circle and is on the outermost side, generate the outer circle machining step in the machining step dataset. When the closed contour in the internal closed contour dataset is a circle but not the outermost one, generate the vehicle shape steps in the step dataset. When the closed contour in the internal closed contour dataset is not a circle, the milling outline step in the step dataset is generated.
5. The method according to claim 1, characterized in that, If the outline at the corresponding position does not exist, generate the step-filling step dataset according to the following steps: When the closed contour in the internal closed contour dataset is a circle and is on the outermost side, generate the outer circle machining step in the machining step dataset. When the closed contour in the internal closed contour dataset is a circle but not the outermost one, generate the drilling step in the step dataset. When the closed contour in the internal closed contour dataset is not a circle, generate the milling internal shape step in the step dataset.
6. The method according to claim 1, characterized in that, The method further includes: Extract text annotations from the 3D CAD model to determine auxiliary processes for the 3D CAD model: If a heat treatment identifier is present in the model text annotation, then a heat treatment process has been performed. If a surface treatment identifier is present in the model text annotation, then a surface treatment process has been performed.
7. The method according to claim 1, characterized in that, The process of obtaining the target view of the 3D CAD model includes: Convert the 3D CAD model of the part into an unannotated lightweight model, and obtain the target view based on the unannotated lightweight model.