Batch modification method and system for arc-shaped parts

Abstract

The invention relates to the technical field of computer aided design and manufacturing, and provides a batch modification method and system.The method includes the steps that all parts of a current model are traversed, and according to parameter information of all the parts, the parts with the section types being circular rings and meeting preset parameter requirements are screened as a first part set; further identifying the arc-shaped parts of which the center lines are fixed in curvature in the first part set; and geometric relationship judgment is conducted on all the arc-shaped parts, and all the screened arc-shaped parts are modified into linear parts by moving part control points. According to the full-automatic batch processing method, the arc-shaped parts are automatically recognized and screened according to the machining requirements, and the arc-shaped parts are modified into the linear parts, and the problems that in an existing scheme, arc-shaped part through opening machining depends on manpower, and the batch processing efficiency is low during part modification are solved.

Description

Technical Field

[0001] The present application relates to the field of computer-aided design and manufacturing technology, and in particular to a method and system for batch modification of arc-shaped parts. Background Art

[0002] Round pipes are extensively used in the manufacturing and cutting of steel handrails, guardrail systems, and other similar spatial grid structures. These pipes are often connected by intersecting welds to ensure structural stability and aesthetics. In such projects, some pipes are designed as curved parts for aesthetic or functional reasons. However, the following problems are common during the production, processing, and joint processing of these curved parts: 1. The intersection of curved parts has a complex spatial surface. In many cases, standard CNC cutting equipment cannot be used for programming and cutting. Manual cutting is often required by skilled workers. Operators need to rely on their personal experience to lay out and draw lines on the actual pipe, and then use handheld plasma or flame cutting machines for processing. This results in low efficiency and quality of the intersection processing. 2. When using CNC equipment for automated cutting, designers must first modify curved parts into straight lines within the 3D model without compromising production requirements. Existing general-purpose 3D software lacks batch processing tools for this specific requirement. The current workflow requires designers to manually manipulate each curved part: first, they draw a straight line between the part's endpoints, then manually select and drag the arc's middle control point to align it with the line, thereby "straightening" the part.

[0003] Therefore, the existing technology has major technical bottlenecks in the above two aspects, which makes the actual design and manufacturing process inefficient and the labor cost high, thus affecting the production quality. Summary of the Invention

[0004] The purpose of this application is to provide a method and system for batch modification of arc-shaped parts to solve the problems described in the background technology section of this application.

[0005] To achieve the above-mentioned purpose, the first aspect of this application provides the following technical solutions: In a first aspect, the present application provides a method for batch modification of arc-shaped parts, the method comprising: Traversing all parts of the current model, and based on parameter information of each part, selecting parts whose cross-section type is a ring and that meet preset parameter requirements as a first part set, wherein the parameter types in the preset parameter requirements include cross-section outer diameter and wall thickness; Traversing each part in the first part set, identifying arc-shaped parts in the first part set, and filtering each of the arc-shaped parts into a second part set, wherein the center lines of the arc-shaped parts are circular arc curves with a constant curvature; Performing geometric relationship judgment on each of the arc-shaped parts in the second part set, and modifying the arc-shaped parts into straight-shaped parts according to the geometric relationship judgment results, wherein the center line of the straight-shaped parts is a straight line, wherein: If at least one end of the arc-shaped part is connected to a first part, and the connection type is a through-connection and the cutting surface of the arc-shaped part is a cylindrical surface, the arc-shaped part is modified into a straight part after the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the center line of the first part; If at least one end of the arc-shaped part is connected to a second part, when the connection type is a flat connection and the cutting surface of the arc-shaped part is a plane, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the plane cutting surface, and the arc-shaped part is modified into a straight part.

[0006] Furthermore, when it is impossible to obtain the cross-section type and determine the preset parameter requirements based on the parameter information of each part, the method further includes: Cutting the part at equal intervals along the length of the part using a preset plane to obtain a plurality of cross-sectional contour lines, wherein the preset plane is perpendicular to the tangent direction of the center line of the part at the cutting point; One or more fitting circles are formed based on the point set of the cross-sectional contour line, and the distance from each point on the outer cross-sectional contour line to the center of the corresponding fitting circle is obtained. If the difference between the distance from all points on the outer cross-sectional contour line to the center of the corresponding fitting circle and the radius of the fitting circle is within a preset range, and the radius of the fitting circle corresponding to the outer cross-sectional contour line of each cutting point is equal, then the interface type of the part is a circular cross-section; If the number of fitting circles formed by the cross-sectional contour line of a single cutting point is 2, the cross-sectional type of the part is a circular cross-section; The cross-sectional outer diameter and wall thickness of the part are obtained according to the cross-sectional contour line, and parts whose cross-sectional type is annular and meets the preset parameter requirements are screened as the first part set.

[0007] Furthermore, traversing the parts in the first part set and identifying arc-shaped parts in the first part set includes: Obtaining a radius attribute value of each part in the first part set, wherein the radius attribute value is used to represent a radius value of an arc where a center line of the part is located; If the radius attribute value is not 0, the part is determined to be an arc-shaped part; If the radius attribute value is 0, then read the number of control points of the part and determine whether each control point is located on the same straight line. If the number of control points of the part is greater than 2, then further obtain the curvature value of each control point on the curve formed by each control point, and determine whether each control point is located on the same straight line based on the curvature value. If the control points are not located on the same straight line and the curvature values ​​of the control points are equal, it is determined that the part is a curved part.

[0008] Furthermore, the determining whether the control points are located on the same straight line includes: Set a curvature threshold and obtain the relationship between the curvature value of each control point on the curve formed by the control points and the curvature threshold: If the curvature values ​​of the control points are all less than the curvature threshold, the part is judged to be a straight part; if the curvature values ​​of the control points are all greater than the curvature threshold, and the curvature values ​​of the control points are all equal, the part is judged to be an arc part.

[0009] Furthermore, the step of modifying the arc-shaped part into a straight-shaped part comprises: After moving the end control point of the arc part according to the connection type of the arc part, three control points of the arc part are respectively obtained, including a first end control point, a second end control point, and an intermediate control point, wherein the intermediate control point is a control point located between the first end control point and the second end control point, and the first end control point and / or the second end control point are the end control points of the connection end of the arc part; The first end control point and the second end control point are connected to form a first straight line, and the intermediate control point is moved to the first straight line to obtain the straight-line part. After modification, the length of the straight-line part is different from that of the arc-shaped part.

[0010] Furthermore, the method further comprises: If at least one end of the arc-shaped part is connected to a third part, and the connection type is free splicing without cutting of the end, respectively obtain the first end control point, the second end control point, and the middle control point of the arc-shaped part, where the middle control point is a control point located between the first end control point and the second end control point; The intermediate control point is moved to a straight line formed by the first end control point and the second end control point to obtain the straight-line part.

[0011] Furthermore, when the end control point of the arc-shaped part is moved, it is moved along the center line of the arc-shaped part.

[0012] Furthermore, after the arc-shaped parts in the first part set are identified, the arch height of each of the arc-shaped parts is obtained, and the arc-shaped parts that meet the preset arch height requirements are screened as the second part set.

[0013] Preferably, the method is implemented based on Grasshopper.

[0014] The second aspect of the present application provides a batch modification system for arc-shaped parts. The method described in the first aspect of the present application is implemented based on the system described in the second aspect of the present application, and the system includes: A ring part screening module is used to traverse all parts of the current model and, based on the parameter information of each part, screen the parts whose cross-section type is a ring and meets the preset parameter requirements as a first part set. The parameter types in the preset parameter requirements include the cross-section outer diameter and wall thickness; a curved part screening module, configured to traverse each part in the first part set, identify the curved parts in the first part set, and screen each of the curved parts into a second part set, wherein the center lines of the curved parts are circular arcs with a fixed curvature; A part type modification module is used to perform geometric relationship judgment on each of the arc-shaped parts in the second part set, and based on the geometric relationship judgment result, modify the arc-shaped part into a straight-shaped part, wherein the center line of the straight-shaped part is a straight line: If at least one end of the arc-shaped part is connected to the first part, when the connection type is a through-end connection and the cutting surface of the arc-shaped part is a cylindrical surface, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the center line of the first part, and the arc-shaped part is modified to a straight part; if at least one end of the arc-shaped part is connected to the second part, when the connection type is a flat-end connection and the cutting surface of the arc-shaped part is a plane, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the plane cutting surface, and the arc-shaped part is modified to a straight part.

[0015] The present application provides the above-mentioned batch modification method for arc-shaped parts, which can at least achieve the following technical effects: This application provides a fully automated batch processing method for automatically identifying and screening arc parts according to processing requirements and modifying arc parts into straight parts, which greatly improves the efficiency and accuracy of part processing; in addition, by analyzing the geometric relationship of parts, the actual engineering connection requirements (such as through-ends and flat ends) are fully considered. By adjusting the end control points first and then straightening the entire part, it is ensured that the modified parts fully meet the original connection relationship and the feasibility of the design is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 A schematic flow chart of a method for batch modification of arc-shaped parts provided in an embodiment of the present application; Figure 2 A schematic diagram of the connection relationship provided in the embodiment of the present application; Figure 3 A schematic diagram of the flat port connection relationship provided in an embodiment of the present application; Figure 4 A schematic diagram of the control points of the moving parts provided in the embodiment of the present application; Figure 5 A schematic diagram of the free splicing relationship provided in the embodiment of the present application; Figure 6 A schematic diagram of the Grasshopper operation interface for screening tubular parts provided in an embodiment of the present application; Figure 7 A schematic diagram of the Grasshopper operation interface for screening curved parts provided in an embodiment of the present application; Figure 8 A schematic diagram of another Grasshopper operation interface for screening curved parts provided in an embodiment of the present application; Figure 9 A schematic diagram of the Grasshopper operation interface for modifying an arc segment into a straight line segment provided in an embodiment of the present application; Figure 10 A schematic diagram of the system architecture for batch modification of arc-shaped parts provided in an embodiment of the present application.

[0018] Figure numerals: 200, a batch modification system for arc parts; 201, annular parts screening module; 202, arc parts screening module; 203, part type modification module. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions of this application in conjunction with the embodiments. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0020] The embodiment of the present application provides a batch modification method for arc parts, which automatically identifies and screens arc parts according to processing requirements and modifies arc parts into linear parts in a fully automated batch process, greatly improving the efficiency and accuracy of part processing. In this embodiment, the following method is preferably implemented based on Rhino software and Grasshopper, such as Figure 1 As shown, this embodiment provides a batch modification method for arc parts, which specifically includes the following steps: Step S100: traverse all parts of the current model and, based on parameter information of each part, select parts whose cross-section type is a ring and meets preset parameter requirements as a first part set, where the parameter types in the preset parameter requirements include cross-section outer diameter and wall thickness; Specifically, in this embodiment, the current model is an arbitrary three-dimensional model, which contains a structured parameter file corresponding to each part, including various part parameter information, such as label, material specification, grade, quantity, length, part weight, cross-sectional diameter, wall thickness, arch height, radius attributes, and other parameters. In step S100, the parameter information of all parts in the model file is first traversed, and the API of the model software (such as Rhino software) is called through Grasshopper to obtain the cross-sectional parameters of all parts, including cross-sectional type, cross-sectional outer diameter, and wall thickness. Parts that meet the production requirements are screened as the first part set according to the preset parameter requirements, where the preset parameter requirements are determined based on the production requirements and optionally include cross-sectional outer diameter, wall thickness, and part material. In step S100, first, parts of non-circular tube type are excluded by screening for circular cross-section types; for parts with circular cross-section types, parts with cross-section outer diameters much smaller or much larger (the precision can be freely set, such as 1mm, 0.1mm, or 0.01mm) than the target cross-section outer diameter are further excluded; finally, for parts with circular cross-sections and cross-section outer diameters that meet the target cross-section outer diameter, parts with wall thicknesses greater than or less than the target wall thickness (such as 3mm) are further excluded. The preset parameter requirements in this step are formulated according to specific production and processing requirements, and can be further screened according to different parameter types. For example, if the preset parameter requirements also include parts with a material requirement of Q235B, the material information of the parts is further called to compare and exclude the target material information, and the parts finally screened out are used as the first part set.

[0021] Furthermore, in step S100, when it is impossible to obtain the cross-section type and determine the preset parameter requirement based on the parameter information of each part, the method further includes: Step S110: cutting the part at equal intervals along the length extension direction of the part using a preset plane to obtain a plurality of cross-sectional contour lines, wherein the preset plane is perpendicular to the tangent direction of the center line of the part at the cutting point; Step S120: forming one or more fitting circles based on the point set of the cross-sectional contour line, obtaining the distance from each point on the outer cross-sectional contour line to the center of the corresponding fitting circle, and if the difference between the distance from all points on the outer cross-sectional contour line to the center of the corresponding fitting circle and the radius of the fitting circle is within a preset range, and the radius of the fitting circle corresponding to the outer cross-sectional contour line of each cutting point is equal, then the interface type of the part is a circular cross-section; Step S130: If the number of fitting circles formed by the cross-sectional contour line of a single cutting point is 2, the cross-sectional type of the part is an annular cross-section; Step S140 : obtaining the cross-sectional outer diameter and wall thickness of the part according to the cross-sectional contour line, and selecting parts whose cross-sectional type is annular and meets the preset parameter requirements as the first part set.

[0022] Specifically, when the parameter information of each part in the model file is insufficient or missing, the cross-sectional type of the part and the various parameters in the preset parameter requirements are obtained through the geometric relationship of the parts. In this embodiment, preferably, multiple cross-sections are sampled along the centerline direction of the part (length extension direction): a preset plane is used to cut the part along the tangent direction of the centerline of the part at each cutting point at a certain interval (for example, 5-10 cross-sections) from one end to the other end of the part, and multiple cross-sectional contour lines corresponding to each cutting point are obtained. The cross-sectional contour lines corresponding to each cutting point may include one or more. First, the outer cross-sectional contour lines of each cutting point are analyzed: The point set of the cross-section contour line is fitted into a circle using the least squares method, i.e., the fitted circle. The distance from each point on the cross-section contour line to the center of the fitted circle and the difference between the distance and the radius of the fitted circle are calculated. If the difference of all points is within the preset tolerance range, the cross section is considered to be a circular cross section. In addition, it is necessary to ensure that the cross-section contour line is a closed loop. Secondly, determine whether each cutting point is a circular cross-section based on the outer cross-sectional contour lines of multiple cutting points. If the cross-sectional types of each cutting point are all circular cross-sections and the radii of each fitting circle are consistent, the part is a cylindrical part. Finally, if the cross-sectional contour lines at each cutting point include both inner and outer contour lines, and can form two corresponding fitting circles, the part is a tubular part. The part's cross-sectional outer diameter and wall thickness are further determined based on the cross-sectional contour lines. Wall thickness = outer fitting circle radius – inner fitting circle radius. Parts with annular cross-sectional types that meet the preset parameter requirements are selected as the first part set. In step S100, the combination of part element parameters and the geometric judgment of the cut parts greatly improves the accuracy of the part's cross-sectional type and required parameters, and enhances the reliability of the overall process. The preset parameters lay a standardized data foundation for subsequent automated batch processing.

[0023] Step S200: traverse each part in the first part set, identify arc parts in the first part set, and select each of the arc parts into a second part set, wherein the center lines of the arc parts are circular arc curves with a fixed curvature; Furthermore, in step S200, traversing the parts in the first part set and identifying arc-shaped parts in the first part set includes: Step S210: Obtaining a radius attribute value of each part in the first part set, wherein the radius attribute value is used to represent a radius value of an arc where the center line of the part is located; Step S220: If the radius attribute value is not 0, it is determined that the part is an arc-shaped part; Step S230: If the radius attribute value is 0, then read the number of control points of the part and determine whether each control point is located on the same straight line; if the number of control points of the part is greater than 2, then further obtain the curvature value of each control point on the curve formed by each control point, and determine whether each control point is located on the same straight line based on the curvature value; Step S240: If the control points are not located on the same straight line and the curvature values ​​of the control points are equal, it is determined that the part is a curved part.

[0024] Specifically, the first part set is parts with annular cross-sections, and step S200 further determines whether the parts are arc-shaped parts, that is, the center line of the parts is an arc with a constant curvature.

[0025] First, read the radius attribute of the part and determine whether its value is 0. If the radius attribute value is 0, it means that the part is not constructed by the two-point + radius method and is a non-arc part. Further control point determination is required. If the radius attribute value is not 0, it means that the part is an arc part and is selected as the second part set. Secondly, for parts with a radius attribute value of 0, the number of control points of the part is read by analyzing the part's build history. If the number of control points is greater than 2, it is necessary to further determine whether the control points are on a straight line. If the number of control points is ≤ 2, the part is determined to be a straight line with a radius attribute of 0, which does not meet the screening criteria for arc parts. Finally, for parts with more than two control points, the method for determining whether the control points lie on a straight line includes: setting a curvature threshold and determining the relationship between the curvature value of each control point on the curve formed by the multiple control points and the curvature threshold; if the curvature value of each control point is less than the curvature threshold, the part is determined to be a straight part; if the curvature value of each control point is greater than the curvature threshold and the curvature values ​​of all control points are equal, the part is determined to be an arc; otherwise, the part is rejected. Building on step S100, step S200 precisely isolates arc-shaped parts with regular geometric definitions that are most suitable for automated "curved-to-straight" processing, avoiding the risks and errors that may arise from applying algorithms to complex free-form curves, ensuring the reliability of the modification process and the accuracy of the results. Because the target is limited to a standard arc, its geometric properties (such as center, radius, and arc length) can be precisely calculated, providing a clear mathematical basis for subsequent operations such as determining geometric relationships and moving control points.

[0026] Step S300: Perform geometric relationship judgment on each of the arc-shaped parts in the second part set, and modify the arc-shaped parts into straight-shaped parts according to the geometric relationship judgment results, wherein the center line of the straight-shaped parts is a straight line, wherein: If at least one end of the arc-shaped part is connected to a first part, when the connection type is a through-end connection and the cutting surface of the arc-shaped part is a cylindrical surface, the end control point of the arc-shaped part connection end is moved to the intersection of the center line of the arc-shaped part and the center line of the first part, and the arc-shaped part is modified to a straight part; if at least one end of the arc-shaped part is connected to a second part, when the connection type is a flat-end connection and the cutting surface of the arc-shaped part is a plane, the end control point of the arc-shaped part connection end is moved to the intersection of the center line of the arc-shaped part and the plane cutting surface, and the arc-shaped part is modified to a straight part; If at least one end of the arc-shaped part is connected to a third part, and the connection type is free splicing and the end is not cut, the first end control point, the second end control point and the intermediate control point of the arc-shaped part are obtained respectively, and the intermediate control point is a control point located in the middle position between the first end control point and the second end control point; the intermediate control point is moved to the straight line formed by the first end control point and the second end control point to obtain the straight-line part.

[0027] Specifically, step S300 is used to analyze the geometric / intersection relationship of the parts, thereby further accurately screening the parts that need to be modified. For each arc-shaped part, determine its end connection relationship (through-end connection / flat-end connection, where Figure 2 As shown in , the cutting surface of the through-mouth connection is a cylinder; Figure 3As shown, the cutting surface of the flat-end connection is a plane), and accordingly, the end control point is first adjusted, and then the whole part is modified to a straight line. For through-end parts, by first moving the end control point to the intersection of the center lines of the two parts and then straightening them, it is ensured that the end of the modified straight-line part is still accurately located at the connection position of the original design, and the intersecting relationship with the other part (the first part) is maintained, providing an absolutely reliable geometric reference for the subsequent generation of the correct CNC intersecting line cutting path. For flat-end parts, first move the control point to the intersection of the center line and the cutting surface and then straighten it, ensuring that the end of the modified part still fits perfectly with the docking part, without the need to readjust the splicing relationship, and maintaining the design assembly intent. Through steps S100~S300, the parts in the model parts that meet the modification requirements are accurately screened, so that automated CNC processing can be achieved when subsequent parts are subjected to through-end and plane cutting. As Figure 5 The diagram below shows a free-joint connection. To facilitate processing and meet production requirements, curved parts with free ends and no cut surfaces can also be straightened by modifying control points. Furthermore, if the current curved part has free ends and no connections, there's no need to modify it to a straight line.

[0028] Furthermore, in step S300, after moving the control points of the ends of the arc-shaped parts of the through-joint / flat-joint connection, the arc-straightening operation is performed on the arc-shaped parts, including: Step S310: After moving the end control point of the arc part according to the connection type of the arc part, three control points of the arc part are respectively obtained, including a first end control point, a second end control point, and an intermediate control point, wherein the intermediate control point is a control point located between the first end control point and the second end control point, and the first end control point and / or the second end control point are the end control points of the connection end of the arc part; Step S320: Connect the first end control point and the second end control point to form a first straight line, move the intermediate control point to the first straight line, and obtain the straight part. After modification, the length of the straight part is different from that of the arc part.

[0029] Specifically, if Figure 4As shown, the center line of each arc-shaped part is composed of 3 or more control points. When the part type is modified, the first end control point and the second end control point of the arc-shaped part, that is, the starting point P1 and the end point P2 of the center line are taken, and these two points are connected to form a first straight line L1; any point P3 other than P1 and P2 on the center line of the arc-shaped part is taken (preferably, a point located in the middle of P1 and P2), and P3 is moved to the first straight line L1 formed by P1 / P2, and the remaining points on the arc except P1 / P2 / P3 are deleted; the two points P1 and P3 form a second straight line L2, and the two points P3 and P2 form a third straight line L3, and L2 and L3 are merged into a straight line segment L4. At this time, L4 is composed of three points P1, P3, and P2. It should be noted that L1 and L4 of the straight line segments generated in the above steps are theoretically the same. However, due to software limitations, when the original part is generated by 3 or more "points", the modified part should contain at least 3 "points" and cannot be less than 3 "points".

[0030] Furthermore, by calling the modeling software's API through Grasshopper to modify the model, only the specific part attributes or parameters that need to be modified are modified, without affecting other unrelated attributes and parameters of the part. For example, the above steps modify the centerline of the part from an arc to a straight line. The rest of the part's attributes, such as material, cross-sectional specifications, and surface treatment, remain unchanged. However, the weight and length of the part will be affected by the change from arc to straight. The modeling software will automatically calculate the modified part weight and length based on the modified straight line segment.

[0031] Preferably, when the end control point of the arc-shaped part is moved, the movement is performed along the center line of the arc-shaped part to ensure the geometric continuity of the modified part.

[0032] Optionally, after identifying the arc parts in the first parts set, the arch height of each arc part is obtained, and the arc parts that meet the preset arch height requirements are screened into the second parts set. According to production and design requirements, the arch height can be used as a screening condition for arc parts when identifying and screening arc parts.

[0033] Example 1 Based on steps S100 to S300 in the above specific implementation, this embodiment 1 provides a specific method implemented in Grasshopper, including the following steps: 1. Screening of tube parts Use secondary developed components to obtain all model entities. Use secondary developed components and built-in components to extract cross-sectional information for each entity (for example, obtain part cross-sectional type, part cross-sectional diameter, part wall thickness, number of control points in the part build history, etc.). Use the obtained cross-sectional type, cross-sectional diameter, and wall thickness to filter out circular tubular parts that meet the requirements.

[0034] According to production requirements, the target cross section of the middle cross bar of the handrail that needs to be modified is PD33*3, that is, a round tube with a diameter of 33mm and a wall thickness of 3mm. Therefore, after filtering by cross section, the original model of 4759 objects is filtered out to 1926 objects. Since the cross section of the middle cross bar of the handrail is PD33*3, that is, a round tube with a diameter of 33mm and a wall thickness of 3mm, after filtering by cross section, the original model of 4759 objects is filtered out to 1926 objects. The operation interface in Grasshopper is as follows Figure 6 shown.

[0035] 2. Screening of curved parts For the circular tubular part obtained in step 1, obtain the centerline and control points or use Curve to analyze the curvature of each control point on the centerline. First, use the ARC 3pt component to obtain the control points to create the part centerline and calculate the centerline radius property value.

[0036] Use the Curve Closedt Point component for analysis: If the curvature of all control points is less than a preset threshold (such as 0.001), the part is determined to be a straight part; otherwise, it is a curved part. At this time, 1468 parts that meet the requirements are filtered out from 1926 parts. Then, these 1468 parts are analyzed. The arch height range is 0-5mm. Due to the high model accuracy, the number of parts with an arch height of 0-1mm is 287, 1-2mm is 179, 2-3mm is 68, 3-4mm is 442, and 4-5mm is 492. The operation interface in Grasshopper is as follows Figure 7 、 Figure 8 As shown, there are 1466 parts with non-zero camber values ​​filtered out.

[0037] 3. Geometric relationship analysis Use the Proximity or Closest Points tool to find other parts that are very close to each end of the current arc part. These are the connecting parts. Use Surface to extract the cutting surface of the end and identify whether the cutting surface is cylindrical or flat.

[0038] For cylindrical cutting surfaces, obtain the center line of the connector (first part) of the current arc part, and use the Curve battery to move the end control point of the connecting end of the current arc part to the intersection of the center line of the current arc part and the center line of the first part; for planar cutting surfaces, use the Curve battery to obtain the intersection of the center line of the current arc part and the cutting plane, and move the end control point of the connecting end of the current arc part to the intersection.

[0039] In addition, when the end is free and uncut and is connected to the third part by free splicing, the current arc part can be modified into a straight part by directly moving the control point.

[0040] 5. Modify the arc segment to a straight line segment Modify the arc parts obtained by steps 1 to 4. Based on the steps S310 to S320 in the above embodiment, modify the control points to convert the original arc parts into straight parts. Figure 9 As shown, by calling the modeling software's API through Grasshopper to modify the model, only the specific part attributes or parameters that need to be modified are modified, without affecting other unrelated attributes and parameters of the part. For example, the above steps modify the centerline of the part from an arc to a straight line. The rest of the part's attributes, such as material, cross-sectional specifications, and surface treatment, remain unchanged. However, the weight and length of the part will be affected by the change from arc to straight. The modeling software will automatically calculate the modified part weight and length based on the modified straight line segment.

[0041] The embodiment of the present application also provides a batch modification system 200 for arc parts. The batch modification system method of arc parts provided in this embodiment is based on a batch modification system for arc parts. Figure 10 FIG. 1 is a schematic diagram of the architecture of a batch modification system 200 for arc-shaped parts, comprising: The annular part screening module 201 is configured to traverse all parts of the current model and, based on parameter information of each part, screen parts having a circular cross-section type and meeting preset parameter requirements as a first part set, where the parameter types in the preset parameter requirements include cross-section outer diameter and wall thickness; The arc-shaped parts screening module 202 is configured to traverse the parts in the first part set, identify the arc-shaped parts in the first part set, and screen the arc-shaped parts into a second part set, wherein the center lines of the arc-shaped parts are circular arcs with a constant curvature. The part type modification module 203 is used to perform geometric relationship judgment on each of the arc-shaped parts in the second part set, and based on the geometric relationship judgment result, modify the arc-shaped part into a straight-shaped part, wherein the center line of the straight-shaped part is a straight line: If at least one end of the arc-shaped part is connected to the first part, when the connection type is a through-end connection and the cutting surface of the arc-shaped part is a cylindrical surface, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the center line of the first part, and the arc-shaped part is modified to a straight part; if at least one end of the arc-shaped part is connected to the second part, when the connection type is a flat-end connection and the cutting surface of the arc-shaped part is a plane, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the plane cutting surface, and the arc-shaped part is modified to a straight part.

[0042] The embodiments of the present application achieve the following technical effects: 1. This application uses 3D software and Grasshopper to provide a systematic solution for process automation that integrates intelligent recognition, precise geometric calculation, and automatic modification. This solution transforms the "curved to straight" operation that originally required designers to perform manually, one by one, into a fully automatic batch process. This greatly improves the efficiency of through-cut cutting of parts and enables CNC automation equipment to completely replace manual cutting. 2. Automated processing based on precise geometric algorithms in the part identification and screening stages eliminates the inevitable human errors in manual lofting, line drawing, and cutting when modifying curved parts into straight parts. This improves production efficiency while ensuring part quality requirements during the design and production process, connecting intelligent BIM design and CNC machining processes.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A batch modification method for arc parts, characterized in that: include: Traversing all parts of the current model, and based on parameter information of each part, selecting parts whose cross-section type is a ring and that meet preset parameter requirements as a first part set, wherein the parameter types in the preset parameter requirements include cross-section outer diameter and wall thickness; Traversing each part in the first part set, identifying arc-shaped parts in the first part set, and filtering each of the arc-shaped parts into a second part set, wherein the center lines of the arc-shaped parts are circular arc curves with a constant curvature; Performing geometric relationship judgment on each of the arc-shaped parts in the second part set, and modifying the arc-shaped parts into straight-shaped parts according to the geometric relationship judgment results, wherein the center line of the straight-shaped parts is a straight line, wherein: If at least one end of the arc-shaped part is connected to a first part, and the connection type is a through-connection and the cutting surface of the arc-shaped part is a cylindrical surface, the arc-shaped part is modified into a straight part after the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the center line of the first part; If at least one end of the arc-shaped part is connected to a second part, when the connection type is a flat connection and the cutting surface of the arc-shaped part is a plane, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the plane cutting surface, and the arc-shaped part is modified into a straight part.

2. A batch modification method for arc parts according to claim 1, characterized in that: When the cross-section type cannot be obtained and the preset parameter requirements cannot be determined based on the parameter information of each part, the method further includes: Cutting the part at equal intervals along the length of the part using a preset plane to obtain a plurality of cross-sectional contour lines, wherein the preset plane is perpendicular to the tangent direction of the center line of the part at the cutting point; One or more fitting circles are formed based on the point set of the cross-sectional contour line, and the distance from each point on the outer cross-sectional contour line to the center of the corresponding fitting circle is obtained. If the difference between the distance from all points on the outer cross-sectional contour line to the center of the corresponding fitting circle and the radius of the fitting circle is within a preset range, and the radius of the fitting circle corresponding to the outer cross-sectional contour line of each cutting point is equal, then the interface type of the part is a circular cross-section; If the number of fitting circles formed by the cross-sectional contour line of a single cutting point is 2, the cross-sectional type of the part is a circular cross-section; The cross-sectional outer diameter and wall thickness of the part are obtained according to the cross-sectional contour line, and parts whose cross-sectional type is annular and meets the preset parameter requirements are screened as the first part set.

3. The batch modification method of arc parts according to claim 1 is characterized in that: The traversing each part in the first part set and identifying the arc-shaped parts in the first part set includes: Obtaining a radius attribute value of each part in the first part set, wherein the radius attribute value is used to represent a radius value of an arc where a center line of the part is located; If the radius attribute value is not 0, the part is determined to be an arc-shaped part; If the radius attribute value is 0, then read the number of control points of the part and determine whether each control point is located on the same straight line. If the number of control points of the part is greater than 2, then further obtain the curvature value of each control point on the curve formed by each control point, and determine whether each control point is located on the same straight line based on the curvature value. If the control points are not located on the same straight line and the curvature values ​​of the control points are equal, it is determined that the part is a curved part.

4. A batch modification method for arc-shaped parts according to claim 3, characterized in that: The determining whether the control points are located on the same straight line includes: Set a curvature threshold and obtain the relationship between the curvature value of each control point on the curve formed by the control points and the curvature threshold: If the curvature values ​​of the control points are all less than the curvature threshold, the part is judged to be a straight part; if the curvature values ​​of the control points are all greater than the curvature threshold, and the curvature values ​​of the control points are all equal, the part is judged to be an arc part.

5. The batch modification method of arc parts according to claim 1 is characterized in that: The step of modifying the arc-shaped part into a straight-shaped part comprises: After moving the end control point of the arc part according to the connection type of the arc part, three control points of the arc part are respectively obtained, including a first end control point, a second end control point, and an intermediate control point, wherein the intermediate control point is a control point located between the first end control point and the second end control point, and the first end control point and / or the second end control point are the end control points of the connection end of the arc part; The first end control point and the second end control point are connected to form a first straight line, and the intermediate control point is moved to the first straight line to obtain the straight-line part. After modification, the length of the straight-line part is different from that of the arc-shaped part.

6. A batch modification method for arc parts according to claim 5, characterized in that: Also includes: If at least one end of the arc-shaped part is connected to a third part, and the connection type is free splicing without cutting of the end, respectively obtain the first end control point, the second end control point, and the middle control point of the arc-shaped part, where the middle control point is a control point located between the first end control point and the second end control point; The intermediate control point is moved to a straight line formed by the first end control point and the second end control point to obtain the straight-line part.

7. The batch modification method of arc parts according to claim 1 is characterized in that: When the end control point of the arc-shaped part is moved, it is moved along the center line of the arc-shaped part.

8. The batch modification method of arc parts according to claim 1 is characterized in that: After the arc-shaped parts in the first part set are identified, the arch height of each of the arc-shaped parts is obtained, and the arc-shaped parts that meet the preset arch height requirements are screened as the second part set.

9. The batch modification method of arc parts according to claim 1 is characterized in that: The method is implemented based on Grasshopper.

10. A batch modification system for arc parts, characterized in that: The system is used to implement the method according to any one of claims 1 to 9, and the system includes: A ring part screening module is used to traverse all parts of the current model and, based on the parameter information of each part, screen the parts whose cross-section type is a ring and meets the preset parameter requirements as a first part set. The parameter types in the preset parameter requirements include the cross-section outer diameter and wall thickness; a curved part screening module, configured to traverse each part in the first part set, identify the curved parts in the first part set, and screen each of the curved parts into a second part set, wherein the center lines of the curved parts are circular arcs with a fixed curvature; A part type modification module is used to perform geometric relationship judgment on each of the arc-shaped parts in the second part set, and based on the geometric relationship judgment result, modify the arc-shaped part into a straight-shaped part, wherein the center line of the straight-shaped part is a straight line: If at least one end of the arc-shaped part is connected to the first part, when the connection type is a through-end connection and the cutting surface of the arc-shaped part is a cylindrical surface, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the center line of the first part, and the arc-shaped part is modified to a straight part; if at least one end of the arc-shaped part is connected to the second part, when the connection type is a flat-end connection and the cutting surface of the arc-shaped part is a plane, the end control point of the connecting end of the arc-shaped part is moved to the intersection of the center line of the arc-shaped part and the plane cutting surface, and the arc-shaped part is modified to a straight part.

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