Arc-shaped part machining method and system

Abstract

The invention provides an arc part machining method and system. The method comprises the steps that parameter information of all parts is extracted, the parts are divided into different types of part sets according to material specifications and grades, and arc feature recognition is conducted on the basis of geometric information to obtain different types of arc part sets; the opening orientation of each arc-shaped part is recognized, and each arc-shaped part set is divided into two first-level groups according to the opening orientation; the bending radius fluctuation range of each arc-shaped part in the group is calculated based on the preset arch height machining error requirement, the arc-shaped parts with the bending radius fluctuation ranges intersecting are divided into the same second-level group, and the common bending radius is determined; and nesting is conducted according to the raw material length, the clamping loss and the common bending radius to generate a machining schedule. According to the method and the device, full-process automation of identifying the arc-shaped parts from the three-dimensional model, judging the opening orientation and generating the grouping processing plan table is realized, and the raw material utilization rate and the processing efficiency are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of computer-aided design and manufacturing, in particular to a machining method and system for arc-shaped parts. BACKGROUND

[0002] In the fields of large steel structure buildings, shipbuilding, large equipment installation, etc., arc-shaped profiles are widely used as key load-bearing or modeling structural components. With the continuous improvement of product manufacturing precision, production cycle and cost control requirements in these fields, the machining efficiency and material utilization rate during the machining of arc-shaped parts have become key indicators restricting the upgrading of industry capacity.

[0003] In the prior art, the machining of linear parts mostly adopts one-cut or simple cutting process, and the machining process is mature and the process loss rate is extremely low. The machining of arc-shaped parts needs to go through multiple processes such as bending forming and cutting. Due to the need to adapt to the special parameters of the arc-shaped profile in the forming process, the machining complexity is much higher than that of linear parts, and additional process loss is inevitable. The current workshop machining process for arc-shaped parts still has two technical pain points that need to be solved urgently: First, the acquisition efficiency of machining parameters is low and the error rate is high. The workshop needs to rely on manual reading of two-dimensional or three-dimensional model information in the machining plan drawing, identifying and counting each arc-shaped profile's bending radius, opening direction, arc length, cross-sectional size and other key machining parameters one by one, and then manually entering them into the machining equipment control system. This process not only consumes time and effort, but also is prone to errors due to visual fatigue and misinterpretation of the drawing, such as confusion of the opening direction and incorrect recording of the bending radius, which can cause subsequent machining parts to be scrapped and seriously affect the machining efficiency and product qualification rate. Second, the utilization rate of raw materials is low and the flexibility of the machining plan is poor. Due to the limitations of the machining process and equipment control method, the workshop can currently only use one raw material to process arc-shaped parts with the same bending radius, and the clamping and fixing areas at both ends of the raw material need to be cut off as waste during the machining process because they cannot adapt to the arc forming requirements. At the same time, when manually developing a machining plan, it is difficult to flexibly combine the bending radius, arc length, opening direction and other parameters of different arc-shaped parts, making it impossible to achieve the optimal arrangement of multiple-specification arc-shaped parts on the same raw material, further limiting the utilization rate of raw materials, which is only 65%-70% for conventional utilization, much lower than the more than 90% for linear parts, resulting in a large amount of raw material waste and increased manufacturing costs. In summary, the technical defects of the existing arc-shaped part machining process in terms of machining parameter acquisition and raw material utilization have made it difficult to meet the current manufacturing industry's demand for efficient and low-cost machining, and there is an urgent need for a machining method for arc-shaped parts that can automatically identify machining parameters and optimize machining task combinations to solve the above technical problems. SUMMARY

[0004] The application provides a processing method and system of an arc-shaped part to solve the problems of low efficiency and high error rate in obtaining processing parameters, low utilization rate of raw materials and poor flexibility of processing plans in the prior art.

[0005] In a first aspect, the disclosure provides a processing method of an arc-shaped part, the method comprising: obtaining a three-dimensional model of a target processing plan, analyzing and extracting parameter information of all parts from the three-dimensional model, the parameter information including material information and geometric information; dividing all parts into different categories of part sets according to material specifications and grades based on the material information, and identifying arc-shaped features of each category of part sets based on the geometric information to obtain different categories of arc-shaped part sets; identifying the opening direction of each arc-shaped part, and dividing each arc-shaped part set into two first-level groups according to the different opening directions, the opening direction including: facing the center direction and facing away from the center direction, the center being the center of the arc-shaped part; For each first-level group, calculate the bending radius fluctuation range of each arc-shaped part in the group based on the preset arch height processing error requirement, divide the arc-shaped parts with the intersection of the bending radius fluctuation range into the same second-level group, and determine a common bending radius for each second-level group. For each second-level group, generate a processing plan table according to the raw material length, clamping loss and the common bending radius, the processing plan table being used to guide the processing of multiple arc-shaped parts using the common bending radius on the same raw material.

[0006] According to the processing method of the arc-shaped part provided by the disclosure, the geometric information includes first geometric information or second geometric information; the parameter information of all parts is analyzed and extracted from the three-dimensional model, including: if the three-dimensional model is a building information model containing parameterized attributes, connecting with the application programming interface of the software for establishing the building information model to directly read the material information and the first geometric information of each part, the first geometric information including part length, control point position, control point number and part radius attribute; or, if the three-dimensional model is a geometric model without parameterized attributes, the material information and the second geometric information of all parts are extracted by reading and analyzing the geometric model, the second geometric information including part length, control point position and control point number.

[0007] According to the processing method of the arc-shaped part provided by the disclosure, the arc-shaped feature identification includes: identifying the arc-shaped part based on the control point number and the part radius attribute, or identifying the arc-shaped part based on the control point number and the control point position by using a geometric fitting algorithm.

[0008] According to the processing method of the arc-shaped part provided in this disclosure, the opening orientation includes: facing the center and facing away from the center; the identification of the opening orientation of each arc-shaped part specifically includes: determining the bending radius of each arc-shaped part based on the geometric information of each arc-shaped part; extracting the center line of each arc-shaped part and calculating the center bending radius corresponding to each center line; determining the opening orientation of each arc-shaped part based on the size of the bending radius and the center bending radius, wherein if the bending radius is greater than the center bending radius, the opening orientation is facing the center, and if the bending radius is less than the center bending radius, the opening orientation is facing away from the center.

[0009] According to the processing method of the arc-shaped parts provided in this disclosure, the step of calculating the bending radius fluctuation range of each arc-shaped part in each first-level group based on a preset arch height processing error requirement, dividing the arc-shaped parts whose bending radius fluctuation ranges have an intersection into the same second-level group, and determining a common bending radius for each second-level group includes: calculating the bending radius fluctuation range of each arc-shaped part in each first-level group based on a preset arch height processing error requirement; determining whether there is a unique common subset of the bending radius fluctuation ranges of all arc-shaped parts in the group; if there is, dividing all arc-shaped parts in the group into a second-level group; if not, determining the number of second-level groups and the second-level grouping result based on the intersection of the bending radius fluctuation ranges of each arc-shaped part in the group; and determining a common bending radius for each second-level group.

[0010] According to the processing method of the arc-shaped parts provided in this disclosure, the step of calculating the bending radius fluctuation range of each arc-shaped part in each first-level group based on a preset arch height processing error requirement includes: extracting the arc length and bending radius of each arc-shaped part according to the geometric information of each arc-shaped part, and calculating the actual arch height of each arc-shaped part according to the arc length and bending radius; calculating the theoretical arch height allowable range of each arc-shaped part according to the preset arch height processing error and the actual arch height; and solving the bending radius fluctuation range corresponding to the bending radius according to the theoretical arch height allowable range and the arc length.

[0011] According to the processing method of the arc-shaped part provided in this disclosure, the step of determining the number of second-level groups and the result of second-level grouping based on the intersection of the bending radius fluctuation range of each arc-shaped part in the group includes: calculating the maximum number of non-overlapping intervals of all bending radius fluctuation ranges in the group as the number of second-level groups; sorting all bending radius fluctuation ranges in the group from smallest to largest to obtain a sorted sequence of bending radius fluctuation ranges; constructing second-level groups for dividing the bending radius fluctuation ranges according to the number of second-level groups, and initializing each second-level group; based on the sorted sequence of bending radius fluctuation ranges, sequentially traversing each second-level group and updating the second-level group when the merging condition is met, until all bending radius fluctuation ranges have been grouped into second-level groups.

[0012] According to the processing method of the arc-shaped part provided in this disclosure, the material information includes material specifications and material grade; the type of raw material includes finished raw material and sheet material, and the fixed length of the raw material includes fixed length and customized length.

[0013] According to the processing method of the arc-shaped parts provided in this disclosure, the step of generating a processing plan table for each second-level group based on the material length, clamping loss, and the common bending radius includes: for each second-level group, determining the category and clamping loss of the target material based on the material information of any arc-shaped part in the group, determining the initial length of the target material based on the processing capacity of the workshop equipment; calculating the sum of the arc lengths of all arc-shaped parts in the group; determining the required quantity of the target material based on the sum of the arc lengths and the clamping loss, and calculating the utilization rate of processing at least one arc-shaped part on each target material, and generating a new processing plan table based on the arc-shaped part allocation results when the utilization rates of all target materials meet the preset conditions.

[0014] Secondly, this disclosure also provides a machining system for arc-shaped parts, the system comprising: The model parsing unit is used to obtain a three-dimensional model of the target machining plan, and to parse and extract parameter information of all parts from the three-dimensional model. The parameter information includes material information and geometric information. The feature grouping unit is used to divide all parts into different categories of parts based on the material information according to the material specifications and grades, and to perform arc feature recognition on each category of parts based on the geometric information to obtain different categories of arc-shaped parts sets. Orientation grouping unit, used to identify the opening orientation of each arc-shaped part, and divide each arc-shaped part set into two first-level groups according to the different opening orientations, the opening orientations including: facing the center and facing away from the center, the center being the center of the arc-shaped part; The radius grouping unit is used to calculate the bending radius fluctuation range of each arc-shaped part in each first-level group based on the preset arch height processing error requirement, divide the arc-shaped parts with overlapping bending radius fluctuation ranges into the same second-level group, and determine a common bending radius for each second-level group. The processing planning unit is used to generate a processing plan table for each second-level group based on the raw material length, clamping loss and the common bending radius. The processing plan table is used to guide the processing of multiple arc-shaped parts using the common bending radius on the same raw material.

[0015] In summary, the processing method and system for arc-shaped parts disclosed herein deeply integrates three-dimensional models, geometric algorithms, and optimized nesting strategies to form a highly intelligent and precise processing preparation method and system for arc-shaped parts. This system can quickly and accurately divide multiple arc-shaped parts of different specifications, grades, orientations, and bending radii into multiple groups that can be processed together, providing a powerful technical tool for the digital transformation and cost reduction and efficiency improvement of the building steel structure industry.

[0016] The processing method for arc-shaped parts disclosed herein first automatically extracts and filters out arc-shaped parts corresponding to various types and grades of steel profiles from the 3D model corresponding to the processing plan. Simultaneously, it quickly obtains information such as the arc length and bending radius of each arc-shaped part by analyzing its geometric features. Then, based on the magnitude of the bending radius between different control points on the arc-shaped part, it automatically determines the opening orientation of the arc-shaped part. By converting the processing requirements of each part from an absolute bending radius value to a flexible radius range, it quickly achieves the grouping of arc-shaped parts for processing. Finally, after grouping the arc-shaped parts into first-level and second-level groups according to the opening orientation and bending radius fluctuation range, it optimizes the nesting method within each second-level group. With the goal of minimizing the number of raw materials and maximizing the utilization rate of a single raw material, it generates an optimal processing plan, greatly improving raw material utilization and processing efficiency. It also fully considers the complexities of actual workshop conditions and has good adaptability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a method for machining an arc-shaped part provided in this disclosure; Figure 2This is a schematic diagram of the cross-section of a typical open-section steel part provided in this disclosure; Figure 3a , Figure 3b and Figure 3c This is a schematic diagram of the complete arithmetic unit group for arc feature recognition provided in this disclosure; Figure 4a This is a flowchart illustrating the method for identifying the opening orientation of each arc-shaped part provided in this disclosure; Figure 4b This is a schematic diagram of an arc-shaped part provided in this disclosure; Figure 4c This is a schematic diagram of another arc-shaped part provided in this disclosure; Figure 5 This is a schematic diagram of the complete set of arithmetic units for identifying the opening orientation of each arc-shaped part, as provided in this disclosure; Figure 6 This is a flowchart illustrating a method for dividing a second-level group as provided in this disclosure; Figure 7 This is a schematic diagram of the complete arithmetic unit group for calculating the range of bending radius fluctuations provided in this disclosure; Figure 8 This is a schematic diagram of the structure of a machining system for arc-shaped parts provided in this disclosure. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0020] Grasshopper (GH for short) is a visual programming language that runs on the Rhino 3D modeling platform and possesses cross-domain technical characteristics: on the one hand, its core functions focus on data-driven design, enabling direct transformation from design logic to visual results; on the other hand, its technical boundaries overlap with the field of interaction design, meeting the interaction needs between people and systems during the design process and solving the technical pain point of "disconnect between design logic and interactive feedback" in traditional design. It is a key tool in the current field of data-driven design that combines the dual advantages of "visual programming" and "cross-domain adaptation".

[0021] GH is not only applicable to data-driven design scenarios, but can also be extended to the steel processing stage in workshops. The processing method for arc-shaped parts proposed in this disclosure uses GH to automatically extract the parameter information of the parts based on the 3D model, automatically filter the arc-shaped parts corresponding to different types and grades of steel based on the parameter information, automatically identify the opening orientation of the arc-shaped parts and group them, automatically calculate the bending of the arc-shaped parts and group them according to the bending radius, and output the optimal processing plan table for nesting, etc., avoiding errors in the manual conversion process, reducing the number of mold changes, improving the utilization rate of raw materials, thereby improving the processing efficiency and accuracy of the parts.

[0022] Figure 1 This is a flowchart illustrating a method for machining an arc-shaped part provided in this disclosure. The method is based on Grasshopper, that is, using the Grasshopper plugin, a relevant battery pack is constructed according to the arc-shaped part machining method provided in this disclosure to achieve the machining of the arc-shaped part.

[0023] See Figure 1 The method includes: Step S11: Obtain the three-dimensional model of the target machining plan, and parse and extract the parameter information of all parts from the three-dimensional model. The parameter information includes material information and geometric information.

[0024] In this context, a target manufacturing plan refers to a production task designed for a specific production task, such as the data set of all parts required for a construction project or a product component. The 3D model of the target manufacturing plan can be a 3D digital model containing rich parametric information such as the geometry, material information, and spatial relationships of all parts, or it can be a non-parametric, purely geometric 3D digital model.

[0025] The material information refers to the relevant information of the materials corresponding to each part, including material specifications and material grades. The material specifications indicate the type and cross-sectional specifications of the steel profile corresponding to the part. The steel profile type refers to various open steel profiles produced by cold bending forming process, including channel steel, angle steel, T-shaped steel, Z-shaped steel, H-shaped steel, I-shaped steel, etc. The corresponding cross-sectional shapes include C-shaped, L-shaped, T-shaped, Z-shaped, H-shaped, I-shaped, etc.

[0026] Figure 2 This is a schematic diagram of the cross-section of a typical open-section steel part provided in this disclosure. See also... Figure 2 The four cross-sectional shapes shown are, in order, the C-shaped cross-section of channel steel, the L-shaped cross-section of angle steel, the Z-shaped cross-section of Z-shaped steel, and the T-shaped cross-section of T-shaped steel.

[0027] Furthermore, based on the material specifications, the cross-sectional shape, dimensions, weight, and technical requirements of various types of steel profiles can be determined. For example, material specification C12 indicates channel steel with a C-shaped cross-section and a cross-sectional height of 120mm. The material grade indicates the steel grade of the part, which is generally Q235B grade steel.

[0028] The geometric information refers to the geometric information such as the shape and length of the part when it is drawn, such as the position, number and radius attributes of the control points used when drawing a part, or the position and number of multiple control points when drawing a part, or the geometric information such as the number and position of control points and the length of the part obtained by parsing a drawn part.

[0029] Specifically, it is understandable that because different software is used in the design, process planning, and manufacturing stages, data cannot flow seamlessly between these stages. The 3D models designed by designers based on actual operational needs typically contain rich parametric information. Software tools used to process machining plans or 3D models generally only have basic model processing functions, making it difficult for downstream machining software to directly and losslessly utilize them. During the machining stage, manual interpretation and data entry into tables are often required to statistically analyze part information. This process is inefficient and prone to human error. Therefore, a method is needed to automatically parse and extract part parameter information from 3D models.

[0030] Specifically, it can also be understood that since the machining plan is provided by the customer, and different customers use different software to build the model in designing the machining plan, although the source model may be a 3D model containing rich parameter information, sometimes, due to requirements such as design cost, data confidentiality, and software compatibility, customers can only provide a non-parametric, purely geometric model. In this case, it is necessary to perform geometric analysis on the purely geometric 3D model to statistically analyze the parameter information of the part. Therefore, different methods are needed to extract the part parameter information for 3D models containing rich parameter information and purely geometric 3D models.

[0031] In some embodiments, if the customer provides a building information model containing parametric attributes, that is, a three-dimensional model containing rich parameter information, the Grasshopper plugin can be used to directly call the application programming interface of the target software, that is, to connect with the application programming interface of the software that created the building information model. Thus, when the target software displays the current building information model, the relevant parameters of all parts contained in the model can be directly read from the target software, including but not limited to the material information of each part and the geometric information such as the part position, part length, control point position, number of control points, and part radius attribute when designing each part.

[0032] In other embodiments, if the customer provides a geometric model that does not contain parametric attributes, that is, a non-parametric pure geometric 3D model, then it is necessary to first obtain the geometric model, and extract the material information and second geometric information of all parts by reading and parsing the geometric model. For example, first read and display the geometric model on the Rhino platform, and then parse the geometric model to perform cross-sectional geometric analysis on each part to determine its material specifications, identify the additional identification information in the geometric model to determine the material grade, and determine the size information of each part through geometric calculations, etc.

[0033] The process of determining the material specifications of each part through cross-sectional geometric analysis includes: cutting the part along its length to obtain a cross-sectional profile; matching the cross-sectional profile with a profile in a standard steel database; if the match is successful, the material specification is determined to be a specific specification and model in the national standard steel; if the match is unsuccessful, the material specification is determined to be non-standard and can be customized according to the cross-sectional shape and size. The additional identification information includes, but is not limited to, colors, layers, or label text used to indicate different steel grades of the part. In this case, identifying the additional identification information in the geometric model to determine the material grade refers to determining the corresponding steel grade through the additional identification information of the part in the 3D model. The dimensional information of each part is determined through geometric calculations, including: taking the distance between the two ends of the outer boundary line of the part as the part length; and fitting multiple control points evenly distributed on the part with a circular arc, using the radius of the fitted arc as the bending radius.

[0034] Furthermore, the geometric information includes first geometric information or second geometric information; parsing and extracting parameter information of all parts from the three-dimensional model includes: Step 111: If the 3D model is a Building Information Model (BIM) containing parametric attributes, then connect to the application programming interface (API) of the software that created the BIM model to directly read the material information and first geometric information of each part. The first geometric information includes part length, control point position, number of control points, and part radius attribute; or... Step 112: If the three-dimensional model is a geometric model without parametric attributes, then extract the material information and second geometric information of all parts by reading and parsing the geometric model. The second geometric information includes part length, control point position and number of control points.

[0035] In step 111, the material information and first geometric information of each part are directly read. That is, the material specifications, material grade, and the number, position, and radius attributes of the control points used when drawing each part are directly read. For example, an arc can be drawn by two control points and a non-zero radius, or it can be drawn directly by three control points. The part length in the first geometric information refers to the length of the part, such as the arc length and bending radius of the arc-shaped channel steel part. The arc length is the length of the longest arc side on the geometric contour of the arc-shaped channel steel part. The bending radius can be the distance from the center to the flange tip or the distance from the center to the web. In this disclosure, the bending radius is uniformly defined as the distance from the center to the vertical plate. For example, the bending radius of the channel steel part is the distance from the center to the web, the bending radius of the T-shaped steel part is the distance from the center to the flange, and the bending radius of the angle steel part is the distance from the center to the vertical flange, etc.

[0036] In step 112, extract the material information and second geometric information of all parts. That is, based on the displayed geometric model, select three points uniformly along the length of any part as control points, and cut at the three control points to obtain the cross-sectional profile. Determine the material specification of the current part as the type of steel section based on the cross-sectional shape, and determine the size of the steel section based on the cross-sectional dimensions.

[0037] It should be noted that in step 112, three points are evenly selected along the length of the part, generally one point at the beginning, one point at the end, and one point in the middle of the control line on the back of the part. The cross-sectional analysis can be performed at the middle point. It is not necessary to perform cross-sectional analysis at all three points. At the same time, the control point at the beginning can be selected at the end face of the beginning of the part, and the control point at the end can be selected at the end face of the end of the end of the part.

[0038] Step S12: Based on the material information, all parts are divided into different categories of parts sets according to material specifications and grades, and the arc feature is identified for each category of parts set based on the geometric information to obtain different categories of arc-shaped parts sets.

[0039] Specifically, it is understood that existing software for processing machining plans or 3D models lacks dedicated tools for automated identification and feature extraction of curved parts. Therefore, this disclosure proposes a method for grouping parts by steel type and grade, and for identifying curved features. Classifying all parts can be done by reading material specification information, first determining the steel type based on the first letter of the material specification information, then determining the cross-sectional dimensions based on the material specification information, and finally determining the steel grade corresponding to the part based on the material grade information. If the actual project only requires accurate machining of a specific type of steel part, then there is no need to classify all parts. The target type of part can be directly filtered based on the first letter of the material specification information. If the target type of part is a channel steel part, then parts starting with the letter C are filtered; if the target type of part is an angle steel part, then parts starting with the letter L are filtered; if the target type of part is a T-shaped steel part, then parts starting with the letter T are filtered; if the target type of part is a Z-shaped steel part, then parts starting with the letter Z are filtered. As for arc feature recognition, since drawing an arc requires two control points plus the bending radius or three or more control points to form an arc, the control point situation of the part can be analyzed. For example, it can be determined whether the radius attribute of the control point is zero or empty, and whether the number of control points is equal to two or greater than two, so as to determine whether it is an arc part.

[0040] Furthermore, based on the material information, all parts are divided into different categories of parts sets according to material specifications and grades, and based on the geometric information, arc feature recognition is performed on each category of parts set to obtain different categories of arc-shaped parts sets, including: Step S121: Based on the material information, all parts are divided into different categories of parts sets according to material specifications and grades.

[0041] Since the same type of steel profile parts are subdivided into various specifications based on different cross-sectional dimensions, and even parts with the same material specification may have different material grades, it is necessary to classify the parts according to their material specifications and grades in order to group parts of the same category together. That is, based on the material information, all parts are classified according to their material specifications and grades. This includes: reading the material specification information from the material information and identifying the first letter of the material specification information; filtering parts of various steel profile types based on the first letter of the material specification information; reading the material grade information from the material information and determining different grades for each type of steel profile part based on the material grade. For example, among all parts with material specification information C12, there are multiple parts with grade Q235B and multiple parts with grade Q355B. Therefore, the multiple parts with material specification information C12 and grade Q235B need to be grouped into one category, and the parts with material specification information C12 and grade Q355B need to be grouped into another category.

[0042] Step S122: Based on the geometric information, perform arc feature recognition on each category of part set to obtain different categories of arc part sets.

[0043] Due to differences in geometric information, the geometric information and judgment methods used in the identification of arc features are also different. Moreover, since the bending angle of some arc parts is small, it is almost equivalent to that of straight parts. In this case, straight parts can be used to replace such arc parts. Therefore, when identifying arc parts, it is necessary to further judge the degree of bending based on the arch height of the part. For example, arc parts whose arch height meets the straightening condition are classified as straight parts. The straightening condition includes that the arch height of the part is less than or equal to the arch height threshold, which is generally taken as 1 mm.

[0044] Specifically, the arc feature recognition includes: identifying arc-shaped parts based on the number of control points and the part radius attribute, or identifying arc-shaped parts using a geometric fitting algorithm based on the number of control points and the position of the control points. The step of performing arc feature recognition on each category of part sets based on the geometric information includes: if the geometric information is first geometric information, then identifying arc-shaped parts based on the number of control points and the part radius attribute; if the geometric information is second geometric information, then identifying arc-shaped parts using a geometric fitting algorithm based on the number of control points and the position of the control points.

[0045] When the geometric information is the first geometric information, the geometric information includes the radius attribute. At this time, for parts with two control points and a non-zero radius attribute, it is necessary to further calculate the arch height of the parts. Parts with an arch height greater than the arch height threshold are identified as arc-shaped parts. For parts with more than two control points, an empty radius attribute, and any three control points can form an arc, a geometric fitting algorithm is used to calculate the fitted arc radius and arch height of any three control points that can form an arc. Parts with a fitted arc radius of non-zero and an arch height greater than the arch height threshold are identified as arc-shaped parts.

[0046] When the geometric information is the second geometric information and does not include the radius attribute, at least three control points that are evenly distributed along the length direction of any part need to be selected, and an arc needs to be fitted to the at least three control points. The radius and camber of the fitted arc need to be calculated, and the part with a non-zero fitted arc radius and an camber greater than the camber threshold needs to be identified as an arc-shaped part.

[0047] It should be noted that the arc-shaped parts disclosed herein refer to arc-shaped parts with a single bending radius. This is because in actual machining tasks, each part is generally an arc with a single bending radius, and there is no situation where a part has multiple different bending radii that can be bent into a wavy line. If in other actual engineering projects a part does have multiple different bending radii, the parts with different bending radii can be cut off first, and the cut parts can be processed according to the arc-shaped part processing method provided in this disclosure to obtain multiple individual arc-shaped parts. Finally, they can be spliced ​​together according to the drawings to obtain parts with different bending radii.

[0048] Figure 3a , Figure 3b and Figure 3c This is a schematic diagram of the complete arithmetic unit group for arc feature recognition provided in this disclosure, wherein... Figure 3a It is the part that controls the quantity of parts. Figure 3b It is to identify the curved features of the parts. Figure 3c This involves merging parts with an arch height greater than 1mm into an arc-shaped part section. Taking channel steel parts as an example, when implementing the "arc-shaped feature recognition for each category of part set" method in step S122 using Grasshopper, the specific layout of each part's arithmetic unit can be found in [link to relevant documentation]. Figure 3a , Figure 3b and Figure 3c In other words, the complete operator for arc-shaped feature recognition includes: (1) Select the object. The object can be a target part in the 3D model, such as a channel steel part; (2) Use the Deconstruct Beam component to decompose the object properties, that is, decompose the outline of the channel steel part; use the Explode Curve component to decompose the curve and extract the control points, that is, the vertices of the control lines of the web and back of the channel steel part; use the List Length component to store the control points and calculate the list length, that is, count the number of control points of the web control lines; then use the Larger Than component to compare the size, that is, compare the size of the first number "number of control points of the web" and the second number "2", and use the result of the quantity judgment as the splitting mode of the subsequent list splitting; (3) Using the Dispatch component, the target parts are divided into “parts with three or more control points” and “parts with two control points” based on the number of control points in the split mode of the list of stored objects.

[0049] (4) For the object "parts with three or more control points", the Deconstruct Beam component is used to decompose the object properties; the Explode Curve component is used to decompose the curve and extract the control points; the List Item component is used to extract the objects in the list of stored control points, namely the three control points of the web and back control lines of the channel steel part; the Arc 3pt component is used to draw an arc at three points, that is, to draw an arc at the three control points to obtain the arc curve; at the same time, for the web of the channel steel part, the Line component is used to draw a line at two points and the Curve Middle component is used to extract the midpoint of the curve, that is, to extract the midpoint of the perpendicular line of the part; then the Curve Closest Point component is used to calculate the distance from the midpoint of the curve to the arc, that is, the arch height of the part; then the LargerThan component is used to compare the size, that is, to compare the first number "arch height" with the second number arch height threshold "1mm"; finally, the Dispatch component is used to divide the list of stored "parts with three or more control points" into list A "parts with three-point arc arch height greater than 1mm" and list B "parts with three-point arc arch height less than or equal to 1mm"; (5) For the object "parts with two control points", first determine whether the radius attribute of the part is 0 and then determine whether the arch height is greater than 1mm. That is: use the Object Get Part Attribute component to get the radius attribute RADIUS of the object, use the cMode component to output the radius of the part, use the Equality component to determine whether the first number "radius attribute" is equal to the second number "0", and then use the Dispatch component to split the list of parts storing two control points into the list "parts with two control points and radius attribute of 0" and the list "parts with two control points and radius attribute of non-zero"; at the same time, use the Object Get Part Attribute component to get the arc length attribute of the object, use the judgment result of the radius attribute of the Equality component as the splitting mode, use the two Dispatch components to split the list "radius of parts with two control points and radius attribute of non-zero" and the list "arc length of parts with two control points and radius attribute of non-zero" respectively, and then use the Eval component of the formula calculation in combination with the formula. Calculate the arch height of the part, then use the Larger component to compare the first number "arch height" with the second number "arch height threshold 1mm". Finally, use the Dispatch component to further subdivide the list "parts with two control points and radius attribute not equal to 0" into list A "parts with arch height greater than 1mm" and list B "parts with arch height less than or equal to 1mm".

[0050] (6) Use the Merge component of the merge list to merge the list "parts with three-point arc arch height greater than 1mm" from step (4) and the list "parts with two control points and radius attribute not equal to 0" from step (5) and output them as arc-shaped parts.

[0051] Step S13: Identify the opening orientation of each arc-shaped part, and divide each set of arc-shaped parts into two first-level groups according to the different opening orientations. The opening orientations include: facing the center and facing away from the center, where the center is the center of the arc-shaped part.

[0052] Specifically, it can be understood that each set of curved parts corresponds to a category of curved parts, such as a set of curved parts with a cross-sectional specification of C12 and a grade of Q325B. Since the opening orientations of all curved parts in each set of curved parts are different, for axisymmetric curved parts, regardless of whether their opening orientations are the same or different, as long as they belong to the same category, they can be further grouped according to the bending radius of the parts. For non-axisymmetric curved parts, during processing, curved parts with the same opening orientation can be considered to be grouped together, but curved parts with different opening orientations need to be grouped according to their opening orientation first. Therefore, for axisymmetric curved parts, there is no need to perform the first-level grouping according to the opening orientation; step S13 can be skipped and step S14 can be directly executed to perform the second-level grouping according to the bending radius. For non-axisymmetric curved parts, it is necessary to identify the opening orientation of each curved part and then perform the second-level grouping according to the opening orientation.

[0053] Among them, axisymmetric arc-shaped parts refer to parts whose cross-sectional shape satisfies the axisymmetric property, such as I-beams, while non-axisymmetric arc-shaped parts refer to parts whose cross-sectional shape does not satisfy the axisymmetric property, such as channel steel, angle steel, T-beams, Z-shaped steel, etc.

[0054] The opening orientation includes: facing the center and facing away from the center, where the center refers to the center of the arc-shaped part, that is, the center of the arc corresponding to the arc determined by fitting the arc of the arc-shaped part; the opening orientation of the channel steel refers to whether the opening of the C-shaped part faces the center or faces away from the center; the opening orientation of the angle steel refers to whether the right-angle opening of the L-shaped part faces the center or faces away from the center; the opening orientation of the T-shaped steel refers to whether the web faces the center or faces away from the center; the opening orientation of the Z-shaped steel refers to the direction of the flange, which can be to determine whether the upper flange faces the center or faces away from the center, or to determine whether the lower flange faces the center or faces away from the center.

[0055] In some embodiments, before step S13, the method further includes: determining whether each set of arc-shaped parts is an axisymmetric set of arc-shaped parts based on the category information of each set of arc-shaped parts; if it is an axisymmetric set of arc-shaped parts, step S13 is skipped and step S14 is executed directly; if it is not an axisymmetric set of arc-shaped parts, step S13 is executed.

[0056] In other embodiments, the opening orientation also includes the bending direction. Direction facing the center and direction away from the center are considered vertical bending directions. The bending direction is perpendicular to the vertical bending direction. Bending is generally used to create curved effects on building facades, arched eaves, ceiling designs, etc., while vertical bending is mainly used for curved beams / arched main structures / large equipment frames / supports / curved railings / handrails. When bending, the opening of the part is perpendicular to the plane containing the arc and center of the curved part. The direction can be vertically upward or vertically downward. Taking channel steel as an example, bending refers to the channel steel part bending with its flanges as support, while vertical bending refers to the channel steel part bending with its web as support. When bending, for arc-shaped parts with the same bending radius but opening directions of either vertically upward or vertically downward, the part with the opening direction of vertically downward can be bent vertically upward and then rotated 180 degrees to obtain the desired result. In other words, the opening directions of vertically upward and vertically downward are the same when rotated 180 degrees during bending, and can be processed together. However, when bending vertically, the opening directions facing the center and facing away from the center are not symmetrical and cannot be processed together. Therefore, parts for bending can be directly grouped together without further subdividing into specific opening direction groups. Thus, the opening directions are generally divided into three categories: the first category facing the center, the second category facing away from the center, and the third category bending direction. In this case, step S13 can be: identifying the opening direction of each arc-shaped part and dividing each arc-shaped part set into three first-level groups according to the different opening directions: facing the center, facing away from the center, and bending direction.

[0057] Furthermore, taking channel steel as an example, after obtaining the part's parameter information through step 1, the first step is to determine whether the arc is a sloping bend or a vertical bend based on the web. If it is a sloping bend, the opening orientation is determined to be the third type of orientation; otherwise, it is a vertical bend, and the opening orientation belongs to the first or second type, requiring further judgment. Determining whether the arc is a sloping bend or a vertical bend based on the web specifically includes: based on the positional relationship between the web and the arc surface of the part, if the web is perpendicular to the arc surface, it indicates a vertical bend; otherwise, it is a sloping bend. The arc surface of the part refers to the plane containing the arc and its center of the arc-shaped part. For example, if the radii of two points on the web at the positions of the two flanges are different, the arc is a sloping bend, and the opening orientation belongs to the third type of orientation. If the radii of two points at the positions of the two flanges are the same, the arc is a vertical bend, and the opening orientation belongs to the first or second type, requiring further judgment. For other types of channel steel, if bending occurs in actual engineering applications, it is also necessary to first determine whether it is bending or upright. For example, for T-shaped steel, the positional relationship between its flange and the curved surface of the part is determined. Different types of parts refer to different plate surfaces when determining whether they are bending or upright, and this disclosure does not limit this.

[0058] Specifically, it can also be understood that the opening orientation of each part is determined by judging the bending radius of each part and the bending radius corresponding to its centerline. Taking a channel steel part as an example, its bending radius is defined as the distance from the center of the circle to the vertical plate of the part, that is, the bending radius of the channel steel part is the distance from the center of the circle to the web. The centerline of the part can be formed by connecting the center points of multiple sections on the part. For example, the centerline of the channel steel is the line where the center point of the rectangle corresponding to the C-shaped section is located. Then, the opening orientation is determined by judging the bending radius and the bending radius at the centerline.

[0059] Step S14: For each first-level group, calculate the bending radius fluctuation range of each arc-shaped part in the group based on the preset arch height processing error requirement, divide the arc-shaped parts with overlapping bending radius fluctuation ranges into the same second-level group, and determine a common bending radius for each second-level group.

[0060] Specifically, it can be understood that in the process of bending straight parts into arc-shaped parts by cold bending, it is necessary to change dies with different bending radii to obtain arc-shaped parts with different bending radii. Frequent die changes are a time-consuming and labor-intensive physical operation that will seriously interrupt the continuous processing flow and become the efficiency bottleneck of the entire production process. Moreover, each bending will also lead to the waste of raw materials due to the clamping of parts. Therefore, in order to reduce the number of die changes, reduce costs and achieve high utilization of arc-shaped parts, this disclosure proposes a method for grouping arc-shaped parts so that each group of arc-shaped parts is processed using a common bending radius.

[0061] Specifically, it can also be understood that step S14 specifically includes: for each first-level group, calculating the bending radius fluctuation range of each arc-shaped part in the group based on the preset arch height processing error requirements; determining whether there is a unique common subset of the bending radius fluctuation ranges of all arc-shaped parts in the group; if there is, dividing all arc-shaped parts in the group into a second-level group; if not, determining the number of second-level groups and the second-level grouping result based on the intersection of the bending radius fluctuation ranges of each arc-shaped part in the group; and determining a common bending radius for each second-level group.

[0062] Step S15: For each second-level group, generate a processing plan table by nesting materials based on the material length, clamping loss and the common bending radius. The processing plan table is used to guide the processing of multiple arc-shaped parts using the common bending radius on the same material.

[0063] Specifically, it can be understood that for each type of part, based on the opening orientation and bending radius of the curved parts, curved parts with the same opening orientation and the same common bending radius are divided into a second-level group. This allows each second-level group to process all curved parts within the group with the same bending radius. However, in actual processing, since the dimensions of the raw materials used to process the parts also differ, when the curved parts of each second-level group are processed together, it is also necessary to calculate the raw material requirements and the raw material utilization rate to ensure that the raw material utilization rate is maximized when each second-level group is processed together.

[0064] The raw materials refer to the raw materials used to process parts, and the types of raw materials include finished raw materials and sheet metal raw materials. Finished raw materials refer to straight finished products, such as finished channel steel, finished angle steel, or finished T-shaped steel, etc., which are directly used to obtain corresponding curved parts by bending. Sheet metal raw materials refer to pure steel plates, which are used to customize parts of special specifications. Pure steel plates usually need to undergo processes such as bending or welding to obtain customized parts. When using pure steel plates as raw materials, one can directly use the plate to bend the plate to obtain the target type of straight steel, and then bend the straight steel to obtain curved parts; alternatively, one can first cut the web, flanges, etc. of each part from the plate, weld them into straight parts, and then bend them to obtain curved parts; alternatively, one can directly cut the flanges into curved flanges, and then weld the curved flanges and webs together to obtain curved parts.

[0065] The raw material length refers to the standard length of the raw material, which includes fixed length and customized length. For finished raw materials or sheet materials, there are generally fixed standards. The width of finished raw materials is directly determined by their material specifications; the width of sheet materials is generally 1.5 meters, 2 meters, or 2.5 meters. Among the lengths of finished raw materials or sheet materials, 6 meters and 12 meters are currently the absolute mainstream specifications. Other common standard lengths such as 9 meters, 10 meters, 11 meters, and 13 meters are also produced. In a few cases, customized lengths can be made according to actual needs.

[0066] The clamping loss refers to the material loss caused by the machine tool fixture clamping the material during the bending process. The clamping loss includes the clamping length at both ends and the clamping length at both ends. The clamping length at both ends is generally 100mm-300mm, and the specific value can be determined based on the cross-sectional information corresponding to the material specifications and the workshop equipment. This is because different workshops use different processing equipment in actual processing, and different equipment corresponds to different fixtures. If the fixture used in the workshop equipment is fixed, that is, the clamping length during bending is fixed, then the clamping loss is directly determined based on the workshop equipment. If multiple fixtures are used in the workshop or the fixtures can be flexibly replaced, the clamping loss is determined based on the cross-sectional information corresponding to the material specifications and the workshop equipment. For example, common steel profiles such as H-beams, angle steel, and channel steel can be pre-associated with different fixtures according to their national standard models. Then, a matching fixture can be selected based on the material specifications of the parts during actual processing, and the clamping loss can be determined based on the clamping length of the fixture. This avoids material waste or processing interruption due to clamping problems and ensures stable clamping.

[0067] Specifically, it's understandable that, for convenience, workshops typically purchase finished steel that meets national standards for processing, while using pure steel plates for special customizations that don't meet national standards. Furthermore, different workshops have varying raw material processing capabilities. Therefore, when optimizing the nesting of curved parts in each second-level group, it's necessary to consider the workshop's equipment processing capabilities, such as the workshop's space and the model of the bending machine, to ensure that the length of the raw material does not exceed the workshop's equipment processing capacity. In other words, the length of the raw material needs to be greater than the lower limit of the workshop's equipment processing capacity and less than or equal to the upper limit.

[0068] In some embodiments, after determining the length of the raw material to be used, the step of generating a nesting processing schedule for each second-level group based on the raw material length, clamping loss, and the common bending radius specifically includes: Step S151: For each second-level group, determine the type and clamping loss of the target raw material based on the material information of any arc-shaped part in the group, and determine the initial length of the target raw material based on the processing capacity of the workshop equipment.

[0069] The material information includes material specifications and material grade; the types of raw materials include finished raw materials and sheet materials; and the fixed length of the raw materials includes fixed length and customized length.

[0070] Specifically, for all curved parts in each second-level group, since the second-level group is further subdivided according to the opening orientation and bending radius based on the classification by type and grade, the cross-sectional information of all parts in the second-level group is the same. At this time, by taking any curved part in the second-level group, the standard of the target raw material corresponding to the current second-level group can be determined by obtaining its material information. For example, if the material specification is C12 and the material grade is Q235B, by matching with the national standard, it is found that the material specification of the curved part in the second-level group belongs to the national standard. At this time, finished raw materials can be directly purchased for processing, that is, the raw material is finished raw material. Conversely, if the material specification of the curved part in the second-level group does not belong to the national standard, that is, non-national standard material specifications, then it is necessary to customize the curved part according to the non-national standard material specifications using sheet material.

[0071] More specifically, for all parts in each second-level group, after determining the material information of the curved parts, the type of target raw material—whether to use finished raw material or sheet material—can be further determined based on the material information. Furthermore, the clamping loss for securely holding the target raw material can be determined based on the specific cross-sectional information in the material information. Then, the initial length of the target raw material is determined based on the processing capacity of the workshop equipment, ensuring that the length of the target raw material does not exceed the upper limit of the current processing capacity. For example, if the upper limit of a workshop's equipment processing capacity is 8 meters of raw material, then the processing plan can only use 6-meter-long finished raw materials and sheet material. Or, for example, if the upper limit of a workshop's equipment processing capacity is 13 meters of raw material, then the processing plan can use 6-meter, 9-meter, and 12-meter-long finished raw materials and sheet material. In this case, the 12-meter length can be preferentially chosen because using one 12-meter length can further save material waste at both clamping ends compared to using two 6-meter lengths.

[0072] It should be noted that in some special cases, if a certain arc-shaped part is made of non-national standard material specifications, but the non-national standard material specifications are close to a certain national standard material specifications and the customer also accepts the use of the close national standard specifications for replacement, then it is also possible to directly purchase finished raw materials according to the close national standard specifications.

[0073] Step S152: Calculate the sum of the arc lengths of all arc-shaped parts in the group.

[0074] Specifically, calculate the sum of the arc lengths of all arcs within the second-level group, that is, sum the arc lengths of each arc part within the group.

[0075] Step S153: Determine the required quantity of target raw materials based on the sum of the arc lengths and the clamping loss, calculate the utilization rate of processing at least one arc-shaped part on each target raw material, and generate a new processing plan table based on the arc-shaped part allocation results when the utilization rates of all target raw materials meet the preset conditions.

[0076] Specifically, there will be a clamping loss for each raw material used, and the sum of the arc lengths of the arc-shaped parts that can be processed on each raw material can clearly and accurately reflect the utilization rate of the raw material. Therefore, in order to improve the utilization rate of raw materials, it is necessary to ensure that the number of raw materials used is as small as possible and the utilization rate of each raw material is as high as possible.

[0077] Further, in step S153, determining the required quantity of the target material based on the sum of the arc lengths and the clamping loss can be as follows: if the sum of the arc lengths is less than the difference between the initial length of the target material and the clamping loss, then the required quantity of the target material is determined to be 1. If the utilization rate of one target material is greater than a first preset utilization rate threshold, then the initial length of the target material remains unchanged; otherwise, the length of the target material is changed from the initial length to another fixed length or a customized length based on the sum of the arc lengths. The first preset utilization rate threshold can also be: if the sum of the arc lengths is greater than the difference between the initial length of the target material and the clamping loss, then the required quantity of the target material is determined to be greater than 1, and it is necessary to ensure that the utilization rate of each target material is greater than a second preset utilization rate threshold. Furthermore, when there are multiple target materials, if the utilization rate of the last material is too low, it can be replaced or customized with a material of another length based on the sum of the actual arc lengths of the remaining arc-shaped parts to avoid material waste. The first preset utilization rate threshold is generally set to 93%, and the second preset utilization rate threshold is generally set to 90%, but can also be adjusted to other values ​​according to actual needs; this disclosure does not limit this.

[0078] The aforementioned processing method for curved parts integrates three-dimensional models, geometric algorithms, and optimized nesting strategies to form a highly intelligent and refined preparation method for processing curved parts. This method can quickly and accurately divide multiple curved parts of different specifications, grades, orientations, and bending radii into multiple groups that can be processed together, providing a powerful technical tool for the digital transformation and cost reduction and efficiency improvement of the building steel structure industry. This method first automatically extracts and filters out various types and grades of curved steel corresponding to the 3D model of the processing plan. Simultaneously, it quickly obtains information such as the arc length and bending radius of each curved part by analyzing its geometric features. Then, based on the magnitude of the bending radius between different control points on the curved part, it automatically determines the opening orientation of the curved part. By converting the processing requirements of each part from an absolute bending radius value to a flexible radius range, it quickly groups the curved parts for processing. Finally, after grouping the curved parts into first-level and second-level groups based on the opening orientation and bending radius fluctuation range, it optimizes the nesting method within each second-level group. With the goal of minimizing the number of raw materials and maximizing the utilization rate of a single raw material, it generates an optimal processing plan, greatly improving raw material utilization and processing efficiency. It also fully considers the complexities of actual workshop conditions and has good adaptability.

[0079] Figure 4a This is a flowchart illustrating the method for identifying the opening orientation of each curved part provided in this disclosure. Figure 4b This is a schematic diagram of an arc-shaped part provided in this disclosure. Figure 4c This is a schematic diagram of another arc-shaped part provided in this disclosure; see also Figure 4b and Figure 4c The aforementioned arc-shaped parts are all arc-shaped channel steel parts, specifically... Figure 4b It is an arc-shaped part with its opening facing directly towards the center of the circle. Figure 4c It is an arc-shaped part with its opening facing away from the center of the circle.

[0080] See Figure 4a The method includes: Step S41: Determine the bending radius of each arc-shaped part based on its geometric information.

[0081] Specifically, if the geometric information is the first geometric information, then when the number of control points of any part is equal to 2, the bending radius of the arc-shaped part is determined according to the part radius attribute. When the number of control points of any part is greater than 2, the geometric fitting algorithm is used to calculate the fitted arc radius of the control points as the bending radius. Taking a channel steel part as an example, three control points are randomly selected on the web of any channel steel part and the fitted arc radius of the three control points is calculated as the bending radius.

[0082] SeeFigure 4b When the bending radius of a channel steel part is defined as the distance from the center to the web, the bending radius refers to the bending radius of arc A1-F1 or arc C1-I1, with point O1 as the center of arc A1-F1. The bending radius of the part is the distance from the center O1 to any point on arc A1-F1, such as the length of line segment O1-A1. When determining the bending radius of each arc-shaped part, it can be determined based on the part's radius attribute, or by arbitrarily selecting three control points to fit the arc. For example, taking... Figure 4b Points A1, E1, and F1 on the web of the middle part are used as three control points, and the fitted arc radius of the three control points A1, E1, and F1 is calculated as the bending radius.

[0083] See Figure 4c When the bending radius of a channel steel part is defined as the distance from the center to the web, the bending radius refers to the bending radius of arc A2-F2 or arc C2-I2. Point O3 is the center of the arc A2-F2. The bending radius of the part is the distance from the center O3 to any point on arc A2-F2, such as the length of line segment O3-A2. When determining the bending radius of each arc-shaped part, it can be determined based on the part's radius attribute, or by arbitrarily selecting three control points to fit the arc. For example, taking... Figure 4c Points A2, E2, and F2 on the web of the middle part are used as three control points, and the fitted arc radius of the three control points A2, E2, and F2 is calculated as the bending radius.

[0084] Step S42: Extract the centerline of each arc-shaped part and calculate the center bending radius corresponding to each centerline.

[0085] Specifically, the central bending radius is the bending radius at the centerline of the part. The centerline of each part can be formed by connecting the center points of multiple sections. For example, the centerline of a channel steel is the line containing the center point of the rectangle corresponding to the C-shaped section. The central bending radius corresponding to each centerline can be the arc radius obtained by fitting an arc to any three control points on the centerline.

[0086] See Figure 4b, the center line of the arc-shaped channel steel part is an arc formed by connecting the center points of multiple cross-sections, which is the arc connected by point M1, point M2 and point M3. M1 is the center point of the rectangle formed by the part endpoints A1, B1, C1 and D1. Point M2 is the center point of the rectangle corresponding to the cross-section at the center of the part. Point M3 is the center point of the rectangle formed by the part endpoints F1, G1, H1 and I1. Calculate the center bending radius corresponding to each center line. It can be to take point M1, point M2 and point M3 as three control points. Then the center bending radius is the radius length between the arc M1-M3 and its corresponding center of the circle, that is, the distance from the center of the circle O2 to any point on the arc M1-M3, such as the length of the line segment O2-M1. Among them, the center of the circle O1 and the center of the circle O2 are on the same vertical line.

[0087] See Figure 4c , the center line of the arc-shaped channel steel part is an arc formed by connecting the center points of multiple cross-sections, which is the arc connected by point M4, point M5 and point M6. M4 is the center point of the rectangle formed by the part endpoints A2, B2, C2 and D2. Point M5 is the center point of the rectangle corresponding to the cross-section at the center of the part. Point M6 is the center point of the rectangle formed by the part endpoints F2, G2, H2 and I2. Calculate the center bending radius corresponding to each center line. It can be to take point M4, point M5 and point M6 as three control points. Then the center bending radius is the radius length between the arc M4-M6 and its corresponding center of the circle, that is, the distance from the center of the circle O4 to any point on the arc M4-M6, such as the length of the line segment O4-M4. Among them, the center of the circle O3 and the center of the circle O4 are on the same vertical line.

[0088] Step S43, determine the opening direction of each arc-shaped part according to the size of the bending radius and the center bending radius of each arc-shaped part. If the bending radius is greater than the center bending radius, the opening direction is towards the center of the circle. If the bending radius is less than the center bending radius, the opening direction is away from the center of the circle.

[0089] Specifically, step S41 can determine the bending radius of the part, denoted as RK. Step S42 can determine the center bending radius at the center line of the part, denoted as RZ. If RK > RZ, it means the opening direction is towards the center of the circle. If RK < RZ, it means the opening direction is away from the center of the circle. See Figure 4b , the bending radius is the length of the line segment O1-A1, and the center bending radius is the length of the line segment O2-M1. The length of the line segment O1-A1 is greater than the length of the line segment O2-M1. That is, the opening direction of the part is towards the center of the circle; See Figure 4c , the bending radius is the length of the line segment O3-A2, and the center bending radius is the length of the line segment O4-M4. The length of the line segment O3-A2 is greater than the length of the line segment O4-M4. That is, the opening direction of the part is away from the center of the circle.

[0090] Figure 5This disclosure provides a schematic diagram of the complete set of arithmetic units for identifying the opening orientation of each curved part. Taking a channel steel part as an example, when implementing the method for identifying the opening orientation of each curved part in steps S41-S43 based on Grasshopper, the specific layout of each arithmetic unit can be found in [reference needed]. Figure 5 That is, the complete arithmetic unit that identifies the orientation of the opening of each curved part includes: (1) Select an object. The object can be a target part, such as any arc-shaped part in a set of arc-shaped parts; (2) Use the Object Cent Line component to obtain the center line of the object, that is, the center line of each arc part. Use the End Points component to obtain the start and end points of the center line, use the Curve Middle component to obtain the middle point of the center line, and use the Arc 3pt component to draw an arc at three points, that is, create an arc for the start, middle and end points, and obtain the radius of the arc, denoted as radius A; see Figure 4b Line segment M1-M3 is the centerline of the channel steel arc-shaped part. Point M1 corresponds to the starting point of the centerline, point M2 corresponds to the midpoint of the centerline, and point M3 corresponds to the ending point of the centerline. The radius A is the length of line segment O2-M1; see also Figure 4c Line segment M4-M6 is the centerline of the channel steel arc-shaped part. Point M4 corresponds to the starting point of the centerline, point M5 corresponds to the middle point of the centerline, and point M6 corresponds to the ending point of the centerline. The radius A is the length of line segment O4-M4.

[0091] (3) Use the Deconstruct Beam component to decompose object properties, use the Explode Curve component to decompose curves and extract control points, use the List Item component to extract objects from the list of stored control points, namely the three control points of the web and back control lines of the channel steel part, and use the Arc 3pt component to draw an arc at three points, that is, draw an arc at the three control points to obtain the radius of the arc, denoted as radius B; see [link to relevant documentation] Figure 4b Line segment A1-F1 is the control line for the web and back of the curved channel steel part. Points A1, E1, and F1 are the three control points. Radius B is the length of line segment O1-A1. See also... Figure 4c Line segment A2-F2 is the control line for the web of the channel steel arc part. Points A2, E2 and F2 are three control points. The radius B is the length of line segment O3-A2.

[0092] (4) Use the Larger Than component to compare the size, compare the size of the first number "center line radius A" and the second number "control line radius B", and then use the Dispatch component to split the object list into a list of "openings facing away from the center" with radius A greater than radius B and a list of "openings facing the center" with radius A less than radius B.

[0093] In the aforementioned method for identifying the opening orientation of each curved part, based on the asymmetrical nature of the cross-sections of steel sections of different specifications, the "part back control line" and "part center line" are selected as the judgment criteria. That is, the opening orientation of the curved part is determined by the relative size relationship of the geometric features inside the part itself, avoiding subjective judgment by manual drawing and improving the accuracy and robustness of the judgment. At the same time, corresponding radius acquisition strategies are provided for 3D models at different levels of detail: "direct reading of radius attributes" or "multi-control point geometric fitting", enhancing the applicability of the method. In addition, the automatic determination of the opening orientation of each curved part based on Grasshopper can completely liberate engineers from tedious and error-prone manual identification and judgment work, significantly shortening the data processing time before processing, which is a key link in realizing the digital intelligent manufacturing of steel structures.

[0094] Figure 6 This is a flowchart illustrating a method for dividing a second-level group according to the present disclosure. After grouping the arc-shaped parts into first-level groups based on the opening orientation, it is necessary to further group them into second-level groups based on the bending radius. That is, for each first-level group, the allowable bending radius fluctuation range of each arc-shaped part in the group is calculated when the preset arch height processing error requirement is met. Arc-shaped parts whose bending radius fluctuation ranges intersect are divided into the same second-level group, and a common bending radius is determined for each second-level group.

[0095] See Figure 6 The method for dividing into second-level groups, that is, for each first-level group, calculating the bending radius fluctuation range of each arc-shaped part within the group based on a preset arch height processing error requirement, and dividing arc-shaped parts whose bending radius fluctuation ranges overlap into the same second-level group, specifically includes the following steps: Step S61: For each first-level group, calculate the bending radius fluctuation range of each arc-shaped part in the group based on the preset arch height processing error requirements.

[0096] Specifically, it can be understood that in order to reduce the number of mold changes, the same bending radius should be used for processing each group as much as possible. This disclosure proposes to divide the same or similar bending radii into a group, calculate the radius that still meets the processing error after the bending radius changes based on the processing error, that is, calculate the bending radius fluctuation range of each arc part in the group based on the preset arch height processing error requirements, and group them based on the bending radius fluctuation range.

[0097] Specifically, it can also be understood that, for each first-level group, calculating the bending radius fluctuation range of each arc-shaped part within the group based on a preset arch height processing error requirement specifically includes: Step S611: Extract the arc length and bending radius of each arc part based on the geometric information of each arc part, and calculate the actual arch height of each arc part based on the arc length and bending radius.

[0098] The actual arch height refers to the vertical distance from the chord connecting the two endpoints of the curved section of the arc-shaped part to the apex of the arc corresponding to the midpoint of the chord. The formula for calculating the actual arch height of each arc-shaped part based on the arc length and bending radius is as follows: H represents the actual arch height, L represents the arc length of the part, and R represents the bending radius. The geometric information of each arc-shaped part can be either primary geometric information or secondary geometric information.

[0099] If the geometric information is the first geometric information, then extracting the arc length and bending radius of each arc-shaped part includes: determining the arc length of the arc-shaped part based on the length information of the first geometric information; determining the bending radius based on the part radius attribute of the first geometric information; or, after fitting the arc with the control points of the first geometric information, using the fitted arc radius as the bending radius.

[0100] If the geometric information is the second geometric information, then extracting the arc length and bending radius of each arc-shaped part includes: taking the distance between the two ends of the arc line on the outer boundary of the part as the part length, and fitting the arc to multiple control points evenly distributed on the part and taking the obtained arc radius as the bending radius.

[0101] Step S612: Calculate the theoretical allowable range of arch height for each arc-shaped part based on the preset arch height machining error and the actual arch height.

[0102] The preset arch height processing error refers to the processing accuracy of the steel structure, which is generally taken as 1mm. If the actual arch height is H and the theoretical arch height is H_c, then the theoretical arch height and the actual arch height need to satisfy |H_c - H|<= 1mm. For example, if the actual arch height of a certain arc-shaped part is 5mm, then the allowable range of its theoretical arch height is [4mm, 6mm].

[0103] Step S613: Based on the theoretical allowable range of arch height and the arc length, the range of bending radius fluctuation corresponding to the bending radius is solved.

[0104] Based on the relationship between arch height, arc length, and bending radius, with the arc length remaining constant, the range of change of the bending radius when the arch height changes is calculated as the bending radius fluctuation range [R_min, R_max]. That is, when the bending radius R of the part is between [R_min, R_max], the theoretical arch height calculated for any bending radius will not exceed the preset arch height processing error. In other words, the calculated theoretical arch height and the actual arch height satisfy the condition |H_c - H| <= 1mm.

[0105] Figure 7 This is a schematic diagram of the complete set of arithmetic units for calculating the range of bending radius fluctuations provided in this disclosure; taking a channel steel part as an example, when implementing the method of "calculating the range of bending radius fluctuations of each arc-shaped part in the group based on the preset arch height machining error requirements" in step S61 using Grasshopper, the specific layout of each arithmetic unit can be found in [reference needed]. Figure 7 In other words, the complete arithmetic unit for calculating the range of bending radius fluctuations includes: (1) Obtain the object, which is any arc-shaped part in a group of arc-shaped parts with the same category and the same opening orientation; (2) Use the Deconstruct Beam component to decompose the object properties, use the Explode Curve component to decompose the curve and extract the control points, and use the List Item component to extract the objects in the list of stored control points, namely the three control points of the web plate back control line of the channel steel part. The three control points correspond to the first control point, the middle control point and the last control point. Use the Arc 3pt component to draw an arc at 3 points, that is, draw an arc at the three control points to obtain the arc curve. At the same time, use the Line component to draw a line at two points for the first and last control points of the three control points on the web plate of the channel steel part, and use the Curve Middle component to extract the midpoint of the curve, that is, extract the midpoint of the perpendicular line of the part. Then use the nearest point Curve Closest Point group to calculate the intersection of the perpendicular line and the arc curve, that is, the point on the corresponding arc curve of the part arch height.

[0106] (3) Using the Vector 2pt component that creates a vector from 2 points, a vector is constructed based on the midpoint of the perpendicular bisector and the intersection of the perpendicular bisector and the arc curve. Then, by controlling the movement of this vector, the intersection of the perpendicular bisector and the arc curve can be moved up or down. (4) Use the Move component to move the vector and calculate its position after moving 1mm in the forward direction. Replace the previous intermediate control point with this position and use the Arc 3pt component to draw an arc at 3 points. That is, draw an arc again at the three control points to obtain the arc radius. Similarly, use the multiplication component and the Move component to move in the reverse direction and calculate the position of the vector after moving 1mm in the reverse direction. Replace the previous intermediate control point with this position and use the Arc 3pt component to draw an arc at 3 points. That is, draw an arc again at the three control points to obtain the arc radius. (5) Use the Merge component to merge the list and merge the two arc radii obtained in step (4) into “bending radius fluctuation range”.

[0107] Step S32: Determine whether there is a unique common subset of the bending radius fluctuation range of all arc-shaped parts in the group. If there is, divide all arc-shaped parts in the group into a second-level group. If not, determine the number of second-level groups and the result of second-level groups based on the intersection of the bending radius fluctuation range of each arc-shaped part in the group.

[0108] Specifically, it can be understood that curved parts with the same or similar radii are grouped together. While ensuring processing error, it is necessary to determine whether there is an intersection between the allowable fluctuation range of the radius [R_min, R_max]. The common intersection of the radius intervals of all parts in the current group is found, or the minimum common intersection among the radius intervals of all parts in the current group is found, so as to achieve the bending processing of curved parts with the minimum bending radius.

[0109] Specifically, it can also be understood that when determining whether the bending radius fluctuation ranges of various curved parts overlap, it is necessary to first determine whether a unique common subset exists. If a unique common subset exists, that is, when there is an overlap between all bending radius fluctuation ranges, all parts in the current group can be bent using the same processing radius. If a unique common subset does not exist, then the number of groups and the grouping result need to be determined based on the overlap of the bending radius fluctuation ranges. The absence of a unique common subset could mean that there is no overlap between all bending radius fluctuation ranges, i.e., no pairwise overlap between any two bending radius fluctuation ranges, or that the overlapping portions of some bending radius fluctuation ranges are different from other bending radius fluctuation ranges or other overlapping portions. Therefore, when a unique common subset does not exist, grouping needs to be done based on the specific overlap situation.

[0110] In some embodiments, if there is no unique common subset, the number of groups and the grouping result are determined based on the intersection of the bending radius fluctuation ranges. That is, the number of second-level groups and the second-level grouping result are determined based on the intersection of the bending radius fluctuation ranges of each arc-shaped part within the group, including: Step a1: Calculate the number of the maximum non-overlapping intervals of all bending radius fluctuation ranges within a group as the number of groups for the second-level grouping.

[0111] The maximum number of non-intersecting intervals refers to the maximum number of intervals that are not intersecting in any pair, which is the maximum number of non-intersecting fluctuation ranges among all the ranges of curvature radius fluctuations.

[0112] Step a2: Sort all bending radius fluctuation ranges in the group from smallest to largest to obtain the sorted bending radius fluctuation range sequence.

[0113] Specifically, each bending radius fluctuation range is considered an interval. Sorting can be done directly according to the size of the interval endpoints. That is, sorting all bending radius fluctuation ranges within a group from smallest to largest is done by sorting the left endpoint of each fluctuation range from smallest to largest. When the left endpoints are the same, sorting is done by the size of the right endpoint. For example, each bending radius fluctuation range is [R_min, R_max], with the corresponding left endpoint being R_min and the right endpoint being R_max. Assuming there are N bending radius fluctuation ranges in the current group, sorting from smallest to largest is done by sorting the left endpoints from smallest to largest. This means sorting the R_min values ​​of the N bending radius fluctuation ranges from smallest to largest, and when R_min values ​​are the same, sorting is done by the right endpoint R_max from smallest to largest, ultimately resulting in [R1_min, R1_max], [R2_min, R2_max], ..., [RN_min, RN_max], where R1_min ≤ R2_min ≤ ... ≤ RN_min.

[0114] Step a3: Construct a second-level grouping for dividing the range of bending radius fluctuations based on the number of groups in the second-level grouping, and initialize each second-level grouping.

[0115] Specifically, the number of the maximum disjoint intervals is denoted as K, that is, the number of the second-level groups is K; each group uses a list to store the intervals and maintains a value max_l and a value min_r. max_l represents the maximum value of the left endpoints of all intervals in the group and the initial value of max_l is 0. min_r represents the minimum value of the right endpoints of all intervals in the group and the initial value of min_r is +∞. For example, the left endpoint of the first second-level group interval is K1.max_l=0 and the right endpoint is K1.min_r=∞, and the left endpoint of the second second-level group interval is K2.max_l=0 and the right endpoint is K2.min_r=∞.

[0116] Step a4: Based on the sorted sequence of bending radius fluctuation ranges, traverse each second-level group sequentially and update the second-level group when the merging condition is met, until all bending radius fluctuation ranges have been grouped into second-level groups.

[0117] Specifically, when the merging condition is met, it means that the left endpoint in the bending radius fluctuation range is less than the right endpoint of any second-level grouping interval; for [R1_min, R1_max], [R2_min, R2_max], ……, [RN_min, RN_max], each bending radius fluctuation range is used to traverse each second-level grouping in turn until the current second-level grouping does not meet the merging condition before traversing the next second-level grouping: Suppose when the first bending radius fluctuation range [R1_min, R1_max] traverses the first second-level grouping, first judge whether the left endpoint R1_min of the bending radius fluctuation range [R1_min, R1_max] is less than K1.min_r, the right endpoint of the first second-level grouping interval. Since R1_min < K1.min_r, the first bending radius fluctuation range sequence [R1_min, R1_max] is divided into the first second-level grouping. At the same time, the left endpoint K1.max_l of the first second-level grouping interval is updated according to the left endpoint R1_min of the bending radius fluctuation range, K1.max_l = max(K1.max_l, R1_min), and the right endpoint K1.min_r of the first second-level grouping interval is updated according to the right endpoint R1_max of the bending radius fluctuation range, K1.min_r = min(K1.min_r, R1_max) = R1_max; Then, when the second bending radius fluctuation range [R1_min, R1_max] traverses the first second-level group, it first checks whether the left endpoint R2_min of the bending radius fluctuation range [R2_min, R2_max] is less than the right endpoint K1.min_r of the first second-level group interval. If R2_min <= R1_max, then the second bending radius fluctuation range sequence [R2_min, R2_max] is also divided into the first second-level group. At the same time, based on the left endpoint R2_min of the bending radius fluctuation range, the left endpoint K1.max_l = max(K1.max_l, R2_min) of the first second-level group interval is updated, and based on the right endpoint R2_max of the bending radius fluctuation range, the right endpoint K1.min_r = min(K1.min_r, R2_max) of the first second-level group interval is updated. If R2_min > R1_max, then the first second-level group is completed, containing only one bending radius fluctuation range [R1_min, R1_max], and the second bending radius fluctuation range [R2_min, R2_max] is not included. R2_max] will traverse the second second-level group and assign it to the second second-level group. At the same time, it will update the left endpoint of the second second-level group interval K2.max_l=max(K2.max_l,R2_min) according to the left endpoint R2_min of the bending radius fluctuation range, and update the right endpoint K2.min_r = min(K2.min_r,R2_max)=R2_max according to the right endpoint R2_max of the bending radius fluctuation range. Finally, repeat the above steps for each range of bending radius fluctuation until all bending radius fluctuation ranges have completed the second-level grouping. For example, the first second-level group is {[R1_min, R1_max], [R2_min, R2_max]}, the second second-level group is {[R3_min, R3_max], [R4_min, R4_max], ..., [R10_min, R10_max]}, and the Kth second-level group is {[R50_min, R50_max], [RN_min, RN_max]}.

[0118] Step S33: Determine a common bending radius for each second-level group.

[0119] Specifically, if there is a unique common subset of the bending radius fluctuation range of each arc-shaped part in the group, then a bending radius is selected from the common subset as the processing radius of the current group. If there is no unique common subset, then a bending radius needs to be selected from the common subset of each second-level group as the processing radius of the current second-level group.

[0120] For example, after all bending radius fluctuation ranges have been grouped into second-level groups, the first second-level group is {[R1_min, R1_max], [R2_min, R2_max]}, the second second-level group is {[R3_min, R3_max], [R4_min, R4_max], ..., [R10_min, R10_max]}, and the Kth second-level group is {[R50_min, R50_max], [RN_min, RN_max]}. Then, the interval corresponding to each second-level group is the common subset of all bending radius fluctuation ranges within that second-level group. Taking the interval [K1.max_l, K1.min_r] of the first second-level group as an example, the bending radius fluctuation ranges [R1_min, R1_max] and [R2_min, R1_max] are... The intersection of [R2_max] is [K1.max_l, K1.min_r]. When determining the common bending radius, you can directly select it within the interval [K1.max_l, K1.min_r].

[0121] In some embodiments, when determining the common bending radius of each second-level group, if there are multiple bending radii in the common subset, they can be determined in conjunction with the standard mold radius of the workshop equipment. For example, the standard mold radius in the existing mold library of the workshop can be selected first. In this way, when processing the parts of this group, the existing mold can be directly called to achieve true "zero mold change" or "minimum mold change" preparation time, and the efficiency can be maximized. If there is only one bending radius in the common subset, the bending radius is taken as the common bending radius. In this case, if the common bending radius is a new radius, a new standard mold can be customized.

[0122] In the aforementioned method of dividing the second-level grouping, based on the geometric relationship between arch height, arc length, and bending radius, the product's quality requirement of "arch height machining error" is accurately converted into the allowable range of control parameters for the production process. That is, the allowable fluctuation range of the bending radius is deduced from the machining error, ensuring the feasibility and reliability of the final machining plan. Simultaneously, the second-level grouping of curved parts is achieved based on the allowable fluctuation range of the bending radius. Each group uses a common bending radius for machining, ensuring that all parts within the same second-level group can be machined using the same set of molds, significantly reducing the number of mold changes and improving machining efficiency. Furthermore, compared to the traditional "one material, one bend" method, this disclosure, by finding a common machining radius for each second-level group, allows multiple curved parts to be continuously bent and machined on a single long raw material, reducing clamping losses from "multiple" to "one," greatly improving raw material utilization.

[0123] Figure 8 This is a schematic diagram of the machining system for an arc-shaped part provided in this disclosure. See also... Figure 8 The system 800 includes: The model parsing unit 810 is used to obtain a three-dimensional model of the target machining plan, and to parse and extract parameter information of all parts from the three-dimensional model. The parameter information includes material information and geometric information. The feature grouping unit 820 is used to divide all parts into different categories of parts based on the material information according to the material specifications and grades, and to perform arc feature recognition on each category of parts based on the geometric information to obtain different categories of arc-shaped parts sets. Orientation grouping unit 830 is used to identify the opening orientation of each arc-shaped part and divide each arc-shaped part set into two first-level groups according to the different opening orientations. The opening orientations include: facing the center and facing away from the center, where the center is the center of the arc-shaped part. The radius grouping unit 840 is used to calculate the bending radius fluctuation range of each arc-shaped part in each first-level group based on the preset arch height processing error requirement, divide the arc-shaped parts with overlapping bending radius fluctuation ranges into the same second-level group, and determine a common bending radius for each second-level group. The processing planning unit 850 is used to generate a processing plan table for each second-level group based on the raw material length, clamping loss and the common bending radius. The processing plan table is used to guide the processing of multiple arc-shaped parts using the common bending radius on the same raw material.

[0124] For a detailed description of the above-described machining system for arc-shaped parts, please refer to the description of the relevant method steps in the above embodiments; repeated details will not be repeated. The embodiments of the machining method and system for arc-shaped parts described above are merely illustrative. The "units" and "modules" used as separate components can be combinations of software and / or hardware that implement a predetermined function, and may or may not be physically separate. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and not to limit them; although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure, and should all be covered within the protection scope of this invention.

Claims

1. A method for machining an arc-shaped part, characterized in that, The method includes: Obtain a three-dimensional model of the target machining plan, and parse and extract parameter information of all parts from the three-dimensional model. The parameter information includes material information and geometric information. Based on the material information, all parts are divided into different categories of parts according to material specifications and grades, and the arc feature is identified for each category of parts based on the geometric information to obtain different categories of arc-shaped parts. Identify the opening orientation of each arc-shaped part, and divide each set of arc-shaped parts into two first-level groups according to the different opening orientations. The opening orientations include: facing the center and facing away from the center, where the center is the center of the arc-shaped part. For each first-level group, the bending radius fluctuation range of each arc-shaped part in the group is calculated based on the preset arch height processing error requirement. Arc-shaped parts with overlapping bending radius fluctuation ranges are divided into the same second-level group, and a common bending radius is determined for each second-level group. For each second-level group, a processing plan is generated based on the raw material length, clamping loss, and the common bending radius. The processing plan is used to guide the processing of multiple arc-shaped parts using the common bending radius on the same raw material.

2. The processing method for arc-shaped parts as described in claim 1, characterized in that, The geometric information includes first geometric information or second geometric information; The parameter information of all parts is parsed and extracted from the 3D model, including: If the three-dimensional model is a building information model containing parametric attributes, it is connected to the application programming interface of the software that created the building information model to directly read the material information and first geometric information of each part. The first geometric information includes part length, control point position, number of control points, and part radius attribute. or, If the three-dimensional model is a geometric model without parametric attributes, then the material information and second geometric information of all parts are extracted by reading and parsing the geometric model. The second geometric information includes part length, control point position and control point number.

3. The processing method for arc-shaped parts as described in claim 2, characterized in that, The arc feature recognition includes: recognizing arc-shaped parts based on the number of control points and the radius attribute of the parts, or recognizing arc-shaped parts using a geometric fitting algorithm based on the number of control points and the position of the control points.

4. The processing method for arc-shaped parts as described in claim 1, characterized in that, The identification of the opening orientation of each arc-shaped component specifically includes: The bending radius of each arc-shaped part is determined based on its geometric information. Extract the centerline of each curved part and calculate the center bending radius corresponding to each centerline; The opening orientation of each arc-shaped part is determined based on the size of its bending radius and central bending radius. If the bending radius is greater than the central bending radius, the opening orientation is facing the center of the circle; if the bending radius is less than the central bending radius, the opening orientation is facing away from the center of the circle.

5. The method for processing arc-shaped parts as described in claim 1, characterized in that, For each first-level group, based on a preset arch height processing error requirement, the bending radius fluctuation range of each arc-shaped part within the group is calculated. Arc-shaped parts whose bending radius fluctuation ranges overlap are grouped into the same second-level group, and a common bending radius is determined for each second-level group, including: For each first-level group, the bending radius fluctuation range of each arc-shaped part in the group is calculated based on the preset arch height processing error requirements; Determine whether there is a unique common subset of the bending radius fluctuation range of all curved parts in the group. If there is, divide all curved parts in the group into a second-level group. If not, determine the number of second-level groups and the result of second-level grouping based on the intersection of the bending radius fluctuation range of each curved part in the group. A common bending radius is determined for each second-level group.

6. The method for processing arc-shaped parts as described in claim 5, characterized in that, For each first-level group, the bending radius fluctuation range of each arc-shaped part within the group is calculated based on a preset arch height processing error requirement, including: The arc length and bending radius of each arc part are extracted based on the geometric information of each arc part, and the actual arch height of each arc part is calculated based on the arc length and bending radius. The theoretical allowable range of arch height for each arc-shaped part is calculated based on the preset arch height machining error and the actual arch height. Based on the theoretical allowable range of arch height and the arc length, the range of bending radius fluctuation corresponding to the bending radius can be solved.

7. The method for processing arc-shaped parts as described in claim 5, characterized in that, The determination of the number of second-level groups and the result of the second-level grouping based on the intersection of the bending radius fluctuation ranges of each arc-shaped part within the group includes: The number of the largest non-overlapping intervals of all bending radius fluctuation ranges within a group is used as the number of groups for the second level of grouping; Sort all bending radius fluctuation ranges within a group from smallest to largest to obtain a sorted sequence of bending radius fluctuation ranges. Construct a second-level grouping system based on the number of groups in the second-level grouping system to divide the range of bending radius fluctuations, and initialize each second-level grouping system. Based on the sorted sequence of bending radius fluctuation ranges, each second-level group is traversed sequentially, and the second-level group is updated when the merging condition is met, until all bending radius fluctuation ranges are grouped into second-level groups.

8. The method for processing arc-shaped parts as described in claim 1, characterized in that, The material information includes material specifications and material grade; the types of raw materials include finished raw materials and sheet materials; and the fixed lengths of the raw materials include fixed lengths and customized lengths.

9. The method for processing arc-shaped parts as described in claim 8, characterized in that, The process of generating a nesting and processing plan table for each second-level group, based on the raw material length, clamping loss, and the common bending radius, includes: For each second-level group, the type and clamping loss of the target raw material are determined based on the material information of any arc-shaped part in the group, and the initial length of the target raw material is determined based on the processing capacity of the workshop equipment. Calculate the sum of the arc lengths of all curved parts within the group; The required quantity of target raw materials is determined based on the sum of the arc lengths and the clamping losses. The utilization rate of processing at least one arc-shaped part on each target raw material is calculated. A new processing plan is generated based on the allocation results of the arc-shaped parts when the utilization rates of all target raw materials meet the preset conditions.

10. A machining system for arc-shaped parts, characterized in that, The system includes: The model parsing unit is used to obtain a three-dimensional model of the target machining plan, and to parse and extract parameter information of all parts from the three-dimensional model. The parameter information includes material information and geometric information. The feature grouping unit is used to divide all parts into different categories of parts based on the material information according to the material specifications and grades, and to perform arc feature recognition on each category of parts based on the geometric information to obtain different categories of arc-shaped parts sets. Orientation grouping unit, used to identify the opening orientation of each arc-shaped part, and divide each arc-shaped part set into two first-level groups according to the different opening orientations, the opening orientations including: facing the center and facing away from the center, the center being the center of the arc-shaped part; The radius grouping unit is used to calculate the bending radius fluctuation range of each arc-shaped part in each first-level group based on the preset arch height processing error requirement, divide the arc-shaped parts with overlapping bending radius fluctuation ranges into the same second-level group, and determine a common bending radius for each second-level group. The processing planning unit is used to generate a processing plan table for each second-level group based on the raw material length, clamping loss and the common bending radius. The processing plan table is used to guide the processing of multiple arc-shaped parts using the common bending radius on the same raw material.

Images