A method and system for machining an arc-shaped part

Abstract

The disclosure provides a processing method and system of arc-shaped parts, the method comprising: extracting parameter information of all parts, dividing the parts into different part sets according to material specifications and grades, and identifying arc-shaped features based on geometric information to obtain different sets of arc-shaped parts; identifying the opening orientation of each arc-shaped part, and dividing each set of arc-shaped parts into two first-level groups according to the opening orientation; calculating the bending radius fluctuation range of each arc-shaped part in the group based on the preset arch height machining error requirement, dividing the arc-shaped parts with the intersection of the bending radius fluctuation range into the same second-level group, and determining the common bending radius; and generating a processing schedule according to the raw material length, clamping loss and the common bending radius. The disclosure realizes the full-process automation of identifying arc-shaped parts from a three-dimensional model, determining the opening orientation, and generating a grouped processing schedule, significantly improving the raw material utilization rate and processing efficiency.

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 very low. The machining of arc-shaped parts needs to go through multiple processes such as bending forming and cutting. Due to the special parameters of the arc-shaped profile that need to be adapted 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:

[0004] First, the efficiency of obtaining 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.

[0005] 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 due to the inability to 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.

[0006] In summary, the technical defects of the existing arc-shaped part machining process in the aspects of machining parameter acquisition and raw material utilization have been difficult to meet the current manufacturing field's demand for efficient and low-cost processing, and an arc-shaped part machining method capable of realizing automatic identification of machining parameters and optimized combination of machining tasks is urgently needed to solve the above technical problems. SUMMARY

[0007] The present application provides an arc-shaped part machining method and system to solve the problems of low efficiency and high error rate in acquiring machining parameters, low raw material utilization rate, and poor flexibility of machining plans in the prior art.

[0008] In a first aspect, the present disclosure provides an arc-shaped part machining method, which comprises:

[0009] acquiring a three-dimensional model of a target machining plan, analyzing and extracting parameter information of all parts from the three-dimensional model, the parameter information including material information and geometric information;

[0010] dividing all parts into different categories of part sets based on the material information and performing arc feature recognition on each category of part set based on the geometric information to obtain different categories of arc-shaped part sets;

[0011] identifying the opening orientation of each arc-shaped part and dividing each arc-shaped part set into two first-level groups according to the difference in opening orientation, the opening orientation including: facing the center direction and facing away from the center direction, the center being the center of the arc-shaped part;

[0012] 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 machining error requirement, divide the arc-shaped parts with intersecting bending radius fluctuation ranges into the same second-level group, and determine a common bending radius for each second-level group;

[0013] For each second-level group, generate a machining plan table according to the raw material length, clamping loss, and common bending radius, the machining plan table being used to guide the machining of multiple arc-shaped parts using the common bending radius on the same raw material.

[0014] According to the arc-shaped part processing method provided by the present disclosure, the geometric information includes first geometric information or second geometric information; the parameter information of all parts is parsed 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, extracting the material information and the second geometric information of all parts by reading and parsing the geometric model, the second geometric information including part length, control point position and control point number.

[0015] According to the arc-shaped part processing method provided by the present disclosure, the arc-shaped feature recognition includes: recognizing the arc-shaped part based on the control point number and the part radius attribute, or recognizing the arc-shaped part based on the control point number and the control point position by using a geometric fitting algorithm.

[0016] According to the arc-shaped part processing method provided by the present disclosure, the opening direction includes: directly facing the center direction and facing away from the center direction; the opening direction of each arc-shaped part is recognized, specifically including: determining the bending radius of each arc-shaped part according to 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 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 directly facing the center direction, and if the bending radius is less than the center bending radius, the opening direction is facing away from the center direction.

[0017] According to the arc-shaped part processing method provided by the present disclosure, 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 machining error requirement, the arc-shaped parts with the intersection of the bending radius fluctuation range are divided 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 machining error requirement; it is judged whether the bending radius fluctuation range of all arc-shaped parts in the group has a unique common subset, if there is, all arc-shaped parts in the group are divided into a second-level group, if there is not, the number and result of the second-level group are determined according to the intersection of the bending radius fluctuation range of each arc-shaped part in the group; a common bending radius is determined for each second-level group.

[0018] According to the method for processing the arc-shaped parts provided in the present disclosure, the bending radius fluctuation range of each arc-shaped part in the group is calculated based on the preset arch height machining error requirement, which comprises: the arc length and the bending radius of each arc-shaped part are extracted according to the geometric information of each arc-shaped part, and the actual arch height of each arc-shaped part is calculated according to the arc length and the bending radius; the theoretical arch height allowable range of each arc-shaped part is calculated according to the preset arch height machining error and the actual arch height; and the bending radius fluctuation range corresponding to the bending radius is inversely solved according to the theoretical arch height allowable range and the arc length.

[0019] According to the method for processing the arc-shaped parts provided in the present disclosure, the number of the second-level groupings and the second-level grouping results are determined according to the intersection condition of the bending radius fluctuation range of each arc-shaped part in the group, which comprises: the maximum number of disjoint intervals of all the bending radius fluctuation ranges in the group is calculated as the number of the second-level groupings; all the bending radius fluctuation ranges in the group are sorted from small to large to obtain a sequence of the sorted bending radius fluctuation ranges; the second-level groupings for dividing the bending radius fluctuation ranges are constructed according to the number of the second-level groupings, and each second-level grouping is initialized; and each second-level grouping is sequentially traversed based on the sequence of the sorted bending radius fluctuation ranges, and the second-level grouping is updated when the merging condition is met, until all the bending radius fluctuation ranges are completed for the second-level grouping.

[0020] According to the method for processing the arc-shaped parts provided in the present disclosure, the material information comprises the material specification and the material grade; the types of the raw materials comprise the finished product raw material and the plate raw material, and the fixed length and the customized length are included in the fixed length of the raw material.

[0021] According to the method for processing the arc-shaped parts provided in the present disclosure, the material information comprises the material specification and the material grade; the types of the raw materials comprise the finished product raw material and the plate raw material, and the fixed length and the customized length are included in the fixed length of the raw material.

[0022] In the second aspect, the present disclosure further provides a processing system for arc-shaped parts, which comprises:

[0023] A model analysis unit is configured to obtain a three-dimensional model of a target processing plan, and analyze and extract parameter information of all parts from the three-dimensional model, wherein the parameter information comprises material information and geometric information.

[0024] a feature grouping unit configured to divide all the parts into different sets of parts according to material specifications and grades based on the material information, and to perform arc feature recognition on each set of parts according to the geometric information, to obtain different sets of arc-shaped parts;

[0025] a direction grouping unit configured to identify the opening direction of each arc-shaped part, and divide each set of arc-shaped parts into two first-level groups according to different opening directions, the opening direction including a direction facing the center and a direction away from the center, the center being the center of the arc-shaped part;

[0026] a radius grouping unit configured to, for each first-level group, calculate the bending radius fluctuation range of each arc-shaped part in the group based on a preset camber machining error requirement, divide the arc-shaped parts with intersecting bending radius fluctuation ranges into the same second-level group, and determine a common bending radius for each second-level group;

[0027] a machining planning unit configured to, for each second-level group, generate a machining schedule according to the raw material length, clamping loss and the common bending radius, the machining schedule being used to guide the machining of multiple arc-shaped parts using the common bending radius on the same raw material.

[0028] In summary, the machining method and system for arc-shaped parts provided by the present disclosure deeply integrate three-dimensional models, geometric algorithms and optimized nesting strategies, forming a highly intelligent and refined machining preparation method and system for arc-shaped parts. The method and system can quickly and accurately divide multiple arc-shaped parts of different specifications, grades, directions and bending radii into multiple groups that can be combined for machining, providing a powerful technical tool for the digital transformation and cost reduction and efficiency improvement of the building steel structure industry.

[0029] The machining method for arc-shaped parts provided by the present disclosure first automatically analyzes, extracts and filters arc-shaped parts corresponding to various types and grades of profiled steel from three-dimensional models corresponding to machining plans, and quickly obtains information such as arc length and bending radius of the arc-shaped parts by analyzing the geometric characteristics of each arc-shaped part. Then, the opening direction of the arc-shaped part is automatically determined based on the size of the bending radius between different control points on the arc-shaped part. By converting the machining requirement of each part from an absolute bending radius value to a flexible radius interval, the machining grouping of the arc-shaped part is quickly realized. Finally, after first-level grouping and second-level grouping of the arc-shaped parts according to the opening direction and the bending radius fluctuation range, the nesting method in each second-level group is optimized, with the goal of minimizing the number of raw materials and maximizing the utilization rate of single raw material, to generate an optimal machining schedule, greatly improving the utilization rate of raw materials and machining efficiency, and fully considering the complexity of actual workshops, with good adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the present disclosure or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0031] Figure 1 is a flowchart of a processing method of an arc-shaped part provided by the present disclosure;

[0032] Figure 2 is a schematic diagram of a section of a typical open section steel part provided by the present disclosure;

[0033] Figure 3a 、 Figure 3b and Figure 3c is a complete operator group schematic diagram of arc-shaped feature recognition provided by the present disclosure;

[0034] Figure 4a is a flowchart of a method for identifying the opening direction of each arc-shaped part provided by the present disclosure;

[0035] Figure 4b is a schematic diagram of an arc-shaped part provided by the present disclosure;

[0036] Figure 4c is a schematic diagram of another arc-shaped part provided by the present disclosure;

[0037] Figure 5 is a complete operator group schematic diagram of identifying the opening direction of each arc-shaped part provided by the present disclosure;

[0038] Figure 6 is a flowchart of a method for dividing a second-level group provided by the present disclosure;

[0039] Figure 7 is a complete operator group schematic diagram of calculating the fluctuation range of the bending radius provided by the present disclosure;

[0040] Figure 8 is a structural schematic diagram of a processing system of an arc-shaped part provided by the present disclosure. DETAILED DESCRIPTION

[0041] In order to make the purposes, technical solutions and advantages of the present disclosure clearer, the technical solutions in the present disclosure will be described clearly and completely below in conjunction with the drawings in the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present disclosure.

[0042] Grasshopper (abbreviated as GH) is a visual programming language based on the Rhino three-dimensional modeling platform, and has cross-field technical characteristics: on the one hand, its core function focuses on data-based design, and can realize direct conversion from design logic to visual results; on the other hand, its technical boundary overlaps with the field of interaction design, and can meet the interaction needs of people and systems in the design process, solve the technical pain points of “disconnection between design logic and interaction feedback” in traditional design, and is a key tool in the current data-based design field that has the dual advantages of “visual programming” and “cross-field adaptation”.

[0043] GH is not only suitable for data-based design scenarios, but also can be extended and applied to the steel processing link in the workshop, and the processing method of the arc-shaped part provided in the present disclosure is to realize automatic extraction of parameter information of the part based on the three-dimensional model, automatic screening of arc-shaped parts corresponding to different types and different grades of profile steel based on the parameter information, automatic identification of the opening direction of the arc-shaped part and grouping, automatic calculation of the bending of the arc-shaped part and grouping according to the bending radius, and output of the optimal processing plan table of the nesting, etc., to avoid errors in the manual conversion link, reduce the number of die changes, improve the utilization rate of raw materials, and thus improve the processing efficiency and precision of the part.

[0044] Figure 1 is a flowchart of a processing method of an arc-shaped part provided in the present disclosure, and the method is realized based on Grasshopper, that is, a related battery pack is constructed according to the arc-shaped part processing method provided in the present disclosure by using the Grasshopper plug-in to realize the processing of the arc-shaped part.

[0045] Referring to Figure 1 , the method comprises:

[0046] In step S11, a three-dimensional model of a target processing plan is acquired, and parameter information of all parts is parsed and extracted from the three-dimensional model, and the parameter information comprises material information and geometric information.

[0047] The target processing plan refers to a production task designed for a certain production task, such as a data set of all parts required for a building project or a product assembly. The three-dimensional model of the target processing plan can be a three-dimensional digital model containing rich parameterized information such as the geometry of each part, material information, and spatial relationship, or a non-parameterized pure geometric three-dimensional digital model.

[0048] The material information refers to the relevant information of the corresponding material of each part, including material specification and material grade. The material specification represents the type of steel and the cross-sectional specification of the part, and the type of steel refers to various open steel produced by cold bending forming process, including channel steel, angle steel, T-shaped steel, Z-shaped steel, H-shaped steel, I-shaped steel, etc., and the corresponding cross-sectional shape includes C-shaped, L-shaped, T-shaped, Z-shaped, H-shaped, I-shaped, etc.

[0049] Figure 2 is a schematic diagram of the cross section of a typical open steel part provided by the present disclosure. Referring to Figure 2 The four cross-sectional shapes shown in are C-shaped cross section of channel steel, L-shaped cross section of angle steel, Z-shaped cross section of Z-shaped steel, and T-shaped cross section of T-shaped steel.

[0050] Further, according to the material specification, the cross-sectional shape, size, weight, technical requirements, etc. of various types of steel can be determined, such as material specification C12, which represents channel steel with C-shaped cross section and cross-sectional height of 120mm. The material grade represents the steel grade of the part, which is generally Q235B grade steel.

[0051] The geometric information refers to the shape, length, and other geometric information of the part when it is drawn, such as the position, number, and radius attribute of the control points used when drawing a part, or the position and number of multiple control points when drawing a part, or the number and position of control points and the length of the part obtained by analyzing a drawn part.

[0052] Specifically, it can be understood that due to the difference in software used in the design, process planning, and processing and manufacturing stages, data cannot flow seamlessly between different stages. The three-dimensional model designed by the designer according to the actual operation requirements usually contains rich parameterized information, and the various software tools for processing the processing plan or three-dimensional model generally only have basic model processing functions, which are difficult to be directly and losslessly used by downstream processing software. In the processing stage, manual interpretation and manual input of tables are often required to count part information, which is low in efficiency and prone to human error. Therefore, a method is needed to automatically analyze and extract part parameter information from a three-dimensional model.

[0053] Specifically, it can also be understood that since the processing plan is provided by the customer, and different customers use different software to design the construction model of the processing plan, although the source model of the construction may be a three-dimensional model containing rich parameter information, sometimes even because of the requirements of design cost, data security, software compatibility, etc., the customer can only provide a non-parametric pure geometric model, at this time, it is necessary to perform geometric analysis on the pure geometric three-dimensional model to obtain the parameter information of the part. Therefore, different methods need to be used to extract the parameter information of the part for the three-dimensional model containing rich parameter information and the pure geometric three-dimensional model.

[0054] In some embodiments, if the customer provides a building information model containing parameterized attributes, that is, a three-dimensional model containing rich parameter information, the Grasshopper plug-in 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 used to establish the building information model, so that when the target software displays the current building information model, all relevant parameters of the parts contained in the model can be directly read from the target software, including but not limited to material information of each part and geometric information such as part position, part length, control point position, control point number, part radius attribute, etc. when designing each part.

[0055] In other embodiments, if the customer provides a geometric model that does not contain parameterized attributes, that is, a non-parametric pure geometric three-dimensional model, the geometric model needs to be obtained first, and the material information and the second geometric information of all parts are extracted by reading and analyzing the geometric model, such as reading and displaying the geometric model on the Rhino platform, then analyzing the geometric model, determining the material specification of each part by cross-sectional geometric analysis, identifying the additional identification information in the geometric model to determine the material grade, and determining the size information of each part by geometric calculation.

[0056] The cross-sectional geometric analysis of each part to determine the material specification includes: cutting in the length direction of the part to obtain a cross-sectional profile, matching the cross-sectional profile with the profiles in the standard steel database, if the matching is successful, the material specification is determined to be a specific specification model in the national standard steel, if the matching is unsuccessful, the material specification is determined to be non-national standard, which can be customized according to the cross-sectional shape and size. The additional identification information includes but is not limited to: color, layer or label text used to represent different steel grades of the part, at this time, identifying the additional identification information in the geometric model to determine the corresponding steel grade refers to determining the corresponding steel grade through the additional identification information of the part in the three-dimensional model. The size information of each part is determined by geometric calculation, including: taking the distance between the endpoints of the straight line or arc line on the outer boundary line of the part as the part length, and taking the radius of the arc fitting after fitting the multiple control points uniformly distributed on the part as the bending radius.

[0057] Further, the geometric information includes first geometric information or second geometric information; the parameter information of all parts is parsed and extracted from the three-dimensional model, including:

[0058] Step 111, if the three-dimensional model is a building information model containing parameterized attributes, then connect with the application programming interface of the software for establishing the building information model, directly read the material information and the first geometric information of each part, the first geometric information includes part length, control point position, control point number, part radius attribute; or,

[0059] Step 112, if the three-dimensional model is a geometric model without parameterized attributes, then extract the material information and the second geometric information of all parts by reading and parsing the geometric model, the second geometric information includes part length, control point position and control point number.

[0060] In step 111, the material information and the first geometric information of each part are directly read, that is, the material specification, material grade and the number, position and radius attribute of the control points used when drawing each part are directly read, for example, drawing an arc can be drawn by two control points and a non-zero radius, or three control points can be used to draw a circular arc, and the part length in the first geometric information refers to the length of the part, such as the arc length of the arc-shaped channel steel part, the bending radius, the arc length is the length of the longest arc-shaped edge on the geometric profile of the arc-shaped channel steel part, and the bending radius can be the distance from the center to the flange tip or the distance from the center to the web, which is uniformly defined as the distance from the center to the vertical plate in the disclosure, such as the bending radius of the channel steel part being the distance from the center to the web, the bending radius of the T-shaped steel part being the distance from the center to the flange, the bending radius of the angle steel part being the distance from the center to the vertical flange, etc.

[0061] In step 112, the material information and the second geometric information of all parts are extracted, that is, according to the displayed geometric model, three points are uniformly selected as control points in the length direction of the part, and the cross section profile is obtained by cutting on the three control points, the material specification of the current part is determined according to the cross section shape, and the type of the current part is determined according to the cross section size.

[0062] It should be noted that in step 112, three points are generally selected in the length direction of the part, one point is selected at the first end, the tail end and the middle of the control line on the back of the part, and the middle position point is analyzed as a cross section, and the three points do not need to be analyzed as a cross section, and the control point of the first end can be selected at the end surface of the first end of the part, and the control point of the tail end can be selected at the end surface of the tail end of the part.

[0063] Step S12, based on the material information, all parts are divided into different categories of part sets according to the material specification and grade, and arc feature recognition is performed on each category of part set based on the geometric information, to obtain different categories of arc part sets.

[0064] Specifically, it can be understood that the existing software for processing machining plans or three-dimensional models lacks special tools for automatic identification and feature extraction of arc-shaped parts, so the present disclosure proposes a method for grouping parts by type and grade of section steel and recognizing arc features. Classifying all parts can be reading material specification information, first determining the type of section steel according to the first letter of the material specification information, then determining the cross-sectional size according to the material specification information, and determining the steel grade corresponding to the part according to the material grade information. If only a certain type of section steel part needs to be processed accurately in the actual project, there is no need to classify all parts, and the target type part can be directly filtered according to the first letter of the material specification information. If the target type part is a channel steel part, the part with the first letter C is filtered; if the target type part is an angle steel part, the part with the first letter L is filtered; if the target type part is a T-shaped steel part, the part with the first letter T is filtered; if the target type part is a Z-shaped steel part, the part with the first letter Z is filtered. Arc feature recognition, since the drawing of an arc line requires two control points plus a bending radius or more than three control points to realize a circular arc, the control point condition of the part can be analyzed, for example, whether the radius attribute of the control point is zero or null, and whether the number of control points is equal to two or greater than two, to determine whether it is an arc-shaped part.

[0065] Further, the based on the material information, all parts are divided into different categories of part sets according to the material specification and grade, and arc feature recognition is performed on each category of part set based on the geometric information, to obtain different categories of arc part sets, including:

[0066] Step S121, based on the material information, all parts are divided into different categories of part sets according to the material specification and grade.

[0067] In order to classify the same type of parts into the same group, the classification of the parts according to the material specification and grade is required, that is, all the parts are classified according to the material specification and grade based on the material information, including: reading the material specification information in the material information, and identifying the first letter of the material specification information; screening the parts of various steel types according to the first letter of the material specification information; reading the material grade information in the material information, and determining the parts of different grades for each type of steel part according to the material grade. For example, there are multiple parts of Q235B grade and multiple parts of Q355B grade in all parts with C12 material specification information, and the multiple parts with C12 material specification information and Q235B grade are classified into one category, and the multiple parts with C12 material specification information and Q355B grade are classified into one category.

[0068] In step S122, arc feature recognition is performed on each category of part set based on the geometric information to obtain different categories of arc part sets.

[0069] Because the geometric information is different, the geometric information and judgment method used in the arc feature recognition are also different, and because the bending angle of some arc parts is small, it can be almost equivalent to a straight part, at this time, the straight part can be used instead of this type of arc part, so when identifying the arc part, the bending degree of the part needs to be further judged according to the arch height, such as classifying the arc part with arch height satisfying the curve-to-straight condition as a straight part, wherein the curve-to-straight condition includes that the arch height of the part is less than or equal to the arch height threshold, and the arch height threshold is generally 1mm.

[0070] Specifically, the arc feature recognition includes: identifying the arc part based on the number of control points and the part radius attribute, or identifying the arc part based on the number of control points and the position of the control points using a geometric fitting algorithm. The arc feature recognition based on the geometric information includes: if the geometric information is first geometric information, identifying the arc part based on the number of control points and the part radius attribute; if the geometric information is second geometric information, identifying the arc part based on the number of control points and the position of the control points using a geometric fitting algorithm.

[0071] When the geometry information is the first geometry information, the geometry information includes a radius attribute, at this time, for a part with a control point number of two and a non-zero radius attribute, the arch height of the part needs to be further calculated, the part with an arch height greater than an arch height threshold is identified as an arc-shaped part, and for a part with a control point number greater than two, a null radius attribute, and any three control points can be circular arc, a geometric fitting algorithm is used to calculate the fitting circular arc radius and arch height of the any three control points that can be circular arc, and the part with a non-zero fitting circular arc radius and an arch height greater than the arch height threshold is identified as an arc-shaped part.

[0072] When the geometry information is the second geometry information, the geometry information does not include a radius attribute, then at least three control points need to be selected in the length direction of any part, and a circular arc is fitted for the at least three control points, and the fitting circular arc radius and arch height are calculated, and the part with a non-zero fitting circular arc radius and an arch height greater than the arch height threshold is identified as an arc-shaped part.

[0073] It should be noted that the arc-shaped part of the present disclosure refers to a circular arc-shaped part with a single bending radius, which is because in actual processing tasks, each part generally has a single bending radius circular arc, and there is no situation that a part has multiple different bending radii and can be bent into a wavy line. If there are indeed multiple different bending radii on a part in other actual engineering, the part with different bending radii can be cut off first, and each part after cutting is processed according to the arc-shaped part processing method provided by the present disclosure to obtain multiple separate arc-shaped parts, and finally the parts with different bending radii are spliced according to the drawing to obtain the parts with different bending radii.

[0074] Figure 3a 、 Figure 3b and Figure 3c is a complete operator group diagram of the arc-shaped feature recognition provided by the present disclosure, wherein Figure 3a is a control number part of identifying a part, Figure 3b is an arc-shaped feature part of identifying a part, Figure 3c is a part with an arch height greater than 1 mm is combined into an arc-shaped part part; taking a channel steel part as an example, when the "arc-shaped feature recognition is performed on each category of part set" method of step S122 is implemented based on Grasshopper, the layout of each part operator can be specifically referred to Figure 3a 、 Figure 3b and Figure 3c , that is, the complete operator of arc-shaped feature recognition includes:

[0075] (1) selecting an object, the object can be a target part in a three-dimensional model, such as a channel steel part;

[0076] (2) Decompose the object attribute using the Deconstruct Beam component, i.e. decompose the profile of the channel steel part; decompose the curve and extract the control points using the Explode Curve component, i.e. the vertices of the channel steel part web limb back position control line; store the control points in a list using the List Length component and calculate the list length, i.e. count the number of control points of the web control line; then use the Larger Than component to compare the size, i.e. compare the first number "the number of control points of the web" and the second number "2", and use the number judgment result as the split mode for subsequent list splitting;

[0077] (3) Use the Dispatch component to divide the target part into "parts with three or more control points" and "parts with two control points" according to the control point number judgment result in the split mode.

[0078] (4) For the object "parts with three or more control points", use the Deconstruct Beam component to decompose the object attribute; use the Explode Curve component to decompose the curve and extract the control points; use the List Item component to extract the objects in the list from the list storing the control points, i.e. the three control points of the channel steel part web limb back control line; use the Arc 3pt component to draw a circular arc with three points, i.e. draw a circular arc with three control points to get a circular arc curve, and for the channel steel part web, use the Line component to draw a line with two points, and the Curve Middle component to extract the midpoint of the curve, i.e. extract the midpoint on the vertical line of the part, and then use the Curve Closest Point component to calculate the distance from the midpoint of the curve to the circular arc, i.e. the rise of the part; then use the Larger Than component to compare the size, i.e. compare the first number "rise" with the second number "rise threshold value 1mm", and finally use the Dispatch component to divide the list storing "parts with three or more control points" into list A "parts with three-point circular arc rise greater than 1mm" and list B "parts with three-point circular arc rise less than or equal to 1mm";

[0079] (5) For the object "two control points of the part", first judge whether the radius attribute of the part is 0, and then judge whether the arch height is greater than 1 mm, that is, the radius attribute RADIUS of the object is obtained by using the Object Get Part Attribute component, the part radius is output by using the cMode component, the Equality component is used to judge whether the first number "radius attribute" is equal to the second number "0", and then the Dispatch component is used to split the list of the part storing two control points into the list "two control points and the radius attribute of the part is 0" and the list "two control points and the radius attribute of the part is not 0"; at the same time, the arc length attribute of the object is obtained by using the Object Get Part Attribute component, the judgment result of the Equality component on the radius attribute is used as the splitting mode, and the two Dispatch components are used to split the list "the radius of the part of two control points and the radius attribute is not 0" and the list "the arc length of the part of two control points and the radius attribute is not 0", and then the Eval component combined with the formula The arch height of the part is calculated, and then the Larger component is used to compare the judgment result of the first number "arch height" and the second number "arch height threshold 1 mm", and finally the Dispatch component is used to further subdivide the list "the part of two control points and the radius attribute is not 0" into the list A "the part of the arch height greater than 1 mm" and the list B "the part of the arch height less than or equal to 1 mm".

[0080] (6) The Merge component is used to merge the list "the part of the three-point arc and the arch height greater than 1 mm" in step (4) and the list "the part of two control points and the radius attribute is not 0" in step (5) to output the arc-shaped part.

[0081] In step S13, the opening direction of each arc-shaped part is identified, and each arc-shaped part set is divided into two first-level groups according to the different opening directions, and the opening directions include: facing the center direction and facing away from the center direction, and the center is the center of the arc-shaped part.

[0082] Specifically, it can be understood that each arc-shaped part set corresponds to a category of arc-shaped parts, such as a set of arc-shaped parts with a section specification of C12 and a grade of Q325B. Since the opening directions of all arc-shaped parts in each arc-shaped part set also differ, for axisymmetric arc-shaped parts, as long as they belong to the same category, whether their opening directions are the same or different, they can be further grouped according to the bending radius of the parts. For non-axisymmetric arc-shaped parts, arc-shaped parts with the same opening direction can be considered as a group, but arc-shaped parts with different opening directions need to be grouped according to the opening direction first. Therefore, for axisymmetric arc-shaped parts, there is no need to perform the first-level grouping according to the opening direction, and step S13 can be skipped to directly perform step S14 to perform the second-level grouping according to the bending radius. For non-axisymmetric arc-shaped parts, the opening direction of each arc-shaped part needs to be identified and then grouped according to the opening direction for the second level.

[0083] Among them, the axisymmetric arc-shaped part refers to the part with the cross-sectional shape satisfying the property of axisymmetry, such as an I-beam. The non-axisymmetric arc-shaped part refers to the part with the cross-sectional shape not satisfying the property of axisymmetry, such as a channel steel, an angle steel, a T-beam, a Z-shaped steel, etc.

[0084] The opening direction includes a direction facing the center and a direction away from the center, wherein the center refers to the center of the arc-shaped part, that is, the center corresponding to the arc of the arc-shaped part fitted and determined. The opening direction of the channel steel refers to whether the opening of the C-type faces the center or away from the center. The opening direction of the angle steel refers to whether the right angle opening of the L faces the center or away from the center. The opening direction of the T-beam refers to whether the web faces the center or away from the center. The opening direction 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 away from the center, or to determine whether the lower flange faces the center or away from the center.

[0085] In some embodiments, before step S13, the method further comprises: determining whether each arc-shaped part set is an axisymmetric arc-shaped part set according to the category information of each arc-shaped part set. If it is an axisymmetric arc-shaped part set, step S13 is skipped and step S14 is directly performed. If it is not an axisymmetric arc-shaped part set, step S13 is performed.

[0086] In other embodiments, the opening direction further includes a lying bending direction, the direction facing the center and the direction away from the center belong to the standing bending direction, and the lying bending direction is perpendicular to the standing bending direction. The lying bending is generally used to create the arc effect of the building facade, the arc eaves, the ceiling modeling, etc., and the standing bending is mainly used as the arc beam / arc main structure / large equipment framework / support / arc railing / handrail. When the part is bent in the lying bending, the opening of the part is perpendicular to the arc of the arc-shaped part and the plane where the center is located. The direction can be vertically upward or vertically downward. Taking a channel steel as an example, the lying bending refers to the bending of the channel steel part with its flange as the support, and the standing bending refers to the bending of the channel steel part with its web as the support. Since the opening direction is vertically upward or vertically downward when the bending radius is the same, the arc-shaped part with the opening direction vertically downward can be obtained by pulling bending vertically upward and then turning it over by 180 degrees. That is, the opening direction vertically upward and the opening direction vertically downward are the same in the pulling bending process and can be combined for processing. However, when the part is bent in the standing bending, the opening direction facing the center and the opening direction away from the center are not symmetrical and cannot be combined for processing. Therefore, the part bent in the lying bending can be directly divided into a group without further subdividing the specific opening direction grouping. Therefore, the opening direction is generally divided into the first direction facing the center, the second direction away from the center, and the third lying bending direction. At this time, step S13 can be to identify the opening direction of each arc-shaped part and divide each arc-shaped part set into three first-level groups according to the different opening directions, i.e., the direction facing the center, the direction away from the center, and the lying bending direction.

[0087] Further, taking a channel steel as an example, after obtaining the parameter information of the part through step 1, it is determined whether the arc is bent in the lying bending or the standing bending according to the web. If the arc is bent in the lying bending, it is determined that the opening direction belongs to the third direction. Otherwise, the arc is bent in the standing bending, and the opening direction belongs to the first or second direction, which needs to be further determined. The determination of whether the arc is bent in the lying bending or the standing bending according to the web specifically includes: determining whether the arc is bent in the lying bending or the standing bending according to the position relationship between the web and the arc surface of the part. If the web is perpendicular to the arc surface, the arc is bent in the standing bending. Otherwise, the arc is bent in the lying bending. The arc surface of the part refers to the plane where the arc of the arc-shaped part and the center are located. For example, if the radii of two points on the web at the positions of the flanges are different, it indicates that the arc is bent in the lying bending, and the opening direction belongs to the third direction. If the radii of the two points at the positions of the flanges are the same, it indicates that the arc is bent in the standing bending, and the opening direction belongs to the first or second direction, which needs to be further determined. For other types of channel steels, if the lying bending also exists in actual engineering applications, the lying bending and the standing bending also need to be determined first, such as a T-shaped steel. The position relationship between the flange of the T-shaped steel and the arc surface of the part is determined. The reference surface for determining the lying bending or the standing bending of different types of parts is different, which is not limited in the present disclosure.

[0088] Specifically, it can also be understood that the opening direction of each part is determined by judging the bending radius of each part and the size of the bending radius corresponding to the center line. Taking the channel steel part as an example, the bending radius is defined as the distance from the center to the vertical plate of the part, that is, the bending radius of the channel steel part is the distance from the center to the web plate. The determination of the center line of the part can be the line formed by the center points of multiple cross sections, such as the center line of the channel steel, which is the line where the center points of the rectangular cross section C are located. Then, the opening direction is determined by judging the bending radius and the size of the bending radius at the center line.

[0089] 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 machining error requirement, divide the arc-shaped parts with intersection of the bending radius fluctuation range into the same second-level group, and determine a common bending radius for each second-level group.

[0090] Specifically, it can be understood that in the process of cold bending type machining for bending a linear part into an arc-shaped part, different bending radius molds need to be replaced to obtain arc-shaped parts with different bending radii. Frequent mold replacement is a time-consuming and labor-intensive physical operation that can seriously disrupt the continuous machining process and become the efficiency bottleneck of the entire production process. In addition, each bending process can cause raw material waste due to clamping the part. Therefore, in order to reduce the number of mold replacements, reduce costs, and achieve high utilization in the processing of arc-shaped parts, the present disclosure proposes a method for grouping arc-shaped parts, so that each group of arc-shaped parts is processed with a common bending radius.

[0091] 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 machining error requirement; determining whether there is a unique common subset of the bending radius fluctuation range of all arc-shaped parts in the group, if there is, then dividing all arc-shaped parts in the group into a second-level group, if there is not, then determining the number of second-level groups and the second-level group result according to the intersection of the bending radius fluctuation range of each arc-shaped part in the group; determining a common bending radius for each second-level group.

[0092] Step S15, 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 is used to guide the processing of multiple arc-shaped parts with a common bending radius on the same raw material.

[0093] Specifically, it can be understood that for each category of parts, according to the opening direction and bending radius of the arc-shaped parts, arc-shaped parts with the same opening direction and the same common bending radius are divided into a second-level group, which makes each second-level group can process all arc-shaped parts in the group with the same bending radius, but in actual processing, since the size of the raw material used for processing the parts is also different, when the arc-shaped parts of each second-level group are combined for processing, the demand amount of raw materials and the utilization rate of raw materials also need to be calculated to ensure the highest utilization rate of raw materials when each second-level group is combined for processing.

[0094] The raw material refers to the raw material for processing the parts, and the types of the raw material include finished product raw material and plate raw material. The finished product raw material refers to a straight finished product, such as a finished channel steel, a finished angle steel or a finished T-shaped steel, etc., and the corresponding arc-shaped parts are directly obtained by stretch bending processing of the straight finished product. The plate raw material refers to a pure steel plate, which is used to customize special specification parts. The pure steel plate generally needs to be bent or welded to obtain customized parts. When the pure steel plate is used as the raw material, the plate can be directly bent to obtain the target type of straight steel, and then the straight steel is stretch bent to obtain the arc-shaped parts. Or the plate can be cut to obtain the web, flange, etc. of each part, and then the straight parts are welded and stretch bent to obtain the arc-shaped parts. Or the flange can be directly cut into an arc-shaped flange, and then the arc-shaped flange and the web are welded together to obtain the arc-shaped parts.

[0095] The length of the raw material refers to the fixed length of the raw material, and the fixed length of the raw material includes fixed length and customized length. For finished product raw material or plate raw material, the width is generally fixed. The width of the finished product raw material is directly determined according to the material specification, and the width of the plate raw material is generally 1.5 meters, 2 meters or 2.5 meters. Among the length of the finished product raw material or the plate raw material, 6 meters and 12 meters are the absolute mainstream specifications, and other common fixed lengths such as 9 meters, 10 meters, 11 meters and 13 meters are also produced. In some cases, the length can be customized according to actual needs, i.e. different customized lengths.

[0096] The clamping loss refers to the loss of the raw material caused by the clamping of the raw material by the machine tool during the bending process. The clamping loss includes the clamping length at the first end and the clamping length at the tail end. The clamping length at both ends is generally 100mm-300mm, which can be determined according to the cross-sectional information corresponding to the material specification and the workshop equipment. This is because different processing equipment is used in actual processing, and different equipment corresponds to different clamps. If the clamp used by the workshop equipment is fixed, that is, the clamping length during the bending is fixed, in this case, the clamping loss is directly determined according to the workshop equipment. If the clamp used by the workshop exists in multiple or the clamp can be flexibly replaced, then according to the cross-sectional information corresponding to the material specification and the workshop equipment, for example, the national standard model of common section steel such as H-shaped steel, angle steel and channel steel is associated with different clamps, and then the matching clamp is selected according to the material specification of the part in the actual processing process, and the clamping loss is determined according to the clamping length of the clamp, thereby avoiding material waste or processing interruption caused by clamping problems, and ensuring stable clamping.

[0097] Specifically, it can also be understood that, for the sake of convenience, the workshop will generally process the finished steel directly purchased according to the national standard in actual processing, and will process the pure steel plate for special customization that does not meet the national standard, and different workshops have different processing capacities for raw materials. Therefore, when performing material nesting optimization on the arc-shaped parts in each second-level group, the processing capacity of the workshop equipment needs to be considered, such as the space condition of the workshop and the model of the roll bending machine, so as to ensure that the length of the raw material will not exceed the processing capacity of the workshop equipment, that is, the length of the raw material needs to be greater than the lower limit value of the processing capacity of the workshop equipment and less than or equal to the upper limit value of the processing capacity of the workshop equipment.

[0098] In some embodiments, after determining the length of the raw material to be used, the material nesting is generated to generate a processing schedule according to the raw material length, the clamping loss and the common bending radius for each second-level group, specifically including:

[0099] Step S151, for each second-level group, determining the category of the target raw material and the clamping loss according to the material information of any arc-shaped part in the group, and determining the initial length of the target raw material according to the processing capacity of the workshop equipment.

[0100] The material information includes material specification and material grade; the type of the raw material includes finished raw material and plate raw material, and the fixed length and the customized length of the raw material.

[0101] Specifically, for all arc-shaped parts in each second-level group, since the second-level group is a group further subdivided according to the opening direction and the bending radius on the premise of 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 arc-shaped 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 the material information of the arc-shaped part, such as material specification C12 and material grade Q235B, and by matching with the national standard, it is found that the material specification of the arc-shaped part of the second-level group belongs to the national standard, at this time, the finished raw material can be directly purchased for processing, that is, the raw material is a finished raw material; on the contrary, if the material specification of the arc-shaped part of the second-level group does not belong to the national standard, that is, a non-national standard material specification, at this time, the arc-shaped part may need to be customized according to the non-national standard material specification with a plate raw material.

[0102] More specifically, for all parts in each second-level group, after determining the material information of the arc-shaped part, the type of the target raw material can be further determined according to the material information, whether to use a finished raw material or a plate raw material, and the clamping loss that can stably clamp the target raw material can be determined according to the specific cross-sectional information in the material information. Then, the initial length of the target raw material is further determined according to the processing capacity of the workshop equipment, to ensure that the length of the target raw material does not exceed the upper limit of the current processing capacity, for example, the upper limit of the processing capacity of a certain workshop equipment is to process an 8-meter-long raw material, at this time, the processing plan can only use a 6-meter-long finished raw material and a plate raw material; for another example, the upper limit of the processing capacity of a certain workshop equipment is to process a 13-meter-long raw material, at this time, the processing plan can use a 6-meter-long, a 9-meter-long, and a 12-meter-long finished raw material and a plate raw material, at this time, the 12-meter-long raw material can be preferentially selected, because using a 12-meter-long raw material can further save the waste of the raw material of the clamping part at both ends compared with using two 6-meter-long raw materials.

[0103] It should be noted that in some special cases, if a certain arc-shaped part is a non-national standard material specification, but the non-national standard material specification is close to a certain national standard material and the customer side also accepts the replacement with the similar national standard specification, at this time, the finished raw material can also be directly purchased according to the similar national standard specification.

[0104] Step S152, calculating the sum of the arc lengths of all arc-shaped parts in the group.

[0105] Specifically, the sum of the arc lengths of all arc-shaped parts in the second-level group is calculated, that is, the arc lengths of each arc-shaped part in the group are added together.

[0106] Step S153, determining the required number of target raw materials according to the sum of the arc lengths and the clamping loss, and calculating the utilization rate of each target raw material for processing at least one arc-shaped part, and generating a new processing plan table when the utilization rate of all arc-shaped parts of the target raw material meets the preset condition.

[0107] Specifically, there is a clamping loss for each raw material, and the sum of the arc lengths of the arc-shaped parts that can be processed on each raw material accounts for how much of the raw material, which can clearly and accurately reflect the utilization rate of the raw material. Therefore, in order to improve the utilization rate of the raw material, 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.

[0108] Further, the determining the required number of target raw materials according to the sum of the arc lengths and the clamping loss in step S153 can be that if the sum of the arc lengths is less than the difference between the initial length of the target raw material and the clamping loss, it is determined that the required number of target raw materials is 1, if the utilization rate of 1 target raw material is greater than a first preset utilization rate threshold, the initial length of the target raw material is kept unchanged, otherwise the length of the target raw material is replaced from the initial length to other fixed length or customized length according to the sum of the arc lengths. The first preset utilization rate threshold can also be that if the sum of the arc lengths is greater than the difference between the initial length of the target raw material and the clamping loss, it is determined that the required number of target raw materials is greater than 1, and it is necessary to ensure that the utilization rate of each target raw material is greater than a second preset utilization rate threshold, in addition, when there are multiple target raw materials, if the utilization rate of the last raw material is too low, the remaining several arc-shaped parts can be replaced or customized to other length of raw material according to the actual sum of the arc lengths, so as to avoid waste of raw materials. The first preset utilization rate threshold is generally set to 93%, and the second preset utilization rate threshold is generally set to 90%, which can also be adjusted to other values according to actual needs, and the present disclosure does not limit this.

[0109] The processing method of the arc-shaped part deeply fuses a three-dimensional model, a geometric algorithm and an optimized nesting strategy, forms a highly intelligent and refined arc-shaped part processing preparation method, and can quickly and accurately divide a plurality of arc-shaped parts of different specifications, different grades, different orientations and different bending radii into a plurality of groups of arc-shaped parts that can be combined for processing, thereby providing a powerful technical tool for the digital transformation and cost reduction and efficiency improvement of the building steel structure industry. The method first automatically analyzes, extracts and filters arc-shaped parts of various types and grades corresponding to the three-dimensional model corresponding to the processing plan, and quickly obtains the arc length and bending radius of the arc-shaped part by analyzing the geometric characteristics of each arc-shaped part. Then, the opening orientation of the arc-shaped part is automatically determined based on the size of the bending radius between different control points on the arc-shaped part, the processing requirements of each part are converted from an absolute bending radius value to a flexible radius interval, and the processing grouping of the arc-shaped part is quickly realized. Finally, after the arc-shaped parts are grouped in the first and second levels according to the opening orientation and the bending radius fluctuation range, the nesting method in each second-level group is optimized, the optimal processing plan table is generated with the least number of raw materials and the highest utilization rate of single raw material, the utilization rate of raw materials and the processing efficiency are greatly improved, and the actual workshop conditions are fully considered, so that the adaptability is good.

[0110] Figure 4a is a flowchart of the method provided by the present disclosure for identifying the opening orientation of each arc-shaped part, Figure 4b is a schematic view of an arc-shaped part provided by the present disclosure, Figure 4c is a schematic view of another arc-shaped part provided by the present disclosure; see Figure 4b and Figure 4c , the arc-shaped parts are both arc-shaped channel steel parts, specifically, Figure 4b is an arc-shaped part with an opening orientation facing the center of the circle, Figure 4c is an arc-shaped part with an opening orientation facing away from the center of the circle.

[0111] see Figure 4a , the method comprises:

[0112] Step S41, determining the bending radius of each arc-shaped part according to the geometric information of each arc-shaped part.

[0113] Specifically, if the geometric information is first geometric information, 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 equal to 2, and the fitting circular arc radius of the control points is calculated as the bending radius by using a geometric fitting algorithm when the number of control points of any part is greater than 2. Taking a channel steel part as an example, three control points on the web are randomly taken and the fitting circular arc radius of the three control points is calculated as the bending radius.

[0114] See Figure 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.

[0115] 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.

[0116] Step S42: Extract the centerline of each arc-shaped part and calculate the center bending radius corresponding to each centerline.

[0117] 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.

[0118] See Figure 4b, the center line of the arc-shaped channel steel part is a circular arc formed by connecting a plurality of center points of cross sections, and the circular arc is connected by points M1, M2 and M3, M1 is the center point of the rectangle formed by end points A1, B1, C1 and D1 of the part, M2 is the center point of the rectangle corresponding to the cross section at the center of the part, and M3 is the center point of the rectangle formed by end points F1, G1, H1 and I1 of the part. The center bending radius corresponding to each center line can be calculated by taking points M1, M2 and M3 as three control points, and the center bending radius is the radius length between the circular arc M1-M3 and the corresponding center, that is, the distance from the center O2 to any point on the circular arc M1-M3, such as the length of the line segment O2-M1, wherein the center O1 and the center O2 are on the same vertical line.

[0119] Referring to Figure 4c , the center line of the arc-shaped channel steel part is a circular arc formed by connecting a plurality of center points of cross sections, and the circular arc is connected by points M4, M5 and M6, M4 is the center point of the rectangle formed by end points A2, B2, C2 and D2 of the part, M5 is the center point of the rectangle corresponding to the cross section at the center of the part, and M6 is the center point of the rectangle formed by end points F2, G2, H2 and I2 of the part. The center bending radius corresponding to each center line can be calculated by taking points M4, M5 and M6 as three control points, and the center bending radius is the radius length between the circular arc M4-M6 and the corresponding center, that is, the distance from the center O4 to any point on the circular arc M4-M6, such as the length of the line segment O4-M4, wherein the center O3 and the center O4 are on the same vertical line.

[0120] Step S43, according to the size of the bending radius and the center bending radius of each arc-shaped part, the opening direction of each arc-shaped part is determined, if the bending radius is greater than the center bending radius, the opening direction is opposite to the center direction, if the bending radius is less than the center bending radius, the opening direction is away from the center direction.

[0121] Specifically, step S41 can determine the bending radius of the part, denoted as RK, and step S42 can determine the center bending radius at the center line of the part, denoted as RZ, if RK>RZ, it indicates that the opening direction is opposite to the center, if RK<RZ, it indicates that the opening direction is away from the center. Referring to 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 opposite to the center direction; referring to 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 direction.

[0122] Figure 5The complete operator set diagram for identifying the opening direction of each arc-shaped part is provided in the present disclosure; taking a channel steel part as an example, when implementing the method for identifying the opening direction of each arc-shaped part in steps S41-S43 based on Grasshopper, the layout of each part operator is specifically referred to Figure 5 , that is, the complete operator for identifying the opening direction of each arc-shaped part includes:

[0123] (1) selecting an object, which can be a target part, such as any arc-shaped part in a certain arc-shaped part set;

[0124] (2) obtaining the object center line, that is, the center line of each arc-shaped part, by using the Object Cent Line component, obtaining the start point and end point of the center line by using the End Points component, obtaining the middle point of the center line by using the Curve Middle component, and performing 3-point arc drawing by using the Arc 3pt component, that is, creating an arc for the start point, the middle point, and the end point, obtaining the radius of the arc, and recording it as radius A; see Figure 4b , the line segment M1-M3 is the center line of the channel steel arc-shaped part, the point M1 corresponds to the start point of the center line, the point M2 corresponds to the middle point of the center line, and the point M3 corresponds to the end point of the center line, and the radius A is the length of the line segment O2-M1; see Figure 4c , the line segment M4-M6 is the center line of the channel steel arc-shaped part, the point M4 corresponds to the start point of the center line, the point M5 corresponds to the middle point of the center line, and the point M6 corresponds to the end point of the center line, and the radius A is the length of the line segment O4-M4.

[0125] (3) decomposing the object attribute by using the Deconstruct Beam component, decomposing the curve and extracting the control points by using the Explode Curve component, extracting the objects in the list from the list storing the control points by using the List Item component, that is, the three control points of the channel steel part web limb back control line, and performing 3-point arc drawing by using the Arc 3pt component, that is, creating an arc for the three control points to obtain the radius of the arc, and recording it as radius B; see Figure 4b , the line segment A1-F1 is the web limb back control line of the channel steel arc-shaped part, the points A1, E1, and F1 are the three control points, and the radius B is the length of the line segment O1-A1; see Figure 4c , the line segment A2-F2 is the web limb back control line of the channel steel arc-shaped part, the points A2, E2, and F2 are the three control points, and the radius B is the length of the line segment O3-A2.

[0126] (4) Using the Larger Than component to compare the size of the first number "radius A of the center line" and the second number "radius B of the control line", and then using the Dispatch component to split the object list into a list of "arc-shaped parts with opening facing away from the center" and a list of "arc-shaped parts with opening facing towards the center" according to the radius comparison result.

[0127] In the above method of identifying the opening direction of each arc-shaped part, the "part limb back control line" and the "part center line" are selected as the judgment reference based on the asymmetric properties of the cross sections of different specifications of steel, that is, the opening direction of the arc-shaped part is determined by the relative size relationship of the geometric characteristics of the part itself, avoiding subjective speculation of manual drawing and improving the accuracy and robustness of the determination. At the same time, the corresponding radius acquisition strategies "directly read the radius attribute" or "multi-control point geometric fitting" are provided for three-dimensional models of different detail levels, enhancing the applicability of the method. In addition, the automatic determination of the opening direction of each arc-shaped part based on Grasshopper can completely liberate engineers from tedious and error-prone manual identification and determination, greatly shortening the data processing time before processing, and is a key link to realize digital intelligent manufacturing of steel structure.

[0128] Figure 6 is a flowchart of a method of dividing a second-level group provided by the present disclosure. After the arc-shaped parts are grouped in the first level according to the opening direction, further grouping in the second level according to the bending radius is needed, that is, for each first-level group, the allowable bending radius fluctuation range of each arc-shaped part in the group that meets the preset arch height machining error requirement is calculated, the arc-shaped parts with intersection of the bending radius fluctuation range are divided into the same second-level group, and a common bending radius is determined for each second-level group.

[0129] Referring to Figure 6 , the method of dividing the second-level group, that is, the bending radius fluctuation range of each arc-shaped part in the group is calculated based on the preset arch height machining error requirement for each first-level group, and the arc-shaped parts with intersection of the bending radius fluctuation range are divided into the same second-level group, which specifically includes the following steps:

[0130] Step S61, 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 machining error requirement.

[0131] Specifically, it can be understood that, in order to reduce the number of mold replacement, the same bending radius is used as much as possible for each group, and the present disclosure proposes to divide the same or similar bending radius into a small group, and calculate the radius that still meets the machining error after the bending radius changes according to the machining error, that is, the bending radius fluctuation range of each arc-shaped part in the group is calculated based on the preset camber machining error requirement, and grouping is performed based on the bending radius fluctuation range.

[0132] Specifically, it can also be understood that, for each first-level group, the bending radius fluctuation range of each arc-shaped part in the group is calculated based on the preset camber machining error requirement, specifically including:

[0133] Step S611, the arc length and bending radius of each arc-shaped part are extracted according to the geometric information of each arc-shaped part, and the actual camber height of each arc-shaped part is calculated according to the arc length and bending radius.

[0134] Wherein, the actual camber height refers to the vertical distance from the midpoint of the chord formed by the two endpoints of the curved segment of the arc-shaped part to the top of the corresponding circular arc, and when the actual camber height of each arc-shaped part is calculated according to the arc length and bending radius, the formula for calculating the actual camber height is , H represents the actual camber 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 first geometric information or second geometric information.

[0135] If the geometric information is the first geometric information, the arc length and bending radius of each arc-shaped part are extracted, including: determining the arc length of the arc-shaped part according to the length information of the first geometric information; determining the bending radius according to the part radius attribute of the first geometric information, or performing circular arc fitting according to the control points of the first geometric information and taking the fitting circular arc radius as the bending radius.

[0136] If the geometric information is the second geometric information, the arc length and bending radius of each arc-shaped part are extracted, including: taking the distance of the arc line between the two endpoints of the part outer boundary line as the part length, and performing circular arc fitting on the plurality of control points uniformly distributed on the part to take the fitting circular arc radius as the bending radius.

[0137] Step S612, calculating the theoretical camber height allowable range of each arc-shaped part according to the preset camber machining error and the actual camber height.

[0138] Wherein, the preset camber machining error refers to the machining precision of the steel structure, which is generally 1mm. If the actual camber height is H and the theoretical camber height is H_c, the theoretical camber height and the actual camber height need to satisfy |H_c - H|<= 1mm, for example, the actual camber height of a certain arc-shaped part is 5mm, and the allowable range of its theoretical camber height is [4mm, 6mm].

[0139] Step S613, according to the theoretical arch height allowable range and the arc length inverse solution of the bending radius corresponding to the bending radius fluctuation range.

[0140] Wherein, according to the relationship between arch height, arc length and bending radius, under the condition that the arc length is unchanged, the corresponding change interval 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 calculated theoretical arch height corresponding to any bending radius will not exceed the preset arch height machining error, that is, the calculated theoretical arch height and the actual arch height satisfy the condition |H_c - H|<= 1mm.

[0141] Figure 7 is the complete operator group diagram for calculating the bending radius fluctuation range provided by the present disclosure; taking a channel steel part as an example, based on Grasshopper, when implementing the "calculating the bending radius fluctuation range of each arc-shaped part in the group based on the preset arch height machining error requirement" method of step S61, the layout of each part of the operator is specifically referred to Figure 7 That is, the complete operator of the complete operator for calculating the bending radius fluctuation range includes:

[0142] (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 direction;

[0143] (2) Use the Deconstruct Beam component to decompose the object attribute, use the Explode Curve component to decompose the curve and extract the control points, use the List Item component to extract the objects in the list from the list storing the control points, that is, the three control points of the channel steel part web limb back control line, the three control points correspond to the first end control point, the middle control point and the tail end control point; use the Arc 3pt component to draw a circular arc with three points, that is, draw a circular arc with the three control points to obtain a circular arc curve, and use the Line component to draw a line with the first and last control points of the three control points on the web 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 vertical line of the part, and then use the nearest point Curve Closest Point component to calculate the intersection point of the vertical line and the circular arc curve, that is, the point on the corresponding circular arc curve of the part arch height.

[0144] (3) Use the Vector 2pt component to create a vector based on the midpoint of the vertical line and the intersection point of the vertical line and the circular arc curve, and then control the movement of the vector to realize the upward or downward movement of the intersection point of the vertical line and the circular arc curve.

[0145] (4) Using the Move component to move, calculating the position of the vector after moving 1mm in the forward direction, replacing the previous intermediate control point, and using the Arc 3pt component to draw a circular arc with three points, i.e. re-drawing a circular arc with three control points to obtain the circular arc radius; similarly, using the multiplication component and the Move component to move in the reverse direction, calculating the position of the vector after moving 1mm in the reverse direction, replacing the previous intermediate control point, and using the Arc 3pt component to draw a circular arc with three points, i.e. re-drawing a circular arc with three control points to obtain the circular arc radius;

[0146] (5) Using the Merge component to merge the list, merging the two circular arc radii obtained in step (4) into a "bend radius fluctuation range".

[0147] In step S32, it is determined whether there is a unique common subset of the bend radius fluctuation ranges of all arc-shaped parts in the group. If there is, all arc-shaped parts in the group are divided into a second-level group. If there is not, the number of second-level groups and the second-level grouping result are determined according to the intersection of the bend radius fluctuation ranges of each arc-shaped part in the group.

[0148] Specifically, it can be understood that arc-shaped parts with the same radius or similar radius are divided into a group. On the basis of ensuring the processing error, it is determined whether there is an intersection between the allowed fluctuation range [R_min, R_max] of the radius. The common intersection of the radius intervals of all parts in the current group is found, or the least common intersection of the radius intervals of all parts in the current group is found, so as to realize the stretch-bending processing of the arc-shaped parts with as few bend radii as possible.

[0149] Specifically, it can also be understood that when determining whether there is an intersection of the bend radius fluctuation ranges of each arc-shaped part, it is necessary to first determine whether there is a unique common subset. If there is a unique common subset, i.e. there is an overlapping part between all bend radius fluctuation ranges, the same processing radius can be used for the stretch-bending processing of all parts in the current group. If there is not a unique common subset, the number of groups and the grouping result need to be determined according to the intersection of the bend radius fluctuation ranges. For the case where there is not a unique common subset, there can be no overlapping part between all bend radius fluctuation ranges, i.e. there is no intersection between two bend radius fluctuation ranges. Alternatively, the overlapping part of part of the bend radius fluctuation ranges is different from other bend radius fluctuation ranges or other overlapping parts, so when there is not a unique common subset, grouping needs to be performed according to the specific intersection.

[0150] In some embodiments, when there is not a unique common subset, the number of groups and the grouping result are determined according to the intersection of the bend radius fluctuation ranges, i.e. the number of second-level groups and the second-level grouping result are determined according to the intersection of the bend radius fluctuation ranges of each arc-shaped part in the group, including:

[0151] Step a1, calculate the maximum number of disjoint intervals of all the bending radius fluctuation ranges in the group as the number of groups of the second-level grouping.

[0152] Wherein, the maximum number of disjoint intervals refers to how many intervals are disjoint with each other among all the intervals, that is, the maximum number of disjoint fluctuation ranges among all the bending radius fluctuation ranges.

[0153] Step a2, sort all the bending radius fluctuation ranges in the group from small to large to obtain a sequence of sorted bending radius fluctuation ranges.

[0154] Specifically, each bending radius fluctuation range is an interval, and the sorting can be directly sorted according to the size of the interval endpoints, that is, all the bending radius fluctuation ranges in the group are sorted from small to large, that is, the left endpoints of each bending radius fluctuation range are sorted from small to large, and when the left endpoints are the same, the right endpoints are sorted according to their size. For example, each bending radius fluctuation range is [R_min, R_max], the corresponding left endpoint is R_min and the right endpoint is R_max. Assuming that there are N bending radius fluctuation ranges in the current group, sorting from small to large is sorting the left endpoints from small to large, that is, sorting the R_min of the N bending radius fluctuation ranges from small to large, and when R_min is the same, sorting the right endpoints R_max from small to large, finally obtaining [R1_min, R1_max], [R2_min, R2_max], …, [RN_min, RN_max], wherein R1_min≤R2_min≤…≤RN_min.

[0155] Step a3, according to the number of groups of the second-level grouping, construct the second-level grouping for dividing the bending radius fluctuation range, and initialize each second-level grouping.

[0156] Specifically, the maximum number of disjoint intervals is denoted as K, that is, the number of groups of the second-level grouping is K; each group stores intervals in a list and maintains a value max_l and min_r, max_l represents the maximum value of the left endpoints of all intervals in the group and the initialization value of max_l is 0, min_r represents the minimum value of the right endpoints of all intervals in the group and the initialization value of min_r is +∞, for example, the left endpoints of the intervals of the first second-level grouping K1.max_l=0, the right endpoints K1.min_r=∞, the left endpoints of the intervals of the second second-level grouping K2.max_l=0, and the right endpoints K2.min_r=∞.

[0157] Step a4, based on the sequence of sorted bending radius fluctuation ranges, sequentially traverse each second-level grouping and update the second-level grouping when the merging condition is met, until all the bending radius fluctuation ranges are completed for the second-level grouping.

[0158] Specifically, the merging condition is satisfied when the left end point of the bending radius fluctuation range is less than the right end point of any second-level grouping interval; for [R1_min, R1_max], [R2_min, R2_max], …, [RN_min, RN_max], each second-level grouping is traversed in turn with each bending radius fluctuation range until the next second-level grouping is traversed when the current second-level grouping does not satisfy the merging condition:

[0159] Suppose that the first bending radius fluctuation range [R1_min, R1_max] traverses the first second-level grouping, first judge whether the left end point R1_min of the bending radius fluctuation range [R1_min, R1_max] is less than K1.min_r, the right end point 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, and at the same time, the left end point K1.max_l of the first second-level grouping interval is updated according to the left end point R1_min of the bending radius fluctuation range, max(K1.max_l, R1_min), and the right end point K1.min_r of the first second-level grouping interval is updated according to the right end point R1_max of the bending radius fluctuation range, min(K1.min_r, R1_max) = R1_max;

[0160] Then, when the second bending radius fluctuation range [R1_min, R1_max] traverses the first second-level group, it is first determined whether the left end point R2_min of the bending radius fluctuation range [R2_min, R2_max] is less than K1.min_r, the right end point of the first second-level group interval. If R2_min<=R1_max, the second bending radius fluctuation range sequence [R2_min, R2_max] is also divided into the first second-level group, and the left end point K1.max_l of the first second-level group interval is updated according to the left end point R2_min of the bending radius fluctuation range, that is, K1.max_l=max(K1.max_l, R2_min), and the right end point K1.min_r of the first second-level group interval is updated according to the right end point R2_max of the bending radius fluctuation range, that is, K1.min_r=min(K1.min_r, R2_max). If R2_min>R1_max, the first second-level group will be grouped, containing only one bending radius fluctuation range [R1_min, R1_max], and the second bending radius fluctuation range [R2_min, R2_max] will traverse the second second-level group and be divided into the second second-level group, and the left end point K2.max_l of the second second-level group interval is updated according to the left end point R2_min of the bending radius fluctuation range, that is, K2.max_l=max(K2.max_l, R2_min), and the right end point K2.min_r of the second second-level group interval is updated according to the right end point R2_max of the bending radius fluctuation range, that is, K2.min_r=min(K2.min_r, R2_max)=R2_max.

[0161] Finally, the above steps are repeated for each judgment bending radius fluctuation range, until all bending radius fluctuation ranges are grouped, 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]}.

[0162] Step S33, a common bending radius is determined for each second-level group.

[0163] Specifically, if there is a unique common subset of the bending radius fluctuation ranges of the arc-shaped parts in the group, a bending radius in the common subset is selected as the machining radius of the current group, and if there is no unique common subset, a bending radius in the common subset of each second-level group is selected as the machining radius of the current second-level group.

[0164] For example, after all the bending radius fluctuation ranges are completed for the second-level grouping, 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]}. The corresponding interval in each second-level group is the common subset of all the bending radius fluctuation ranges in the second-level group. For example, the interval [K1.max_l, K1.min_r] of the first second-level group, the intersection of the bending radius fluctuation range [R1_min, R1_max] and the bending radius fluctuation range [R2_min, R2_max] is [K1.max_l, K1.min_r]. When determining the common bending radius, the interval [K1.max_l, K1.min_r] can be directly selected.

[0165] In some embodiments, after determining the common bending radius of each second-level group, if there are multiple bending radii in the common subset, the standard mold radius of the workshop equipment can be determined, such as preferentially selecting the standard mold radius in the existing mold library of the workshop. In this way, when processing the group of parts, the existing mold can be directly called to realize true “zero mold change” or “minimum mold change” preparation time, and the efficiency is improved to the extreme. If there is only one bending radius in the common subset, the bending radius is taken as the common bending radius. At this time, if the common bending radius is a new radius, a new standard mold can be customized.

[0166] In the above-mentioned second-level grouping method, based on the geometric relationship among the arch height, the arc length, and the bending radius, the product quality requirement “arch height machining error” is accurately converted into the control parameter allowable range of the production process, that is, the allowable fluctuation range of the bending radius is inversely deduced according to the machining error, to ensure the executability and quality reliability of the final machining plan. At the same time, the second-level grouping of the arc-shaped parts is realized according to the allowable fluctuation range of the bending radius, each group is processed by using the common bending radius, to ensure that all the parts in the same second-level group can be processed by using the same mold, thereby significantly reducing the mold replacement times and improving the processing efficiency. Moreover, compared with the traditional “one material one bending” mode, the present disclosure finds the common machining radius for each second-level group, so that multiple arc-shaped parts can be continuously bent and processed on one long raw material, the clamping loss is reduced from “multiple” to “one”, and the raw material utilization rate is greatly improved.

[0167] Figure 8 is a structural schematic diagram of an arc-shaped part machining system provided by the present disclosure. Referring to Figure 8 , the system 800 comprises:

[0168] The model analysis unit 810 is configured to obtain a three-dimensional model of a target machining plan, and analyze and extract parameter information of all parts from the three-dimensional model, the parameter information including material information and geometric information.

[0169] The feature grouping unit 820 is configured to divide all parts into different categories of part sets according to material specifications and grades based on the material information, and perform arc feature recognition on each category of part sets based on the geometric information, to obtain different categories of arc part sets.

[0170] The orientation grouping unit 830 is configured to identify an opening orientation of each arc part, and divide each arc part set into two first-level groups according to different opening orientations, the opening orientations including a direction facing a center and a direction away from the center, the center being a center of the arc part.

[0171] The radius grouping unit 840 is configured to, for each first-level group, calculate a bending radius fluctuation range of each arc part in the group based on a preset camber machining error requirement, divide arc parts with the same bending radius fluctuation range into a same second-level group, and determine a common bending radius for each second-level group.

[0172] The machining planning unit 850 is configured to, for each second-level group, generate a machining plan table according to a raw material length, a clamping loss, and the common bending radius, the machining plan table being used to guide machining of multiple arc parts on a same raw material using the common bending radius.

[0173] The above-described detailed description of the arc part machining system can be found in the description of the related method steps in the above embodiments, and repeated descriptions are omitted. The embodiments of the arc part machining method and the arc part machining system described above are merely illustrative, and the "unit" and "module" used as separate components can be a combination of software and / or hardware that achieves a predetermined function, and can or can not be physically separated. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments. Those skilled in the art can understand and implement without creative labor.

[0174] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present disclosure, but not to limit them; although the present disclosure has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should be covered within the protection scope of the present disclosure.

Claims

1. A method of machining an arcuate part, characterized by, The method comprises: acquiring a three-dimensional model of a target machining plan, and parsing and extracting parameter information of all parts from the three-dimensional model, the parameter information comprising 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 performing arc feature recognition on each category of part sets based on the geometric information to obtain different categories of arc part sets; identifying the opening direction of each arc part, and dividing each arc part set into two first-level groups according to the difference in opening direction, the opening direction comprising: facing the center direction and facing away from the center direction, the center being the center of the arc part; for each first-level group, calculating the bending radius fluctuation range of each arc part in the group based on a preset arch height machining error requirement, dividing the arc parts with intersecting bending radius fluctuation ranges into the same second-level group, and determining a common bending radius for each second-level group; for each second-level group, generating a machining plan table according to the raw material length, the clamping loss and the common bending radius, the machining plan table being used to guide the machining of multiple arc parts on the same raw material using the common bending radius.

2. The method of machining an arcuate part according to claim 1, wherein The geometric information comprises first geometric information or second geometric information; parsing and extracting the parameter information of all parts from the three-dimensional model, comprising: if the three-dimensional model is a building information model containing parameterized attributes, connecting with an application programming interface of 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 comprising 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, extracting the material information and the second geometric information of all parts by reading and parsing the geometric model, the second geometric information comprising part length, control point position and control point number.

3. The method of claim 2, wherein the arc-shaped part is a tire. The arc feature recognition comprises: identifying arc parts based on the control point number and the part radius attribute, or identifying arc parts based on the control point number and the control point position by using a geometric fitting algorithm.

4. The method of claim 1, wherein the arc-shaped part is a tire. The identification of the opening direction of each arc part specifically comprises: determining the bending radius of each arc part according to the geometric information of each arc part; extracting the center line of each arc part and calculating the center bending radius corresponding to each center line; determining the opening direction of each arc part according to the size of the bending radius and the center bending radius of each arc part, wherein if the bending radius is greater than the center bending radius, the opening direction is facing the center direction, and if the bending radius is less than the center bending radius, the opening direction is facing away from the center direction.

5. The method of claim 1, wherein the arc-shaped part is a tire. The calculation of the bending radius fluctuation range of each arc part in the group based on the preset arch height machining error requirement, the division of the arc parts with intersecting bending radius fluctuation ranges into the same second-level group, and the determination of a common bending radius for each second-level group for each first-level group, comprising: For each first-level group, a bending radius fluctuation range of each arc-shaped part in the group is calculated based on a preset arch height machining error requirement; It is judged whether there is a unique common subset of the bending radius fluctuation ranges of all arc-shaped parts in the group, if there is, all arc-shaped parts in the group are divided into a second-level group, if not, the number of second-level groups and the second-level group result are determined according to the intersection condition of the bending radius fluctuation ranges of each arc-shaped part in the group; A common bending radius is determined for each second-level group.

6. The method of machining an arcuate part of claim 5, wherein, The method comprises the following steps: According to the geometric information of each arc-shaped part, the arc length and bending radius of each arc-shaped part are extracted, and the actual arch height of each arc-shaped part is calculated according to the arc length and bending radius; The theoretical arch height allowable range of each arc-shaped part is calculated according to the preset arch height machining error and the actual arch height; The bending radius fluctuation range corresponding to the bending radius is inversely solved according to the theoretical arch height allowable range and the arc length.

7. The method of claim 5, wherein the arc-shaped part is a tire. The method comprises the following steps: The maximum number of disjoint intervals of all bending radius fluctuation ranges in the group is calculated as the number of second-level groups; All bending radius fluctuation ranges in the group are sorted from small to large to obtain a sorted bending radius fluctuation range sequence; The second-level groups for dividing the bending radius fluctuation ranges are constructed according to the number of second-level groups, and each second-level group is initialized; Based on the sorted bending radius fluctuation range sequence, each second-level group is traversed in turn, and the second-level group is updated when the merging condition is met, until all bending radius fluctuation ranges are completed second-level grouping.

8. The method of claim 1, wherein the arc-shaped part is a tire. The material information includes material specifications and material grades; the types of raw materials include finished product raw materials and plate raw materials, and the fixed length and customized length of the raw material length.

9. The method of claim 8, wherein the arc-shaped part is a tire. The method comprises the following steps: For each second-level group, the category and clamping loss of the target raw material are determined according to the material information of any arc-shaped part in the group, and the initial length of the target raw material is determined according to the processing capacity of the workshop equipment; The sum of the arc lengths of all arc-shaped parts in the group is calculated; The required number of target raw materials is determined according to the sum of the arc lengths and the clamping loss, and the utilization rate of at least one arc-shaped part processed on each target raw material is calculated, and the arc-shaped part allocation result when all target raw materials meet the preset condition is generated to generate a new processing plan table.

10. A system for machining an arcuate part, characterized by The system comprises: A model analysis unit is configured to obtain a three-dimensional model of a target processing plan, analyze and extract parameter information of all parts from the three-dimensional model, and the parameter information includes material information and geometric information; A feature grouping unit is configured to divide all parts into different categories of part sets based on the material information, and perform arc-shaped feature recognition on each category of part set based on the geometric information to obtain different categories of arc-shaped part sets. A grouping unit is configured to identify an opening direction of each arc-shaped part and divide each set of arc-shaped parts into two first-level groups according to the different opening directions, wherein the opening directions include a direction facing a center and a direction away from the center. A radius grouping unit is configured to, for each first-level group, calculate a bending radius fluctuation range of each arc-shaped part in the group based on a preset arch height machining error requirement, divide arc-shaped parts having an intersection of the bending radius fluctuation range into a same second-level group, and determine a common bending radius for each second-level group. A machining planning unit is configured to, for each second-level group, generate a machining schedule according to a raw material length, a clamping loss, and the common bending radius, and the machining schedule is used to guide machining of multiple arc-shaped parts using the common bending radius on a same raw material.

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