Cable roundness detection method and device based on three-dimensional model slicing and electronic equipment

Abstract

The application provides a cable roundness detection method and device based on three-dimensional model slicing and electronic equipment, and relates to the technical field of cable quality detection. The method comprises the following steps: constructing a three-dimensional STL model of a cable to be detected; performing plane slicing on the three-dimensional STL model of the cable along the axial direction of the cable; for any one slice, extracting the maximum connected contour of the cable slice as a target cross-sectional contour, and fitting the contour points on the target cross-sectional contour to obtain a fitted center and a fitted radius; determining a point-to-point radius difference relative index and a maximum deviation relative index for double-threshold joint determination to determine a roundness evaluation result. The application extracts an effective cross section based on three-dimensional model slicing and fitting parameters, can eliminate contour edge interference, and accurately obtains cable cross-sectional geometric data; the roundness is determined by double-threshold joint determination of two relative indexes, local and overall deformation are considered, the accuracy and reliability of roundness detection are improved, and continuous, accurate and non-contact detection of roundness is realized.

Description

Technical Field

[0001] This invention relates to the field of cable quality inspection technology, and in particular to a method, apparatus and electronic equipment for cable roundness inspection based on three-dimensional model slicing. Background Technology

[0002] With the continuous improvement of power equipment manufacturing capabilities, cable products are widely used in power transmission and distribution systems, rail transportation, marine engineering, and high-end equipment manufacturing. During the cable production process, the geometrical accuracy of the insulation layer, semi-conductive layer, and conductor layer directly affects its electrical insulation performance, mechanical stability, and long-term service reliability. Among these, roundness is one of the important indicators for measuring the geometrical consistency of the cable cross-section.

[0003] During cable manufacturing, factors such as extrusion molding, sheath tension fluctuations, core eccentricity, mold errors, or uneven cooling can cause problems like localized out-of-roundness of the cable cross-section, surface undulations, localized bulges, or depressions. These problems can further lead to uneven insulation thickness, localized electric field distortion, mechanical stress concentration, and reduced service life. Therefore, accurate detection of cable roundness has significant engineering application value.

[0004] Existing technologies typically employ methods for detecting cable roundness, including contact measurement, cross-sectional measurement based on two-dimensional images, and offline geometric analysis methods for single cross-sections. None of these methods can achieve accurate, continuous, and non-contact measurement of cable roundness. Summary of the Invention

[0005] This invention provides a method, apparatus, and electronic device for detecting cable roundness based on three-dimensional model slicing, to solve the problem that existing methods for detecting cable roundness cannot achieve accurate, continuous, and non-contact detection.

[0006] In a first aspect, embodiments of the present invention provide a cable roundness detection method based on three-dimensional model slices, comprising: Construct a three-dimensional STL model of the cable to be tested; The 3D STL model of the cable is sliced ​​along the cable axis to obtain multiple cable slices; For any cable slice, the maximum connected contour of the cable slice is extracted as the target cross-sectional contour, and the contour points on the target cross-sectional contour are fitted to obtain the fitted circle center and fitted radius. Based on the fitted circle center and fitted radius, the relative index of the radius difference between points and the relative index of the maximum deviation are determined. Based on the relative index of the radius difference between points and the relative index of the maximum deviation, a dual threshold joint judgment is performed to determine the roundness evaluation result corresponding to the cable slice.

[0007] Secondly, embodiments of the present invention provide a cable roundness detection device based on three-dimensional model slices, comprising: The model building module is used to build a 3D STL model of the cable to be tested. The slicing module is used to slice the 3D STL model of the cable along the cable axis to obtain multiple cable slices. The evaluation module is used to extract the maximum connected contour of any cable slice as the target cross-sectional contour, and fit the contour points on the target cross-sectional contour to obtain the fitted circle center and fitted radius. Based on the fitted circle center and fitted radius, the relative index of the radius difference between points and the relative index of the maximum deviation are determined. Based on the relative index of the radius difference between points and the relative index of the maximum deviation, a dual threshold joint judgment is performed to determine the roundness evaluation result corresponding to the cable slice.

[0008] Thirdly, embodiments of the present invention provide an electronic device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the cable roundness detection method based on three-dimensional model slices as described in the first aspect or any possible implementation of the first aspect.

[0009] This invention provides a method, apparatus, and electronic device for cable roundness detection based on 3D model slicing. The method includes: constructing a 3D STL model of the cable to be detected; slicing the 3D STL model along the cable axis to obtain multiple cable slices; for any given cable slice, extracting the maximum connected contour as the target cross-sectional contour, and fitting the contour points on the target cross-sectional contour to obtain the fitted center and fitted radius; determining the relative index of the radius difference between points and the relative index of the maximum deviation based on the fitted center and fitted radius, and performing a dual-threshold joint judgment based on the relative index of the radius difference between points and the relative index of the maximum deviation to determine the roundness evaluation result corresponding to the cable slice. This application relies on 3D STL modeling and axial slicing to completely restore the physical shape of the cable, with cross-sectional data closely matching the actual cable morphology. By selecting the maximum connected contour of the slice and fitting the contour point circle, invalid edge interference such as outer sheath damage and burrs is accurately removed, and the reliability of the circle center and radius solution is high. Finally, a dual relative deviation index combined with a threshold is used to determine roundness, taking into account both local point fluctuations and overall maximum deformation, effectively improving the roundness detection accuracy and fault tolerance. It can realize automated quantitative evaluation of cable cross-section roundness, with high detection efficiency, small human error, and is suitable for batch cable geometric quality inspection. Attached Figure Description

[0010] Figure 1 This is a flowchart illustrating the implementation of a cable roundness detection method based on three-dimensional model slicing provided in an embodiment of the present invention. Figure 2This is a top view of the detection results corresponding to the method in this embodiment of the invention; Figure 3 This is a schematic diagram of the cable roundness detection device based on three-dimensional model slicing provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0011] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0012] See Figure 1 The document illustrates a flowchart of a cable roundness detection method based on three-dimensional model slicing provided by an embodiment of the present invention, detailed below: refer to Figure 1 The above-mentioned cable roundness detection method based on three-dimensional model slicing includes: S101: Construct a 3D STL model of the cable to be tested; Specifically, the cable to be tested can be scanned to collect point cloud data on the surface of the cable. The point cloud data can be preprocessed, and triangulation and STL surface reconstruction can be performed based on the preprocessed point cloud data to form a three-dimensional STL model and export it as an STL file.

[0013] The exported 3D STL model is triangulated, cleaned, and topologically repaired to remove invalid elements, duplicate points, and abnormal connections, resulting in a standard 3D STL model suitable for subsequent analysis.

[0014] S102: Perform planar slicing on the 3D STL model of the cable along the cable axis to obtain multiple cable slices; Based on the axial direction of the cable, select the detection range to be analyzed, and set the start position, end position, and slice step size. For example, multiple equally spaced slice positions can be continuously generated at fixed intervals within a certain range along the Y-axis of the cable.

[0015] In one possible embodiment, the detection interval is set to Y=250mm to Y=350mm, the slicing step size is set to 2mm, and the generation... In one possible embodiment, the starting slice is ≥50mm from the beginning of the cable and the ending slice is ≥50mm from the end of the cable, completely avoiding the clamping deformation and end face burr areas. At each slice location, a plane perpendicular to the cable axis is constructed, and its intersection with the 3D STL model is calculated to obtain the corresponding cross-sectional intersection line. The normal vector of the slice plane is consistent with the cable axis. When the cable principal axis is the Y-axis, the slice plane can be set as a plane with a normal vector of (0,1,0).

[0016] S103: For any cable slice, extract the maximum connected contour of the cable slice as the target cross-sectional contour, and fit the contour points on the target cross-sectional contour to obtain the fitting circle center and fitting radius; determine the relative index of the radius difference between points and the relative index of the maximum deviation based on the fitting circle center and fitting radius, and perform a dual threshold joint judgment based on the relative index of the radius difference between points and the relative index of the maximum deviation to determine the roundness evaluation result corresponding to the cable slice.

[0017] This application adopts a dual-index joint judgment, which takes into account both local minor distortions and overall large deformations, and solves the problem of easy omission or misjudgment by a single index, realizing automated, quantitative and high-precision evaluation of cable cross-section roundness.

[0018] After extracting the target cross-sectional profile, the profile points are projected onto the cross-sectional plane. For a cable with the Y-axis as its axial direction, the cross-sectional fitting plane can be the XZ plane. Let the discrete points of the profile be... .

[0019] The least squares circle fitting method is used to establish the circle equation: Solving parameters using least squares , , Thus, the center of the fitted circle is obtained. and fitted radius : If the fitting radius is less than or equal to zero, the fitting is considered to have failed, and no valid result is output for the current section.

[0020] In one possible implementation, S103 may include: S1031: Determine the actual distance between each contour point on the target cross-section contour and the center of the fitted circle; After obtaining the fitted circle, the actual distance from each contour point to the center of the fitted circle is further calculated: Based on this, the relative index of the radius difference between points and the relative index of the maximum deviation are calculated.

[0021] S1032: Determine the relative index of the radius difference between points based on the fitted radius and each actual distance; S1033: Determine the maximum deviation relative index based on the fitting radius and each actual distance.

[0022] The relative index of inter-point radius difference is used to characterize the overall dispersion of the cross-sectional profile points relative to the fitted circle, targeting overall deformations such as periodic ripples, bamboo-like defects, and surface pitting. The relative index of maximum deviation is used to characterize the maximum deviation of the most unfavorable point relative to the fitted circle, targeting local defects such as bulges, pits, elliptical deformation, and eccentricity. These two indices cover all typical roundness defects in cable production, forming a blind-zone-free detection system. By simultaneously constraining two preset thresholds, the system comprehensively determines whether the cross-sectional roundness is acceptable, effectively improving the accuracy of roundness detection.

[0023] In one possible implementation, S1032 may include: 1. Based on the fitted radius and each actual distance, the relative index of the radius difference between points is obtained by combining the first formula; The first formula may include: in, This is a relative index of the difference in radii between points. The fitting radius is... For the first The actual distance between each contour point and the center of the fitted circle.

[0024] Iterate through all measured radii and extract the maximum value. and minimum value The difference between the two is the absolute roundness error of the cross-section, which characterizes the maximum total fluctuation of the profile in the radial direction. Dividing the absolute roundness error by the fitted radius... Obtain dimensionless relative indices This eliminates the influence of different cable diameters on the evaluation results, makes the indicators comparable across specifications, reduces the scale effect under different cable diameter conditions, and enhances the universality of the evaluation.

[0025] In one possible implementation, S1033 includes: 1. Based on the fitted radius and each actual distance, the maximum deviation relative index is obtained by combining the second formula; The second formula may include: in, This is the relative index of the maximum deviation.

[0026] Iterate through the single-point absolute deviations of all contour points and extract the maximum value. This value represents the absolute deviation at the most unfavorable point on the cross-section. The maximum absolute deviation is divided by the fitted radius. To obtain relative indicators This eliminates the influence of different cable diameters on the evaluation results.

[0027] It characterizes the total radial fluctuation amplitude of the cross section and reflects the overall degree of deformation of the profile; These two indicators characterize the maximum deviation of a single point from an ideal circle, specifically reflecting the severity of local defects. They cover all typical roundness defects from the dimensions of "overall deformation" and "local extreme values," achieving 100% detection coverage. Furthermore, both indicators are relative, allowing for consistent evaluation under different cable diameter conditions.

[0028] In one possible implementation, S103 may include: S1034: If the relative index of the difference in radius between points is not greater than the first threshold and the relative index of the maximum deviation is not greater than the second threshold, then the roundness evaluation result corresponding to the cable slice is determined to be qualified. S1035: Otherwise, the roundness evaluation result corresponding to the cable slice is determined to be unqualified.

[0029] The first threshold controls the overall radial fluctuation of the control section, ensuring that the cable's ellipticity, periodic bamboo-like texture, and other overall deformations are within allowable limits. The second threshold controls the degree of local extreme value deviation of the control section, ensuring that there are no fatal defects such as individual bulges or pits that could lead to insulation breakdown or withstand voltage failure. The relative index of the point radius difference is used. and the relative index of maximum deviation The two indicators are compared with the corresponding thresholds. The cable slice is considered to be qualified only when both indicators are within the threshold range. If either indicator exceeds the threshold, it is considered unqualified. This method can achieve high-precision and accurate detection of cable roundness.

[0030] In one possible implementation, the first threshold can be 1.08% and the second threshold can be 1.91%.

[0031] The first threshold can be 1.08%, which translates to an outer diameter out-of-roundness of 2.16%, meeting national standards and the process requirement of "out-of-roundness of insulated cores ≤ 2.5% before cabling" in most companies' internal control standards. The second threshold, which translates to a maximum local outer diameter deviation of 3.82%, also meets national standards and can tolerate minor protrusions caused by slight die buildup and raw material impurities during the production process.

[0032] It should be noted that the first and second thresholds can also be adjusted according to different cable specifications, process requirements or testing standards, and no specific restrictions are made here.

[0033] Because the 3D STL model may generate multiple interconnected contours that are separate from each other during the actual slicing process, or there may be local noise contours or broken contours, directly fitting all intersection points may easily involve non-main contours in the calculation, leading to distortion of the roundness evaluation. Therefore, it is necessary to identify the connectivity of the slicing results.

[0034] In one possible implementation, S103 may include: S1036: Obtain the binarized image of the cable slice; The grayscale image of the cable slice is converted into a black-and-white binary image containing only the foreground (the cable entity) and the background (non-entity area), thus achieving preliminary separation of the cable from the background.

[0035] S1037: Traverse the image and extract all connected contours and corresponding connected regions; A connected component is a set of all adjacent pixels in an image that have the same pixel value. By traversing the binary image, all independent connected components are identified, and the outer contour line of each connected component is extracted.

[0036] For example, the Suzuki85 contour tracking algorithm (the default algorithm in OpenCV) can be used to traverse the binary image, retrieve all closed contours, establish the hierarchical structure of the contours, filter out the outer contours, and establish a corresponding connected region mask for each retained outer contour.

[0037] S1038: Determine the area of ​​each connected region, and take the outer contour of the connected region with the largest area as the target cross-sectional contour.

[0038] For example, Green's formula can be used to calculate its precise area, and the connected region with the largest area can be taken as the main area of ​​the cable.

[0039] For each cable slice, this application uses connected region analysis to extract the main connected contour with the largest area as the target cross-sectional contour. This can effectively suppress multi-contour interference and effectively eliminate various interferences such as surface burrs, minor defects, scanning noise, and background noise. Even if there are multiple small defects on the cable surface, the main contour can be accurately extracted. The extracted contour is a continuous closed curve without breaks or missing parts, which improves the stability and reliability of the circle fitting results.

[0040] It should be noted that the main connected contour with the most points can also be extracted as the target cross-sectional contour; the specific steps are not limited.

[0041] In one possible implementation, after extracting the maximum connected contour of the cable slice as the target cross-sectional contour, and before fitting the contour points on the target cross-sectional contour, S103 may further include: S1039: Determine the number of contour points on the target cross-sectional profile; S10310: If the quantity is less than the preset quantity, the target cross-sectional contour is determined to be invalid, and the step of fitting the contour points on the target cross-sectional contour is not executed; S10311: If the quantity is not less than the preset quantity, the target cross-sectional contour is determined to be valid, and the step of fitting the contour points on the target cross-sectional contour is executed.

[0042] When the number of contour points is below a critical value, least-squares circle fitting will exhibit severe numerical instability and a sharp drop in accuracy, and may even produce singular solutions. To avoid subsequent fitting errors that affect the accuracy of roundness detection, this application counts the number of valid points on the target cross-section contour, intercepts low-quality contours caused by incomplete slicing, contour breaks, large-area damage, scanning blind spots, etc., skips the circle fitting and roundness calculation steps for invalid contours, avoids invalid fitting from generating incorrect center and radius data, and ensures the reliability of roundness evaluation results from the source.

[0043] Furthermore, a curve showing the change of roundness index with axial position can be generated based on the roundness evaluation results of each cable slice. This curve can be used to locate abnormal sections and analyze the trend of roundness changes, and the results can be displayed.

[0044] For example, refer to Figure 2 The test results are output in a dual-view format: the left side displays the three-dimensional model of the cable and its layered coloring results, while the right side displays the curve of the roundness index changing with the axial position and the distribution of qualified / unqualified points.

[0045] The above method will be described in detail below with reference to specific embodiments.

[0046] A three-dimensional STL model was constructed and triangulated and cleaned up. The detection range was set to 250.0 mm to 350.0 mm along the cable axis, i.e., the Y-axis, and the slicing step size was set to 2.0 mm. A total of 51 cross sections to be analyzed were obtained.

[0047] For each cross section, the intersection of the 3D STL model with a slicing plane perpendicular to the Y-axis is performed, and the maximum connected contour in the cable slice is extracted as the target cross section contour. When the number of cross section contour points is not less than a preset number, the contour points are fitted with circles in the XZ plane to obtain the fitted circle center and fitted radius; further, the distance from each contour point to the fitted circle center is calculated to obtain the relative index of the radius difference between points p2p / r (%) and the relative index of the maximum deviation max_dev / r (%).

[0048] In this embodiment, the first threshold and the second threshold are set as follows: p2p / r ≤1.91%, max_dev / r ≤1.08%.

[0049] When both indicators meet the threshold requirements, the roundness of the current cross section is deemed acceptable; otherwise, it is deemed unacceptable.

[0050] Actual test results show that within the Y=250.0 mm~262.0 mm range, most cable sections meet the roundness requirements, for example: When Y=250.0 mm, p2p / r = 1.850% and max_dev / r = 1.066%, which is considered acceptable. When Y=252.0 mm, p2p / r = 1.837% and max_dev / r = 1.077%, which is considered acceptable. When Y=258.0 mm, p2p / r = 1.793% and max_dev / r = 1.052%, which is considered acceptable. When Y=262.0 mm, p2p / r = 1.807% and max_dev / r = 1.069%, which is considered acceptable.

[0051] As the axial position increases, some sections begin to show defects. For example: When Y=264.0 mm, p2p / r = 1.830% and max_dev / r = 1.084%. Since the maximum deviation relative index exceeds the threshold, it is judged as unqualified. When Y=270.0 mm, p2p / r = 1.867% and max_dev / r = 1.109%, which is considered unqualified. When Y=274.0 mm, p2p / r = 1.906% and max_dev / r = 1.115%, which is considered unqualified; When Y=276.0 mm, p2p / r = 1.926% and max_dev / r = 1.122%, which is considered unqualified; When Y=300.0 mm, p2p / r = 2.035% and max_dev / r = 1.150%, which is considered unqualified; When Y=318.0 mm, p2p / r = 2.249% and max_dev / r = 1.329%, which reaches the large deviation level in this embodiment and is judged as unqualified; When Y=350.0 mm, p2p / r = 2.056% and max_dev / r = 1.265%, which is considered unqualified.

[0052] The above statistical results show that the number of contour points for each cable slice is roughly stable between 1269 and 1282, indicating that the method of this application has good cross-sectional extraction stability during continuous slicing. Meanwhile, the test results clearly show that the roundness index does not remain constant along the axial direction, but rather exhibits a gradual increasing trend. This indicates that the method of this application can not only determine whether a single cable slice is qualified, but also identify the roundness variation pattern and abnormal section location along the axial direction of the cable, as detailed in Table 1.

[0053] Table 1 Roundness Test Results As shown in Table 1, the roundness detection method provided in this application can not only perform quantitative analysis of the roundness of continuous cross sections, but also effectively identify cross sections whose roundness is close to the critical threshold. For example, at Y=264.0mm, although p2p / r does not exceed the threshold, it is still correctly identified as an unqualified cross section because max_dev / r exceeds the limit. This shows that the dual threshold joint judgment mechanism provided in this application can effectively improve the ability to identify local out-of-roundness phenomena.

[0054] This application, based on a 3D STL model, eliminates the need for traditional contact measurement devices or single 2D cross-sectional images, making it suitable for geometric quality inspection in 3D scanning, digital twin, and smart manufacturing scenarios. Unlike traditional single-section or few discrete section inspection methods, this application obtains the continuous distribution pattern of roundness along the length direction through multi-position continuous slicing along the cable axis, thus providing a more comprehensive evaluation of the overall geometric quality of the cable. Addressing the potential issues of multiple connected contours, local fragment contours, and noise intersections in cable slicing results, this application proposes a maximum connected contour filtering mechanism, which can stably extract the main cable cross-section and improve the reliability of circle fitting and roundness calculation.

[0055] Secondly, this application also constructs a relative index for the difference in radius between points and a relative index for the maximum deviation, and adopts a dual-threshold joint judgment method, which improves the accuracy of identifying out-of-round features of complex cross-sections and can effectively avoid missed judgments caused by single-index evaluation. Moreover, since the evaluation indices all adopt a relative form related to the fitted radius, the influence of dimensional differences on the evaluation results can be effectively reduced, making the method of this application applicable to the roundness detection of cable products with different diameters and specifications.

[0056] Finally, the method of this application can not only determine whether a single slice is qualified, but also detect the gradual deterioration trend of roundness along the axial direction, providing a basis for production process analysis, defect location, and quality traceability. It can simultaneously output the cable's three-dimensional model display results and roundness variation curve, allowing inspection personnel to quickly identify unqualified sections and abnormal locations, which is beneficial for on-site analysis and subsequent process adjustments. The method provided in this application has good automation and engineering integration capabilities.

[0057] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0058] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0059] Figure 3 The diagram shows a schematic representation of a cable roundness detection device based on a three-dimensional model slice according to an embodiment of the present invention. For ease of explanation, only the parts relevant to the embodiment of the present invention are shown, and are described in detail below: like Figure 3 As shown, the cable roundness detection device based on 3D model slices includes: Model building module 21 is used to build a three-dimensional STL model of the cable to be tested; The slicing module 22 is used to slice the three-dimensional STL model of the cable along the cable axis to obtain multiple cable slices. Evaluation module 23 is used to extract the maximum connected contour of any cable slice as the target cross-sectional contour, and fit the contour points on the target cross-sectional contour to obtain the fitted circle center and fitted radius; determine the relative index of the radius difference between points and the relative index of the maximum deviation based on the fitted circle center and the fitted radius, and perform a dual threshold joint judgment based on the relative index of the radius difference between points and the relative index of the maximum deviation to determine the roundness evaluation result corresponding to the cable slice.

[0060] In one possible implementation, the evaluation module 23 may include: The distance calculation unit is used to determine the actual distance between each contour point on the target cross-section contour and the center of the fitted circle; The first index output unit is used to determine the relative index of the radius difference between points based on the fitted radius and each actual distance; The second index output unit is used to determine the maximum deviation relative index based on the fitting radius and each actual distance.

[0061] In one possible implementation, the first indicator output unit can be specifically used for: 1. Based on the fitted radius and each actual distance, the relative index of the radius difference between points is obtained by combining the first formula; The first formula may include: in, This is a relative index of the difference in radii between points. The fitting radius is... For the first The actual distance between each contour point and the center of the fitted circle.

[0062] In one possible implementation, the second indicator output unit can be specifically used for: 1. Based on the fitted radius and each actual distance, the maximum deviation relative index is obtained by combining the second formula; The second formula may include: in, This is the relative index of the maximum deviation.

[0063] In one possible implementation, the evaluation module 23 may include: The first evaluation output unit is used to determine that the roundness evaluation result of the cable slice is qualified if the relative index of the radius difference between points is not greater than the first threshold and the relative index of the maximum deviation is not greater than the second threshold. The second evaluation output unit is used to determine that the roundness evaluation result corresponding to the cable slice is unqualified if otherwise.

[0064] In one possible implementation, the first threshold can be 1.08% and the second threshold can be 1.91%.

[0065] In one possible implementation, the evaluation module 23 may include: A binarization unit is used to obtain a binarized image of the cable slice; The region traversal unit is used to traverse the image and extract all connected contours and corresponding connected regions. The maximum region selection unit is used to determine the area of ​​each connected region, and the outer contour of the connected region with the largest area is used as the target cross-sectional contour.

[0066] In one possible implementation, the evaluation module 23 may further include: The contour point quantity determination unit is used to determine the number of contour points on the target cross-sectional contour. The first contour filtering unit is used to determine that the target cross-sectional contour is invalid if the number is less than the preset number, and does not perform the step of fitting the contour points on the target cross-sectional contour. The second contour filtering unit is used to determine that the target cross-sectional contour is valid if the number is not less than a preset number, and to perform the step of fitting the contour points on the target cross-sectional contour.

[0067] Figure 4 This is a schematic diagram of the electronic device 3 provided in an embodiment of the present invention. Figure 4 As shown, the electronic device 3 of this embodiment includes a processor 30 and a memory 31. The memory 31 stores a computer program 32. When the processor 30 executes the computer program 32, it implements the steps in the various method embodiments described above. Alternatively, when the processor 30 executes the computer program 32, it implements the functions of each module / unit in the various device embodiments described above.

[0068] For example, computer program 32 may be divided into one or more modules / units, which are stored in memory 31 and executed by processor 30 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 32 in electronic device 3.

[0069] Electronic device 3 may include, but is not limited to, processor 30 and memory 31. Those skilled in the art will understand that... Figure 4 This is merely an example of electronic device 3 and does not constitute a limitation on electronic device 3. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 3 may also include input / output devices, network access devices, buses, etc.

[0070] For the sake of simplicity and clarity, only the above-described functional modules / units are used as examples. In practical applications, the functions described above can be assigned to different functional modules / units as needed. These modules / units can be implemented in hardware, software, or a combination of both.

[0071] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for detecting cable roundness based on 3D model slicing, characterized in that, include: Construct a 3D STL model of the cable to be tested; The three-dimensional STL model of the cable is sliced ​​along the cable axis to obtain multiple cable slices; For any cable slice, the maximum connected contour of the cable slice is extracted as the target cross-sectional contour, and the contour points on the target cross-sectional contour are fitted to obtain the fitted circle center and the fitted radius. Based on the fitted circle center and the fitted radius, the relative index of the radius difference between points and the relative index of the maximum deviation are determined, and a dual threshold joint judgment is performed based on the relative index of the radius difference between points and the relative index of the maximum deviation to determine the roundness evaluation result corresponding to the cable slice.

2. The cable roundness detection method based on three-dimensional model slicing according to claim 1, characterized in that, The step of determining the relative index of the radius difference between points and the relative index of the maximum deviation based on the fitted circle center and the fitted radius includes: Determine the actual distance between each contour point on the target cross-section contour and the center of the fitted circle; Based on the fitted radius and each actual distance, determine the relative index of the radius difference between points; The maximum deviation relative index is determined based on the fitted radius and each actual distance.

3. The cable roundness detection method based on three-dimensional model slicing according to claim 2, characterized in that, The step of determining the relative index of the radius difference between points based on the fitted radius and each actual distance includes: Based on the fitted radius and each actual distance, the relative index of the radius difference between points is obtained by combining the first formula; The first formula includes: in, This refers to the relative index of the radius difference between the points. The fitting radius is... For the first The actual distance between each contour point and the center of the fitted circle.

4. The cable roundness detection method based on three-dimensional model slicing according to claim 3, characterized in that, The step of determining the maximum deviation relative index based on the fitted radius and each actual distance includes: Based on the fitted radius and each actual distance, the maximum deviation relative index is obtained by combining the second formula; The second formula includes: in, This is the relative index of the maximum deviation.

5. The cable roundness detection method based on three-dimensional model slicing according to any one of claims 1 to 4, characterized in that, The step of determining the roundness evaluation result of the cable slice by performing a dual-threshold joint judgment based on the relative index of the inter-point radius difference and the relative index of the maximum deviation includes: If the relative index of the radius difference between points is not greater than the first threshold and the relative index of the maximum deviation is not greater than the second threshold, then the roundness evaluation result corresponding to the cable slice is determined to be qualified. Otherwise, the roundness evaluation result corresponding to the cable slice is determined to be unqualified.

6. The cable roundness detection method based on three-dimensional model slicing according to claim 5, characterized in that, The first threshold is 1.08%, and the second threshold is 1.91%.

7. The cable roundness detection method based on three-dimensional model slicing according to any one of claims 1 to 4, characterized in that, Extracting the maximum connected contour of the cable slice as the target cross-sectional contour includes: Obtain the binarized image of the cable slice; Traverse the image and extract all connected contours and their corresponding connected regions; Determine the area of ​​each connected region, and take the outer contour of the connected region with the largest area as the target cross-sectional contour.

8. The cable roundness detection method based on three-dimensional model slicing according to any one of claims 1 to 4, characterized in that, After extracting the maximum connected contour of the cable slice as the target cross-sectional contour, and before fitting the contour points on the target cross-sectional contour, the method further includes: Determine the number of contour points on the target cross-sectional profile; If the number is less than the preset number, the target cross-sectional contour is determined to be invalid, and the step of fitting the contour points on the target cross-sectional contour is not performed; If the number is not less than the preset number, then the target cross-sectional contour is determined to be valid, and the step of fitting the contour points on the target cross-sectional contour is performed.

9. A cable roundness detection device based on three-dimensional model slicing, characterized in that, include: The model building module is used to build a 3D STL model of the cable to be tested. The slicing module is used to slice the three-dimensional STL model of the cable along the cable axis to obtain multiple cable slices; The evaluation module is used to extract the maximum connected contour of any cable slice as the target cross-sectional contour, and fit the contour points on the target cross-sectional contour to obtain the fitting circle center and fitting radius; determine the relative index of the radius difference between points and the relative index of the maximum deviation based on the fitting circle center and the fitting radius; and perform a dual threshold joint judgment based on the relative index of the radius difference between points and the relative index of the maximum deviation to determine the roundness evaluation result corresponding to the cable slice.

10. An electronic device, characterized in that, The device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the cable roundness detection method based on three-dimensional model slicing as described in any one of claims 1 to 8.

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