Aperture detection method and device of cooling hole, electronic equipment and storage medium

Abstract

The invention relates to a cooling hole diameter detection method and device, electronic equipment and a storage medium. The method for detecting the aperture of the cooling hole comprises the steps that a focusing image sequence of a to-be-detected cooling hole is acquired, and the focusing image sequence is a two-dimensional image set obtained by scanning the to-be-detected cooling hole at equal intervals in the axial direction; generating a panoramic depth image of the to-be-detected cooling hole according to the focusing image sequence, wherein the panoramic depth image is a clear image of each part of the to-be-detected cooling hole; and determining the aperture of the to-be-measured cooling hole according to the sub-pixel-level edge of the target area corresponding to the to-be-measured cooling hole on the panoramic depth image and the calibrated pixel size equivalent. The reliability and accuracy of cooling hole diameter detection can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of machine vision and image processing, and in particular to a method, device, electronic device and storage medium for detecting the aperture of a cooling hole. Background Art

[0002] In the design and development of the new generation of aircraft engines, in order to further improve the temperature tolerance of hot-end components such as turbine blades, in addition to the use of high-temperature resistant alloy materials and special heat treatment processes, a large number of film cooling holes with complex geometric structures and discrete and dense distribution (hereinafter referred to as: cooling holes) are also used in the structural design of the blades.

[0003] At the production site, operators usually use plug gauges to detect whether the diameter of the cooling hole meets the quality control requirements, and determine the actual value of the diameter by selecting plug gauges of different sizes for approximation. However, due to the limitations of the processing technology, the circularity of the cooling hole is poor and the accuracy is unstable. The diameter measured by the plug gauge is often smaller than the actual diameter of the cooling hole, and only qualitative judgment can be made, and accurate detection cannot be achieved.

[0004] In recent years, with the development of advanced optical detection technology, non-contact detection methods based on machine vision and image processing have been widely used in aerospace and other fields, solving many problems that are difficult or impossible to solve with traditional detection methods. When applying machine vision technology to the detection of turbine blade cooling holes, on the one hand, since the aperture of the cooling holes is small and distributed on the blade surface, the hole wall and the blade surface intersect to form an irregular space closed curve; on the other hand, the depth of field of the image acquisition device used to obtain the cooling hole image is small, so it is impossible to obtain a very clear cooling hole image of each part through only one imaging. This brings great difficulties to the subsequent image processing and aperture solution, and even makes the detection process impossible, and the reliability and accuracy of the cooling hole aperture detection are not high. Summary of the invention

[0005] (1) Technical issues to be solved

[0006] The present application provides a cooling hole diameter detection method, device, electronic device and storage medium to solve the problem of low reliability and accuracy of cooling hole diameter detection in the prior art.

[0007] (2) Technical solution

[0008] In a first aspect, the present application provides a method for detecting the diameter of a cooling hole, comprising:

[0009] Acquire a focused image sequence of the cooling hole to be tested, wherein the focused image sequence is a set of two-dimensional images obtained by scanning the cooling hole to be tested at equal intervals along the axial direction;

[0010] Generate a full-view depth image of the cooling hole to be tested according to the focused image sequence, wherein the full-view depth image is an image in which all parts of the cooling hole to be tested are clear;

[0011] The aperture of the cooling hole to be tested is determined according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent.

[0012] Furthermore, before acquiring the focused image sequence of the cooling hole to be tested, the method further includes:

[0013] The step length, moving range and starting position of the cooling hole to be tested for equidistant scanning along the axial direction are determined.

[0014] Further, generating a panoramic depth image of the cooling hole to be tested according to the focused image sequence includes:

[0015] Extracting pixels of the clearest part of each image in the focused image sequence using a set pixel clarity evaluation algorithm and a prescribed focus measurement;

[0016] By using the set overlapping and stitching rules, the pixels of the clearest part of each image are fused according to the original image position to generate a full-view depth image of the cooling hole to be tested.

[0017] Furthermore, before determining the aperture of the cooling hole to be tested according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent, the method further includes:

[0018] Denoising the panoramic depth image, and dividing the denoised panoramic depth image into a foreground area and a background area according to a preset grayscale threshold;

[0019] The foreground area is divided into a plurality of mutually unconnected sub-areas, and a target area is determined in each sub-area according to an area parameter and a circularity parameter of each sub-area.

[0020] Furthermore, the denoising of the panoramic depth image, dividing the denoised panoramic depth image into a foreground area and a background area according to a preset grayscale threshold, includes:

[0021] Using a mean filtering algorithm to smooth the panoramic depth image to reduce noise in the panoramic depth image;

[0022] The area in the denoised full depth image with a grayscale value less than or equal to a preset grayscale threshold is taken as a foreground area, and the area with a grayscale value greater than the preset grayscale threshold is taken as a background area.

[0023] Furthermore, dividing the foreground area into a plurality of mutually unconnected sub-areas and determining the target area in each sub-area according to the area parameter and circularity parameter of each sub-area includes:

[0024] Using a circular structure element with a preset radius to perform a morphological opening operation on the foreground area, so as to divide the foreground area into a plurality of sub-areas that are not connected to each other;

[0025] The area parameter and circularity parameter of each sub-region are determined, and the sub-region with the largest circularity parameter among the sub-regions whose area parameters are greater than or equal to the preset area is determined as the target region.

[0026] Further, determining the aperture of the cooling hole to be tested according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent includes:

[0027] Extracting the sub-pixel edge of the target area, and performing least squares circle fitting on the sub-pixel edge to obtain a fitting circle radius;

[0028] The radius of the fitting circle is multiplied by the calibrated pixel size equivalent to obtain the aperture of the cooling hole to be measured.

[0029] In a second aspect, the present application provides a cooling hole aperture detection device, including a cooling hole five-axis visual coordinate measurement device and a host computer; the cooling hole five-axis visual coordinate measurement device includes a base assembly, a two-axis rotary motion assembly, a three-axis linear motion assembly, an image acquisition assembly, and a fixture assembly;

[0030] The three-axis linear motion component is installed on the base component, and the image acquisition component is installed on the three-axis linear motion component; the two-axis rotary motion component is installed on the base component, and the fixture component is installed on the two-axis rotary motion component;

[0031] The fixture assembly is used to clamp the turbine blade, the two-axis rotary motion assembly is used to drive the turbine blade to rotate, the three-axis linear motion assembly is used to drive the image acquisition assembly to move linearly, and the image acquisition assembly is used to scan the cooling holes to be measured on the turbine blade at equal intervals along the axial direction;

[0032] The host computer is connected to the cooling hole five-axis visual coordinate measuring device; the host computer is used to implement the aperture detection method of the cooling hole as described above.

[0033] In a third aspect, the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the aperture detection method for cooling holes as described above when executing the computer program.

[0034] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the aperture detection method of the cooling hole as described above is implemented.

[0035] (3) Beneficial effects

[0036] The above technical solution of the present application has the following advantages:

[0037] The first aspect of the present application provides a method for detecting the aperture of cooling holes, which uses a non-contact aperture detection method based on machine vision and image processing. Compared with the traditional manual detection method using a stop-gage gauge, the method has the advantages of high efficiency, accurate measurement, low labor intensity and easy automation. The aperture detection of the cooling hole to be tested is performed based on the panoramic depth image reconstructed and synthesized from the focused image sequence, which reduces the difficulty of subsequent image processing, and has the advantages of high reliability, strong robustness and anti-interference ability, and high aperture detection accuracy. Finally, the aperture of the cooling hole to be tested is determined based on the sub-pixel edge and the calibrated pixel size equivalent, which improves the reliability and accuracy of the cooling hole aperture detection.

[0038] It can be understood that the beneficial effects of the second, third and fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 A schematic diagram of the flow chart of the cooling hole diameter detection method provided in the present application;

[0041] Figure 2 A schematic diagram of the structure of the turbine blade and the cooling holes thereon provided in this application;

[0042] Figure 3 A schematic diagram of the structure of the five-axis visual coordinate measurement device for cooling holes provided in this application;

[0043] Figure 4 A schematic diagram of the acquisition process of the focus image sequence provided in this application;

[0044] Figure 5 The overall flow chart of the cooling hole diameter detection method provided in the present application;

[0045] Figure 6 Full depth image of cooling holes provided for this application;

[0046] Figure 7 The extraction result map of the target area provided for this application;

[0047] Figure 8 This is the sub-pixel edge extraction and aperture fitting result diagram provided by this application;

[0048] Fig. 9 A schematic diagram of the structure of the electronic device provided in this application.

[0049] Figure numerals: 1. turbine blade; 11. cooling hole; 2. five-axis visual coordinate measuring device for cooling hole; 21. base assembly; 22. two-axis rotary motion assembly; 23. three-axis linear motion assembly; 24. image acquisition assembly; 241. imaging optical axis; 25. fixture assembly; 3. focused image sequence; 4. full depth of field image; 5. target area; 6. sub-pixel edge; 7. fitting circle. DETAILED DESCRIPTION

[0050] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0051] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0052] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0053] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. "Multiple" means "two or more".

[0054] In order to solve the problems existing in the prior art, the present application provides an aperture detection method for cooling holes. First, a focused image sequence of the cooling hole to be tested is collected along the axial direction of the cooling hole, and reconstructed and synthesized into a full-depth image. Then, the image is subjected to target area selection, sub-pixel edge extraction, aperture solution and other steps to obtain the physical aperture of the cooling hole to be tested, which makes up for the problems of low resolution of a single image, missing effective information, and distorted solution, and improves the reliability and accuracy of the cooling hole aperture solution.

[0055] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application.

[0056] like Figure 1 As shown, an embodiment of the present application provides a method for detecting the diameter of a cooling hole, comprising:

[0057] Acquire a focused image sequence of the cooling hole to be tested, wherein the focused image sequence is a set of two-dimensional images obtained by scanning the cooling hole to be tested at equal intervals along the axial direction;

[0058] Generate a full-view depth image of the cooling hole to be tested according to the focused image sequence, wherein the full-view depth image is an image in which all parts of the cooling hole to be tested are clear;

[0059] The aperture of the cooling hole to be tested is determined according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent.

[0060] The present application uses an image acquisition component to capture a focused image sequence along the axial direction of the cooling hole to be tested, and reconstructs and synthesizes a full-view depth image with very clear parts, which is applied to subsequent image processing, thereby improving the reliability and accuracy of image processing and aperture solution.

[0061] The area screening condition of the sub-region is set according to the theoretical aperture of the cooling hole to be tested and the calibrated pixel size equivalent, and the regional area parameter and the regional circularity parameter are set as double screening conditions, so as to accurately and uniquely select the cooling hole area as the target area.

[0062] The non-contact aperture detection method based on machine vision and image processing has the advantages of high efficiency, accurate measurement, low labor intensity and easy automation compared to the traditional manual detection method using a stop-gap plug gauge.

[0063] Since the full-view depth image that can fully and truly reflect the overall surface of the small hole to be tested is used to analyze the actual aperture of the cooling hole to be tested, the difficulty of subsequent image processing is reduced, and it has the advantages of high reliability, strong robustness and anti-interference ability, and high aperture detection accuracy.

[0064] In some embodiments, before acquiring the focused image sequence of the cooling hole to be tested, the method further includes:

[0065] The step length, moving range and starting position of the cooling hole to be tested for equidistant scanning along the axial direction are determined.

[0066] In some embodiments, generating a panoramic depth image of the cooling hole to be tested according to the focused image sequence includes:

[0067] Extracting pixels of the clearest part of each image in the focused image sequence using a set pixel clarity evaluation algorithm and a prescribed focus measurement;

[0068] By using the set overlapping and stitching rules, the pixels of the clearest part of each image are fused according to the original image position to generate a full-view depth image of the cooling hole to be tested.

[0069] In some embodiments, before determining the aperture of the cooling hole to be tested according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent, the method further includes:

[0070] Denoising the panoramic depth image, and dividing the denoised panoramic depth image into a foreground area and a background area according to a preset grayscale threshold;

[0071] The foreground area is divided into a plurality of mutually unconnected sub-areas, and a target area is determined in each sub-area according to an area parameter and a circularity parameter of each sub-area.

[0072] In some embodiments, the denoising of the panoramic depth image, dividing the denoised panoramic depth image into a foreground area and a background area according to a preset grayscale threshold, includes:

[0073] Using a mean filtering algorithm to smooth the panoramic depth image to reduce noise in the panoramic depth image;

[0074] The area in the denoised full depth image with a grayscale value less than or equal to a preset grayscale threshold is taken as a foreground area, and the area with a grayscale value greater than the preset grayscale threshold is taken as a background area.

[0075] In some embodiments, dividing the foreground area into a plurality of mutually unconnected sub-areas and determining the target area in each sub-area according to an area parameter and a circularity parameter of each sub-area includes:

[0076] Using a circular structure element with a preset radius to perform a morphological opening operation on the foreground area, so as to divide the foreground area into a plurality of sub-areas that are not connected to each other;

[0077] The area parameter and circularity parameter of each sub-region are determined, and the sub-region with the largest circularity parameter among the sub-regions whose area parameters are greater than or equal to the preset area is determined as the target region.

[0078] In some embodiments, determining the aperture of the cooling hole to be tested according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent includes:

[0079] Extracting the sub-pixel edge of the target area, and performing least squares circle fitting on the sub-pixel edge to obtain a fitting circle radius;

[0080] The radius of the fitting circle is multiplied by the calibrated pixel size equivalent to obtain the aperture of the cooling hole to be measured.

[0081] The purpose of this application is to provide a method for accurately obtaining Figure 2 The method for measuring the physical aperture of the cooling hole 11 on the turbine blade 1 is shown. The method is implemented based on a five-axis visual coordinate measuring device for the cooling hole. Figure 3 As shown, the cooling hole five-axis visual coordinate measuring device 2 includes a base assembly 21, a two-axis rotary motion assembly 22, a three-axis linear motion assembly 23, an image acquisition assembly 24, and a fixture assembly 25.

[0082] The five-axis visual coordinate measuring device 2 for cooling holes has three linear motion axes X, Y, and Z and two rotary motion axes B and C, which can realize single-axis motion and multi-axis linkage; the three linear motion axes X, Y, and Z are perpendicular to each other and integrated together, which are realized by a three-axis linear motion assembly 23; the two rotary motion axes B and C are perpendicular to each other and integrated together, the direction of the B axis is parallel to the direction of the Y axis, and the direction of the C axis is parallel to the direction of the Z axis, which are realized by a two-axis rotary motion assembly 22, the angle rotation range of the B axis is -90° to +90°, and the angle rotation range of the C axis is 0° to 360°.

[0083] The image acquisition component 24 is installed on the Z-axis end of the three-axis linear motion component 23, with an optical magnification of 5× to 10× and a depth of field range of ≤0.20 mm. Figure 4 As shown, the imaging optical axis 241 of the image acquisition component 24 is made parallel to the Z-axis direction of the three-axis linear motion component 23 through mechanical adjustment.

[0084] like Figure 5 As shown, the method is implemented through the following specific steps:

[0085] Step 1: Clamp the turbine blade. After cleaning and drying the turbine blade 1 , place it in the fixture assembly 25 , and then use a micrometer or the like to mechanically adjust and align the positioning reference on the turbine blade 1 , and then clamp it, so that the turbine blade 1 is correctly positioned in the fixture assembly 25 .

[0086] Step 2: Plan the detection path. Import the digital model of the turbine blade 1 into the host computer software, pick up all the cooling holes 11 that need to be measured in aperture in turn, plan the detection path, and then set the step length, moving range and starting position along the Z axis direction when applying the image acquisition component 24 to obtain the focused image sequence 3 of the cooling hole 11 to be tested in the host computer software according to the axial depth of the cooling hole 11 to be tested and the depth of field of the image acquisition component 24, so that the moving range is greater than the axial depth of the cooling hole 11 to be tested, and the step length is smaller than the depth of field of the image acquisition component 24.

[0087] Step three, collect the focused image sequence. According to the planned detection path, on the one hand, control the two-axis rotary motion component 22 to drive the turbine blade 1 to rotate, so that the orifice of the cooling hole 11 to be tested faces the positive direction of the Z axis, and further make the axial direction of the cooling hole 11 to be tested parallel to the Z axis direction; on the other hand, control the three-axis linear motion component 23 to drive the image acquisition component 24 to move, so that it is aligned with the cooling hole 11 to be tested and moves to the starting position. At this time, the cooling hole 11 to be tested completely enters the field of view of the image acquisition component 24 and is in the central position of the field of view. Then control the three-axis linear motion component 23 to drive the image acquisition component 24 to move at equal intervals from the starting position along the Z axis direction according to the set step size and moving range, and synchronously collect the two-dimensional image of the cooling hole 11 to be tested, thereby completing the axial equal-interval scanning of the cooling hole 11 to be tested and obtaining a series of two-dimensional images. The collection of these two-dimensional images is called a focused image sequence 3.

[0088] Step 4: Synthesize a full-depth image. Each image in the focused image sequence 3 is processed by the digital image processing and analysis module in the host computer software, and the pixels of each image with clear imaging are extracted using the set pixel clarity evaluation algorithm and the specified focus measurement. Then, the clear pixels in each image are merged into a new image according to their positions in the original image through the set superposition and splicing rules, thereby reconstructing and synthesizing a new image of the cooling hole 11 to be tested with all parts being very clear and sharp, which is the full-depth image 4, as shown in FIG. Figure 6 shown.

[0089] Step 5: Threshold segmentation. The panoramic depth image 4 is smoothed using a mean filter algorithm to reduce image noise. A grayscale threshold T is set to segment the denoised panoramic depth image 4 into a foreground area and a background area. The area composed of pixels with grayscale values ​​less than or equal to T is the foreground area, and the area composed of pixels with grayscale values ​​greater than T is the background area.

[0090] Step 6: Morphological opening operation. According to the threshold segmentation result, use a radius of R p The foreground area is subjected to morphological opening operation by a circular structural element (unit: pixel), which interrupts some thinner and narrower connected parts in the foreground area, so as to further divide the foreground area into multiple unconnected and independent sub-areas.

[0091] Step 7: Target area selection. Calculate the area (number of pixels contained in the sub-area) and circularity (degree of closeness to the ideal circle) parameters of each sub-area. First, select the sub-areas with area ≥ A, and then set the sub-area corresponding to the maximum circularity as target area 5, that is, the cooling hole area. Figure 7 shown.

[0092]

[0093] Wherein, D is the theoretical aperture of the cooling hole 11 to be tested, unit: mm; K is the calibrated pixel size equivalent of the image acquisition component 24, unit: mm / pixel; a is the proportional coefficient, and the value range is 0.7 to 0.9.

[0094] Step 8: Sub-pixel edge extraction: The sub-pixel edge 6 of the target area 5 is extracted by a sub-pixel edge detection operator.

[0095] Step 9: Aperture calculation. Figure 8 As shown, the sub-pixel edge 6 is fitted by least squares circle to obtain the radius R (unit: pixel) of the fitting circle 7, and then multiplied by the pixel size equivalent K to obtain the physical diameter (aperture) Φ of the cooling hole 11 to be measured.

[0096] Φ=2·R·K

[0097] The aperture detection method for cooling holes provided in the embodiments of the present application can accurately calculate the physical aperture of the cooling hole from the focused image sequence of the cooling hole, and is implemented based on the panoramic depth image reconstructed and synthesized from the focused image sequence. The method includes the steps of clamping the turbine blades, planning the detection path, collecting the focused image sequence, synthesizing the panoramic depth image, threshold segmentation, morphological opening operation, target area selection, sub-pixel edge extraction and aperture solution. The present application provides key technical solutions and solutions for machine vision detection of the aperture of turbine blade cooling holes, which helps to improve the reliability and accuracy of cooling hole aperture detection and has great practical application value.

[0098] The present application also provides a cooling hole diameter detection device, including a cooling hole five-axis visual coordinate measurement device and a host computer. Figure 3 As shown, the cooling hole five-axis visual coordinate measuring device 2 includes a base assembly 21, a two-axis rotary motion assembly 22, a three-axis linear motion assembly 23, an image acquisition assembly 24, and a fixture assembly 25;

[0099] The three-axis linear motion component 23 is installed on the base component 21, and the image acquisition component 24 is installed on the three-axis linear motion component 23; the two-axis rotary motion component 22 is installed on the base component 21, and the fixture component 25 is installed on the two-axis rotary motion component 22;

[0100] The clamp assembly 25 is used to clamp Figure 2 In the turbine blade 1 shown, the two-axis rotary motion assembly 22 is used to drive the turbine blade 1 to rotate, the three-axis linear motion assembly 23 is used to drive the image acquisition assembly 24 to move linearly, and the image acquisition assembly 24 is used to scan the cooling holes 11 to be tested on the turbine blade 1 at equal intervals along the axial direction;

[0101] The host computer is connected to the cooling hole five-axis visual coordinate measuring device 2; the host computer is used to implement the aperture detection method of the cooling hole as described above.

[0102] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

[0103] The present application embodiment also provides an electronic device 900, such as Fig. 9 As shown, it includes a memory 901, a processor 902, and a computer program 903 stored in the memory 901 and executable on the processor 902. When the processor 902 executes the computer program 903, the steps of the aperture detection method for the cooling hole provided in the first aspect are implemented.

[0104] In applications, the electronic device may include, but is not limited to, a processor and a memory. Fig. 9 This is only an example of an electronic device and does not constitute a limitation on the electronic device. It may include more or fewer components than shown in the figure, or combine certain components, or different components, such as input and output devices, network access devices, etc. Input and output devices may include cameras, audio acquisition / playback devices, display screens, etc. Network access devices may include a network module for wirelessly communicating with external devices.

[0105] In applications, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0106] In application, the memory may be an internal storage unit of an electronic device in some embodiments, such as a hard disk or memory of the electronic device. The memory may also be an external storage device of the electronic device in other embodiments, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device. The memory may also include both an internal storage unit and an external storage device of the electronic device. The memory is used to store operating systems, applications, boot loaders (BootLoader), data, and other programs, such as program codes of computer programs, etc. The memory may also be used to temporarily store data that has been output or is to be output.

[0107] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0108] The present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of each of the above-mentioned method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device that can carry the computer program code to an electronic device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a disk or an optical disk.

[0109] Those of ordinary skill in the art will appreciate that the devices and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0110] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices, which can be electrical, mechanical or other forms.

[0111] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for detecting the diameter of a cooling hole, characterized in that: include: Acquire a focused image sequence of the cooling hole to be tested, wherein the focused image sequence is a set of two-dimensional images obtained by scanning the cooling hole to be tested at equal intervals along the axial direction; Generate a full-view depth image of the cooling hole to be tested according to the focused image sequence, wherein the full-view depth image is an image in which all parts of the cooling hole to be tested are clear; The aperture of the cooling hole to be tested is determined according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent.

2. The cooling hole diameter detection method according to claim 1, characterized in that: Before acquiring the focused image sequence of the cooling hole to be tested, the method further includes: The step length, moving range and starting position of the cooling hole to be tested for equidistant scanning along the axial direction are determined.

3. The cooling hole diameter detection method according to claim 1, characterized in that: Generating a panoramic depth image of the cooling hole to be tested according to the focused image sequence includes: Extracting pixels of the clearest part of each image in the focused image sequence using a set pixel clarity evaluation algorithm and a prescribed focus measurement; By using the set overlapping and stitching rules, the pixels of the clearest part of each image are fused according to the original image position to generate a full-view depth image of the cooling hole to be tested.

4. The cooling hole diameter detection method according to claim 1, characterized in that: Before determining the aperture of the cooling hole to be tested according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent, the method further includes: Denoising the panoramic depth image, and dividing the denoised panoramic depth image into a foreground area and a background area according to a preset grayscale threshold; The foreground area is divided into a plurality of mutually unconnected sub-areas, and a target area is determined in each sub-area according to an area parameter and a circularity parameter of each sub-area.

5. The cooling hole diameter detection method according to claim 4, characterized in that: The step of reducing noise on the panoramic depth image and dividing the panoramic depth image after noise reduction into a foreground area and a background area according to a preset grayscale threshold comprises: Using a mean filtering algorithm to smooth the panoramic depth image to reduce noise in the panoramic depth image; The area in the denoised full depth image with a grayscale value less than or equal to a preset grayscale threshold is taken as a foreground area, and the area with a grayscale value greater than the preset grayscale threshold is taken as a background area.

6. The cooling hole diameter detection method according to claim 4, characterized in that: The foreground area is divided into a plurality of mutually unconnected sub-areas, and a target area is determined in each sub-area according to an area parameter and a circularity parameter of each sub-area, including: Using a circular structure element with a preset radius to perform a morphological opening operation on the foreground area, so as to divide the foreground area into a plurality of sub-areas that are not connected to each other; The area parameter and circularity parameter of each sub-region are determined, and the sub-region with the largest circularity parameter among the sub-regions whose area parameters are greater than or equal to the preset area is determined as the target region.

7. The cooling hole diameter detection method according to claim 1, characterized in that: The determining the aperture of the cooling hole to be tested according to the sub-pixel edge of the target area corresponding to the cooling hole to be tested on the panoramic depth image and the calibrated pixel size equivalent comprises: Extracting the sub-pixel edge of the target area, and performing least squares circle fitting on the sub-pixel edge to obtain a fitting circle radius; The radius of the fitting circle is multiplied by the calibrated pixel size equivalent to obtain the aperture of the cooling hole to be measured.

8. A cooling hole diameter detection device, characterized in that: It includes a five-axis visual coordinate measuring device for cooling holes and a host computer; the five-axis visual coordinate measuring device for cooling holes includes a base assembly, a two-axis rotary motion assembly, a three-axis linear motion assembly, an image acquisition assembly, and a fixture assembly; The three-axis linear motion component is installed on the base component, and the image acquisition component is installed on the three-axis linear motion component; the two-axis rotary motion component is installed on the base component, and the fixture component is installed on the two-axis rotary motion component; The fixture assembly is used to clamp the turbine blade, the two-axis rotary motion assembly is used to drive the turbine blade to rotate, the three-axis linear motion assembly is used to drive the image acquisition assembly to move linearly, and the image acquisition assembly is used to scan the cooling holes to be measured on the turbine blade at equal intervals along the axial direction; The host computer is connected to the cooling hole five-axis visual coordinate measuring device; the host computer is used to implement the cooling hole aperture detection method according to any one of claims 1 to 7.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the cooling hole diameter detection method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for detecting the diameter of the cooling hole according to any one of claims 1 to 7 is implemented.

Images