Method and device for detecting geometric parameters of end face of optical fiber bundle

Abstract

The invention relates to the field of optical detection instruments, and discloses a method and device for detecting geometric parameters of an optical fiber bundle end face, and the method comprises the steps: controlling light emitted by a light source to obliquely enter a to-be-detected optical fiber bundle at a preset angle and optimal illuminance; performing convolution operation on pixel points at different pixel positions in the end face image of the to-be-detected optical fiber bundle by adopting different convolution kernels to generate a gradient map; extracting an edge image of the gradient map, and performing ellipse fitting and circle fitting to obtain an ellipse parameter and a circle parameter corresponding to the fitted image; and geometric parameters of the to-be-detected optical fiber bundle are calculated. According to the method, a common illumination light source is adopted and obliquely irradiates the cladding and the surface of the coating layer, so that geometric parameter detection can be carried out on the optical fiber with the coating layer and the cladding layer, and meanwhile, specific convolution parameters, light source brightness, an oblique incidence angle adjusting method and the like in an image edge extraction algorithm are optimized; the device can adapt to optical fiber bundles with different lengths and different transmittances, and the detection efficiency and accuracy are improved.

Description

Technical Field

[0001] The present invention relates to the field of optical detection instruments, and in particular to a method and device for detecting geometric parameters of an optical fiber bundle end face. Background Art

[0002] Optical fiber is widely used in communications, healthcare, and other fields due to its high-quality light-guiding properties. Laser transmission is particularly common in optical fiber bundles. As a precision transmission medium, optical fiber bundles are subject to defects such as dust, dirt, scratches, damage, and poor polishing on their end faces, which can severely impact light transmission efficiency and signal integrity. Therefore, during the production process, the condition of the optical fiber bundle end faces must be rigorously inspected, including precise measurement of their geometric parameters, to optimize the effectiveness of optical fiber applications.

[0003] Many methods for detecting optical fiber geometric parameters have been proposed, such as manual interpretation methods. This involves inserting the fiber bundle to be tested into an adapter, and then allowing the operator to directly observe the end-face image of the fiber bundle through an eyepiece to calculate the optical fiber geometric parameters. This method results in highly subjective detection results, low detection accuracy, and can easily cause eye fatigue for the operator. In addition, there are computer vision processing methods that primarily focus on optical fiber transmission imaging. This method, based on an image edge extraction algorithm, segments the optical fiber end-face image into different parts, then calculates the optical fiber geometric parameters by fitting a circle using methods such as the least squares method. This method places high demands on the imaging quality of the optical fiber end-face image and the image processing process, and can easily lead to inaccurate measurement results for optical fiber geometric parameters, especially coating layer geometric parameters. Summary of the Invention

[0004] The present invention provides a method and device for detecting geometric parameters of an optical fiber bundle end face, which solves the above-mentioned technical problems.

[0005] A first aspect of an embodiment of the present invention provides a method for detecting geometric parameters of an optical fiber bundle end face, comprising the following steps:

[0006] Step 1: Adjust the illumination angle and current illumination of the light source and obtain a first end face image of the optical fiber bundle to be inspected, wherein the light emitted by the light source is obliquely incident on the optical fiber bundle to be inspected at a preset angle and optimal illumination;

[0007] Step 2: preprocessing the first end face image to generate a second end face image;

[0008] Step 3: performing convolution operations on pixels at different pixel positions in the second end face image using different convolution kernels, and taking the absolute value of the convolution results pixel by pixel to generate a gradient map of the second end face image;

[0009] Step 4, performing edge extraction on the gradient image, and performing ellipse fitting and circle fitting on the extracted edge image using a preset ellipse fitting method and a preset circle fitting method, respectively, to obtain ellipse parameters and circle parameters corresponding to the fitted image;

[0010] Step 5: Calculate the geometric parameters of the optical fiber bundle to be tested based on the ellipse parameters and the circle parameters.

[0011] A second aspect of the embodiments of the present invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the above-mentioned method for detecting geometric parameters of an end face of an optical fiber bundle is implemented.

[0012] A third aspect of an embodiment of the present invention provides a device for detecting the geometric parameters of an optical fiber bundle end face, comprising a computer-readable storage medium and a processor, wherein the processor implements the steps of the above-mentioned method for detecting the geometric parameters of an optical fiber bundle end face when executing a computer program on the computer-readable storage medium.

[0013] A fourth aspect of the embodiments of the present invention provides a device for detecting geometric parameters of an optical fiber bundle end face, comprising a light source, a lens group, an image acquisition unit, an image processing unit, and a clamping assembly for clamping the optical fiber bundle to be detected.

[0014] The light source is obliquely arranged above the optical fiber bundle to be detected, and the light emitted by the light source is obliquely incident on the optical fiber bundle to be detected at a preset angle, and enters the lens group after diffuse reflection by the cladding and coating layer of the optical fiber bundle to be detected;

[0015] The image acquisition unit is used to acquire the first end face image of the optical fiber bundle to be detected magnified by the lens group;

[0016] The image processing unit is used to execute the above method for detecting geometric parameters of the end face of an optical fiber bundle to generate the geometric parameters of the optical fiber bundle to be detected.

[0017] The present invention provides a method and device for detecting the geometric parameters of optical fiber bundle end faces. This method utilizes a conventional illumination source and obliquely projects light onto the cladding and coating surfaces, forming a peripheral aperture through diffuse reflection. This method enables geometric parameter detection of optical fibers with coatings and claddings. Furthermore, the method optimizes the light source brightness adjustment method, the oblique angle adjustment method, and the specific convolution parameters in the image edge extraction algorithm. This method not only adapts to optical fiber bundles of varying lengths and transmittances, but also improves detection efficiency and accuracy.

[0018] In order to make the above-mentioned objects, features and advantages of the invention more obvious and easy to understand, preferred embodiments of the present invention are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 1 is a flow chart of the method for detecting geometric parameters of an optical fiber bundle end face provided in Example 1;

[0021] Figure 2a-2d Schematic diagram of the convolution kernel in the geometric parameter detection method provided in Example 2;

[0022] Figure 3 3 is a schematic structural diagram of a device for detecting geometric parameters of an optical fiber bundle end face provided in Example 3;

[0023] Figure 4 4 is a schematic structural diagram of an image processing unit in the device for detecting geometric parameters of an optical fiber bundle end face provided in Example 4;

[0024] Figure 5 It is a schematic structural diagram of the geometric parameter detection device for the end face of an optical fiber bundle provided in Example 5. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] It should be noted that, unless there is a conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of the present invention. In addition, although the functional modules are divided in the device schematics and the logical order is shown in the flow charts, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flow charts. Furthermore, the terms "first," "second," "third," etc. used in the present invention do not limit the data or execution order, but only distinguish between identical or similar items with substantially the same functions and effects.

[0027] Figure 1 FIG. 1 is a flow chart of a method for detecting geometric parameters of an optical fiber bundle end face provided in Example 1. Figure 1 As shown, the following steps are included:

[0028] Step 1: Adjust the illumination angle and current illumination of the light source and obtain a first end face image of the optical fiber bundle to be inspected. The light emitted by the light source is obliquely incident on the optical fiber bundle to be inspected at a preset angle and optimal illumination.

[0029] In a specific embodiment, the illumination light source can be a parallel surface light source, such as an LED light source. The optical fiber bundle to be detected is a polished optical fiber bundle, the center of which is an imaging area with mirror reflection, while the outer cladding and coating layers are diffuse reflection.

[0030] The illumination source is adjusted to the optimal illumination and preset angle. The light emitted by the illumination source is then directed obliquely into the optical fiber bundle to be inspected, diffusely reflected by the cladding and coating layers of the optical fiber bundle, and then enters the lens assembly. A first end-face image of the optical fiber bundle to be inspected is then captured. The pixel values in the central imaging area of this first end-face image are low, while the pixel values in the peripheral cladding and coating regions are high, presenting two distinct annular regions. This can be used to extract the cladding and coating images of the optical fiber bundle to be inspected, thereby obtaining the corresponding geometric parameters, including cladding diameter, coating diameter, cladding out-of-roundness, imaging area / cladding concentricity, and imaging area / coating concentricity.

[0031] Then, step 2 is performed to preprocess the first end-face image to generate a second end-face image. This preprocessing includes smoothing, grayscale processing, and / or sharpening. Specifically, mathematical functions can be used to transform the grayscale values of the original image to enhance image contrast; Gaussian smoothing, average smoothing, and other methods can be used to reduce image noise and detail, making the image appear smoother and more uniform; and first-order differential operators can be used to sharpen the image to enhance image edges, thereby facilitating subsequent image processing steps. The specific processing steps are described in the prior art and will not be repeated here.

[0032] Then, proceed to step 3 to extract a gradient map from the preprocessed second end-face image. The gradient map highlights areas of the image with rapid grayscale changes, which typically correspond to fiber end-face edges, such as the core-cladding boundary. It also enhances local image features, making edges clearer. Therefore, by extracting the gradient map, these edges can be more accurately located, resulting in more precise geometric parameter measurements.

[0033] In a preferred embodiment, when performing a convolution operation on the pre-processed image, different convolution kernels are used for pixels at different pixel positions, thereby highlighting the local features of the image. Specifically, the following steps are included:

[0034] Calculate the position offset parameter a of each pixel point (i, j) in the second end surface image using the following formula:

[0035] Where i and j represent the horizontal and vertical coordinates of the pixel respectively, and W and H represent the width and height of the second end surface image respectively;

[0036] Query the preset mapping table and obtain the corresponding convolution kernel according to the range of the position offset parameter a. or When , the convolution kernel is:

[0037] [[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1]], such as Figure 2a As shown;

[0038] when When , the convolution kernel is:

[0039] [[0,1,1,1,1,1,1],[-1,0,1,1,1,1,1],[-1,-1,0,1,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,-1,0,1,1],[-1,-1,-1,-1,-1,0,1,1],[-1,-1,-1,-1,-1,0,1],[-1,-1,-1,-1,-1,0]], such as Figure 2b As shown;

[0040] when When , the convolution kernel is:

[0041] [[-1,-1,-1,-1,-1,-1,-1],[-1,-1,-1,-1,-1,-1,-1,-1],[-1,-1,-1,-1,-1,-1,-1,-1],[0,0,0,0,0,0,0],[1,1,1,1,1,1,1,1],[1,1,1,1,1,1,1,1]], e.g. Figure 2c As shown;

[0042] when When , the convolution kernel is:

[0043] [[1,1,1,1,1,1,0],[1,1,1,1,1,0,-1],[1,1,1,1,0,-1,-1],[1,1,1,0,-1,-1,-1],[1,1,0,-1,-1,-1,-1],[1,0,-1,-1,-1,-1,-1],[0,-1,-1,-1,-1,-1,-1]], such as Figure 2d shown.

[0044] Then, step 4 is performed to extract edges from the gradient image, and a preset ellipse fitting method and a preset circle fitting method are used to perform ellipse fitting and circle fitting on the extracted edge image, respectively, to obtain ellipse parameters and circle parameters corresponding to the fitted image. Specifically, the circle parameters include the center coordinates and diameter of the fitted circles corresponding to the outer edges of the imaging area, the outer edges of the cladding, and the outer edges of the coating layer, respectively; and the ellipse parameters include the major axis and minor axis of the fitted ellipse corresponding to the outer edges of the imaging area, the outer edges of the cladding, and the outer edges of the coating layer, respectively.

[0045] Exemplarily, the Canny edge detection method may be used to perform edge detection on the gradient image to extract the edge image of the coating layer and the edge image of the cladding layer. The specific method is described in the prior art and will not be repeated here.

[0046] Exemplarily, the preset ellipse fitting method and the preset circle fitting method can adopt the Hough method, the least squares method, etc., and fit by selecting qualified boundary points of the ellipse fitting or the circle fitting. Specifically, the Hough transform is applied on the above-mentioned edge map to detect ellipses, and the detection result will obtain three concentric ellipses, and the major axis and minor axis values of these ellipses are extracted respectively. Then, the Hough transform is continued to be applied on the above-mentioned edge map to detect circles, and the detection result will obtain three circles. The center positions of the three circles from the inside to the outside are respectively recorded as C1, C2, and C3, and the diameters are respectively recorded as D1, D2, and D3. The innermost circle 1 is the imaging circle, and the outer circles 2 and 3 are the outer circles of the cladding and the outer circles of the coating, that is, the area between circle 1 and circle 2 is the cladding, and the area between circle 2 and circle 3 is the coating.

[0047] Finally, step 5 is executed to calculate the geometric parameters of the optical fiber bundle to be detected based on the ellipse parameters and the circular parameters. For example, in a specific embodiment, the out-of-roundness of the imaging area is calculated as:

[0048]

[0049] Where A1 is the major axis of the innermost ellipse (i.e., the ellipse corresponding to the imaging area), and B1 is the minor axis of the innermost ellipse. In other embodiments, corresponding formulas can also be used to calculate the cladding layer non-circularity, coating layer non-circularity, etc., by simply replacing A1 and B1 with the major axis and minor axis of the cladding layer ellipse and coating layer ellipse, respectively. This is not further described here.

[0050] The concentricity of the coating layer and the imaging area is calculated as: the Euclidean distance between C1 and C3.

[0051] The concentricity of the cladding and the imaging area is calculated as: the Euclidean distance between C1 and C2.

[0052] The above embodiment provides a method for detecting the geometric parameters of the end face of an optical fiber bundle, which uses a common illumination light source and obliquely illuminates the surface of the cladding and coating layer, and forms a peripheral aperture through diffuse reflection, thereby enabling geometric parameter detection of optical fibers with coating layers and cladding layers.

[0053] In a preferred embodiment, the method further includes a light source adjustment step, i.e., a step of adjusting the light source to an optimal illumination, specifically:

[0054] S101, configuring a plurality of illumination levels with successively increasing illumination for the light source, and setting the initial illumination of the light source to an intermediate level;

[0055] S102, collecting a first end face image of the optical fiber bundle to be inspected, and calculating the actual imaging brightness corresponding to the current illumination level based on the first end face image;

[0056] S103, determine whether the actual imaging brightness is within the preset brightness range. If so, the current illumination is the optimal illumination. If the actual imaging brightness is higher than the preset brightness range, adjust the current illumination of the light source to the previous illumination level. If the actual imaging brightness is lower than the preset brightness range, adjust the current illumination of the light source to the next illumination level, and repeat S102-103 until the actual brightness is within the preset brightness range.

[0057] Exemplarily, the actual imaging brightness is one or more of the following: the sum of pixel values at all pixel positions in the first end-face image, the average pixel value at all pixel positions, the sum of pixel values at a target pixel position, and the average pixel value at a target pixel position. Furthermore, the preset brightness range is [0.8*T, 0.95*T], where T is the maximum brightness value of the image acquisition unit that generates the first end-face image.

[0058] In another preferred embodiment, the geometric parameter detection method further includes a light source angle adjustment step, specifically:

[0059] Obtaining geometric parameter values and / or fitting parameter values of the end face of the optical fiber bundle under optimal illumination;

[0060] Determine whether the geometric parameter value and / or the fitting parameter value meet the corresponding preset conditions; if so, keep the current oblique angle of the light source unchanged; if not, adjust the current oblique angle of the light source according to the determination result, and repeat steps 1 to 5;

[0061] The fitting parameter value includes the number of fitting points corresponding to the outer edge of the cladding and / or the outer edge of the coating layer when performing ellipse fitting or circle fitting using a preset ellipse fitting method or a preset circle fitting method.

[0062] Exemplarily, in another preferred embodiment of the geometric parameter inspection method, the light source angle adjustment step further includes:

[0063] Obtaining the transmittance of the optical fiber bundle to be tested, and establishing the preset condition according to the transmittance;

[0064] The preset condition includes at least one of the following conditions:

[0065] The number of fitting points at the outer edge of the cladding or coating is greater than the preset threshold;

[0066] The out-of-roundness of the imaging area, the out-of-roundness of the cladding layer or the out-of-roundness of the coating layer is within a first preset range;

[0067] The imaging area / cladding concentricity or the imaging area / coating layer concentricity is in a second preset range.

[0068] Specifically, these fitting points for fitting circles or fitting ellipses need to be distributed in various areas of the cladding or coating layer, and the number of fitting points that meet the conditions (clear imaging) in each area must meet a preset threshold.

[0069] In a preferred embodiment, when adjusting the light source to the optimal illumination and performing ellipse / circle fitting, the center point of the second end face image can be used as the center and the image can be divided into multiple regions of equal area at equal angles, such as fan-shaped regions, rectangular regions, etc. The number of fitting points in each region is calculated, and it is determined whether the number of fitting points in each region is greater than a preset threshold. Exemplarily, a fitting point distribution curve can be established based on the number of fitting points in each region, and the fitting point distribution curve can be compared with a preset standard curve. Based on the comparison results, target regions with an excessive and / or insufficient number of fitting points and the degree of deviation can be determined. A mapping relationship table established based on historical data can then be queried to obtain the target adjustment angle, and the current oblique angle of the light source can be adjusted.

[0070] In other embodiments, the need to adjust the oblique angle of the light source can also be determined based on the geometric parameter values of the fiber bundle end face detected under optimal illumination, such as the imaging area non-circularity, cladding non-circularity, or coating non-circularity, as well as the imaging area / cladding concentricity or imaging area / coating concentricity. For example, the value ranges of the various geometric parameters corresponding to the transmittance of different fiber lengths under optimal illumination can be pre-set. If the detected geometric parameter values exceed the pre-set ranges, it indicates that the detection results may be inaccurate, and the current oblique angle of the light source can be adjusted based on the degree of deviation.

[0071] The above preferred embodiment optimizes the light source brightness adjustment method, the oblique angle adjustment method, and the specific convolution parameters in the image edge extraction algorithm, etc., which can not only adapt to optical fiber bundles of different lengths and different transmittances, but also improve detection efficiency and accuracy.

[0072] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean 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.

[0073] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the above-mentioned method for detecting geometric parameters of an end face of an optical fiber bundle is implemented.

[0074] Figure 3 Schematic diagram of the structure of the optical fiber bundle end face geometric parameter detection device provided in Example 3, as shown in FIG. Figure 3 As shown, the apparatus comprises a light source 2, a lens assembly 7, an image acquisition unit 5, an image processing unit 4, and a clamping assembly for clamping a fiber bundle 15 to be detected. The clamping assembly comprises a proximal clamping device 8 for clamping one end of the fiber bundle to be detected near the lens assembly 7, and a distal clamping device 12 for clamping the other end. The light source 2 is disposed obliquely above the fiber bundle to be detected 15. Light emitted by the light source 2 is obliquely incident on the fiber bundle to be detected 15 at a preset angle, and enters the lens assembly 7 after diffuse reflection from the cladding and coating of the fiber bundle to be detected 15.

[0075] Exemplarily, the lens assembly 7 can be a collection of two or more lenses, which focus the light from the light source onto the image acquisition unit 5. The image acquisition unit 5 is a photoelectric conversion module, used to capture the first end-face image of the optical fiber bundle 15 to be inspected, magnified by the lens assembly 7. In specific scenarios, a CCD camera, CMOS camera, etc. can be used. The upper limit of brightness varies depending on the specific structure and can be denoted as T. The image acquisition unit 5 then transmits the first end-face image to the image processing unit 4, which executes the optical fiber bundle end-face geometric parameter detection method described in the above embodiment to generate the geometric parameters of the optical fiber bundle 15 to be inspected.

[0076] Figure 4 FIG. 4 is a schematic diagram of the structure of the image processing unit 4 in one embodiment. Figure 4 Shown, including:

[0077] The adjustment unit 100 is used to adjust the illumination angle and current illumination of the light source and obtain a first end face image of the optical fiber bundle to be inspected, wherein the light emitted by the light source is obliquely incident on the optical fiber bundle to be inspected at a preset angle and optimal illumination;

[0078] A pre-processing unit 200 is configured to pre-process the first end-face image to generate a second end-face image;

[0079] a gradient map generating unit 300 for performing convolution operations on pixels at different pixel positions in the second end-face image using different convolution kernels, and taking the absolute value of the convolution results pixel by pixel to generate a gradient map of the second end-face image;

[0080] A fitting unit 400 is configured to extract edges from the gradient image and perform ellipse fitting and circle fitting on the extracted edge image using a preset ellipse fitting method and a preset circle fitting method, respectively, to obtain ellipse parameters and circle parameters corresponding to the fitted image;

[0081] The calculation unit 500 is configured to calculate the geometric parameters of the optical fiber bundle to be tested according to the ellipse parameters and the circle parameters.

[0082] The geometric parameter detection device in the above embodiment uses a conventional illumination source and projects it obliquely onto the cladding and coating surfaces, creating a peripheral aperture through diffuse reflection. This allows for geometric parameter detection of optical fibers with both coatings and claddings. Simultaneously, optimizations have been made to the light source brightness adjustment method, the oblique illumination angle adjustment method, and the specific convolution parameters in the image edge extraction algorithm. This not only adapts to fiber bundles of varying lengths and transmittances, but also improves detection efficiency and accuracy.

[0083] In a preferred embodiment, the adjustment unit 100 includes a brightness adjustment unit, which is used to configure a plurality of illumination levels with successively increasing illumination for the light source, and set the initial illumination of the light source to an intermediate level; and is used to collect a first end face image of the optical fiber bundle to be detected, and calculate the actual imaging brightness corresponding to the current illumination level based on the first end face image; and is used to determine whether the actual imaging brightness is in a preset brightness range, and if so, the current illumination is the optimal illumination; if the actual imaging brightness is higher than the preset brightness range, the current illumination of the light source is lowered to the previous illumination level; if the actual imaging brightness is lower than the preset brightness range, the current illumination of the light source is raised to the next illumination level until the actual brightness is in the preset brightness range.

[0084] In a preferred embodiment, the adjustment unit 100 includes an angle adjustment unit, which is used to obtain the geometric parameter value and / or fitting parameter value of the end face of the optical fiber bundle, and determine whether the geometric parameter value and / or the fitting parameter value meet the corresponding preset conditions. If so, the current oblique angle of the light source is kept unchanged; if not, the current oblique angle of the light source is adjusted according to the judgment result; the fitting parameter value includes the number of fitting points corresponding to the outer edge of the cladding and / or the outer edge of the coating layer when a preset ellipse fitting method or a preset circular fitting method is used for ellipse fitting or circular fitting.

[0085] In a preferred embodiment, the angle adjustment unit is further configured to obtain the transmittance of the optical fiber bundle to be detected, and establish the preset condition according to the transmittance.

[0086] It should be noted that the above explanation of the embodiment of the method for detecting geometric parameters of an optical fiber bundle end face is also applicable to the apparatus for detecting geometric parameters of an optical fiber bundle end face in the above embodiment, and will not be repeated here.

[0087] like Figure 3 As shown, in a preferred embodiment, the geometric parameter detection device also includes a moving controller connected to the proximal clamping device in the clamping assembly, and the moving controller is used to move the proximal clamping device axially to make the end face of the optical fiber bundle to be detected approach or move away from the lens group to obtain the clearest end face image of the optical fiber bundle.

[0088] like Figure 3 As shown, in a preferred embodiment, the geometric parameter detection device also includes a display device 13 and a storage medium 14 connected to the image processing unit, the display device 13 is used to display the end face image of the optical fiber bundle and the corresponding detection results, and the storage medium 14 is used to store the end face image and the detection results.

[0089] An embodiment of the present invention further provides a device for detecting geometric parameters of an optical fiber bundle end face, comprising a computer-readable storage medium and a processor. When the processor executes a computer program on the computer-readable storage medium, the processor implements the steps of the above-mentioned method for detecting geometric parameters of an optical fiber bundle end face.

[0090] Figure 5 Schematic diagram of the structure of the optical fiber bundle end face geometric parameter detection device provided in Example 5 of the present invention, as shown in FIG. Figure 5 As shown, the optical fiber bundle end face geometric parameter detection device 8 of this embodiment includes: a processor 80, a readable storage medium 81, and a computer program 82 stored in the readable storage medium 81 and executable on the processor 80. When the processor 80 executes the computer program 82, the steps in the above-mentioned various method embodiments are implemented, such as Figure 1 Alternatively, when the processor 80 executes the computer program 82, the functions of the modules in the above-mentioned device embodiments are realized, for example Figure 4 Functionality of the modules shown.

[0091] Exemplarily, the computer program 82 may be divided into one or more modules, which are stored in the readable storage medium 81 and executed by the processor 80 to implement the present invention. The one or more modules may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 82 in the optical fiber bundle end face geometric parameter detection device 8.

[0092] The optical fiber bundle end face geometric parameter detection device 8 may include, but is not limited to, a processor 80 and a readable storage medium 81. Those skilled in the art will understand that Figure 5 It is only an example of the geometric parameter detection device 8 for the end face of an optical fiber bundle and does not constitute a limitation of the geometric parameter detection device 8 for the end face of an optical fiber bundle. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the geometric parameter detection device for the end face of an optical fiber bundle may also include a power management module, an operation processing module, input and output devices, network access equipment, a bus, etc.

[0093] The processor 80 may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0094] The readable storage medium 81 can be an internal storage unit of the optical fiber bundle end face geometric parameter detection device 8, such as a hard disk or memory of the optical fiber bundle end face geometric parameter detection device 8. The readable storage medium 81 can also be an external storage device of the optical fiber bundle end face geometric parameter detection device 8, such as a plug-in hard disk, a smart memory card (SmartMediaCard, SMC), a secure digital (SecureDigital, SD) card, a flash card (FlashCard), etc. equipped on the optical fiber bundle end face geometric parameter detection device 8. Furthermore, the readable storage medium 81 can also include both an internal storage unit and an external storage device of the optical fiber bundle end face geometric parameter detection device 8. The readable storage medium 81 is used to store the computer program and other programs and data required by the optical fiber bundle end face geometric parameter detection device. The readable storage medium 81 can also be used to temporarily store data that has been output or is to be output.

[0095] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by 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 embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. 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. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0096] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0097] Those skilled in the art will appreciate that the units and method 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. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0098] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0099] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0100] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0101] The present invention is not limited to what is described in the specification and embodiments, and additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described herein without departing from the spirit and scope of the general concept defined by the claims and their equivalents.

Claims

1. A method for detecting geometric parameters of an optical fiber bundle end face, characterized in that: The following steps are involved: Step 1: Adjust the illumination angle and current illumination of the light source and obtain a first end face image of the optical fiber bundle to be inspected, wherein the light emitted by the light source is obliquely incident on the optical fiber bundle to be inspected at a preset angle and optimal illumination; Step 2: preprocessing the first end face image to generate a second end face image; Step 3: performing convolution operations on pixels at different pixel positions in the second end face image using different convolution kernels, and taking the absolute value of the convolution results pixel by pixel to generate a gradient map of the second end face image; Step 4, performing edge extraction on the gradient image, and performing ellipse fitting and circle fitting on the extracted edge image using a preset ellipse fitting method and a preset circle fitting method, respectively, to obtain ellipse parameters and circle parameters corresponding to the fitted image; Step 5: Calculate the geometric parameters of the optical fiber bundle to be tested based on the ellipse parameters and the circle parameters.

2. The method for detecting geometric parameters of an optical fiber bundle end face according to claim 1, wherein: The convolution operation is performed on the pixels at different pixel positions in the second end face image using different convolution kernels, specifically: Calculate the position offset parameter a of each pixel point (i, j) in the second end surface image using the following formula: Where i and j represent the horizontal and vertical coordinates of the pixel respectively, and W and H represent the width and height of the second end surface image respectively; The preset mapping table is queried, and the corresponding convolution kernel is obtained according to the range of the position offset parameter a.

3. The method for detecting geometric parameters of an optical fiber bundle end face according to claim 2, wherein: when or When , the convolution kernel is: [[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,0,1,1,1]]； when When , the convolution kernel is: [[0,1,1,1,1,1,1],[-1,0,1,1,1,1,1],[-1,-1,0,1,1,1,1],[-1,-1,-1,0,1,1,1],[-1,-1,-1,-1,0,1,1],[-1,-1,-1,-1,-1,0,1],[-1,-1,-1,-1,-1,-1,0]]； when When , the convolution kernel is: [[-1,-1,-1,-1,-1,-1,-1],[-1,-1,-1,-1,-1,-1,-1],[-1,-1,-1,-1,-1,-1,-1],[0,0,0,0,0,0,0],[1,1,1,1,1,1,1],[1,1,1,1,1,1,1],[1,1,1,1,1,1,1]]； when When , the convolution kernel is: [[1,1,1,1,1,1,0],[1,1,1,1,1,0,-1],[1,1,1,1,0,-1,-1],[1,1,1,0,-1,-1,-1],[1,1,0,-1,-1,-1,-1],[1,0,-1,-1,-1,-1,-1],[0,-1,-1,-1,-1,-1,-1]]。 4. The method for detecting geometric parameters of an optical fiber bundle end face according to any one of claims 1 to 3, characterized in that: The circular parameters include the center coordinates and diameters of the fitting circles corresponding to the outer edge of the imaging area, the outer edge of the cladding layer, and the outer edge of the coating layer respectively; The ellipse parameters include the major axis and minor axis of the fitting ellipse corresponding to the outer edge of the imaging area, the outer edge of the cladding layer and the outer edge of the coating layer respectively; The geometric parameters include at least one of imaging area non-circularity, cladding non-circularity, coating non-circularity, imaging area / cladding concentricity, and imaging area / coating concentricity.

5. The method for detecting geometric parameters of an optical fiber bundle end face according to claim 4, characterized in that: Adjust the light source to the optimal illumination level, specifically: S101, configuring a plurality of illumination levels with successively increasing illumination for the light source, and setting the initial illumination of the light source to an intermediate level; S102, collecting a first end face image of the optical fiber bundle to be inspected, and calculating the actual imaging brightness corresponding to the current illumination level based on the first end face image; S103, determine whether the actual imaging brightness is within the preset brightness range. If so, the current illumination is the optimal illumination. If the actual imaging brightness is higher than the preset brightness range, adjust the current illumination of the light source to the previous illumination level. If the actual imaging brightness is lower than the preset brightness range, adjust the current illumination of the light source to the next illumination level, and repeat S102-103 until the actual brightness is within the preset brightness range.

6. The method for detecting geometric parameters of an optical fiber bundle end face according to claim 5, wherein: The actual imaging brightness is one or more of the sum of the pixel values of all pixel positions in the first end face image, the pixel average of all pixel positions, the sum of the pixel values of the target pixel position, and the pixel average of the target pixel position; the preset brightness range is [0.8*T, 0.95*T], where T is the maximum brightness value of the image acquisition unit that generates the first end face image.

7. The method for detecting geometric parameters of an optical fiber bundle end face according to claim 4, wherein: It also includes the steps of adjusting the light source angle, specifically: Obtaining geometric parameter values and / or fitting parameter values of the end face of the optical fiber bundle; Determine whether the geometric parameter value and / or the fitting parameter value meet the corresponding preset conditions; if so, keep the current oblique angle of the light source unchanged; if not, adjust the current oblique angle of the light source according to the determination result, and repeat steps 1 to 5; The fitting parameter value includes the number of fitting points corresponding to the outer edge of the cladding and / or the outer edge of the coating layer when performing ellipse fitting or circle fitting using a preset ellipse fitting method or a preset circle fitting method.

8. The method for detecting geometric parameters of an optical fiber bundle end face according to claim 7, wherein: The light source angle adjustment step further includes: Obtaining the transmittance of the optical fiber bundle to be tested, and establishing the preset condition according to the transmittance; The preset condition includes at least one of the following conditions: The number of fitting points at the outer edge of the cladding or coating is greater than the preset threshold; The out-of-roundness of the imaging area, the out-of-roundness of the cladding layer or the out-of-roundness of the coating layer is within a first preset range; The imaging area / cladding concentricity or the imaging area / coating layer concentricity is in a second preset range.

9. A device for detecting geometric parameters of an optical fiber bundle end face, characterized in that: It includes a light source, a lens group, an image acquisition unit, an image processing unit, and a clamping component for clamping the optical fiber bundle to be detected. The light source is obliquely arranged above the optical fiber bundle to be detected, and the light emitted by the light source is obliquely incident on the optical fiber bundle to be detected at a preset angle, and enters the lens group after diffuse reflection by the cladding and coating layer of the optical fiber bundle to be detected; The image acquisition unit is used to acquire the first end face image of the optical fiber bundle to be detected magnified by the lens group; The image processing unit is used to execute the method for detecting the geometric parameters of the end face of an optical fiber bundle according to any one of claims 1 to 8 to generate the geometric parameters of the optical fiber bundle to be detected.

10. The device for detecting geometric parameters of an optical fiber bundle end face according to claim 9, characterized in that: It also includes a movement controller connected to the proximal clamping device in the clamping assembly, and the movement controller is used to move the proximal clamping device along the axial direction to make the end face of the optical fiber bundle to be detected approach or move away from the lens group.

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