Optical fiber end face cutting angle detection method, device and system

Abstract

The application discloses a kind of optical fiber end face cutting angle detection methods, comprising: obtaining the detection image of one side of optical fiber end face;According to the detection image, the edge data of the optical fiber is extracted;According to the edge data, the first inclination of the two parallel edges of the optical fiber relative to the reference plane is calculated;The optical fiber end face is fitted as target straight line, and the second inclination of the target straight line relative to the reference plane is calculated;According to the first inclination and the second inclination, the cutting angle of the optical fiber end face relative to the parallel edge is calculated.It can improve the precision of optical fiber end face cutting angle detection, to improve the coupling efficiency and success rate of optical fiber.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of optical fiber product detection, and particularly relates to an optical fiber end face cutting angle detection method. BACKGROUND

[0002] Optical fiber coupling is an important link of optical fiber performance detection, and optical fiber cutting is an essential step before optical fiber coupling. Currently, a commonly used optical fiber cutting tool is a handheld cutting knife. Using such a cutting tool, the angle of the optical fiber cutting surface cannot be accurately controlled, and the angle of the optical fiber cutting surface affects the coupling efficiency and success rate of the optical fiber. Therefore, in order to avoid rework caused by coupling failure on an optical fiber automatic test system, an optical fiber cutting surface angle detection process needs to be added before optical fiber coupling. However, the current processing method of the optical fiber detection image still cannot calculate the accurate cutting surface angle, and therefore how to improve the accuracy of the optical fiber end face cutting angle detection is a problem to be solved at present. SUMMARY

[0003] In view of the above defects or improvement needs of the prior art, the present application provides an optical fiber end face cutting angle detection method, which can improve the accuracy of the optical fiber end face cutting angle detection, and improve the coupling efficiency and success rate of the optical fiber.

[0004] In one aspect, the present application provides an optical fiber end face cutting angle detection method, comprising: acquiring a detection image of one side of an optical fiber end face; extracting edge data of the optical fiber according to the detection image; calculating a first inclination angle of two parallel edges of the optical fiber relative to a reference plane according to the edge data; fitting the optical fiber end face as a target straight line, and calculating a second inclination angle of the target straight line relative to the reference plane; and calculating a cutting angle of the optical fiber end face relative to the parallel edges according to the first inclination angle and the second inclination angle.

[0005] In one embodiment of the present application, the extraction of the edge data of the optical fiber according to the detection image comprises: adjusting the brightness and contrast of the detection image; filtering and denoising the two parallel edges of the optical fiber, and thresholding the detection image to obtain the edge data of the optical fiber.

[0006] In one embodiment of the present application, the calculation of the first inclination angle of the two parallel edges of the optical fiber relative to the reference plane according to the edge data comprises: selecting a fixed size rectangle covering the optical fiber end face in the detection image; performing image cutting through ROI processing to obtain a rectangular image, and calculating the first inclination angle according to a third inclination angle between the rectangular image and the reference plane.

[0007] In one embodiment of the present application, after the rectangular image is obtained, the method further comprises: performing morphological processing on the rectangular image, the morphological processing comprising: first performing dilation processing, and then performing erosion processing.

[0008] In one embodiment of the present application, the fitting the fiber end face to a target straight line comprises: selecting a plurality of specified points on the fiber end face in the detection image, and representing each specified point in polar coordinates; representing all straight lines passing through each specified point in the polar coordinates to obtain a corresponding sinusoidal curve; selecting a target intersection point at which the number of sinusoidal curves exceeds a preset threshold, and taking the straight line corresponding to the target intersection point as a target straight line.

[0009] In one embodiment of the present application, the obtaining the detection image of one side of the fiber end face comprises: rotating the fiber around its own axis, and obtaining a plurality of detection images of different angles of one side of the fiber end face during the rotation.

[0010] In one embodiment of the present application, after the cutting angle of the fiber end face relative to the parallel edges is calculated, the method further comprises: selecting a maximum cutting angle from the cutting angles corresponding to each detection image; and judging whether the fiber end face is qualified according to the maximum cutting angle.

[0011] In another aspect, an embodiment of the present application provides a fiber end face cutting angle detection device, comprising: a detection image obtaining module configured to obtain a detection image of one side of a fiber end face; an edge data extracting module configured to extract edge data of the fiber according to the detection image; an inclination angle calculating module configured to calculate a first inclination angle of two parallel edges of the fiber relative to a reference plane according to the edge data; a straight line fitting module configured to fit the fiber end face to a target straight line, and calculate a second inclination angle of the target straight line relative to the reference plane; and a cutting angle calculating module configured to calculate a cutting angle of the fiber end face relative to the parallel edges according to the first inclination angle and the second inclination angle.

[0012] In yet another aspect, an embodiment of the present application provides a fiber end face cutting angle detection system, comprising: a memory and one or more processors connected to the memory, the memory storing a computer program, and the processor being configured to execute the computer program to implement the fiber end face cutting angle detection method according to any one of the above embodiments.

[0013] In still another aspect, an embodiment of the present application provides a computer readable storage medium, the computer readable storage medium storing computer executable instructions, the computer executable instructions being configured to execute the fiber end face cutting angle detection method according to any one of the above embodiments.

[0014] Compared with the prior art, the above scheme of the present application can have one or more of the following beneficial effects:

[0015] (1) By acquiring the detection image of the side of the fiber end face and extracting the fiber edge data, the included angle between the two parallel edges of the fiber and the reference plane is calculated, the fiber end face is fitted as a straight line and the included angle between the straight line and the reference plane is calculated, and the cutting angle of the fiber end face can be accurately and conveniently calculated through the relationship between the two included angles;

[0016] (2) When extracting the fiber edge data, a fixed size rectangular image covering a certain range of the fiber end face is selected for subsequent image analysis and processing, which can increase the efficiency of image analysis and processing, and after obtaining the minimum rectangular image, morphological processing is performed, first inflation and then corrosion, which can obtain complete and accurate image and avoid the problem of partial image loss;

[0017] (3) By selecting a plurality of specified points on the fiber end face and representing all straight lines passing through each specified point in polar coordinates, the corresponding sinusoidal curves are obtained, and the target intersection point whose number of sinusoidal curves intersecting at a point exceeds a predetermined threshold is selected, and the straight line corresponding to the target intersection point is selected as the target straight line, which can greatly improve the precision of the fiber end face cutting angle detection and improve the coupling efficiency and success rate of the fiber;

[0018] (4) The fiber is rotated around its own axis, a plurality of detection images of different angles of the side of the fiber end face are acquired during the rotation, and the corresponding end face cutting angles are calculated, and the maximum cutting angle is used as a standard to judge whether the fiber cutting is qualified, which can better ensure that the fiber cutting angle is within the qualified range and further improve the success rate of fiber coupling.

[0019] Other aspects of the application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the application. It should be understood, however, that the drawings and description thereto are not intended to limit the application to the subject application alone. Rather, it is to be understood that unless otherwise indicated, the examples set forth herein are not meant to be limiting as to a scope of the application. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A flowchart of the fiber end face cutting angle detection method provided for the embodiment of the present application is shown in the figure;

[0021] Figure 2 A fiber detection image schematic diagram provided for the embodiment of the present application is shown in the figure;

[0022] Figure 3 A schematic diagram of selecting a rectangular image provided for the embodiment of the present application is shown in the figure;

[0023] Figure 4A specific execution step schematic diagram of the optical fiber end face cutting angle detection method provided by the embodiment of the present application is shown in the figure.

[0024] Figure 5 A schematic diagram of fitting the optical fiber end face as a straight line is shown in the figure.

[0025] Figure 6 A schematic diagram of representing the sinusoidal curve corresponding to the specified point on the optical fiber end face in polar coordinates is shown in the figure.

[0026] Figure 7 A structure schematic diagram of the optical fiber end face cutting angle detection device provided by the embodiment of the present application is shown in the figure.

[0027] Figure 8 A structure schematic diagram of the optical fiber end face cutting angle detection system provided by the embodiment of the present application is shown in the figure.

[0028] Figure 9 A structure schematic diagram of the computer readable storage medium provided by the embodiment of the present application is shown in the figure.

[0029] Explanation of reference signs

[0030] S11-S15: Steps of the optical fiber end face cutting angle detection method.

[0031] 20: Optical fiber end face cutting angle detection device; 201: Detection image acquisition module; 202: Edge data extraction module; 203: Inclination angle calculation module; 204: Straight line fitting module; 205: Cutting angle calculation module.

[0032] 30: Optical fiber end face cutting angle detection system; 31: Processor; 32: Memory.

[0033] 40: Computer readable storage medium. DETAILED DESCRIPTION

[0034] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described below with reference to the accompanying drawings and in combination with the embodiments.

[0035] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments, and all should belong to the protection scope of the present application.

[0036] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," or "includes" and / or "including" when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0037] It is also to be understood that the division of embodiments in the present application is only for the convenience of description, and should not constitute a special limitation, and the features in various embodiments can be combined with each other without contradiction, and can be mutually quoted.

[0038] As shown in Figure 1 The first embodiment of the present application provides a method for detecting the cutting angle of the fiber end face, for example, including: step S1, obtaining a detection image of one side of the fiber end face; step S2, extracting edge data of the fiber according to the detection image; step S3, calculating a first inclination angle of two parallel edges of the fiber relative to a reference plane according to the edge data; step S4, fitting the fiber end face as a target straight line, and calculating a second inclination angle of the target straight line relative to the reference plane, and step S5, calculating the cutting angle of the fiber end face relative to the parallel edges according to the first inclination angle and the second inclination angle.

[0039] In step S1, the detection image is obtained by photographing one side of the fiber end face by a camera, and the detection image is obtained by a host computer. The host computer is, for example, a personal computer, a handheld device, a portable device, a tablet device, a multi-processor system, a microprocessor-based system, an editable consumer electronic device, a network PC, a small computer, a large computer, or a distributed computing environment including any of the above systems or devices, etc.

[0040] In step S2, the host computer extracts the edge data of the fiber according to the detection image. Specifically, as shown in Figure 2 The two parallel edges and the cutting end face of the fiber can be displayed in the image processing software of the host computer. After obtaining the detection image, image preprocessing is performed, for example, including: adjusting the brightness and contrast of the detection image, filtering and denoising the two parallel edges of the fiber, and thresholding the processed detection image, so as to obtain accurate fiber edge data, which is the image data of the fiber edge.

[0041] In step S3, the edge data of the optical fiber is detected, for example, based on the reference surface, and the image processing software can calculate the first inclination angle of the two parallel edges of the optical fiber relative to the reference surface according to the edge data. In addition, since the core layer of the optical fiber has high brightness and cannot be removed, after the edge data of the optical fiber is extracted, the core layer detection image of the optical fiber is filled, for example, by using an edge point arbitrary connection line, to obtain more accurate and complete edge data of the optical fiber.

[0042] Further, as shown in Figure 3 In the process of extracting the edge data of the optical fiber, a fixed size rectangle covering a certain range of the end surface of the optical fiber is selected as a minimum rectangular image, the minimum rectangular image is cut by the ROI (region of interest) processing mode, and the subsequent image analysis processing is performed on the minimum rectangular image. In this way, the efficiency of image analysis processing can be improved. The first inclination angle of the parallel edges of the optical fiber relative to the reference surface can be indirectly calculated through the third inclination angle between the minimum rectangular image and the reference surface. It should be noted that the size of the minimum rectangular image can be customized by the user, and it needs to consider the placement position offset of the optical fiber and the difference in the end surface cutting angle of different optical fibers, so as to ensure that the minimum rectangular image covers the cutting end surface of the optical fiber.

[0043] Further, as shown in Figure 4 After obtaining the minimum rectangular image, the minimum rectangular image is also subjected to morphological processing, for example, first subjected to inflation processing, and then subjected to erosion processing, to obtain a complete and accurate image, and to avoid the problem of image partial loss.

[0044] In step S4, the end surface part of the optical fiber in the detection image is fitted as a straight line, i.e. a target straight line, and the image detection software can calculate the second inclination angle of the target straight line relative to the reference surface according to the image data of the target straight line.

[0045] Specifically, the end surface of the optical fiber is fitted as a straight line by using the Hough Transform principle. Hough Transform is a feature extraction technique in image processing. The process obtains a set of lines that meet the specific shape as the Hough Transform result by calculating the local maximum value of the cumulative result in a parameter space. As shown in Figure 5 The straight line can be represented by rectangular coordinates or polar coordinates. When the straight line is represented by rectangular coordinates, the slope of the straight line perpendicular to the x-axis cannot be represented, so the polar coordinates are selected to represent the straight line. The expression of the straight line is, for example,

[0046]

[0047] After simplifying, we get: r = x cos θ + y sin θ; therefore, for any given point, all the straight lines passing through this given point can be defined as: r = x cos θ + y sin θ. This means that for any given point (x0, y0), each polar coordinate representation corresponds to a straight line passing through the given point (x0, y0).

[0048] If all the straight lines passing through a given point are drawn in the polar radius-polar angle plane, a sinusoidal curve will be obtained, as shown in Figure 6 For example, after performing the above operation on a plurality of given points on the fiber end face in the detection image, a plurality of sinusoidal curves are obtained. If two sinusoidal curves intersect in the plane, it means that the corresponding given points pass through the same straight line.

[0049] In this way, the target straight line can be detected by finding the number of curves intersecting at a point in the above plane. The more curves intersecting at a point means that the intersection point represents a straight line passing through more given points. For example, a predetermined number threshold can be set. When it is determined that the number of sinusoidal curves intersecting at the target point exceeds the number threshold, the straight line corresponding to the target point is selected as the target straight line.

[0050] In step S5, since the target straight line fitted according to the foregoing can be used to calculate the second inclination angle between the target straight line and the reference plane, the image processing software can accurately calculate the fiber end face cutting angle corresponding to the detection image according to the calculated second inclination angle and the first inclination angles between the two parallel edges of the fiber and the reference plane. In this way, compared with the prior art of directly determining the fiber end face cutting angle based on the obtained detection image, the accuracy of the fiber end face cutting angle detection can be greatly improved to improve the coupling efficiency and success rate of the fiber.

[0051] Further, the obtaining of the detection image on one side of the fiber end face specifically includes: rotating the fiber around its own axis, and obtaining a plurality of detection images of different angles on one side of the fiber end face during the rotation. In the subsequent image processing step, the corresponding end face cutting angle can be calculated for each detection image. In an embodiment, for example, the maximum cutting angle among the cutting angles corresponding to each detection image is selected, and the fiber cutting is judged to be qualified based on the maximum cutting angle. In this way, the fiber cutting angle can be better ensured to be within the qualified range, further improving the success rate of fiber coupling.

[0052] In summary, the first embodiment of the present application provides a fiber end face cutting angle detection method, which obtains a detection image on one side of the fiber end face and extracts fiber edge data to calculate the included angle between the two parallel edges of the fiber and the reference plane, fits the fiber end face as a straight line and calculates the included angle between the straight line and the reference plane, and accurately and conveniently calculates the fiber end face cutting angle through the relationship between the two included angles. When extracting the fiber edge data, a fixed size rectangular image covering a certain range of the fiber end face is selected for subsequent image analysis and processing, which can increase the efficiency of image analysis and processing. After obtaining the minimum rectangular image, morphological processing is performed, first inflation and then corrosion, which can obtain a complete and accurate image and avoid the problem of image partial loss. By selecting a plurality of specified points on the fiber end face and representing all straight lines passing through each specified point in polar coordinates to obtain the corresponding sinusoidal curves, selecting a target intersection point where the number of sinusoidal curves intersecting at the point exceeds a preset threshold, and taking the straight line corresponding to the target intersection point as the target straight line, the accuracy of fiber end face cutting angle detection can be greatly improved to improve the coupling efficiency and success rate of the fiber.

[0053] As shown in Figure 6 The second embodiment of the present application provides a fiber end face cutting angle detection device 20, for example, which includes a detection image acquisition module 201, an edge data extraction module 202, an inclination angle calculation module 203, a straight line fitting module 204, and a cutting angle calculation module 205.

[0054] The detection image acquisition module 201 is configured to acquire a detection image on one side of the fiber end face. The edge data extraction module 202 is configured to extract edge data of the fiber based on the detection image. The inclination angle calculation module 203 is configured to calculate a first inclination angle of the two parallel edges of the fiber relative to a reference plane based on the edge data. The straight line fitting module 204 is configured to fit the fiber end face as a target straight line and calculate a second inclination angle of the target straight line relative to the reference plane. The cutting angle calculation module 205 is configured to calculate a cutting angle of the fiber end face relative to the parallel edges based on the first inclination angle and the second inclination angle.

[0055] The optical fiber end face cutting angle detection method realized by the optical fiber end face cutting angle detection device 20 disclosed by the second embodiment of the present application is as described in the first embodiment, and thus will not be described in detail here. Alternatively, each module in the second embodiment and the other operations or functions described above are respectively used to implement the method described in the first embodiment, and the beneficial effects of the present embodiment are the same as those of the first embodiment. For brevity, they will not be described here.

[0056] As shown in Figure 8 The third embodiment of the present application proposes an optical fiber end face cutting angle detection system 30, for example, comprising a memory 32 and one or more processors 31 connected to the memory 32. The memory 32 stores a computer program, and the processor 31 is configured to execute the computer program to implement the optical fiber end face cutting angle detection method as described in the first embodiment. For brevity, the specific method will not be described here, and the beneficial effects of the optical fiber end face cutting angle detection system 30 provided by the present embodiment are the same as those of the optical fiber end face cutting angle detection method provided by the first embodiment.

[0057] As shown in Figure 5 The fourth embodiment of the present application proposes a computer readable storage medium 40, which is a non-volatile memory and stores computer readable instructions. When the computer readable instructions are executed by one or more processors, the one or more processors are caused to execute the optical fiber end face cutting angle detection method as described in the first embodiment. For brevity, the specific method will not be described here, and the beneficial effects of the computer readable storage medium 40 provided by the present embodiment are the same as those of the optical fiber end face cutting angle detection method provided by the first embodiment.

[0058] In addition, it can be understood that the above-mentioned embodiments are only exemplary descriptions of the present application, and the technical solutions of each embodiment can be arbitrarily combined and used without conflicting technical features, contradictory structures, or violating the purpose of the present application.

[0059] In the several embodiments of the present application, it should be understood that the disclosed system, device and / or method can be implemented in other ways. For example, the device embodiments described above are only schematic. The division of the units / modules is only a logical function division. There can be another division manner for actual implementation. For example, multiple units or modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or in other forms.

[0060] The units / modules described as separate components may or may not be physically separate, and the components shown as units / modules may or may not be physical units, i.e., may be located in one place or distributed on multiple network units. Part or all of the units / modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0061] In addition, the functional units / modules in each embodiment of the present application can be integrated in one processing unit / module, or each unit / module can exist physically, or two or more units / modules can be integrated in one unit / module. The integrated unit / module can be realized in the form of hardware or in the form of hardware plus software functional unit / module.

[0062] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present application.

Claims

1. A method for detecting the cutting angle of an optical fiber end face, characterized in that, include: Acquire a detection image from one side of the fiber end face; Extract the edge data of the optical fiber based on the detected image; Calculating the first tilt angle of the two parallel sides of the optical fiber relative to the reference plane based on the edge data includes: selecting a fixed-size rectangle covering the end face of the optical fiber in the detection image; performing image segmentation through ROI processing to obtain a rectangular image; and calculating the first tilt angle based on the third tilt angle between the rectangular image and the reference plane. The fiber end face is fitted to the target straight line, and the second tilt angle of the target straight line relative to the reference plane is calculated; The cutting angle of the fiber end face relative to the parallel side is calculated based on the first tilt angle and the second tilt angle; Wherein, fitting the fiber end face to the target straight line includes: Select several designated points on the end face of the optical fiber in the detection image, and represent each designated point in polar coordinates; All straight lines passing through each of the specified points are represented in the polar coordinates to obtain their respective corresponding sine curves; Select a target intersection point where the number of sine curves intersecting at a single point exceeds a preset threshold, and use the straight line corresponding to the target intersection point as the target straight line; The acquisition of the detection image on one side of the fiber end face includes: The optical fiber is rotated around its own axis, and several detection images at different angles are acquired on one side of the end face of the optical fiber during the rotation process. After calculating the cutting angle of the fiber end face relative to the parallel side, the method further includes: Select the maximum cutting angle from the cutting angles corresponding to each of the detected images; The fiber end face is judged to be qualified based on the maximum cutting angle.

2. The fiber optic end-face cutting angle detection method according to claim 1, characterized in that, The step of extracting the edge data of the optical fiber based on the detected image includes: Adjust the brightness and contrast of the detected image; The two parallel edges of the optical fiber are filtered and denoised, and the detected image is thresholded to obtain the edge data of the optical fiber.

3. The fiber optic end-face cutting angle detection method according to claim 1, characterized in that, After obtaining the rectangular image, the process also includes: The rectangular image is subjected to morphological processing, which includes: first dilation, then erosion.

4. A fiber optic end-face cutting angle detection device, characterized in that, The method for detecting the fiber end face cutting angle as described in any one of claims 1 to 3 includes: The detection image acquisition module is used to acquire the detection image of one side of the fiber end face; An edge data extraction module is used to extract edge data of the optical fiber based on the detected image. The tilt angle calculation module is used to calculate the first tilt angle of the two parallel sides of the optical fiber relative to the reference plane based on the edge data, including: selecting a fixed-size rectangle covering the end face of the optical fiber in the detection image; performing image segmentation through ROI processing to obtain a rectangular image; and calculating the first tilt angle based on the third tilt angle between the rectangular image and the reference plane. A straight line fitting module is used to fit the fiber end face into a target straight line and calculate the second tilt angle of the target straight line relative to the reference plane; The cutting angle calculation module is used to calculate the cutting angle of the fiber end face relative to the parallel side based on the first tilt angle and the second tilt angle. Wherein, fitting the fiber end face to the target straight line includes: Select several designated points on the end face of the optical fiber in the detection image, and represent each designated point in polar coordinates; All straight lines passing through each of the specified points are represented in the polar coordinates to obtain their respective corresponding sine curves; Select a target intersection point where the number of sine curves intersecting at a single point exceeds a preset threshold, and use the straight line corresponding to the target intersection point as the target straight line.

5. A fiber optic end-face cutting angle detection system, characterized in that, include: A memory and one or more processors connected to the memory, the memory storing a computer program, and the processors executing the computer program to implement the fiber optic end-face cutting angle detection method as described in any one of claims 1 to 3.

6. A computer-readable storage medium storing computer-executable instructions for performing the fiber optic end-face cutting angle detection method as described in any one of claims 1 to 3.

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