A method and system for focusing an optical fiber core

Abstract

The present invention discloses a focusing method for an optical fiber core, comprising: obtaining a first position core image of an optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision; calculating the core boundary pixel point statistics of the first position core image and the second position core image; comparing and analyzing the pixel point difference between the first boundary pixel point statistics of the first position core image and the second boundary pixel point statistics of the second position core image according to a focusing strategy, and analyzing the pixel point difference between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core; adjusting the preset step value according to the pixel point difference, obtaining the target step value with the minimum pixel point difference, as the optimal focusing position of the optical fiber core. The beneficial effect of the present invention is that it can realize the rapid and accurate finding of the optimal focusing position.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of optical fibers, and in particular to a method and system for focusing an optical fiber core. Background Art

[0002] As a carrier of information, optical fiber is an important part of the optical fiber communication system and is widely used in the fields of communication and sensing. Optical fiber itself is a good carrier of light, with the characteristics of fast transmission speed, low loss, and strong confidentiality. It is widely used in data transmission in the field of communication. At the same time, with the development of micro-nano processing technology, the precision of precision processing is getting higher and higher, and the demand for special processing of optical fiber is gradually increasing, and the application is becoming more extensive. There are different processing methods for different needs, which makes optical fiber processing particularly important.

[0003] However, the current processing methods all have certain problems, namely, the problem of focusing the position of the fiber core. Since the optical fiber has a multi-layer structure, from the outer coating layer, cladding to the core, the refractive index of each layer is different, and the optical fiber is a special circular waveguide, which will produce a self-focusing effect. Therefore, it is difficult to directly locate the center of the fiber core under a microscope. For the processing of the grating structure of the optical fiber core, the best processing position is the center of the optical fiber core. Therefore, before processing the optical fiber, it is very necessary to focus and position the optical fiber core. Summary of the invention

[0004] In view of this, an object of an embodiment of the present invention is to provide a method and system for focusing an optical fiber core, which can achieve rapid and accurate finding of the optimal focusing position.

[0005] To achieve the above object, an embodiment of the present invention provides a method for focusing an optical fiber core, comprising:

[0006] Acquire a first position core image of the optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision;

[0007] Calculating the core boundary pixel statistics of the first position core image and the second position core image;

[0008] Comparatively analyzing pixel point differences between first boundary pixel point statistics of the fiber core image at the first position and second boundary pixel point statistics of the fiber core image at the second position according to the focusing strategy, and analyzing pixel point differences between boundary pixel points of the optical fiber core and background pixel points of the optical fiber core;

[0009] The preset step value is adjusted according to the pixel point difference to obtain the target step value with the minimum pixel point difference as the optimal focusing position of the optical fiber core.

[0010] Furthermore, the method of acquiring a first position core image of the optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision includes:

[0011] Focusing an external light source onto the core of the optical fiber by a focusing device;

[0012] A first position core image of the optical fiber at an initial position and a second position core image of the optical fiber core at a preset step value are acquired based on machine vision.

[0013] Further, the calculating of the core boundary pixel statistics of the first position core image and the second position core image includes:

[0014] Performing denoising processing on the first position core image and the second position core image;

[0015] Grayscale the denoised first position fiber core image and the second position fiber core image to obtain a binary image;

[0016] The binary image is processed according to a dynamic threshold algorithm to obtain core boundary pixel statistics of the first position core image and the second position core image.

[0017] Furthermore, the grayscale processing of the denoised first position core image and the second position core image to obtain a binary image includes:

[0018] intercepting the ROI area of ​​the first position core image and the second position core image;

[0019] Grayscale boundary recognition is performed on the ROI region, and grayscale processing is performed on the ROI region to obtain a binary image of the optical fiber core boundary.

[0020] Further, the comparing and analyzing the difference between the first boundary pixel point statistics of the core image at the first position and the second boundary pixel point statistics of the core image at the second position according to the focusing strategy includes:

[0021] Obtaining a first pixel ratio of a core boundary of the optical fiber core in the first boundary pixel point statistics and a second pixel ratio of a core boundary of the optical fiber core in the second boundary pixel point statistics;

[0022] The adjustment direction of the preset step value is determined according to the difference between the first pixel proportion and the second pixel proportion.

[0023] Further, the analyzing the pixel point difference between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core includes:

[0024] Counting the proportion of the boundary highlight area of ​​the first boundary pixel point statistics of the core image at the first position to the second boundary pixel point statistics of the core image at the second position;

[0025] A focusing strategy is used to analyze a statistical graph of the proportion of the boundary highlight area to obtain the optimal focusing position of the optical fiber core.

[0026] Furthermore, the adopting of a focus strategy to analyze a statistical graph of the proportion of a boundary highlight area to obtain an optimal focus position of the optical fiber core includes:

[0027] If the proportion of the boundary highlight area corresponding to the core image at the first position is greater than the proportion of the boundary highlight area corresponding to the core image at the second position, it means that the position corresponding to the core image at the first position is the best focus position;

[0028] If the proportion of the boundary highlight area corresponding to the core image at the first position is smaller than the proportion of the boundary highlight area corresponding to the core image at the second position, it means that the position corresponding to the core image at the second position is the best focus position.

[0029] Furthermore, the method further comprises:

[0030] If the pixel difference is greater than the preset range, repeat the following steps:

[0031] Acquire a first position core image of the optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision;

[0032] Calculating the core boundary pixel statistics of the first position core image and the second position core image;

[0033] According to the focusing strategy, the pixel point differences between the first boundary pixel point statistics of the fiber core image at the first position and the second boundary pixel point statistics of the fiber core image at the second position are compared and analyzed, and the pixel point differences between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core are analyzed.

[0034] To achieve the above object, an embodiment of the present invention provides a focusing system for an optical fiber core, comprising:

[0035] A displacement platform, used for fixing an optical fiber fixture on which an optical fiber is placed and an amplifying element;

[0036] A light source, placed between the optical fiber fixture and the optical fiber, for providing background light for the optical fiber;

[0037] A depth camera, used to obtain the real-time position of the optical fiber and to image the optical fiber to obtain a depth image;

[0038] The amplifying element is placed between the displacement platform and the depth camera, and is used to amplify the optical fiber;

[0039] A control center is connected to the displacement platform and the depth camera, and is used to control the depth camera to shoot and control the displacement platform to move.

[0040] Furthermore, the amplifying element moves on the displacement platform.

[0041] An embodiment of the present invention provides a focusing method and system for an optical fiber core. By acquiring a first-position core image at an initial position and a second-position core image moved at a preset step value, and then calculating pixel point statistics at the core boundary, the difference is compared through the pixel point statistics data of the two images. At the same time, the grayscale value of the fiber core boundary and the background grayscale value difference are combined to determine the vertical movement direction of the optical fiber and the target step value, so as to quickly and accurately find the best focusing position. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flow chart of Embodiment 1 of the optical fiber core focusing method of the present invention.

[0043] Figure 2 Flow chart of step S100 in an embodiment of the present invention.

[0044] Figure 3 Flow chart of step S120 in an embodiment of the present invention.

[0045] Figure 4 Flow chart of step S122 in an embodiment of the present invention.

[0046] Figure 5 Flow chart of step S140 in an embodiment of the present invention.

[0047] Figure 6 FIG. 4 is a flowchart of another embodiment of step S140 in an embodiment of the present invention.

[0048] Figure 7 Flow chart of step S140B in an embodiment of the present invention.

[0049] Figure 8 It is a schematic diagram of Embodiment 2 of the optical fiber core focusing method of the present invention.

[0050] Fig. 9 This is the first analytical diagram of Embodiment 1 of the optical fiber core focusing method of the present invention.

[0051] Fig.10 This is the second analytical diagram of Embodiment 1 of the optical fiber core focusing method of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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.

[0053] Embodiment 1

[0054] like Figure 1 As shown, an embodiment of the present invention describes a method for focusing an optical fiber core, comprising:

[0055] Step S100: acquiring a first position core image of an optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision.

[0056] Specifically, the optical fiber core is placed on a displacement platform, which can be a three-dimensional adjustment platform. The optical fiber core is fixed by an optical fiber clamp, and the brightness of the background light source is adjusted. Machine vision, that is, by using an image acquisition device with depth information, to obtain the first position core image and the second position core image. Therefore, the first position core image and the second position core image respectively carry corresponding depth information: initial position, preset step value. By obtaining the top-down images of the optical fiber at different depths, the features of the boundary of the optical fiber core are obtained, and the obtained features are not limited to the line width of the boundary, the contrast value of the boundary, and the grayscale statistical value of the boundary.

[0057] For example, see Figure 2 , the step S100 further comprises:

[0058] Step S101, focusing an external light source onto the core of the optical fiber through a focusing device.

[0059] Specifically, a background light source is set for the optical fiber core, and the external light source is focused on the optical fiber core through a focusing device, which can be an objective lens, and adjusted so that the image acquisition device can capture a clear optical fiber core image. The image acquisition device can be a CCD optical switch.

[0060] Step S102, obtaining a first position core image of the optical fiber at an initial position and a second position core image of the optical fiber core at a preset step value based on machine vision.

[0061] Specifically, the preset step value is estimated in advance, and the image acquisition device is set on a three-dimensional adjustment platform. The distance between the image acquisition device and the optical fiber core is increased by adjusting the three-dimensional adjustment platform. When adjusted to the preset step value, the core image at the second position is acquired.

[0062] Step S120, calculating the statistics of the core boundary pixels of the first position core image and the second position core image.

[0063] Specifically, the boundary grayscale area between the first position core image and the second position core image is obtained, and the boundary grayscale area is grayscaled and binarized to obtain a core boundary binary image, and pixel counts are performed on the core boundary binary image to obtain a histogram of the core boundary pixel values.

[0064] For example, see Figure 3 , the step S120 further comprises:

[0065] Step S121, performing denoising processing on the first position core image and the second position core image.

[0066] Specifically, Gaussian filtering is performed on the acquired fiber core image at the first position and the fiber core image at the second position to eliminate the background noise of the images, so as to ensure the correctness of the statistical value and the statistical value of the core boundary pixel.

[0067] Step S122, grayscale processing is performed on the denoised first position core image and the second position core image to obtain a binary image.

[0068] Specifically, the denoised first position core image and the second position core image are grayed, and the ROI area is intercepted to obtain a boundary gray image. The boundary gray image is then binarized to obtain a binary image containing only two values, 0 or 1. ROI (region of interest) area. In machine vision and image processing, the area to be processed is outlined from the first position core image and the second position core image in the form of a box, circle, ellipse, irregular polygon, etc., which is called the region of interest, ROI. Various operators and functions are often used in machine vision software such as Halcon, OpenCV, and Matlab to obtain the region of interest ROI and perform the next step of image processing.

[0069] For example, see Figure 4 , the step S122 further comprises:

[0070] Step S122A, intercepting the ROI area of ​​the first position core image and the second position core image.

[0071] Specifically, the ROI region is the fiber core region, including the grayscale region of the fiber core boundary and the pipeline core boundary, which can be captured by OpenCV digital image processing. The full name of OpenCV is Open source Computer Vision Library. OpenCV is an open source function library for image processing, analysis, and machine vision. By performing feature recognition on the boundary region in the first position fiber core image and the second position fiber core image, the ROI region is captured.

[0072] Step S122B, performing grayscale boundary recognition on the ROI area, and grayscale processing on the ROI area to obtain a binary image of the optical fiber core boundary.

[0073] Specifically, Fig. 9 As shown in (a) and (b), there is a certain difference in the grayscale between the fiber core boundary and the background, and this difference has a continuous change trend at different focus depths. The grayscale boundary of the ROI area is identified and grayscale processed, the grayscale of the boundary of the ROI area is distinguished from the background, and then binarization is performed to obtain a binary image of the fiber core boundary.

[0074] Step S123, processing the binary image according to a dynamic threshold algorithm to obtain core boundary pixel statistics of the first position core image and the second position core image.

[0075] Specifically, the dynamic threshold method is used to segment the binary image to segment the area between the boundary and the background, so as to perform pixel point statistics of the boundary and grayscale, such as Fig. 9 (c) is shown in the figure. The purpose of image thresholding is to divide the pixel set according to the grayscale, and each subset obtained forms a region corresponding to the real scene. Each region has consistent attributes, and the adjacent regions have this consistent attribute. Such division can be achieved by selecting one or more thresholds based on the grayscale. The threshold method is a traditional image segmentation method. It has become the most basic and widely used segmentation technology in image segmentation due to its simple implementation, small amount of calculation and relatively stable performance. It has been applied to many fields.

[0076] Step S140, comparing and analyzing the pixel point differences between the first boundary pixel point statistics of the first position core image and the second boundary pixel point statistics of the second position core image according to the focusing strategy, and analyzing the pixel point differences between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core.

[0077] Specifically, the focusing strategy includes but is not limited to the traversal method and the hill climbing method. The difference is compared by comparing the data of the gray value histogram of the two pictures, and the difference between the gray value of the fiber core boundary and the gray value of the background is combined to determine the vertical movement direction and the moving step value of the fiber. The above steps are repeated cyclically, combined with the hill climbing algorithm, and the position where the fiber core boundary is focused most clearly is obtained by comparison, that is, the position where the gray value contrast between the fiber boundary and the background is the smallest.

[0078] For example, see Figure 5 , the step S140 further comprises:

[0079] Step S141, obtaining a first pixel ratio of a core boundary of the optical fiber core in the first boundary pixel point statistics and a second pixel ratio of a core boundary of the optical fiber core in the second boundary pixel point statistics.

[0080] Specifically, Fig. 9 The pixel points in (c) are counted to calculate the proportion of boundary pixel values ​​in the total pixel values ​​of the binary image.

[0081] Step S142: determining an adjustment direction of the preset step value according to a difference between the first pixel proportion and the second pixel proportion.

[0082] Specifically, Fig. 9 As shown in (a) and (c), at the initial position, the first pixel proportion of the boundary pixel is small, set to q. If the second pixel proportion at the preset step value is greater than q, it moves to the initial position. If the second pixel proportion is less than q, it moves away from the optical fiber.

[0083] For example, see Figure 6 , the step S140 further includes:

[0084] Step S140A: Counting the proportion of the boundary highlight area of ​​the first boundary pixel point statistics of the core image at the first position to the second boundary pixel point statistics of the core image at the second position.

[0085] Specifically, statistics Fig. 9 The ratio of pixels in the highlighted area in (c) to all pixels in the ROI area. The highlighted area is the area where the pixel value is greater than the preset threshold. When focusing, the ratio of the highlighted area at the boundary of the optical fiber core is the smallest.

[0086] Step S140B: using a focus strategy to analyze a statistical graph of the proportion of the boundary highlight area to obtain an optimal focus position of the optical fiber core.

[0087] Specifically, Fig.10 As shown in the figure, the density diagram is plotted. When the focus is on the middle of the fiber core, the density of the highlighted area at the edge of the fiber core is the smallest.

[0088] For example, see Figure 7 , the step S140B further comprises:

[0089] Step S140B1: If the proportion of the boundary highlight area corresponding to the first position core image is greater than the proportion of the boundary highlight area corresponding to the second position core image, it means that the position corresponding to the first position core image is the best focus position.

[0090] Step S140B2: If the proportion of the boundary highlight area corresponding to the core image at the first position is smaller than the proportion of the boundary highlight area corresponding to the core image at the second position, it indicates that the position corresponding to the core image at the second position is the best focus position.

[0091] Specifically, the farther the focusing position is from the center of the fiber core, the larger the statistical value. When the focusing position is at the center of the fiber core, the minimum statistical value is obtained. Therefore, the hill climbing method can be used to obtain the valley bottom direction, and then the optimal optical fiber core focusing position is obtained, and the depth parameter of the optical fiber core center position is obtained.

[0092] Step S160, adjusting the preset step value according to the pixel point difference to obtain the target step value with the minimum pixel point difference as the optimal focus position of the optical fiber core.

[0093] Specifically, the optical fiber core is adjusted according to the obtained adjustment direction and adjustment position.

[0094] Exemplarily, the method further includes step S170:

[0095] Step S170: if the pixel difference is greater than a preset range, repeat the following steps:

[0096] Step S100: acquiring a first position core image of an optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision.

[0097] Step S120, calculating the statistics of the core boundary pixels of the first position core image and the second position core image.

[0098] Step S140, comparing and analyzing the pixel point differences between the first boundary pixel point statistics of the first position core image and the second boundary pixel point statistics of the second position core image according to the focusing strategy, and analyzing the pixel point differences between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core.

[0099] Specifically, the purpose of the present invention is to adjust the optimal focus position, and when one adjustment is unsuccessful, multiple adjustments are performed. That is, the above steps S100-S140 are repeated cyclically, and the position where the fiber core boundary is most clearly focused is obtained by comparison in combination with the hill climbing algorithm, that is, the position where the contrast between the fiber boundary and the background gray value is the smallest.

[0100] Embodiment 2

[0101] like Figure 8 As shown, an embodiment of the present invention describes a focusing system for an optical fiber core, comprising:

[0102] The displacement platform 10 is used to fix the optical fiber fixture on which the optical fiber is placed and the amplifying element 40 .

[0103] Specifically, the displacement platform is a three-dimensional (X, Y, Z) adjustment platform, the optical fiber to be measured is fixed on the optical fiber clamp, the optical fiber clamp is fixed on the high-precision X, Y displacement platform, the X, Y displacement platform is electrically driven and controlled, and the displacement accuracy is at the sub-micron level. The X, Y platforms are installed perpendicular to each other. The optical fiber clamp is preferably a V-groove. The V-groove limits the optical fiber to ensure the position of the optical fiber when the optical fiber clamp is tightened, and ensures that the optical fiber core is within the field of view of the camera and does not exceed the field of view.

[0104] The light source 20 is placed between the optical fiber fixture and the optical fiber, and is used to provide background light for the optical fiber.

[0105] Specifically, due to the special structure of the optical fiber, back light is used as the background light source. The background light source is installed below the optical fiber sample, and the vertical line of the light source shines parallel upward.

[0106] The depth camera 30 is used to obtain the real-time position of the optical fiber and to image the optical fiber to obtain a depth image.

[0107] Specifically, a high-power objective lens is installed below the lens barrel, and a matching CCD camera (depth camera) is installed above the lens. The CCD camera is connected to the control center 50 via a network port, and the control center 50 can read the image in real time.

[0108] The amplifying element 40 is placed between the displacement platform 10 and the depth camera 30 and is used to amplify the optical fiber.

[0109] Exemplarily, the amplifying element 40 moves on the displacement platform 10 .

[0110] Specifically, the magnifying element 40 may be a high-power objective lens installed above the optical fiber. The objective lens is installed on a high-precision motion control piezoelectric ceramic structure. The piezoelectric ceramic of the Z axis can drive the high-power objective lens to move vertically along the Z axis.

[0111] The control center 50 is connected to the displacement platform 10 and the depth camera 30 , and is used to control the depth camera 30 to shoot and control the displacement platform 10 to move.

[0112] Specifically, the control center 50 includes a computer (PC host computer) and a numerical control module. The displacement platform 10 is connected by the numerical control module, and the numerical control module is controlled by the computer. The computer can send instructions to the numerical control module.

[0113] Exemplarily, the specific workflow of this embodiment is as follows: (1) Initialize the displacement platform 10, place the optical fiber on the optical fiber fixture, adjust the brightness of the background light source, manually adjust the objective lens to the height where the optical fiber core boundary is clearest, extract and analyze the depth position characteristic value, and save the characteristic value as a reference for visual discrimination. (2) During the processing, due to the limiting effect of the V-groove, after the initialization operation of the first step, the optical fiber core is guaranteed to be within the field of view, and the platform can be controlled by the control center 50 to move to any specified position. (3) Obtain the optical fiber position through the CCD, find the core area ROI through image discrimination, and the area contains the boundary of the core and does not contain interference information such as bubbles and impurities. The image is processed and the feature is read, and the characteristic value is used to discriminate the depth position index of the optical fiber core. (4) Compare the acquired characteristic index with the reference benchmark set by initialization to determine whether the best focus position is reached at this time. If the standard is met, it is prompted that the adjustment is completed. If the requirements are not met, repeat steps (2) and (3) until the requirements are met and the focus position with the clearest optical fiber core boundary is found.

[0114] The embodiment of the present invention provides a method and system for focusing the optical fiber core. By obtaining the first position core image at the initial position and the second position core image moving at a preset step value, the pixel point statistics of the core boundary are calculated, and the difference is compared through the pixel point statistics of the two images. At the same time, the vertical movement direction of the optical fiber and the target step value are determined by combining the gray value of the fiber core boundary and the gray value of the background, so as to quickly and accurately find the best focus position. The characteristics of the prior art of low positioning accuracy and slow focusing speed of the optical fiber core are overcome. The focusing process can realize a high-precision automatic focusing process without manual focusing, and accurately obtain the accurate physical position of the optical fiber core.

[0115] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0116] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method.

[0117] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for focusing an optical fiber core, characterized in that: include: Acquire a first position core image of the optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision; Calculating the core boundary pixel statistics of the first position core image and the second position core image; Comparatively analyzing pixel point differences between first boundary pixel point statistics of the fiber core image at the first position and second boundary pixel point statistics of the fiber core image at the second position according to the focusing strategy, and analyzing pixel point differences between boundary pixel points of the optical fiber core and background pixel points of the optical fiber core; According to the pixel point difference between the first boundary pixel point statistics of the core image at the first position and the second boundary pixel point statistics of the core image at the second position, as well as the pixel point difference between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core, the preset step value is adjusted to obtain the target step value with the minimum pixel point difference as the optimal focusing position of the optical fiber core.

2. The optical fiber core focusing method according to claim 1, characterized in that: The method of acquiring a first position core image of the optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision comprises: Focusing an external light source onto the core of the optical fiber by a focusing device; A first position core image of the optical fiber at an initial position and a second position core image of the optical fiber core at a preset step value are acquired based on machine vision.

3. The optical fiber core focusing method according to claim 1, characterized in that: The calculating of the core boundary pixel statistics of the first position core image and the second position core image comprises: Performing denoising processing on the first position core image and the second position core image; Performing grayscale processing on the denoised first position core image and the second position core image to obtain a binary image; The binary image is processed according to a dynamic threshold algorithm to obtain core boundary pixel statistics of the first position core image and the second position core image.

4. The optical fiber core focusing method according to claim 3, characterized in that: The grayscale processing of the denoised first position core image and the second position core image to obtain a binary image comprises: intercepting the ROI area of ​​the first position core image and the second position core image; Grayscale boundary recognition is performed on the ROI region, and grayscale processing is performed on the ROI region to obtain a binary image of the optical fiber core boundary.

5. The optical fiber core focusing method according to claim 1, characterized in that: The comparing and analyzing the pixel point difference between the first boundary pixel point statistics of the core image at the first position and the second boundary pixel point statistics of the core image at the second position according to the focusing strategy comprises: Obtaining a first pixel ratio of a core boundary of the optical fiber core in the first boundary pixel point statistics and a second pixel ratio of a core boundary of the optical fiber core in the second boundary pixel point statistics; The adjustment direction of the preset step value is determined according to the difference between the first pixel proportion and the second pixel proportion.

6. The optical fiber core focusing method according to claim 1, characterized in that: The analyzing the pixel point difference between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core includes: Counting the proportion of the boundary highlight area of ​​the first boundary pixel point statistics of the core image at the first position to the second boundary pixel point statistics of the core image at the second position; A focusing strategy is used to analyze a statistical graph of the proportion of the boundary highlight area to obtain the optimal focusing position of the optical fiber core.

7. The optical fiber core focusing method according to claim 6, characterized in that: The method of using a focus strategy to analyze a statistical graph of the proportion of a boundary highlight area to obtain an optimal focus position of the optical fiber core includes: If the proportion of the boundary highlight area corresponding to the core image at the first position is greater than the proportion of the boundary highlight area corresponding to the core image at the second position, it means that the position corresponding to the core image at the first position is the best focus position; If the proportion of the boundary highlight area corresponding to the core image at the first position is smaller than the proportion of the boundary highlight area corresponding to the core image at the second position, it means that the position corresponding to the core image at the second position is the best focus position.

8. The optical fiber core focusing method according to claim 1, characterized in that: The method further comprises: If the pixel difference is greater than the preset range, repeat the following steps: Acquire a first position core image of the optical fiber core based on an initial position and a second position core image based on a preset step value based on machine vision; Calculating the core boundary pixel statistics of the first position core image and the second position core image; According to the focusing strategy, the pixel point differences between the first boundary pixel point statistics of the fiber core image at the first position and the second boundary pixel point statistics of the fiber core image at the second position are compared and analyzed, and the pixel point differences between the boundary pixel points of the optical fiber core and the background pixel points of the optical fiber core are analyzed.

9. A focusing system for an optical fiber core, characterized in that: include: A displacement platform, used for fixing an optical fiber fixture on which an optical fiber is placed and an amplifying element; A light source, placed between the optical fiber fixture and the optical fiber, for providing background light for the optical fiber; A depth camera, used to obtain the real-time position of the optical fiber and to image the optical fiber to obtain a depth image; The amplifying element is placed between the displacement platform and the depth camera and is used to amplify the optical fiber; A control center, connected to the displacement platform and the depth camera, for controlling the depth camera to shoot and controlling the displacement platform to move; Among them, the control center is also used to obtain the first position fiber core image at the initial position and the second position fiber core image after moving through a preset step length, and by comparing and analyzing the pixel point differences between the first boundary pixel point statistics of the first position fiber core image and the second boundary pixel point statistics of the second position fiber core image, combined with the difference between the fiber core boundary grayscale value and the background grayscale value, adjust the preset step value to obtain the target step value with the minimum pixel point difference, which is used as the optimal focusing position of the fiber core.

10. The optical fiber core focusing system according to claim 9, characterized in that: The amplifying element moves on the displacement platform.

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