Cable insulation layer surface defect inspection device

Abstract

The invention relates to a cable insulation layer surface defect inspection device which comprises a cable fixing device, a laser generator, an image acquisition device and a defect identification software system, wherein the cable fixing device is used for placing a cable; the laser generator and the image acquisition device are both arranged on the cable fixing device and located above the cable; the laser generator is used for emitting laser to irradiate the surface of a cable insulation layer to form a speckle image, the image acquisition device is used for shooting the speckle image and transmitting the shot speckle image to the defect identification software system, and the defect identification software system is used for analyzing the speckle image and outputting a defect detection result. According to the invention, speckle images formed by irradiating the surface of the cable insulation layer by the laser generator can be analyzed through the defect identification software system, and a defect detection result is output, so that non-contact detection of the surface of the cable insulation layer is realized, and the surface defects of the cable insulation layer are rapidly and effectively identified; and the cable insulation layer surface defect detection efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of surface defect detection, and more specifically, to a device for inspecting surface defects of a cable insulation layer. Background Art

[0002] Power cables are an important part of the power system and are responsible for the transmission and distribution of electric energy. Cable accessories are devices that connect and protect the cable body, and are mainly divided into two categories: cable terminals and cable intermediate joints. Cable terminals are installed at the end of the cable line and have certain insulation and sealing properties to connect the cable with other electrical equipment. Cable intermediate joints are installed between cables to connect two or more cable conductors to form a continuous circuit and have certain insulation and sealing properties. Statistics from the Southern Power Grid Company show that between 2006 and 2016, non-external force failures of my country's cable system were mainly concentrated in cable accessories, of which 84% were caused by insulation interface defects caused by improper installation and construction. Cable terminals and cable intermediate joints are the parts that connect cable accessories to the cable insulation layer in the cable line, and their installation quality issues have an important impact on the operating life of the cable system.

[0003] Due to its unique mesh structure, cross-linked polyethylene cable ages slowly in a uniform electric field. However, at the cable terminal, the electric field distribution suddenly changes due to the cutting of the outer shield, which will cause electric field concentration. The insulation layer at the outer shield break will accelerate deterioration under the action of an extremely non-uniform electric field. When making cable terminals, a stress cone is set on the section of the metal shielding layer and the semi-conductive shielding layer to improve the electric field distribution here, make the electric field as uniform as possible, and achieve the purpose of delaying insulation aging. The manufacturing process (knife wounds or bubbles) and mechanical external forces are the main causes of partial discharge in the insulation layer. If the cable carries a heavy load, the cable conductor heats up, which makes it easier to accelerate the aging of the cable insulation layer. In the process of making the cross-linked polyethylene cable intermediate joint, after the outer shielding layers of the cables on both sides are stripped, the sharp corners and burrs at the ends of the insulation layer need to be removed. The ends of the insulation layer cannot be cut into cones. Sandpaper should be used to polish the ends of the insulation layer smooth, and then sandpaper should be used to polish the outer shielding layers of the cables on both sides into a smooth transition slope. Therefore, during the grinding process of the insulating layer, attention should be paid to the grinding finish of the insulating layer and possible knife scratches, bubbles or impurities on the surface.

[0004] At present, the installation of cable accessories is mainly based on the requirements of DL / T342, DL / T343 and DL / T344, and the insulation shield on the surface of the cable body is stripped: first, use a cutting tool or glass sheet to remove the insulation shield; then, in the range of 240~1500 mesh, select appropriate sandpaper from small to large to polish the insulation surface in sequence. If necessary, in order to obtain a smoother insulation surface, it is necessary to use a hot air gun for treatment. The insulation surface roughness regulations: for 110kV cables, no more than 300m; for 220kV, no more than 100m. The insulation stripping method has many steps, the process is complicated, and the skill level of the installer is required to be high. In addition, due to the changeable cable construction environment conditions, once improperly handled, it will bury a great hidden danger for the subsequent operation of the cable. If there is a lack of effective image and video recording at the construction site, it will further make it difficult to trace the cause of the accident. Therefore, how to control the construction quality of the surface roughness of the insulation layer during the installation of cable accessories has always been one of the focuses of cable accessory installation research.

[0005] Regarding the detection of cable insulation surface roughness, since traditional roughness detection instruments have certain requirements for the measurement environment and the measurement object, they cannot be applied to the on-site installation of cable joints. The existing method mainly relies on the experience of the installer to judge whether the roughness of the cable insulation surface meets its installation conditions through hand feel and side light observation. There are almost no relevant literature records on the detection method of cable insulation surface roughness at home and abroad. On the one hand, it is because the cable surface roughness is not taken seriously enough, and on the other hand, the use of professional detection methods will increase time and economic costs. In actual installation, professional instruments are rarely used to measure the cable surface roughness. Therefore, it is impossible to qualitatively judge the installation reliability of the cable after the cable is installed.

[0006] There are not many related studies on the detection of cable insulation surface roughness in the world. At present, the main technical means used is still contact detection. The contact detection method has a limited area for a single detection. At the same time, since the probe is in contact with the surface of the insulation layer, it may cause secondary damage to the insulation layer. At present, China has not developed a non-contact cable insulation surface defect detection device with mature and complete technology and generally recognized by the market. Summary of the invention

[0007] In view of this, an object of the present invention is to provide a cable insulation layer surface defect inspection device, aiming to solve the problems existing in the prior art.

[0008] According to the present invention, a device for inspecting surface defects of cable insulation layer is provided, which comprises: a cable fixing device, a laser generator, an image acquisition device and a defect recognition software system; wherein: The cable fixing device is used for placing cables; The laser generator and the image acquisition device are both arranged on the cable fixing device and located above the cable; The laser generator is used to emit laser to irradiate the surface of the cable insulation layer to form a speckle image, the image acquisition device is used to capture the speckle image and transmit the captured speckle image to the defect recognition software system, and the defect recognition software system is used to analyze the speckle image and output defect detection results.

[0009] Preferably, the defect recognition software system adopts a defect detection method of analyzing RGB three-channel intensity curves of images under broadband light illumination.

[0010] Preferably, the defect detection method of image RGB three-channel intensity curve analysis under broadband illumination comprises: Performing denoising and initialization filtering processing on the speckle image; Scan the speckle image pixels one by one in the row and column directions, and extract the intensity value curve of the RGB three channels of the pixel sequence at each row and column position; Filter the intensity value curve of the three RGB channels of each pixel sequence extracted to reduce the impact of surface contour and uneven lighting; Find and analyze the distribution of the intensity value curves of the RGB three channels of the pixel sequence at the same row and column position, identify and locate the pixel position where the singular point is located, and record it as the initial surface defect or impurity point; Traversing the distribution state of the intensity value curve of the RGB three channels of each pixel sequence in each row and column of the speckle image, identifying and recording the initial surface defect or impurity point position in the entire speckle image; The coordinate set of all initial surface defects or impurity point positions constitutes a defect connected region, the area size of each defect connected region is calculated, and the position and area information of the defect connected region whose area is greater than the threshold is output as the quantitative detection result.

[0011] Preferably, the cable fixing device comprises a base, a support seat, a vertical rod and a horizontal rod; wherein, The vertical pole is vertically arranged on the base, the horizontal pole is horizontally arranged on the vertical pole, and the laser generator and the image acquisition device are arranged on the horizontal pole; The number of the support seats is two, and the positions of the two support seats on the base are adjustable.

[0012] Preferably, the vertical pole is slidably arranged on the base along a horizontal direction, the cross bar is slidably arranged on the vertical pole along a vertical direction, and the cross bar is arranged perpendicular to the sliding direction of the vertical pole.

[0013] Preferably, a horizontal slide rail is fixedly provided on the base, a horizontal slider is slidably connected to the horizontal slide rail, and the lower end of the vertical rod is fixedly connected to the horizontal slider; A vertical slider is slidably connected to the vertical rod, a first end of the crossbar is fixedly connected to the vertical slider, and the laser generator and the image acquisition device are connected to the second end of the crossbar; Locking bolts are arranged between the horizontal slide block and the horizontal slide rail, and between the vertical slide block and the vertical rod.

[0014] Preferably, an L-shaped connecting frame is fixedly provided on the vertical slider, and the L-shaped connecting frame includes a fixed plate and a connecting plate, the fixed plate is fixedly connected to the vertical slider by bolts, the first end of the cross bar is detachably connected to the connecting plate, and the connection position of the cross bar on the connecting plate is adjustable.

[0015] Preferably, a hanging plate is provided at the second end of the cross bar, the upper end of the hanging plate is fixedly arranged on the rear side of the second end of the cross bar, the image acquisition device is fixedly installed on the front side of the second end of the cross bar, the laser generator is fixedly installed on the lower end of the hanging plate, and the angle of the laser generator on the hanging plate is adjustable.

[0016] Preferably, the support seat comprises a fixed bottom plate and two roller assemblies; wherein, The roller assembly comprises a roller bracket and a roller, wherein the roller is rotatably connected to the roller bracket, the roller bracket is detachably connected to the fixed bottom plate, and the position of the roller bracket on the fixed bottom plate is adjustable.

[0017] Preferably, the image acquisition device and the defect recognition software system are connected via WiFi.

[0018] The cable insulation layer surface defect inspection device provided by the present invention can analyze the speckle image formed by the laser generator irradiating the cable insulation layer surface through the defect recognition software system and output the defect detection result, thereby realizing non-contact detection of the cable insulation layer surface, thereby quickly and effectively identifying the cable insulation layer surface defects and improving the cable insulation layer surface defect detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0020] Figure 1 A schematic diagram of the three-dimensional structure of a cable insulation layer surface defect inspection device according to an embodiment of the present invention is shown.

[0021] Figure 2A schematic diagram of a speckle image on the surface of a cable insulation layer after filtering according to an embodiment of the present invention is shown.

[0022] Figure 3 A schematic diagram of row and column pixel scanning lines for scanning a speckle image in row and column directions according to an embodiment of the present invention is shown.

[0023] Figure 4 A schematic diagram showing an intensity value curve of three RGB channels of a single row and column pixel sequence according to an embodiment of the present invention is shown.

[0024] Figure 5 A schematic diagram showing an intensity value curve of three RGB channels of a pixel sequence after filtering according to an embodiment of the present invention is shown.

[0025] Figure 6 A schematic image diagram of the marked initial surface defects or impurity point positions and the defect connected areas formed according to an embodiment of the present invention is shown.

[0026] Figure 7 A schematic diagram of an image showing a region determined as a final surface defect or impurity point through threshold filtering according to an embodiment of the present invention.

[0027] In the figure: 1. base; 11. horizontal slide rail; 12. horizontal slider; 2. support seat; 21. fixed bottom plate; 22. roller assembly; 221. roller bracket; 222. roller; 3. vertical pole; 31. vertical slider; 4. cross bar; 41. L-shaped connecting frame; 411. fixed plate; 412. connecting plate; 42. hanging plate; 5. image acquisition device; 6. laser generator. DETAILED DESCRIPTION

[0028] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0029] The present invention provides a device for inspecting surface defects of cable insulation layer, see Figure 1 The cable insulation layer surface defect inspection device comprises: a cable fixing device, a laser generator 6, an image acquisition device 5 and a defect recognition software system (not shown in the figure); wherein the cable fixing device is used to place the cable; the laser generator 6 and the image acquisition device 5 are both arranged on the cable fixing device and located above the cable; the laser generator 6 is used to emit laser to irradiate the surface of the cable insulation layer to form a speckle image, the image acquisition device 5 is used to shoot the speckle image and transmit the shot speckle image to the defect recognition software system, and the defect recognition software system is used to analyze the speckle image and output the defect detection result.

[0030] Since the cable insulation layer surface defect inspection device adopts a defect recognition software system to analyze the speckle image on the cable insulation layer surface and output the defect detection result, it does not need to directly contact the cable insulation layer surface during detection, thereby realizing non-contact detection of the cable insulation layer surface. Compared with the existing contact detection method, the defect inspection device will not cause secondary damage to the cable insulation layer surface, and can quickly and effectively identify the cable insulation layer surface defects, thereby improving the cable insulation layer surface defect detection efficiency.

[0031] See also Figure 1 , the cable fixing device includes a base 1, a support seat 2, a vertical pole 3 and a cross bar 4; wherein the vertical pole 3 is vertically arranged on the base 1, the cross bar 4 is transversely arranged on the vertical pole 3, and the laser generator 6 and the image acquisition device 5 are arranged on the cross bar 4; the number of the support seats 2 is two, and the positions of the two support seats 2 on the base 1 are adjustable. The cable to be detected is placed on the two support seats 2, and the two support seats 2 support the cable. Specifically, the two support seats 2 are spaced apart along the length direction of the base 1, and by adjusting the distance between the two support seats 2, cables of different lengths can be supported.

[0032] In this embodiment, the support seat 2 includes a fixed base plate 21 and two roller assemblies 22; wherein the roller assembly 22 includes a roller bracket 221 and a roller 222, wherein the roller 222 is rotatably connected to the roller bracket 221, wherein the roller bracket 221 is detachably connected to the fixed base plate 21, and the position of the roller bracket 221 on the fixed base plate 21 is adjustable. By adjusting the distance between the two roller brackets 221, the support seat 2 can support cables of different diameters. In this embodiment, the roller bracket 221 includes a bracket base plate and two bracket vertical plates, wherein the two bracket vertical plates are vertically connected to the bracket base plate, and the roller 222 is connected to the two bracket vertical plates through a rotating shaft; a fixing bolt hole is provided on the bracket base plate of the roller bracket 221, and a plurality of threaded holes are provided on the fixed base plate 21, wherein the position of the roller bracket 221 on the fixed base plate 21 can be adjusted by passing the fixing bolt hole on the bracket base plate through the bolt and connecting with the threaded holes at different positions on the fixed base plate 21.

[0033] Further, the vertical pole 3 is slidably arranged on the base 1 along the horizontal direction, and the cross bar 4 is slidably arranged on the vertical pole 3 along the vertical direction, and the cross bar 4 is arranged perpendicular to the sliding direction of the vertical pole 3. Specifically, the sliding direction of the vertical pole 3 is arranged along the length direction of the base 1, that is, the sliding direction of the vertical pole 3 is consistent with the length direction of the cable when it is placed, and by adjusting the position of the vertical pole 3 on the base 1, the cross bar 4 arranged on the vertical pole 3 can move with the vertical pole 3, so that the laser generator 6 and the image acquisition device 5 arranged on the cross bar 4 move along the length direction of the base 1 to irradiate different positions on the surface of the cable insulation layer and collect speckle images; by adjusting the position of the cross bar 4 on the vertical pole 3, the laser generator 6 and the image acquisition device 5 arranged on the cross bar 4 move along the height direction to adjust to a suitable height that meets the detection requirements. In this embodiment, a horizontal slide rail 11 is fixedly provided on the base 1, and a horizontal slider 12 is slidably connected to the horizontal slide rail 11, and the lower end of the vertical rod 3 is fixedly connected to the horizontal slider 12; a vertical slider 31 is slidably connected to the vertical rod 3, and the first end of the cross bar 4 is fixedly connected to the vertical slider 31, and the laser generator 6 and the image acquisition device 5 are connected to the second end of the cross bar 4; locking bolts are provided between the horizontal slider 12 and the horizontal slide rail 11, and between the vertical slider 31 and the vertical rod 3. Specifically, the horizontal slide rail 11 and the horizontal slider 12 are respectively provided with a matching first protrusion and a first slide groove, and the vertical rod 3 and the vertical slider 31 are respectively provided with a matching second protrusion and a second slide groove, and the first protrusion and the second protrusion can be dovetail-shaped protrusions, so that the horizontal slider 12 and the vertical slider 31 will not be separated when sliding; bolt through holes are provided between the first slide groove of the horizontal slider 12 and the outer side surface of the horizontal slider 12, and between the second slide groove of the vertical slider 31 and the outer side surface of the vertical slider 31, and the locking bolt is screwed on the bolt through hole, and the locking bolt is screwed on the first protrusion or the second protrusion, so as to realize the locking and fixing of the horizontal slider 12 and the vertical slider 31. That is, after the vertical rod 3 and the horizontal rod 4 are adjusted to the appropriate position, the positions of the vertical rod 3 and the horizontal rod 4 are respectively locked by the locking bolt.

[0034] Furthermore, an L-shaped connecting frame 41 is fixedly provided on the vertical slider 31, and the L-shaped connecting frame 41 includes a fixing plate 411 and a connecting plate 412. The fixing plate 411 is fixedly connected to the vertical slider 31 by bolts, and the first end of the cross bar 4 is detachably connected to the connecting plate 412, and the connection position of the cross bar 4 on the connecting plate 412 is adjustable. In this embodiment, two groups of bolt holes are provided on the connecting plate 412 of the L-shaped connecting frame 41, and the two groups of bolt holes are arranged at a preset distance in the horizontal direction, and each group of bolt holes includes two upper and lower bolt holes. The cross bar 4 is a plate-like structure, and the first end of the cross bar 4 is provided with multiple groups of oblong holes, and the multiple groups of oblong holes are arranged at a preset distance in the horizontal direction. The spacing between two adjacent groups of oblong holes is consistent with the spacing between the two groups of bolt holes on the connecting plate 412, and each group of oblong holes includes two upper and lower oblong holes. The connecting plate 412 and the cross bar 4 are fixedly connected by bolts passing through the bolt holes and the oblong holes. The position of the cross bar 4 in the width direction of the base 1 can be adjusted through the oblong holes on the cross bar 4, thereby adjusting the position of the laser generator 6 and the image acquisition device 5 arranged on the cross bar 4, so that during detection, the incident light direction of the laser emitted by the laser generator 6 can be perpendicular to the busbar incident on the outer circle of the cable insulation layer.

[0035] Furthermore, a hanging plate 42 is provided at the second end of the crossbar 4, the upper end of the hanging plate 42 is fixedly arranged at the rear side of the second end of the crossbar 4, the image acquisition device 5 is fixedly installed at the front side of the second end of the crossbar 4, and the laser generator 6 is fixedly installed at the lower end of the hanging plate 42, and the angle of the laser generator 6 on the hanging plate 42 is adjustable. Specifically, the hanging plate 42 is arranged perpendicular to the crossbar 4, and the laser generator 6 is arranged below the image acquisition device 5 after being installed on the hanging plate 42; the angle of the laser generator 6 is adjustable, and when performing defect detection on the cable, the angle of the laser generator 6 can be adjusted so that the incident angle of the laser emitted by the laser generator 6 on the surface of the cable insulation layer meets the test requirements. For example, a rotating shaft can be rotatably arranged on the hanging plate 42, the laser generator 6 is fixedly connected to the rotating shaft, a stud is arranged at one end of the rotating shaft, and the stud passes through the hanging plate 42 and is locked and fixed by a nut.

[0036] In this embodiment, the image acquisition device 5 is an MVC1000MF industrial camera, and the laser generator 6 is an adjustable constant voltage laser. The image acquisition device 5 is connected to the defect recognition software system via WiFi, and the speckle image captured by the image acquisition device 5 is wirelessly transmitted to the remote defect recognition software system via WiFi transmission.

[0037] Furthermore, the defect recognition software system adopts a defect detection method of analyzing the RGB three-channel intensity curve of the image under broadband light illumination, and finally integrates and outputs the defect detection results.

[0038] Specifically, the defect detection method of image RGB three-channel intensity curve analysis under broadband illumination includes: The speckle image is subjected to denoising and initialization filtering. Figure 2 As shown in the figure, it is the speckle image of the cable insulation layer surface after filtering. Scan the speckle image pixels one by one in the row and column direction, and extract the intensity value curve of the RGB three channels of the pixel sequence at each row and column position. Figure 3 and Figure 4 The figures are respectively a schematic diagram of a row and column pixel scanning line and a schematic diagram of an intensity value curve of the RGB three channels of a single row and column pixel sequence.

[0039] The intensity value curve of the RGB three channels of each pixel sequence extracted is filtered to reduce the influence of surface contour and uneven lighting. Figure 5 , which is a schematic diagram of the intensity value curve of the RGB three channels of a pixel sequence after filtering.

[0040] Find and analyze the distribution of the intensity value curves of the RGB three channels of the pixel sequence at the same row and column position, identify and locate the pixel position of the singular point, and record it as the initial surface defect or impurity point. In general, when the surface of the cable insulation layer is polished and pollution-free, the RGB three-color intensity value curves at the same row and column position are in a normal parallel and stable fluctuation state without intersection. When there are special conditions such as polished surface defects, adsorbed impurities and color boundaries, the RGB three-color intensity curves at the same row and column position will have singular points such as intersections, gradient mutations and missing positions, such as Figure 5 The singular points shown in .

[0041] The distribution state of the intensity value curve of the RGB three channels of each pixel sequence in each row and column of the speckle image is traversed to identify and record the initial surface defect or impurity point position in the entire speckle image.

[0042] The coordinate set of all initial surface defects or impurity point positions constitutes a defect connected region, the area size of each defect connected region is calculated, and the position and area information of the defect connected region with an area greater than the threshold is output as the quantitative detection result. Specifically, according to the specified defect or attached impurity size standard and combined with the imaging magnification, a judgment threshold for the area of ​​the surface defects or impurity points of the identified image is given, and the defect connected regions with an area less than the threshold are removed, and the position and area information of the remaining defect connected regions are output as the quantitative detection result. See Figure 6 and Figure 7 , Figure 6 The image diagram of the marked initial surface defects or impurity point positions and the defect connected areas formed. Figure 7This is a schematic diagram of an image of an area determined to be a final surface defect or impurity point through threshold filtering.

[0043] Finally, the characteristic value (the location and area information of the defect connected area whose area is greater than the threshold) is used to determine whether it is a defect that affects the operation of the cable.

[0044] In summary, the cable insulation layer surface defect inspection device provided by the present invention can analyze the speckle image formed by the laser generator irradiating the cable insulation layer surface through the defect recognition software system and output the defect detection result, thereby realizing non-contact detection of the cable insulation layer surface, thereby quickly and effectively identifying the cable insulation layer surface defects and improving the cable insulation layer surface defect detection efficiency.

[0045] The present invention adopts quantitative criteria to replace the existing mainstream experience construction. Different from the existing roughness detectors on the market, the defect inspection device also adopts a non-contact detection method to quickly and effectively identify the surface defects of the cable insulation layer, rather than obtaining the surface roughness of the cable insulation layer through contact detection. All detection pictures can be retained to ensure that the installation process of cable accessories can be traced.

[0046] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0047] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. A cable insulation surface defect inspection device, characterized in that: include: Cable fixing device, laser generator, image acquisition device and defect recognition software system; among which, The cable fixing device is used for placing cables; The laser generator and the image acquisition device are both arranged on the cable fixing device and located above the cable; The laser generator is used to emit laser to irradiate the surface of the cable insulation layer to form a speckle image, the image acquisition device is used to capture the speckle image and transmit the captured speckle image to the defect recognition software system, and the defect recognition software system is used to analyze the speckle image and output defect detection results.

2. The cable insulation layer surface defect inspection device according to claim 1, characterized in that: The defect recognition software system adopts a defect detection method based on RGB three-channel intensity curve analysis of images under broadband light illumination.

3. The cable insulation layer surface defect inspection device according to claim 2, characterized in that: The defect detection method of image RGB three-channel intensity curve analysis under broadband illumination includes: Performing denoising and initialization filtering processing on the speckle image; Scan the speckle image pixels one by one in the row and column directions, and extract the intensity value curve of the RGB three channels of the pixel sequence at each row and column position; Filter the intensity value curve of the three RGB channels of each pixel sequence extracted to reduce the impact of surface contour and uneven lighting; Find and analyze the distribution of the intensity value curves of the RGB three channels of the pixel sequence at the same row and column position, identify and locate the pixel position where the singular point is located, and record it as the initial surface defect or impurity point; Traversing the distribution state of the intensity value curve of the RGB three channels of each pixel sequence in each row and column of the speckle image, identifying and recording the initial surface defect or impurity point position in the entire speckle image; The coordinate set of all initial surface defects or impurity point positions constitutes a defect connected region, the area size of each defect connected region is calculated, and the position and area information of the defect connected region whose area is greater than the threshold is output as the quantitative detection result.

4. The cable insulation layer surface defect inspection device according to claim 1, characterized in that: The cable fixing device comprises a base, a support seat, a vertical rod and a horizontal rod; wherein, The vertical pole is vertically arranged on the base, the horizontal pole is horizontally arranged on the vertical pole, and the laser generator and the image acquisition device are arranged on the horizontal pole; The number of the support seats is two, and the positions of the two support seats on the base are adjustable.

5. The cable insulation layer surface defect inspection device according to claim 4, characterized in that: The vertical rod is slidably arranged on the base along a horizontal direction, and the cross bar is slidably arranged on the vertical rod along a vertical direction, and the cross bar is arranged perpendicular to the sliding direction of the vertical rod.

6. The cable insulation layer surface defect inspection device according to claim 5, characterized in that: A horizontal slide rail is fixedly arranged on the base, a horizontal slider is slidably connected to the horizontal slide rail, and the lower end of the vertical rod is fixedly connected to the horizontal slider; A vertical slider is slidably connected to the vertical rod, a first end of the crossbar is fixedly connected to the vertical slider, and the laser generator and the image acquisition device are connected to the second end of the crossbar; Locking bolts are arranged between the horizontal slide block and the horizontal slide rail, and between the vertical slide block and the vertical rod.

7. The cable insulation layer surface defect inspection device according to claim 6, characterized in that: An L-shaped connecting frame is fixedly provided on the vertical slider, and the L-shaped connecting frame includes a fixing plate and a connecting plate. The fixing plate is fixedly connected to the vertical slider by bolts, the first end of the cross bar is detachably connected to the connecting plate, and the connection position of the cross bar on the connecting plate is adjustable.

8. The cable insulation layer surface defect inspection device according to claim 6, characterized in that: A hanging plate is provided at the second end of the cross bar, the upper end of the hanging plate is fixedly arranged on the rear side of the second end of the cross bar, the image acquisition device is fixedly installed on the front side of the second end of the cross bar, the laser generator is fixedly installed on the lower end of the hanging plate, and the angle of the laser generator on the hanging plate is adjustable.

9. The cable insulation layer surface defect inspection device according to claim 4, characterized in that: The support seat includes a fixed bottom plate and two roller assemblies; wherein, The roller assembly comprises a roller bracket and a roller, wherein the roller is rotatably connected to the roller bracket, the roller bracket is detachably connected to the fixed bottom plate, and the position of the roller bracket on the fixed bottom plate is adjustable.

10. The cable insulation layer surface defect inspection device according to claim 1, characterized in that: The image acquisition device is connected to the defect recognition software system via WiFi.

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