Method and device for manufacturing fiber-reinforced resin composite pipe based on image evaluation

Abstract

The present application relates to a manufacturing method and device for fiber-reinforced resin composite pipes based on image evaluation, which includes the inner layer weaving stage of the composite pipe, the middle layer weaving stage of the composite pipe, the outer layer weaving stage of the composite pipe, and the surface image evaluation stage of the composite pipe. Based on the high-temperature ceramizable modified silicone rubber fiber as the weaving material of the composite pipe, the surface performance of the composite pipe is improved. In addition, during the image evaluation process, the segmented image acquisition and stitching technology is adopted to completely obtain the 360° circumferential surface image of the composite pipe; combined with multi-directional feature extraction, the sliding window sampling is carried out in both the axial and circumferential directions respectively, and based on the relative entropy algorithm calculation, the probability distribution difference of the image segments is converted into a numerical index, which can quantitatively characterize the uniformity of different regions, and by constructing a similarity matrix and combining the mean deviation analysis, the abnormal region can be located to a single sliding window, realizing the precise positioning of the defect position and improving the comprehensiveness of defect recognition.

Description

Technical Field

[0001] The present application relates to the technical field of composite pipe manufacturing, and specifically relates to a method and device for manufacturing a fiber-reinforced resin composite pipe based on image evaluation. Background Art

[0002] As a high-performance structural member woven from multiple layers of materials, composite pipes are widely used in fields such as aerospace, petrochemical, and high-end equipment manufacturing. Their surface quality (such as fiber distribution uniformity, interlayer bonding strength, shear resistance, specific strength performance, etc.) directly affects the mechanical properties and service life of the product.

[0003] Currently, in the traditional composite pipe manufacturing process, a large amount of metal fibers are generally used to enhance the strength of the composite pipe. Although it can provide high mechanical strength, there are problems such as insulation and electromagnetic compatibility defects, and poor interfacial compatibility. With the demand for multifunctional composite pipe materials in modern industry, in some fields, the material is required to have high insulation and extremely high fire resistance, while the traditional metal fiber system cannot meet both requirements simultaneously.

[0004] In addition, the existing composite pipe manufacturing process cannot monitor the fiber distribution uniformity in real time during the multi-layer weaving process. Uneven fiber distribution is the main cause of interfacial defects. Once it occurs, it will have a great impact on the surface performance of the composite pipe. Therefore, it is necessary to improve the surface material of the composite pipe and conduct real-time image evaluation on the surface. Summary of the Invention

[0005] To overcome the deficiencies of the above-mentioned prior art, the present application provides a method and device for manufacturing a fiber-reinforced resin composite pipe based on image evaluation, and specifically adopts the following technical solutions:

[0006] A method for manufacturing a fiber-reinforced resin composite pipe based on image evaluation, characterized in that the method comprises the following steps:

[0007] Weave the inner layer of the composite pipe through fiber weaving technology;

[0008] Weave the intermediate layer of the composite pipe on the surface of the inner layer of the composite pipe through fiber weaving technology;

[0009] Weave the outer layer of the composite pipe on the surface of the intermediate layer of the composite pipe through fiber weaving technology;

[0010] Among them, when weaving the inner layer, intermediate layer, and outer layer of the composite pipe, image evaluation is respectively performed on the surface of the composite pipe:

[0011] Use an image acquisition device to segmentally acquire images of the current circumferential surface of the composite pipe to obtain the surface image of the composite pipe;

[0012] Perform image preprocessing on the collected surface image of the composite pipe; the image preprocessing includes image correction, image stitching, and grayscale conversion;

[0013] Use a sliding window method to slide the preprocessed surface image of the composite pipe along a preset direction respectively to obtain a number of image segments; the preset direction includes a first direction corresponding to the axial direction of the composite pipe and a second direction corresponding to the circumferential direction of the composite pipe;

[0014] Calculate the similarity between adjacent image segments based on the relative entropy algorithm:

[0015] ;

[0016] where is the similarity between adjacent image segments P and Q; is the distribution probability of image segment P; is the distribution probability of image segment Q;

[0017] Obtain the similarity matrix of the surface image of the composite pipe according to the similarity calculation results;

[0018] Judge the uniformity and abnormal positions of the current circumferential surface of the composite pipe based on the similarity matrix.

[0019] Optionally: The steps of performing image preprocessing on the collected surface image of the composite pipe include:

[0020] Obtain the internal parameter data of the image acquisition device and the radius of the current composite pipe respectively; the internal parameter data includes at least the focal length, the principal point coordinates, and the distortion parameters;

[0021] Establish a cylindrical coordinate system based on the radius and the axis position of the composite pipe;

[0022] Map the pixel coordinates of the surface image of the composite pipe collected by different image acquisition devices into the cylindrical coordinate system:

[0023] ;

[0024] where is the angle of the pixel coordinate in the cylindrical coordinate system; is the height of the pixel coordinate in the cylindrical coordinate system; is the principal point coordinate of the surface image of the composite pipe in the horizontal direction; is the principal point coordinate of the surface image of the composite pipe in the vertical direction; is the radius of the composite pipe;

[0025] Convert the position of the pixel coordinate in the cylindrical coordinate system into a planar unfolded coordinate :

[0026] 。

[0027] Optionally, the step of performing image preprocessing on the collected surface image of the composite tube includes:

[0028] Using a feature extraction algorithm to extract feature points from the surface image of the composite tube after planar unfolding;

[0029] Based on feature point matching, searching for matching point pairs among the feature points of the surface images of the composite tube collected by adjacent image acquisition devices;

[0030] According to the matching point pairs, using the RANSAC algorithm to calculate and obtain the homography matrix between the surface images of the composite tube collected by adjacent image acquisition devices;

[0031] According to the homography matrix between adjacent surface images of the composite tube, performing geometric transformation on the surface images of the composite tube to align adjacent surface images of the composite tube;

[0032] Based on the aligned adjacent surface images of the composite tube, finding the overlapping area to obtain the image fusion area;

[0033] Based on an image fusion algorithm, splicing and combining the image fusion areas of adjacent surface images of the composite tube to obtain a complete and unfolded circumferential surface image of the composite tube.

[0034] Optionally, the step of sliding the preprocessed surface image of the composite tube along a preset direction in a sliding window manner includes:

[0035] Determining the sliding window size and the sliding step length according to the diameter of the composite tube and the image resolution;

[0036] Based on the first direction and the second direction, the sliding window slides respectively according to the set sliding step length to obtain a number of image segments;

[0037] Arranging a number of image segments in a matrix distribution according to the acquisition positions of the image segments to obtain an image segment matrix.

[0038] Optionally, the step of obtaining the similarity matrix of the surface image of the composite tube according to the similarity calculation result includes:

[0039] Based on the image segment matrix, calculating the similarity of adjacent image segments respectively in the first direction and the second direction to obtain the similarity matrix D 1 in the first direction and the similarity matrix D 2:

[0040] ;

[0041] where Denote the image segment at the n-th row and m-th column; is the image segment along the first direction and the image segment the similarity between; is the image segment along the second direction and the image segment the similarity between.

[0042] Optionally: The step of judging the uniformity of the current circumferential surface of the composite pipe and the abnormal position based on the similarity matrix includes:

[0043] Calculate the means of the elements in the first similarity matrix and the second similarity matrix respectively;

[0044] Calculate the difference between the element at each position in the first similarity matrix and the corresponding mean value and calculate the difference between the element at each position in the first similarity matrix and the corresponding mean value;

[0045] Judge respectively whether the absolute value of the calculated difference in the first similarity matrix and the second similarity matrix exceeds a preset threshold:

[0046] When the absolute value of the calculated difference is greater than or equal to the preset threshold, judge that the corresponding element in the corresponding similarity matrix is abnormal, and obtain the corresponding abnormal image segment position according to the position of the abnormal element in the corresponding similarity matrix;

[0047] When the absolute value of the calculated difference is less than the preset threshold, judge that there is no abnormality.

[0048] Optionally: The inner layer is woven from a twisted fiber bundle mixed with heat-resistant ceramizable modified silicone rubber fiber and glass fiber impregnated with resin; the middle layer includes at least two layers, and the middle layer is woven from a twisted fiber bundle mixed with heat-resistant ceramizable modified silicone rubber fiber and glass fiber impregnated with resin; the outer layer includes a first outer layer and a second outer layer on the surface of the first outer layer, the first outer layer is woven from multiple strands of glass fiber wire impregnated with resin, and the second outer layer is woven from a twisted fiber bundle mixed with heat-resistant ceramizable modified silicone rubber fiber and glass fiber impregnated with resin;

[0049] Wherein the preparation method of the heat-resistant ceramizable modified silicone rubber fiber includes the following steps:

[0050] (1) Weigh a certain amount of methyl chlorosiloxane rubber, heat it and immerse it in cyclohexane solvent for pretreatment to obtain pretreated methyl chlorosiloxane rubber;

[0051] (2) Dissolve triethoxysilane in ethanol, add ammonia water to adjust the pH to 4 - 5 to form a hydrolysis solution. Add polydimethylsiloxane to the hydrolysis solution, disperse the polydimethylsiloxane by ultrasonic treatment, and then add nanoscale aluminum nitride and stir to disperse the aluminum nitride to obtain a silicon nitride precursor solution;

[0052] (3) Mix the silicon nitride precursor solution obtained in step (2) with the pretreated methyl chlorosiloxane rubber obtained in step (1), heat the mixture to 250 - 300 °C, and keep the temperature for 2 - 4 hours to obtain a ceramic precursor material;

[0053] (4) Heat the ceramic precursor material to a molten state, extrude it to form fibers, cool and solidify the fibers, and then perform high-temperature sintering on the fibers;

[0054] (5) Spray a silica dispersion liquid on the surface of the fibers sintered in step (4), and obtain the high-temperature ceramizable modified silicone rubber fibers after drying and solidifying.

[0055] Optionally: The specific pretreatment process in step (1) is as follows: Heat the methyl chlorosiloxane rubber to 80 - 100 °C, immerse the heated methyl chlorosiloxane rubber in a cyclohexane solvent, stir for 10 - 15 minutes, and then perform vacuum degassing to obtain the pretreated methyl chlorosiloxane rubber.

[0056] Optionally: The mass ratio of the triethoxysilane to ethanol in step (2) is 1:3 - 5, the mass of the polydimethylsiloxane is 1 - 5% of the hydrolysis solution, and the mass of the nanoscale aluminum nitride is 2 - 5% of the hydrolysis solution; the mass ratio of the silicon nitride precursor solution to the pretreated methyl chlorosiloxane rubber in step (3) is 1:5 - 10; the temperature of the high-temperature sintering in step (4) is 1200 - 1300 °C and is maintained for 2 - 3 hours; the silica dispersion liquid in step (5) is a mixture of silica and ethanol, and the mass-volume ratio of silica to ethanol is 1 g:5 - 10 mL.

[0057] Optionally: The preparation method of the twisted fiber bundle of the high-temperature ceramizable modified silicone rubber fiber impregnated with resin and mixed with glass fiber includes the following steps:

[0058] (1) Mix the high-temperature ceramizable modified silicone rubber fibers prepared above with glass fibers according to a mass ratio of 1:1 - 3. After mixing, wind the two fiber bundles together by twisting technology to form a twisted fiber bundle;

[0059] (2) Immerse the twisted fiber bundle in an epoxy resin impregnating solution, soak the fiber bundle to ensure that the fiber bundle is completely penetrated by the resin. After the fiber bundle is infiltrated with the resin, heat and cure and dry it to obtain the twisted fiber bundle of the high-temperature ceramizable modified silicone rubber fiber impregnated with resin and mixed with glass fiber.

[0060] In addition, the present application also discloses a manufacturing device for fiber-reinforced resin composite pipes based on image evaluation, and the device includes:

[0061] An inner layer weaving unit for obtaining the inner layer of the composite pipe by fiber weaving technology;

[0062] An intermediate layer weaving unit for obtaining the intermediate layer of the composite pipe by fiber weaving technology on the surface of the inner layer of the composite pipe;

[0063] An outer layer weaving unit for obtaining the outer layer of the composite pipe by fiber weaving technology on the surface of the intermediate layer of the composite pipe;

[0064] An image evaluation unit for respectively performing image evaluation on the surface of the composite pipe when weaving the inner layer, intermediate layer, and outer layer of the composite pipe:

[0065] Using an image acquisition device to segmentally acquire images of the current circumferential surface of the composite pipe to obtain the surface image of the composite pipe;

[0066] Performing image preprocessing on the acquired surface image of the composite pipe; the image preprocessing includes image correction, image stitching, and grayscale conversion;

[0067] Sliding the preprocessed surface image of the composite pipe along a preset direction in a sliding window manner to obtain a number of image segments; the preset directions include a first direction corresponding to the axial direction of the composite pipe and a second direction corresponding to the circumferential direction of the composite pipe;

[0068] Calculating the similarity between adjacent image segments based on the relative entropy algorithm:

[0069] ;

[0070] where is the similarity between adjacent image segments P and Q; is the distribution probability of image segment P; is the distribution probability of image segment Q;

[0071] Obtaining the similarity matrix of the surface image of the composite pipe according to the similarity calculation result;

[0072] Judging the uniformity and abnormal positions of the current circumferential surface of the composite pipe based on the similarity matrix.

[0073] Beneficial effects

[0074] The technical solution of the present application has obtained the following beneficial effects:

[0075] (1) The manufacturing method of the fiber-reinforced resin composite pipe in this application adopts the segmented image acquisition and stitching technology, breaking through the limitations of traditional single-point detection, and can completely obtain the 360° circumferential surface image of the composite pipe to ensure no blind spots in detection; and based on the multi-directional feature extraction method, it can slide the window for sampling in both the axial and circumferential directions respectively, and simultaneously capture the feature differences of the composite pipe surface in the length direction and the circumferential direction, improving the comprehensiveness of defect recognition.

[0076] (2) The manufacturing method of the fiber-reinforced resin composite pipe in this application is based on the similarity calculation of the relative entropy algorithm, which converts the probability distribution difference of the image fragments into a numerical index, and can quantitatively characterize the uniformity of different regions. Compared with the traditional threshold segmentation method, it has higher sensitivity to subtle defects (such as 0.1mm fiber misalignment); and by constructing a similarity matrix and combining the mean deviation analysis, the abnormal region can be located to a single sliding window, realizing centimeter-level precise positioning of the defect position.

[0077] (3) The manufacturing method of the fiber-reinforced resin composite pipe in this application can automatically generate the uniformity evaluation result by thresholding the similarity matrix, and output the abnormal position, providing an intuitive basis for real-time quality monitoring in the production process, with an efficiency improvement of more than 80% compared to manual visual inspection.

[0078] (4) The manufacturing method of the fiber-reinforced resin composite pipe in this application uses high-temperature ceramizable modified silicone rubber fiber as the braided material of the composite pipe, which has excellent fire prevention, anti-ablative and high-temperature resistance properties. Through high-temperature sintering, the modified silicone rubber fiber forms a high-temperature resistant ceramic layer in a high-temperature environment, making it have extremely strong thermal stability at high temperatures. The chemical stability and oxidation resistance of the silicone rubber matrix enable the fiber to effectively resist combustion and oxidation under extreme high-temperature conditions, and at the same time, the ablation rate is low, and it can maintain good structural integrity. In addition, during the combustion process, the combustion characteristics of the modified silicone rubber are low smoke, non-toxic, and the flame propagation speed is slow, further improving the fire prevention and disaster prevention performance. Description of the Drawings

[0079] Figure 1 It is a flowchart of the manufacturing method of the fiber-reinforced resin composite pipe in the embodiment of this application.

[0080] Figure 2 It is a schematic diagram of the process of intercepting image fragments using a sliding window in the embodiment of this application.

[0081] Figure 3 It is a schematic diagram of the process of obtaining the first similarity matrix from the image fragment matrix in the embodiment of this application.

[0082] Figure 4 It is a schematic diagram of the process of obtaining the second similarity matrix from the image fragment matrix in the embodiment of this application.

[0083] Figure 5 This is a schematic structural diagram of a fiber - reinforced resin composite pipe manufacturing device in an embodiment of the present application.

[0084] Figure 6 This is a structural diagram of an electronic device in an embodiment of the present application. Detailed implementation manners

[0085] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application and cannot be used to limit the protection scope of the present application. It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanations for the present application.

[0086] Due to its excellent properties such as high strength, light weight, and corrosion resistance, fiber composite pipes have been widely used in many fields such as petrochemical industry, aerospace, and construction engineering. Currently, the quality of traditional composite pipes is affected by various factors, including fiber materials, weaving processes, and impregnation effects. To ensure the quality stability and reliability of composite pipes, the present application proposes a method and device for manufacturing fiber - reinforced resin composite pipes based on image evaluation. By introducing a high - temperature ceramifiable modified silicone rubber fiber material during the manufacturing process of composite pipes and combining image evaluation technology, the surface quality of composite pipes is monitored in real - time, effectively improving the strength and quality of composite pipe products.

[0087] Combined with Figure 1 As shown, the method for manufacturing a fiber - reinforced resin composite pipe based on image evaluation in the present application specifically includes the following steps:

[0088] Inner - layer weaving: The inner layer of the composite pipe is woven through fiber weaving technology; among them, the inner - layer material preferably uses a twisted fiber bundle mixed with high - temperature ceramifiable modified silicone rubber fiber impregnated with resin and glass fiber. The high - temperature ceramifiable modified silicone rubber fiber endows the composite pipe with good flexibility, high - temperature resistance, and chemical corrosion resistance, while the glass fiber provides high - strength support. Before weaving, the fiber bundle needs to be pretreated by placing it under specific temperature and humidity conditions for a period of time to make the performance of the fiber bundle more stable. During the weaving process, generally two - dimensional or three - dimensional weaving processes are used, and according to the design requirements of the composite pipe, parameters such as weaving angle and weaving density are precisely controlled. During the weaving process, it is necessary to ensure that the fiber bundles are evenly distributed to avoid problems such as fiber bundle overlap and excessive gaps.

[0089] Intermediate layer weaving: The intermediate layer of the composite pipe is obtained by fiber weaving technology on the inner surface of the inner layer of the composite pipe; in this embodiment, the intermediate layer includes at least two layers, and the intermediate layer uses a twisted fiber bundle mixed with heat-resistant porcelainizable modified silicone rubber fiber impregnated with resin and glass fiber; the heat-resistant porcelainizable modified silicone rubber fiber can be transformed into ceramic material under high-temperature environment, enhancing the high-temperature resistance and fire resistance of the composite pipe. The weaving process of the intermediate layer is similar to that of the inner layer. According to the mechanical property requirements of the composite pipe, the weaving angle and density can be adjusted. When weaving adjacent two intermediate layers, a cross-weaving method is adopted to improve the overall strength and impact resistance of the composite pipe. Specifically, in this embodiment, from the inside to the outside, the first intermediate layer is formed by continuously winding a twisted fiber bundle mixed with heat-resistant porcelainizable modified silicone rubber fiber impregnated with resin and glass fiber circumferentially on the inner layer, then axially laid glass fiber impregnated with resin along the pipe axis on the first intermediate layer, and then continuously wound a layer of glass fiber impregnated with resin circumferentially to form the second intermediate layer. After weaving, the quality of the intermediate layer needs to be inspected to observe the distribution of the fiber bundles, and adjustments should be made in time if there are any abnormalities.

[0090] Outer layer weaving: The outer layer of the composite pipe is obtained by fiber weaving technology on the surface of the intermediate layer of the composite pipe; the outer layer includes a first outer layer and a second outer layer located on the surface of the first outer layer. The first outer layer uses multiple strands of glass fiber wire impregnated with resin, mainly providing the surface hardness and wear resistance of the composite pipe; the second outer layer uses a twisted fiber bundle mixed with heat-resistant porcelainizable modified silicone rubber fiber impregnated with resin and glass fiber to further enhance the fire resistance and weather resistance of the composite pipe. In this embodiment, the first outer layer is woven into a cylindrical structure by applying three-dimensional weaving technology with multiple strands of glass fiber wire impregnated with resin, and the whole first outer layer is integral, without overlap in the whole layer structure, no edge stress defect, and the fiber space distribution is uniform and fine. In particular, in the space of multiple strands of glass fiber wire, it should be ensured that there are more than 3 strands at the intersection of the glass fiber wires and they extend in 3 directions, so as to greatly enhance the stress-bearing capacity in all directions and improve the anti-shear performance and specific strength performance of the pipeline. The second outer layer is formed by using a twisted fiber bundle mixed with heat-resistant porcelainizable modified silicone rubber fiber impregnated with resin and glass fiber and combining two-dimensional or three-dimensional weaving technology.

[0091] Image evaluation: Since it is necessary to ensure the uniform distribution of the fiber bundles in each layer of the composite pipe during the weaving process, in this application, when weaving the inner layer, intermediate layer and outer layer of the composite pipe, the surface of the composite pipe is respectively subjected to image evaluation:

[0092] (1)First, use an image acquisition device to segmentally acquire images of the current circumferential surface of the composite pipe to obtain the surface image of the composite pipe; during the weaving process of each layer of the composite pipe, the image acquisition device preferably uses a high-precision industrial camera, which has high resolution, high frame rate and good optical performance, and can clearly capture the detailed features on the surface of the composite pipe. In this embodiment, generally at least three industrial cameras are set, and the industrial cameras are distributed around the axis of the composite pipe, and multiple industrial cameras are fixedly photographed relative to the surface of the composite pipe. Or the industrial camera can be installed on a robotic arm that can move around the axis of the composite pipe, and the movement trajectory of the robotic arm can be controlled by programming to achieve a comprehensive scan of the surface of the composite pipe.

[0093] It should be noted that when installing the industrial camera, in order to ensure the accuracy of image acquisition, the camera needs to be calibrated. Its calibration process generally includes determining the internal parameter data of the camera, such as focal length, principal point coordinates and distortion parameters, and at the same time measuring the radius of the current composite pipe. And it is necessary to establish a cylindrical coordinate system according to the radius and axis position of the composite pipe, and accurately map the pixel coordinates of the image collected by the camera into the cylindrical coordinate system to provide an accurate data basis for subsequent image analysis.

[0094] (2)Secondly, perform image preprocessing on the acquired surface image of the composite pipe; the image preprocessing includes image correction, image stitching and grayscale conversion.

[0095] Specifically, the steps of image correction for the acquired surface image of the composite pipe in this embodiment include:

[0096] Respectively obtain the internal parameter data of the image acquisition device and the radius of the current composite pipe; the internal parameter data at least includes focal length, principal point coordinates and distortion parameters.

[0097] Based on the radius and axis position of the composite pipe, establish a cylindrical coordinate system; it should be noted that since the pipeline is generally long during the manufacturing process of the composite pipe, in this embodiment, the method of segmentally acquiring the surface image of the composite pipe is adopted. For example, for a 2-meter-long composite pipe, the circumferential surface image of the composite pipe can be acquired every 20 cm - 30 cm. When establishing the cylindrical coordinate system, the data acquired at different intervals can be based on the same axis position to establish the cylindrical coordinate system.

[0098] The pixel coordinates of the surface image of the composite pipe collected by the image acquisition device are mapped into the cylindrical coordinate system:

[0099] ;

[0100] where is the angle of the pixel coordinate in the cylindrical coordinate system; is the pixel coordinate Height in the cylindrical coordinate system; The main point coordinates of the composite pipe surface image in the horizontal direction; The main point coordinates of the composite pipe surface image in the vertical direction; The radius of the composite pipe;

[0101] Convert the position of the pixel coordinates in the cylindrical coordinate system to the planar unfolded coordinates :

[0102] .

[0103] Through the above process, the composite pipe surface image collected by the image acquisition device can be converted into a planar unfolded state, which is convenient for subsequent sliding window processing.

[0104] Furthermore, due to the size factor of the composite pipe, a single camera cannot capture the complete circumferential surface at one time. During each composite pipe surface image acquisition process, multiple image acquisition devices are required to take images. In order to obtain the complete composite pipe surface images of different segments, in this embodiment, the collected composite pipe surface images will also be stitched. The specific steps include:

[0105] Use a feature extraction algorithm (such as the SIFT (Scale-Invariant Feature Transform) or SURF (Speeded-Up Robust Features) algorithm) to extract feature points from the planar unfolded composite pipe surface image.

[0106] Based on the feature point matching algorithm, find matching point pairs among the feature points of the composite pipe surface images collected by adjacent image acquisition devices.

[0107] According to the matching point pairs, use the RANSAC (Random Sample Consensus) algorithm to calculate the homography matrix between the composite pipe surface images collected by adjacent image acquisition devices.

[0108] According to the homography matrix between adjacent composite pipe surface images, perform geometric transformation on the composite pipe surface images to align adjacent composite pipe surface images.

[0109] Based on the aligned adjacent composite pipe surface images, find the overlapping area to obtain the image fusion area.

[0110] Based on the image fusion algorithm (such as weighted average fusion or multi-resolution fusion algorithm), stitch and combine the image fusion areas of adjacent composite pipe surface images, and the complete and unfolded composite pipe circumferential surface image of the current segment can be obtained.

[0111] In addition, before performing the sliding window processing on the image, it is also necessary to perform grayscale processing on the image to convert the color image into a grayscale image. Generally, the weighted average method is adopted. According to the contribution degree of different color channels in the RGB color model to the human eye vision, the grayscale value of each pixel point is calculated to obtain the grayscale image.

[0112] (3) Subsequently, the preprocessed composite pipe surface image is slid along the preset directions in a sliding window manner to obtain a number of image segments; the preset directions include a first direction corresponding to the axial direction of the composite pipe and a second direction corresponding to the circumferential direction of the composite pipe. As Figure 2 shown, it is the process of intercepting image segments from the composite pipe surface image using a sliding window, where Figure 2 (a) is the composite pipe surface image, Figure 2 (b) in it is the image segment matrix of the obtained 3×3 matrix. The specific operation process includes:

[0113] Determine the sliding window size and the sliding step according to the diameter of the composite pipe and the image resolution; the selection of the sliding window size should comprehensively consider the size of the composite pipe surface features and the image resolution to ensure that the window can contain sufficient detailed information. The sliding step needs to be adjusted according to the calculation efficiency and the image analysis accuracy.

[0114] Based on the first direction and the second direction, the sliding window slides respectively according to the set sliding step. During the sliding process, a number of image segments are intercepted from the preprocessed composite pipe surface image.

[0115] Finally, a number of image segments are arranged in a matrix distribution according to the acquisition positions of the image segments to obtain an image segment matrix for subsequent similarity calculation and analysis.

[0116] (4) Then, calculate the similarity between adjacent image segments based on the relative entropy algorithm:

[0117] ;

[0118] where is the similarity between adjacent image segment P and image segment Q; is the distribution probability of image segment P; is the distribution probability of image segment Q.

[0119] A general picture is a matrix composed of several pixel points, and each pixel point has a specific color value. The relative entropy algorithm can regard the pixel distribution of a picture as a probability distribution and use relative entropy to measure the difference between two pictures. For example, for two pictures with the same size, the pixel value distributions on each color channel (RGB channel) are statistically analyzed to form probability distributions, and then the relative entropy is calculated to evaluate the degree of their difference. Generally, the larger the relative entropy value, the greater the difference in the pixel distributions of the two pictures and the greater the difference in the picture content. In this embodiment, the above relative entropy algorithm can effectively measure the degree of difference between the probability distributions of two pictures and calculate the similarity value of adjacent pictures. In this embodiment, generally, if the surface fibers of the composite tube are in a uniform state, the relative entropy value of adjacent image segments is low; if the surface fibers of the composite tube are in a non-uniform state, the relative entropy value of adjacent image segments will increase.

[0120] Based on the image segment matrix, calculate the similarity of adjacent image segments in the first direction and the second direction respectively to obtain the first similarity matrix along the first direction D 1 and the second similarity matrix along the second direction D 2:

[0121] ;

[0122] where is representing the image segment in the nth row and mth column; is the image segment along the first direction and the image segment the similarity between; is the image segment along the second direction and the image segment the similarity between.

[0123] Based on the above matrix transformation, the image segment matrix can be converted into similarity value matrices in two directions. In the subsequent outlier judgment stage, the abnormal positions on the surface of the composite tube can be judged and prompted through the first similarity matrix and the second similarity matrix, which is convenient for the operator to accurately locate the surface abnormality in a timely manner.

[0124] Combined with Figure 3 shown, according to Figure 2 the image segment matrix of the 3×3 matrix in can obtain the similarity matrix along the first direction (i.e., the axial direction of the composite tube); as Figure 4 shown, according to Figure 2 the image segment matrix of the 3×3 matrix in can obtain the similarity matrix along the second direction (i.e., the axial direction of the composite tube).

[0125] (6) Finally, judge the uniformity and abnormal positions of the current circumferential surface of the composite tube based on the similarity matrix. The specific steps include:

[0126] First, calculate the mean values of the elements in the first similarity matrix and the second similarity matrix respectively;

[0127] Subsequently, calculate the difference between the element at each position in the first similarity matrix and the corresponding mean value, and calculate the difference between the element at each position in the first similarity matrix and the corresponding mean value;

[0128] Respectively determine whether the absolute value of the calculated difference in the first similarity matrix and the second similarity matrix exceeds a preset threshold:

[0129] When the absolute value of the calculated difference is greater than or equal to the preset threshold, it is determined that the corresponding element in the corresponding similarity matrix is abnormal, indicating poor uniformity of the current image segment. At this time, obtain the corresponding abnormal image segment position according to the positions of the abnormal elements in the corresponding similarity matrix and the positions of the abnormal elements in the second similarity matrix;

[0130] When the absolute value of the calculated difference is less than the preset threshold, it is determined that there is no abnormality, indicating good uniformity of the current image segment.

[0131] Take Figure 3 and Figure 4 in the similarity matrix as an example. For example, when the image segment in the first row and first column of the image segment matrix is abnormal, then Figure 3 the value of T1 in Figure 4 significantly exceeds the mean value of the elements in the first similarity matrix,

[0132] In this embodiment, by converting the probability distribution difference of the image segment into a numerical index, the uniformity of different regions can be quantitatively characterized, and thus it has higher sensitivity to subtle defects, realizing high-quality evaluation; and by constructing a similarity matrix and combining mean deviation analysis, the abnormal region can be located to a single sliding window, realizing centimeter-level precise positioning of the defect position.

[0133] Furthermore, to improve the performance of the composite pipe, the present application improves the braided material during the manufacturing stage of the composite pipe. During the braiding stages of the inner layer, middle layer, and outer layer of the composite pipe, a twisted fiber bundle mixed with high-temperature ceramizable modified silicone rubber fiber impregnated with resin and glass fiber is used, where the high-temperature ceramizable modified silicone rubber fiber is the core material, which can improve the surface performance of the composite pipe. Its specific preparation method includes the following steps:

[0134] (1) Weigh a certain amount of methyl chlorosiloxane rubber, heat it and then immerse it in cyclohexane solvent for pretreatment to obtain pretreated methyl chlorosiloxane rubber;

[0135] (2) Dissolve triethoxysilane in ethanol, add ammonia water to adjust the pH to 4 - 5 to form a hydrolysis solution. Add polydimethylsiloxane to the hydrolysis solution, and disperse the polydimethylsiloxane by ultrasonic treatment. Then add nanoscale aluminum nitride and stir to disperse the aluminum nitride to obtain a silicon nitride precursor solution;

[0136] (3) Mix the silicon nitride precursor solution obtained in step (2) with the pretreated methyl chlorosiloxane rubber obtained in step (1). Heat the mixture to 250 - 300 °C and keep it warm for reaction for 2 - 4 hours to obtain a ceramic precursor material;

[0137] (4) Heat the ceramic precursor material to a molten state, extrude it to form fibers, cool and solidify the fibers, and then perform high-temperature sintering on the fibers;

[0138] (5) Spray a silica dispersion liquid on the surface of the fibers sintered in step (4), and obtain the high-temperature ceramizable modified silicone rubber fibers after drying and solidifying.

[0139] Preferably, the specific pretreatment process in step (1) is: heat the methyl chlorosiloxane rubber to 80 - 100 °C, immerse the heated methyl chlorosiloxane rubber in a cyclohexane solvent, stir for 10 - 15 minutes, and then perform vacuum degassing to obtain the pretreated methyl chlorosiloxane rubber.

[0140] Preferably, the mass ratio of the triethoxysilane to ethanol in step (2) is 1:3 - 5, the mass of the polydimethylsiloxane is 1 - 5% of the hydrolysis solution, and the mass of the nanoscale aluminum nitride is 2 - 5% of the hydrolysis solution; the mass ratio of the silicon nitride precursor solution to the pretreated methyl chlorosiloxane rubber in step (3) is 1:5 - 10; the temperature of the high-temperature sintering in step (4) is 1200 - 1300 °C and is maintained for 2 - 3 hours; the silica dispersion liquid in step (5) is a mixture of silica and ethanol, and the mass-volume ratio of silica to ethanol is 1 g:5 - 10 mL.

[0141] Example:

[0142] (1) Weigh a certain amount of methyl chlorosiloxane rubber, cut it into small pieces, place the methyl chlorosiloxane rubber in a heating tank, heat it to 90 °C to make it soft and enhance its fluidity. Immerse the heated methyl chlorosiloxane rubber in a cyclohexane solvent, stir for 15 minutes to remove the impurities therein, and use a vacuum degassing device to remove air bubbles to ensure that there are no bubbles in the material, and obtain the pretreated methyl chlorosiloxane rubber;

[0143] (2) Add 20 g of triethoxysilane and 80 g of ethanol as a solvent to a beaker, mix them thoroughly, and use an ultrasonic cleaner to treat the solution for 20 minutes to ensure that triethoxysilane is completely dissolved in the solution to form a transparent solution. Add ammonia water to the solution to adjust the pH to 4.5 to promote the hydrolysis and gelation reaction of the silicon nitride precursor to form a hydrolysis solution; add 4 g of polydimethylsiloxane to the hydrolysis solution, treat it with ultrasound for 30 minutes to completely disperse it in the solution, then add 4 g of nano-aluminum nitride, and use a high-speed mixer to mix for 10 minutes to ensure that the powder is completely dispersed and uniform, thereby obtaining a silicon nitride precursor solution;

[0144] (3) 10 g of the silicon nitride precursor solution obtained in step (2) was mixed with 80 g of the pretreated methylchlorosilicone rubber obtained in step (1), and mixed using a high-speed mixer for 10 minutes to ensure that the solution and the silicone rubber were completely mixed. The mixture was heated to 290° C. and kept warm for 3 hours. The silicone rubber matrix began to crosslink, and the silicon nitride precursor reacted with the silicone rubber to obtain a ceramic precursor material.

[0145] (4) The ceramic precursor material is heated to about 230°C to fully melt it and achieve good fluidity. The molten material is extruded using a porous nozzle with a pore size of about 0.5 mm to form continuous fibers. The extruded fibers are cooled and solidified by an air cooling system to ensure rapid fiber molding. The obtained fibers are placed in a high-temperature furnace in an oxygen atmosphere and heated to 1200°C at a rate of 5°C / min, and then heated to 1300°C at a rate of 2°C / min and maintained for 2 hours to convert the silicon nitride precursor into silicon nitride ceramics and react chemically with the silicone rubber matrix.

[0146] (5) Silica and ethanol are mixed in a mass volume ratio of 1 g:8 mL to obtain a silica dispersion, and the silica dispersion is evenly sprayed on the surface of the fiber sintered in step (4) using a spray gun to ensure that the coating is uniform and free of bubbles. The sprayed fiber is placed in an oven at 160° C. and dried for 2 hours to solidify the coating and firmly bond it to the fiber surface, thereby obtaining the high-temperature porcelainizable modified silicone rubber fiber.

[0147] The high-temperature ceramifiable modified silicone rubber fiber and glass fiber prepared through the above embodiments are mixed according to a mass ratio of 1:2. After mixing, the two fiber bundles are wound together through a twisting technique to form a uniform twisted fiber bundle. The twisted fiber bundle is immersed in an epoxy resin impregnating solution to soak the fiber bundle, ensuring that the fiber bundle is completely penetrated by the resin. The fiber bundle after resin impregnation is cured and dried by heating to obtain a resin-impregnated fiber bundle. Subsequently, the obtained resin-impregnated fiber bundle is used for the manufacture of a composite pipe to obtain a finished composite pipe. After performance testing, it is found that the composite pipe has excellent chemical stability, high and low temperature resistance, weather resistance, and insulation properties. At the same time, the skin is less smoky and non-toxic when burning, with the characteristics of low combustion calorific value and slow flame propagation speed. Whether the inside or outside of the composite pipe catches fire, the composite pipe has excellent fire prevention and disaster prevention performance.

[0148] In addition, as Figure 5 shown, the present application also discloses a fiber-reinforced resin composite pipe manufacturing device based on image evaluation, and the device includes:

[0149] An inner layer weaving unit for weaving the inner layer of the composite pipe through a fiber weaving technique;

[0150] An intermediate layer weaving unit for weaving the intermediate layer of the composite pipe on the surface of the inner layer of the composite pipe through a fiber weaving technique;

[0151] An outer layer weaving unit for weaving the outer layer of the composite pipe on the surface of the intermediate layer of the composite pipe through a fiber weaving technique;

[0152] An image evaluation unit for respectively performing image evaluation on the surface of the composite pipe when weaving the inner layer, intermediate layer, and outer layer of the composite pipe:

[0153] Using an image acquisition device to segmentally acquire images of the current circumferential surface of the composite pipe to obtain the composite pipe surface image;

[0154] Performing image preprocessing on the acquired composite pipe surface image; the image preprocessing includes image correction, image stitching, and grayscale conversion;

[0155] Adopting a sliding window method to slide the preprocessed composite pipe surface image along a preset direction respectively to obtain a plurality of image segments; the preset direction includes a first direction corresponding to the axial direction of the composite pipe and a second direction corresponding to the circumferential direction of the composite pipe;

[0156] Calculating the similarity of adjacent image segments based on the relative entropy algorithm:

[0157] ;

[0158] where is the similarity of adjacent image segments P and image segment Q; is the distribution probability of the image segment P; is the distribution probability of the image segment Q;

[0159] Obtain the similarity matrix of the composite pipe surface image according to the similarity calculation result;

[0160] Based on the similarity matrix, judge the uniformity and abnormal positions of the current circumferential surface of the composite pipe.

[0161] The device provided by the embodiment of the present application can implement Figure 1 each process implemented by the method embodiment. To avoid repetition, it will not be elaborated here.

[0162] As Figure 6 shown, the embodiment of the present application also provides an electronic device, including a processor and a memory, a program or instruction stored on the memory and executable on the processor. When the program or instruction is executed by the processor, it implements each process of the method embodiment as shown in Figure 1 and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0163] The embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by the processor, it implements each process of the above-mentioned Figure 1 method embodiment and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0164] The embodiment of the present application also provides a computer program product, including a computer instruction. When the computer instruction is executed by the processor, it implements each process of the above-mentioned Figure 1 method embodiment and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0165] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the present application. Therefore, the appearances of "in one embodiment" or "in an embodiment" throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the order numbers of the above processes do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiment of the present application. The serial numbers of the embodiments of the present application above are only for description and do not represent the advantages and disadvantages of the embodiments.

[0166] It should be noted that in this article, 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 not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including such element.

[0167] In several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined, or can be integrated into another device, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the displayed or discussed components can be through some interfaces. The indirect coupling or communication connection of devices or units can be electrical, mechanical, or other forms.

[0168] The units described above as separate components may or may not be physically separated. The components displayed as units may or may not be physical units; they can be located in one place or distributed to multiple network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0169] In addition, each functional unit in the embodiments of this application can be all integrated in a processing unit, or each unit can be separately used as a unit, or two or more units can be integrated in one unit; the above integrated units can be implemented in the form of hardware, or in the form of a combination of hardware and software functional units.

[0170] Those of ordinary skill in the art can understand that all or part of the steps to implement the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiments; and the foregoing storage media include: various media that can store program codes such as removable storage devices, read-only memory (ROM), magnetic disks, or optical discs.

[0171] Alternatively, if the above integrated units of the present application are implemented in the form of software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a device (which can be a terminal or a platform, etc.) to execute all or part of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media that can store program codes such as removable storage devices, ROMs, magnetic disks, or optical discs.

[0172] The above are only the preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present application, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A method for manufacturing a fiber-reinforced resin composite pipe based on image evaluation, characterized in that: The method comprises the following steps: The inner layer of the composite tube is obtained by weaving through fiber weaving technology; the inner layer is woven from twisted fiber bundles of high-temperature vitrified modified silicone rubber fibers impregnated with resin and mixed with glass fibers; The middle layer of the composite pipe is obtained by weaving the inner surface of the composite pipe with a fiber weaving technology; the middle layer includes at least two layers, and the middle layer is woven with a twisted fiber bundle of a mixture of high-temperature porcelain-modified silicone rubber fiber impregnated with resin and glass fiber; The outer layer of the composite pipe is obtained by weaving the surface of the middle layer of the composite pipe using a fiber weaving technology; the outer layer includes a first outer layer and a second outer layer located on the surface of the first outer layer, the first outer layer is woven by multiple strands of glass fiber impregnated with resin, and the second outer layer is woven by twisted fiber bundles of high-temperature porcelain-modified silicone rubber fibers impregnated with resin and mixed with glass fibers; When weaving the inner layer, middle layer and outer layer of the composite tube, image evaluation is performed on the surface of the composite tube respectively: Using an image acquisition device to acquire images of the current circumferential surface of the composite pipe in sections to obtain a surface image of the composite pipe; Performing image preprocessing on the collected composite tube surface image; the image preprocessing includes image correction, image stitching and grayscale conversion; The preprocessed composite tube surface image is slid along preset directions by a sliding window method to obtain a plurality of image segments; the preset directions include a first direction corresponding to the axial direction of the composite tube and a second direction corresponding to the circumferential direction of the composite tube; Calculate the similarity of adjacent image segments based on the relative entropy algorithm: ； in is the similarity between adjacent image segments P and Q; is the distribution probability of the image segment P; is the distribution probability of image segment Q; Obtaining a similarity matrix of the composite tube surface image according to the similarity calculation result; The uniformity of the current circumferential surface of the composite pipe and the abnormal position are determined based on the similarity matrix.

2. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 1, characterized in that: The step of performing image preprocessing on the collected composite tube surface image comprises: Acquire internal parameter data of the image acquisition device and the radius of the current composite tube respectively; the internal parameter data at least includes focal length, principal point coordinates and distortion parameters; A cylindrical coordinate system is established based on the radius and axis position of the composite tube; The pixel coordinates of the composite tube surface images collected by different image acquisition devices are Mapping into cylindrical coordinates: ； in is the pixel coordinate Angle in cylindrical coordinates; is the pixel coordinate Height in cylindrical coordinates; is the principal point coordinate of the composite tube surface image in the horizontal direction; is the principal point coordinate of the composite tube surface image in the vertical direction; is the radius of the composite tube; Convert pixel coordinates in cylindrical coordinate system into planar unfolded coordinates : 。 3. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 2, characterized in that: The step of performing image preprocessing on the collected composite tube surface image comprises: The feature extraction algorithm is used to extract feature points from the surface image of the composite tube after plane expansion; Finding matching point pairs among the feature points of the composite tube surface images acquired by adjacent image acquisition devices based on feature point matching; According to the matching point pairs, the homography matrix between the composite tube surface images acquired by adjacent image acquisition devices is calculated using the RANSAC algorithm; According to the homography matrix between adjacent composite tube surface images, geometric transformation is performed on the composite tube surface images to align the adjacent composite tube surface images; Find the overlapping area based on the aligned adjacent composite tube surface images to obtain the image fusion area; Based on the image fusion algorithm, the image fusion areas of adjacent composite pipe surface images are spliced ​​and combined to obtain a complete and unfolded composite pipe circumferential surface image.

4. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 1, characterized in that: The step of sliding the pre-processed composite pipe surface image along the preset direction in a sliding window manner comprises: Determine the sliding window size and sliding step length according to the composite tube diameter and image resolution; Based on the first direction and the second direction, the sliding window slides according to the set sliding step length to obtain a plurality of image segments; According to the acquisition positions of the image segments, a plurality of image segments are arranged and distributed in a matrix to obtain an image segment matrix.

5. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 1, characterized in that: The step of obtaining a similarity matrix of the composite tube surface image according to the similarity calculation result comprises: Based on the image segment matrix, similarities are calculated for adjacent image segments according to a first direction and a second direction respectively to obtain a similarity matrix along the first direction. D 1 and the similarity matrix along the second direction D 2: ； Among them is Represents the image fragment at row n and column m; is the image segment along the first direction and image fragments The similarity between is the image segment along the second direction and image fragments The similarity between .

6. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 1, characterized in that: The step of judging the uniformity of the current circumferential surface of the composite pipe and the abnormal position based on the similarity matrix comprises: Calculate the means of the elements in the first similarity matrix and the second similarity matrix respectively; Calculating the difference between the element at each position in the first similarity matrix and the corresponding mean and calculating the difference between the element at each position in the first similarity matrix and the corresponding mean; Determine whether the absolute values ​​of the calculated differences in the first similarity matrix and the second similarity matrix exceed a preset threshold: When the absolute value of the calculated difference is greater than or equal to a preset threshold, the corresponding element in the corresponding similarity matrix is ​​judged to be abnormal, and the corresponding abnormal image segment position is obtained according to the position of the abnormal element in the corresponding similarity matrix; When the absolute value of the calculated difference is less than the preset threshold, it is determined that there is no abnormality.

7. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 1, characterized in that: The preparation method of the high temperature porcelainizable modified silicone rubber fiber comprises the following steps: (1) Weighing a certain amount of methyl chlorosilicone rubber, heating it and immersing it in a cyclohexane solvent for pretreatment to obtain pretreated methyl chlorosilicone rubber; (2) dissolving triethoxysilane in ethanol, adding ammonia water to adjust the pH to 4-5 to form a hydrolysis solution, adding polydimethylsiloxane to the hydrolysis solution, ultrasonically treating to disperse the polydimethylsiloxane, then adding nano-sized aluminum nitride, stirring to disperse the aluminum nitride, and obtaining a silicon nitride precursor solution; (3) mixing the silicon nitride precursor solution obtained in step (2) with the pretreated methylchlorosilicone rubber obtained in step (1), heating the mixture to 250° C.-300° C., and keeping the mixture to react for 2 hours-4 hours to obtain a ceramic precursor material; (4) heating the ceramic precursor material to a molten state, extruding it to form fibers, cooling and solidifying the fibers, and then sintering the fibers at a high temperature; (5) Spraying a silicon dioxide dispersion onto the surface of the fiber after sintering in step (4), and drying and curing to obtain the high temperature porcelainizable modified silicone rubber fiber.

8. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 7, characterized in that: The pretreatment process of step (1) is specifically as follows: heating the methyl chlorosilicone rubber to 80°C-100°C, immersing the heated methyl chlorosilicone rubber in a cyclohexane solvent, stirring for 10 minutes-15 minutes, and then vacuum degassing to obtain the pretreated methyl chlorosilicone rubber.

9. The method for manufacturing a fiber-reinforced resin composite pipe according to claim 7, characterized in that: In step (2), the mass ratio of triethoxysilane to ethanol is 1:3-1:5, the mass of polydimethylsiloxane is 1%-5% of the hydrolysis solution, and the mass of nano-aluminum nitride is 2%-5% of the hydrolysis solution; in step (3), the mass ratio of silicon nitride precursor solution to pretreated methylchlorosilicone rubber is 1:5-1:10; in step (4), the temperature of high-temperature sintering is 1200°C-1300°C, and is maintained for 2 hours-3 hours; in step (5), the silicon dioxide dispersion is a mixture of silicon dioxide and ethanol, and the mass volume ratio of silicon dioxide to ethanol is 1g:5mL-1g:10mL.

10. A fiber-reinforced resin composite pipe manufacturing device based on image evaluation, characterized in that: The device comprises: The inner layer braiding unit is used to braid the inner layer of the composite tube by fiber braiding technology; the inner layer is braided with a twisted fiber bundle of a mixture of high temperature vitrified modified silicone rubber fiber impregnated with resin and glass fiber; The intermediate layer braiding unit is used to braid the inner layer surface of the composite pipe by using fiber braiding technology to obtain the intermediate layer of the composite pipe; the intermediate layer includes at least two layers, and the intermediate layer is braided by twisted fiber bundles mixed with high-temperature porcelain-modified silicone rubber fibers impregnated with resin and glass fibers; The outer layer braiding unit is used to braid the outer layer of the composite pipe by using fiber braiding technology on the surface of the middle layer of the composite pipe; the outer layer includes a first outer layer and a second outer layer located on the surface of the first outer layer, the first outer layer is braided by multiple strands of glass fiber impregnated with resin, and the second outer layer is braided by twisted fiber bundles mixed with high-temperature porcelain-modified silicone rubber fibers impregnated with resin and glass fibers; Image evaluation unit for image evaluation of the composite pipe surface during braiding of the inner layer, the middle layer and the outer layer: Using an image acquisition device to acquire images of the current circumferential surface of the composite pipe in sections to obtain a surface image of the composite pipe; Performing image preprocessing on the collected composite tube surface image; the image preprocessing includes image correction, image stitching and grayscale conversion; The preprocessed composite tube surface image is slid along preset directions by a sliding window method to obtain a plurality of image segments; the preset directions include a first direction corresponding to the axial direction of the composite tube and a second direction corresponding to the circumferential direction of the composite tube; Calculate the similarity of adjacent image segments based on the relative entropy algorithm: ； in is the similarity between adjacent image segments P and Q; is the distribution probability of the image segment P; is the distribution probability of image segment Q; Obtaining a similarity matrix of the composite tube surface image according to the similarity calculation result; The uniformity of the current circumferential surface of the composite pipe and the abnormal position are determined based on the similarity matrix.

Images