Straight groove type gum dipping system suitable for pultrusion process

Abstract

The invention provides a straight groove type gum dipping system suitable for a pultrusion process, comprising: a gum injection module for performing gum dipping operation on fibers; the detection module is used for monitoring and controlling the impregnation quality of the glue injection module by using a camera device on the outer side of the glue injection module, controlling the working state of the glue injection module by using a floating ball sensing device on the inner side of the glue injection module, and evaluating the impregnation quality through a built-in visual recognition algorithm; wherein the camera device monitors the liquid level of the glue solution in real time and feeds back the change rate of the liquid level, and working parameters of the camera device are adjusted according to the change rate of the liquid level; and the interaction module is used for feeding back the evaluation result of the detection module to the client, and a worker adjusts various parameters in the gum dipping operation according to the evaluation result. The automatic detection device has the beneficial effects that through the design that the camera device is combined with the floating ball to sense the liquid level of the glue solution, automatic detection of the production quality is completed, the working efficiency is improved, and the labor cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of quality monitoring, and in particular relates to a straight trough type glue dipping system suitable for a pultrusion process. Background Art

[0002] Pultrusion is a process for producing composite material profiles by fully impregnating continuous fibers or fabrics with resin under the traction of a traction device and then heating the mold to solidify the resin. This molding method has the advantages of excellent longitudinal mechanical properties of the product, low manufacturing cost, high degree of automation, and stable product performance.

[0003] The main steps of pultrusion process include yarn guiding, dipping, preforming, curing, pulling and cutting. At present, the pultrusion process generally adopts an open roller dipping system, which has problems such as uneven fiber tension, poor fiber impregnation effect, and glue contamination, resulting in reduced product performance and poor straightness, affecting the application of pultruded profiles.

[0004] In the prior art, problems such as fiber fuzzing, poor impregnation, uneven fiber tension, and glue pollution and waste are solved by closed low-pressure glue injection and designed reflux grooves. However, unlike polyurethane, epoxy resin glue has a higher viscosity, and the closed glue dipping method has the problem of poor dipping. However, the closed glue tank cannot detect the problem immediately, thus causing product defects. In addition, the use of manual methods to observe product problems consumes too much manpower. Summary of the invention

[0005] In view of this, the present invention aims to provide a straight trough dipping system suitable for pultrusion process, in order to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows: A straight trough type dipping system suitable for pultrusion process, comprising: Glue injection module, used for dipping fibers in glue; The detection module uses a camera device on the outside of the glue injection module to monitor and control the glue dipping quality of the glue injection module, uses a float sensing device on the inside of the glue injection module to control the working state of the glue injection module, and evaluates the glue dipping quality through a built-in visual recognition algorithm; wherein the camera device monitors the glue liquid level in real time and feeds back the liquid level change rate, and adjusts the working parameters of the camera device according to the liquid level change rate; The interactive module feeds back the evaluation results of the detection module to the client, and the staff adjusts the various parameters in the dipping operation based on the evaluation results.

[0007] Furthermore, the glue injection module includes: A straight-groove glue injection tank, one end of which receives the fiber product, and the other end of which is connected to a heatable cold mold through a sealing partition. The sealing cover of the straight-groove glue injection tank is a transparent structural member, and the sealing cover is connected to the straight-groove glue injection tank through a hinge; Heatable cold die for heating the impregnated fibers using a heating plate.

[0008] Furthermore, the working process of the detection module includes: The camera device captures images during the dipping operation in real time; Performing preprocessing operations on the captured images, the preprocessing operations including median filtering denoising, adjusting brightness contrast, and color space conversion; The key features in the preprocessed image are extracted, and the unqualified areas are divided in the image according to the key features. The unqualified areas are compared with the preset quality standard map, and the evaluation results of the dipping quality are given according to the comparison.

[0009] Furthermore, the key features extracted from the preprocessed image include: Extract the color characteristics of the colloid part, analyze the uniformity of the colloid distribution, and obtain the uniformity of the dipping; Extract the structural characteristics of the fiber part, analyze whether the fiber is arranged neatly, whether there is dislocation and stacking, and obtain the fiber arrangement neatness; The part of the image with significantly different brightness from the surrounding area is extracted, and the shape characteristics of the part are analyzed to obtain the bubble influence.

[0010] Further, the analysis process of the dipping uniformity is as follows: Convert the image from RGB color space to HSV color space; Quantize the color value of each pixel and divide the color space into multiple discrete parts, each of which identifies a color range; Perform color analysis on each part, calculate the frequency of occurrence of each color in each part, and analyze the uniformity of dipping based on the frequency of occurrence and the distribution of the color in each part.

[0011] Furthermore, the analysis process of the fiber arrangement regularity is as follows: Quantify the grayscale level of the image and compress it to a smaller range; Preset a direction and distance to define the relative position of pixel pairs; For each pair of pixels, if they are adjacent in the specified distance and direction, the value at the corresponding position is increased by 1, and the frequencies of all pixel pairs are stored in a matrix; The texture features are extracted from the matrix to obtain the fiber alignment.

[0012] Furthermore, the analysis process of the bubble influence is as follows: The image is binarized and divided into highlight area and low-brightness area according to the brightness difference. The number of pixels in the low-brightness area of ​​the current image is calculated to obtain the area of ​​the bubble part, and the bubble influence is calculated according to the area size.

[0013] Furthermore, the influence of the bubble is equal to the ratio of the area of ​​the bubble part to the total area of ​​the non-background part in the image.

[0014] Furthermore, the process of adjusting the working parameters of the camera device according to the liquid level change rate is specifically as follows: When the floating change rate of the glue liquid surface increases, the shutter time of the camera device is shortened and the aperture is reduced; when the floating change rate of the glue liquid surface decreases, the shutter time is increased and the aperture is expanded.

[0015] Furthermore, a brightness threshold of the image is preset; Under the current shutter time, when the aperture is adjusted to the maximum value and the brightness of the image is still lower than the threshold, the sensitivity of the camera device is increased; otherwise, the sensitivity remains unchanged.

[0016] Compared with the prior art, the straight trough type dipping system suitable for pultrusion process described in the present invention has the following beneficial effects: The use of a transparent observable closing cover and a heatable cold mold facilitates the monitoring of production quality and improves production speed. At the same time, the camera device combined with the design of a float sensing the glue liquid level completes the automated detection of production quality, improves work efficiency and reduces labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 The structure and function diagram of the straight trough type dipping system suitable for pultrusion process described in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0022] A straight trough type dipping system suitable for pultrusion process, comprising: Glue injection module, used for dipping fibers in glue; The detection module uses a camera device on the outside of the glue injection module to monitor and control the glue dipping quality of the glue injection module, uses a float sensing device on the inside of the glue injection module to control the working state of the glue injection module (glue injection time, glue injection amount, glue injection speed), and evaluates the glue dipping quality through a built-in visual recognition algorithm; wherein the camera device monitors the glue liquid level in real time and feeds back the liquid level change rate, and adjusts the working parameters of the camera device according to the liquid level change rate; The interactive module feeds back the evaluation results of the detection module to the client, and the staff adjusts the various parameters in the dipping operation based on the evaluation results.

[0023] The glue injection module comprises: A straight-groove glue injection tank, one end of which receives the fiber product, and the other end of which is connected to a heatable cold mold through a sealing partition. The sealing cover of the straight-groove glue injection tank is a transparent structural member, and the sealing cover is connected to the straight-groove glue injection tank through a hinge; Heatable cold die for heating the impregnated fibers using a heating plate.

[0024] The working process of the detection module includes: The camera device captures images during the dipping operation in real time; Performing preprocessing operations on the captured images, the preprocessing operations including median filtering denoising, adjusting brightness contrast, and color space conversion; The key features in the preprocessed image are extracted, and the unqualified areas are divided in the image according to the key features. The unqualified areas are compared with the preset quality standard map, and the evaluation results of the dipping quality are given according to the comparison.

[0025] The key features of the extracted pre-processed image include: Extract the color characteristics of the colloid part, analyze the uniformity of the colloid distribution, and obtain the uniformity of the dipping; Extract the structural characteristics of the fiber part, analyze whether the fiber is arranged neatly, whether there is dislocation and stacking, and obtain the fiber arrangement neatness; The parts with different brightness in the image are extracted, and the analysis and judgment are made as to whether the parts are the bubble areas. The shape features of the bubble areas are extracted to obtain the bubble influence degree.

[0026] The analysis process of the dipping uniformity is as follows: Convert the image from RGB color space to HSV color space; Quantize the color value of each pixel and divide the color space into multiple discrete parts, each of which identifies a color range; Perform color analysis on each part, calculate the frequency of occurrence of each color in each part, and analyze the uniformity of dipping based on the frequency of occurrence and the distribution of the color in each part.

[0027] The formula for calculating the frequency of occurrence of each color in each section is: ; Where I is the set of all pixels in the image, representing the input image; p(x,y) is the pixel at the (x,y) coordinate in the image. c(p(x,y)) is the color value of pixel p(x,y), which is specifically represented as hue, saturation, and brightness in the HSV color space; H c (i) is the value of the i-th bin in the color histogram, indicating the frequency of the pixel with color value i in the image; δ(x) is the indicator function, when x is true, the function value is 1, otherwise it is 0; N is the number of bins in the color channel.

[0028] In order to make the histogram unaffected by the image size, the normalized color histogram is: ,in, is the normalized color histogram, which indicates the relative frequency of color value i in the image. It is the sum of all bins of the histogram, that is, the total number of all color pixels in the image.

[0029] The analysis process of the fiber arrangement uniformity is as follows: Quantify the grayscale level of the image and compress it to a smaller range; Preset a direction and distance to define the relative position of pixel pairs; For each pair of pixels, if they are adjacent in the specified distance and direction, the value at the corresponding position is increased by 1, and the frequencies of all pixel pairs are stored in a matrix; The texture features are extracted from the matrix to obtain the fiber alignment.

[0030] The definition formula of the matrix is: P(i,j)=∑ x,y δ(I(x,y)=i,I(x+d,y+d)=j); Among them, i,j are grayscale levels, indicating the grayscale values ​​of two pixels in the image; P(i,j) is an element in the co-occurrence matrix, indicating the frequency of occurrence of pixel pairs with grayscale values ​​i and j at a certain distance and direction; δ is an indicator function, which takes a value of 1 when the condition is met, otherwise it is 0; I(x,y) is the grayscale value of the pixel (x,y) in the image; d is the specified distance, usually 1; θ is the direction, common angles include 0° (horizontal), 45°, 90° (vertical), and 135° (diagonal).

[0031] A variety of texture features can be extracted from the matrix, including: A= , Where i and j are the gray values ​​in the co-occurrence matrix; P(i,j) is the co-occurrence frequency of the corresponding gray values ​​i and j; The larger the value of A is, the greater the grayscale difference of the image is. If the value of A at a certain point in the image is too small, it means that the fibers are aggregated and stacked there, which is considered unqualified.

[0032] B= ,in; μx and μy are the average grayscale values ​​of i and j respectively: , ; σx and σy are the standard deviations of i and j respectively: , ; The higher the B value, the more regular the grayscale changes in the image. If the B value at a certain point in the image is too low, it means that the fibers are arranged in a disorderly manner and are considered unqualified.

[0033] C= The larger the C value, the smoother the texture of the image and the smaller the grayscale change. If the C value at a certain point in the image is too small, it means that the fiber is bent and curled at this point, which is considered unqualified.

[0034] In order to improve the detection efficiency and enable the staff to obtain more intuitive analysis results, the above three parameters A, B, and C are used for further calculation to obtain the value of fiber arrangement uniformity. The specific process is as follows: ; ; Among them, α1, α2, α3 are the weights of each characteristic first-order derivative, satisfying α1+α2+α3=1; β3 is the weight of the uniformity second-order derivative, which is only when the liquid level change rate exceeds L threshold When it works; L threshold Liquid level change rate The threshold value.

[0035] The analysis process of the bubble influence is as follows: The image is binarized and divided into highlight area and low-brightness area according to the brightness difference. The number of pixels in the low-brightness area of ​​the current image is calculated to obtain the area of ​​the bubble part, and the bubble influence is calculated according to the area size.

[0036] The formula for calculating the number of pixels in the low-light area is: ; Among them, δ(I(x,y)−1) is the indicator function. When the value of pixel I(x,y) is 1 (i.e., foreground pixel), the return value is 1, otherwise it is 0; (x,y) is a pixel position in the image, I(x,y) represents the grayscale value or binary value (0 or 1) of the pixel; ∑i,j represents the sum of all image pixels to calculate the total number of pixels in the foreground area.

[0037] The influence of the bubble is equal to the ratio of the area of ​​the bubble part to the total area of ​​the non-background part in the image.

[0038] The larger the value of the bubble impact, the more serious the impact of the bubbles on the resin layer. Usually, when the impact exceeds a certain threshold (such as 10% or 20%), the system will determine that the image is of unqualified quality and requires further adjustment or repair.

[0039] The process of adjusting the working parameters of the camera device according to the liquid level change rate is specifically as follows: When the floating change rate of the glue liquid surface increases, the shutter time of the camera device is shortened and the aperture is reduced; when the floating change rate of the glue liquid surface decreases, the shutter time is increased and the aperture is expanded.

[0040] Preset the brightness threshold of the image; Under the current shutter time, when the aperture is adjusted to the maximum value and the brightness of the image is still lower than the threshold, the sensitivity of the camera device is increased; otherwise, the sensitivity remains unchanged.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A straight trough dipping system suitable for pultrusion process, characterized in that: include: Glue injection module, used for dipping fibers in glue; The detection module uses a camera device on the outside of the glue injection module to monitor and control the glue dipping quality of the glue injection module, uses a float sensing device on the inside of the glue injection module to control the working state of the glue injection module, and evaluates the glue dipping quality through a built-in visual recognition algorithm; wherein the camera device monitors the glue liquid level in real time and feeds back the liquid level change rate, and adjusts the working parameters of the camera device according to the liquid level change rate; The interactive module feeds back the evaluation results of the detection module to the client, and the staff adjusts the various parameters in the dipping operation based on the evaluation results.

2. A straight trough type dipping system suitable for pultrusion process according to claim 1, characterized in that: The glue injection module comprises: A straight-groove glue injection tank, one end of which receives the fiber product, and the other end of which is connected to a heatable cold mold through a sealing partition. The sealing cover of the straight-groove glue injection tank is a transparent structural member, and the sealing cover is connected to the straight-groove glue injection tank through a hinge; Heatable cold die for heating the impregnated fibers using a heating plate.

3. A straight trough type dipping system suitable for pultrusion process according to claim 1, characterized in that: The working process of the detection module includes: The camera device captures images during the dipping operation in real time; Performing preprocessing operations on the captured images, the preprocessing operations including median filtering denoising, adjusting brightness contrast, and color space conversion; The key features in the preprocessed image are extracted, and the unqualified areas are divided in the image according to the key features. The unqualified areas are compared with the preset quality standard map, and the evaluation results of the dipping quality are given according to the comparison.

4. A straight trough type dipping system suitable for pultrusion process according to claim 3, characterized in that: The key features of the extracted pre-processed image include: Extract the color characteristics of the colloid part, analyze the uniformity of the colloid distribution, and obtain the uniformity of the dipping; Extract the structural characteristics of the fiber part, analyze whether the fiber is arranged neatly, whether there is dislocation and stacking, and obtain the fiber arrangement neatness; The part of the image with significantly different brightness from the surrounding area is extracted, and the shape characteristics of the part are analyzed to obtain the bubble influence.

5. A straight trough type dipping system suitable for pultrusion process according to claim 4, characterized in that: The analysis process of the dipping uniformity is as follows: Convert the image from RGB color space to HSV color space; Quantize the color value of each pixel and divide the color space into multiple discrete parts, each of which identifies a color range; Perform color analysis on each part, calculate the frequency of occurrence of each color in each part, and analyze the uniformity of dipping based on the frequency of occurrence and the distribution of the color in each part.

6. A straight trough type dipping system suitable for pultrusion process according to claim 4, characterized in that: The analysis process of the fiber arrangement uniformity is as follows: Quantify the grayscale level of the image and compress it to a smaller range; Preset a direction and distance to define the relative position of pixel pairs; For each pair of pixels, if they are adjacent in the specified distance and direction, the value at the corresponding position is increased by 1, and the frequencies of all pixel pairs are stored in a matrix; The texture features are extracted from the matrix to obtain the fiber alignment.

7. A straight trough type dipping system suitable for pultrusion process according to claim 4, characterized in that: The analysis process of the bubble influence is as follows: The image is binarized and divided into highlight area and low-brightness area according to the brightness difference. The number of pixels in the low-brightness area of ​​the current image is calculated to obtain the area of ​​the bubble part, and the bubble influence is calculated according to the area size.

8. A straight trough type dipping system suitable for pultrusion process according to claim 7, characterized in that: The influence of the bubble is equal to the ratio of the area of ​​the bubble part to the total area of ​​the non-background part in the image.

9. The straight trough type dipping system suitable for pultrusion process according to claim 1, characterized in that: The process of adjusting the working parameters of the camera device according to the liquid level change rate is specifically as follows: When the floating change rate of the glue liquid surface increases, the shutter time of the camera device is shortened and the aperture is reduced; when the floating change rate of the glue liquid surface decreases, the shutter time is increased and the aperture is expanded.

10. A straight trough type dipping system suitable for pultrusion process according to claim 9, characterized in that: Preset the brightness threshold of the image; Under the current shutter time, when the aperture is adjusted to the maximum value and the brightness of the image is still lower than the threshold, the sensitivity of the camera device is increased; otherwise, the sensitivity remains unchanged.

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