Carbon fiber splitting detection method, device, equipment and medium

Abstract

The present invention relates to the technical field of carbon fiber production, and in particular to a method, device, equipment and medium for detecting split wires of carbon fiber. The method comprises: obtaining a carbon fiber yarn image, and converting the yarn image into a grayscale image; filtering out pixel points in the grayscale image by a grayscale value threshold, and extracting a number of regions by segmenting a connected domain; obtaining the minimum circumscribed rectangle of each region, and calculating the complement of the region and the minimum circumscribed rectangle; calculating the inflection points of the pixel points in the complement, and determining the number of inflection points greater than a distance threshold; if the number exceeds a set number, it is determined that there is a split wire defect in the region. In the present invention, the inflection points of the pixel points are calculated in the complement region, and if the number of inflection points in a certain region exceeds a preset threshold, it is determined that there is a split wire defect in the region, and the split wire defect in the carbon fiber yarn is automatically detected by image processing technology, which can effectively improve the detection accuracy, reduce the omission of manual detection, and thus ensure the quality of carbon fiber products.

Description

Technical Field

[0001] The invention relates to the technical field of carbon fiber production, and in particular to a carbon fiber splitting detection method, device, equipment and medium. Background Art

[0002] Carbon fiber has a series of excellent properties such as high specific strength, high specific modulus, fatigue resistance, creep resistance, corrosion resistance and small thermal expansion coefficient. Therefore, it is widely used as the reinforcement of carbon fiber reinforced resin-based composites (CFRP) in cutting-edge defense technologies such as aerospace and aviation. It is also a new material for the upgrading of civilian industries.

[0003] In the process of carbon fiber production, due to the excessively fast production line speed, splitting defects will occur, affecting the normal production of carbon fiber and the quality of yarn. However, due to the product process, it is impossible to achieve 100% inspection manually, and errors are prone to occur.

[0004] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0005] The present invention provides a carbon fiber splitting detection method, device, equipment and medium, thereby effectively solving the problems in the background technology.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a carbon fiber splitting detection method, comprising the following steps:

[0007] Acquire a carbon fiber yarn image, and convert the yarn image into a grayscale image;

[0008] Filtering out pixels in the grayscale image by using a grayscale value threshold, and extracting a number of regions by segmenting connected domains;

[0009] Obtaining the minimum bounding rectangle of each of the regions, and calculating the complement of the region and the minimum bounding rectangle;

[0010] Calculating the inflection points of the pixel points in the complement, and determining the number of inflection points greater than a distance threshold;

[0011] If the number exceeds the set number, it is determined that the region has a split wire defect.

[0012] Furthermore, the calculating of the inflection point of the pixel point in the complement includes the following steps:

[0013] Calculate a straight line connecting two pixel points at both ends of the complement set, calculate the distance between all points in the complement set and the straight line, and find the maximum distance value;

[0014] Determine whether the maximum distance value is less than the distance threshold;

[0015] If it is less than, discard all the points between the two ends of the straight line;

[0016] If it is greater than, the pixel point corresponding to the maximum distance value is retained, and the pixel point is used as the inflection point to divide the complement into two parts, and the judgment steps of the maximum distance value and the distance threshold are repeated for the two parts.

[0017] Furthermore, the step of determining whether to repeatedly use the maximum distance value and the distance threshold for the two parts includes:

[0018] Taking the inflection point as a boundary, dividing the complement set into two parts;

[0019] Connect the endpoints of the two parts to form a straight line, and determine the distance between all points in the two parts and the straight line, and find the maximum distance value;

[0020] Determine whether the maximum distance value is less than the distance threshold;

[0021] If it is less than, discard all the points between the two ends of the straight line;

[0022] If it is greater than, the pixel point corresponding to the maximum distance value is retained, and this point is used as the inflection point to continue segmenting the part until it can no longer be segmented.

[0023] Furthermore, the two pixel points at both ends of the complementary set are respectively: two pixel points with the smallest and largest coordinate values ​​on the coordinate axis corresponding to the yarn width direction in the yarn image.

[0024] Furthermore, the gray value threshold range is [1, 125].

[0025] The present invention also includes a carbon fiber splitting detection device, using the above method, the detection device includes:

[0026] An image acquisition unit, used for acquiring a carbon fiber yarn image and converting the yarn image into a grayscale image;

[0027] A region segmentation unit, used to filter out pixels in the grayscale image by grayscale value threshold, and extract a number of regions by segmenting connected domains;

[0028] A complement unit, used for obtaining the minimum bounding rectangle of each of the regions, and calculating the complement of the region and the minimum bounding rectangle;

[0029] An inflection point calculation unit, used to calculate the inflection points of the pixel points in the complement set, and determine the number of inflection points greater than a distance threshold;

[0030] The judging unit is used to judge whether a wire splitting defect exists in the region if the number of inflection points exceeds a set number.

[0031] The present invention also includes a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described above is implemented.

[0032] The present invention also includes a storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described above is implemented.

[0033] The beneficial effects of the present invention are as follows: the present invention converts the acquired yarn image into a grayscale image for subsequent image processing, sets a threshold value of the grayscale value, screens out valid pixel points in the grayscale image according to the threshold value, performs connected domain segmentation on the screened pixel points, extracts a number of independent areas in the image, calculates the complementary area between each area and its minimum circumscribed rectangle, that is, the pixel points in the minimum circumscribed rectangle that do not belong to the area, calculates the inflection points of the pixel points in the complementary area, identifies the turning points of the curve or edge, and if the number of inflection points in a certain area exceeds a preset threshold value, it is determined that the area has a split wire defect, and automatically detects the split wire defect in the carbon fiber yarn through image processing technology, which can effectively improve the detection accuracy and reduce the omissions of manual detection, thereby ensuring the quality of carbon fiber products. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 is a flow chart of the method of the present invention;

[0036] Figure 2 is a schematic diagram of a grayscale image;

[0037] Figure 3 Schematic diagram of several extracted regions;

[0038] Figure 4 Schematic diagram of detecting split wire defects;

[0039] Figure 5 It is a structural schematic diagram of the device of the present invention;

[0040] Figure 6 It is a structural schematic diagram of the computer device of the present invention. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0042] like Figure 1 A method for detecting split carbon fiber wires includes the following steps:

[0043] Obtain a carbon fiber yarn image and convert the yarn image into a grayscale image. The grayscale image is as follows: Figure 2 As shown;

[0044] The pixel points in the grayscale image are screened out by grayscale value threshold, and several regions are extracted by segmenting the connected domain. Figure 3 As shown;

[0045] Find the minimum enclosing rectangle of each region and calculate the complement of the region and the minimum enclosing rectangle;

[0046] Calculate the inflection points of the pixels in the complement set and determine the number of inflection points greater than the distance threshold;

[0047] If the number exceeds the set number, the area is judged to have a split wire defect, the inflection point is extracted and judged as a split wire defect. Figure 4 shown.

[0048] The acquired yarn image is converted into a grayscale image for subsequent image processing. A threshold of the grayscale value is set, and valid pixels in the grayscale image are screened out according to the threshold. The screened pixels are segmented into connected domains, and several independent areas in the image are extracted. The complementary area between each area and its minimum circumscribed rectangle is calculated, that is, the pixels in the minimum circumscribed rectangle that do not belong to the area. In the complementary area, the inflection points of the pixels are calculated, and the turning points of the curves or edges are identified. If the number of inflection points in a certain area exceeds the preset threshold, it is determined that there is a split wire defect in the area. Automatic detection of split wire defects in carbon fiber yarns through image processing technology can effectively improve detection accuracy and reduce omissions in manual detection, thereby ensuring the quality of carbon fiber products.

[0049] In this embodiment, calculating the inflection point of the pixel point in the complement set includes the following steps:

[0050] Calculate the distance between the two pixels at both ends of the complement set and the straight line, and find the maximum distance value;

[0051] Determine whether the maximum distance value is less than the distance threshold;

[0052] If it is less than, discard all the points between the two ends of the straight line;

[0053] If it is greater than, the pixel point corresponding to the maximum distance value is retained, and this point is used as the inflection point to divide the complement into two parts, and the judgment steps of the maximum distance value and the distance threshold are repeated for the two parts.

[0054] Select the pixel points at both ends in the complement set, connect a straight line through these two pixel points, calculate the vertical distances from all pixel points in the complement set to the straight line, and find the maximum value of these distances. If the maximum distance value is less than the distance threshold, it is considered that there is no obvious inflection point in the complement area, and all the intermediate pixel points between the two ends of the straight line are discarded.

[0055] If the maximum distance value is greater than the distance threshold, the pixel corresponding to the maximum distance value is retained and marked as an inflection point. The complement area is divided into two parts with the inflection point as the boundary, and the above-mentioned maximum distance value and distance threshold judgment steps are repeated for each part to continue to find and mark more inflection points. Through this optimization step, the inflection points in the complement area can be more accurately identified, thereby more reliably detecting the split wire defects in the carbon fiber yarn. This method improves the accuracy of the detection process, reduces the possibility of misjudgment, and ensures the accurate identification of yarn defects.

[0056] As a preferred embodiment of the above, the step of repeatedly using the maximum distance value and the distance threshold for the two parts includes:

[0057] Using the inflection point as the boundary, the complement is divided into two parts;

[0058] Connect the endpoints of the two parts to form a straight line, and determine the distance between all points in the two parts and the straight line, and find the maximum distance value;

[0059] Determine whether the maximum distance value is less than the distance threshold;

[0060] If it is less than, discard all the points between the two ends of the straight line;

[0061] If it is greater than, the pixel point corresponding to the maximum distance value is retained, and this point is used as the inflection point to continue segmenting the part until it can no longer be segmented.

[0062] The inflection point found first is used as the boundary to divide the complement area into two parts, called the left part and the right part. For the left part, connect the starting point of the part and the inflection point to form a straight line. For the right part, connect the inflection point and the end point of the part to form a straight line. For the left part, calculate the vertical distance from all pixels to the straight line and find the maximum distance value. For the right part, also calculate the vertical distance from all pixels to the straight line and find the maximum distance value.

[0063] Determine whether the maximum distance value in the left part is less than the preset distance threshold:

[0064] If it is less than the threshold, it is considered that there is no obvious inflection point in the left part, and all the intermediate pixels between the two ends of the straight line are discarded. If it is greater than the threshold, the pixel corresponding to the maximum distance value is retained and marked as a new inflection point, and the part is continued to be segmented.

[0065] Determine whether the maximum distance value in the right part is less than the preset distance threshold:

[0066] If it is less than the threshold, it is considered that there is no obvious inflection point in the right part, and all the intermediate pixels between the two ends of the straight line are discarded. If it is greater than the threshold, the pixel corresponding to the maximum distance value is retained and marked as a new inflection point, and the part is continued to be segmented.

[0067] For the retained inflection points, the corresponding area is divided into two parts again and the above steps are repeated.

[0068] This process continues until the maximum distance values ​​of all regions are less than the threshold and segmentation is no longer possible.

[0069] Through this recursive segmentation and judgment method, all possible inflection points can be detected more accurately, thereby improving the detection accuracy of split yarn defects. This process ensures that even in complex yarn structures, tiny defects can be effectively identified, ensuring the stability and reliability of product quality.

[0070] The two pixel points at both ends of the complement set are: the two pixel points with the smallest and largest coordinate values ​​on the coordinate axis corresponding to the yarn width direction in the yarn image.

[0071] As a preference for the above embodiment, the gray value threshold range is [1, 125].

[0072] like Figure 5 As shown, this embodiment also includes a carbon fiber splitting detection device, using the above method, the detection device includes:

[0073] An image acquisition unit, used for acquiring a carbon fiber yarn image and converting the yarn image into a grayscale image;

[0074] A region segmentation unit is used to filter out pixels in the grayscale image by grayscale value thresholds, and extract several regions by segmenting connected domains;

[0075] A complement unit is used to find the minimum bounding rectangle of each region and calculate the complement of the region and the minimum bounding rectangle;

[0076] An inflection point calculation unit, used to calculate the inflection points of the pixel points in the complement set and determine the number of inflection points greater than a distance threshold;

[0077] The judging unit is used to judge whether a wire splitting defect exists in the judging area if the number of inflection points exceeds a set number.

[0078] See also Figure 6 A computer device 400 provided in an embodiment of the present application includes: a processor 410 and a memory 420, wherein the memory 420 stores a computer program executable by the processor 410, and when the computer program is executed by the processor 410, the above method is executed.

[0079] The embodiment of the present application further provides a storage medium 430 on which a computer program is stored. When the computer program is run by the processor 410, the above method is executed.

[0080] Among them, the storage medium 430 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable red-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, disk or optical disk.

[0081] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0082] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0084] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0085] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0086] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0087] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0088] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for detecting split carbon fiber, characterized in that: The steps include: Acquire a carbon fiber yarn image, and convert the yarn image into a grayscale image; Filtering out pixels in the grayscale image by using a grayscale value threshold, and extracting a number of regions by segmenting connected domains; Obtaining the minimum bounding rectangle of each of the regions, and calculating the complement of the region and the minimum bounding rectangle; Calculating the inflection points of the pixel points in the complementary set, and determining the number of inflection points greater than a distance threshold; If the number exceeds the set number, it is determined that the area has a split wire defect; The step of calculating the inflection point of the pixel point in the complementary set comprises the following steps: Calculate a straight line connecting two pixel points at both ends of the complement set, calculate the distance between all points in the complement set and the straight line, and find the maximum distance value; Determine whether the maximum distance value is less than the distance threshold; If it is less than, discard all the points between the two ends of the straight line; If it is greater than, the pixel point corresponding to the maximum distance value is retained, and the pixel point is used as the inflection point to divide the complement into two parts, and the judgment steps of the maximum distance value and the distance threshold are repeated for the two parts.

2. The carbon fiber splitting detection method according to claim 1, characterized in that: The step of repeatedly using the maximum distance value and the distance threshold for the two parts comprises: Taking the inflection point as a boundary, dividing the complement set into two parts; Connect the endpoints of the two parts to form a straight line, and determine the distance between all points in the two parts and the straight line, and find the maximum distance value; Determine whether the maximum distance value is less than the distance threshold; If it is less than, discard all the points between the two ends of the straight line; If it is greater than, the pixel point corresponding to the maximum distance value is retained, and this point is used as the inflection point to continue segmenting the part until it can no longer be segmented.

3. The carbon fiber splitting detection method according to claim 2, characterized in that: The two pixel points at both ends of the complementary set are respectively: the two pixel points with the smallest and largest coordinate values ​​on the coordinate axis corresponding to the yarn width direction in the yarn image.

4. The carbon fiber splitting detection method according to claim 1, characterized in that: The gray value threshold range is [1, 125].

5. A carbon fiber splitting detection device, characterized in that: Using the method according to any one of claims 1 to 4, the detection device comprises: An image acquisition unit, used for acquiring a carbon fiber yarn image and converting the yarn image into a grayscale image; A region segmentation unit, used to filter out pixels in the grayscale image by grayscale value threshold, and extract a number of regions by segmenting connected domains; A complement unit, used for obtaining the minimum bounding rectangle of each of the regions, and calculating the complement of the region and the minimum bounding rectangle; An inflection point calculation unit, used to calculate the inflection points of the pixel points in the complement set, and determine the number of inflection points greater than a distance threshold; The judging unit is used to judge whether a wire splitting defect exists in the region if the number of inflection points exceeds a set number.

6. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

7. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

Images