Textile yarn knot detection and in-situ repair method and system

Abstract

The invention relates to a detection and in-situ repair method and system for spinning yarn knots, and the method comprises the steps: applying high-frequency vibration to a twisting triangular area of a spinning frame, and separating loose fiber clusters attached to the surfaces of yarns through axial vibration; carrying out polarized light scanning on the surface of the yarn to obtain three-dimensional structure characteristics of the yarn, and identifying a candidate knot area with a sudden diameter change; an instantaneous stress pulse is applied to the candidate knot area, the local elastic response of the yarn is detected, the authenticity of the candidate knot area is judged, real knots show rigidity sudden change, and loose fibers show elastic attenuation; directionally spraying an atomized solvent to the area which is confirmed as a real knot to soften fibers, and meanwhile, applying radial compression force to redirect the fibers to recover the continuity of the yarn; the local temperature distribution of the repaired yarn is detected through infrared thermal imaging, and if the temperature is abnormal, secondary repairing is triggered or the yarn is marked as an unrepairable section. The method effectively solves the problems that a traditional method is high in misjudgment rate and poor in repairing capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of textile processes, and particularly to a method and system for detecting and in-situ repairing knots of textile yarns. Background Art

[0002] As one of the important basic manufacturing industries globally, the quality of yarn directly affects the performance and quality of the final fabric. During the spinning process, after fibers go through processes such as opening, carding, drafting, and twisting, due to uneven fiber lengths or process fluctuations, yarn knots are likely to form. These knots not only reduce the strength uniformity of the yarn but also cause problems such as yarn breakage and weaving defects in subsequent weaving processes, seriously affecting production efficiency and product yield.

[0003] In textile industrial production, the detection and repair of yarn knots have always been key issues affecting product quality and production efficiency. Traditional detection methods mainly rely on optical imaging or tension sensors to identify sudden changes in yarn diameter. However, due to the existence of interference factors such as fiber clusters and hairiness, it is difficult for existing technologies to accurately distinguish real knots from false defects, resulting in a high misjudgment rate. For example: optical detection systems are prone to misjudging temporarily aggregated fiber clusters as knots, while tension sensors may generate false signals due to uneven yarn twist or mechanical vibration.

[0004] With the development of the automation industry, the industry has tried to improve detection accuracy through multi-sensor fusion or machine learning algorithms, but these solutions still have obvious defects; for example, detection methods based on image processing are affected by factors such as lighting conditions and yarn motion blur, and it is difficult to stably extract the three-dimensional structural features of knots; while solutions using mechanical response analysis cannot reliably distinguish the rigid mutation of knots from ordinary twist changes due to the dynamic tension fluctuations of the yarn.

[0005] In addition, existing technologies generally adopt a passive processing mode of "detection - marking - rejection" and lack the ability to in-situ repair real knots, resulting in a reduced effective utilization rate of the yarn. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the detection and repair of yarn knots in the prior art, and provide a method and system for detecting and in-situ repairing knots of textile yarns. By combining high-frequency vibration preprocessing with polarized light scanning and mechanical response detection, the accuracy of yarn knot recognition is significantly improved, and raw material waste is reduced through in-situ repair technology, realizing a closed-loop quality control of detection - repair - verification, and effectively solving the problems of high misjudgment rate and lack of repair ability in traditional methods.

[0007] To solve the above technical problems, the present invention provides a method for detecting and in-situ repairing knots of textile yarns, including the following steps: Apply high-frequency vibration to the twist triangle area of the ring spinning frame, and separate the loose fiber clusters attached to the yarn surface through axial vibration; Perform polarized light scanning on the yarn surface to obtain its three-dimensional structural characteristics and identify candidate knot areas with diameter mutations; Apply an instantaneous stress pulse to the candidate knot area and detect the local elastic response of the yarn to judge the authenticity of the candidate knot area, where: a real knot shows a rigid mutation, while loose fibers show elastic attenuation; For the area confirmed to be a real knot, directionally spray atomized solvent to soften the fibers, and at the same time apply a radial compression force to reorient the fibers and restore the yarn continuity; Pass the repaired yarn through infrared thermal imaging to detect the local temperature distribution. If there is a temperature anomaly, trigger secondary repair or mark it as an irreparable section.

[0008] In an embodiment of the present invention, applying high-frequency vibration to the twist triangle area of the ring spinning frame includes the following steps: Install a high-frequency vibration device in the twist triangle area of the ring spinning frame. The high-frequency vibration device can generate an oblique vibration wave at a set inclination angle with the axial extension direction of the yarn. The oblique vibration wave acts on the yarn to form a composite vibration with both axial propagation and vertical separation effects.

[0009] In an embodiment of the present invention, performing polarized light scanning on the yarn surface to obtain its three-dimensional structural characteristics includes the following steps: Use multiple polarized light sources arranged in a ring to irradiate the yarn from different angles, and at the same time capture the reflected light image of the yarn surface by a high-speed camera; Construct a three-dimensional contour of the yarn surface by analyzing the image differences in different polarization directions; The yarn keeps moving at a constant speed during the scanning process to ensure the continuity of image acquisition.

[0010] In an embodiment of the present invention, applying an instantaneous stress pulse to the candidate knot area and detecting the local elastic response of the yarn includes the following steps: Set a quickly retractable contact probe on the yarn travel path. The contact probe instantaneously presses against the yarn surface under the action of a control signal and quickly withdraws to form a mechanical shock to apply an instantaneous stress pulse to the yarn; Install a force sensor on the contact probe and record the deformation response curve of the yarn in real time through the force sensor to judge the local elastic response of the yarn.

[0011] In an embodiment of the present invention, the atomized solvent spraying is realized by an ultrasonic atomizing nozzle. The ultrasonic atomizing nozzle can swing synchronously with the movement of the yarn. The atomized solvent is a mixture of ethanol and deionized water in a ratio of 1:2, and 0.5-1.5% of fiber softening agent is added.

[0012] In one embodiment of the present invention, the method for applying the radial compression force is as follows: A pair of independently adjustable elastic pressure rollers apply pressure from the upper and lower layers of the yarn. The surface of the elastic pressure rollers is provided with fine grooves to enhance the guiding effect on the wet fibers. The elastic pressure rollers first contact the yarn with a small pressure, then gradually increase to the set pressure and maintain it for a predetermined time, and finally slowly release the pressure.

[0013] In one embodiment of the present invention, when performing infrared thermal imaging detection, an infrared thermal imager and an auxiliary heating source are arranged above the yarn travel path. The infrared thermal imager continuously collects the surface temperature distribution of the yarn in a line scanning manner, and at the same time, the auxiliary heating source uniformly preheats the yarn to enhance the temperature contrast in the defect area.

[0014] In one embodiment of the present invention, when performing infrared thermal imaging detection, a multi-band spectral sensor is used to detect the fiber arrangement uniformity in the repaired area, and the repair quality is comprehensively evaluated in combination with the thermal imaging data.

[0015] In one embodiment of the present invention, after in-situ repair is completed, the yarn tension is gradually adjusted through multiple groups of tension adjustment rollers in the repaired section, so that the tension between the repaired area and the normal yarn section transitions smoothly. During the adjustment process, the yarn deformation is monitored in real time to ensure that no new damage will occur.

[0016] To solve the above technical problems, the present invention also provides a detection and in-situ repair system for textile yarn knots, including: A high-frequency vibration module, which is arranged in the twisting triangle area of the spinning frame and is used to generate axial vibration to separate the loose fiber clusters attached to the yarn surface; A polarized light scanning module, which is used to perform three-dimensional structure scanning on the yarn surface to identify the candidate knot area with a sudden change in diameter; A mechanical response detection module, including a stress application unit and an elasticity detection unit. The stress application unit is used to apply an instantaneous stress pulse to the candidate knot area, and the elasticity detection unit is used to detect the local elastic response of the yarn to judge the authenticity of the knot. Among them, a real knot shows a rigid mutation, and loose fibers show elastic attenuation; An in-situ repair module, including an atomized solvent injection unit and a radial pressure application unit. The atomized solvent injection unit is used to directionally inject solvent to the confirmed real knot area to soften the fibers, and the radial pressure application unit is used to apply a compression force to the softened fibers to reorient them; A quality verification module, which uses infrared thermal imaging technology to detect the local temperature distribution of the repaired yarn and triggers secondary repair or marks the irreparable section according to the temperature anomaly.

[0017] The above technical solution of the present invention has the following advantages compared with the prior art: First, high-frequency vibration is applied in the twist triangle area of the ring spinning frame to actively separate the loose fiber clusters attached to the surface of the yarn through axial vibration. This step effectively reduces the interference signal of subsequent detection and improves the recognition accuracy of real knots. Subsequently, a polarized light scanning technology is used to obtain the three-dimensional structural characteristics of the yarn surface, which can accurately identify the candidate knot area with diameter mutation. In order to further verify the authenticity of the knot, mechanical response detection is introduced: by applying an instantaneous stress pulse in the candidate area and analyzing the local elastic change of the yarn, real knots (manifested as rigid mutation) and temporary fiber aggregation (manifested as elastic attenuation) can be distinguished. This multi-parameter collaborative determination method significantly reduces the misjudgment rate.

[0018] For the confirmed real knots, instead of using the traditional cutting and removing method, this method softens the fibers by directional spraying of atomized solvent and then applies a radial compression force to reorient the fibers, realizing in-situ repair of the knots; this repair method not only retains the original length of the yarn, reduces raw material waste, but also maintains the mechanical continuity of the yarn.

[0019] Finally, infrared thermal imaging is used to verify the quality of the repaired area to ensure that the repair effect meets the requirements of subsequent processing. This closed-loop quality control system fundamentally solves the core problems of high misjudgment rate and lack of repair ability in traditional methods.

[0020] Compared with the prior art, the method for detecting and in-situ repairing textile yarn knots according to the present invention significantly improves the accuracy of knot recognition through vibration preprocessing combined with polarized light scanning and mechanical response detection; moreover, the in-situ repair technology is adopted to reduce yarn loss, improve the utilization rate of raw materials, and ensure the stability and reliability of yarn quality; finally, the repaired yarn is verified twice to guide the subsequent process. The entire process forms a complete closed-loop of detection-repair-verification, providing a new direction for the detection and repair of textile yarn knots and being applicable to the high-end textile production field with strict requirements for yarn quality. Description of the Drawings

[0021] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in conjunction with the drawings, wherein: Figure 1 is the step flow chart of the method for detecting and in-situ repairing textile yarn knots of the present invention; Figure 2 is the structural framework diagram of the system for detecting and in-situ repairing textile yarn knots of the present invention. Detailed Embodiments

[0022] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments given are not intended to limit the present invention.

[0023] Referring to Figure 1 As shown, the method for detecting and in-situ repairing the knots of textile yarns of the present invention includes the following steps: Apply high-frequency vibration to the twisting triangle area of the ring spinning frame to separate the loose fiber clusters attached to the surface of the yarn through axial vibration; during the production process of textile yarns, the twisting triangle area is the key area where the fiber bundle is twisted to form yarn, and it is also the part where the fiber structure is relatively loose and surface fiber cluster aggregation is likely to occur. Traditional methods often directly perform optical detection, but loose fiber clusters are prone to generating false signals, seriously affecting the accuracy of knot recognition. In this embodiment, the fiber clusters loosely attached to the surface of the yarn are separated by mechanical vibration, effectively reducing the interference signals in the subsequent detection process and creating favorable conditions for accurately identifying real knots.

[0024] After the high-frequency vibration pretreatment, the loose fiber clusters on the surface of the yarn have been effectively removed. At this time, precise morphology detection is required to identify potential knot areas. Traditional optical detection methods often rely only on two-dimensional images from a single angle and cannot comprehensively reflect the three-dimensional characteristics of the yarn surface, easily causing misjudgment. Therefore, in this embodiment, the surface of the yarn is scanned with polarized light to obtain its three-dimensional structural characteristics and identify candidate knot areas with diameter mutations. Through this polarized light three-dimensional scanning technology, it is possible to effectively distinguish real fiber entanglement knots from temporary fiber accumulations, significantly improving the accuracy and reliability of knot detection and laying a solid technical foundation for subsequent mechanical verification and in-situ repair.

[0025] There may be situations where the candidate knot areas identified by polarized light scanning have similar morphologies but different structural natures. For example, real fiber entanglement knots and temporary tight fiber accumulations may have similar surface morphologies, but there are essential differences in their mechanical response characteristics. For this reason, this embodiment introduces a mechanical response detection link, applies an instantaneous stress pulse to the candidate knot area, and detects the local elastic response of the yarn to judge the authenticity of the candidate knot area, where: real knots show a rigid mutation, while loose fibers show elastic attenuation; by applying an instantaneous stress at the suspected knot and analyzing its elastic change, the real knot and temporary fiber aggregation are reliably distinguished because real knots will show obvious rigid mutation characteristics, while loose fibers show elastic attenuation.

[0026] After the real knot position is confirmed, it needs to be processed to restore the normal structure of the yarn. The traditional method often uses mechanical cutting to directly remove the defective section. This method not only causes yarn length loss, but also introduces new joint problems. For this reason, this embodiment adopts a repair method of atomized solvent spray softening combined with mechanical compression. For the area confirmed as the real knot, atomized solvent is sprayed in a directional manner to soften the fiber. Although the fibers in the knot area have been softened after being treated with atomized solvent, they still need to be restored to an orderly arrangement through mechanical action to truly eliminate the knot defect. Therefore, radial compression force is applied at the same time to redirect the fibers and restore the continuity of the yarn. After determining the real knot, this embodiment does not use the traditional simple cutting method, but realizes in-situ repair through a process of directional spraying of atomized solvent combined with radial compression force, wherein: solvent softening makes it easier for the fibers at the knot to rearrange, and the compression force prompts the fibers to restore the orderly structure. This method not only retains the original length of the yarn, but also maintains the continuity of its mechanical properties.

[0027] Although the surface morphology of the yarn treated in the above steps has been restored, the bonding state and stress distribution of its internal fibers need to be verified through non-destructive testing. Therefore, the local temperature distribution of the repaired yarn is detected by infrared thermal imaging. If there is a temperature abnormality, a secondary repair is triggered or it is marked as an unrepairable segment. The repair quality is verified by infrared thermal imaging technology, which can sensitively detect possible structural defects or stress concentrations in the repair area, effectively evaluate the repair quality, identify potential internal defects, and provide an objective basis for whether secondary repair is needed.

[0028] In this embodiment, in order to apply high-frequency vibration to the twisting triangle area of ​​the spinning frame, a high-frequency vibration device is installed at the position of the twisting triangle area of ​​the spinning frame, and the high-frequency vibration device can generate an oblique vibration wave with a set inclination angle to the axial extension direction of the yarn. The oblique vibration wave acts on the yarn to form a composite vibration with both axial propagation and vertical separation effects. This vibration design enables the vibration energy to be effectively propagated along the axial direction of the yarn, and at the same time generates sufficient vertical components to act on the surface of the yarn; when this composite vibration acts on the yarn, the axial propagation component ensures that the vibration energy can cover the entire detection area, while the vertical separation component produces a periodic "pulling" effect on the yarn surface, and this plucking effect can effectively loosen and separate loose fiber clusters attached to the surface of the yarn without destroying the main structure of the yarn.

[0029] Specifically, the tilt angle is set to 30° to 60°. If the angle is too small, the vertical separation effect will be insufficient, while if the angle is too large, the axial propagation distance of the vibration energy will be affected.

[0030] Specifically, the high-frequency vibration can be achieved by a piezoelectric ceramic vibrator. The vibration frequency is controlled within the range of 800 - 1500 Hz, the vibration time is set to 0.5 - 2 seconds, and the amplitude is 0.2 - 0.4 mm, enabling the loose fiber clusters to effectively separate from the main body of the yarn without damaging the yarn structure.

[0031] In actual operation, the vibration waves generated by the vibration device continuously propagate along the length direction of the yarn, forming a uniform treatment effect. At the same time, the vibration intensity can be automatically adjusted by real-time monitoring of the yarn tension change to ensure the safety and stability of the treatment process.

[0032] In this embodiment, the multi-angle polarized light scanning technology is adopted. Multiple polarized light sources arranged in a ring illuminate the yarn surface from different directions simultaneously. The wavelength of the light source is set to 400 - 700 nm, and the scanning resolution is 5 - 20 μm. The three-dimensional topography and polarized reflection characteristics of the yarn surface can be obtained synchronously. This all-round illumination method can eliminate the shadow effect caused by a single light source, ensuring that the details of each part of the yarn surface can be fully captured. A high-speed camera is set to synchronously collect the reflected light images under different polarization directions. Since the reflection characteristics of the fibers on the yarn surface are different under different polarized lights, this difference contains rich fiber arrangement information. By analyzing and comparing these image data in multiple angles and polarization states, the precise three-dimensional contour of the yarn surface can be reconstructed. This three-dimensional reconstruction can not only show the change in the yarn diameter but also reflect the fiber orientation and stacking state, providing a more comprehensive topographical basis for accurately identifying the knots.

[0033] It is particularly noteworthy that the yarn needs to maintain a uniform motion throughout the scanning process. This continuous acquisition method avoids the production interruption caused by traditional static detection and ensures the spatio-temporal consistency of the image sequence, providing a high-quality data basis for subsequent image processing and feature extraction.

[0034] In this embodiment, a contact probe with fast response ability is set on the yarn traveling path. Under the command of a precise control system, the probe quickly presses on the yarn surface and immediately withdraws. The duration of the instantaneous stress pulse applied is 1 - 10 ms, and the stress amplitude is 5 - 15% of the yarn breaking strength. This instantaneous mechanical impact simulates the dynamic load that the yarn experiences in actual use and can effectively stimulate the intrinsic mechanical response of the material. A high-sensitivity force sensor installed on the probe records the deformation response curve of the yarn during the force application process in real time. Due to the tight entanglement and stress concentration between fibers, real knots will exhibit obvious rigid characteristics, that is, they generate a large resistance under small deformations. While the temporary fiber accumulation will exhibit progressive elastic deformation characteristics due to its loose structure.

[0035] This identification method based on the intrinsic mechanical properties of materials complements the previous morphology detection, greatly improving the accuracy of knot identification. Moreover, this dynamic detection method causes minimal damage to the yarn. The contact time of the probe is controlled at the millisecond level, and the applied stress is also precisely calculated to ensure that sufficient mechanical response signals can be excited without causing permanent damage to the yarn.

[0036] In this embodiment, the solvent is converted into micron-sized droplets by an ultrasonic atomizing nozzle. The droplets produced by this atomization method have uniform and fine particle sizes, can accurately cover the knot area without spreading to the normal yarn part. A swinging nozzle is set so that it can move synchronously with the moving yarn to ensure that the solvent spray is always aimed at the target position during the whole process.

[0037] Specifically, the atomized solvent is a mixture of ethanol and deionized water, and a fiber softening aid is added. The mixed solvent of ethanol and deionized water has moderate volatility. Ethanol can quickly penetrate the fiber gaps, while water molecules promote the swelling and softening of the fibers. The added trace fiber softening aid can reduce the friction coefficient between the fibers. This composite solvent system can effectively weaken the entanglement binding force between the fibers without damaging the fibers. Ethanol and deionized water are mixed in a ratio of 1:2. The ethanol content ensures the rapid penetration and drying characteristics of the solvent, and the proportion of water ensures a moderate fiber swelling effect. When the atomized solvent acts on the knot area, ethanol molecules first quickly penetrate into the fiber gaps, breaking the hydrogen bond binding between the fibers. Subsequently, water molecules cause the fibers to swell moderately, and the added fiber softening aid further reduces the frictional resistance between the fibers. This synergistic effect makes the originally tightly entangled fibers easy to rearrange. Controlling the content of the fiber softening aid to 0.5 - 1.5% of the total content of the atomized solvent can avoid excessive softening and damage of the fibers.

[0038] In this embodiment, an independently adjustable elastic roller system is adopted to achieve the reorientation of the fibers through a precisely controlled progressive compression process. Two elastic rollers apply pressure synchronously from the upper and lower sides of the yarn. Their elastic properties can automatically adapt to the deformation requirements of yarns with different diameters, avoiding fiber damage that may be caused by rigid extrusion. The carefully designed micro-groove structure on the surface of the elastic rollers can play a guiding role during the compression process. The micro-channels formed by these micro-grooves can guide the softened fibers to be arranged orderly along the axial direction of the yarn. The compression process adopts progressive pressure control. In the initial stage, a small pressure is applied to preliminarily position the fibers to avoid fiber misalignment caused by sudden pressure application. Subsequently, the pressure is gradually increased to the working pressure to ensure sufficient rearrangement of the fibers. Finally, the pressure is slowly released to prevent new structural disorders caused by rapid rebound.

[0039] This staged compression process enables the fibers to complete the rearrangement process smoothly and orderly in the solvent-softened state. The elastic characteristics and surface microstructure of the pressure rollers work together to ensure sufficient compression effect while avoiding mechanical damage to the fibers. The progressive pressure change simulates the ideal manual finishing process.

[0040] In this embodiment, the repair area is continuously scanned and detected by an infrared thermal imager arranged above the yarn travel path, and an auxiliary heating source is set to uniformly preheat the yarn, enabling the overall yarn to reach a stable reference temperature. Due to the differences in fiber arrangement density and heat conduction characteristics between the repair area and the normal yarn segment, these differences will be manifested as subtle temperature distribution changes under the heated state.

[0041] Specifically, the infrared thermal imager uses a line scan method to synchronously capture the temperature field distribution on the yarn surface. Its high-sensitivity detector can identify temperature differences at the 0.1°C level. For areas with imperfect repair, due to the less dense fiber arrangement, their heat conduction efficiency will be lower than that of the normal yarn segment, presenting as local high-temperature areas on the thermal image; while over-compressed areas will show low-temperature areas due to excessive fiber density; the preheating effect of the auxiliary heating source amplifies this heat conduction difference, significantly enhancing the contrast of defect recognition. This detection method is completely non-contact and does not interfere with the yarn operation. The line scan method ensures the continuity of detection and production efficiency, while the temperature contrast enhancement technology greatly improves the detection rate of minor defects.

[0042] Furthermore, infrared thermal imaging can capture temperature anomalies in the repair area, but relying solely on temperature distribution is difficult to comprehensively evaluate the physical reorganization quality of the fiber structure. Therefore, on the basis of infrared thermal imaging, a multi-band spectral sensor is also introduced. The multi-band spectral sensor is used to detect the fiber arrangement uniformity in the repair area, and combined with the thermal imaging data to comprehensively evaluate the repair quality, forming a cooperative detection mechanism with thermal imaging.

[0043] Specifically, after the real knot is repaired, the chemical bond recombination and physical arrangement uniformity of the fibers will simultaneously affect the local optical characteristics and heat conduction performance. The multi-band spectral sensor can capture the spatial distribution differences in fiber orientation angles through the analysis of reflection / scattering characteristics in the visible to near-infrared band (such as 400 - 1700 nm) - when the fibers in the repair area are softened by the solvent and radially compressed, if the arrangement is uniform, the anisotropic optical reflection intensity will show regular changes, while the thermal imaging data reflects the thermal resistance characteristics of the contact density between fibers.

[0044] The data fusion of the two can establish a correlation model between the physical arrangement of fibers and heat conduction. For example, when the fiber orientation in a certain area is detected by spectroscopy to be disordered (manifested as a sudden change in the scattering intensity of multiple bands), this area usually shows a higher thermal resistance (abrupt change in temperature gradient) in thermal imaging because the air gaps between loosely arranged fibers reduce the heat conduction efficiency; when the change trends of the two are consistent (such as a spectral intensity ratio fluctuation > 15% corresponding to a temperature difference > 3°C), it indicates that there is an area in the fiber arrangement where recombination is not sufficient, and the system automatically triggers secondary repair; if only the thermal imaging is abnormal while the spectrum is uniform, it is determined to be a temporary thermal resistance caused by solvent residue, and only marking is required without repair.

[0045] This collaborative detection verifies the repair quality from the dual dimensions of physical structure (spectroscopy) and energy transfer (thermal imaging), avoiding the risk of misjudging the solvent volatilization on the fiber surface as a structural defect by a single detection method, and at the same time accurately locating the physical defect area that requires secondary pressurization through optical anisotropy analysis.

[0046] In actual production, after the repair section undergoes solvent softening and radial compression, there may be a difference in mechanical properties between the bonding state of the fibers in the repair section and that of the normal yarn section - the fibers in the repair area temporarily exhibit a higher internal stress concentration due to recombination. If it runs directly at the normal tension, it may cause secondary fracture or fiber slippage at the junction between the repair area and the normal yarn section due to sudden stress changes.

[0047] To solve the above problems, in this embodiment, after in-situ repair, the yarn tension is gradually adjusted in the repair section through multiple sets of tension adjustment rollers, so that the tension between the repair area and the normal yarn section transitions smoothly. During the adjustment process, the yarn deformation is monitored in real time to ensure that no new damage will occur; the change in yarn tension is essentially achieved through the elastic deformation of molecular chains and the frictional slip between fibers. The viscoelastic response of the fibers in the repair area lags behind that of the normal area. By setting at least three sets of tension adjustment rollers (such as a leading roller, a transition roller, and a stabilizing roller), a stepped tension gradient from the repair area to the normal yarn is formed (such as gradually increasing from 50% of the initial repair tension to 100%), which can make the stress relaxation of the fiber molecular chains synchronize with the increase in tension.

[0048] The specific implementation process includes: the leading roller first reduces the tension in the repair area to 50% of the standard value, at which time the fibers in the repair area complete the initial rebound of molecular chains under low stress; the transition roller increases the tension at a rate of 10% / s, and at the same time, the change in yarn diameter is monitored in real time through a laser micrometer displacement sensor - when it is detected that the deformation rate of a certain section exceeds the preset threshold (such as the diameter shrinkage rate > 0.5% / ms), it indicates that the risk of fiber slippage at this place increases, and the system immediately suspends the tension increase and starts micro-vibration assistance (amplitude < 50μm) to promote fiber re-engagement; the stabilizing roller finally restores the tension to the standard value, and captures the surface tremor frequency of the yarn through a high-frequency camera. If the main frequency of the tremor spectrum deviates from the normal value by more than 5Hz, it is determined that the internal fiber bonding is insufficient and it is necessary to return to the transition roller for readjustment.

[0049] This progressive adjustment avoids the "brittle response" caused by the repair area suddenly bearing full tension through physical buffering. The whole process simulates the stress adaptation mechanism of biological tissues, ensuring that the repair area maintains structural integrity while restoring functional strength.

[0050] To implement the above method, referring to Figure 2 as shown, the present invention also provides a detection and in-situ repair system for textile yarn knots for performing the above method, including: A high-frequency vibration module, arranged in the twisting triangle area of the spinning frame, for generating axial vibration to separate the loose fiber clusters attached to the yarn surface; A polarized light scanning module, for performing three-dimensional structure scanning on the yarn surface to identify candidate knot areas with sudden diameter changes; A mechanical response detection module, including a stress application unit and an elasticity detection unit. The stress application unit is used to apply an instantaneous stress pulse to the candidate knot area, and the elasticity detection unit is used to detect the local elastic response of the yarn to judge the authenticity of the knot. Among them, a real knot shows a rigid mutation, and loose fibers show elastic attenuation; An in-situ repair module, including an atomized solvent injection unit and a radial pressure application unit. The atomized solvent injection unit is used to directionally inject solvent into the confirmed real knot area to soften the fibers, and the radial pressure application unit is used to apply a compressive force to the softened fibers to reorient them; A quality verification module, which uses infrared thermal imaging technology to detect the local temperature distribution of the repaired yarn and triggers secondary repair or marks the irreparable section according to the temperature anomaly.

[0051] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0052] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for detecting and repairing knots in textile yarns in situ, characterized in that: The following steps are involved: Apply high-frequency vibration to the twisting triangle of the spinning frame to separate the loose fiber clusters attached to the yarn surface through axial vibration; Scan the yarn surface with polarized light to obtain its three-dimensional structural features and identify candidate knot areas with sudden diameter changes; Apply an instantaneous stress pulse to the candidate knot area and detect the local elastic response of the yarn to determine the authenticity of the candidate knot area, where: the real knot shows a sudden change in rigidity, while the loose fiber shows elastic attenuation; For the area confirmed as the real knot, atomized solvent is sprayed in a directional manner to soften the fiber, and radial compression force is applied to reorient the fiber and restore the yarn continuity; The repaired yarn is tested for local temperature distribution through infrared thermal imaging. If there is a temperature anomaly, a secondary repair is triggered or the section is marked as unrepairable.

2. The method for detecting and repairing textile yarn knots according to claim 1, characterized in that: Applying high frequency vibration to the twisting triangle of the spinning frame includes the following steps: A high-frequency vibration device is installed in the twisting triangle area of ​​the spinning frame. The high-frequency vibration device can generate an oblique vibration wave with a set inclination angle to the axial extension direction of the yarn. The oblique vibration wave acts on the yarn to form a composite vibration with both axial propagation and vertical separation effects.

3. The method for detecting and repairing textile yarn knots according to claim 1, characterized in that: Scanning the yarn surface with polarized light to obtain its three-dimensional structural characteristics includes the following steps: Multiple polarized light sources arranged in a ring are used to illuminate the yarn from different angles, while a high-speed camera captures the reflected light image of the yarn surface; By analyzing the image differences under different polarization directions, the three-dimensional profile of the yarn surface is constructed; During the scanning process, the yarn keeps moving at a constant speed to ensure the continuity of image acquisition.

4. The method for detecting and repairing textile yarn knots according to claim 1, characterized in that: Applying a transient stress pulse in the candidate knot region and detecting the local elastic response of the yarn includes the following steps: A rapidly retractable contact probe is arranged on the yarn travel path. Under the action of a control signal, the contact probe is pressed against the yarn surface instantly and withdrawn quickly, forming a mechanical shock, thereby applying an instantaneous stress pulse to the yarn. A force sensor is installed on the contact probe, and the deformation response curve of the yarn is recorded in real time by the force sensor to determine the local elastic response of the yarn.

5. The method for detecting and repairing textile yarn knots according to claim 1, characterized in that: The atomized solvent spray is realized by an ultrasonic atomizing nozzle, and the ultrasonic atomizing nozzle can swing synchronously with the movement of the yarn. The atomized solvent is a mixture of ethanol and deionized water in a ratio of 1:2, and 0.5-1.5% of a fiber softening agent is added.

6. The method for detecting and repairing textile yarn knots according to claim 1, characterized in that: The radial compression force is applied by using a pair of independently adjustable elastic pressure rollers to apply pressure from the upper and lower layers of the yarn. The surface of the elastic pressure rollers is provided with micro grooves to enhance the guiding effect on the wet fiber. The elastic pressure rollers first contact the yarn with a small pressure, then gradually increase the pressure to the set pressure and maintain it for a predetermined time, and finally slowly release the pressure.

7. The method for detecting and repairing textile yarn knots according to claim 1, characterized in that: When performing infrared thermal imaging detection, an infrared thermal imager and an auxiliary heating source are arranged above the yarn travel path. The infrared thermal imager continuously collects the yarn surface temperature distribution in a line scanning manner, and the auxiliary heating source uniformly preheats the yarn to enhance the temperature contrast of the defective area.

8. The method for detecting and repairing textile yarn knots according to claim 1, characterized in that: When conducting infrared thermal imaging inspection, a multi-band spectral sensor is used to detect the uniformity of fiber arrangement in the repair area, and the repair quality is comprehensively evaluated in combination with thermal imaging data.

9. The method for detecting and repairing knots in textile yarns according to claim 1, characterized in that: After the in-situ repair is completed, the yarn tension is gradually adjusted in the repair section through multiple sets of tension adjustment rollers to ensure a smooth transition of tension between the repair area and the normal yarn section. The yarn deformation is monitored in real time during the adjustment process to ensure that no new damage occurs.

10. A textile yarn knot detection and in-situ repair system, characterized in that: include: A high-frequency vibration module is arranged in the twisting triangle area of ​​the spinning frame to generate axial vibration to separate loose fiber clusters attached to the yarn surface; Polarized light scanning module, used to perform three-dimensional structural scanning on the yarn surface and identify candidate knot areas with sudden diameter changes; A mechanical response detection module, comprising a stress applying unit and an elasticity detection unit, wherein the stress applying unit is used to apply an instantaneous stress pulse to the candidate knot region, and the elasticity detection unit is used to detect the local elastic response of the yarn to determine the authenticity of the knot, wherein a real knot is manifested as a sudden change in rigidity, and loose fibers are manifested as elastic attenuation; An in-situ repair module comprises an atomized solvent spraying unit and a radial pressure applying unit, wherein the atomized solvent spraying unit is used to spray the solvent in a direction toward the confirmed real knot area to soften the fiber, and the radial pressure applying unit is used to apply a compressive force to the softened fiber to redirect it; The quality verification module uses infrared thermal imaging technology to detect the local temperature distribution of the repaired yarn, and triggers secondary repair or marks the unrepairable section according to the temperature anomaly.

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