A method and system for detecting and in-situ repairing knots of textile yarns

Abstract

The present invention relates to a method and system for detecting and in-situ repairing knots of textile yarns. High-frequency vibration is applied in the twist triangle area of a ring spinning frame to separate loose fiber clusters attached to the yarn surface through axial vibration. The yarn surface is scanned with polarized light to obtain its three-dimensional structural characteristics and identify candidate knot areas with sudden diameter changes. An instantaneous stress pulse is applied to the candidate knot areas, and the local elastic response of the yarn is detected to judge the authenticity of the candidate knot areas, where: real knots show a rigid mutation, while loose fibers exhibit elastic attenuation. For the areas confirmed to be real knots, atomized solvent is sprayed directionally to soften the fibers, and at the same time, a radial compression force is applied to reorient the fibers and restore the continuity of the yarn. The repaired yarn is detected for the local temperature distribution through infrared thermal imaging. If there is a temperature anomaly, secondary repair is triggered or it is marked as an irreparable section. The present invention effectively solves the problems of high false positive rate and lack of repair ability in traditional methods.

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 fluctuation 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] To address the above technical problems, 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. Through high-frequency vibration preprocessing combined 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:

[0008] Apply high-frequency vibration in the twist triangle area of the ring spinning frame to separate the loose fiber clusters attached to the yarn surface through axial vibration;

[0009] Perform polarized light scanning on the yarn surface to obtain its three-dimensional structural characteristics and identify the candidate knot regions with diameter mutations;

[0010] Apply an instantaneous stress pulse in the candidate knot region and detect the local elastic response of the yarn to judge the authenticity of the candidate knot region, where: the real knot shows a rigid mutation, while the loose fiber shows elastic attenuation;

[0011] For the region confirmed to be a real knot, directionally spray atomized solvent to soften the fiber, and at the same time apply a radial compression force to reorient the fiber and restore the yarn continuity;

[0012] 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.

[0013] In an embodiment of the present invention, applying high-frequency vibration in the twist triangle area of the ring spinning frame includes the following steps:

[0014] 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.

[0015] 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:

[0016] 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;

[0017] Construct the three-dimensional contour of the yarn surface by analyzing the image differences in different polarization directions;

[0018] The yarn moves at a constant speed during the scanning process to ensure the continuity of image acquisition.

[0019] In an embodiment of the present invention, applying an instantaneous stress pulse in the candidate knot region and detecting the local elastic response of the yarn includes the following steps:

[0020] Set a quickly retractable contact probe on the yarn traveling 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;

[0021] A force sensor is installed on the contact probe, and the deformation response curve of the yarn is recorded in real time through the force sensor to judge the local elastic response of the yarn.

[0022] In one embodiment of the present invention, the atomized solvent injection 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 aid is added.

[0023] 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 smaller pressure, then gradually increase to the set pressure and maintain it for a predetermined time, and finally slowly release the pressure.

[0024] 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 traveling 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.

[0025] 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 repair area, and the repair quality is comprehensively evaluated in combination with the thermal imaging data.

[0026] In one embodiment of the present invention, after in-situ repair is completed, the yarn tension is gradually adjusted through multiple groups of tension adjusting rollers in the repair section, so that the tension between the repair area and the normal yarn section is smoothly transitioned. During the adjustment process, the yarn deformation is monitored in real time to ensure that no new damage is generated.

[0027] To solve the above technical problems, the present invention also provides a detection and in-situ repair system for textile yarn knots, including:

[0028] 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 surface of the yarn;

[0029] A polarized light scanning module, which is used to perform three-dimensional structure scanning on the surface of the yarn to identify the candidate knot area with a sudden change in diameter;

[0030] 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, the real knot shows a rigid mutation, and the loose fiber shows an elastic attenuation;

[0031] In-situ repair module, including an atomized solvent injection unit and a radial pressure application unit. The atomized solvent injection unit is used to direct the injection of solvent to 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;

[0032] 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.

[0033] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0034] First, high-frequency vibration is applied in the twisting triangle area of the spinning frame to actively separate the loose fiber clusters attached to the yarn surface through axial vibration. This step effectively reduces the interference signal of subsequent detection and improves the recognition accuracy of real knots. Subsequently, polarized light scanning technology is used to obtain the three-dimensional structural characteristics of the yarn surface, which can accurately identify the candidate knot areas with diameter mutations. In order to further verify the authenticity of the knots, mechanical response detection is introduced: by applying an instantaneous stress pulse in the candidate area and analyzing the local elastic changes of the yarn, real knots (manifested as rigid mutations) and temporary fiber aggregations (manifested as elastic attenuation) can be distinguished. This multi-parameter collaborative determination method significantly reduces the misjudgment rate.

[0035] For the confirmed real knots, this method does not adopt the traditional cutting and removing method, but softens the fibers by directionally injecting atomized solvent and then applies a radial compressive force to reorient the fibers, realizing the 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.

[0036] Finally, the quality of the repaired area is verified by infrared thermal imaging 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.

[0037] Compared with the prior art, the method for detecting and in-situ repairing textile yarn knots described in 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 raw material utilization rate, 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 production field of high-end textiles with strict requirements for yarn quality. Description of the Drawings

[0038] 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 accompanying drawings, where:

[0039] Figure 1 is the step flow chart of the detection and in-situ repair method for the textile yarn knot of the present invention;

[0040] Figure 2 is the structural framework diagram of the detection and in-situ repair system for the textile yarn knot of the present invention. Specific Embodiments

[0041] The following further illustrates the present invention 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 exemplified embodiments do not limit the present invention.

[0042] Referring to Figure 1 as shown, the detection and in-situ repair method for the textile yarn knot of the present invention includes the following steps:

[0043] Apply high-frequency vibration to the twisting triangle area of the ring spinning frame, and separate the loose fiber clusters attached to the yarn surface 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 yarns, 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 likely to generate false signals, seriously affecting the accuracy of knot recognition. In this embodiment, the fiber clusters loosely attached to the yarn surface are separated by mechanical vibration, effectively reducing the interference signals in the subsequent detection process and creating favorable conditions for accurately identifying real knots.

[0044] After the high-frequency vibration pretreatment, the loose fiber clusters on the yarn surface 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 yarn surface 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.

[0045] In the candidate knot region identified by polarized light scanning, there may be cases where the surface morphologies are similar but the structural essences are different. For example, a real fiber entanglement knot and a temporary tight fiber packing may exhibit similar surface morphologies, but there are essential differences in mechanical response characteristics. Therefore, in this embodiment, a mechanical response detection link is introduced. An instantaneous stress pulse is applied to the candidate knot region, and the local elastic response of the yarn is detected to judge the authenticity of the candidate knot region. Among them: a real knot shows 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 the temporary fiber aggregation are reliably distinguished because the real knot will exhibit obvious rigid mutation characteristics, while the loose fibers show elastic attenuation.

[0046] After confirming the position of the real knot, it is necessary to process it to restore the normal structure of the yarn. Traditional methods often directly remove the defective section by mechanical cutting. This method not only causes loss of yarn length but also introduces new joint problems. Therefore, in this embodiment, a repair method combining atomized solvent spraying softening and mechanical compression is adopted. For the region confirmed as a real knot, atomized solvent is directionally sprayed to soften the fibers. Although the fibers in the knot region after atomized solvent treatment have been softened, mechanical action is still required to make them return to an orderly arrangement to truly eliminate the knot defect. Therefore, a radial compression force is applied simultaneously to reorient the fibers and restore the yarn continuity; in this embodiment, after determining the real knot, instead of using the traditional simple cutting method, in-situ repair is achieved through the process of directionally spraying atomized solvent combined with radial compression force. Among them: solvent softening makes the fibers at the knot more easily rearranged, while the compression force promotes the fibers to restore an orderly structure. This method not only retains the original length of the yarn but also maintains the continuity of its mechanical properties.

[0047] Although the surface morphology of the yarn processed through the foregoing steps has been restored, the bonding state and stress distribution of its internal fibers need to be verified through non-destructive testing. Therefore, the repaired yarn is passed through infrared thermal imaging to detect the local temperature distribution. If there is a temperature anomaly, secondary repair is triggered or it is marked as an irreparable section; the repair quality is verified through infrared thermal imaging technology. This technology can sensitively detect possible structural defects or stress concentrations in the repair region, can effectively evaluate the repair quality, identify potential internal defects, and provide an objective basis for whether secondary repair is needed.

[0048] 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.

[0049] 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.

[0050] 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, so that the loose fiber clusters are effectively separated from the yarn body without damaging the yarn structure.

[0051] In actual operation, the vibration waves generated by the vibration device continue to propagate along the length of the yarn, forming a uniform treatment effect. At the same time, the vibration intensity can be automatically adjusted by real-time monitoring of yarn tension changes to ensure the safety and stability of the treatment process.

[0052] In this embodiment, a multi-angle polarized light scanning technology is adopted. Multiple polarized light sources arranged in a ring are used to simultaneously illuminate the yarn surface from different directions. The wavelength of the light source is set to 400-700nm, and the scanning resolution is set to 5-20μm. The three-dimensional morphology and polarized reflection characteristics of the yarn surface can be synchronously obtained. This omnidirectional lighting 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 reflected light images under different polarization directions. Since the reflection characteristics of the fibers on the yarn surface under different polarized lights are different, this difference contains rich fiber arrangement information; by analyzing and comparing these multi-angle and multi-polarization state image data, the accurate three-dimensional contour of the yarn surface can be reconstructed. This three-dimensional reconstruction can not only show the change in yarn diameter, but also reflect the direction and stacking state of the fibers, providing a more comprehensive morphological basis for accurately identifying knots.

[0053] It is particularly noteworthy that the yarn needs to maintain a uniform motion throughout the scanning process. This continuous acquisition method avoids production interruptions caused by traditional static detection, while ensuring the spatio-temporal consistency of the image sequence, providing a high-quality data basis for subsequent image processing and feature extraction.

[0054] In this embodiment, a contact probe with fast response ability is set on the yarn traveling path. Under the command of a precision control system, the probe performs a quick point pressure on the yarn surface and immediately withdraws. The duration of the applied instantaneous stress pulse 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 receives during actual use, and can effectively stimulate the intrinsic mechanical response of the material. The highly sensitive 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 temporary fiber accumulations will exhibit progressive elastic deformation characteristics due to their loose structure.

[0055] This identification method based on the intrinsic mechanical properties of the material 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 it can stimulate sufficient mechanical response signals without causing permanent damage to the yarn.

[0056] In this embodiment, the solvent is converted into micron-sized droplets through an ultrasonic atomization nozzle. The droplets produced by this atomization method are uniform and fine in size, and 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, ensuring that the solvent injection is always aimed at the target position throughout the processing.

[0057] Specifically, the atomized solvent is a mixture of ethanol and deionized water, with a fiber softening aid added. The mixed solvent of ethanol and deionized water has moderate volatility. Ethanol can quickly penetrate into 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 an appropriate 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 easier to rearrange. Controlling the content of the fiber softening aid to 0.5 - 1.5% of the total atomized solvent content can avoid excessive softening and damage of the fibers.

[0058] 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 possible fiber damage caused by rigid extrusion. The carefully designed micro-groove structure on the surface of the elastic rollers can generate a guiding effect 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 smaller pressure is applied to preliminarily position the fibers, avoiding fiber misalignment caused by sudden pressure application. Subsequently, the pressure is gradually increased to the working pressure to ensure full rearrangement of the fibers. Finally, the pressure is slowly released to prevent new structural disorders caused by rapid rebound.

[0059] This staged compression process enables the fibers to complete the rearrangement process smoothly and orderly in the solvent-softened state. The synergistic effect of the elastic properties and surface micro-structure of the rollers not only ensures sufficient compression effect but also avoids mechanical damage to the fibers. The progressive pressure change simulates an ideal manual finishing process.

[0060] In this embodiment, an infrared thermal imager arranged above the yarn travel path continuously scans and detects the repair area, 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.

[0061] Specifically, the infrared thermal imager uses a line-scanning method to synchronously capture the temperature field distribution on the surface of the yarn. Its highly sensitive detector can identify temperature differences at the 0.1°C level. For areas with imperfect repair, due to the less dense arrangement of fibers, the heat conduction efficiency will be lower than that of normal yarn segments, presenting as local high-temperature areas on the thermal image; while over-compressed areas will show low-temperature areas due to the excessive fiber density; the preheating effect of the auxiliary heating source amplifies this heat conduction difference, significantly enhancing the contrast for defect identification. This detection method is completely non-contact and does not interfere with the yarn operation. The line-scanning method ensures the continuity and production efficiency of the detection, while the temperature contrast enhancement technology greatly improves the detection rate of minor defects.

[0062] Furthermore, infrared thermal imaging can capture temperature anomalies in the repair area, but it is difficult to comprehensively evaluate the physical reorganization quality of the fiber structure solely based on the temperature distribution. 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 collaborative detection mechanism with thermal imaging.

[0063] Specifically, after the repair of real knots, the chemical bond recombination and physical arrangement uniformity of the fibers will simultaneously affect the local optical properties and heat conduction performance. The multi-band spectral sensor can capture the spatial distribution differences in the fiber orientation angle through the analysis of the 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.

[0064] The data fusion of the two can establish a correlation model between fiber physical arrangement and heat conduction. For example, when the spectral detection shows that the fiber orientation in a certain area is disordered (manifested as a sudden change in multi-band scattering intensity), this area usually shows a higher thermal resistance (a sharp change in temperature gradient) in the thermal image. This is because the air gap between the loosely arranged fibers reduces the heat conduction efficiency. When the change trends of the two are consistent (such as a fluctuation in the spectral intensity ratio > 15% corresponding to a temperature difference > 3°C), it indicates that there is an area where the fiber arrangement has not been fully reorganized, 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.

[0065] This collaborative detection verifies the repair quality from the dual dimensions of physical structure (spectrum) and energy transfer (thermal imaging), avoiding the risk of misjudging the solvent evaporation on the fiber surface as a structural defect by a single detection method. At the same time, it accurately locates the physical defect areas that require secondary pressurization through optical anisotropy analysis.

[0066] In actual production, after the repaired section is softened by a solvent and radially compressed, there may be mechanical property differences in the bonding state between fibers compared to normal yarn sections - the fibers in the repaired area temporarily exhibit a higher internal stress concentration due to recombination. If it is directly run at a normal tension, it may cause secondary fracture or fiber slippage at the junction between the repaired area and the normal yarn section due to sudden stress changes.

[0067] To solve the above problems, in this embodiment, after in-situ repair is completed, the yarn tension is gradually adjusted through multiple groups of tension adjustment rollers in the repaired section, enabling a smooth transition of the tension between the repaired area and the normal yarn section. During the adjustment process, the yarn deformation is monitored in real-time to ensure that no new damage is generated; 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 repaired area lags behind that of the normal area. By setting at least three groups of tension adjustment rollers (such as a leading roller, a transition roller, and a stabilizing roller), a stepped tension gradient from the repaired area to the normal yarn is formed (such as gradually increasing from 50% of the initial repair tension to 100%), which can synchronize the stress relaxation of fiber molecular chains with the increase in tension.

[0068] The specific implementation process includes: The leading roller first reduces the tension in the repaired area to 50% of the standard value. At this time, the fibers in the repaired 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 a 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.

[0069] This progressive adjustment avoids the "brittle response" of the repaired area caused by suddenly bearing the full tension through physical buffering. The whole process simulates the stress adaptation mechanism of biological tissues, ensuring that the repaired area maintains structural integrity while restoring functional strength.

[0070] 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, used to execute the above method, including:

[0071] A high-frequency vibration module, arranged in the twist triangle area of the spinning frame, used to generate axial vibration to separate loose fiber clusters attached to the yarn surface;

[0072] A polarized light scanning module, used to perform three-dimensional structure scanning on the yarn surface to identify candidate knot areas with sudden diameter changes;

[0073] The mechanical response detection module includes a stress application unit and an elasticity detection unit. The stress application unit is used to apply an instantaneous stress pulse to the candidate joint area, and the elasticity detection unit is used to detect the local elastic response of the yarn to judge the authenticity of the joint. Among them, a real joint shows a rigid mutation, and loose fibers show elastic attenuation.

[0074] The in-situ repair module includes an atomized solvent injection unit and a radial pressure application unit. The atomized solvent injection unit is used to directionally inject a solvent to soften the fibers in the confirmed real joint area, and the radial pressure application unit is used to apply a compressive force to the softened fibers to reorient them.

[0075] 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 irreparable section according to the temperature anomaly.

[0076] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. 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 memory, CD-ROM, optical memory, etc.) containing computer-usable program code.

[0077] Obviously, the above embodiments are only examples 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 list 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 in-situ repairing knots of textile yarns, characterized in that: It includes the following steps: Apply high-frequency vibration in the twisting triangle area of the ring spinning frame to separate the loose fiber clusters attached to the yarn surface; Perform polarized light scanning on the yarn surface to obtain its three-dimensional structural characteristics and identify the candidate knot areas with diameter mutations; Apply an instantaneous stress pulse in 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; Among them: applying high-frequency vibration in the twisting triangle area of the ring spinning frame includes the following steps: install a high-frequency vibration device in the twisting triangle area of the ring spinning frame. The high-frequency vibration device can generate an oblique vibration wave that forms 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; the vibration frequency of the high-frequency vibration is controlled within the range of 800 - 1500 Hz, set the vibration time to 0.5 - 2 seconds, and the amplitude to 0.2 - 0.4 mm, so that the loose fiber clusters can effectively detach from the yarn body without damaging the yarn structure; The method for applying the radial compression force is: use 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 fibers. The elastic pressure rollers first contact the yarn with a smaller pressure, then gradually increase to the set pressure and maintain it for a predetermined time, and finally slowly release the pressure.

2. The method for detecting and in-situ repairing the knot of the textile yarn according to claim 1, wherein: 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 the three-dimensional contour of the yarn surface by analyzing the image differences in different polarization directions; During the scanning process, the yarn moves at a constant speed to ensure the continuity of image acquisition.

3. The method for detecting and in-situ repairing the knot of a textile yarn according to claim 1, characterized in that: Applying an instantaneous stress pulse in 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 impact 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.

4. The method for detecting and in-situ repairing the knot of a textile yarn according to claim 1, characterized in that: The atomized solvent spraying is realized by an ultrasonic atomizing nozzle, and the ultrasonic atomizing nozzle can swing synchronously with the movement of the yarn.

5. The detection and in-situ repair method of the textile yarn knot according to claim 1, characterized in that: When performing infrared thermal imaging detection, arrange an infrared thermal imager and an auxiliary heating source above the yarn travel path. The infrared thermal imager continuously collects the temperature distribution on the yarn surface in a line scanning manner, and at the same time the auxiliary heating source preheats the yarn evenly to enhance the temperature contrast of the defect area.

6. The method for detecting and in-situ repairing the knot of a textile yarn according to claim 1, wherein: When performing infrared thermal imaging detection, a multi-band spectral sensor is used to detect the fiber arrangement uniformity in the repair area, and the repair quality is comprehensively evaluated by combining the thermal imaging data.

7. The method for detecting and in-situ repairing the knot of a textile yarn according to claim 1, wherein: After in-situ repair is completed, the yarn tension is gradually adjusted through multiple sets of tension adjustment rollers in the repair section, 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 is generated.

8. A system for implementing the method for detecting and in-situ repairing the knots of textile yarns according to any one of claims 1 to 7 above, characterized in that: It includes: A high-frequency vibration module, which is arranged in the twisting triangle area of the spinning frame, generates 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; the vibration frequency of the high-frequency vibration 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, so that the loose fiber clusters can effectively break away from the yarn body without damaging the yarn structure; A polarized light scanning module, which is used to perform three-dimensional structure scanning on the yarn surface to identify candidate knot areas with sudden diameter changes; A mechanical response detection module, which includes 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, which includes 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. The radial pressure application unit uses 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 roller is provided with fine grooves to enhance the guiding effect on the wet fibers. The elastic pressure roller first contacts the yarn with a small pressure, then gradually increases to the set pressure and maintains it for a predetermined time, and finally slowly releases the pressure, which 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.

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