Cotton web quality detection system of carding machine

Abstract

The invention relates to a carding machine web quality detection system, which comprises a dielectric plate, an upper surface of which is a smooth convex arc surface; the airflow generating mechanism is used for generating high-speed wall-attached airflow in the tangential direction of the smooth convex cambered surface; the acousto-optic fusion detection module comprises an optical imaging assembly arranged above the dielectric plate and an acoustic emission sensing array attached to the non-contact surface of the dielectric plate; the central control module is respectively connected with the optical imaging assembly and the acoustic emission sensing array and is configured to execute the following detection logics: the optical imaging assembly acquires a web image to identify visible defects, and the acoustic emission sensing array captures stress wave signals generated when hard impurities in the web collide with a dielectric plate under the pressure of wall-attached airflow; and the central control module performs space-time alignment on the image defect coordinates and the stress wave source signal coordinates to generate a web quality distribution diagram. High-speed wall-attached airflow is generated through the variable-curvature dielectric plate, the web is forcibly flattened to eliminate high-speed shaking, and the detection precision is remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of textile processing inspection, and in particular to a cotton web quality inspection system for carding machines. Background Technology

[0002] As the "heart" of the spinning process, the quality of the cotton web produced by the carding machine directly determines the quality of the final yarn. With the development of modern spinning technology towards higher speed and higher output, the sliver output speed of the carding machine has increased significantly, which has brought unprecedented challenges to online quality inspection of the cotton web.

[0003] Existing cotton web quality inspection technologies primarily rely on non-contact scanning using machine vision (such as CCD / CMOS cameras). However, in actual production, due to the extreme thinness of the cotton web and its high-speed movement (up to hundreds of meters per minute), the high-speed airflow disturbance easily causes high-frequency vibrations during transport. This vibration leads to frequent changes in camera focus, resulting in motion blur in the image. This makes it difficult for the inspection system to distinguish between the mesh openings (light-transmitting points) of the cotton web itself and actual holes or defects, leading to misjudgments.

[0004] Furthermore, existing visual inspection systems can only acquire surface morphology information and are often ineffective against hard impurities (such as fine metal wires, hard cotton seed fragments, and plastic pieces) embedded within the cotton web. These "hidden impurities," once they enter subsequent processes, not only cause yarn breakage but also inflict irreversible mechanical damage to expensive drawing frame rollers and carding cloths. Therefore, improvements are needed. Summary of the Invention

[0005] To improve the problems of vibration interference and difficulty in identifying hidden impurities in high-speed cotton web inspection, this application provides a cotton web quality inspection system for carding machines.

[0006] The carding machine web quality inspection system provided in this application adopts the following technical solution: A cotton web quality inspection system for a carding machine, comprising: The medium plate spans across the cotton web conveying path, and its upper surface is a smooth convex arc surface made of light-transmitting material; An airflow generating mechanism, located at the upstream end of the dielectric plate, is used to generate a high-speed wall-attached airflow along the tangential direction of the smooth convex arc surface, so as to adsorb the cotton web and flatten it on the air film layer above the dielectric plate to form a stable detection layer. An acoustic-optical fusion detection module includes an optical imaging component disposed above a dielectric substrate, and an acoustic emission sensing array attached to a non-contact surface of the dielectric substrate; and The central control module, which is connected to the optical imaging component and the acoustic emission sensor array respectively, is configured to execute the following detection logic: the optical imaging component acquires images of the cotton web to identify visible defects; the acoustic emission sensor array captures stress wave signals generated by hard impurities in the cotton web impacting the dielectric plate under the pressure of the attached airflow; and the central control module aligns the coordinates of the image defects with the coordinates of the stress wave source signals in time and space to generate a cotton web quality distribution map.

[0007] Furthermore, it also includes: A pneumatic probe module includes multiple micro-pulse nozzles embedded inside the medium plate, the nozzles having their nozzles penetrating the upper surface of the medium plate and facing the underside of the cotton web. The central control module is also configured to: when the acoustic-optical fusion detection module detects a suspected impurity or cotton knot signal at a certain coordinate point, but the signal confidence level is lower than a preset threshold, control the pulse nozzle at the corresponding coordinate position to spray instantaneous airflow, and also control the optical imaging component to synchronously capture the cotton web morphology changes in the area under disturbance. If the cotton web morphology undergoes loose displacement, it is determined to be fly waste or soft impurity; if the cotton web morphology maintains rigid displacement, it is determined to be hard knot impurity or foreign object.

[0008] Furthermore, the plurality of pulse nozzles include a row of pre-detection nozzles located upstream and several rows of post-processing nozzles located downstream. The spray direction of the pre-detection nozzles forms an angle of 5° to 15° with the normal direction of the cotton web plane, and the spray direction of the post-processing nozzles forms an acute angle with the cotton web conveying direction. The central control module is configured to: control the front detection nozzle to work when an abnormal signal is detected, and control the rear treatment nozzle at the corresponding coordinate position to spray high-frequency continuous airflow when it is determined that the abnormal signal is caused by hard impurities or foreign objects, so as to physically break up the fiber clumps that encapsulate the impurities.

[0009] Furthermore, it also includes: A laser displacement sensor is disposed above the dielectric plate and is positioned opposite the pneumatic probe module. The central control module is also configured to: randomly control the pulse nozzle to spray a fixed amount of standard airflow during normal periods when no abnormal signals are detected, and use the laser displacement sensor to measure the bulging height and rebound time of the cotton web after excitation, thereby calculating the fiber cohesion index of the cotton web.

[0010] Furthermore, the cross-sectional profile of the smooth convex arc surface is an asymmetric arc with a radius of curvature decreasing along the cotton web conveying direction, and its upstream radius of curvature is greater than its downstream radius of curvature. The airflow generating mechanism is a jet slit located at the upstream end of the medium plate, and the jet direction of the jet slit has an angle of less than 15° with the tangential direction of the upstream wall of the smooth convex arc surface.

[0011] Furthermore, the optical imaging assembly includes a CMOS camera, a reflective light source, and a transmissive light source arranged below the dielectric substrate, all pointing towards the cotton web and positioned above the dielectric substrate. The central control module is also configured to: Within a detection cycle, the transmitted light source and the reflected light source are controlled to flash alternately at millisecond intervals, and the CMOS camera is controlled to capture an image frame during each flash. Then, the two consecutive transmission and reflection images are spatially registered at the pixel level to generate a transmission-reflection dual-modal fusion image of the same cotton web area; Based on the ratio of transmitted light density to reflected light intensity of the dual-modal fused image, transparent defects and solid foreign objects in the cotton web are distinguished.

[0012] Furthermore, the acoustic emission sensing array includes multiple piezoelectric ceramic sensors embedded in the side of the dielectric plate opposite to the smooth convex arc surface. The piezoelectric ceramic sensors are surrounded by a damping sleeve that is thin in the middle and thick at the edges, and the edge of the damping sleeve is fixedly connected to the dielectric plate.

[0013] Furthermore, the surface of the medium plate is covered with a micro-textured wear-resistant coating, and the groove direction of the micro-textured wear-resistant coating forms a 45° angle with the direction of movement of the cotton web.

[0014] Furthermore, it also includes: The negative pressure suction port is located at the downstream end of the medium plate and is used to draw in and recover the high-speed attached airflow to prevent the cotton web from drifting again after leaving the detection area due to the wake turbulence.

[0015] In summary, the beneficial technical effects of this application are as follows: 1. A high-speed airflow is generated by a variable curvature medium plate, forming a stable negative pressure adsorption field on the surface of the medium plate. Compared with mechanical pressure plates or simple tension control in the prior art, this application achieves non-contact transmission through an air film layer while forcibly flattening the cotton web to eliminate high-speed shaking. This not only ensures the stability of the optical imaging focal length, but also completely avoids static electricity accumulation and cotton web damage caused by mechanical friction, significantly improving the detection accuracy. 2. To address hidden hard impurities (such as transparent plastics and internal hard seeds) that cannot be identified by visual systems, this application sets a micro-textured wear-resistant coating with 45° grooves on the surface of the dielectric substrate and integrates an acoustic emission array on the back of the dielectric substrate. The micro-textured wear-resistant coating converts the slippage of hard impurities into a high-frequency shear wave with significant characteristics. Combined with a gradient damping sleeve to filter out low-frequency noise in the background, it realizes "stethoscope-like" detection of hidden hard impurities, solves the blind spot of single visual detection, and significantly reduces the false negative rate. 3. By combining pulsed airflow disturbance with laser displacement monitoring, it is possible not only to accurately distinguish between soft cotton knots and hard foreign objects by utilizing the rate of change in the shape of the cotton web, thus solving the problem of false alarms, but also to calculate the fiber cohesion index of the cotton web online based on the stress-strain response, providing a new physical dimension of data support for optimizing carding process parameters, which is difficult to achieve with existing technologies. 4. The optical imaging component generates a dual-modal image of the same area through millisecond-level alternating strobe and pixel-level spatial registration. By using the ratio logic of optical density and reflection intensity, it effectively distinguishes between holes (low optical density and low reflection intensity), solid foreign objects (high optical density and high reflection intensity), and oil stains (high light transmittance and low reflection intensity), further refining the defect classification and improving the granularity of quality analysis. 5. By setting a negative pressure suction port at the end of the medium plate to recover the high-speed wall-attached airflow, the wake turbulence generated when the wall-attached airflow leaves the wall surface is eliminated, ensuring that the cotton web can smoothly transition to the next process after leaving the detection area, preventing secondary drifting caused by interference from the detection airflow, and ensuring the production stability of the entire process. Attached Figure Description

[0016] Figure 1 This is a control logic diagram of the central control module in an embodiment of this application; Figure 2 This is a cross-sectional structural diagram of an embodiment of this application; Figure 3 yes Figure 2 A magnified view of part A in the diagram.

[0017] Explanation of reference numerals in the attached figures: 1. Cotton web; 2. Medium plate; 21. Smooth convex arc surface; 3. Optical imaging components; 31. CMOS camera; 32. Reflective light source; 33. Transmitted light source; 4. Acoustic emission sensor array; 41. Piezoelectric ceramic sensor; 42. Damping sleeve; 5. Pulse nozzle; 51. Pre-detection nozzle; 52. Post-treatment nozzle; 6. Laser displacement sensor; 7. Air jet seams; 8. Negative pressure suction port. Detailed Implementation

[0018] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] This application discloses a cotton web quality inspection system for a carding machine. (Refer to...) Figure 1 - Figure 3 It includes: The medium plate 2 spans across the conveying path of the cotton web 1. Its upper surface is a smooth convex arc surface 21 made of sapphire glass or polycarbonate resin with high light transmittance and a thickness of 5-10mm to withstand the continuous scouring of high-speed airflow. Specifically, the cross-sectional profile of the smooth convex arc surface 21 is an asymmetrical arc with a curvature radius decreasing along the conveying direction of the cotton web 1, and its upstream end curvature radius is greater than its downstream end curvature radius. In a specific example, the upstream end curvature radius R1 = 500-800mm and the downstream end curvature radius R2 = 200-300mm.

[0020] An airflow generating mechanism is located at the upstream end of the medium plate 2. It is used to generate a high-speed wall-attached airflow along the tangential direction of the smooth convex arc surface 21 to adsorb the cotton net 1 and flatten it on the air film layer above the medium plate 2 to form a stable detection layer. Specifically, the airflow generating mechanism is a jet slit 7 opened at the upstream end of the medium plate 2. The jet slit 7 is connected to a high-pressure air source, and the jet direction of the jet slit 7 has an angle of less than 15° with the tangential direction of the upstream end wall of the smooth convex arc surface 21, preferably 5° to 10°.

[0021] The acoustic-optical fusion detection module includes an optical imaging component 3 disposed above the dielectric substrate 2, and an acoustic emission sensing array 4 attached to the non-contact surface of the dielectric substrate 2. Specifically, the optical imaging component 3 includes a CMOS camera 31, all pointing towards the cotton mesh 1 and disposed above the dielectric substrate 2, a reflective light source 32, and a transmissive light source 33 disposed below the dielectric substrate 2; wherein, in a specific example, the optical axis of the lens of the CMOS camera 31 is perpendicular to the smooth convex surface 21, the reflective light source 32 is a red light source, and the transmissive light source 33 is a blue light source. The acoustic emission sensing array 4 includes multiple piezoelectric ceramic sensors 41 embedded in the side of the dielectric substrate 2 away from the smooth convex surface 21 and arranged in an alternating array or a spider web-like radial array, and the acoustic emission sensing array 4 is located upstream of the optical imaging component 3.

[0022] The central control module, connected to the optical imaging component 3 and the acoustic emission sensor array 4 respectively, is configured to execute the following detection logic: the optical imaging component 3 acquires images of the cotton web 1 to identify visible defects; the acoustic emission sensor array 4 captures stress wave signals generated by the impact of hard impurities in the cotton web 1 on the medium plate 2 by the pressure of the attached airflow; and the central control module aligns the image defect coordinates with the stress wave source signal coordinates in time and space to generate a quality distribution map of the cotton web 1.

[0023] Specifically, refer to Figure 1 and Figure 2 The central control module is configured as follows: Within a detection cycle, the transmitted light source 33 and the reflected light source 32 are controlled to flash alternately at millisecond intervals, and the CMOS camera 31 is controlled to acquire an image frame during each flash. Then, the two consecutive transmission and reflection images are spatially registered at the pixel level to generate a transmission-reflection dual-modal fused image of the same cotton web 1 region; Based on the ratio of transmitted light density ODt to reflected light intensity Iᵣ in the dual-modal fusion image, transparent defects and solid foreign objects in cotton web 1 are distinguished.

[0024] Specifically, cloud-like spots (sparse fiber areas) correspond to low ODt (good light transmission), low Iᵣ (weak reflection), and ODt / Ir → medium; solid foreign objects (such as plastic sheets) correspond to high ODt (blocking light transmission), high Iᵣ (specular reflection), and ODt / Ir → high; holes correspond to extremely high ODt (complete light transmission), extremely low Iᵣ, and ODt / Ir → extremely high. Therefore, by setting the ODt / Ir threshold, transparent defects and solid foreign objects can be accurately distinguished, solving the problem of misjudgment in existing technologies.

[0025] Therefore, when the cotton web 1 on the production line is transported to the quality inspection system of this application, the air jet slit 7 sprays high-speed airflow into the smooth convex arc surface 21, and the sprayed high-speed airflow tends to adhere to the smooth convex arc surface 21 and flow; as the radius of curvature of the smooth convex arc surface 21 along the conveying direction of the cotton web 1 gradually decreases, the centrifugal force generated by the high-speed airflow significantly reduces the static pressure near the wall, forming a negative pressure zone; under this negative pressure, the cotton web 1 is tightly "adsorbed" and flattened on a very thin air film layer above the medium plate 2.

[0026] This asymmetric curvature design ensures that the cotton web 1 initially adheres gently to the detection area of ​​the medium plate 2, avoiding impact damage. As it is transported backward, the adhesion gradually increases, ensuring that the cotton web 1 remains absolutely stable and vibration-free in the core detection area. This completely eliminates the high-frequency mechanical vibration of the cotton web 1, providing a constant focal plane for optical imaging. Moreover, the presence of the air film layer prevents the cotton web 1 from directly contacting the medium plate 2, achieving stable transmission with "zero friction." This solves the fundamental problem in traditional detection where the cotton web 1's movement causes image blurring or detection inaccuracies are caused by transmission equipment vibration. At the same time, the continuous scouring of the medium plate 2 by the high-speed airflow also continuously cleans the medium plate 2, preventing residual cotton yarn from contaminating subsequent materials and affecting the light transmittance of the medium plate 2.

[0027] In this way, as the cotton web 1 is adsorbed onto the dielectric plate 2 by the air film layer and passes through the detection area, the acoustic emission sensor array 4 first performs acoustic detection on the cotton web 1. When hard impurities mixed in the cotton web 1 pass through the dielectric plate 2, although there is a buffering effect of the air film layer, under the pressure of high-speed airflow, the hard particles will still penetrate the air film layer instantly and impact or scratch the surface of the dielectric plate 2, exciting high-frequency stress waves. The acoustic emission sensor array 4 can capture this signal and use beamforming algorithms or triangulation methods to calculate the coordinates of the impact point (only the coordinates in the width direction of the cotton web 1 are needed), thereby realizing the online detection and positioning of hard impurities wrapped in the cotton web 1.

[0028] As the cotton web 1 continues to traverse the detection area, within one detection cycle (e.g., 1 ms), the transmitted light source 33 is activated for the first 0.5 ms, and the camera 31 captures the first frame; the reflected light source 32 is activated for the next 0.5 ms, and the camera 31 captures the second frame. Using the movement speed and time interval of the cotton web 1, the displacement deviation is calculated, and then pixel-level spatial registration is performed on the two frames. Based on the ratio of the transmitted light density ODt to the reflected light intensity Iᵣ of the dual-modal fused image, and using the aforementioned determination method, transparent defects and solid foreign objects in the cotton web 1 can be quickly distinguished, thus solving the misjudgment problem of existing technologies.

[0029] In addition, refer to Figure 1 and Figure 2 The quality inspection system of this application also includes: The pneumatic probe module includes multiple micro pulse nozzles 5 embedded inside the medium plate 2, with the nozzles 5 penetrating the upper surface of the medium plate 2 and facing the abdomen of the cotton web 1. The central control module is also configured to: when the acoustic-optical fusion detection module detects a suspected impurity or cotton knot signal at a certain coordinate point, but the signal confidence level is lower than the preset threshold, control the pulse nozzle 5 at the corresponding coordinate position to spray instantaneous airflow, and also control the optical imaging component 3 to simultaneously capture the morphological changes of the cotton web 1 in the area under disturbance. If the morphology of the cotton web 1 is loosened and displaced, it is determined to be fly waste or soft impurity. If the morphology of the cotton web 1 maintains rigid displacement, it is determined to be hard knot impurity or foreign object.

[0030] The acoustic emission sensor array 4 employs a triangulation method or beamforming algorithm. By calculating the time difference between the arrival times of the stress wave generated by the same impact at different piezoelectric ceramic sensors 41, it accurately locates the specific coordinates of the latent hard impurity on the lateral width of the dielectric plate 2, and guides the pulse nozzle 5 corresponding to that coordinate for targeted injection. The specific algorithm is existing technology and can be fully implemented by those skilled in the art, so it needs no further explanation. Moreover, the coordinates of the impurity calculated by the acoustic emission sensor array 4 through the algorithm can also be mapped by the central control module onto the optical image captured by the optical imaging component 3, enabling dual acoustic and optical confirmation of the impurity coordinates.

[0031] In order to improve the efficiency of subsequent processes in handling abnormal points in the cotton web 1, in other feasible embodiments, the multiple pulse nozzles 5 include a row of pre-detection nozzles 51 located upstream and several rows of post-processing nozzles 52 located downstream. The spray direction of the pre-detection nozzles 51 is at an angle of 5° to 15° with the normal direction of the plane of the cotton web 1, and the spray direction of the post-processing nozzles 52 is at an acute angle with the conveying direction of the cotton web 1. The central control module is configured to: control the front detection nozzle 51 to work when an abnormal signal is detected, and control the rear treatment nozzle 52 at the corresponding coordinate position to spray high-frequency continuous airflow when the abnormal signal is determined to be caused by hard impurities or foreign objects, so as to physically break up the fiber clumps that encapsulate the impurities; or control the rear treatment nozzle 52 at the corresponding coordinate position to spray high-frequency continuous airflow after the acoustic emission sensor array 4 detects hard impurities.

[0032] Therefore, when the acoustic-optical fusion detection module identifies a low-confidence defect, since both the optical imaging component 3 and the acoustic emission sensor array 4 can calculate the defect coordinates, the central control module can immediately control the pulse nozzle 5 at that point to spray an instantaneous airflow and control the CMOS camera 31 to take a picture for re-inspection. If the point is blown away or displaced by the airflow (loose displacement), it indicates that it is an attached fly ash, which belongs to the false defect identified by the optical imaging component 3; if the point remains still or moves as a whole, that is, a rigid displacement occurs, it indicates that it is a tightly entangled cotton knot or hard impurity, which belongs to the true defect identified by the optical imaging component 3 or the acoustic emission sensor array 4. This perturbation verification method simulates the authenticity of manual touch inspection, but avoids the complexity of manual re-inspection and greatly reduces the false alarm rate.

[0033] Furthermore, if the defect is identified as hard clumps or foreign matter, the post-treatment nozzle 52 in the pulse nozzle 5 also sprays a high-frequency continuous airflow, using the airflow shearing force to physically break up the fiber clumps that encapsulate the impurities, making the impurities easier to remove in subsequent processes, or at least reducing their "clumping" impact on the needle cloth.

[0034] Furthermore, refer to Figure 1 and Figure 2 To achieve diversified quality monitoring of the high-speed cotton web 1.

[0035] In another feasible embodiment, the quality inspection system of this application further includes: The laser displacement sensor 6 is positioned above the dielectric plate 2 and opposite to the pneumatic probe module. The central control module is also configured to: randomly control the pulse nozzle 5 to spray a fixed amount of standard airflow during normal periods when no abnormal signals are detected, and use the laser displacement sensor 6 to measure the bulging height and rebound time of the cotton web 1 after being excited, thereby calculating the fiber cohesion index of the cotton web 1.

[0036] In a specific example, the central control module records the reference distance H0 of the cotton web 1 relative to the transparent medium plate 2 under the action of high-speed wall-attached airflow when no pulsed airflow is injected. When the pulse nozzle 5 injects airflow, the laser displacement sensor 6 measures the instantaneous maximum displacement distance H of the cotton web 1. max The central control module is based on ΔH=H max -H0 calculates the local dynamic modulus of cotton web 1, thereby characterizing the physical cohesion between fibers in cotton web 1. Specifically, the shorter the rebound time and the smaller ΔH, the stronger the fiber cohesion in cotton web 1, achieving online quantitative evaluation of the physical properties of cotton web 1, which is completely impossible with existing visual inspection methods.

[0037] In addition, to improve the accuracy of the quality inspection system of this application in detecting impurities in cotton web 1.

[0038] In another feasible embodiment, refer to Figure 2 and Figure 3 The piezoelectric ceramic sensor 41 is surrounded by a damping sleeve 42 that is thin in the middle and thick at the edges. The edge of the damping sleeve 42 is fixedly connected to the dielectric plate 2. Furthermore, the surface of the dielectric plate 2 with a smooth convex arc surface 21 is covered with a micro-textured wear-resistant coating (not shown in the figure). The groove direction of the micro-textured wear-resistant coating is at a 45° angle to the movement direction of the cotton web 1.

[0039] Therefore, when hard impurities in the cotton web 1 scratch the dielectric plate 2, they mainly excite high-frequency in-plane shear waves, while the normal sliding of the cotton web 1 generates low-frequency bending waves. The damping sleeve 42 with gradient damping can selectively attenuate the bending waves through impedance matching; furthermore, the grooves of the micro-textured wear-resistant coating at a 45° angle can also cause the hard impurities to generate micro-cutting vibrations, which can be separated from the background noise frequency band, and the presence of hard impurities in the cotton web 1 can be converted and amplified into identifiable low-noise acoustic features, thereby significantly improving the detection accuracy of hard impurities in the cotton web 1. In addition, the grooves of the micro-textured wear-resistant coating can capture tiny impurity particles in the cotton web 1, preventing them from scratching the needle cloth again; while the damping sleeve 42 attenuates the bending waves, it also isolates the structural vibration noise of the dielectric plate 2, further reducing the detection error.

[0040] Furthermore, to prevent the high-speed cotton web 1 from drifting secondary due to the wake turbulence of the high-speed attached airflow after leaving the medium plate 2, thus affecting the quality of the preceding detection, refer to... Figure 2 The quality inspection system of this application also includes: The negative pressure suction port 8 is located at the downstream end of the medium plate 2 and is used to draw and recover the high-speed wall-attached airflow. The negative pressure suction port 8 is connected to a vacuum pump, and the negative pressure suction volume of the vacuum pump is matched with the flow rate of the air jet slit 7, so that a quasi-closed airflow circulation is formed in the detection area, which maintains the stability of the air film and does not interfere with the downstream cotton web 1 conveying.

[0041] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A cotton web quality inspection system for a carding machine, characterized in that, include: The medium plate spans across the cotton web conveying path, and its upper surface is a smooth convex arc surface made of light-transmitting material; An airflow generating mechanism, located at the upstream end of the dielectric plate, is used to generate a high-speed wall-attached airflow along the tangential direction of the smooth convex arc surface, so as to adsorb the cotton web and flatten it on the air film layer above the dielectric plate to form a stable detection layer. The acoustic-optical fusion detection module includes an optical imaging component disposed above the dielectric substrate and an acoustic emission sensing array attached to the non-contact surface of the dielectric substrate. as well as The central control module, which is connected to the optical imaging component and the acoustic emission sensor array respectively, is configured to execute the following detection logic: the optical imaging component acquires images of the cotton web to identify visible defects; the acoustic emission sensor array captures stress wave signals generated by hard impurities in the cotton web impacting the dielectric plate under the pressure of the attached airflow; and the central control module aligns the coordinates of the image defects with the coordinates of the stress wave source signals in time and space to generate a cotton web quality distribution map.

2. The carding machine web quality detection system according to claim 1, characterized in that, Also includes: A pneumatic probe module includes multiple micro-pulse nozzles embedded inside the medium plate, the nozzles having their nozzles penetrating the upper surface of the medium plate and facing the underside of the cotton web. The central control module is also configured to: when the acoustic-optical fusion detection module detects a suspected impurity or cotton knot signal at a certain coordinate point, but the signal confidence level is lower than a preset threshold, control the pulse nozzle at the corresponding coordinate position to spray instantaneous airflow, and also control the optical imaging component to synchronously capture the cotton web morphology changes in the area under disturbance. If the cotton web morphology undergoes loose displacement, it is determined to be fly waste or soft impurity; if the cotton web morphology maintains rigid displacement, it is determined to be hard knot impurity or foreign object.

3. The carding machine web quality detection system according to claim 2, characterized in that, The plurality of pulse nozzles include a row of pre-detection nozzles located upstream and several rows of post-processing nozzles located downstream. The spray direction of the pre-detection nozzles forms an angle of 5° to 15° with the normal direction of the cotton web plane, and the spray direction of the post-processing nozzles forms an acute angle with the cotton web conveying direction. The central control module is configured to: control the front detection nozzle to work when an abnormal signal is detected, and control the rear treatment nozzle at the corresponding coordinate position to spray high-frequency continuous airflow when it is determined that the abnormal signal is caused by hard impurities or foreign objects, so as to physically break up the fiber clumps that encapsulate the impurities.

4. The carding machine web quality detection system according to claim 2, characterized in that, Also includes: A laser displacement sensor is disposed above the dielectric plate and is positioned opposite the pneumatic probe module. The central control module is also configured to: randomly control the pulse nozzle to spray a fixed amount of standard airflow during normal periods when no abnormal signals are detected, and use the laser displacement sensor to measure the bulging height and rebound time of the cotton web after excitation, thereby calculating the fiber cohesion index of the cotton web.

5. The carding machine web quality detection system according to claim 1, characterized in that, The cross-sectional profile of the smooth convex arc surface is an asymmetric arc with a radius of curvature decreasing along the direction of the cotton web conveying, and the radius of curvature at its upstream end is greater than that at its downstream end. The airflow generating mechanism is a jet slit located at the upstream end of the medium plate, and the jet direction of the jet slit has an angle of less than 15° with the tangential direction of the upstream wall of the smooth convex arc surface.

6. The carding machine web quality detection system according to claim 1, characterized in that, The optical imaging assembly includes a CMOS camera, a reflective light source, and a transmissive light source, all pointing towards the cotton web and arranged above the dielectric substrate; The central control module is also configured to: Within a detection cycle, the transmitted light source and the reflected light source are controlled to flash alternately at millisecond intervals, and the CMOS camera is controlled to capture an image frame during each flash. Then, the two consecutive transmission and reflection images are spatially registered at the pixel level to generate a transmission-reflection dual-modal fusion image of the same cotton web area; Based on the ratio of transmitted light density to reflected light intensity of the dual-modal fused image, transparent defects and solid foreign objects in the cotton web are distinguished.

7. The carding machine web quality detection system according to claim 1, characterized in that, The acoustic emission sensing array includes multiple piezoelectric ceramic sensors embedded in the side of the dielectric plate away from the smooth convex arc surface. The piezoelectric ceramic sensors are surrounded by a damping sleeve that is thin in the middle and thick at the edges. The edge of the damping sleeve is fixedly connected to the dielectric plate.

8. The carding machine web quality detection system according to claim 7, characterized in that, The surface of the medium plate is covered with a micro-textured wear-resistant coating, and the groove direction of the micro-textured wear-resistant coating forms a 45° angle with the direction of movement of the cotton web.

9. The carding machine web quality detection system according to claim 1, characterized in that, Also includes: The negative pressure suction port is located at the downstream end of the medium plate and is used to draw in and recover the high-speed attached airflow to prevent the cotton web from drifting again after leaving the detection area due to the wake turbulence.

Images