Device and method for double-sided visual detection of surface defects of cloth towel

Abstract

The invention discloses equipment and a method for double-sided visual detection of surface defects of a cloth towel, the equipment comprises a conveying mechanism, a trigger switch, a line scanning camera, a lighting light source and a PLC control system, the conveying mechanism comprises a transparent supporting plate which carries the cloth towel to be detected and conveys the cloth towel in a preset direction, and the transparent supporting plate transmits a signal to the PLC control system when passing through the trigger switch; the four line scanning cameras are triggered to shoot front and back images of the cloth towel passing through the first and second areas according to preset time sequence configuration information, similarity comparison is carried out on an obtained detection image and a cloth towel defect image pre-stored in the system, and whether the cloth towel to be detected is qualified or not is judged. Whether the front side and the back side of the cloth towel are qualified or not is synchronously detected frame by frame, towel turning is not needed, the detection efficiency is doubled, surface and internal flaws of the cloth towel can be detected, and the detection function is improved.

Description

Technical Field

[0001] This invention relates to the field of finishing production of cloths, and in particular to a device and method for double-sided visual inspection of surface defects in cloths. Background Technology

[0002] The finishing process for towels involves first sewing long strips of towel fabric along the longitudinal edges on a longitudinal sewing machine, then cutting them into pieces and sewing them along the transverse edges using a transverse sewing machine, and finally inspecting both sides of the products to ensure they are up to standard before sorting and packaging.

[0003] Manual double-sided inspection is labor-intensive, inefficient, and prone to false positives. The applicant's newly developed "Fabric Visual Inspection Conveyor Line" has been patented (authorization announcement number: CN223426544U). This line first photographs the front of the sewn fabric during transport, then flips it over for a second inspection of the reverse side. The equipment incorporates both inspection and flipping mechanisms, resulting in a long production line and sequential inspection of each side, which reduces efficiency. Furthermore, it can only detect surface defects, failing to detect internal weaving flaws. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a device and method for double-sided visual inspection of surface defects of cloth towels. The transparent tray transports the cloth towels for simultaneous inspection of the front and back sides, which is highly efficient. The front and back light source inspection can detect non-conforming quality problems such as loose threads, skipped threads, and stains on the surface of the cloth towels. The front and back back light source inspection can detect non-conforming quality problems such as internal weaving defects in the cloth towels.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A device for double-sided visual inspection of surface defects in cloth towels, comprising: The conveying mechanism includes a transparent tray that carries the cloth to be inspected along a predetermined direction; A trigger switch, installed on the frame through which the transparent tray passes, is used to transmit information about the transparent tray carrying the cloth to be inspected to the PLC control system. Four line scan cameras are mounted in pairs on the upper and lower frames that the transparent tray passes through sequentially. The lenses face the transparent tray path perpendicularly. The first and third line scan cameras are mounted one after the other on the upper frame, and the second and fourth line scan cameras are mounted one after the other on the lower frame. The first and second line scan cameras are used to capture the front and back images of the cloth to be inspected as it passes through the first area, and the third and fourth line scan cameras are used to capture the front and back images of the cloth to be inspected as it passes through the second area. The lighting sources, including the upper light source and the lower light source, are respectively staggered and installed on the upper and lower racks above and below the transparent tray as it passes through the first and second areas. The PLC control system connects to the trigger switch, the line scan camera, and the drive servo motor of the conveying mechanism. It controls the start, stop, and speed of the servo motor, receives the trigger switch signal, generates the line scan camera capture trigger signal according to the preset timing configuration information, and compares the captured detection image with the pre-stored cloth defect images in the system to determine whether the cloth to be inspected is a qualified or unqualified product.

[0006] A further improvement is that the conveying mechanism includes a transparent tray and a towel feeding linear module. The guide rails of the towel feeding linear module are arranged parallel to each other on both sides. The transparent tray is mounted on the sliders of the towel feeding linear module on both sides, and moves back and forth through the towel feeding linear module.

[0007] A further improvement is that the trigger switch includes a mirror-reflective photoelectric sensor and a reflector, which are respectively installed at corresponding positions on the upper and lower frames along the path of the transparent tray.

[0008] A further improvement is that the transparent tray is made of transparent glass, which provides better light transmission.

[0009] A method for double-sided visual inspection of surface defects in cloth towels is also provided, the steps of which include: The control conveyor mechanism will transport the transparent tray carrying the cloth to be inspected along a predetermined direction; The transparent tray carrying the cloth to be inspected passes through a trigger switch during the conveying process, and the trigger switch signal is transmitted to the PLC control system. According to the preset timing configuration information, the first and second line scanning cameras are controlled to capture front-side positive light source detection images and back-side back light source detection images when the cloth to be inspected passes through the first area, and the third and fourth line scanning cameras are controlled to capture front-side back light source detection images and back-side positive light source detection images when the cloth to be inspected passes through the second area. The detected image is transmitted back to the PLC control system and compared with the pre-stored images of fabric defects to determine whether the fabric to be inspected is a qualified or unqualified product.

[0010] A further improvement is that if each generated detection image achieves a pre-designed similarity with a defect image, the detection image is saved to the PLC control system as a pre-stored defect image. Continuous optimization of the image library leads to more accurate detection.

[0011] A further improvement is that the front positive light source detection image and the back positive light source detection image are used to detect non-conforming quality problems such as loose threads, skipped stitches, and stains on the surface of the towel, while the front back light source detection image and the back back light source detection image are used to detect non-conforming quality problems such as internal weaving defects in the towel.

[0012] Beneficial effects: 1. In this invention, the cloth is placed on a transparent tray for conveying, and linear cameras above and below synchronously detect whether the front and back of the cloth are qualified frame by frame. There is no need to flip the cloth, doubling the detection efficiency. The equipment has a simple structure and a low machine failure rate.

[0013] II. Front and back light source inspection images are used to detect surface defects such as loose threads, skipped stitches, and stains on the fabric. Front and back light source inspection images are used to detect internal weaving defects. This provides more comprehensive detection, automatically identifying both surface and internal flaws, thus enhancing the overall inspection capabilities. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the device structure of the present invention; Figure 2 This is a flowchart of the method of the present invention. Detailed Implementation

[0015] like Figure 1 As shown, the device for double-sided visual inspection of surface defects in cloth towels according to the present invention includes: The conveying mechanism includes a transparent tray 11 (transparent glass plate) and a towel feeding linear module 12. The guide rails of the towel feeding linear module are arranged parallel to each other on both sides. The transparent tray 11 is mounted on the sliders of the towel feeding linear module 12 on both sides. The towel feeding linear module 12 reciprocates and conveys the transparent tray 11 carrying the towel to be inspected along a predetermined direction. The trigger switch includes a mirror-reflecting photoelectric sensor 21 and a reflector 22, which are respectively installed at corresponding positions on the upper and lower frames through which the transparent tray 11 passes, and are used to transmit information about the transparent tray 11 carrying the cloth to be inspected to the PLC control system 5. Four line scanning cameras are installed in pairs on the upper and lower frames that the transparent tray passes through sequentially. The lenses face the transparent tray path vertically. The first line scanning camera 31 and the third line scanning camera 33 are installed one after the other on the upper frame, and the second line scanning camera 32 and the fourth line scanning camera 34 are installed one after the other on the lower frame. The first line scanning camera 31 and the second line scanning camera 32 are used to capture the front and back images of the cloth to be inspected when it passes through the first area 13, and the third line scanning camera and the fourth line scanning camera are used to capture the front and back images of the cloth to be inspected when it passes through the second area 14. The lighting sources, including an upper light source 41 and a lower light source 42, are respectively staggered and installed on the upper frame of the transparent tray 11 as it passes through the first area 13 and the lower frame of the second area 14. The PLC control system 5 connects to the trigger switch, the line scan camera, and the drive servo motor of the conveying mechanism. It controls the start, stop, and speed of the servo motor, receives the trigger switch signal, generates the line scan camera shooting trigger signal according to the preset timing configuration information, and compares the captured detection image with the pre-stored cloth defect images in the system to determine whether the cloth to be inspected is a qualified or unqualified product.

[0016] The working method of the testing equipment is as follows Figure 2 As shown, A method for double-sided visual inspection of surface defects in cloth towels, comprising the following steps: The control conveyor mechanism will transport the transparent tray carrying the cloth to be inspected along a predetermined direction; During the transport of the transparent tray carrying the cloth to be inspected, a trigger switch is passed through it, and the trigger switch signal is transmitted to the PLC control system. The trigger switch includes a mirror-reflective photoelectric sensor 21 and a reflector 22. When the transparent tray carries the cloth to be inspected and passes through the trigger switch, the light emitted by the sensor is blocked by the cloth, thus triggering the signal. When there is no cloth on the transparent tray, no signal is triggered. According to the preset timing configuration information, the first and second line scanning cameras are controlled to capture front-side positive light source detection images and back-side back light source detection images when the cloth to be inspected passes through the first area, and the third and fourth line scanning cameras are controlled to capture front-side back light source detection images and back-side positive light source detection images when the cloth to be inspected passes through the second area. The detected image is transmitted back to the PLC control system and compared with the pre-stored images of fabric defects to determine whether the fabric to be inspected is a qualified or unqualified product.

[0017] The front and back light source detection images are used to detect non-conforming quality issues such as loose threads, skipped stitches, and stains on the surface of the towel. The front and back light source detection images are used to detect non-conforming quality issues such as internal weaving defects in the towel.

[0018] To improve detection efficiency, if each generated detection image achieves a pre-designed similarity with the defect image, the detection image is saved to the PLC control system as a pre-stored defect image.

[0019] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A device for double-sided visual inspection of surface defects in cloth towels, characterized in that, include: The conveying mechanism includes a transparent tray (11) that carries the cloth to be inspected along a predetermined direction; A trigger switch is installed on the frame through which the transparent tray passes, and is used to transmit the information of the transparent tray carrying the cloth to be inspected to the PLC control system (5). Four line scanning cameras are installed in pairs on the upper and lower frames of the transparent tray, with the lenses facing the transparent tray path. The first line scanning camera (31) and the third line scanning camera (33) are installed one after the other on the upper frame, and the second line scanning camera (32) and the fourth line scanning camera (34) are installed one after the other on the lower frame. The first line scanning camera (31) and the second line scanning camera (32) are used to take front and back images of the cloth to be inspected when it passes through the first area (13), and the third line scanning camera and the fourth line scanning camera are used to take front and back images of the cloth to be inspected when it passes through the second area (14). The lighting sources, including the upper light source (41) and the lower light source (42), are respectively staggered and installed on the upper and lower racks of the transparent tray (11) as it passes through the first area (13) and the second area (14); The PLC control system (5) is connected to the trigger switch, the line scan camera and the drive servo motor of the conveying mechanism. It is used to control the start, stop and speed of the servo motor, receive the trigger switch signal, generate the line scan camera shooting trigger signal according to the preset timing configuration information, and compare the similarity of the captured detection image with the pre-stored cloth defect image in the system to determine whether the cloth to be inspected is a qualified product or a non-qualified product.

2. The device for double-sided visual inspection of surface defects in cloth towels according to claim 1, characterized in that: The conveying mechanism includes a transparent tray (11) and a towel feeding linear module (12). The guide rails of the towel feeding linear module are arranged parallel to each other on both sides. The transparent tray is mounted on the sliders of the towel feeding linear module on both sides and moves back and forth through the towel feeding linear module.

3. The device for double-sided visual inspection of surface defects in cloth towels according to claim 1, characterized in that: The trigger switch includes a mirror-reflective photoelectric sensor (21) and a reflector (22), which are respectively installed at corresponding positions on the upper and lower frames through which the transparent tray (11) passes.

4. The device for double-sided visual inspection of surface defects in cloth towels according to claim 1, characterized in that: The transparent tray (11) is a transparent glass plate.

5. A method for double-sided visual inspection of surface defects in cloth towels, characterized in that the steps include... include: The control conveyor mechanism will transport the transparent tray carrying the cloth to be inspected along a predetermined direction; The transparent tray carrying the cloth to be inspected passes through a trigger switch during the conveying process, and the trigger switch signal is transmitted to the PLC control system. According to the preset timing configuration information, the first and second line scanning cameras are controlled to capture front-side positive light source detection images and back-side back light source detection images when the cloth to be inspected passes through the first area, and the third and fourth line scanning cameras are controlled to capture front-side back light source detection images and back-side positive light source detection images when the cloth to be inspected passes through the second area. The detected image is transmitted back to the PLC control system and compared with the pre-stored images of fabric defects to determine whether the fabric to be inspected is a qualified or unqualified product.

6. The method for double-sided visual inspection of surface defects in cloth towels according to claim 5, characterized in that: If each generated detection image achieves a pre-designed similarity with the defective image, the detection image is saved to the PLC control system as a pre-stored defective image.

7. A method for double-sided visual inspection of surface defects in cloth towels according to claim 5, characterized in that: The front and back light source detection images are used to detect non-conforming quality issues such as loose threads, skipped stitches, and stains on the surface of the towel. The front and back light source detection images are used to detect non-conforming quality issues such as internal weaving defects in the towel.

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