Protection window fouling detection device and method for laser welding equipment

Abstract

The invention discloses a protection window fouling detection device and method for laser welding equipment. The detection device comprises a protection window lens mounting assembly, a cushion block, a supporting wall, a detection assembly and a housing. The protection window lens mounting assembly comprises a field lens connecting ring, a lens mounting ring, a lamp strip, a protection window lens and a pressing ring; the field lens connecting ring is mounted at the upper end in the lens mounting ring in an angle-adjustable manner; the lamp strip is embedded in a lamp strip groove in the inner side wall of the installation ring and located below the field lens connecting ring. The pressing ring presses the protection window lens on the outer side of the lamp strip groove, so that a light source of the lamp strip enters from the peripheral wall of the protection window lens; one end of the support wall is connected with the outer side of the lens mounting ring through a cushion block; the detection assembly is installed in the housing and comprises an imaging assembly, a color filter installation assembly and a camera protection lens installation assembly which are sequentially arranged in the light path direction. According to the invention, the position and the size of contamination can be accurately identified, the lens of the protection window can be quickly replaced, and the welding efficiency and the yield are improved.

Description

Technical Field

[0001] This invention relates to a device and method for detecting contamination on a protective window of a laser welding equipment, belonging to the technical field of laser welding equipment. Background Technology

[0002] With the development of new energy battery technology, laser welding equipment has basically replaced traditional welding equipment for processing and production. Laser welding has high precision and controllable penetration depth, which improves the efficiency of enterprise production lines.

[0003] Protective window lenses generally refer to the lower protective lenses of scanning lenses in laser processing, including cutting, welding, marking, and cleaning. To protect the internal optical path and core components, protective window lenses are installed on laser galvanometer scanning lenses. Dust and spatter generated on the workpiece surface during operation can severely damage the focusing lens if they enter the lens; protective window lenses prevent this dust and spatter from entering. The cleanliness of the protective window lens directly affects the processing performance and quality of the laser. If the lens is dirty, it will not only affect the welding effect and yield, but may also cause the internal components of the galvanometer lens and the laser output head to burn out. Therefore, when the protective window lens becomes dirty during processing, it needs to be cleaned or replaced.

[0004] Currently, the inspection of contamination on protective lenses of laser welding equipment mainly relies on periodic visual checks by operators, requiring processing to be stopped and waiting. Furthermore, due to subjective factors, the criteria for judging the degree of contamination vary, making traditional visual inspection methods time-consuming, labor-intensive, and inconsistent in standards. Summary of the Invention

[0005] To address the shortcomings of traditional visual inspection technologies, this invention provides a device and method for detecting contamination on protective window lenses in laser welding equipment. Its purpose is to accurately locate the position and degree of contamination on the protective window lens, allowing for synchronous installation with the field lens without affecting the existing laser processing production line. This improves the line's operating speed, avoids the subjective influence of human visual inspection, and enables timely cleaning or replacement of the protective window lens, thereby improving the quality of welded products and reducing the welding defect rate.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A device for detecting contamination of a protective window in a laser welding equipment includes a protective window lens mounting assembly, a pad, a support, a detection assembly, and a housing. The protective window lens mounting assembly includes a field lens connecting ring, a lens mounting ring, a light strip, a protective window lens, and a clamping ring; The field lens connecting ring is installed at an adjustable angle on the upper inner side of the lens mounting ring; the inner wall of the lens mounting ring below the field lens connecting ring is provided with a light strip groove along the periphery, and the light strip is embedded in the light strip groove; the clamping ring presses the protective window lens onto the outside of the light strip groove, so that the light source of the light strip enters from the peripheral wall of the protective window lens. The cover is a hollow cylindrical structure. One end of the support wall is connected to the outer wall of the lens mounting ring through a pad, and the other end is connected to the outer wall of the cover. The detection component is installed inside the housing. The detection component includes an imaging component, a color filter mounting component, and a camera protective lens mounting component arranged sequentially along the optical path. The camera protective lens mounting component is located at one end of the housing, and the other end of the housing is sealed by a tail panel. The camera protective lens mounting component faces the protective window lens.

[0007] The aforementioned clamping ring works in conjunction with the lens mounting ring to clamp and protect the window lens.

[0008] The fit between the various ring structures in this application can be achieved by means of threaded fit or other methods.

[0009] The aforementioned camera protective lens mounting assembly includes a first pressure ring, a protective lens, a rubber ring, and a protective lens mounting base. The first pressure ring cooperates with the protective lens mounting base to press the protective lens tightly. The rubber ring is sandwiched between the protective lens and the protective lens mounting base to seal the internal space of the detection assembly. The protective lens mounting base is connected to the side wall of the housing by screws.

[0010] The aforementioned camera protective lens mounting assembly prevents welding spatter from entering the interior of the testing device.

[0011] The above-mentioned filter mounting assembly includes a second pressure ring, a filter, and a filter mounting base. The second pressure ring cooperates with the filter mounting base to press the filter tightly. The imaging assembly includes a circuit board, a camera and a camera base. The circuit board is fixed to the inner wall of the housing with screws. The light strip is connected to the circuit board through a wire. The camera and the camera base are fixed with screws. The camera base is fixed to the inner wall of the housing with screws. Finally, the tail plug panel covers the rear end of the housing and is connected to the housing with screws. The filter mount can be fitted onto the front of the camera lens.

[0012] The second pressure ring has the same size and structure as the first pressure ring.

[0013] The aforementioned LED strip is connected to a circuit board, which then connects to an industrial computer via a wire outlet slot on the tail panel. The circuit board communicates with the host computer via a serial port to control the LED strip's on / off state. The circuit board utilizes existing mature technology, and this application does not offer any significant improvements; therefore, further details are omitted.

[0014] The aforementioned camera includes a lens and an industrial camera, with the lens and industrial camera connected via a C-mount thread.

[0015] The wavelengths of the LED light source and the narrowband color filter can be adjusted according to the transmittance curve parameters of the internal lenses of the field lens to avoid laser wavelengths as much as possible, thus preventing high-energy laser reflections during processing from damaging the internal sensors of the camera. Preferably, the color filter is a 650nm narrowband color filter; the wavelength of the LED beads on the light strip is 650nm.

[0016] A set screw can be added to the side wall of the optical lens mounting ring as needed.

[0017] For ease of installation, the aforementioned LED strip groove is U-shaped with its opening facing upwards. The height of the groove is parallel to the axis of the lens mounting ring. Light-emitting holes are distributed along the periphery of the groove to position the LED beads on the strip. That is, each LED bead is located within its respective light-emitting hole, which facilitates quick installation and positioning, and also ensures the stability of the device during use.

[0018] To improve the stability of the device and ensure the lighting effect, a flange is provided on the inner wall of the lens mounting ring below the field lens connecting ring and above the lamp strip groove. The protective window lens is sandwiched between the flange and the clamping ring. The clamping ring is threaded to the lower end of the lens mounting ring to clamp the protective window lens, and the periphery of the protective window lens is attached to the outer wall of the lamp strip groove. After the clamping ring is tightened, the center of the peripheral wall of the protective window lens is basically aligned with the center of the LED beads on the lamp strip, ensuring that the light emitted by the LED beads on the lamp strip enters from the peripheral wall of the protective window lens.

[0019] The aforementioned flange and the groove for the light strip are provided with space for the installation of the light strip.

[0020] The upper end of the above-mentioned field lens connecting ring extends beyond the lens mounting ring, and the outer wall of the (upper end of the field lens connecting ring) is threaded, which is used to connect the field lens. This field lens connecting ring is used to replace the pressure ring of the field lens protective window lens. The lower end of the field lens connecting ring has screw mounting holes for connecting with the lens mounting ring. The outer peripheral wall of the lens mounting ring has spaced horizontal waist-shaped holes, which are fixed to the screw holes on the outer peripheral wall of the field lens connecting ring by half-thread screws. The relative position of the lens mounting ring and the field lens connecting ring can be adjusted by loosening the half-thread screws.

[0021] To facilitate imaging and inspection, the aforementioned support wall includes a first mounting surface and a second mounting surface with an included angle of 120° to 160°. The outer wall of the lens mounting ring is mounted on the back end of the first mounting surface via a pad. The cover is adjustablely mounted on the back side of the second mounting surface. The height can be adjusted by providing multiple mounting holes or oblong holes, thereby enabling adjustment of the camera position.

[0022] The aforementioned light strip is circular, and the field lens connecting ring, lens mounting ring, light strip, and clamping ring are all concentrically arranged.

[0023] A method for detecting contamination of a protective window lens for laser welding equipment, wherein the above-mentioned protective window contamination detection device for laser welding equipment is used to inspect the field lens connecting ring and the protective window lens that were not pre-installed on the lens mounting ring; include: 1) Install the upper end of the field lens connecting ring 2 onto the field lens of the laser welding equipment by threading. After the lens mounting ring is placed on the field lens connecting ring, adjust the angle of the field lens connecting ring relative to the lens mounting ring and lock it with a half-thread screw. Then install the cleaned or brand-new protective window lens onto the lens mounting ring. 2) When the light strip is turned on, the light will be reflected multiple times inside the protective window lens and captured by the imaging component as the reference imaging data; 3) During the laser welding equipment processing operation, the light strip is turned on at regular intervals. The light is used to detect dirt on the surface of the protective window lens by reflecting it multiple times inside the lens. The imaging component is used to take pictures as the operation imaging data. 4) Compare and analyze the running imaging data with the reference imaging data. The reference imaging data is used as background noise. Calculate the pixel grayscale value of the image after removing the background noise from the running imaging data. When the grayscale value and the dirty area reach the preset value, determine the location and degree of dirt on the protective window lens. Clean or replace the protective window lens by removing and installing the fastening ring. Otherwise, if the grayscale value and the dirty area do not reach the preset value, continue to use the protective window lens.

[0024] Step 4) above employs an N×N grid-based regional strategy: for each sub-region, based on the typical grayscale anomalies (darker or brighter than surrounding areas) exhibited by contaminants (such as dust, scratches, stains, etc.), differentiated grayscale threshold ranges and contamination area values ​​are set to achieve accurate extraction of contaminants from different regions. This regional processing mechanism can adaptively compensate for spatial variations in the optical properties of the lens surface, significantly improving the accuracy of contaminant detection in complex scenarios.

[0025] The core principle of detecting dirt on the lens surface by utilizing multiple reflections of light inside the protective window lens is to amplify the interference effect of dirt on light propagation, combined with changes in the reflection, scattering, and absorption characteristics of light to achieve detection. The specific process can be broken down into the following points: 1. Amplification effect of multiple reflections: Protective window lenses typically have a highly transparent parallel planar structure. When light is incident at a specific angle, it undergoes multiple reflections between the inner and outer surfaces of the protective window, forming a multiple reflection optical path. This design allows light to come into contact with the lens surface (or the inner surface of the protective window) multiple times. Even tiny dirt will accumulate and affect the light through these multiple interactions, thereby amplifying differences in the detection signal and improving sensitivity.

[0026] 2. Regular reflection characteristics of a clean surface: When the lens surface is clean, the reflection of light within the protective window follows the laws of specular reflection (the direction and intensity of the reflected light are stable), and most light rays can undergo multiple reflections along a fixed path;

[0027] 3. Scattering and Absorption of Light by Dirt: When dirt (such as dust particles, oil stains, scratches, etc.) is present on the lens surface, it disrupts the regular reflection of light. Scattering: The irregular surface of dirt causes light to scatter in all directions (Mi scattering); Absorption: Dirt (especially dark or sticky stains) absorbs some of the incident light. Different distributions of dirt and scattering together form light spots of different shapes;

[0028] 4. Signal Analysis and Contamination Assessment: Industrial cameras can infer the degree of contamination by detecting parameters such as the intensity and distribution of scattered light. The more severe the contamination (larger area, higher concentration), the stronger the intensity of the scattered light, and the more obvious the light signal and its shape received by the camera; the distribution of the scattered light directly corresponds to the location of the contaminant on the lens surface.

[0029] In this application, during the processing of laser welding equipment, the light strip light source is turned on and the industrial camera takes a picture at unit time intervals, and the picture is used as the operation imaging data.

[0030] By adjusting the camera exposure parameters, imaging data of pollutants of different levels can be captured. Increasing the exposure time of industrial cameras can reveal fine dust particles in the image. Image recognition has the advantage of high dynamic range.

[0031] This application compares and analyzes the running imaging data with the reference imaging data, using the reference imaging data as background noise. The image after removing the background noise from the running imaging data is calculated for pixel grayscale values. When the grayscale value and the dirty area reach a preset value, the location and degree of dirt on the protective window lens are determined. The protective window lens can then be cleaned or replaced by removing and installing the clamping ring. Otherwise, the protective window lens continues to be used.

[0032] The core principle of this image detection algorithm is based on a three-order processing logic of "benchmark comparison - region masking - domain extraction", which is described in detail below: Using a clean lens image as a baseline template, the highlight areas of the light in the image are first extracted through grayscale threshold analysis. The core of this step is to take advantage of the fact that there is no contaminant interference in the clean lens to accurately locate the inherent highlight distribution (usually manifested as a high grayscale value area) formed by the light on the lens surface and mark it as the "non-detection area" that needs to be excluded.

[0033] Subsequently, the extracted light areas are used as masks to perform spatial masking on the contaminated lens image: the masking operation removes the light highlights in the contaminated lens that are identical to those in the clean lens, leaving only the "potentially abnormal areas" where contaminants may exist. This step effectively eliminates ambient light interference such as direct light and reflection, focusing on the areas where contaminants may actually exist.

[0034] Considering the spatial heterogeneity of optical properties in different regions of the lens (such as differences in illumination intensity and reflectivity between the edge and center regions), the algorithm further employs an N×N grid-based regionalization strategy: for each sub-region, based on the typical grayscale anomalies (darker or brighter than surrounding areas) exhibited by contaminants (such as dust, scratches, stains, etc.), differentiated grayscale threshold ranges and contamination area values ​​are set to achieve accurate extraction of contaminants from different regions. This regionalization mechanism can adaptively compensate for spatial variations in the optical properties of the lens surface, significantly improving the accuracy of contaminant detection in complex scenarios.

[0035] Overall, the algorithm achieves the goal of efficiently separating and identifying pollutants from complex backgrounds through three levels: benchmark image calibration, interference region masking, and domain threshold adaptation, while taking into account both robustness and accuracy of detection.

[0036] Any techniques not mentioned in this invention are based on existing technologies.

[0037] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a protective window contamination detection device for laser welding equipment. When preventing contamination of the internal lens of the laser welding equipment's field lens, one end of the field lens connecting ring is screwed tightly onto the field lens, and a lens mounting ring is fitted onto the field lens connecting ring. A clean protective window lens is then installed on the contamination detection device. The protective window lens on the contamination detection device enables the field lens to prevent contamination (if contaminants are sputtered onto the protective window lens, welding can continue by replacing the protective window lens). The first imaging data of the clean protective window lens after the light strip is turned on is then recorded as baseline imaging data for comparison with the operational imaging data collected during subsequent processing.

[0038] During laser welding, after the previous processing step is completed and before the next step, a light strip light source is turned on and an industrial camera captures operational imaging data. When sputtered contaminants appear on the protective window lens, the light strip light source on the side wall of the protective window reflects multiple times inside, causing Mie scattering at the contaminants on the lens surface. The light scattered by the contaminants is then incident on the target surface of the industrial camera through the lens, forming an image. Contaminants of different areas will form light spots of different sizes, and contaminants of different thicknesses will form light spots with different grayscale values. Finally, based on the comparison and processing of the baseline imaging data and the operational imaging data, the difference in grayscale values ​​at the same location in both images is analyzed to identify the location and size of the contaminants. When a preset value is reached, a warning is issued, prompting the cleaning or replacement of the protective window lens. At this point, simply unscrewing the clamping ring of the protective window lens is sufficient for cleaning or replacement, thus improving the efficiency of contamination detection and cleaning. Otherwise, the protective window lens continues to be used.

[0039] In summary, the present invention provides a protective window contamination detection device for laser welding equipment, which can not only accurately identify the location and size of contamination and avoid the influence of subjective factors caused by visual observation, but also realize the quick cleaning and replacement of the protective window lens, thereby improving the efficiency of laser welding production line and the welding yield. Attached Figure Description

[0040] Figure 1 This is a magnified schematic diagram of the optical path of the light source undergoing multiple reflections inside the lens as described in this invention. Figure 2 This is a schematic diagram illustrating how an industrial camera captures scattered light from dirt on a protective window lens, as described in this invention. Figure 3 These are images taken by an industrial camera in the device of this invention; Figure 4 This is an image showing the effect of the present invention after comparing the running imaging data with the reference imaging data and then performing area masking during image processing; Figure 5 This is a diagram showing the effect of image processing on the imaging data obtained by the present invention. Figure 6 This is a schematic diagram of the structure of a protective window contamination detection device for laser welding equipment provided in an embodiment of the present invention; Figure 7 This is an exploded view of a protective window contamination detection device for laser welding equipment provided in an embodiment of the present invention; Figure 8 This is a flowchart of a method for detecting contamination on a protective window of a laser welding equipment, provided by an embodiment of the present invention. Detailed Implementation

[0041] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0042] The directional terms in this application, such as "center," "vertical," "horizontal," "length," "width," "thickness," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," are based on the appendix. Figure 6-7 The relative orientations or positional relationships shown are for the purpose of describing this application only, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] Example 1

[0044] like Figure 6-7 As shown, a protective window contamination detection device for laser welding equipment includes a protective window lens mounting assembly, a pad, a support wall, a detection assembly, and a cover. The protective window lens mounting assembly includes a field lens connecting ring 1, a lens mounting ring 2, a light strip 3, a protective window lens 4, and a clamping ring 5; The field lens connecting ring 1 is installed at an adjustable angle on the upper inner side of the lens mounting ring 2; the inner wall of the lens mounting ring 2 below the field lens connecting ring 1 is provided with a light strip groove along the periphery, and the light strip 3 is embedded in the light strip groove; the clamping ring 5 presses the protective window lens 4 onto the outside of the light strip groove, so that the light source of the light strip 3 enters from the periphery of the protective window lens 4. The cover is a hollow cylindrical structure. One end of the support wall is connected to the outer wall of the lens mounting ring 2 through a pad, and the other end is connected to the outer wall of the cover. The detection component is installed inside the housing. The detection component includes an imaging component, a color filter mounting component, and a camera protective lens mounting component arranged sequentially along the optical path. The camera protective lens mounting component is located at one end of the housing, and the other end of the housing is sealed by the tail panel 19. The camera protective lens mounting component faces the protective window lens 4.

[0045] Example 2

[0046] Based on Example 1, the following improvements were made: Figure 7 As shown, the camera protective lens mounting assembly includes a first pressure ring 7, a protective lens 8, a rubber ring 9, and a protective lens mounting base 10. The first pressure ring 7 cooperates with the protective lens mounting base 10 to press the protective lens 8 tightly. The rubber ring 9 is sandwiched between the protective lens 8 and the protective lens mounting base 10 to seal the internal space of the detection assembly. The protective lens mounting base 10 is connected to the side wall of the housing by screws. The camera protective lens mounting assembly prevents welding spatter from entering the interior of the detection device.

[0047] Example 3

[0048] Based on Example 2, the following improvements were made: Figure 7 As shown, the above-mentioned filter mounting assembly includes a second pressure ring 11, a filter 12, and a filter mounting base 13. The second pressure ring 11 and the filter mounting base 13 cooperate to press the filter 12. The imaging assembly includes a circuit board 16, a camera 17, and a camera base 18. The circuit board 16 is fixed to the inner wall of the housing 15 with screws. The light strip 3 is connected to the circuit board 16 through a circuit. The camera 17 and the camera base 18 are fixed to each other with screws. The camera base 18 is fixed to the inner wall of the housing 15 with screws. Finally, the tail panel 19 covers the rear end of the housing and is connected to the housing with screws. The filter mounting base 13 can be fitted onto the front end of the lens of the camera 17. The second pressure ring 11 and the first pressure ring 7 are of the same size and structure. The light strip 3 is connected to the circuit board. The circuit board leads wires to the industrial control computer through the wire outlet hole on the tail panel and communicates with the host computer through the serial port to control the lighting and extinguishing of the light strip. The camera system includes a lens and an industrial camera. The lens and industrial camera are connected via a USB-C threaded connection. The industrial camera transmits captured images to an industrial computer for analysis via USB or Ethernet. Color filter 12 is a 650nm narrowband color filter; the LED beads on the light strip 3 have a wavelength of 650nm.

[0049] Example 4

[0050] Based on Embodiment 3, the following improvements were made: For ease of installation, the aforementioned LED strip groove is U-shaped with its opening facing upwards. The height direction of the LED strip groove is parallel to the axial direction of the lens mounting ring 2. Light-emitting holes are distributed along the periphery of the LED strip groove to position the LED beads on the LED strip 3. That is, each LED bead is located within its respective light-emitting hole, which facilitates quick installation and positioning, and also ensures the stability of the device during use.

[0051] Example 5

[0052] Based on Example 4, the following improvements were made: To enhance the stability of the device while ensuring illumination, a flange is provided on the inner wall of the lens mounting ring 2 below the field lens connecting ring 1 and above the LED strip groove, with the protective window lens 4 sandwiched between the flange and the clamping ring 5. The clamping ring 5 is threadedly connected to the lower end of the lens mounting ring 2 to clamp the protective window lens, and the periphery of the protective window lens 4 is fitted against the outer wall of the LED strip groove. After the clamping ring 5 is tightened, the center of the peripheral wall of the protective window lens 4 is basically aligned with the center of the LED beads on the LED strip 3, ensuring that the light emitted by the LED beads on the LED strip 3 enters from the peripheral wall of the protective window lens 4. A space is reserved between the flange and the LED strip groove for LED strip installation.

[0053] Example 6

[0054] Based on Example 5, the following improvements were made: Figure 6-7 As shown, the upper end of the field lens connecting ring 1 extends beyond the lens mounting ring 2, and the outer wall of the (upper end of the field lens connecting ring 1) is threaded for connecting the field lens. This field lens connecting ring is used to replace the pressure ring of the field lens protective window lens. The lower end of the outer peripheral wall of the field lens connecting ring 1 has screw mounting holes for connecting with the lens mounting ring 1. The outer peripheral wall of the lens mounting ring 2 has horizontally spaced waist-shaped holes, which are fixed to the screw mounting holes of the outer peripheral wall of the field lens connecting ring 1 by half-thread screws. The relative position of the lens mounting ring 2 and the field lens connecting ring 1 can be adjusted by loosening the half-thread screws.

[0055] Example 7

[0056] Based on Example 6, the following improvements were made: Figure 6-7 As shown, for ease of imaging detection, the aforementioned support wall includes a first mounting surface and a second mounting surface with an included angle of 120~160°. The outer wall of the lens mounting ring 2 is mounted on the back end of the first mounting surface via a pad. The housing is adjustablely mounted on the back side of the second mounting surface. The height can be adjusted by providing multiple mounting holes or oblong holes, thereby allowing for camera position adjustment. The light strip 3 is annular, and the field lens connecting ring 1, lens mounting ring 2, light strip 3, and clamping ring 5 are all concentrically arranged.

[0057] A method for detecting contamination of a protective window lens for laser welding equipment, wherein the above-mentioned protective window contamination detection device for laser welding equipment is used to check that the field lens connecting ring 1 and the protective window lens 4 are not pre-installed on the lens mounting ring 2; include: 1) Install the upper end of the field lens connecting ring 2 onto the field lens of the laser welding equipment by threading. After the lens mounting ring is placed on the field lens connecting ring, adjust the angle of the field lens connecting ring 1 relative to the lens mounting ring 2 and lock it with a half-thread screw. Then install the cleaned or brand-new protective window lens 4 onto the lens mounting ring 2. 2) When the light strip 3 is turned on, the light will be reflected multiple times inside the protective window lens 4 and captured by the imaging component as the reference imaging data; 3) During the laser welding equipment processing operation, turn on light strip 3 at regular intervals, such as... Figure 1-2 As shown, dirt on the surface of the protective window lens 4 is detected by multiple reflections of light inside the lens 4, and the imaging component captures the image as operational imaging data. Figure 3 As shown; 4) Compare and analyze the running imaging data with the baseline imaging data, using the baseline imaging data as background noise. Calculate the pixel grayscale values ​​of the images obtained by removing background noise from the running imaging data (see...). Figure 4When the grayscale value and the area of ​​soiling reach a preset value, the location and extent of soiling of the protective window lens 4 are determined. The protective window lens 4 is then cleaned or replaced by removing and installing the fastening ring 5. Otherwise, if the grayscale value and the area of ​​soiling do not reach the preset value, the protective window lens 4 continues to be used. This step employs an N×N grid regional strategy: for each sub-region, based on the typical grayscale anomaly characteristics (darker or brighter than surrounding areas) exhibited by contaminants (such as dust, scratches, stains, etc.), differentiated grayscale threshold ranges and soiling area values ​​are set to achieve accurate extraction of contaminants from different regions. See [link to relevant documentation]. Figure 5 This domain-specific processing mechanism can adaptively compensate for spatial variations in the optical properties of the lens surface, significantly improving the accuracy of contaminant detection in complex scenarios.

[0058] The above-mentioned method achieves the goal of efficiently separating and identifying contaminants from complex backgrounds through three levels: reference image calibration, interference area shielding, and domain threshold adaptation. It balances the robustness and accuracy of detection, avoids the influence of subjective factors caused by visual observation, and enables quick cleaning and replacement of protective window lenses, thereby improving the efficiency of laser welding production lines and the welding yield.

Claims

1. A device for detecting contamination on a protective window of a laser welding equipment, characterized in that: This includes protective window lens mounting components, pads, supports, detection components, and housings; The protective window lens mounting assembly includes a field lens connecting ring, a lens mounting ring, a light strip, a protective window lens, and a clamping ring; The field lens connecting ring is installed at an adjustable angle on the upper inner side of the lens mounting ring; the inner wall of the lens mounting ring below the field lens connecting ring is provided with a light strip groove along the periphery, and the light strip is embedded in the light strip groove; the clamping ring presses the protective window lens onto the outside of the light strip groove, so that the light source of the light strip enters from the peripheral wall of the protective window lens. The cover is a hollow cylindrical structure. One end of the support wall is connected to the outer wall of the lens mounting ring through a pad, and the other end is connected to the outer wall of the cover. The detection component is installed inside the housing. The detection component includes an imaging component, a color filter mounting component, and a camera protective lens mounting component arranged sequentially along the optical path. The camera protective lens mounting component is located at one end of the housing, and the other end of the housing is sealed by a tail panel. The camera protective lens mounting component faces the protective window lens.

2. The protective window contamination detection device for laser welding equipment according to claim 1, characterized in that: The camera protective lens mounting assembly includes a first pressure ring, a protective lens, a rubber ring, and a protective lens mounting base. The first pressure ring cooperates with the protective lens mounting base to press the protective lens tightly. The rubber ring is sandwiched between the protective lens and the protective lens mounting base to seal the internal space of the detection assembly. The protective lens mounting base is connected to the side wall of the housing by screws.

3. The protective window contamination detection device for laser welding equipment according to claim 1 or 2, characterized in that: The filter mounting assembly includes a second pressure ring, a filter, and a filter mounting base. The second pressure ring cooperates with the filter mounting base to press the filter tightly. The imaging assembly includes a circuit board, a camera, and a camera base. The circuit board is fixed to the inner wall of the housing with screws. The light strip is connected to the circuit board via wiring. The camera and the camera base are fixed with screws. The camera base is fixed to the inner wall of the housing with screws. The tail plug panel covers the rear end of the housing and is connected to the housing with screws. The color filter mounting bracket is installed on the front of the camera lens.

4. The protective window contamination detection device for laser welding equipment according to claim 3, characterized in that: The color filter is a narrow-band color filter with a wavelength of 650nm; the LED beads on the light strip have a wavelength of 650nm.

5. The protective window contamination detection device for laser welding equipment according to claim 1 or 2, characterized in that: The groove of the light strip is U-shaped with the opening facing upwards. The height direction of the groove is parallel to the axis of the lens mounting ring. Light-emitting holes are distributed around the periphery of the groove to position the LED beads on the light strip.

6. The protective window contamination detection device for laser welding equipment according to claim 5, characterized in that: Below the field lens connecting ring and above the lamp strip groove, there is a flange on the inner side wall of the lens mounting ring, which is arranged along the periphery. The protective window lens is sandwiched between the flange and the clamping ring. The clamping ring is threadedly connected to the lower end of the lens mounting ring to clamp the protective window lens. The periphery of the protective window lens is attached to the outer side wall of the lamp strip groove. The center of the peripheral wall of the protective window lens is aligned with the center of the LED beads on the lamp strip. The light emitted by the LED beads on the lamp strip enters from the peripheral wall of the protective window lens.

7. The protective window contamination detection device for laser welding equipment according to claim 1 or 2, characterized in that: The upper end of the field lens connecting ring extends beyond the lens mounting ring and has a threaded outer wall for connecting the field lens. The lower end of the field lens connecting ring has screw mounting holes for connecting with the lens mounting ring. The outer peripheral wall of the lens mounting ring has spaced horizontal waist-shaped holes, which are fixed to the screw holes on the outer peripheral wall of the field lens connecting ring by half-thread screws. The relative position of the lens mounting ring and the field lens connecting ring can be adjusted by loosening the half-thread screws.

8. The protective window contamination detection device for laser welding equipment according to claim 1 or 2, characterized in that: The support wall includes a first mounting surface and a second mounting surface with an included angle of 120~160°. The outer wall of the lens mounting ring is mounted on the back end of the first mounting surface through a pad. The cover is adjustablely mounted on the back side of the second mounting surface. The light strip is annular, and the field lens connecting ring, lens mounting ring, light strip and clamping ring are all concentrically arranged.

9. A method for detecting contamination on a protective window lens of a laser welding equipment, comprising using the contamination detection device for a protective window of a laser welding equipment as described in any one of claims 1-8, characterized in that: The field lens connecting ring and the protective window lens were not pre-installed on the lens mounting ring; include: 1) Install the upper end of the field lens connecting ring 2 onto the field lens of the laser welding equipment by threading. After the lens mounting ring is placed on the field lens connecting ring, adjust the angle of the field lens connecting ring relative to the lens mounting ring and lock it with a half-thread screw. Then install the cleaned or brand-new protective window lens onto the lens mounting ring. 2) When the light strip is turned on, the light will be reflected multiple times inside the protective window lens and captured by the imaging component as the reference imaging data; 3) During the laser welding equipment processing operation, the light strip is turned on at regular intervals. The light is used to detect dirt on the surface of the protective window lens by reflecting it multiple times inside the lens. The imaging component is used to take pictures as the operation imaging data. 4) Compare and analyze the running imaging data with the reference imaging data. The reference imaging data is used as background noise. Calculate the pixel grayscale value of the image after removing the background noise from the running imaging data. When the grayscale value and the contaminated area reach the preset value, determine the location and extent of contamination of the protective window lens. Clean or replace the protective window lens by removing and installing the fastening ring. Otherwise, if the grayscale value and the contaminated area do not reach the preset value, continue to use the protective window lens.

10. The method for detecting contamination of protective window lenses for laser welding equipment according to claim 9, characterized in that: Step 4) Employ an N×N grid regionalization strategy: For each sub-region, based on the gray-scale anomaly characteristics typically exhibited by pollutants, set differentiated gray-scale threshold ranges and soiling area values ​​to achieve accurate extraction of pollutants from different regions.

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