A method for full circumference laser processing on a key of an article sprayed with UV paint

Abstract

The present application relates to laser full circumference processing technical field, specifically, it relates to a kind of full circumference laser processing method on the product key of UV coating spraying.It includes the three-dimensional model of the product key of import product key, determines the full circumference trajectory and initial processing point of laser processing;Use mechanical arm fixedly bear product key, and use camera to carry out position check to product key;Mechanical arm drives product key to move and rotate.The present application makes product key move along full circumference trajectory continuously by mechanical arm, makes laser complete engraving once, and laser always keeps perpendicular with the position of product key being engraved during processing, realizes integrated annular laser processing zone without interruption, without splicing, fundamentally eliminates the joint misplacement, discontinuity or overlapping defect caused by multiple error superposition of segmented processing, guarantees the continuity and uniformity of laser processing area in circumferential direction, so as to ensure the continuity and sealing of functional layer.

Description

Technical Field

[0001] This invention relates to the field of laser full-circumference processing technology, and more specifically, to a method for performing full-circumference laser processing on buttons of products coated with UV paint. Background Technology

[0002] In the field of laser processing, when performing 360° continuous laser marking or processing on the annular circumferential surface of a workpiece (such as the outer circumferential surface of a cylindrical part), if the equipment does not have a full-circumferential multi-axis linkage or rotating beam scanning scheme, a segmented laser processing strategy is usually adopted. The basic idea of ​​this strategy is to artificially divide the complete annular area to be processed on the workpiece into at least four independent sub-regions (i.e., processing surfaces) along the circumferential direction. By adjusting the laser head posture or the workpiece clamping angle, the surface to be processed in each sub-region is made as perpendicular as possible to the incident laser beam at the moment of processing, so as to ensure the consistency of energy density and depth of focus in each region. After the laser operation is completed in each sub-region in sequence, the processing marks are joined end to end in the circumferential direction, and theoretically should be pieced together to form a complete annular laser processing band, thereby achieving an equivalent 360° full-coverage processing effect.

[0003] However, the aforementioned segmented processing method reveals significant technical defects in practical applications, particularly at the joints between segments. Since each segmented processing relies on an independent positioning datum and coordinate system transformation, factors such as workpiece clamping errors, rotational indexing errors, laser head repetitive positioning errors, and thermal deformation accumulate, causing the actual spatial position of adjacent partition boundaries to deviate from the theoretical trajectory. The direct consequences are that the laser markings between segments cannot be precisely aligned, resulting in obvious misalignment, discontinuity, or overlap at the joint lines. The resulting annular laser pattern is not a continuous, uniform, complete ring on the circumference, but rather exhibits localized distortion, breaks, or step-like deformation. This defect not only severely damages the appearance consistency of the laser-processed area but may also affect the continuity and sealing of functional layers (such as laser welding, quenching, or marking applications), making it difficult for segmented processing to meet the quality requirements of high-precision annular laser operations. This limits the reliable application of this process in scenarios where a full-circumference laser solution is unavailable.

[0004] Meanwhile, due to the inherent characteristics of UV coatings, they exhibit a strong reflective effect on light. This is due to various ambient light sources, including fluorescent or LED workstation lights, natural light entering through windows, light radiation from adjacent equipment, and even reflected light fluctuations caused by personnel movement. These ambient lights are characterized by random intensity, broad spectrum, variable direction of incidence, and instability over time. When these light sources are superimposed on active lighting sources and enter the camera sensor, they produce various negative effects. For traditional image detection systems employing algorithms such as fixed thresholds and template matching, ambient light interference often becomes a major cause of false positives and false negatives. The system cannot distinguish between genuine defects in the engraved text and false differences caused by changes in lighting, leading to decreased detection repeatability, increased false alarm rates, and even requiring frequent manual intervention to recalibrate the light source and camera parameters. This problem is particularly prominent when inspecting highly reflective, curved, and low-contrast workpieces, making it impossible to clearly obtain the engraving trajectory on the product's buttons after capturing the engraved image. Summary of the Invention

[0005] The purpose of this invention is to provide a method for performing full-circumference laser processing on buttons of products coated with UV paint, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, a method for performing full-circumference laser processing on buttons of products coated with UV paint is provided, comprising the following steps: S1. Import the 3D model of the product button, determine the full circumference trajectory of laser processing, and determine the initial processing point of laser processing of the product button on the full circumference trajectory; S2. Use a robotic arm to fix the product button, and use a camera to check the position of the product button. After the check is completed, the robotic arm will move the product button to the processing point. S3. During the laser engraving process of the laser machine on the product button, the robotic arm drives the product button to move and rotate, so that the laser can engrave the entire circumference trajectory in one go. During the laser engraving process, the laser is perpendicular to the position to be engraved on the product button, ensuring that the entire circumference trajectory is uninterrupted and spliced ​​in the circumferential direction, forming a continuous and uniform annular laser processing band. S4. After the button processing is completed, use a high-pressure jet nozzle to blow air onto the laser-processed area of ​​the button and use a suction fan to absorb the material engraved by the laser. S5. After the air blowing is completed, the robotic arm moves the product button to the image detection area, where a camera is used to detect the trajectory curve of the product button surface processing.

[0007] As a further improvement to this technical solution, S1 specifically includes: S1.1 Import the 3D model of the product buttons into 3D software, and use the 3D software to draw the trajectory curve of laser processing on the 3D model of the product; S1.2 Select a point on the straight part of the laser processing trajectory curve on the 3D model of the button in the product as the initial processing point; S1.3 Program the movement trajectory of the robotic arm, determine the laser position and direction, and determine the gripping point of the product button, the initial processing point of the product button and the unloading point, the movement trajectory of the product button to the lower side of the laser engraving machine, and determine the starting position and processing direction of the laser trajectory curve processing. S1.4 In the 3D software, after the full circumference trajectory of laser processing is determined, the standard laser engraving full circumference trajectory on the product button is determined based on the positional relationship between the straight edge on the fixture and the full circumference trajectory on the product button. The spatial posture of the product button when the robotic arm drives it to move continuously along the full circumference trajectory is simulated in the 3D software, and the theoretical coordinates and normal vectors of each point on the full circumference trajectory are recorded. As a further improvement to this technical solution, S2 specifically includes: S2.1 A special fixture for carrying the product buttons is installed on the robotic arm, and the product buttons are installed on the special fixture; S2.2 Use a camera to photograph the button of the product fixed on the fixture, and use the projection reference system of the button edge on the fixture as the comparison reference. Then measure the distance, offset and parallelism of the button edge line relative to the comparison reference to determine the actual position of the button of the product. S2.3 When the actual position of the button in the work-in-process does not meet the set requirements, an alarm is issued and the robotic arm is not started. After the staff reinstalls it in place, the position is checked again according to the sequence of S2.2, and the robotic arm is started after it is confirmed to be qualified. S2.4 The robotic arm moves and rotates the product button, moving it to the laser processing position and aligning the initial processing point of the product button with the laser processing position. During the movement of the product button, the robotic arm adjusts the position of the product button. S2.5 After the robotic arm moves the product button to the laser processing station and before the laser beam is emitted, the ambient light active suppression process is started, and a reference image is captured by a camera before laser processing. This reference image contains only the inherent reflection information of the workpiece surface under active lighting.

[0008] As a further improvement to this technical solution, the step of determining the actual position state of the button in S2.2 is as follows: First, create a model of the fixture and the correctly positioned button on the product, using the straight line on the fixture and the edge line between the button and the product as the comparison line segments: When confirming the actual position of the button on the product, Hikvision vision inspection software is used to select the target high-definition match from the image source obtained by taking pictures. In the target image, the straight line on the fixture and the edge line of the button on the product are detected by the relationship between the edge of the fixture and the brightness of the background. The two detected straight lines are then measured. Using the distance between two straight lines in the model diagram as a standard, the actual distance between the two straight lines is measured and compared with the distance between the two straight lines in the model diagram. If the distance exceeds the standard distance in the model diagram by 3%, it is considered to have a gap and poor positioning.

[0009] As a further improvement to this technical solution, the adjustment of the position state of the product button in S2.4 includes: Determine the optimal distance for laser processing and position the initial processing point at the optimal distance directly below the laser processing point. Simultaneously, adjust the position of the button on the product so that the plane on the button where the initial processing point is determined is perpendicular to the laser emitted by the laser machine.

[0010] As a further improvement to this technical solution, the active ambient light suppression process in S2.5 is as follows: First, turn off the white fluorescent lights and LED workstation lights around the workstation, and pull the light-shielding curtains on the equipment to block natural light and light radiation from adjacent equipment; then turn on the active compensation lighting source arranged coaxially with the laser processing. This reference image records the distribution characteristics of the active lighting component on the surface of the product button, which will be used as a reference base map for background subtraction in the subsequent image inspection stage.

[0011] As a further improvement to this technical solution, the specific steps of S5 are as follows: S5.1 The image detection area uses a strip of red light source to illuminate the button on the product, and the angle of the strip of red light source is adjusted so that the angle of the red light source is perpendicular to the position of the button on the product that needs to be illuminated. S5.2. Use a brown glass plate as a physical isolation window between the detection area and the ambient light to actively suppress the ambient light entering the image detection area; at the same time, perform pixel-by-pixel gray-level difference calculation with the reference image acquired in S2.5 to further eliminate the influence of residual ambient light fluctuations transmitted through the brown glass plate. S5.3 Use two cameras to capture images of the laser-processed trajectory to obtain images of the laser-processed trajectory. One camera captures the image of the special fixture and the laser engraving trajectory, and the other camera captures the image of the laser engraving trajectory and the edge of the button on the product. All images are processed using a background subtraction algorithm based on the reference image to remove the influence of ambient light. S5.4 Analyze the captured images to determine whether the laser processing trajectory is qualified, and issue corresponding signals based on whether it is qualified.

[0012] As a further improvement to this technical solution, the step of using the background subtraction algorithm of the reference image in S5.3 is as follows: After laser processing is completed, the measured image captured by the camera at the inspection station actually contains two parts of information: active illumination component and ambient light interference component. Based on the active illumination component that has been pre-recorded in the reference image collected in S2.5, the measured image and the reference image are subjected to pixel-by-pixel grayscale difference operation. The active illumination components are canceled out, and the difference result only retains the engraving trajectory information corresponding to the changes in surface state before and after laser processing.

[0013] As a further improvement to this technical solution, the step of analyzing the captured images in S5.4 is as follows: Based on the theoretical coordinates and normal vector of the full circumference trajectory recorded in S1.4, the actual positions of each sampling point are extracted along the entire full circumference trajectory in the measured image. According to the positional relationship between the detected straight line and the laser trajectory engraved on the product button and the straight line and the full circumference trajectory on the product button determined in the 3D software, the radial deviation and normal deviation of each point relative to the theoretical trajectory are calculated, and it is determined whether the deviation values ​​are within the set value range to preliminarily judge whether the laser effect meets the requirements. At the same time, the consistency of the trajectory line width and the uniformity of gray scale distribution are detected along the circumferential direction to determine whether there are defects such as local overheating, sudden changes in line width or uneven color depth caused by fluctuations in the movement speed or changes in posture of the robotic arm.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In this method of performing full-circumference laser processing on buttons of products coated with UV paint, a robotic arm drives the button to move continuously along the full-circumference trajectory, and a laser is used to perform a one-time complete engraving. During the processing, the laser always remains perpendicular to the engraved position of the button, realizing an uninterrupted and seamless integrated annular laser processing zone. This fundamentally eliminates the defects of misalignment, discontinuity or overlap caused by multiple superposition errors in segmented processing, ensuring the continuity and uniformity of the laser processing area in the circumferential direction, thereby ensuring the continuity and sealing of the functional layer.

[0015] 2. In the method of performing full-circumference laser processing on buttons of products coated with UV paint, an active suppression process is achieved by turning off the ambient light source, pulling the light-shielding curtain and acquiring the reference image before laser processing. Combined with the physical isolation of the detection area by the brown glass plate and the pixel-by-pixel gray-level difference calculation between the reference image and the measured image, dual suppression of ambient light is achieved. This makes the image detection system almost completely immune to ambient light, and completely solves the problems of decreased detection repeatability, increased false alarm rate and the need for frequent manual intervention to correct parameters caused by the randomness of ambient light intensity, wide spectrum and instability over time. This ensures that the system operates stably under different lighting conditions.

[0016] 3. In the method of performing full-circumference laser processing on buttons of products coated with UV paint, by using a strip red light source and optimizing the illumination angle, and taking advantage of the difference in red light absorption between the UV paint and the laser-modified area, the specular reflection is actively guided out of the field of view, leaving only diffuse reflection. This achieves glare-free, high-contrast imaging of the entire curved surface, solving the problems of image contrast loss on highly reflective curved workpieces and the system's inability to distinguish between real defects and false differences in illumination. Clear and stable detection images can be obtained without relying on complex image processing algorithms. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the overall steps of the present invention. Detailed Implementation

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

[0019] Example 1. Please refer to Example 1. Figure 1 As shown, the purpose of this embodiment is to provide a method for performing full-circumference laser processing on buttons of products coated with UV paint, including the following steps: S1. Import the 3D model of the product button, determine the full circumference trajectory of laser processing, and determine the initial processing point of laser processing of the product button on the full circumference trajectory; S1.1 Import the 3D model of the product buttons into 3D software, such as SolidWorks, and use the 3D software to draw the laser processing trajectory curve on the 3D model of the product. S1.2 Select a point on the straight part of the laser processing trajectory curve on the 3D model of the button in the product as the initial processing point (or use a special location specified by the customer as the initial processing point). S1.3 Program the movement trajectory of the robotic arm, determine the laser position and direction, and determine the gripping point of the product button, the initial processing point of the product button, and the unloading point. Determine the movement trajectory of the product button to the lower side of the laser engraving machine, and determine the starting position and processing direction of the laser trajectory curve processing.

[0020] Before adjusting the button positions on the product, corresponding commands can be controlled on the software controlling the robotic arm. By adjusting the joint coordinates of the robotic arm and moving the coordinate values ​​of each joint in real time, the product can be moved to the designated position.

[0021] To ensure that the laser is perpendicular to the plane where the points engraved on the product buttons are located, the direction (x, y, z axis) of each point on the laser processing trajectory curve is marked when drawing the curve in the software. This direction is used to match the laser direction later to achieve the required angle between the laser and the processing surface.

[0022] Meanwhile, the laser focal length in laser processing is fixed. The robotic arm moves and rotates the buttons on the product, keeping the laser focus on the surface of the buttons to be laser-engraved.

[0023] S1.4 In the 3D software, after the full circumference trajectory of laser processing is determined, the standard laser engraving full circumference trajectory on the product button is determined based on the positional relationship between the straight edge on the fixture and the full circumference trajectory on the product button. At the same time, the distance between the product and the edge of the button is obtained. In the 3D software, the spatial posture of the product button is simulated when the robotic arm drives it to move continuously along the full circumference trajectory. The theoretical coordinates and normal vectors of each point on the full circumference trajectory are recorded as the benchmark reference for subsequent trajectory consistency detection.

[0024] S2. Use a robotic arm to fix the product button, and use a camera to check the position of the product button. After the check is completed, the robotic arm will move the product button to the processing point. S2.1 A special fixture for carrying the product buttons is installed on the robotic arm, and the product buttons are installed on the special fixture; S2.2 Use a camera to photograph the button of the product fixed on the fixture, and use the projection reference system of the button edge on the fixture as the comparison reference. Then measure the distance, offset and parallelism of the button edge line relative to the comparison reference to determine the actual position of the button of the product. First, a model diagram of the fixture and the correctly positioned button of the product is created. Using the straight line on the fixture and the edge line between the button and the product as the comparison line segment, when confirming the actual position of the button, Hikvision vision inspection software is used to select the target high-definition matching from the image source obtained by photography. In the target image, the straight line on the fixture and the edge line of the button are detected by the relationship between the edge of the fixture and the brightness of the background. The two detected straight lines are measured. The distance between the two straight lines in the model diagram is used as the standard. The distance between the two measured straight lines is compared with the distance between the two straight lines in the model diagram. If the distance exceeds 3% of the standard distance in the model diagram, there is a gap and the position is not good. This determines whether the position of the button fixed on the fixture is correct.

[0025] S2.3 When the actual position of the button in the work-in-process does not meet the set requirements, an alarm is issued and the robotic arm is not started. After the staff reinstalls it in place, the position is checked again according to the sequence of S2.2, and the robotic arm is started after it is confirmed to be qualified. S2.4 The robotic arm moves and rotates the product button, moving it to the laser processing position and aligning the initial processing point of the product button with the laser processing position. During the movement of the product button, the robotic arm adjusts the position of the product button. The status adjustment includes: Determine the optimal distance for laser processing and position the initial processing point at the optimal distance directly below the laser processing point. At the same time, adjust the position of the button on the product so that the plane on the button where the initial processing point is determined is perpendicular to the laser emitted by the laser machine. S2.5 After the robotic arm moves the product button to the laser processing station and before the laser beam is emitted, the ambient light active suppression process is started, and a reference image is captured by a camera before laser processing. This reference image contains only the inherent reflection information of the workpiece surface under active illumination.

[0026] The ambient light active suppression process is as follows: First, turn off the white fluorescent lights and LED workstation lights around the workstation, and pull the light-shielding curtains on the equipment to block natural light and light radiation from adjacent equipment; then turn on the active compensation lighting source arranged coaxially with the laser processing. This reference image records the distribution characteristics of the active lighting component on the surface of the product button, which will be used as a reference base map for background subtraction in the subsequent image detection stage to eliminate the active lighting component and ambient light interference component in the measured image.

[0027] S3. During the laser engraving process of the laser machine on the product button, the robotic arm drives the product button to move and rotate, so that the laser can engrave the entire circumference trajectory in one go. During the laser engraving process, the laser is perpendicular to the position to be engraved on the product button, ensuring that the entire circumference trajectory is uninterrupted and spliced ​​in the circumferential direction, forming a continuous and uniform annular laser processing band. S4. After the button processing is completed, use a high-pressure jet nozzle to blow air onto the laser-processed area of ​​the button and use a suction fan to absorb the material engraved by the laser.

[0028] S5. After the air blowing is completed, the robotic arm moves the product button to the image detection area, where a camera is used to detect the trajectory curve of the product button surface processing.

[0029] S5.1 The image detection area uses a strip of red light source to illuminate the button on the product, and the angle of the strip of red light source is adjusted so that the angle of the red light source is perpendicular to the position of the button on the product that needs to be illuminated. By using a strip of red light source and illuminating at a specific angle, the specular reflection is actively guided out of the field of view, retaining only diffuse reflection, thus achieving glare-free imaging across the entire curved surface. The use of a red light source instead of a white light source is because the silver-gray paint on the product surface is prone to reflection under white light. Furthermore, by utilizing the difference in red light absorption between the UV coating and the laser-modified area, the image contrast is significantly improved without the need for special image processing.

[0030] S5.2. A brown glass plate is used as a physical isolation window between the detection area and the ambient light to actively suppress the ambient light entering the image detection area. The brown glass plate can filter out white light. At the same time, it is used in conjunction with the reference image acquired in S2.5 to perform pixel-by-pixel gray-level difference calculation to further eliminate the influence of residual ambient light fluctuations through the brown glass plate. This allows the inspection area to be in a relatively stable lighting environment, so as to avoid the problem of excessive changes in the brightness and darkness of the product button detection surface due to changes in weather over time and excessive light outside the device. This makes the detection system almost completely immune to ambient light.

[0031] By combining the strategies of S2.5 and S5.2, the interference of random ambient light fluctuations on image detection, as described in the background technology, is completely eliminated from two dimensions: "actively shielding the light source" and "algorithm-based background subtraction." Furthermore, by combining customized spectral illumination and active ambient light suppression, this method addresses two major challenges in laser text detection using curved UV coatings: contrast loss due to strong reflections and positioning drift caused by geometric uncertainties on curved surfaces. This method does not rely on complex and expensive 3D sensors or deep learning hardware; it achieves high-precision online full inspection solely through ingenious optomechanical design and measurement strategies.

[0032] S5.3 Use two cameras to capture images of the laser-processed trajectory to obtain images of the laser-processed trajectory. One camera captures the image of the special fixture and the laser engraving trajectory, and the other camera captures the image of the laser engraving trajectory and the edge of the button on the product. All images are processed using a background subtraction algorithm based on the reference image to remove the influence of ambient light. The steps of the background subtraction algorithm using the reference image are as follows: After the laser processing is completed, the actual measured image captured by the camera at the inspection station contains two parts of information: active illumination component and ambient light interference component. Based on the active illumination component that has been pre-recorded in the reference image collected in S2.5, the measured image and the reference image are subjected to pixel-by-pixel gray-level difference operation (i.e., the gray-level values ​​at the same position are subtracted). The active illumination components are canceled out, and only the engraving trajectory information corresponding to the surface state changes before and after laser processing is retained in the difference result.

[0033] Meanwhile, to overcome the slight positional shifts caused by the repetitive positioning when the robotic arm moves the product buttons from the processing station to the inspection station, affine registration based on straight lines on the fixture is performed on the reference image and the measured image before the differential calculation to eliminate translation and rotation deviations. For pixels in the differential image whose grayscale value is less than a set threshold (which is pre-calibrated based on the intensity of the active illumination source and the camera noise level), their grayscale value is set to zero to suppress residual fluctuations caused by sensor noise. Through the above methods, ambient light interference in the measured image is effectively eliminated, retaining only the true information of the laser engraving trajectory, making the inspection system completely immune to ambient light fluctuations.

[0034] S5.4 Analyze the captured images to determine whether the laser processing trajectory is qualified, and issue corresponding signals based on whether it is qualified.

[0035] When analyzing the captured images, the theoretical coordinates and normal vector of the full-circumference trajectory recorded in S1.4 are used as a reference. The actual positions of each sampling point are extracted along the entire full-circumference trajectory in the measured image. Based on the positional relationship between the detected straight lines and the laser trajectory engraved on the product button and the straight lines and full-circumference trajectory determined in the 3D software, the radial and normal deviations of each point relative to the theoretical trajectory are calculated, and it is determined whether the deviation values ​​are within the set range to preliminarily judge whether the laser effect meets the requirements. At the same time, the consistency of the trajectory linewidth and the uniformity of grayscale distribution are detected along the circumferential direction to determine whether there are defects such as local overheating, abrupt changes in linewidth, or uneven color depth caused by fluctuations in the robotic arm's movement speed or posture changes. If the deviation or uniformity index of any sampling point exceeds the set threshold, the trajectory is judged to be unqualified.

[0036] Meanwhile, another camera in the image detection area compares and calculates the distance between the engraving trajectory and the edge of the button to determine whether the laser position meets the requirements, further improving the accuracy of laser engraving trajectory detection.

[0037] The good product output alarm light is green (OK signal), and the bad product output alarm light is red (NG signal) and a buzzer sounds. At this time, it needs to be cleared by pressing the release button, otherwise it will keep beeping to ensure that the unqualified products flow to the next process and to ensure the good product rate of the finished products leaving the factory.

[0038] When a defective product is found, the system analyzes the source of the deviation based on the trajectory deviation data recorded in S5.4 (including radial deviation, normal deviation, line width variation, and grayscale distribution). If the deviation is systematically distributed in one direction, it is determined to be a zero-point offset of the robotic arm or a coordinate system calibration error, and the kinematic parameters of the robotic arm are corrected accordingly. If the deviation fluctuates periodically, it is determined to be an unstable interpolation of the robotic arm's movement speed or posture, and the speed curve and posture smoothing parameters in the robotic arm trajectory planning are optimized accordingly. If the deviation only occurs in a specific angle range, it is determined to be a slight looseness in the workpiece clamping or wear on the fixture positioning surface within that range, and the fixture is prompted for manual inspection. After correction, the updated parameters are applied to the processing of subsequent workpieces. Through continuous closed-loop optimization, the full-circumference trajectory accuracy of subsequent laser engraving is continuously improved, ensuring the accuracy and consistency of laser engraving on the product buttons.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for performing full-circumference laser processing on buttons of products coated with UV paint, characterized in that: Includes the following steps: S1. Import the 3D model of the product button, determine the full circumference trajectory of laser processing, and determine the initial processing point of laser processing of the product button on the full circumference trajectory; S2. Use a robotic arm to fix the product button, and use a camera to check the position of the product button. After the check is completed, the robotic arm will move the product button to the processing point. S3. During the laser engraving process of the laser machine on the product button, the robotic arm drives the product button to move and rotate, so that the laser can engrave the entire circumference trajectory in one go. During the laser engraving process, the laser is perpendicular to the position to be engraved on the product button, ensuring that the entire circumference trajectory is uninterrupted and spliced ​​in the circumferential direction, forming a continuous and uniform annular laser processing band. S4. After the button processing is completed, use a high-pressure jet nozzle to blow air onto the laser-processed area of ​​the button and use a suction fan to absorb the material engraved by the laser. S5. After the air blowing is completed, the robotic arm moves the product button to the image detection area, where a camera is used to detect the trajectory curve of the product button surface processing.

2. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 1, characterized in that: S1 specifically includes: S1.1 Import the 3D model of the product buttons into 3D software, and use the 3D software to draw the trajectory curve of laser processing on the 3D model of the product; S1.2 Select a point on the straight part of the laser processing trajectory curve on the 3D model of the button in the product as the initial processing point; S1.3 Program the movement trajectory of the robotic arm, determine the laser position and direction, and determine the gripping point of the product button, the initial processing point of the product button and the unloading point, the movement trajectory of the product button to the lower side of the laser engraving machine, and determine the starting position and processing direction of the laser trajectory curve processing. S1.4 In the 3D software, after the full circumference trajectory of laser processing is determined, the standard laser engraving full circumference trajectory on the product button is determined based on the positional relationship between the straight edge on the fixture and the full circumference trajectory on the product button. The spatial posture of the product button when the robotic arm drives it to move continuously along the full circumference trajectory is simulated in the 3D software, and the theoretical coordinates and normal vectors of each point on the full circumference trajectory are recorded.

3. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 2, characterized in that: S2 specifically includes: S2.1 A special fixture for carrying the product buttons is installed on the robotic arm, and the product buttons are installed on the special fixture; S2.2 Use a camera to photograph the button of the product fixed on the fixture, and use the projection reference system of the button edge on the fixture as the comparison reference. Then measure the distance, offset and parallelism of the button edge line relative to the comparison reference to determine the actual position of the button of the product. S2.3 When the actual position of the button in the work-in-process does not meet the set requirements, an alarm is issued and the robotic arm is not started. After the staff reinstalls it in place, the position is checked again according to the sequence of S2.2, and the robotic arm is started after it is confirmed to be qualified. S2.4 The robotic arm moves and rotates the product button, moving it to the laser processing position and aligning the initial processing point of the product button with the laser processing position. During the movement of the product button, the robotic arm adjusts the position of the product button. S2.5 After the robotic arm moves the product button to the laser processing station and before the laser beam is emitted, the ambient light active suppression process is started, and a reference image is captured by a camera before laser processing. This reference image contains only the inherent reflection information of the workpiece surface under active lighting.

4. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 3, characterized in that: The step in S2.2 to determine the actual position state of the button on the product is as follows: First, create a model of the fixture and the correctly positioned button on the product, using the straight line on the fixture and the edge line between the button and the product as the comparison line segments: When confirming the actual position of the button on the product, Hikvision vision inspection software is used to select the target high-definition match from the image source obtained by taking pictures. In the target image, the straight line on the fixture and the edge line of the button on the product are detected by the relationship between the edge of the fixture and the brightness of the background. The two detected straight lines are then measured. Using the distance between two straight lines in the model diagram as a standard, the actual distance between the two straight lines is measured and compared with the distance between the two straight lines in the model diagram. If the distance exceeds the standard distance in the model diagram by 3%, it is considered to have a gap and poor positioning.

5. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 3, characterized in that: The adjustment of the position state of the product button in S2.4 includes: Determine the optimal distance for laser processing and position the initial processing point at the optimal distance directly below the laser processing point. Simultaneously, adjust the position of the button on the product so that the plane on the button where the initial processing point is determined is perpendicular to the laser emitted by the laser machine.

6. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 3, characterized in that: The active ambient light suppression process in S2.5 is as follows: First, turn off the white fluorescent lights and LED workstation lights around the workstation, and pull the light-shielding curtains on the equipment to block natural light and light radiation from adjacent equipment; then turn on the active compensation lighting source arranged coaxially with the laser processing. This reference image records the distribution characteristics of the active lighting component on the surface of the product button, which will be used as a reference base map for background subtraction in the subsequent image inspection stage.

7. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 1, characterized in that: The specific steps of S5 are as follows: S5.1 The image detection area uses a strip of red light source to illuminate the button on the product, and the angle of the strip of red light source is adjusted so that the angle of the red light source is perpendicular to the position of the button on the product that needs to be illuminated. S5.

2. Use a brown glass plate as a physical isolation window between the detection area and the ambient light to actively suppress the ambient light entering the image detection area; at the same time, perform pixel-by-pixel gray-level difference calculation with the reference image acquired in S2.5 to further eliminate the influence of residual ambient light fluctuations transmitted through the brown glass plate. S5.3 Use two cameras to capture images of the laser-processed trajectory to obtain images of the laser-processed trajectory. One camera captures the image of the special fixture and the laser engraving trajectory, and the other camera captures the image of the laser engraving trajectory and the edge of the button on the product. All images are processed using a background subtraction algorithm based on the reference image to remove the influence of ambient light. S5.4 Analyze the captured images to determine whether the laser processing trajectory is qualified, and issue corresponding signals based on whether it is qualified.

8. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 7, characterized in that: The steps of the background subtraction algorithm using the reference image in S5.3 are as follows: After laser processing is completed, the measured image captured by the camera at the inspection station actually contains two parts of information: active illumination component and ambient light interference component. Based on the active illumination component that has been pre-recorded in the reference image collected in S2.5, the measured image and the reference image are subjected to pixel-by-pixel grayscale difference operation. The active illumination components are canceled out, and the difference result only retains the engraving trajectory information corresponding to the changes in surface state before and after laser processing.

9. The method for performing full-circumference laser processing on buttons of products coated with UV paint according to claim 8, characterized in that: The steps for analyzing the captured images in S5.4 are as follows: Based on the theoretical coordinates and normal vector of the full circumference trajectory recorded in S1.4, the actual positions of each sampling point are extracted along the entire full circumference trajectory in the measured image. According to the positional relationship between the detected straight line and the laser trajectory engraved on the product button and the straight line and the full circumference trajectory on the product button determined in the 3D software, the radial deviation and normal deviation of each point relative to the theoretical trajectory are calculated, and it is determined whether the deviation values ​​are within the set value range to preliminarily judge whether the laser effect meets the requirements. At the same time, the consistency of the trajectory line width and the uniformity of gray scale distribution are detected along the circumferential direction to determine whether there are defects such as local overheating, sudden changes in line width or uneven color depth caused by fluctuations in the movement speed or changes in posture of the robotic arm.

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