A method and system for automatically detecting surface defects of a paint coating

Abstract

This invention relates to an automatic detection method and system for coating surface defects, belonging to the field of coating defect detection technology. The method includes: acquiring coating information in response to a start signal; selecting a detection laser type based on the coating information; controlling a laser irradiation device to irradiate at a preset laser starting position according to the detection laser type, and decomposing the coating information to obtain a standard received intensity; acquiring the actual received intensity and the corresponding actual received area; calculating the intensity difference between the actual received intensity and the standard received intensity; when the intensity difference is greater than a preset error intensity, obtaining the actual irradiated area based on the actual received area, and defining this actual irradiated area as a coating defect area; generating a recoating plan based on the coating defect area, and outputting the recoating plan. This invention improves the accuracy of coating surface defect detection.

Description

Technical Field

[0001] This invention relates to the field of coating defect detection technology, and in particular to an automatic detection method and system for surface defects in paint coatings. Background Technology

[0002] Coatings are a widely used material in modern industrial production and daily life. They are mainly used for the decoration and protection of object surfaces. The application fields of coatings include automobile manufacturing, building decoration, electronic equipment, furniture, etc. The quality of coatings directly affects the appearance and function of products.

[0003] In related technologies, image detection is often used to detect defects in coatings. This involves using an industrial camera to collect images of the coating surface, preprocessing the collected images, and then using image processing algorithms to extract feature information from the images. Based on the extracted feature information, it is determined whether there are defects on the coating surface, and the identified defect areas are located.

[0004] Regarding the aforementioned technologies, defect detection methods based on images are easily affected by factors such as lighting, coating reflection, and surface texture, resulting in inaccurate detection accuracy and a tendency to make misjudgments. Summary of the Invention

[0005] To improve the accuracy of detecting defects on coating surfaces, this invention provides an automatic detection method and system for coating surface defects.

[0006] In a first aspect, the present invention provides an automatic detection method for surface defects in coatings, employing the following technical solution: An automatic detection method for surface defects in paint coatings includes: Step 1: In response to the start signal, acquire coating information; Step 2: Select the type of detection laser based on the coating information; Step 3: Control the laser irradiation device to irradiate at the preset laser starting position according to the type of laser being detected, and disassemble the coating information to obtain the standard receiving intensity; Step 4: Obtain the actual received signal strength and the corresponding actual received area; Step 5: Calculate the intensity difference based on the actual received intensity and the standard received intensity; Step 6: When the intensity difference is greater than the preset error intensity, the actual irradiation area will be obtained based on the actual receiving area, and the actual irradiation area will be defined as the coating defect area. Step 7: Generate a recoating plan based on the defective areas of the coating, and output the recoating plan.

[0007] By adopting the above technical solution, the difference in laser reflection intensity is used to detect coating defects. Compared with traditional image detection methods, it can effectively reduce the influence of interference factors such as illumination, reflection, and surface texture. By comparing the standard received intensity with the actual received intensity, it can accurately identify whether there are defects such as missing coating in the coating, thus improving the accuracy and stability of defect detection.

[0008] Optionally, a control method is also included when the strength difference is less than the error strength, the method comprising: Step 60: When the strength difference is less than the error strength, take the absolute value of the strength difference to obtain the absolute difference; Step 61: When the absolute difference is greater than the error intensity, obtain the area coating image based on the actual irradiated area; Step 62: Analyze the regional coating image to obtain the coating shape; Step 63: Analyze the abnormal reflection path based on the coating shape and the laser starting position; Step 64: Obtain the abnormal receiving area based on the actual irradiation area and the abnormal reflection path, and define the abnormal receiving area as the normal area.

[0009] By adopting the above technical solution, in the case of laser reflection path deviation caused by changes in coating surface shape, by combining image analysis of coating shape and reflection path, it is possible to distinguish between reflection anomalies and actual defects, avoid misjudgments caused by changes in surface morphology and angle, and further improve the reliability of detection results.

[0010] Optionally, it also includes a method for determining whether an abnormal reception area is truly a normal area, the method comprising: Step 640: Obtain the illumination angle and illumination height, and obtain the abnormal illumination area based on the abnormal reception area; Step 641: Obtain the actual irradiation location and the abnormal irradiation location based on the actual irradiation area and the abnormal irradiation area, and obtain the relative path based on the actual irradiation location and the abnormal irradiation location. Step 642: Calculate the midpoint based on the actual irradiation position and the abnormal irradiation position, and obtain the vertical path based on the midpoint and the relative path; Step 643: Obtain the verification laser position based on the midpoint, illumination angle, illumination height, and vertical path; Step 644: Control the laser irradiation device to move to the verification laser position and irradiate along a vertical path, and obtain the verification laser intensity corresponding to the abnormal irradiation area; Step 645: Calculate the absolute verification intensity difference based on the verification laser intensity and the standard received intensity; Step 646: When the absolute check strength difference is less than the error strength, the abnormal reception area is defined as the normal area; Step 647: When the absolute verification strength difference is greater than the error strength, the abnormal receiving area is defined as the coating defect area.

[0011] By adopting the above technical solution and adding a step of verifying laser irradiation, areas suspected of abnormal reflection are verified a second time, further eliminating misjudgments caused by abnormal reflection paths, realizing the verification of coating areas, and ensuring that the defect judgment results are true and valid.

[0012] Optionally, it also includes a method for controlling the laser irradiation device to move to the calibration laser position, the method comprising: Step 6440: Obtain the movement path based on the laser's starting position and the verified laser position; Step 6441: Obtain the path image based on the movement path; Step 6442: Identify the path image to obtain path obstacle features; Step 6443: When there are no obstacles on the path, control the laser irradiation device to move to the verification laser position according to the moving path and irradiate according to the vertical path; Step 6444: When path obstacle features exist, obtain the mirror verification position based on the verification laser position and relative path, and control the laser irradiation device to move to the mirror verification position to irradiate according to the vertical path.

[0013] By adopting the above technical solution, obstacles are identified and avoided in the path during the movement of the laser device, ensuring that the verification process can be executed smoothly, avoiding equipment interference from affecting the detection process, and improving the safety and continuity of system operation.

[0014] Optional, also includes: Step 8: Obtain the coating defect area number and detection path; Step 9: Obtain the adjacent defect area number based on the coating defect area number and the detection path, and search for the adjacent receiving intensity corresponding to the adjacent defect area number from the preset area information database; Step 10: When the actual received intensity is the same as the adjacent received intensity, obtain the current laser device number and the backup laser device number; Step 11: When a backup laser device number exists, replace the laser irradiation device corresponding to the backup laser device number with the laser irradiation device corresponding to the current laser device number.

[0015] By adopting the above technical solution, when the detection intensity of adjacent areas is consistent and both show abnormalities, it can be determined that the problem may be due to an abnormality in the laser device itself rather than a coating defect. By switching to a backup laser device, interference caused by equipment failure can be eliminated, ensuring the accuracy of the detection results.

[0016] Optional, also includes: Step 12: When the backup laser device number does not exist, obtain the adjacent defect area corresponding to the adjacent defect area number; Step 13: Obtain the correction length based on adjacent defect areas and the detection path; Step 14: Obtain the correction position based on the correction length and the laser starting position, and control the laser irradiation device to irradiate at the correction position to obtain the corrected receiving intensity; Step 15: Calculate the absolute correction difference based on the corrected received strength; Step 16: When the absolute correction difference is less than the error intensity, define the coating defect area corresponding to the coating defect area number as a normal area.

[0017] By adopting the above technical solution, in the absence of a backup device, the device can be re-illuminated and verified by correcting the position, which further reduces misjudgments caused by problems with the device itself and enables the reconfirmation of defective areas, thereby reducing the possibility of misjudgments.

[0018] Optionally, methods for generating recoating schemes based on coating defect areas include: Step 70: Obtain the shape and area of ​​the defect area based on the coating defect area; Step 71: Obtain the recoating diameter, and generate a recoating path based on the recoating diameter, the shape of the defect area, and the area of ​​the defect area; Step 72: Generate a recoating plan based on the recoating path and coating information.

[0019] By adopting the above technical solution, the corresponding repair path and repair scheme can be automatically generated according to the actual shape and area of ​​the defect, which can achieve precise repair of coating defects, improve the efficiency and quality of repair, and make the effect of the repaired coating closer to the standard requirements.

[0020] Optionally, methods for generating a recoating path based on the recoating diameter, the shape of the defect area, and the area of ​​the defect area include: Step 710: Obtain the minimum width based on the shape and area of ​​the defect region; Step 711: Determine the maximum number of recoating passes based on the minimum width and recoating diameter; Step 712: Calculate the total recoating width based on the number of recoating applications and the recoating diameter, and calculate the missing width based on the total recoating width and the minimum width; Step 713: Generate a full-coat path based on the maximum number of touch-up coats and the touch-up diameter, generate a partial-coat path based on the full-coat path and the missing width, and form a touch-up path based on the full-coat path and the partial-coat path.

[0021] By adopting the above technical solution, the recoating path of the defect area is calculated based on the recoating diameter. This fully considers the shape and size of the defect area, rationally plans the number of recoating operations and the final path, makes the recoating path more reasonable, further improves the accuracy and efficiency of recoating, and ensures that the defect area can be fully covered during the recoating process.

[0022] Optionally, methods for obtaining the actual received strength include: Step 40: Obtain the current received signal strength; Step 41: If the current received strength falls within the preset normal strength range, define the current received strength as the actual received strength and input it; Step 42: If the current received strength does not fall within the normal strength range, output an abnormal strength signal.

[0023] By adopting the above technical solution, abnormal intensity can be detected in a timely manner, which facilitates timely handling by operators, avoids affecting the test results due to abnormal intensity, and ensures the stability and reliability of the test process.

[0024] Secondly, the present invention provides an automatic detection system for surface defects in coatings, employing the following technical solution: An automatic detection system for surface defects in paint coatings, comprising: The acquisition module is used to acquire coating information, actual received intensity, and the corresponding actual received area. A memory for storing a program for an automatic detection method for surface defects of a coating as described above; The processor loads and executes programs from memory.

[0025] By adopting the above technical solution, relevant information is collected by the acquisition module, the detection method program is stored in the memory, and the program is executed by the processor, thereby realizing automated detection of coating defects and improving the accuracy and stability of defect detection.

[0026] In summary, the present invention has at least one of the following beneficial technical effects: Using laser reflection intensity detection instead of pure image detection can effectively reduce the interference of external factors such as illumination, coating reflection, and surface texture on the detection results, thereby improving the accuracy and reliability of the detection. By analyzing abnormal reflection paths and employing multiple verification mechanisms, the reflection shift caused by changes in surface morphology can be effectively distinguished from actual coating defects, thereby reducing the likelihood of misjudgment. Attached Figure Description

[0027] Figure 1 This is a flowchart of an automatic detection method for surface defects of a coating in this application. Figure 2This is a schematic diagram of the abnormal reflection path in an embodiment of this application; Figure 3 This is a schematic diagram of the repainting path in an embodiment of this application. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0029] This invention discloses an automatic detection method for surface defects in coatings. (Refer to...) Figure 1 An automatic detection method for surface defects in paint coatings includes: Step 1: In response to the start signal, acquire coating information.

[0030] The start signal is a command signal used to trigger the start of the coating inspection process. The start signal is pre-entered into the system by the staff and can be triggered by the staff pressing the start button on the control interface.

[0031] Coating information refers to the specific parameters and properties related to the coating, including the composition and color of the paint used. This coating information is pre-entered by staff based on relevant information about the paint being used. This paint information is obtained from materials such as the paint packaging instructions or the paint supplier's product manual.

[0032] Step 2: Select the type of detection laser based on the coating information.

[0033] The type of laser used for detection refers to the type of laser suitable for detecting different coatings. Different coatings, due to differences in composition and color, absorb different wavelengths of laser light to varying degrees. Therefore, it is necessary to select the appropriate type of laser for detection based on the coating information. The method for selecting the type of laser is as follows: Staff pre-analyze the appropriate laser type for different coating information through numerous experiments and establish a laser selection database corresponding to coating information and detection laser types in the system. This database records the most suitable detection laser types for coatings with different compositions and colors. When the coating information is obtained, it is compared with the information in the database to determine the corresponding detection laser type.

[0034] Step 3: Control the laser irradiation device to irradiate at the preset laser starting position according to the type of laser being detected, and disassemble the coating information to obtain the standard receiving intensity.

[0035] A laser irradiation device is a device that irradiates a coating surface with a laser.

[0036] The laser starting position is the initial position at which the laser irradiation device emits the laser when the detection begins. The laser starting position is preset by the operator.

[0037] Standard received intensity refers to the intensity of laser light that a receiving area should receive after it has been reflected from a normal coating. The receiving area is the region used to receive the reflected laser light. The standard received intensity is obtained by conducting extensive experiments and data analysis on different coatings beforehand to determine the laser intensity that the receiving area should receive for each coating under the corresponding test laser irradiation. This data is then organized and stored in the system as part of the coating information. The system can directly obtain the standard received intensity for a given coating by reading the coating information.

[0038] Step 4: Obtain the actual received signal strength and the corresponding actual received area.

[0039] Actual received intensity refers to the intensity of the laser light received by the receiving area after it is reflected from the coating surface by the laser emitted by the laser irradiation device during the actual detection process. The method for obtaining the actual received intensity is described in detail in steps 40 to 42.

[0040] The actual receiving area refers to the actual area detected by the receiving area after the laser beam strikes the surface of the coating to be inspected and is reflected. The actual receiving area is obtained as follows: when the laser sensor in the receiving area receives the laser light signal, the area where the laser light signal is detected is marked as the actual receiving area.

[0041] Step 5: Calculate the intensity difference based on the actual received intensity and the standard received intensity.

[0042] The intensity difference refers to the difference between the actual received intensity and the standard received intensity. The intensity difference is obtained by subtracting the standard received intensity from the actual received intensity.

[0043] Step 6: When the intensity difference is greater than the preset error intensity, the actual irradiation area will be obtained based on the actual receiving area, and the actual irradiation area will be defined as the coating defect area.

[0044] Error intensity refers to the allowable fluctuation value of error during normal testing. Error intensity is set by staff based on multiple tests and practical experience.

[0045] The actual irradiated area refers to the area on the coating surface that is actually irradiated by the laser emitted by the laser irradiation device during the detection process. The actual irradiated area is obtained as follows: During the initial detection process, the laser travels from emission to irradiation of the coating surface and then reflects to the receiving area. There is a fixed optical path propagation relationship in this process. This optical path is measured in advance by the staff through multiple experiments to obtain the corresponding positional relationship between the actual irradiated area and the actual receiving area, and this corresponding positional relationship is stored in the system. Thus, the system can directly obtain the actual irradiated area through the actual receiving area and the corresponding relationship.

[0046] A coating defect area refers to an area on the coating surface that has defects, such as an area on the coating surface where no paint has been applied.

[0047] When the intensity difference is greater than the error intensity, it indicates that a part of the coating has defects. It is possible that the coating was not applied to this part of the coating, causing the intensity of the laser reflected to the actual receiving area to be far greater than the normal standard receiving intensity. Therefore, the actual irradiated area is defined as the coating defect area.

[0048] Step 7: Generate a recoating plan based on the defective areas of the coating, and output the recoating plan.

[0049] A touch-up coating scheme refers to a method of repairing coating defects by applying a new coating to the defective areas. For details on how to generate a touch-up coating scheme, please refer to steps 70 to 72.

[0050] This also includes a control method when the strength difference is less than the error strength, the method comprising: Step 60: When the strength difference is less than the error strength, take the absolute value of the strength difference to obtain the absolute difference value.

[0051] The absolute difference refers to the absolute value of the intensity difference. For example, when the actual received intensity is 45 and the standard received intensity is 50, the intensity difference is -5, and the absolute difference is 5 (the value here is only for illustrative purposes and does not represent the actual value, so it is without unit).

[0052] Step 61: When the absolute difference is greater than the error intensity, obtain the area coating image based on the actual irradiated area.

[0053] A regional coating image is an image obtained by photographing an actual irradiated area. Regional coating images can be obtained by taking pictures using equipment such as industrial cameras.

[0054] When the intensity difference is less than the error intensity and the absolute difference is greater than the error intensity, it indicates that the laser intensity received by the actual receiving area is much less than the normal standard receiving intensity. This suggests that some parts of the coating may have uneven coating application, causing the laser irradiated to that part to not only be absorbed but also reflected to other receiving areas that are not the actual receiving area.

[0055] When the absolute difference is less than the error intensity, it indicates that the difference between the actual received intensity and the standard received intensity is within an acceptable fluctuation range, and the coating in the current detection area can be considered normal.

[0056] Step 62: Analyze the regional coating image to obtain the coating shape.

[0057] The coating shape refers to the shape formed on the coating after the paint is applied. The coating shape is obtained by analyzing the regional coating image using image processing techniques, such as edge detection and contour extraction algorithms, to determine the boundaries and shape of the paint on the coating.

[0058] Step 63: Analyze the abnormal reflection path based on the coating shape and the laser starting position.

[0059] Reference Figure 2 An abnormal reflection path refers to the path of a laser beam reflected after it hits the actual irradiated area, as directed by the laser irradiation device at the irradiation position. The abnormal reflection path is obtained by the system through image segmentation, edge extraction, and 3D reconstruction to obtain a 3D topographic model of the coating surface based on the coating shape, and then calculating the abnormal reflection path of the laser beam in conjunction with the laser irradiation position.

[0060] Step 64: Obtain the abnormal receiving area based on the actual irradiation area and the abnormal reflection path, and define the abnormal receiving area as the normal area.

[0061] An abnormal receiving area refers to the portion of the laser beam reflected to an unexpected receiving area due to an abnormal coating shape in the actual irradiated area. The abnormal receiving area is obtained by the system based on the abnormal reflection path and the corresponding position of the actual irradiated area, thus determining the abnormal receiving area where the abnormal reflection path illuminates the receiving area.

[0062] A normal area refers to an area without coating defects. An abnormal receiving area is defined as a normal area because it receives not only the laser light it should have received, but also the laser light reflected from the actual irradiated area due to coating defects. This may cause the laser intensity received by the normal area to far exceed the standard receiving intensity, even though the coated area corresponding to the normal area is actually without defects.

[0063] This also includes a method for determining whether an abnormal reception area is truly a normal area, the method comprising: Step 640: Obtain the illumination angle and illumination height, and obtain the abnormal illumination area based on the abnormal reception area.

[0064] The irradiation angle refers to the angle between the laser emitted by the laser irradiation device at the laser's initial position and the horizontal plane. The irradiation angle is obtained as follows: When inspecting coatings, the laser irradiation device is pre-installed at the laser's initial position by personnel. An initial irradiation angle is set and controlled by the personnel, and this angle is stored in the system. The system can then directly read the relevant data to obtain the irradiation angle.

[0065] Irradiation height refers to the vertical distance between the laser irradiation device and the coating. This irradiation height is also preset by the staff and stored in the system, which can then directly retrieve it.

[0066] The abnormal irradiation area refers to the area on the coating surface that is actually irradiated by the laser, corresponding to the abnormal receiving area. The method for obtaining the abnormal irradiation area is similar to that of the actual irradiation area; it is obtained directly by the system through the abnormal receiving area based on the pre-measured positional relationship between the abnormal receiving area and the abnormal irradiation area.

[0067] Step 641: Obtain the actual irradiation location and the abnormal irradiation location based on the actual irradiation area and the abnormal irradiation area, and obtain the relative path based on the actual irradiation location and the abnormal irradiation location.

[0068] The actual irradiation position refers to the coordinate position of the actual irradiated area in three-dimensional space. The actual irradiation position is obtained by the system analyzing the coating image of the area corresponding to the actual irradiated area, combining it with the laser starting position and optical path propagation relationship stored in the system, calculating the coordinates of the actual irradiated area in three-dimensional space, and obtaining the coordinate information of the area in three-dimensional space.

[0069] The abnormal illumination location refers to the coordinate position of the abnormally illuminated area in three-dimensional space. The method for obtaining the abnormal illumination location is similar to that of the actual illumination location. It involves analyzing the image corresponding to the abnormally illuminated area, combining it with the laser initiation position and optical path propagation relationship stored in the system, to calculate the coordinates of the abnormally illuminated area in three-dimensional space, thus obtaining the coordinate information of the area in three-dimensional space.

[0070] A relative path is a straight line along the horizontal direction between the actual irradiation position and the abnormal irradiation position. A relative path is obtained by connecting the coordinates of two points at the actual irradiation position and the abnormal irradiation position.

[0071] Step 642: Calculate the midpoint based on the actual irradiation position and the abnormal irradiation position, and obtain the vertical path based on the midpoint and the relative path.

[0072] The midpoint is the point located at the midpoint of the relative distance between the actual irradiation position and the abnormal irradiation position. The midpoint is obtained by adding the coordinates of the actual irradiation position and the abnormal irradiation position and then dividing by two.

[0073] A perpendicular path is a path that is perpendicular to a relative path and passes through a midpoint. Perpendicular paths are perpendicular to each other. A perpendicular path is constructed in geometric space, with the midpoint as the foot of the perpendicular. The perpendicular direction of the perpendicular path is determined based on the direction of the relative path, thus determining the specific location and direction of the perpendicular path.

[0074] Step 643: Obtain the position of the verification laser based on the midpoint, illumination angle, illumination height, and vertical path.

[0075] The verification laser position refers to the laser irradiation position used to verify whether an abnormal reception area is a normal area. The verification laser position is obtained as follows: using the midpoint as a reference, select any one of the two directions on the vertical path. The angle between the straight line formed by the midpoint and the verification laser position and the horizontal plane of the coating is the same as the irradiation angle. Furthermore, the vertical height of the verification laser position from the horizontal plane of the coating is consistent with the irradiation height. Therefore, the verification laser position can be obtained through geometric calculation.

[0076] Step 644: Control the laser irradiation device to move to the verification laser position and irradiate along a vertical path, and obtain the verification laser intensity corresponding to the abnormal irradiation area.

[0077] Verification laser intensity refers to the intensity of the laser light reflected from the laser irradiation device after it illuminates the abnormal irradiation area along a vertical path at the verification laser position and is received by the receiving area. The method for obtaining verification laser intensity is the same as that for obtaining actual received intensity: a laser sensor installed on the receiving area first receives the laser's optical signal and converts it into an electrical signal to obtain the verification laser intensity.

[0078] Step 645: Calculate the absolute verification intensity difference based on the verification laser intensity and the standard received intensity.

[0079] The absolute verification intensity difference refers to the absolute value of the difference between the verification laser intensity and the standard received intensity. For example, when the verification laser intensity is 60 and the standard received intensity is 55, the intensity difference is 5, and the absolute verification intensity difference is 5; when the verification laser intensity is 50 and the standard received intensity is 55, the intensity difference is -5, and the absolute verification intensity difference is also 5 (these values ​​are for illustrative purposes only and do not represent actual values, so they are without units).

[0080] Step 646: When the absolute check strength difference is less than the error strength, the abnormal reception area is defined as the normal area.

[0081] When the absolute verification intensity difference is less than the error intensity, it means that the deviation between the laser intensity received in the abnormal receiving area and the standard receiving intensity is within the allowable range, which means that the coating application in the corresponding area is normal and there is no defect problem.

[0082] Step 647: When the absolute verification strength difference is greater than the error strength, the abnormal receiving area is defined as the coating defect area.

[0083] When the absolute verification intensity difference is greater than the error intensity, it indicates that the deviation between the laser intensity received in the abnormal receiving area and the standard receiving intensity exceeds the allowable range, which means that there is indeed a defect in the coating application in that area.

[0084] This also includes a method for moving the laser irradiation device to verify the laser position, the method comprising: Step 6440: Obtain the movement path based on the laser starting position and the verified laser position.

[0085] The movement path refers to the path taken by the laser irradiation device from the laser's starting position to the verification laser position. The movement path is obtained by connecting the coordinates of the laser's starting position and the verification laser position in three-dimensional space, resulting in a straight line. This straight line is the movement path of the laser irradiation device.

[0086] Step 6441: Obtain the path image based on the movement path.

[0087] A path image is an image obtained by photographing a moving path. Path images can be obtained by taking pictures of a camera or other equipment installed on a laser irradiation device.

[0088] Step 6442: Identify the path image to obtain path obstacle features.

[0089] Path obstacle features refer to the characteristic information of obstacles present in a path image, such as the shape and size of the obstacles. Image recognition algorithms can be used to identify the features of potential obstacles in a path image.

[0090] Step 6443: When there are no obstacles on the path, control the laser irradiation device to move to the verification laser position according to the moving path and irradiate according to the vertical path.

[0091] When there are no obstacles on the path, it means that the laser irradiation device can be controlled to move to the verification laser position along the moving path without interfering with the obstacles. Therefore, the laser irradiation device is controlled to move to the verification laser position along the moving path and irradiate along the vertical path, which means irradiating towards the midpoint.

[0092] Step 6444: When path obstacle features exist, obtain the mirror verification position based on the verification laser position and relative path, and control the laser irradiation device to move to the mirror verification position to irradiate according to the vertical path.

[0093] The mirror verification position refers to the position symmetrical to the verification laser position about the relative path. The mirror verification position is obtained by performing a geometric transformation in three-dimensional space, using the relative path as the axis of symmetry. This symmetrical point is the mirror verification position.

[0094] When obstacles are present in the path, it indicates that there are obstacles on the movement path, and the laser irradiation device cannot move to the verification laser position according to the original movement path. At this time, the laser irradiation device is moved to the mirror verification position. Since the mirror verification position and the verification laser position are symmetrical about the relative path, its irradiation effect is theoretically the same as that of the verification laser position. When irradiating along the perpendicular path, it is directed towards the midpoint.

[0095] This also includes: Step 8: Obtain the coating defect area number and detection path.

[0096] The coating defect area number refers to a unique identifier assigned to each area defined as a coating defect area. The coating defect area number is obtained by sequentially numbering the area each time an actual irradiated area is defined as a coating defect area, for example, B1, B2, etc.

[0097] The detection path refers to the path that the laser irradiation device travels during detection. The detection path is planned and entered in advance by the staff based on the shape, size, and other parameters of the items to be detected.

[0098] Step 9: Obtain the adjacent defect area number based on the coating defect area number and the detection path, and search for the adjacent receiving intensity corresponding to the adjacent defect area number from the preset area information database.

[0099] The adjacent defect area number refers to the number corresponding to the coating defect area number adjacent to the coating defect area number. The adjacent defect area number is obtained by searching the coating defect area number forward and backward along the detection path. For example, if the current coating defect area number is B3, and the previous number is B2 and the next number is B4 along the detection path, then B2 and B4 are the adjacent defect area numbers.

[0100] A regional information database is a database specifically designed to store information such as the received intensity of each irradiated area. This database is created by continuously recording and updating relevant information for each irradiated area during the system's inspection of the coating.

[0101] Adjacent receiving intensity refers to the receiving intensity of the receiving area corresponding to the adjacent defect area number. The method for obtaining adjacent receiving intensity is as follows: each time the system irradiates an irradiated area and obtains the corresponding receiving intensity, it stores the receiving intensity of that area in the area information database. The system can directly look up the corresponding adjacent receiving intensity from the area information database based on the adjacent defect area number.

[0102] Step 10: When the actual received intensity is the same as the adjacent received intensity, obtain the current laser device number and the backup laser device number.

[0103] The current laser device number refers to the number of the laser irradiation device currently in use. This number is a unique identifier assigned by the system when the laser irradiation device is installed and put into use.

[0104] The backup laser device number refers to the number of the laser irradiation device that can be used to replace the current laser irradiation device for testing. The backup laser device number is obtained by pre-storing information on all available laser irradiation devices, including the backup laser irradiation device numbers. When the backup laser device number is needed, the system will directly retrieve it from the stored information.

[0105] When the actual received intensity is the same as that of the adjacent received intensity, it indicates that there may be an anomaly in the current detection situation, which may be due to a problem with the current laser irradiation device.

[0106] Step 11: When a backup laser device number exists, replace the laser irradiation device corresponding to the backup laser device number with the laser irradiation device corresponding to the current laser device number.

[0107] When a backup laser device number exists, it means that there is a backup laser irradiation device in the system that can be used to replace the current laser irradiation device. In order to ensure the accuracy and reliability of the detection, the laser irradiation device corresponding to the backup laser device number is replaced with the laser irradiation device corresponding to the current laser device number.

[0108] This also includes: Step 12: When the backup laser device number does not exist, obtain the adjacent defect area corresponding to the adjacent defect area number.

[0109] Adjacent defect areas refer to the defect areas on the coating that correspond to the adjacent defect area numbers. Adjacent defect areas are obtained by the system finding the corresponding areas from the detected coating defect areas based on the adjacent defect area numbers. Because each coating defect area has a unique number, the system can accurately locate adjacent defect areas.

[0110] Step 13: Obtain the correction length based on adjacent defect areas and the detection path.

[0111] The correction length refers to the length of adjacent defect areas along the correction direction. The correction direction refers to the direction along the detection path. The correction length is obtained as follows: the system determines the start and end points of adjacent defect areas along the correction direction based on the detection path, and calculates the distance between these two points to obtain the correction length.

[0112] Step 14: Obtain the correction position based on the correction length and the laser starting position, and control the laser irradiation device to irradiate at the correction position to obtain the corrected receiving intensity.

[0113] The calibration position refers to the position where the laser irradiation device performs calibration irradiation. The calibration position is obtained by using the laser's starting position as a reference and determining the calibration position along the detection path based on the calibration length. For example, if the calibration length is 5 units, moving forward 5 units along the detection path from the laser's starting position will yield the calibration position.

[0114] Step 15: Calculate the absolute correction difference based on the corrected received strength.

[0115] The absolute correction difference refers to the absolute value of the difference between the corrected received strength and the standard received strength. Its calculation method is similar to that of the absolute calibration strength difference. For example, when the corrected received strength is 55 and the standard received strength is 50, the strength difference is 5, and the absolute correction difference is 5; when the corrected received strength is 45 and the standard received strength is 50, the strength difference is -5, and the absolute correction difference is also 5 (these values ​​are for illustrative purposes only and do not represent actual values, therefore they are without units).

[0116] Step 16: When the absolute correction difference is less than the error intensity, define the coating defect area corresponding to the coating defect area number as a normal area.

[0117] When the absolute correction difference is less than the error intensity, it indicates that the deviation between the corrected receiving intensity and the standard receiving intensity is within the allowable range. This means that the coating application in the area corresponding to the coating defect area number is normal and there is no defect. At this point, the previous definition of the coating defect area for that region can be revoked, and it can be reclassified as a normal area to ensure the accuracy of the test results.

[0118] When the absolute correction difference is greater than the error intensity, it indicates that the deviation between the corrected receiving intensity and the standard receiving intensity exceeds the allowable range, meaning that the coating application of the area corresponding to the coating defect area number does indeed have a defect. In this case, the previous definition of the coating defect area for that region should be maintained.

[0119] The methods for generating a recoating scheme based on the defective areas of the coating include: Step 70: Obtain the shape and area of ​​the defect area based on the coating defect area.

[0120] The shape of the defect area refers to the geometric shape of the coating defect area on a plane, which can be determined by edge detection and shape recognition algorithms on the image of the coating defect area.

[0121] The defect area refers to the area occupied by the coating defect area on a plane, which can be obtained through image pixel statistics or geometric calculations.

[0122] Step 71: Obtain the recoating diameter and generate a recoating path based on the recoating diameter, the shape of the defect area, and the area of ​​the defect area.

[0123] The touch-up diameter refers to the diameter of the circular area covered by the touch-up tool (such as a spray gun) during the touch-up operation. This diameter is preset according to the actual touch-up tool and touch-up requirements.

[0124] The method for generating the touch-up path is described in detail in steps 710 to 713.

[0125] Step 72: Generate a recoating plan based on the recoating path and coating information.

[0126] A repair plan is generated based on the repair path and coating information, thereby ensuring the integrity of the coating and improving the efficiency and quality of repair.

[0127] The methods for generating a recoating path based on the recoating diameter, the shape of the defect area, and the area of ​​the defect area include: Step 710: Obtain the minimum width based on the shape and area of ​​the defect region.

[0128] Minimum width refers to the minimum width dimension of the defect area measured in all directions. For example, for a rectangle, the length of its short side can be directly used as the minimum width.

[0129] Step 711: Determine the maximum number of recoatings based on the minimum width and the recoating diameter.

[0130] The maximum number of touch-up coats refers to the theoretical maximum number of times a touch-up tool can coat a defective area without resulting in an excessively thick coating. The maximum number of touch-up coats is determined by dividing the minimum width by the touch-up diameter. If the division is even, the quotient is the maximum number of touch-up coats; otherwise, round down to the nearest integer.

[0131] Step 712: Calculate the total recoating width based on the number of recoating applications and the recoating diameter, and calculate the missing width based on the total recoating width and the minimum width.

[0132] Total touch-up width refers to the total width covered by the touch-up tool according to the number of touch-up applications. It is calculated by multiplying the number of touch-up applications by the touch-up diameter.

[0133] Missing width refers to the difference between the total repaint width and the minimum width, which is obtained by subtracting the total repaint width from the minimum width.

[0134] Step 713: Generate a full-coat path based on the maximum number of touch-up coats and the touch-up diameter, generate a partial-coat path based on the full-coat path and the missing width, and form a touch-up path based on the full-coat path and the partial-coat path.

[0135] Reference Figure 3 Full coating path refers to controlling the touch-up tool to create a coating path according to the maximum number of coats and the coating diameter. Figure 3 In the example shown, the maximum number of recoating strokes is 3. The full-coverage path is generated by uniformly applying recoating strokes along the edge of the defect area, with the recoating diameter as the interval, until the maximum number of recoating strokes is reached. When generating the full-coverage path, it is necessary to ensure that the distance the recoating tool moves each time is equal to the recoating diameter, and the direction of movement is parallel to the edge of the defect area.

[0136] A paint separation path refers to a path created after a full-coverage path has been completed, where a touch-up tool is used to fill in the missing width. The paint separation path is generated by following the edge of the full-coverage path and, at the location corresponding to the missing width, controlling the touch-up tool to fill in the missing width.

[0137] The methods for obtaining the actual received signal strength include: Step 40: Obtain the current received strength.

[0138] The current received intensity refers to the intensity of the laser light emitted by the laser irradiation device, which is reflected back to the receiving area after irradiating the coating surface during the current detection process. The current received intensity is obtained by having a laser sensor installed on the receiving area first receive the laser light signal and convert it into an electrical signal to obtain the current received intensity.

[0139] Step 41: If the current received strength falls within the preset normal strength range, define the current received strength as the actual received strength and input it.

[0140] The normal intensity range refers to a pre-defined range of laser receiving intensity that conforms to normal coating inspection conditions. This range is determined through statistical analysis of multiple experiments and actual test data. If the current received intensity falls within the normal intensity range, it indicates that the detected laser intensity is reasonable and can be defined as the actual received intensity, which is then input into the system.

[0141] Step 42: If the current received strength does not fall within the normal strength range, output an abnormal strength signal.

[0142] An abnormal intensity signal indicates that the current received laser intensity does not fall within the normal range. This signal can be output via audible and visual alerts. When an abnormal intensity signal is output, it indicates a potential problem with the detected laser reception intensity, which could be due to a malfunction in the laser irradiation device, special conditions on the coating surface, or a fault in the laser sensor in the receiving area.

[0143] Based on the same inventive concept, embodiments of the present invention provide an automatic detection system for surface defects in coatings.

[0144] An automatic detection system for surface defects in paint coatings, comprising: The acquisition module is used to acquire coating information, actual received intensity, and the corresponding actual received area. A memory for storing a program for an automatic detection method of defects on the surface of a coating; The processor loads and executes programs from memory.

[0145] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0146] 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. An automatic detection method for surface defects in coatings, characterized in that, include: Step 1: In response to the start signal, acquire coating information; Step 2: Select the type of detection laser based on the coating information; Step 3: Control the laser irradiation device to irradiate at the preset laser starting position according to the type of laser being detected, and disassemble the coating information to obtain the standard receiving intensity; Step 4: Obtain the actual received signal strength and the corresponding actual received area; Step 5: Calculate the intensity difference based on the actual received intensity and the standard received intensity; Step 6: When the intensity difference is greater than the preset error intensity, the actual irradiation area will be obtained based on the actual receiving area, and the actual irradiation area will be defined as the coating defect area. Step 7: Generate a recoating plan based on the defective areas of the coating, and output the recoating plan.

2. The automatic detection method for surface defects of a coating as described in claim 1, characterized in that, It also includes a control method when the strength difference is less than the error strength, the method comprising: Step 60: When the strength difference is less than the error strength, take the absolute value of the strength difference to obtain the absolute difference; Step 61: When the absolute difference is greater than the error intensity, obtain the area coating image based on the actual irradiated area; Step 62: Analyze the regional coating image to obtain the coating shape; Step 63: Analyze the abnormal reflection path based on the coating shape and the laser starting position; Step 64: Obtain the abnormal receiving area based on the actual irradiation area and the abnormal reflection path, and define the abnormal receiving area as the normal area.

3. The automatic detection method for surface defects of a coating as described in claim 2, characterized in that, It also includes a method for determining whether an abnormal reception area is truly a normal area, the method comprising: Step 640: Obtain the illumination angle and illumination height, and obtain the abnormal illumination area based on the abnormal reception area; Step 641: Obtain the actual irradiation location and the abnormal irradiation location based on the actual irradiation area and the abnormal irradiation area, and obtain the relative path based on the actual irradiation location and the abnormal irradiation location. Step 642: Calculate the midpoint based on the actual irradiation position and the abnormal irradiation position, and obtain the vertical path based on the midpoint and the relative path; Step 643: Obtain the verification laser position based on the midpoint, illumination angle, illumination height, and vertical path; Step 644: Control the laser irradiation device to move to the verification laser position and irradiate along a vertical path, and obtain the verification laser intensity corresponding to the abnormal irradiation area; Step 645: Calculate the absolute verification intensity difference based on the verification laser intensity and the standard received intensity; Step 646: When the absolute check strength difference is less than the error strength, the abnormal reception area is defined as the normal area; Step 647: When the absolute verification strength difference is greater than the error strength, the abnormal receiving area is defined as the coating defect area.

4. The automatic detection method for surface defects of a coating as described in claim 3, characterized in that, It also includes a method for controlling the laser irradiation device to move to the calibration laser position, the method comprising: Step 6440: Obtain the movement path based on the laser's starting position and the verified laser position; Step 6441: Obtain the path image based on the movement path; Step 6442: Identify the path image to obtain path obstacle features; Step 6443: When there are no obstacles on the path, control the laser irradiation device to move to the verification laser position according to the moving path and irradiate according to the vertical path; Step 6444: When path obstacle features exist, obtain the mirror verification position based on the verification laser position and relative path, and control the laser irradiation device to move to the mirror verification position to irradiate according to the vertical path.

5. The automatic detection method for surface defects of a coating as described in claim 1, characterized in that, Also includes: Step 8: Obtain the coating defect area number and detection path; Step 9: Obtain the adjacent defect area number based on the coating defect area number and the detection path, and search for the adjacent receiving intensity corresponding to the adjacent defect area number from the preset area information database; Step 10: When the actual received intensity is the same as the adjacent received intensity, obtain the current laser device number and the backup laser device number; Step 11: When a backup laser device number exists, replace the laser irradiation device corresponding to the backup laser device number with the laser irradiation device corresponding to the current laser device number.

6. The automatic detection method for surface defects of a coating as described in claim 5, characterized in that, Also includes: Step 12: When the backup laser device number does not exist, obtain the adjacent defect area corresponding to the adjacent defect area number; Step 13: Obtain the correction length based on adjacent defect areas and the detection path; Step 14: Obtain the correction position based on the correction length and the laser starting position, and control the laser irradiation device to irradiate at the correction position to obtain the corrected receiving intensity; Step 15: Calculate the absolute correction difference based on the corrected received strength; Step 16: When the absolute correction difference is less than the error intensity, define the coating defect area corresponding to the coating defect area number as a normal area.

7. The automatic detection method for surface defects of a coating as described in claim 1, characterized in that, Methods for generating recoating schemes based on coating defect areas include: Step 70: Obtain the shape and area of ​​the defect area based on the coating defect area; Step 71: Obtain the recoating diameter, and generate a recoating path based on the recoating diameter, the shape of the defect area, and the area of ​​the defect area; Step 72: Generate a recoating plan based on the recoating path and coating information.

8. The automatic detection method for surface defects of a coating as described in claim 7, characterized in that, Methods for generating a repainting path based on the repainting diameter, defect region shape, and defect region area include: Step 710: Obtain the minimum width based on the shape and area of ​​the defect region; Step 711: Determine the maximum number of recoating passes based on the minimum width and recoating diameter; Step 712: Calculate the total recoating width based on the number of recoating applications and the recoating diameter, and calculate the missing width based on the total recoating width and the minimum width; Step 713: Generate a full-coat path based on the maximum number of touch-up coats and the touch-up diameter, generate a partial-coat path based on the full-coat path and the missing width, and form a touch-up path based on the full-coat path and the partial-coat path.

9. The automatic detection method for surface defects of a coating as described in claim 1, characterized in that, Methods for obtaining actual received signal strength include: Step 40: Obtain the current received signal strength; Step 41: If the current received strength falls within the preset normal strength range, define the current received strength as the actual received strength and input it; Step 42: If the current received strength does not fall within the normal strength range, output an abnormal strength signal.

10. An automatic detection system for surface defects in coatings, characterized in that, include: The acquisition module is used to acquire coating information, actual received intensity, and the corresponding actual received area. A memory for storing a program for an automatic detection method for surface defects of a coating as described in any one of claims 1 to 9; The processor loads and executes programs from memory.

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