Laser marking control method for watch manufacturing

Abstract

The invention relates to the field of welding technology, and in particular to a laser marking control method for watch manufacturing, comprising: obtaining marking result images respectively obtained after laser marking of watches for multiple times in history; determining the clarity and corner sharpness of each position point of a marking path in each marking according to each marking result image; determining the compensable correction probability of each position point in each marking according to the clarity and corner sharpness; determining the error compensation coefficient of each position point according to the error change trend of the clarity of the same position point in each marking and the difference in the compensable correction probability of adjacent position points in each marking; determining the corrected proportional gain coefficient of each position point according to the error compensation coefficient of each position point and the compensable correction probability in the previous marking; the corrected proportional gain coefficient is used to perform PID control on the laser output power of the corresponding position point in the current marking, thereby improving the marking clarity and the accuracy of laser control.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a laser marking control method for watch manufacturing. Background Art

[0002] With the rapid development of modern manufacturing, especially the increasing demand for precision manufacturing and personalized customization, the application of laser technology in industrial production is becoming more and more extensive. As a non-contact, high-precision processing method, laser marking technology has been widely used in the watch manufacturing industry because of its advantages such as no wear, no pollution, and good permanent marking. Laser marking technology can make fine marks on the surface of metal, ceramic, glass and other materials of watches, such as brand logos, serial numbers, QR codes, etc., which not only improves the anti-counterfeiting performance of the product, but also enhances the appearance texture and brand value of the product.

[0003] In the process of laser marking watches, under fixed marking parameters, the clarity of each position point should always be large and have a small variation range. However, due to the complexity of the actual marking pattern, under fixed marking parameters, the marked pattern is prone to unclear problems, for example: at the relatively sharp corners of the actual laser movement trajectory, the marked pattern is prone to unclear. Summary of the invention

[0004] In order to solve the technical problem of unclear marking patterns, the purpose of the present invention is to provide a laser marking control method for watch manufacturing, and the technical solution adopted is as follows:

[0005] A laser marking control method for watch manufacturing, the method comprising:

[0006] Obtain the marking result images obtained after multiple laser markings of watches in history;

[0007] Determine the clarity and corner sharpness of each position point on the marking path in each marking according to each of the marking result images;

[0008] Determine the compensable correction probability of each of the position points in previous markings according to the clarity and corner sharpness;

[0009] Determine the error compensation coefficient of each position point according to the error change trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking;

[0010] According to the error compensation coefficient of each position point and the compensable correction probability in the previous marking, the corrected proportional gain coefficient corresponding to each position point is determined; the corrected proportional gain coefficient is used to perform proportional-integral-differential control on the laser output power of the corresponding position point in the current marking.

[0011] In one embodiment, determining the clarity and corner sharpness of each position point on the marking path in each marking according to each of the marking result images includes:

[0012] For each of the marking result images, respectively, determine the clarity of each position point on the marking path during the corresponding marking process and the position coordinates of each position point;

[0013] Determining, according to each of the position coordinates, a local moving direction change trend of the marking path at each of the position points during the marking process;

[0014] According to the changing trend of the moving direction corresponding to each of the position points, the sharpness of the corners corresponding to each of the position points during the marking process is determined.

[0015] In one embodiment, the moving direction change trend is measured by the path tangent slope; and determining the moving direction change trend of the local marking path at each position point during the marking process according to each position coordinate includes:

[0016] Determining the path tangent slope at each position point during the marking process according to each position coordinate;

[0017] Determining the corner sharpness corresponding to each of the position points during the marking process according to the change trend of the moving direction corresponding to each of the position points includes:

[0018] Dividing a plurality of local path sections with each of the position points on the marking path as the center; dividing the path sections based on each of the position points on the marking path;

[0019] For each position point on the marking path, the average of the differences between the path tangent slopes of each group of adjacent position points in the local path section where the position point is located is determined to obtain the corner sharpness of the local path section where the position point is located during the marking process.

[0020] In one embodiment, determining the compensable correction probability of each position point in previous markings according to the clarity and corner sharpness includes:

[0021] Determine the clarity error of each position point in each marking process according to the clarity of each position point in each marking process;

[0022] Determine the correlation mean of all marking processes according to the correlation between the clarity and the corner sharpness of each position point in each marking process;

[0023] For each position point in each marking process, the compensable correction probability of the position point in the marking process is determined according to the correlation mean and the clarity error of the position point in the marking process.

[0024] In one embodiment, before determining the error compensation coefficient of each position point according to the error variation trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking, the method further includes:

[0025] According to the clarity of each position point in previous markings, determine the clarity error of each position point in previous markings;

[0026] According to the difference between the clarity errors of the same position point in each group of adjacent markings, the error variation trend of the clarity of the same position point in all the markings is determined.

[0027] In one embodiment, the determining of the error variation trend of the clarity of the same position point in each group of adjacent markings according to the difference between the clarity errors of the same position point in each group of adjacent markings includes:

[0028] Determine the sum of the differences between the clarity errors of the same position points in each group of adjacent markings to obtain a first reference value;

[0029] Determine the sum of the absolute values ​​of the differences between the clarity errors of the same position points in each group of adjacent markings to obtain a second reference value;

[0030] According to the ratio between the first reference value and the second reference value, the error variation trend of the clarity of the same position point in previous markings is determined.

[0031] In one embodiment, the error compensation coefficient of each position point is determined according to the error variation trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking, including:

[0032] For each position point, respectively, determining the difference in compensable correction probability between the position point and an adjacent position point in each marking;

[0033] Determine the mean of the differences in the compensable correction probabilities stated in the previous markings;

[0034] The error compensation coefficient of the position point is determined according to the mean value of the difference and the error variation trend of the clarity of the position point in previous markings.

[0035] In one embodiment, determining the corrected proportional gain coefficient corresponding to each position point according to the error compensation coefficient of each position point and the compensable correction probability in the previous marking includes:

[0036] For each position point, the product of the default proportional gain coefficient and the compensable correction probability of the position point in the previous marking is determined respectively, and then the product is added to the error compensation coefficient of the position point to obtain the corrected proportional gain coefficient corresponding to the position point.

[0037] In one embodiment, after determining the corrected proportional gain coefficients corresponding to the respective position points according to the error compensation coefficients of the respective position points and the compensable correction probability in the previous marking, the method further includes:

[0038] The corrected proportional gain coefficients corresponding to the respective position points are output to the control module in sequence, so that the control module performs proportional-integral-differential control on the laser output power of the corresponding position points in sequence based on the corrected proportional gain coefficients during the current marking process.

[0039] In one embodiment, after determining the corrected proportional gain coefficients corresponding to the respective position points according to the error compensation coefficients of the respective position points and the compensable correction probability in the previous marking, the method further includes:

[0040] After the current marking is completed, the marking result image after the current marking is completed is obtained, and the process returns to execute the steps of determining the clarity and corner sharpness of each position point on the marking path in previous markings according to each of the marking result images and subsequent steps.

[0041] The present invention has the following beneficial effects:

[0042] The marking result images obtained after multiple historical laser marking of watches are obtained, and the clarity and corner sharpness of each position point on the marking path in the previous markings are determined according to each marking result image. The compensable correction probability of each position point in the previous markings is determined according to the clarity and corner sharpness, which can avoid the influence of the angle change on the laser marking path on the clarity of the marking pattern. According to the error change trend of the clarity of the same position point in the previous markings and the difference in the compensable correction probability of adjacent position points in each marking, the error compensation coefficient of each position point is determined, and according to the error compensation coefficient of each position point and the compensable correction probability in the previous marking, the corrected proportional gain coefficient corresponding to each position point is determined. The corrected proportional gain coefficient is used to perform proportional-integral-differential control on the laser output power of the corresponding position point in the current marking, which can accurately control the laser output power of each position point on the laser marking path, avoid the problem of unclear marking pattern when using a fixed laser output power for laser marking, and improve the clarity of the laser marking pattern and the accuracy of laser control. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 An application environment diagram of a laser marking control method for watch manufacturing provided by one embodiment of the present invention;

[0045] Figure 2 A schematic flow chart of a laser marking control method for watch manufacturing provided by one embodiment of the present invention;

[0046] Figure 3 A schematic diagram showing the errors in watch marking results using the traditional method;

[0047] Figure 4 A schematic diagram of a flow chart for determining a compensable correction probability provided by an embodiment of the present invention;

[0048] Figure 5 A schematic diagram of a flow chart for determining an error compensation coefficient provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the laser marking control method for watch manufacturing proposed by the present invention, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0050] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0051] During the manufacturing process of watches, laser is used to engrave the required patterns or texts, such as brand logos, serial numbers or QR codes, at the corresponding positions of the watches. The specific process of watch manufacturing is as follows:

[0052] 1. Design and drawing: First, you need to design and draw according to the requirements of the watch brand and model, determine the size, lines and fonts of the dial, and use computer-aided design (CAD) software to generate the marking pattern and import it into the laser marking control system.

[0053] 2. Laser marking: The laser marking control system uses the serpentine scanning method to plan the laser travel path of the current marking pattern, thereby obtaining the laser motion trajectory of the marking pattern, and using a professional laser engraving machine to engrave the marking pattern on the watch dial.

[0054] 3. PVD treatment: PVD (Physical Vapor Deposition) is an important surface treatment process, mainly used to form a thin and uniform functional or decorative coating on the surface of watch parts. PVD technology converts the material from solid to gas by physical methods, and then deposits it on the surface of the substrate to form a thin film, achieving a more beautiful effect.

[0055] In the process of laser marking, the marking process is usually precisely controlled by controlling multiple parameters such as laser output power, scanning speed and focal length. The laser output power controls the energy of the laser beam and affects the depth and clarity of the marking pattern. The scanning speed controls the speed at which the laser beam moves on the surface of the material, affecting the speed and quality of the marking pattern. The focal length adjusts the focus position of the laser beam to ensure the accuracy and consistency of the marking pattern.

[0056] The laser marking control method for watch manufacturing in each embodiment of the present application is a control method proposed for the marking process of the above-mentioned laser engraving machine engraving the marking pattern on the watch. Through this method, the laser output power in the marking process can be controlled in real time and accurately, thereby improving the clarity of the laser marking pattern.

[0057] The following specifically describes a laser marking control method for watch manufacturing provided by the present invention in conjunction with the accompanying drawings.

[0058] The laser marking control method for watch manufacturing provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the image acquisition device 102 and the computer device 104 communicate with each other, the computer device 104 and the control module 106 communicate with each other, and the control module 106 and the laser scribing device 108 communicate with each other. The laser scribing device 108 can mark on the watch 110, and the image acquisition device 102 can capture the image of the pattern on the marked watch 110 to obtain the marking result image. The computer device 104 can obtain the marking result image from the image acquisition device 102, and then execute the laser marking control method for watch manufacturing in each embodiment of the present application based on the marking result image to obtain the corrected proportional gain coefficient corresponding to each position point, and output the corrected proportional gain coefficient corresponding to each position point to the control module 106. The control module 106 can control the laser output power of the laser scribing device 108 during the marking process according to the corrected proportional gain coefficient. Among them, the image acquisition device 102 can be an industrial camera or other device for image acquisition. The computer device 104 may be, but is not limited to, various chips, personal computers, laptops, smart phones, tablet computers, IoT devices, portable wearable devices, etc. The control module 106 may be a proportional integral derivative controller (PID controller).

[0059] See also Figure 2 , which shows a method flow chart of a laser marking control method for watch manufacturing provided by an embodiment of the present invention, comprising the following steps:

[0060] Step 202, obtaining the marking result images obtained after multiple laser markings of watches in history.

[0061] Among them, marking refers to using laser to carve patterns on the surface of a watch. The marking result image is an image obtained by capturing the pattern on the marked watch. It can be understood that the same pattern is marked each time, but due to slight errors in the actual marking process, the patterns actually marked on the watch will be slightly different, so there are differences between the marking result images.

[0062] In one embodiment, after a preset number of markings are performed using fixed laser output power, scanning speed, anxiety and other parameters, step 202 and subsequent steps can be started to obtain the historical marking result images, and the laser output power in each subsequent marking can be controlled based on the historical marking result images. For example, the preset number can be 10 times. That is, after completing 10 markings using fixed laser output power, scanning speed, anxiety and other parameters, step 202 can be executed to obtain the marking result images obtained after the 10 markings and the subsequent steps can be executed to control the laser output power during the 11th marking process. After completing the 11th marking, the marking result image after the 11th marking can be obtained again, and all the marking result images from 1 to 11 markings can be combined to control the laser output power during the 12th marking process, and so on.

[0063] Step 204, determining the clarity and corner sharpness of each position point on the marking path in each marking according to each marking result image.

[0064] Among them, the position point is a point selected from the marking path. The corner sharpness is used to measure the sharpness of the corner of the marking path in the local area where the position point is located.

[0065] In one embodiment, multiple position points may be selected from the marking path at a preset interval, for example, the preset interval may be 0.01 cm.

[0066] In one embodiment, the various position points may be sorted according to the direction of the actual moving path of the laser.

[0067] In one embodiment, the clarity of the position point can be measured by a clarity score. The clarity score of each position point can be determined based on the color information, detail information, edge clarity and other information at each position point in the marking result image. In one embodiment, the color information may include whether the color and depth at the position point are uniform and consistent, and whether there is no obvious color difference or different depths. The detail information may include whether the details at the position point are complete and clear, without missing or broken lines. The edge clarity may include whether the edge at the position point is clear and sharp, without blur or burrs.

[0068] In one embodiment, the clarity of each position point on the marking path in each marking process can be determined through a neural network based on each marking result image.

[0069] In one embodiment, the clarity score ranges from [0, 1], and a higher clarity score indicates greater clarity.

[0070] Step 206, determining the compensable correction probability of each position point in previous markings according to the clarity and corner sharpness.

[0071] The compensable correction probability is used to measure the probability that the marking error generated at any position point in any marking process can be compensated and corrected.

[0072] In one embodiment, the average value of the correlation between the clarity and the corner sharpness of each position point in each marking process can be determined according to the correlation between the clarity and the corner sharpness of each position point in each marking process, and the compensable correction probability of each position point in each marking process can be determined according to the correlation average value and the clarity of the position point in the marking process. The compensable correction probability is negatively correlated with the clarity and positively correlated with the correlation average.

[0073] It can be understood that in the process of laser marking, the entire watch marking process is usually completed by fixing various parameters such as laser output power, scanning speed and focal length. When other parameters except laser output power remain fixed, the greater the laser output power, the greater the energy of the laser beam, which can produce deeper melting, vaporization or chemical reaction on the surface of the material, thereby forming a deeper pattern. However, due to the fact that in the actual marking process of watch manufacturing, under fixed parameters, the clarity of each position point should always be large and have a small variation range, however, due to the relative complexity of the actual pattern, the actual laser marking path has relatively sharp corners. Therefore, when other parameters except laser output power remain fixed, if the same power laser is still used for marking, the final marking pattern will be unclear. Therefore, the corner sharpness at each position point on the laser marking path affects the clarity. Therefore, in this step, the compensable correction probability can be accurately determined based on the clarity and corner sharpness, and then the proportional gain coefficient can be compensated, thereby accurately controlling the laser output power to achieve clarity of the marking pattern and avoid the influence of the angle change of the actual laser marking path on the clarity of the marking pattern at different powers.

[0074] Step 208 , determining the error compensation coefficient of each position point according to the error variation trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking.

[0075] The error variation trend of the clarity of the same position point in all previous markings refers to the variation trend of the clarity error of the same position point as the number of markings increases. The error compensation coefficient of any position point is used to compensate the proportional gain coefficient at the position point.

[0076] It can be understood that in all marking processes, since all parameters except the laser output power remain fixed, different marking processes require the same amount of time. Therefore, the actual coordinate positions of the position points with the same serial number in different marking processes are the same.

[0077] In one embodiment, for each position point, the error compensation coefficient of the position point is determined according to the error variation trend of the clarity of the position point in previous markings and the difference in the compensable correction probability between the position point and the adjacent position point in each marking. In one embodiment, the adjacent position point of the position point may be the next position point of the position point.

[0078] In one embodiment, the error compensation coefficient is positively correlated with the error variation trend of the definition and is positively correlated with the difference in compensable correction probabilities of adjacent position points.

[0079] It can be understood that when the marking pattern itself does not change, due to the different complexity of the local path under different actual marking patterns, that is, the amplitude and number of turns required for different paths are significantly different, if the proportional gain coefficient is directly corrected according to the compensable correction probability of a single position point obtained in step 206, it is easy to cause the final PID-controlled laser output power to have too large a power difference between the two position points, and the actual power adjustment requires a certain amount of time, resulting in an insignificant error elimination effect. Therefore, in this step, according to the difference in the compensable correction probability of adjacent position points in each marking, the error compensation coefficient of each position point can be accurately determined, so as to compensate the proportional gain coefficient more accurately, thereby accurately controlling the laser output power to achieve a clear marking pattern. In addition, since the marking process is in a continuous process, the laser output device itself causes the temperature to rise due to energy conversion. At this time, the actual output laser power is different from the power scalar, so the error generated at the same position point has a probability of changing to a certain extent. Therefore, in this step, the error compensation coefficient of each position point is accurately determined according to the error change trend of the clarity point at the same position in previous markings, which can accurately reflect the influence of the error accumulation of the clarity error at the same position point in the control process, so as to more accurately compensate the proportional gain coefficient, thereby accurately controlling the laser output power to achieve clear marking patterns.

[0080] Step 210, according to the error compensation coefficient of each position point and the compensable correction probability in the previous marking, determine the corrected proportional gain coefficient corresponding to each position point; the corrected proportional gain coefficient is used to perform proportional-integral-differential control on the laser output power of the corresponding position point in the current marking.

[0081] Among them, proportional integral derivative control (PID control) is a method of controlling the controlled object by forming a control deviation based on a given value and an actual output value, and forming a control quantity through a linear combination of the deviation in proportion, integration and differentiation. Proportional integral derivative control contains three important parameters: proportional gain coefficient, integral time and differential time. The proportional gain coefficient determines the response speed of the system to the error. If the proportional gain coefficient is too small, it will cause overshoot or stability problems during the adjustment process. Excessive adjustment will cause system oscillation or instability. Therefore, it is necessary to determine the appropriate proportional gain coefficient based on the response speed and the influence of the error to ensure that the system remains stable during the adjustment process.

[0082] In one embodiment, for each position point, the default proportional gain coefficient may be corrected according to the error compensation coefficient of the position point and the compensable correction probability of the position point in the previous marking to obtain a corrected proportional gain coefficient corresponding to the position point.

[0083] In one embodiment, the computer device can output the corrected proportional gain coefficient corresponding to each position point to the control module in turn, and the control module can perform proportional-integral-differential control on the laser output power of each position point in turn based on the corrected proportional gain coefficient corresponding to each position point in the current marking.

[0084] In one embodiment, after the current marking is completed, the marking result image after the current marking is completed can be obtained, and combined with the previously obtained marking result images, the process returns to step 204 to determine the clarity and corner sharpness of each position point on the marking path in previous markings and subsequent steps based on each marking result image, so as to control subsequent marking.

[0085] In the above-mentioned laser marking control method for watch manufacturing, the marking result images obtained after multiple historical watch laser markings are obtained, and the clarity and corner sharpness of each position point on the marking path in the previous markings are determined based on each marking result image. Based on the clarity and corner sharpness, the compensable correction probability of each position point in the previous markings is determined, which can avoid the influence of the angle change on the laser marking path on the clarity of the marking pattern. According to the error change trend of the clarity of the same position point in the previous markings and the difference in the compensable correction probability of adjacent position points in each marking, the compensable correction probability of each position point in the previous markings is determined. Determine the error compensation coefficient of each position point, and determine the corrected proportional gain coefficient corresponding to each position point according to the error compensation coefficient of each position point and the compensable correction probability in the previous marking. The corrected proportional gain coefficient is used to perform proportional integral differential control on the laser output power of the corresponding position point in the current marking, which can accurately control the laser output power of each position point on the laser marking path, avoiding the problem of unclear marking pattern when using fixed laser output power for laser marking, and improving the clarity of the laser marking pattern and the accuracy of laser control. Figure 3 As shown, the marking result pattern after traditional laser marking is displayed. It can be seen that there is an obvious marking error in the dotted box. The laser marking control method for watch manufacturing in each embodiment of the present application can reduce this error.

[0086] In one embodiment, the clarity and corner sharpness of each position point on the marking path in each marking process are determined according to each marking result image, including: determining the clarity of each position point on the marking path and the position coordinates of each position point during the corresponding marking process for each marking result image respectively; determining the local moving direction change trend of the marking path at each position point during the marking process according to each position coordinate; determining the corner sharpness corresponding to each position point during the marking process according to the moving direction change trend corresponding to each position point.

[0087] In one embodiment, the path tangent slope of the marking path at each position point during the marking process can be determined according to each position coordinate. According to the path tangent slope corresponding to each position point, the corner sharpness corresponding to each position point during the marking process can be determined. The path tangent slope is used to measure the local movement direction change trend of the marking path at the position point.

[0088] In one embodiment, the path tangent slope of the marking path at each position point during the marking process may be determined according to each position coordinate by a first-order derivative.

[0089] In the above embodiment, for each marking result image, the clarity of each position point on the marking path during the corresponding marking process and the position coordinates of each position point are determined, and the local moving direction change trend of the marking path at each position point during the marking process is determined according to each position coordinate. According to the moving direction change trend corresponding to each position point, the corner sharpness corresponding to each position point during the marking process is determined, and the corner sharpness of each position point can be accurately determined.

[0090] In one embodiment, the trend of change in moving direction is measured by the slope of the path tangent; according to each position coordinate, the trend of change in moving direction of the local marking path at each position point in the marking process is determined, including: according to each position coordinate, the slope of the path tangent at each position point in the marking process is determined; according to the trend of change in moving direction corresponding to each position point, the corner sharpness corresponding to each position point in the marking process is determined, including: taking each position point on the marking path as the center, dividing a plurality of local path segments; for each position point on the marking path, determining the average of the differences between the path tangent slopes of each group of adjacent position points in the local path segment where the position point is located, and obtaining the corner sharpness of the local path segment where the position point is located during the marking process.

[0091] In one embodiment, each position point on the marking path can be taken as the center, and a segment consisting of the position point and two adjacent position points of the position point can be used as a local path segment. That is, a local path segment includes three position points.

[0092] In other embodiments, a segment consisting of a location point and surrounding 4 or 6 location points may be used as a local path segment, that is, a local path segment includes 5 or 7 location points, that is, the length of the local path segment is not limited.

[0093] In one embodiment, for each position point on the marking path, the difference between the path tangent slopes of each group of adjacent position points in the local path segment where the position point is located is determined, and then the average of the differences between the path tangent slopes is used to determine the corner sharpness of the local path segment where the position point is located during the marking process.

[0094] In the above embodiment, a plurality of local path segments are divided with each position point on the marking path as the center, and for each position point on the marking path, the mean value of the difference between the path tangent slopes of each group of adjacent position points in the local path segment where the position point is located is determined, so that the corner sharpness of the local path segment where the position point is located during the marking process can be accurately determined.

[0095] In one embodiment, Figure 4 As shown, step 206 determines the compensable correction probability of each position point in previous markings according to the clarity and corner sharpness, including the following steps:

[0096] Step 402, determining the clarity error of each position point in each marking process according to the clarity of each position point in each marking process.

[0097] In one embodiment, the clarity error of a location point is negatively correlated with the clarity of the location point.

[0098] In one embodiment, the clarity error of the location point may be determined based on the difference between 1 and the clarity of the location point.

[0099] Step 404: Determine the correlation mean of all marking processes according to the correlation between the clarity of each position point and the corner sharpness in each marking process.

[0100] In one embodiment, the correlation between the clarity and the corner sharpness of each position point in each marking process can be determined by the Pearson correlation coefficient, and then the average of the correlations of all the marking processes can be determined to obtain the correlation mean.

[0101] It can be understood that the clarity corresponding to each position point in the marking process can form a clarity data sequence, and the corner sharpness corresponding to each position point can form a corner sharpness sequence. By combining the clarity data sequence and the corner sharpness sequence through the Pearson correlation coefficient, the correlation between the clarity and the corner sharpness of each position point in the marking process can be obtained. By traversing each marking process and averaging the correlation of each marking process, the average of the correlation of each marking process can be obtained.

[0102] In one embodiment, the value range of the correlation mean is [-1, 1]. The closer the correlation mean is to 1, the greater the correlation between the clarity and the corner sharpness of the marking path, that is, the greater the impact of the corner sharpness on the clarity of the marking result.

[0103] Step 406 , for each position point in each marking process, determine the compensable correction probability of the position point in the marking process according to the correlation mean and the clarity error of the position point in the marking process.

[0104] In one embodiment, the compensable correction probability is positively correlated with the clarity error and positively correlated with the correlation mean.

[0105] In one embodiment, the compensable correction probability of the position point in the marking process may be determined according to the product between the correlation mean and the definition error of the position point in the marking process.

[0106] In one embodiment, the compensable correction probability of a position point in any marking process can be determined according to the following formula:

[0107]

[0108] Among them, i represents any position point. It represents the compensable correction probability of position i in any marking process. Indicates the clarity of position point i. Represents the clarity error of position point i. It represents a clarity data sequence composed of the clarity of each position point in any marking process. It represents the corner sharpness data sequence composed of the corner sharpness of each position point in any marking process. It represents the mean value of the correlation between the clarity of each position point and the sharpness of the corner during each marking process.

[0109] Understandable, clear The lower the value, the greater the clarity error. The larger the value, the more likely the compensation probability can be corrected. The larger the compensation probability, the With clarity Negatively correlated with clarity error The greater the correlation between the clarity of each position point and the corner sharpness during the marking process, the greater the impact of the corner sharpness on the clarity of the marking result, and the compensation probability can be corrected. The larger the compensation probability, the Correlation with mean There is a positive correlation.

[0110] In the above embodiment, the clarity error of each position point in each marking process is determined according to the clarity of each position point in each marking process, and the correlation mean of each marking process is determined according to the correlation between the clarity of each position point and the corner sharpness in each marking process. For each position point in each marking process, the compensable correction probability of the position point in the marking process can be accurately determined according to the correlation mean and the clarity error of the position point in the marking process, and then the proportional gain coefficient can be compensated, so as to accurately control the laser output power to achieve the clarity of the marking pattern and avoid the influence of the angle change of the actual laser marking path on the clarity of the marking pattern at different powers.

[0111] In one embodiment, before determining the error compensation coefficient of each position point based on the error change trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking, the method also includes: determining the clarity error of each position point in previous markings based on the clarity of each position point in previous markings; determining the error change trend of the clarity of the same position point in previous markings based on the difference between the clarity errors of the same position point in each group of adjacent markings.

[0112] The term "adjacent marking" refers to two adjacent markings, and the two adjacent markings constitute a group of adjacent markings.

[0113] In one embodiment, the clarity error of a location point is negatively correlated with the clarity of the location point.

[0114] In one embodiment, the clarity error of the location point may be determined based on the difference between 1 and the clarity of the location point.

[0115] In one embodiment, the clarity error of each position point in each marking is determined according to the clarity of each position point in each marking, and the error change trend of the clarity of the same position point in each group of adjacent markings can be accurately determined according to the difference between the clarity errors of the same position point in each group of adjacent markings.

[0116] In one embodiment, according to the difference between the clarity errors of the same position points in each group of adjacent markings, the error change trend of the clarity of the same position points in previous markings is determined, including: determining the sum of the differences between the clarity errors of the same position points in each group of adjacent markings to obtain a first reference value; determining the sum of the absolute values ​​of the differences between the clarity errors of the same position points in each group of adjacent markings to obtain a second reference value; and determining the error change trend of the clarity of the same position points in previous markings according to the ratio between the first reference value and the second reference value.

[0117] In one embodiment, the ratio between the first reference value and the second reference value has a value range of [-1, 1]. The ratio reflects the trend of the overall change of the definition error of the same position point in the previous marking in the increasing or decreasing direction. The closer the ratio is to 1, the more drastic the change of the definition error of the same position point in the previous marking is in the increasing direction. The closer the ratio is to -1, the more drastic the change of the definition error of the same position point in the previous marking is in the decreasing direction.

[0118] In one embodiment, the error variation trend of the clarity of the same position point in previous markings may be determined according to the absolute value of the ratio between the first reference value and the second reference value.

[0119] In one embodiment, the error variation trend of the clarity of the same position point in previous markings can be determined according to the following formula:

[0120]

[0121] in, Indicates the error change trend of the clarity of position i in all previous markings. j represents any marking. N represents the total number of historical markings. Indicates the clarity of position point i in the jth marking. Represents the clarity error of position point i in the jth marking. Indicates the clarity of position point i in the j+1th marking. Indicates the clarity error of position i in the j+1th marking. Indicates the first reference value. Indicates the second reference value. It represents the ratio between the first reference value and the second reference value, and its value range is [-1,1]. This ratio reflects the overall change trend of the clarity error of the same position point in previous markings in the increasing or decreasing direction.

[0122] In the above embodiment, the sum of the differences between the clarity errors of the same position points in each group of adjacent markings is determined to obtain a first reference value, and the sum of the absolute values ​​of the differences between the clarity errors of the same position points in each group of adjacent markings is determined to obtain a second reference value. Based on the ratio between the first reference value and the second reference value, the error change trend of the clarity of the same position points in previous markings can be accurately determined.

[0123] In one embodiment, Figure 5 As shown, step 208 determines the error compensation coefficient of each position point according to the error change trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking, including the following steps:

[0124] Step 502 : for each position point, determine the difference in compensable correction probability between the position point and adjacent position points in each marking.

[0125] Among them, the difference in compensable correction probability is a positive number, that is, the absolute value is taken after subtraction.

[0126] In one embodiment, the adjacent position point of a position point may be the next position point of the position point. That is, for each position point, the difference in the compensable correction probability between the position point and the next position point in each marking is determined.

[0127] Step 504, determining the average of the differences in compensable correction probabilities in previous markings.

[0128] Step 506, determining the error compensation coefficient of the position point according to the mean value of the difference and the error variation trend of the clarity of the position point in previous markings.

[0129] In one embodiment, the error compensation coefficient is positively correlated with the mean of the difference and is positively correlated with the error variation trend of the clarity.

[0130] In one embodiment, the error compensation coefficient of the position point may be determined according to the product of the mean value of the difference and the error variation trend of the clarity of the position point in previous markings.

[0131] In one embodiment, the error compensation coefficient of the position point can be determined according to the following formula:

[0132]

[0133] in, Represents the error compensation coefficient of position point i. Indicates the error change trend of the clarity of position i in all previous markings. j represents any marking. N represents the total number of historical markings. Represents the difference in compensable correction probability between position point i and position point i+1. It represents the mean of the difference in the compensable correction probability between position point i and the adjacent position point i+1 in all previous markings.

[0134] It can be understood that in the historical marking process, the smaller the change in the clarity of the same position point itself with the increase in the number of markings, the smaller the error accumulation effect of the actual clarity error of the position point based on the same proportional gain coefficient during the control process, and the smaller the proportional gain coefficient compensation for any position point. Therefore, the error compensation coefficient of position point i is Error trend of clarity of position i in previous markings The difference in the compensable correction probability between position point i and position point i+1 is The larger the value is, the greater the power adjustment requirement of location point i is. Therefore, the error compensation coefficient of location point i is The difference between the compensable correction probability of position i and position i+1 There is a positive correlation. Error compensation coefficient The larger it is, the greater the cumulative effect of the error will be, and the higher the compensation for the proportional gain coefficient will be.

[0135] In the above embodiment, for each position point, the difference in compensable correctable probabilities between the position point and the adjacent position point in each marking is determined, and the average of the differences in compensable correctable probabilities in all previous markings is determined. According to the average of the differences and the error change trend of the clarity of the position point in all previous markings, the error compensation coefficient of the position point can be accurately determined, and the influence of the error accumulation of the clarity error of the same position point in the control process can be accurately reflected, so as to more accurately compensate the proportional gain coefficient, thereby precisely controlling the laser output power to achieve clarity of the marking pattern.

[0136] In one embodiment, based on the error compensation coefficient of each position point and the compensable correction probability in the previous marking, the corrected proportional gain coefficient corresponding to each position point is determined, including: for each position point, determining the product of a default proportional gain coefficient and the compensable correction probability of the position point in the previous marking, and then adding the product to the error compensation coefficient of the position point to obtain the corrected proportional gain coefficient corresponding to the position point.

[0137] In one embodiment, the corrected proportional gain coefficient corresponding to the position point may be determined according to the following formula:

[0138]

[0139] in, Represents the corrected proportional gain coefficient corresponding to position point i. Indicates the default proportional gain factor. It indicates the compensable correction probability of position point i in the last marking. Represents the error compensation coefficient of position point i.

[0140] In the above embodiment, for each position point, the product of the default proportional gain coefficient and the compensable correction probability of the position point in the previous marking is determined, and then the product is added to the error compensation coefficient of the position point to obtain the corrected proportional gain coefficient corresponding to the position point, so that the corrected proportional gain coefficient corresponding to each position point can be determined in real time and accurately.

[0141] In one embodiment, after determining the corrected proportional gain coefficient corresponding to each position point according to the error compensation coefficient of each position point and the compensable correction probability in the previous marking, the method also includes: outputting the corrected proportional gain coefficient corresponding to each position point to the control module in turn, so that the control module performs proportional-integral-differential control on the laser output power of the corresponding position point in turn based on the corrected proportional gain coefficient in the current marking.

[0142] In one embodiment, during the current marking, the control module determines the real-time proportional-integral-differential control strategy for each position point based on the corrected proportional gain coefficient, and determines the laser power output of the position point passed in real time at each moment according to the real-time proportional-integral-differential control strategy to control the real-time laser output power.

[0143] In the above embodiment, the corrected proportional gain coefficient corresponding to each position point is output to the control module in turn, so that the control module can perform proportional-integral-differential control on the laser output power of the corresponding position point in turn based on the corrected proportional gain coefficient during the current marking, thereby achieving real-time and precise control of the watch laser marking.

[0144] In one embodiment, after determining the corrected proportional gain coefficient corresponding to each position point according to the error compensation coefficient of each position point and the compensable correction probability in the previous marking, the method also includes: after the current marking is completed, obtaining the marking result image after the current marking is completed, returning to execute according to each marking result image, determining the clarity and corner sharpness of each position point on the marking path in previous markings and subsequent steps.

[0145] In the above embodiment, after the current marking is completed, the marking result image after the current marking is completed is obtained, and the execution is returned to determine the clarity and corner sharpness of each position point on the marking path in previous markings and subsequent steps based on each marking result image, so that subsequent marking can continue to be performed based on the marking result images of each marking that has been completed in history, and the data can be continuously updated as the number of markings increases, thereby improving the accuracy of marking.

[0146] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0147] It should be noted that the data involved in this application (including but not limited to data used for analysis, stored data, displayed data, etc.) are all data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0148] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0149] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

[0150] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0151] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A laser marking control method for watch manufacturing, characterized in that: The method comprises: Obtain the marking result images obtained after multiple laser markings on watches; Determine the clarity and corner sharpness of each position point on the marking path in each marking according to each of the marking result images; Determine the compensable correction probability of each of the position points in previous markings according to the clarity and corner sharpness; The method for obtaining the compensable correction probability is as follows: according to the clarity of each position point in each marking process, determine the clarity error of each position point in each marking process; according to the correlation between the clarity of each position point and the corner sharpness in each marking process, determine the correlation mean of each marking process; for each position point in each marking process, according to the correlation mean and the clarity error of the position point in the marking process, determine the compensable correction probability of the position point in the marking process; Determine the error compensation coefficient of each position point according to the error change trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking; The method for obtaining the error compensation coefficient is as follows: for each position point, determining the difference in compensable correctable probabilities between the position point and adjacent position points in each marking; determining the average of the differences in the compensable correctable probabilities in previous markings; and determining the error compensation coefficient of the position point according to the average of the differences and the error change trend of the clarity of the position point in previous markings; According to the error compensation coefficient of each position point and the compensable correction probability in the previous marking, the corrected proportional gain coefficient corresponding to each position point is determined; the corrected proportional gain coefficient is used to perform proportional-integral-differential control on the laser output power of the corresponding position point in the current marking.

2. The laser marking control method for watch manufacturing according to claim 1, characterized in that: Determining the clarity and corner sharpness of each position point on the marking path in each marking according to each of the marking result images includes: For each of the marking result images, respectively, determining the clarity of each position point on the marking path during the corresponding marking process and the position coordinates of each position point; Determining, according to each of the position coordinates, a local moving direction change trend of the marking path at each of the position points during the marking process; According to the changing trend of the moving direction corresponding to each of the position points, the sharpness of the corners corresponding to each of the position points during the marking process is determined.

3. The laser marking control method for watch manufacturing according to claim 2, characterized in that: The moving direction change trend is measured by the path tangent slope; the determining of the moving direction change trend of the local marking path at each position point during the marking process according to each position coordinate includes: Determining the path tangent slope at each position point during the marking process according to each position coordinate; Determining the corner sharpness corresponding to each of the position points during the marking process according to the change trend of the moving direction corresponding to each of the position points includes: Dividing a plurality of local path sections with each of the position points on the marking path as the center; For each position point on the marking path, the average of the differences between the path tangent slopes of each group of adjacent position points in the local path section where the position point is located is determined to obtain the corner sharpness of the local path section where the position point is located during the marking process.

4. The laser marking control method for watch manufacturing according to claim 1, characterized in that: Before determining the error compensation coefficient of each position point according to the error variation trend of the clarity of the same position point in previous markings and the difference in the compensable correction probability of adjacent position points in each marking, the method further includes: According to the clarity of each position point in previous markings, determine the clarity error of each position point in previous markings; According to the difference between the clarity errors of the same position point in each group of adjacent markings, the error variation trend of the clarity of the same position point in all the markings is determined.

5. The laser marking control method for watch manufacturing according to claim 4, characterized in that: Determining the error variation trend of the clarity of the same position point in each group of adjacent markings according to the difference between the clarity errors of the same position point in each group of adjacent markings includes: Determine the sum of the differences between the clarity errors of the same position points in each group of adjacent markings to obtain a first reference value; Determine the sum of the absolute values ​​of the differences between the clarity errors of the same position points in each group of adjacent markings to obtain a second reference value; According to the ratio between the first reference value and the second reference value, the error variation trend of the clarity of the same position point in previous markings is determined.

6. The laser marking control method for watch manufacturing according to claim 1, characterized in that: The method of determining the corrected proportional gain coefficients corresponding to the respective position points according to the error compensation coefficients of the respective position points and the compensable correction probability in the previous marking comprises: For each position point, the product of the default proportional gain coefficient and the compensable correction probability of the position point in the previous marking is determined respectively, and then the product is added to the error compensation coefficient of the position point to obtain the corrected proportional gain coefficient corresponding to the position point.

7. The laser marking control method for watch manufacturing according to claim 1, characterized in that: After determining the corrected proportional gain coefficients corresponding to the respective position points according to the error compensation coefficients of the respective position points and the compensable correction probability in the previous marking, the method further includes: The corrected proportional gain coefficients corresponding to the respective position points are output to the control module in sequence, so that the control module performs proportional-integral-differential control on the laser output power of the corresponding position points in sequence based on the corrected proportional gain coefficients during the current marking process.

8. The laser marking control method for watch manufacturing according to claim 1, characterized in that: After determining the corrected proportional gain coefficients corresponding to the respective position points according to the error compensation coefficients of the respective position points and the compensable correction probability in the previous marking, the method further includes: After the current marking is completed, the marking result image after the current marking is completed is obtained, and the process returns to execute the steps of determining the clarity and corner sharpness of each position point on the marking path in previous markings according to each of the marking result images and subsequent steps.

Images