OCT penetration detection light beam position correction method for flight welding and welding method

Abstract

The invention discloses an OCT penetration depth detection light beam position correction method for flight welding and a welding method, and belongs to the technical field of laser welding. On the basis of determining a flight welding process and a flight welding seam track, the flight welding seam track is converted into a static welding seam track, and the static welding seam track is converted into a static welding seam track; static welding spots are obtained on the static welding seam track for a static welding test, detection light beam position compensation coordinates of all the static welding spots are obtained, and detection light beam position correction coordinates of corresponding flight welding spots on the flight welding seam track are obtained based on conversion of the position compensation coordinates; and the position correction coordinates are fitted to obtain a position correction file of the detection light beam under flight welding, so that position correction of the detection light beam in the flight welding process is completed. According to the method, the steps are simple, operation is convenient and fast, conditions are provided for accurate control over the position of the detection light beam in the flying welding process, the flying welding quality of the workpiece is guaranteed, the machining efficiency and quality of the workpiece are improved, and good economic benefits are achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser welding, and particularly relates to an OCT fusion depth detection beam position correction method for flight welding and a welding method. BACKGROUND

[0002] With the continuous development of China's industrial technology, the demand for laser welding is increasing, and the quality requirements for laser welding are also increasing, which promotes the rapid development of related technologies. In the process of laser welding, the detection of the welding quality of the weld is an important part of the welding quality control.

[0003] For accurate detection and control of weld quality, there are fewer mature methods and devices that can be used at present, and the accuracy of the detection results is also controversial. Among them, the OCT weld fusion depth detection device is a relatively mature application that can detect the weld fusion depth in real time online. The detection of the weld fusion depth can improve the detection efficiency and accuracy to a certain extent, reduce the number of quality inspectors, improve production efficiency and quality, and reduce labor costs and huge losses caused by the use of substandard products.

[0004] However, the OCT weld fusion depth detection device has only been industrialized in recent years and has not yet reached a fully mature level, and there are still many engineering problems to be solved. For OCT weld fusion depth detection, it is necessary to ensure that the detection beam can accurately enter the "keyhole" (i.e. the welding keyhole) formed by the material welding of the machining beam, and it is very difficult to ensure the position of the detection beam. At present, the control of the position of the detection beam is mostly to set and adjust the relative position of the detection beam and the machining beam before welding starts, and the relative position is kept unchanged during the welding process. This method can meet the application in straight welds and non-swing welding scenes to a certain extent, but its application scenarios are too limited. Moreover, for the existing laser welding equipment, it is difficult to completely ensure that the detection beam and the machining beam are coaxial from the field mirror of the equipment. There is already a distance value between the exit positions of the two beams in the field mirror, and the machining beam is not processed in a vertical incidence manner. This results in an uncertain distance between the two beams when they reach the workpiece surface, that is, there is a significant "travel difference". The existence of the "travel difference" makes it difficult for the detection beam to accurately enter the welding keyhole, so that the welding depth cannot be accurately measured, affecting the accurate judgment of the welding quality. SUMMARY

[0005] In view of one or more of the above defects or improvement needs of the prior art, the present application provides an OCT molten depth detection beam position correction method and welding method for flying welding, which can realize automatic compensation correction of the OCT molten depth detection beam position in the flying laser welding process of a galvanometer scanner, ensure that the position of the detection beam irradiated on the workpiece always corresponds to the welding keyhole, and thus accurately complete real-time detection of the molten depth in the laser welding process.

[0006] To achieve the above object, in one aspect of the present application, an OCT molten depth detection beam position correction method for flying welding is provided, which comprises the following steps: S1: determining the welding path and flying welding process of a workpiece to be welded; S2: converting the welding track to convert the flying welding track into a static welding track; S3: selecting a plurality of static welding points on the static welding track and performing static welding tests to obtain detection beam position compensation coordinates of each static welding point; S4: obtaining detection beam position correction coordinates of corresponding flying welding points on the flying welding track according to the detection beam position compensation coordinates of each static welding point on the static welding track obtained in S3; S5: fitting and analyzing each position correction coordinate to obtain a formula (f(x, y)) conforming to a rule, x f ( x ), y f ( y ) and forming a position correction file of the detection beam based on the formula, thereby completing the position correction of the OCT molten depth detection beam in flying welding.

[0007] As a further improvement of the present application, in S2, the process of converting the flying welding track into a static welding track is as follows: First, the exit position, exit angle and optical path length of the machining beam at each welding point are determined according to the flying welding process and the flying welding track; the exit position of the machining beam at each welding point is translated to the same point, and the static welding track during static welding is drawn according to the action position of the machining beam according to the sequence of the welding points.

[0008] As a further improvement of the present application, in S3, i static welding points are uniformly selected on the static welding track as research objects, and the coordinates in the machining plane rectangular coordinate system are (X i , Y i ), i is an integer; Through the welding test, the specific keyhole position of the i static welding points is accurately found out, and the relative coordinate values of each keyhole relative to the corresponding static welding point are obtained (X x i , y ​​i The relative coordinate value is the position compensation coordinate of the corresponding detection beam.

[0009] As a further improvement of the present invention, relative coordinate values ​​( x i , y i The coordinate system is determined by constructing a compensation coordinate system with its corresponding static weld point as the origin. The horizontal and vertical axes of this compensation coordinate system are parallel to the horizontal and vertical axes of the plane rectangular coordinate system, respectively.

[0010] As a further improvement of the present invention, in S4, the position correction coordinates and the position compensation coordinates are located on the corresponding weld seam trajectories. By combining the distance between the position compensation coordinates and the corresponding static weld points and the flying weld seam trajectory, the position correction coordinates on the flying weld seam trajectory are calculated.

[0011] As a further improvement to the present invention, the formula obtained corresponding to S5 is ( x = f ( x ), y = f ( y The following verification process was also conducted: Select several flight weld point coordinates on the flight weld trajectory, and according to the formula ( x = f ( x ), y = f ( y The positional correction coordinates of each weld point are calculated. Based on the selected flight weld point coordinates, determine the corresponding static weld point coordinates on the static weld trajectory, and conduct welding tests for each static weld point coordinate to measure the position compensation coordinates corresponding to each static weld point coordinate. The position compensation coordinates of each position are converted into the position correction coordinates of the corresponding weld point detection beam on the flight weld trajectory according to S4; the converted position correction coordinates are then compared with those according to the formula ( x = f ( x ), y = f ( y The calculated position correction coordinates are compared to verify the formula (). x = f ( x ), y = f ( y The accuracy of )).

[0012] As a further improvement to the present invention, when formula ( x =f x y f y combining the converted position correction coordinates with the fitting formula; performing the verification and correction processes cyclically until the verification result of the formula (x, y) indicates that it is accurate. x f x y f y

[0013] Another aspect of the present application also provides a galvanometer scanning laser welding method for flight welding, which comprises the OCT molten depth detection light beam position correction method for flight welding, and further comprises the following steps: S6: performing welding control of the machining light beam according to the welding process determined in S1, and determining the working position of the detection light beam relative to the machining light beam according to the position correction file determined in S5, performing laser welding of each weld seam track, and simultaneously completing molten depth detection of each weld point.

[0014] The above improved technical features can be combined with each other as long as they do not conflict with each other.

[0015] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following beneficial effects: (1) The OCT molten depth detection light beam position correction method for flight welding in the present application, based on the determination of the flight welding process and the flight weld seam track, converts the flight weld seam track into a static weld seam track, then obtains static weld points on the static weld seam track to perform static welding test, obtains the detection light beam position compensation coordinates of each static weld point, and converts the position compensation coordinates to obtain the detection light beam position correction coordinates of the corresponding flight weld point on the flight weld seam track, and then fits each position correction coordinate to obtain the position correction file of the detection light beam in flight welding, thereby ensuring the accuracy of OCT molten depth detection in flight welding and improving the flight welding quality of the workpiece.

[0016] (2) The OCT molten depth detection light beam position correction method for flight welding in the present application further simplifies the acquisition process of the position compensation coordinates and the position correction coordinates by optimally designing the conversion process of the flight weld seam track and the static weld seam track and the determination process of the position compensation coordinates on the static weld seam track, improves the efficiency of acquiring the position compensation coordinates and the position correction coordinates, and ensures the accuracy of acquiring the position correction coordinates.

[0017] ​​​​​​​​​​​(3) The OCT penetration depth detection beam position correction method for flying welding in this invention has optimized the verification and correction methods of the detection beam position correction formula, which can further ensure the accuracy of OCT penetration depth detection beam position correction, improve the precision of workpiece flying welding, reduce the defect rate of workpiece welding, and save costs.

[0018] (4) The laser welding method for flying welding in this invention uses a beam position correction method to correct the relative position between the OCT melt depth detection beam and the processing beam during the galvanometer scanning flying laser welding process, so as to ensure that the detection beam can be accurately injected into the keyhole of the weld point during the flying welding process, and to ensure the accuracy of the detection beam in melting depth detection, thereby ensuring the precision of the galvanometer scanning flying welding process and improving the welding quality and efficiency of the workpiece.

[0019] (5) The OCT penetration depth detection beam position correction method for flying welding in this invention has simple steps and convenient operation. It can accurately realize the compensation and correction of the detection beam position relative to the processing beam position during flying welding, providing conditions for accurate control of the detection beam position during flying welding, realizing accurate measurement of laser welding penetration depth during flying welding, ensuring the quality of workpiece flying welding, improving workpiece processing efficiency and quality, and having good economic benefits. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating the OCT weld depth detection beam position correction method for flying welding in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the conversion of a flight welding trajectory into a static welding trajectory in an embodiment of the present invention; Figure 3 This is a schematic diagram of the flight welding process of the galvanometer scanning flying laser welding equipment in an embodiment of the present invention; Figure 4 This is a schematic diagram of the stroke difference between the detection beam and the processing beam at different exit angles in the static welding mode of this invention embodiment; Figure 5 This is a schematic diagram illustrating the positional differences between the processing beam and the detection beam at different locations along the weld trajectory in an embodiment of the present invention; In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. Static welding start beam; 2. Static welding end beam; 3. Weld trajectory; 4. Theoretical laser exit point; 5. Flying welding start beam; 6. Flying welding end beam; 7. Laser exit point trajectory; 8. Conversion end beam; 9. Conversion start beam; 10. Galvanometer scanning laser welding head; 11. Second processing beam; 12. Second detection beam; 13. Processing light exit point; 14. Detection light exit point; 15. Workpiece to be welded; 16. First detection beam; 17. First processing beam; 18. Test weld trajectory; 19. First weld point; 20. Second weld point; 21. First detection light irradiation point; 22. Second detection light irradiation point; 23. Processing coordinate system Y-axis; 24. Processing coordinate system X-axis. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] In the description of this invention, it should be understood that, unless otherwise expressly specified and limited, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] Example: For the OCT penetration depth detection beam position correction method for flying welding in the preferred embodiment of the present invention, its main application scenario is the galvanometer scanning flying laser welding process, especially the application scenario where it is difficult to ensure coaxiality between the output detection beam and the processing beam of the galvanometer scanning flying laser welding equipment.

[0028] Please see Figure 4 For the galvanometer scanning laser welding head 10, it integrates a detection optical path and a processing optical path, which can respectively transmit and scan the detection beam and the processing beam.

[0029] It should be noted that the "flying welding" described in the preferred embodiment corresponds to "static welding". Static welding refers to the welding process in which the workpiece 15 to be welded and the galvanometer scanning laser welding head 10 are relatively stationary (this does not mean that the irradiation positions of the processing beam and the detection beam do not change; the processing position of the processing beam can be controlled by the galvanometer module inside the galvanometer scanning laser welding head 10 for scanning welding). Of course, the galvanometer scanning laser welding head 10 can also be displaced to achieve alignment with different weld seams, thereby realizing the scanning processing of different weld seams.

[0030] For example, in Figure 2In the illustrated form, the weld seam trajectories 3 to be welded are three lines spaced apart in the s direction, namely ab, cd, and ef. Corresponding to the welding of these three weld seam trajectories 3, there are three theoretical laser emission points 4, namely O, O1, and O2. By moving the welding head to these three theoretical laser emission points 4, welding of each weld seam trajectory 3 can be performed separately. For the welding of each weld seam trajectory 3, a beam angle θ is formed between its static welding start beam 1 and static welding end beam 2. By controlling the processing beam to scan within the beam angle θ range, the welding of the corresponding weld seam trajectory 3 can be completed. After completing the welding of one weld seam trajectory 3, by controlling the translational movement of the welding head, the welding head can be switched to different theoretical laser emission points 4, thereby completing the welding of different weld seam trajectories 3.

[0031] In contrast, "flying welding" refers to a vector v that moves relative to the workpiece 15 and the galvanometer scanning laser welding head 10 during the welding process.

[0032] For example, corresponding to Figure 2 The three weld seam trajectories 3 (ab, cd, ef) shown are processed using a flying welding method, as shown in Figure 3. In this method, the welding head moves continuously in the v direction, and its laser emission points are no longer three spaced points, but form a continuous laser emission point trajectory 7, i.e., QQ3. During the flight of the welding head, the welding of the three weld seam trajectories 3 is completed. At this time, two points, Q1 and Q2, are formed on the laser emission point trajectory 7 between two adjacent weld seam trajectories 3. These two points correspond to the end position of the previous weld seam trajectory 3 and the start position of the next weld seam trajectory 3, respectively. The welding head moves continuously within the intervals of QQ1, Q1Q2, and Q2Q3. The flying welding start beam 5 and the flying welding end beam 6 correspond to the two ends of each weld seam trajectory 3, respectively. By utilizing the flight control of the welding head, the scanning welding of each weld seam trajectory 3 can be completed separately.

[0033] Compared to static scanning welding, flying welding can minimize laser downtime and eliminate idle time of the galvanometer welding head.

[0034] Furthermore, during laser welding, due to the keyhole effect, the keyhole position is always located a certain distance behind the position of the processing beam. The detection of the penetration depth requires ensuring that the detection beam is stably injected into the keyhole. Therefore, the position of the detection beam needs to be controlled behind the processing beam.

[0035] More specifically, in order to fully utilize the advantages of flying laser welding, the flight speed is usually set to the maximum feasible speed during galvanometer scanning laser welding. This effectively enlarges the weld size to cover the entire effective processing area of ​​the galvanometer scanning laser welding head 10. Since the distance from different areas within the processing area to the galvanometer scanning laser welding head 10 varies, a so-called "optical path difference" will occur when scanning and processing different parts. It is precisely because of the existence of the "optical path difference" that the processing quality of the workpiece 15 to be welded will be significantly affected.

[0036] Furthermore, due to the difference in wavelength between the detection beam and the processing beam, their refractive indices will also differ when passing through the same lens. This results in different exit points and exit angles for the detection beam and the processing beam after passing through the field lens of the galvanometer scanning laser welding head 10. Therefore, even if the detection beam and the processing beam are coaxially coupled when they enter the galvanometer scanning laser welding head 10, there may still be a certain distance between the exit points of the two beams exiting from the field lens, thus increasing the impact of the "optical path difference".

[0037] For example, in Figure 4 In the case shown, the detection light emission point 14 and the processing light emission point 13 are different, and there is a difference between them. Figure 2 The distance D shown is given. At this time, two welding points A and B are selected on the workpiece 15 to be welded. The angles between the processing beams (i.e., the first processing beam 17 and the second processing beam 11) corresponding to the two welding points and the central axis of the welding head are different (the angle corresponding to point A is significantly larger). Therefore, the distances between the detection points of the first detection beam 16 and the second detection beam 12 emitted from the detection light exit point 14 corresponding to points A and B, and the distances between these detection points and the processing points corresponding to points A and B, are different. Figure 2 In the equations d1 and d2, it is clear that d1 > d2 > D, where D is the distance between the detection light emission point 14 and the processing light emission point 13.

[0038] Obviously, for points A and B mentioned above, the optical path of the processing beam for point A is greater than that for point B. It is precisely because of the change in the optical path of the processing beam that the optical path difference between the detection beam and the corresponding processing beam will also be significantly different. The greater the optical path of the two beams, the more divergent the beams will be, that is, the greater the distance between them (i.e., d1 > d2). The difference between the distance between the two beams and the distance between the exit points of the two beams is also greater (i.e., d1 - D is greater than d2 - D).

[0039] The difference in the exit points of the detection beam and the processing beam leads to variations in the exit angle (relative to the central axis of the weld joint) of the processing beam when scanning different weld joints. Furthermore, there are deviations in the exit angle and optical path length between the detection beam and the processing beam for the same weld joint. This difference causes the distance between the actual points of action of the detection beam and the processing beam to constantly change. In practice, the greater the optical path length of the two beams, the more divergent they become, and the larger the distance between them. Figure 4 As shown in the image.

[0040] It is precisely because of the aforementioned "optical path difference" that the OCT penetration depth detection beam of the galvanometer scanning laser welding head 10 cannot be accurately injected into the keyhole of the molten pool formed by the processing beam during actual operation, thus making it impossible to accurately measure the penetration depth of each weld point keyhole.

[0041] Accordingly, the OCT penetration depth detection beam position correction method for flying welding in the preferred embodiment is proposed to address the above-mentioned problems. Its design principle can be regarded as follows: before the batch flying welding of the workpiece 15 to be welded, the penetration depth detection correction is performed on the welding process of the workpiece 15 to be welded during the flying welding process to obtain the position correction file of the detection beam during the flying welding process. By correcting and compensating the position of the detection beam during the flying welding process of each weld point, it is ensured that the detection position of the detection beam at each weld point can be aligned with the keyhole formed by the processing beam, thereby realizing the accuracy of OCT penetration depth detection of the workpiece 15 to be welded during the flying welding process.

[0042] Specifically, in the preferred embodiment, the OCT penetration depth detection beam position correction method for flying welding includes the following process: S1: Determine the welding path and flight welding process for the workpiece 15 to be welded; In actual setup, according to the requirements of the specific project, the process parameters related to the welding path are set according to the state of the workpiece to be welded during the welding production process to ensure that they are consistent with the production state. Depending on the actual requirements, the welding path may contain one weld track or multiple weld tracks spaced apart from each other. This is related to the processing requirements of the workpiece 15 to be welded, and will not be elaborated here.

[0043] Obviously, in specific operations, it is necessary to determine the process parameters related to each weld trajectory. In a preferred embodiment, the process parameters related to the weld trajectory include the welding start point, end point, and the position distribution of the weld within the processing area of ​​the galvanometer scanning laser welding head 10; thereafter, laser welding process experiments are carried out based on the aforementioned conditions to solidify the welding process during production.

[0044] In actual operation, the welding process can be determined according to the specific welding requirements of the workpiece and the weld seam. It includes at least the necessary welding parameters required for welding. In a preferred embodiment, the welding parameters include the focused spot diameter of the processing laser, the laser power, the welding speed (scanning speed and translation rate), the incident angle, etc.

[0045] In addition, if the laser processing requires oscillating welding during the welding process, the welding parameters also include the oscillation parameters of the laser processing, such as the oscillation pattern, oscillation amplitude, and oscillation frequency.

[0046] S2: Convert the welding trajectory, transforming the flying weld trajectory into a static weld trajectory; The reason for converting the weld trajectory is to make it easier to obtain the keyhole position coordinates of each weld point on the weld trajectory during the flight welding process.

[0047] In actual operation, the exit position, exit angle and optical path length of the processing beam at each weld point are first determined according to the flight welding process and the flight weld trajectory. The exit position of the processing beam at each weld point is translated and transformed to the same point. The static weld trajectory during static welding is drawn according to the order of the weld points and the position of action of the processing beam.

[0048] It is not difficult to understand that after the transformation is completed, the continuous laser emission point trajectory 7 formed during the flight welding process is transformed into a theoretical laser emission point 4.

[0049] by Figure 3 The conversion of the flight weld trajectory (cd) in the example is shown below, where the flight welding start beam 5 and flight welding end beam 6 during flight welding are respectively as follows: Figure 3 As shown, the angles between the two beams and the vertical direction are -γ and γ, respectively. Through the aforementioned trajectory conversion process, the flying weld trajectory cd can be correspondingly converted into the static weld trajectory PQ1. For the static weld trajectory PQ1, the optical path and exit angle of the conversion starting beam 9 are the same as those of the flying welding starting beam 5. At this time, for the conversion starting beam 9, the distance between its detection beam and processing beam can directly correspond to the distance between the detection beam and processing beam of the flying welding starting beam 5; the same applies to the conversion ending beam 8. After the conversion is completed, the angle α between the conversion ending beam 8 and the conversion starting beam 9 is 2γ, which is equal to the sum of the angles between the flying welding starting beam 5 and the flying welding ending beam 6 and the vertical direction (the central axis of the welding head).

[0050] Furthermore, it is easy to see that after the conversion, the trajectory direction of static welding is opposite to the trajectory direction of flight welding before the conversion, that is, in Figure 3 In the process, the converted static welding is performed in the -v direction.

[0051] S3: Select multiple static weld points on the static weld trajectory and perform static welding tests to obtain the detection beam position compensation coordinates of each static weld point on the static weld trajectory. Specifically, i static weld points are uniformly selected as the research object on the static weld trajectory. The coordinates of these static weld points in the rectangular coordinate system of the processing plane of the galvanometer scanning laser welding head 10 are (X... i Y i ), where i is an integer.

[0052] For example, in such Figure 5 In the preferred embodiment shown, the rectangular coordinate system in the processing plane includes an orthogonally set processing coordinate system X-axis 24 and a processing coordinate system Y-axis 23. The research object can be further preferably the first weld point 19 (weld point M) and the second weld point 20 (weld point N) on the test weld trajectory 18.

[0053] More specifically, the origin of the aforementioned Cartesian coordinate system is the center point of the processing area of ​​the galvanometer scanning laser welding head 10. Through welding experiments, the specific keyhole positions of these i weld points are accurately determined, and the relative coordinate values ​​of each keyhole relative to the corresponding static weld point are obtained. x i , y i The relative coordinate value is the position compensation coordinate of the corresponding detection beam.

[0054] It should be noted that the relative coordinate values ​​( x i , y i The coordinate system is determined by constructing a compensation coordinate system with its corresponding static weld point as the origin. The horizontal and vertical axes of this compensation coordinate system are parallel to the horizontal and vertical axes of the Cartesian coordinate system, respectively. In actual operation, the position of each static weld point actually refers to the corresponding point of action of the processing beam on the weld trajectory.

[0055] S4: Based on the position compensation coordinates of the detection beams of each static weld point on the static weld trajectory obtained in S3, obtain the position correction coordinates of the detection beams of the corresponding flying weld points on the flying weld trajectory; Specifically, for the converted static weld trajectory, each weld point on its trajectory is set to correspond to the weld point on the flying weld trajectory. Based on the acquisition of the position compensation coordinates of the detection beam of each weld point on the static weld trajectory, the relative positional relationship between the action point of the detection beam of each weld point and the action point of the processing beam can be obtained. The above relative positional relationship can be directly replaced on the corresponding weld point on the flying weld trajectory.

[0056] Since the processing direction of the converted static weld trajectory is opposite to that of the flying weld trajectory, when converting the relative position relationship, it is necessary to consider the processing direction of the processing beam at the corresponding weld point to ensure that the position correction coordinates are located behind the processing direction of the processing beam.

[0057] In a preferred embodiment, the detection beam is preferably positioned on the weld trajectory behind the processing direction of the processing beam, meaning the position correction coordinates and position compensation coordinates are located on the corresponding weld trajectories. By combining the distance between the position compensation coordinates and the corresponding static weld point, as well as the flying weld trajectory, the position correction coordinates on the flying weld trajectory can be directly calculated.

[0058] For example, in such Figure 5 In the preferred embodiment shown, for the first weld point 19 (weld point M) on the weld track, the position compensation coordinates of its detection beam correspond to the coordinates of the first detection light irradiation point 21 in the plane rectangular coordinate system X1Y1; correspondingly, for the second weld point 20 (weld point N) on the weld track, the position compensation coordinates of its detection beam correspond to the coordinates of the second detection light irradiation point 22 in the plane rectangular coordinate system X2Y2.

[0059] S5: Perform fitting analysis on the corrected coordinates at each position to obtain a formula that conforms to the rule ( x = f ( x ), y = f ( y Based on this, a position correction file for the detection beam is generated, and the position correction of the OCT penetration detection beam under flight welding is completed.

[0060] In practice, after obtaining the aforementioned formula ( x = f ( x ), y = f ( y After that, its accuracy can be verified. The preferred verification process is as follows: Select several flight weld point coordinates on the flight weld trajectory, and according to the formula ( x = f ( x ), y = f ( y The positional correction coordinates of each weld point are calculated. Based on the selected flight weld point coordinates, determine the corresponding static weld point coordinates on the static weld trajectory, and conduct welding tests for each static weld point coordinate to measure the position compensation coordinates corresponding to each static weld point coordinate. The position compensation coordinates of each position are converted into the position correction coordinates of the corresponding weld point detection beam on the flight weld trajectory according to S4; the converted position correction coordinates are then compared with those according to the formula ( x = f ( x ), y = f ( y The calculated position correction coordinates are compared to verify the formula (). x = f ( x ), y = f ( y The accuracy of )).

[0061] If the verification results show that formula ( x = f ( x ), y = f ( y If the formula is not accurate enough, then combine it with the previously converted position correction coordinates to correct the fitting formula; repeat the verification and correction process until the formula is correct. x = f ( x ), y = f ( y The accuracy of the data meets the standards.

[0062] Based on the aforementioned position correction process of the OCT penetration depth detection beam, the motion parameters of the detection beam corresponding to each weld point during the flight welding process can be accurately obtained. This enables accurate detection of penetration depth during the galvanometer scanning laser welding process and the laser processing process in the flight welding state.

[0063] As another aspect of the preferred embodiment, a laser welding method based on the aforementioned OCT penetration depth detection beam position correction method is also provided, which includes the aforementioned steps S1 to S5, and further includes the following process: S6: Control the welding of the processing beam according to the welding process determined in S1, and determine the working position of the detection beam relative to the processing beam according to the position correction document determined in S5. Perform laser welding of each weld trajectory and simultaneously complete the penetration depth detection of each weld point.

[0064] It is understandable that the aforementioned position correction file cannot be universally applied to different workpieces 15 to be welded, galvanometer scanning laser welding heads 10, or different weld trajectories and welding parameters. It needs to be specifically determined for each application scenario. Once determined, batch welding of workpieces 15 to be welded under the same scenario can be completed.

[0065] The OCT penetration depth detection beam position correction method for flying welding in this invention is simple in steps and convenient in operation. It can accurately compensate and correct the position of the detection beam relative to the position of the processing beam during flying welding, providing conditions for accurate control of the detection beam position during flying welding, realizing accurate measurement of laser welding penetration depth during flying welding, ensuring the quality of flying welding of workpieces, improving the processing efficiency and quality of workpieces, and having good economic benefits.

[0066] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An OCT melt depth detection beam position correction method for in-flight welding, characterized by, Comprising the following steps: S1: determining the welding path of the workpiece to be welded and the flight welding process; S2: converting the welding track, converting the flight welding track into a static welding track; S3: selecting a plurality of static welding points on the static welding track and performing a static welding test to obtain the detection beam position compensation coordinates of each static welding point; S4: obtaining the detection beam position correction coordinates of the corresponding flight welding point on the flight welding track according to the detection beam position compensation coordinates of each static welding point on the static welding track obtained in S3; S5: fitting analysis is performed on the corrected coordinates of each position to obtain a formula conforming to the law x = f ( x ), y = f ( y )), and based on this, a position correction file of the detection beam is formed, and the position correction of the OCT fusion depth detection beam in the flying welding is completed.

2. The OCT penetration depth detection beam position correction method for flight welding according to claim 1, characterized by, In S2, the flight welding track is converted into a static welding track as follows: First, determine the exit position, exit angle and optical path length of the machining beam at each welding point according to the flight welding process and the flight welding track; translate the machining beam exit position of each welding point to the same point, and draw the static welding track during static welding according to the action position of the machining beam according to the sequence of the welding points.

3. The OCT penetration depth detection beam position correction method for flight welding according to claim 1 or 2, characterized by, In S3, i static welding points are evenly selected on the static welding seam trajectory as the research objects, and the coordinates in the machining plane rectangular coordinate system are (X i , Y i ), i is an integer; Through the welding test, the specific spoon hole positions of the i static welding points are accurately found out, and the relative coordinate values of each spoon hole relative to the corresponding static welding point are obtained x i , y i ), which is the position compensation coordinate of the corresponding detection light beam.

4. The OCT penetration depth detection beam position correction method for flight welding according to claim 3, characterized by, Relative coordinate values ​​( x i , y i The coordinate system is determined by constructing a compensation coordinate system with its corresponding static weld point as the origin. The horizontal and vertical axes of this compensation coordinate system are parallel to the horizontal and vertical axes of the plane rectangular coordinate system, respectively.

5. The OCT penetration depth detection beam position correction method for flight welding according to claim 1 or 2 or 4, characterized by, In S4, the position correction coordinates and the position compensation coordinates are located on the corresponding welding track, and the position correction coordinates on the flight welding track are calculated by combining the position compensation coordinates, the corresponding static welding points and the flight welding track.

6. The OCT penetration depth detection beam position correction method for flight welding according to claim 1 or 2 or 4, characterized by, The formula obtained in S5 is x = f ( x ), y = f ( y ) and the following verification procedure is also performed: A plurality of flying welding point coordinates are selected on the flying welding seam track, and position correction coordinates of each welding point are calculated according to formulas (1) x = f ( x ), y = f ( y )) According to the selected flight welding point coordinates, the static welding point coordinates corresponding to the static welding track are determined, and welding tests are performed for each static welding point coordinate to measure the position compensation coordinates corresponding to each static welding point coordinate; The position compensation coordinates are converted into position correction coordinates of the corresponding detection light beams on the welding spot of the flight welding track according to S4; the converted position correction coordinates are compared with the position correction coordinates calculated according to formulae x = f ( x ), y = f ( y )) to verify the accuracy of formulae x = f ( x ), y = f ( y ) 7. The OCT weld penetration detection beam position correction method for flight welding according to claim 6, wherein, When the verification result of the formula ( x = f ( x ), y = f ( y )) shows that it is inaccurate, the correction process of the formula is also included. The converted position correction coordinates are corrected by a correction fitting formula; the verification and correction process is repeated until the verification result of the formula (x, y) is accurate. x = f ( x ), y = f ( y )) is accurate.

8. A galvanometer scanning laser welding method for flight welding, comprising the OCT melt depth detection beam position correction method for flight welding according to any one of claims 1 to 7, characterized in that, Further comprising the following steps: S6: welding control of the machining beam according to the welding process determined in S1, and determining the working position of the detection beam relative to the machining beam according to the position correction file determined in S5, laser welding of each welding track, and at the same time completing the penetration detection of each welding point.

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