WO2024256345A1 - Computer-assisted method for aligning a working optical unit, measuring assembly, and production system - Google Patents

Abstract

The invention relates to a computer-assisted method (10) for aligning a working optical unit (12) of a laser working machine (14) to a contact joint (16) of two workpieces (18, 20) of a workpiece assembly (22; 22a-c) which are to be joined, comprising the method steps of: a) positioning (24) a sensor (26) of a measuring system (28) at the contact joint (16) in a predefined working position of the working optical unit (12) by aligning the sensor (26) to a predefined working coordinate (36) of the workpiece assembly (22; 22a-c); b) creating (38) at least one first surface profile (40; 40a-c) by scanning a surface (42) of the workpiece assembly (22; 22a-c) in at least one first measurement plane (44; 44a-c) and creating at least one second surface profile (50; 50a-c) by scanning the surface (42) of the workpiece assembly (22; 22a-c) in at least one second measurement plane (52; 52a-c); wherein the second measurement plane (52; 52a-c) is oriented transversely or perpendicularly to the first measurement plane (44; 44a-c); c) ascertaining (54) at least one first characteristic profile change (56) in the at least one first surface profile (40; 40a-c) and at least one second characteristic profile change (58) in the at least one second surface profile (50; 50a-c); d) determining (60) at least one target working coordinate (62) according to the at least one first profile change (56) and the at least one second profile change (58). The invention further relates to a measuring assembly (70; 70a-c) and to a production system (64).

Description

Computer-aided method for aligning a processing optics, measuring arrangement and manufacturing system

The invention relates to a computer-aided method for aligning a processing optics of a laser processing machine to a contact joint of two workpieces to be joined.

The invention also relates to a measuring arrangement for carrying out the computer-aided method and to a manufacturing system with a laser processing machine and such a measuring arrangement.

Laser processing machines are used to process workpieces using a laser beam and are typically used for joining, welding, separating, cutting and/or for processing a workpiece surface.

DE 10 2014 113 283 A1 describes such a device for remote laser processing of a workpiece using a processing laser beam. The device comprises a sensor unit with an optical sensor for recording analysis data during the processing process.

When creating welded joints on metal workpieces using laser processing machines, a processing laser is directed at a connection point on the workpieces to be joined using the processing optics of the laser processing machine, which leads to a local melting of the workpieces. The quality of the connection depends crucially on the processing optics of the laser processing machine being positioned as precisely as possible relative to the workpieces to be joined.

However, the positioning of the processing optics relative to the workpieces to be joined is generally carried out by means of a pre-programmed processing path that is stored in a control unit of the laser processing machine and is based on an assumed position of the workpieces to be joined. However, when the workpieces are fixed before the welded joint is created, the workpieces may shift, which changes the position and shape of the connection point or contact joint. In addition, workpiece tolerances can lead to a change in the contact joint. Particularly when industrial robots are used, a change in the position of the laser processing machine relative to the workpieces to be joined can also result from the low absolute accuracy of the industrial robot itself.

As a result, a welded joint is formed inaccurately or out of place, which leads to defects in the weld seam quality or, in extreme cases, to a faulty or incomplete weld seam. In addition, a shift in the workpieces can lead to the laser beam being directed past the workpieces into the surrounding area during processing, which can cause damage to the laser processing machine and compromise safety.

In order to be able to take into account a change in the contact joint, various methods and devices for checking the surface of the workpieces to be joined are known from the state of the art.

DE 102017010055 A1 relates to a measuring device for monitoring a laser welding process. Using optical coherence tomography, a processing path of the laser beam processing machine on the workpiece surface can be detected and the geometry of the processing path can be determined.

US 20220016776 A1 describes a system and method for real-time feedback and dynamic adjustment of a welding robot, using a sensor to scan the workpiece to be processed. In summary, the formation of a high-quality and precise weld joint requires a particularly high level of accuracy in the correct positioning of the processing optics relative to the workpieces to be joined. Even small deviations can lead to a significant

A satisfactory solution to the aforementioned problems is not known from the state of the art, which is why, among other things, the time-consuming control of a predetermined position of the weld seam to be formed by a machine operator is necessary.

task of the invention

The invention is based on the object of specifying a method and a device in which an adaptation of processing coordinates is made possible taking into account an actual position of the contact joint for producing a welded connection.

Description of the Invention

This object is achieved according to the invention by a computer-aided method according to claim 1. The object is also achieved by a measuring arrangement according to claim 13 and a manufacturing system according to claim 14. The subclaims relate to preferred embodiments of the invention.

According to the invention, a computer-aided method is proposed. In other words, the method is carried out at least partially by computer implementation, or using at least one computer.

The method is suitable for aligning a processing optics of a laser processing machine. In other words, the method is designed at least for determining machine settings relating to the alignment of the processing optics, wherein the determined machine settings for example, can be adjusted manually by an operator on the laser processing machine. Preferably, the method is designed for, in particular, automatic, alignment of the processing optics on a laser processing machine.

According to the invention, the processing optics are aligned to a contact joint between the workpieces to be joined. Typically, the contact joint is formed by two workpieces to be joined. In other words, the workpieces limit the contact joint, in particular transversely to a groove profile of the contact joint.

The contact joint is typically designed to create the welded connection. It can be provided that the workpieces to be joined are fused together at least in sections in the area of the contact joint by the processing laser of the laser processing machine. The contact joint can be designed to accommodate an additional welding material, in particular a welding wire.

The workpieces to be joined form a workpiece arrangement in a position fixed to one another. The method is preferably designed to align a processing optics with a contact joint in an abutting workpiece arrangement.

Alignment can be carried out with respect to a predetermined processing coordinate for joining the workpieces by the laser processing machine.

Typically, the workpieces are joined by the action of a processing laser on several, in particular a large number of, predetermined processing coordinates. The predetermined processing coordinates typically form a predetermined processing path along which the workpieces are to be joined by the laser processing machine. Preferably, the alignment is carried out with respect to a first and/or a last predetermined processing coordinate of the predetermined processing path. This allows the method for determining a workpiece start and/or a workpiece end or a contact joint start and/or a contact joint end.

The method is preferably designed as a pre-joining method (pre-process). In other words, the method is preferably carried out before the workpiece arrangement is processed by the laser processing machine, or the workpieces to be joined are joined. In a special embodiment, the method can be carried out immediately before the joining by the laser processing machine. In particular, the processing optics can be aligned to a predetermined processing coordinate and joining can take place immediately afterwards. This can increase the production speed.

The method according to the invention comprises at least the following method steps:

In a method step a) of the computer-aided method, a sensor of a measuring system is positioned in a predetermined processing position of the processing optics on the contact joint. The sensor is aligned to a predetermined processing coordinate of the workpiece arrangement. In other words, the sensor is moved to a production position of the processing optics and aligned to an area of action of the processing laser on the workpiece arrangement.

A further method step b) of the computer-aided method provides for the creation of at least one first surface profile. The first surface profile is created by scanning a surface of the workpiece arrangement in at least one first measuring plane. The first measuring plane is typically aligned transversely or perpendicularly to the predetermined machining path. In addition, method step b) provides for the creation of at least one second surface profile. The second surface profile is created by scanning the surface of the workpiece arrangement in at least one second measuring plane. According to the invention, the second measuring plane is aligned transversely or perpendicularly to the first measuring plane. The position of the first measuring plane in relation to the second The measuring plane is predetermined, whereby a geometric dependency between the first surface profile and the second surface profile is known.

Preferably, scanning is carried out by measuring a distance between the sensor and several measuring points on the surface of the workpiece arrangement, wherein the measuring points are designed as intersection points between the respective measuring plane and the workpiece arrangement. In other words, the surface can be scanned along a measuring path projected onto the surface by the respective measuring plane. The measuring points are preferably created by deflecting a measuring beam in the respective measuring plane by a predetermined value, e.g. a radian measure, or a predetermined angle. This means that geometric dependencies between the measuring points and thus geometric dependencies in the created surface profile are known.

A further method step c) of the computer-aided method provides for determining at least one first characteristic profile change in the at least one first surface profile. In addition, method step c) provides for determining at least one second characteristic profile change in the at least one second surface profile. In other words, at least one characteristic profile change is determined in each of the surface profiles created.

A characteristic profile change can be understood as an anomaly in the course of the surface profile, for example a depression, an elevation, a kink and/or a discontinuity. It can also be provided that no characteristic profile change is detected in one of the surface profiles. In the absence of a characteristic profile change, for example, a significant shift in the workpieces and/or the absence of a workpiece can be detected. This can prevent damage from the laser processing machine.

The determination of the characteristic profile changes is typically carried out by evaluating the surface profiles. Preferably by geometric analysis of the Surface profiles and determining coordinates for the characteristic profile change within the surface profile.

The evaluation is preferably carried out using graphic image analysis. The evaluation can be carried out in accordance with the embodiments described above and below. The evaluation preferably comprises one or more of the following evaluation steps:

An evaluation step can be carried out, whereby track sections are determined in the respective surface profile. Track sections can typically be read out from the respective surface profile using line recognition. Track sections typically have a constant gradient, a starting point and an end point.

A subsequent evaluation step can provide for the positional relationships between the determined track sections to be determined. As shown, it can be provided that connected track sections are determined. Connected track sections typically indicate a separate workpiece to be joined. A contact joint is typically formed between two separate connected track sections.

In addition, it can be provided that the positional relationship between connected route sections is determined. For example, a discontinuity between gradients of the route sections and the route sections can be determined as a break point.

A further evaluation step can provide for a vertical distance between each characteristic profile change and the predetermined processing coordinate to be determined or calculated. Typically, an average distance is determined or calculated from the vertical distances of the profile changes to the predetermined processing coordinate. A further evaluation step can provide that only a single connected section is determined in one of the surface profiles. The evaluation can provide that the characteristic profile change of the individual connected section is determined as a workpiece end.

A further evaluation step may provide for a vertical distance between the characteristic profile change of the only connected section of the route and the predetermined processing coordinate to be determined or calculated.

In addition, a method step d) of the computer-aided method provides for determining at least one target machining coordinate as a function of the at least one first profile change and the at least one second profile change.

A target processing coordinate can be understood as an optimal processing coordinate of the laser processing machine or the processing optics on the workpiece arrangement. Typically, a target processing coordinate is determined that is centered in the contact joint.

In particular, a first target machining coordinate and/or a last target machining coordinate is determined at a contact joint start or a contact joint end. In other words, a first target machining coordinate or a last target machining coordinate can be set for an area of the workpiece arrangement in which - even with an offset between the workpieces - a contact joint is formed.

When determining the target machining coordinate, the previously determined vertical distances as well as the previously determined mean distances are typically used as a possible adjustment of the predetermined machining coordinate within the respective measuring plane. Alternatively or additionally, when determining the target machining coordinate, the vertical distances can be used as a possible adjustment of the predetermined machining coordinate within the respective measuring plane.

The determination of the target machining coordinate is therefore dependent on the characteristic profile changes.

In summary, the invention proposes a computer-aided method that enables particularly precise determination of an actual position and alignment of workpieces to be joined in a workpiece arrangement or a contact joint between the workpieces. This allows a processing optics of a laser processing machine to be adapted to an actual position of the workpieces particularly quickly and reliably, whereby the weld joint quality can be maintained and the degree of automation of the laser processing machine is increased.

In a preferred embodiment of the computer-aided method, the at least one first measuring plane has a measuring distance, in particular along the at least one second measuring plane, from the predetermined processing coordinate. In other words, the first measuring plane is designed off-center to the predetermined processing coordinate. This allows the surface of the workpiece arrangement to be scanned ahead of and/or behind the predetermined processing coordinate.

Further preferred is an embodiment of the computer-aided method in which at least one further first surface profile is created by scanning the surface of the workpiece arrangement in at least one further first measuring plane. The at least one further first measuring plane is typically formed parallel to the at least one first measuring plane. In other words, the surface is scanned twice along a predetermined machining path relative to the predetermined machining coordinate. This allows two first surface profiles to be created and the characteristic profile changes of the first surface profiles to be compared. In particular, when determining the target machining coordinate, a rotation can be taken into account by means of the predetermined characteristic profile changes of the first surface profiles and using the distance between the first measuring plane and the further first measuring plane.

In a preferred development of the computer-aided method, a target machining path is determined from the at least one first surface profile in method step c). Alternatively or additionally, a target machining path is determined from the at least one first surface profile and the at least one further first surface profile in method step c). Typically, in method step d), at least one, preferably several, particularly preferably a large number of further target machining coordinates are then determined depending on the at least one characteristic profile change along the machining path. This allows the method to be carried out particularly effectively.

Another preferred embodiment of the computer-aided method is one in which at least one further second surface profile is created by scanning the surface of the workpiece arrangement in at least one further second measuring plane. The at least one further second measuring plane is typically formed parallel to the at least one second measuring plane. In other words, the surface is scanned twice transversely or perpendicularly to the predetermined machining path relative to the predetermined machining coordinate. This allows two second surface profiles to be created and the characteristic profile changes of the two second surface profiles to be compared.

In particular, when determining the target machining coordinate, a contact joint start and/or a contact joint end can be taken into account by means of the predetermined characteristic profile changes of the two second surface profiles. In a preferred development of the computer-aided method, several, in particular a large number of, further first surface profiles and/or further second surface profiles are created. The further surface profiles are preferably created by scanning the surface in a corresponding number of further measuring planes. This allows the method to be carried out more robustly.

A further development of the computer-aided method is also preferred in which the first measuring planes and/or the second measuring planes are each formed at the same distance from one another. This allows evaluation and determination of the target processing coordinate to be carried out particularly quickly and easily.

In a preferred embodiment of the computer-aided method, the measuring planes form a rectangular, in particular square, measuring field on the surface of the workpiece arrangement. By forming a measuring field, a representative area of the surface of the workpiece arrangement can be selected for creating the surface profiles. The measuring area delimits the measuring planes. The measuring area preferably has an extension of at least seven millimeters, particularly preferably at least nine millimeters.

In addition, an embodiment of the computer-aided method is preferred in which, in method step c), a contact joint start and/or a contact joint end is determined from the at least one first surface profile and/or from the at least one second surface profile, wherein the target processing coordinate is determined as the contact joint start or the contact joint end.

An embodiment of the computer-aided method is also preferred in which optical coherence tomography is used to carry out the method. The inventors have recognized that the method can be carried out particularly robustly and reliably using optical coherence tomography and/or a 2D scanning deflection system for the measuring beam. A preferred embodiment of the computer-aided method provides that the method steps a) to d) are carried out for several, in particular each, predetermined processing coordinate along a predetermined processing path of the processing optics. This allows a particularly precise alignment of the processing optics along the entire actual contact joint.

In a preferred development of the computer-aided method, the method steps a) to d) are carried out at a constant feed rate of the sensor along the predetermined processing path and/or an adapted processing path. This allows the processing optics to be aligned immediately before the workpieces are joined by the laser processing machine.

The underlying task is also solved by a measuring arrangement.

The measuring arrangement comprises a workpiece arrangement made up of two workpieces. The workpieces are typically arranged in a butt arrangement and form a contact joint.

The measuring arrangement has a measuring system with at least one sensor. Preferably, the measuring system is an OCT (optical coherence tomography) measuring system and the sensor is a measuring arm of the OCT measuring system. The measuring system is set up to carry out the computer-aided method described above and below.

The underlying task is further solved by a manufacturing system.

The manufacturing system comprises a laser processing machine and a measuring arrangement as described above and below.

According to the invention, the sensor of the measuring system is arranged on a processing optics of the laser processing machine. The sensor can in particular be coaxial or laterally offset to the laser processing beam of the laser processing machine.

Further features and advantages of the invention emerge from the description, the claims and the drawing. According to the invention, the features mentioned above and those described below can each be used individually or in groups in any appropriate combination. The embodiments shown and described are not to be understood as an exhaustive list, but rather are exemplary in nature for describing the invention.

Detailed description of the invention and drawing

They show:

Fig. 1: a computer-aided method according to the invention in a schematic representation;

Fig. 2: schematically shows a manufacturing system with a laser processing machine and a workpiece arrangement in a perspective view;

Fig. 3: a first embodiment of a measuring arrangement with a sensor positioned at a contact joint of the workpiece arrangement in a schematic representation;

Fig. 4: a first surface profile of the workpiece arrangement from Fig. 3 in a schematic representation;

Fig. 5: a second surface profile of the workpiece arrangement from Fig. 3 in a schematic representation; Fig. 6: the workpiece arrangement from Fig. 3 with a specific target machining coordinate;

Fig. 7: a second embodiment of a measuring arrangement with the sensor positioned at the contact joint of another workpiece arrangement in a schematic representation;

Fig. 8: a second surface profile of the workpiece arrangement from Fig. 7 in a schematic representation;

Fig. 9: a further second surface profile of the workpiece arrangement from Fig. 7 in a schematic representation;

Fig. 10: the workpiece arrangement from Fig. 7 with a specific target machining coordinate;

Fig. 11: a third embodiment of a measuring arrangement with the sensor positioned at the contact joint of another workpiece arrangement in a schematic representation;

Fig. 12: a first surface profile of the workpiece arrangement from Fig. 11 in a schematic representation;

Fig. 13: another first surface profile of the workpiece arrangement from Fig. 11 in a schematic representation; and

Fig. 14: the workpiece arrangement from Fig. 11 with a specific target machining coordinate and a target machining path.

Fig. 1 shows a computer-aided method 10 according to the invention.

The computer-aided method 10 is explained below with reference to the remaining figures of the drawing. The method 10 is suitable for aligning a processing optics 12 (see Fig. 2) of a laser processing machine 14 (see Fig. 2) to a contact joint 16 (see Fig. 2, 3, 4, 6, 7, 10, 11, 14) of a first workpiece 18 to be joined (see Fig. 2, 3, 6, 7, 10, 11-14) and a second workpiece 20 to be joined (see Fig. 2, 3, 6, 7, 10, 11-14) of a workpiece arrangement 22 (see Fig. 2, 3, 6, 7, 10, 11, 14).

Preferably, the method 10 is designed to align the processing optics 12. In other words, in a preferred embodiment, it can be provided that the method 10 receives access to the processing optics 12 or the laser processing machine 14 in order to align the processing optics 12 and/or the laser processing machine 14. The alignment can be carried out by adapting machine commands in a control device 23 (see Fig. 2) of the laser processing machine 14.

The method 10 comprises at least the following method steps:

In a first method step 24 of the computer-aided method 10, a positioning of a sensor 26 (see Fig. 2) of a measuring system 28 (see Fig. 2) in a predetermined processing position of the processing optics 12 on the contact joint 16 is provided.

In other words, the sensor 26 is positioned such that the location or position and alignment of the sensor 26 corresponds to a predetermined or pre-programmed position of the processing optics 12 during the joining of the workpieces 18, 20 (see Figures 2-14). The sensor 26 is preferably arranged or attached in or to the processing optics 12 of the laser processing machine 14. This allows the sensor 26 to be positioned particularly precisely in the predetermined processing position.

Typically, the workpieces 18, 20 are welded together before joining by the

Laser processing machine 14 initially in a predetermined position in the

Workpiece arrangement 22 is fixed or clamped, whereby a displacement of the Workpieces 18, 20 are prevented. Preferably, the workpieces 18, 20 are arranged in a butt arrangement. However, the method can also be applied to other arrangements, for example corner arrangements, of the workpieces 18, 20.

The workpiece arrangement 22 forms the contact joint 16 along a predetermined connecting section of the workpieces 18, 20. The position of the workpieces 18, 20 to be joined and/or the contact joint 16 is typically entered or pre-programmed in the control device 23 (see Fig. 2) of the laser processing machine 14. The laser processing machine 14 produces a weld joint (not shown) along the contact joint 16 in a joining process (not shown) downstream of the process 10 described here. To produce the weld joint, the processing optics 12 of the laser processing machine 14 are moved parallel to a predetermined processing path 32 (see Figures 2, 3, 6, 7, 10, 11, 13, 14) and the processing laser 34 (see Fig. 2) is directed to one, typically several predetermined processing coordinates 36 (see Figures 2-14). The welded joint can be designed as a weld seam and/or as a spot welded joint.

According to the invention, the sensor 26 is positioned on or in the immediate vicinity of the contact joint 16 in which the weld seam is to be produced and is aligned with one of the predetermined processing coordinates 36 of the predetermined processing path 32. The sensor is preferably aligned with a first or a last predetermined processing coordinate 36 of the predetermined processing path 32.

In a further method step 38, at least one first surface profile 40 (see Figures 2, 4, 12) is created by scanning a surface 42 (see Figure 2) of the workpiece arrangement 22 in at least one first measuring plane 44 (see Figures 2, 3, 4, 7, 11, 12).

The scanning of the surface 42 is preferably carried out by measuring the

Distance between the sensor 26 and several, in particular a plurality of, Measuring points 46 (see Fig. 2) on the surface 42 of the workpiece arrangement 22. For reasons of clarity, only one measuring point 46 is provided with a reference symbol. The measurement is particularly preferably carried out by means of optical coherence tomography, in particular by means of a 2D scanning OCT sensor system.

When the first measuring plane 44 is aligned transversely or perpendicularly to the predetermined processing path 32, both workpieces 18, 20 of the workpiece arrangement 22 can be detected in the measuring plane 44. This enables the processing optics 12 to be precisely aligned, for example to a center point of the contact joint 16.

The measuring plane 44 is typically formed transversely or perpendicularly to the predetermined machining path 32, wherein the actual orientation with respect to the workpiece arrangement 22 results from the deviation of the predetermined machining coordinate 36 and the course of the predetermined machining path 32 to the actual workpiece arrangement 22.

In addition, in method step 38, at least one second surface profile 50 (see Figures 2, 4, 5, 8, 9, 12, 13) is created by scanning the surface 42 of the workpiece arrangement 22 in at least one second measuring plane 52 (see Figures 2, 3, 5, 7, 8, 11). The second measuring plane 52 is aligned transversely or perpendicularly to the first measuring plane 44.

In a further method step 54, a determination of at least one first characteristic profile change 56 (see Figures 2, 4, 12, 13) in the at least one first surface profile 40 is provided.

In addition, in method step 54, a determination of at least one second characteristic profile change 58 (see Figures 5, 8, 9) in the at least one second surface profile 50 is provided.

A characteristic profile change 56, 58 can, for example, be a jump in the

Course of the first surface profile 40 and/or in the course of the second surface profile 50, wherein the jump can be determined, for example, by a change in a measured distance between the sensor 26 and workpiece arrangement 22.

In addition, the computer-aided method 10 comprises a method step 60 in which a determination of at least one target machining coordinate 62 (see Figures 2, 6, 10, 14) is provided as a function of the at least one first profile change 56 and the at least one second profile change 58.

In other words, a predetermined processing coordinate 36 is adapted to an actual workpiece arrangement 22 or an actual contact joint 16. Adapting the predetermined processing coordinate 36 can be done, for example, by changing the coordinates of the predetermined processing coordinate 36. As a result, the processing optics 26 of the laser processing machine 14 are centered in the actually formed contact joint 16. Forming the weld joint in a subsequent joining process can thus be done particularly effectively.

Fig. 2 shows a manufacturing system 64 with a laser processing machine 14 and a workpiece arrangement 22 in a schematic representation.

As shown, the laser processing machine 14 has the measuring system 28. The sensor 26 is, as shown, arranged on the processing optics 12 of the laser processing machine 14. This allows positioning of the sensor 26 in the predetermined processing position of the processing optics 12 to be carried out particularly quickly and easily.

The location, or position and alignment, of the processing optics 12 can be changed by means of an extension arm 66. This allows the processing optics 12 and the sensor 26 to be moved along the predetermined processing path 32.

The measuring system 28 is preferably designed and constructed to carry out optical coherence tomography (OCT). In other words, the measuring system 28 may comprise an optical coherence tomograph. To scan the surface 42, the sensor 26 directs a measuring beam 68 within the measuring plane 44, 52 onto the tool arrangement 22, which is designed to measure a distance between the sensor 26 and the respective measuring point 46 projected onto the surface 42. The measuring beam can be positioned as desired using an integrated 2D scanner, and a change from the measuring plane 44 to the measuring plane 52 can take place without moving the processing optics 12 or the sensor 26.

In a preferred embodiment, the sensor 26 is arranged on the processing optics 12 in such a way that the measuring beam 68 precedes the processing laser 34 along the predetermined processing path 32 during the joining of the workpieces 18, 20. This allows the predetermined processing coordinate 36 to be adjusted immediately before the joining by the laser processing machine 14.

The sensor 26, or the measuring system 28 and the workpiece arrangement 22 form a measuring arrangement 70 as shown.

Fig. 3 showed a measuring arrangement 70a in a schematic representation.

As shown, the sensor 26 is positioned substantially vertically above the predetermined processing coordinate 36 on the contact joint 16 of a workpiece arrangement 22a.

A first measuring plane 44a and a second measuring plane 52a are shown projected onto the surface 42 of the workpiece arrangement 22a. The first measuring plane 44a and the second measuring plane 52a form a measuring field 72 on the surface 42 of the workpiece arrangement 22a. The measuring field 72 is, as shown, rectangular - here square.

The second measuring plane 52a is perpendicular to the first measuring plane 44a.

This allows the detection of profile changes 56 (see Figures 2, 4, 12, 13) from the created surface profiles 40a, 50a (see Figures 4, 5) can be carried out particularly effectively.

As shown, one of the measuring planes 44, 52 - here the measuring plane 52a - can be aligned in the direction of the predetermined machining path 32. Preferably, the other measuring plane 44, 52 - here the measuring plane 44a - is aligned transversely to the predetermined machining path 32. This ensures that the contact joint 16 and/or a workpiece start 74, 76 or a workpiece end (not shown) of the workpieces 18, 20 are detected by the measuring planes 44, 52.

Fig. 4 shows schematically a first surface profile 40a, which was created by scanning the surface 42 of the workpiece arrangement 22a in the measuring plane 44a from Fig. 3.

The surface 42 and the contact joint 16 of the workpiece arrangement 22a can be seen in the surface profile 40a.

By evaluating the surface profile 40, characteristic profile changes 56 can be determined. The profile changes 56 are formed here as edges of the workpieces 18, 20 facing the contact joint 16.

The evaluation is typically carried out using graphic image analysis. The evaluation can be carried out as described in the description and as described in the other figures. The evaluation preferably comprises one or more of the following evaluation steps:

An evaluation step can provide for track sections 78a-d to be determined in the first surface profile 40a. Track sections 78a-d can typically be read out from the first surface profile 40a using line recognition. Track sections 78a-d typically have a constant gradient, a starting point and an end point. A subsequent evaluation step can provide for the positional relationships between the track sections 78a-d to be determined. As shown, it can be provided that connected track sections 78a, 78b and 78c, 78d are determined. Connected track sections 78a, 78b and 78c, 78d each indicate a separate workpiece 18 or 20. A contact joint 16 is typically formed between two separate connected track sections 78a, 78b; 78c, 78d or between the workpieces 18, 20.

In addition, it can be provided that the positional relationship between connected track sections 78a, 78b and 78c, 78d is determined. In this way, a discontinuity between gradients of track sections 78a and 78b and track sections 78c and 78d can be determined as a kink point. A kink point typically represents a characteristic profile change 56.

A further evaluation step can provide that a vertical distance 80a, 80b between each characteristic profile change 56 and the predetermined processing coordinate 36 is determined or calculated. Typically, an average distance 80c is determined or calculated from the vertical distances 80a, 80b of the profile changes 56 to the predetermined processing coordinate 36. The vertical distances 80a, 80b and the average distance 80c can be understood as a possible adaptation of the predetermined processing coordinate 36 within the measuring plane 44a.

Fig. 5 schematically shows a second surface profile 50a, which was created by scanning the surface 42 of the workpiece arrangement 22a in the measuring plane 52a from Fig. 3.

The surface 42 of the workpiece arrangement 22a can be seen in the surface profile 50a. By evaluating the surface profile 50a, at least one characteristic profile change 58 can be determined. The profile change 58 is designed here as an end point of the workpiece 20. An end point can be understood as the workpiece start 76 or the workpiece end.

An evaluation step can be provided whereby track sections 78e, 78f are determined in the arrangement profile 50a. In addition, it can be provided that the positional relationship between the connected track sections 78e, 78f is determined, whereby the characteristic profile change 58 can be determined.

As shown, the track sections 78e and 78f represent a single connected track section 78e, 78f. The evaluation can provide that the characteristic profile change 58 of the individual connected track section 78e, 78f is determined as the end point of the workpiece 20.

A further evaluation step can provide that a vertical distance 80d between the characteristic profile change 58 and the predetermined processing coordinate 36 is determined or calculated. The vertical distance 80d can be understood as a possible adaptation of the predetermined processing coordinate 36 within the measuring plane 52a.

Fig. 6 shows a manufacturing arrangement 82a of the workpiece arrangement 22a from Fig. 3 in a schematic representation.

The target processing coordinate 62 was determined as a function of the profile changes 56, 58 determined from the surface profiles 40a, 50a (see Figures 4, 5). The target processing coordinate 62 is shifted by the average distance 80c (see Figure 4) along the measuring plane 44a (see Figures 3, 4) and by the vertical distance 80d (see Figure 5) along the measuring plane 52a (see Figures 3, 5). The target machining coordinate 62 is thus positioned centrally in the contact joint 16 at the workpiece beginnings 74, 76 of the workpiece arrangement 22a, which enables the formation of a high-quality weld joint.

As shown, determining the target processing coordinate 62 can cause a displacement, in particular a parallel displacement, of the predetermined processing path 32. In other words, several, in particular all, predetermined processing coordinates 36 of a predetermined processing path 32 can be adjusted in accordance with the target processing coordinate 62. This creates a target processing path 84 that further improves the high-quality formation of the welded connection.

Fig. 7 showed a measuring arrangement 70b in a schematic representation.

As shown, the sensor 26 is positioned substantially vertically above the predetermined machining coordinate 36 on the contact joint 16 of a workpiece arrangement 22b.

A first measuring plane 44b and a second measuring plane 52b are shown projected onto the surface 42 of the workpiece arrangement 22b. In addition, as shown, a further second measuring plane 86 is shown projected onto the surface 42.

The second measuring plane 52b is perpendicular to the first measuring plane 44b. The further second measuring plane 86 is parallel to the second measuring plane 52b. The first measuring plane 44b, the second measuring plane 52b and the further second measuring plane 86 form the measuring field 72 on the surface 42 of the workpiece arrangement 22b.

As shown, the second measuring plane 52b is directed towards the surface 42 of the first workpiece 18 and the further measuring plane 86 is directed towards the surface 42 of the second workpiece 20. In other words, the measuring planes 52b and 86 are formed off-center to the predetermined machining coordinate 36, or have a measuring distance of 87. This allows a further range of

Workpiece arrangement 22b can be detected by the measuring planes 52b, 86.

The workpieces 18, 20 of the workpiece arrangement 22b have an offset 88 along the predetermined machining path 32, or workpiece beginnings 74, 76 offset from one another.

Fig. 8 schematically shows a second surface profile 50b which was created by scanning the surface 42 of the workpiece arrangement 22b in the measuring plane 52b from Fig. 7.

By evaluating the surface profile 50b, a characteristic profile change 58 can be determined by determining the track sections 78e, 78f and their positional relationship to one another.

Furthermore, it can be provided that the vertical distance 80d between the characteristic profile changes 58 and the predetermined processing coordinate 36 is determined or calculated.

Fig. 9 schematically shows a further second surface profile 50c, which was created by scanning the surface 42 of the workpiece arrangement 22b in the measuring plane 86 from Fig. 7.

By evaluating the surface profile 50c - analogous to the procedure according to Fig. 8 - a characteristic profile change 58 can be determined by determining the track sections 78e, 78f and their positional relationship to one another.

Furthermore, it can be provided that the vertical distance 80d between the characteristic profile changes 58 and the predetermined processing coordinate 36 is determined or calculated.

Fig. 10 shows a manufacturing arrangement 82b of the workpiece arrangement 22b from Fig. 3 in a schematic representation. Depending on the profile changes 58 determined from the surface profiles 50b (see Fig. 8) and 50c (see Fig. 9), an alignment of the target processing coordinate 62 along the predetermined processing path 32 was determined. The target processing coordinate 62 is shifted by a minimum vertical distance 80d (see Fig. 9) of the vertical distances 80d from Figures 8 and 9 along the further second measuring plane 86 (see Fig. 7). In other words, the target processing coordinate 62 has been adjusted to the workpiece start 76 of the second workpiece 20, or a contact joint start 89 of the contact joint 16. This ensures that a welded connection is only formed in the area of the contact joint 16.

An adjustment of the target machining coordinate 62 along the first measuring plane 44b (see Fig. 7) can be carried out analogously to the procedure described in Fig. 6, wherein a mean distance 80c is determined or calculated according to Fig. 4.

The target machining coordinate 62 is thus positioned centrally in the contact joint 16 at the workpiece beginning 76 of the workpiece arrangement 22a, which enables the formation of a high-quality weld joint.

As shown, determining the target processing coordinate 62 can cause a displacement, in particular a parallel displacement, of the predetermined processing path 32. In other words, several, in particular all, predetermined processing coordinates 36 of a predetermined processing path 32 can be adjusted in accordance with the target processing coordinate 62. This creates the target processing path 84, which further improves the high-quality formation of the welded joint.

Fig. 11 showed a measuring arrangement 70c in a schematic representation.

As shown, the sensor 26 is positioned vertically above the predetermined processing coordinate 36 on the contact joint 16 of a workpiece arrangement 22c. A first measuring plane 44c and a second measuring plane 52c are shown projected onto the surface 42 of the workpiece arrangement 22c. In addition, as shown, a further first measuring plane 90 is shown projected onto the surface 42.

The second measuring plane 52c is formed perpendicular to the first measuring plane 44c. The further first measuring plane 90 is formed parallel to the first measuring plane 44c. The first measuring plane 44c, the second measuring plane 52c and the further first measuring plane 90 form the measuring field 72 on the surface 42 of the workpiece arrangement 22c.

As shown, the first measuring plane 44c and the further first measuring plane 90 are aligned transversely to the predetermined processing path 32 on the surface 42 of the workpieces 18, 20. The measuring planes 44c and 90 are designed off-center to the predetermined processing coordinate 36, or have a measuring distance 91. As a result, a further area of the workpiece arrangement 22c can be detected by the measuring planes 44c, 90.

The workpieces 18, 20 of the workpiece arrangement 22b are designed to be rotated relative to the predetermined machining path 32. In other words, the target machining path 84 is designed to be inclined to the predetermined machining path 32 by a rotation angle 92.

Fig. 12 schematically shows a second surface profile 40c, which was created by scanning the surface 42 of the workpiece arrangement 22c in the measuring plane 44c of Fig. 11.

By evaluating the surface profile 44c, a characteristic profile change 56 can be determined by determining the track sections 78a-d and their positional relationship to one another. Furthermore, it can be provided that the vertical distance 80a, 80b between each characteristic profile change 56 and the predetermined processing coordinate 36 is determined or calculated. Typically, the average distance 80c is determined or calculated from the vertical distances 80a, 80b of the profile changes 56 to the predetermined processing coordinate 36.

Fig. 13 schematically shows a further second surface profile 50c, which was created by scanning the surface 42 of the workpiece arrangement 22c in the measuring plane 90 from Fig. 11.

By evaluating the surface profile 50c, a characteristic profile change 56 can be determined by determining the track sections 78a-d and their positional relationship to one another.

Analogous to Fig. 12, it can be provided that the vertical distances 80a, 80b between each characteristic profile change 56 and the predetermined machining coordinate 36 as well as the mean distance 80c are determined or calculated.

As shown, the mean distance 80c according to Fig. 13 has an orientation that is reversed compared to the mean distance 80c according to Fig. 12 and a different value.

Fig. 14 shows a manufacturing arrangement 82c of the workpiece arrangement 22c from Fig.

11 in a schematic representation.

Depending on the profile changes 56 determined from the surface profiles 40c according to Fig. 12 and 40c according to Fig. 13, an alignment of the target machining coordinate 62 was effected by rotating the predetermined machining path 32 into the target machining path 84.

A twisting can be determined by means of the profile changes 56 of Figures 12, 13 and/or by comparing the mean distances 80c of Figures 12, 13 and Taking into account the distance between the first measuring plane 44c and the further measuring plane 90.

An adjustment of the target machining coordinate 62 along the first measuring plane 44c (see Fig. 11 ) can be carried out analogously to the procedure described according to Fig. 5, wherein an average value between the mean distances 80c is determined or calculated according to Figures 12, 13.

An adjustment of the target machining coordinate 62 along the second measuring plane 52c (see Fig. 11 ) can be carried out analogously to the procedure according to Fig. 6, whereby a vertical distance 80d (see Fig. 6) is determined or calculated.

The target machining coordinate 62 is thus positioned centrally in the contact joint 16 at the workpiece beginnings 74, 76 of the workpiece arrangement 22c. Furthermore, the predetermined machining path 32 is adapted to the actual formation of the contact joint 16 by means of the target machining path 84, which enables the formation of a high-quality welded joint.

list of reference symbols

Computer-aided process Processing optics Laser processing machine Contact joint First workpiece Second workpiece ; 22a-c Workpiece arrangement Control device Process step

sensor

Measuring system predetermined machining path machining laser predetermined machining coordinate process step; 40a-c first surface profile

surface; 44a-c first measuring plane

measuring point; 50a-c second surface profile; 52a-c second measuring plane

Process step , 58 characteristic profile change

process step

target machining coordinate manufacturing system

extension arm measuring beam; 70a-c measuring arrangement Measuring field , 76 Workpiece start af Section ad Distance ac Production arrangement

Target machining path further second measuring plane measuring distance

offset

Contact joint start further first measuring plane measuring distance angle of rotation

Claims

patent claims 1. Computer-aided method (10) for aligning a processing optics (12) of a laser processing machine (14) to a contact joint (16) of two workpieces (18, 20) to be joined in a workpiece arrangement (22; 22a-c), comprising the method steps: a) positioning (24) a sensor (26) of a measuring system (28) in a predetermined processing position of the processing optics (12) at the contact joint (16) by aligning the sensor (26) to a predetermined processing coordinate (36) of the workpiece arrangement (22; 22a-c); b) creating (38) at least one first surface profile (40; 40a-c) by scanning a surface (42) of the workpiece arrangement (22; 22a-c) in at least one first measuring plane (44; 44a-c) and creating at least one second surface profile (50; 50a-c) by scanning the surface (42) of the workpiece arrangement (22; 22a-c) in at least one second measuring plane (52; 52a-c); wherein the second measuring plane (52; 52a-c) is oriented transversely or perpendicularly to the first measuring plane (44; 44a-c); c) determining (54) at least one first characteristic profile change (56) in the at least one first surface profile (40; 40a-c) and at least one second characteristic profile change (58) in the at least one second surface profile (50; 50a-c); d) determining (60) at least one desired machining coordinate (62) as a function of the at least one first profile change (56) and the at least one second profile change (58). 2. Computer-aided method (10) according to claim 1, wherein the at least one first measuring plane (44; 44a-c) has a measuring distance (91), in particular along the at least one second measuring plane (52; 52a-c), to the predetermined processing coordinate (36). 3. Computer-aided method (10) according to one of the preceding claims, wherein at least one further first surface profile (40; 40a-c) is created by scanning the surface (42) of the workpiece arrangement (22; 22a-c) in at least one further first measuring plane (90); wherein the at least one further first measuring plane (90) is formed parallel to the at least one first measuring plane (44; 44a-c). 4. Computer-aided method (10) according to claim 2 or 3, wherein in method step c) a desired machining path (84) is determined from the at least one first surface profile (40; 40a-c) and/or the at least one first surface profile (40; 40a-c) and the at least one further first surface profile (40; 40a-c). 5. Computer-aided method (10) according to one of the preceding claims, wherein at least one further second surface profile (50; 50a-c) is created by scanning the surface (42) of the workpiece arrangement (22; 22a-c) in at least one further second measuring plane (86); wherein the at least one further second measuring plane (86) is formed parallel to the at least one second measuring plane (52; 52a-c). 6. Computer-aided method (10) according to claims 3 to 5, wherein several, in particular a multiplicity of, further first surface profiles (40; 40a-c) and/or further second surface profiles (50; 50a-c) are created. 7. Computer-aided method (10) according to claim 6, wherein the first measuring planes (44; 44a-c; 90) and/or the second measuring planes (52; 52a-c; 86) are each formed at an equal distance from one another. 8. Computer-aided method (10) according to one of the preceding claims, wherein the measuring planes (44; 44a-c; 52; 52a-c; 86; 90) form a rectangular, in particular square, measuring field (72) on the surface (42) of the workpiece arrangement (22; 22a-c). 9. Computer-aided method (10) according to one of the preceding claims, wherein in method step c) a contact joint start (89) and/or a contact joint end is determined from the at least one first surface profile (40; 40a-c) and/or from the at least one second surface profile 50; 50a-c); wherein the target processing coordinate (62) is determined as the contact joint start (89) or the contact joint end. 10. Computer-aided method (10) according to one of the preceding claims, wherein optical coherence tomography is used to carry out the method (10). 11. Computer-aided method (10) according to one of the preceding claims, wherein the method steps a) to d) are carried out for several, in particular each, predetermined processing coordinate (36) along a predetermined processing path (32) of the processing optics (12). 12. Computer-aided method (10) according to claim 11, wherein the method steps a) to d) are carried out at a constant feed rate of the sensor (26) along the predetermined machining path (32) and/or a desired machining path (84). 13. Measuring arrangement (70; 70a-c) with a measuring system (28) having a sensor (26) and a workpiece arrangement (22; 22a-c) formed from two workpieces (18, 20), wherein the measuring system (28) is set up to carry out a computer-aided method (10) according to one of the preceding claims. 14. Manufacturing system (64) with a laser processing machine (14) and a measuring arrangement (70; 70a-c) according to claim 13, wherein the sensor (26) of the measuring system (28) is arranged on a processing optics (12) of the laser processing machine (14).