Method for the operation of a laser-cutting device, laser-cutting device, and system

Abstract

The invention relates to a method for operating a laser-cutting device, comprising the following steps: a) providing a data set containing images of machined workpieces having cut edges, and containing objectified cut-edge features associated with the images; b) displaying images of the cut edges from the data set on a display means, the cut edges differing in terms of the objectified cut-edge features; c) input from a user to analyze the displayed cut edges; d) creating and / or optimizing user-customized operating parameters of the laser-cutting device on the basis of the user input analyzing the cut edges.

Description

[0001] Title: Method for operating a laser cutting system,

[0002] Laser cutting system

[0003] Description

[0004] The invention relates to a method for operating a laser cutting system, a laser cutting system for laser cutting and a system with a laser cutting system and a display means designed separately from the laser cutting system.

[0005] Laser cutting systems are primarily used for cutting workpieces made of metal or other materials. An optimal cutting process must be designed with regard to cutting quality, cutting speed, gas consumption, robustness against interference, and machine autonomy. The cutting process can generally be optimized in all three criteria, but at least cutting quality and cutting speed are contradictory.

[0006] EP 4 119 284 A1 discloses a calibration of a quality estimator for industrial laser processing. Immediately following laser processing, the quality estimator uses an imaging technique to inspect and measure cutting edge characteristics of a cutting edge of the workpiece, and from this, determines objective cutting edge characteristics, such as roughness, burr, and slag adhesion. The operating parameters of the laser processing are subsequently optimized based on the determined cutting edge characteristics.

[0007] The operating parameters are optimized by linking cutting edge characteristics to individual operating parameters. Based on the cutting edge characteristics determined by the quality estimator, the individual operating parameters are then modified to improve, for example, roughness, burr, and slag adhesion.

[0008] However, this leads to the operating parameters being adjusted equally for all cutting edge characteristics without taking into account the individual requirements of a user, particularly a machine operator, a shift supervisor, a company, or an industry. This is problematic because the quality perception of laser-cut edges is subjective.

[0009] The invention is therefore based on the object of providing a user with individualized and optimized operating parameters for a laser cutting system.

[0010] The object underlying the invention is achieved by the method having the features of claim 1. The method for operating a laser cutting system comprises the following

[0011] Process steps, especially in the specified

[0012] Sequence: a) Providing a data set with images of machined workpieces with cutting edges and with objective cutting edge features assigned to the images; b) Displaying images of the cutting edges from the data set on a display means, wherein the cutting edges are differentiated based on the objective cutting edge features; c) Input from a user for evaluating the displayed cutting edges; d) Creating and / or optimizing operating parameters of the laser cutting system that are individualized for a user depending on the user input evaluating the cutting edges.

[0013] Consequently, the user’s individual and / or subjective quality requirements can be taken into account when creating and / or optimising the operating parameters. The user does not realise how the operating parameters are influenced because he only evaluates the cutting edge as such. This further objectifies his evaluation. Furthermore, the user’s evaluation, in particular the input of his individual and / or subjective quality requirements, is made easier by the user input. The user therefore does not have to deal with a large number of complex cutting edge features, but can carry out the evaluation quickly and easily using images. The linking of the cutting edge features and the images of the cutting edges preferably takes place in the background.

[0014] The representation of the cutting edges and its objective

[0015] Cutting edge features as images rather than values ​​provide a simple graphical visualization of the objectified cutting edge features, making it significantly easier for the user to make a decision regarding the desired cutting edge results. The images serve as a representation of the objectified cutting edge features. It is not clear to the user which objectified cutting edge feature and which characteristic they prefer, nor which operating parameters will be derived from it.

[0016] One or more of the following features can be considered as objectifiable and / or objectifiable cutting edge features: roughness, burr, slag adhesion, discoloration, homogeneity.

[0017] For example, a 3D point cloud can be generated for the burr and the cutting edge. Objective main metrics or submetrics can be derived from the point cloud, e.g., the mean burr maximum (Bp value), the mean roughness (Ra), and / or the average roughness depth (Rz) at different depths.

[0018] It is advantageous if the creation and / or optimization of the individualized operating parameters also takes place depending on the material to be processed. Thus, an individualized quality can be provided for each material.

[0019] Preferably, the metrics of the objective cutting edge features, i.e., the specific values ​​of the cutting edge features, are not displayed when displaying the images of the cutting edges. It is advantageous if, particularly following step d), the following method step is performed: e) Cutting, in particular laser cutting, a workpiece using the created and / or optimized operating parameters.

[0020] Accordingly, the individualized operating parameters can be used to cut a workpiece.

[0021] An advantageous further development of the method comprises the following steps for providing the data set, in particular in the order listed:

[0022] Processing of components to produce components with at least one cutting edge;

[0023] Taking pictures of the cutting edges;

[0024] Measuring the cutting edges to objectify cutting edge features;

[0025] Assigning the observed cutting edge features to the images; and

[0026] Saving an image and the corresponding objectified cutting edge features in the dataset .

[0027] Accordingly, the data set comprises at least one image of the cutting edge and one or more cutting edge features associated with the image.

[0028] It is advantageous if the workpieces are processed according to step a) for generating the data set in such a way that as many combinations of the cutting edge features and their characteristics as possible are included. The number of images can preferably be calculated according to the following formula: Number of images = a * n xwhere x corresponds to the number of considered cutting edge features, n to the occurrences of the cutting edge features, and a to the number of images per occurrence of a cutting edge feature. Preferably, the database comprises at least 10,000 images.

[0029] It is also advantageous if the cutting edges are measured by means of an optical measuring device, in particular an imaging method and / or by means of a tactile measuring device.

[0030] An advantageous development provides that the images are displayed and the user input is carried out in such a way that the cutting edges are evaluated using a discrete scale. A discrete scale could, for example, comprise evaluation points from 1 to 5, from 1 to 10 or from 1 to 100. A further advantageous development provides that the images are displayed and the user input is carried out in such a way that the cutting edges are evaluated based on a comparison between several, in particular two or three, displayed cutting edges. Accordingly, several images are displayed simultaneously, with the user selecting the better or the worse cutting edge. Both evaluation variants can also be combined. First, the evaluation can be carried out using a discrete scale and then based on a comparison.

[0031] It is advantageous if the display of the images and the user input comprise the following steps, in particular in the order shown: display of cutting edges which differ with regard to one, in particular a single, objectified cutting edge feature;

[0032] If the evaluation does not differ despite the different objectified cutting edge feature: filter the data set so that only cutting edges with a single characteristic of this objectified cutting edge feature are presented to the user;

[0033] Repeat the previous steps .

[0034] For example, the user can first be shown cutting edge 1 and then cutting edge 2.

[0035] The objective cutting edge characteristics of cutting edge 1 and cutting edge 2 are shown in the table below. The cutting edge was measured, for example, with regard to burr, roughness, and discoloration. This subsequently resulted in characteristics that were categorized, in this case, on a scale from 1 for very poor to 5 for very good.

[0036] Cutting edge 1 :

[0037] Cutting edge 2 :

[0038] If the user rates cutting edge 1 and cutting edge 2 equally, e.g., with 3 rating points, it can be concluded that the burr, despite the rating of 1 (very poor) for cutting edge 1 and 5 (very good) for cutting edge 2, is of no relevance to the user. If the rating points differ only slightly, e.g., 2 rating points for cutting edge 1 and 3 rating points for cutting edge 2, it can be concluded that the burr is of little relevance to the user. If the deviation is high, it can be concluded that the burr is of high relevance. Depending on the rating difference, the cutting edge characteristic "burr" can be weighted when optimizing the operating parameters.

[0039] Furthermore, for the first case (no relevance) and / or the second case (low relevance), images from the dataset with different characteristics of this cut-edge feature can be removed. Since the cut-edge feature has no influence on the evaluation, the evaluation can be abbreviated accordingly. Consequently, the dataset can be reduced step by step. Thus, the individual and / or optimal set of cut-edge features for the user can be determined quickly and easily.

[0040] A search algorithm for selecting the next image is preferably used to determine a robust quality fingerprint—i.e., a data set for determining the subjective perception of quality—from a small number of images to be displayed. The quality fingerprint can be defined for specific customers and / or customer segments and / or industries. The individualized operating parameters, particularly depending on the material and / or other boundary conditions, can then preferably be determined from the data set.

[0041] It is also advantageous if a comparison process, such as an Analytical Hierarchy Process (AHP), is carried out to evaluate the weighting of the cutting edge features and / or the characteristics of the cutting edge features.

[0042] It is further advantageous if the creation and / or optimization of the operating parameters of the laser cutting system takes place on the basis of a weighting of the objective cutting edge features. Accordingly, a set of operating parameters is preferably created which corresponds to the weighted cutting edge features. The objective cutting edge features for which the user's assessment differed, in particular significantly, for different characteristics of a cutting edge feature are given a higher weighting, and the objective cutting edge features for which the user's assessment did not differ, in particular not significantly, for different characteristics of a cutting edge feature are given a lower weighting. A significant difference could be on a discrete scale such as 1, 2, ...9, 10, e.g.2 or 3 rating points, i.e. more than 20% or 30% of the difference between the minimum and maximum rating points.

[0043] Preferably, the operating parameters are created and / or optimized offline. This allows the subjective quality characteristics to be determined independently of a specific process. It is conceivable that the subjective quality characteristics are recorded before the first cutting process, and the operating parameters are then created and / or optimized. Consequently, optimal and / or customized cutting parameters can be generated for the user starting with the first cutting process. Laser cutting by the user is not necessary for evaluation and optimization.

[0044] The object underlying the invention is also achieved by a laser cutting system having the features of claim 13. The laser cutting system serves for laser cutting a workpiece using individualized operating parameters, wherein the laser cutting system comprises a display means for displaying images of cutting edges and for receiving a user input from a user, wherein the laser cutting system is set up according to the method described above.The object underlying the invention is also achieved by a system with a laser cutting system for laser cutting a workpiece and with a display means designed separately from the laser cutting system, in particular a computer, laptop, smartphone, tablet or other wearable, for displaying images of cutting edges and for receiving a user input from a user, wherein the system is set up according to the method described above, and wherein the system is further set up to display images of the cutting edges on the display means and to receive a user input by means of the display means.

[0045] Further details and advantageous embodiments of the invention can be found in the following description, on the basis of which an embodiment of the invention is further described and explained.

[0046] It shows :

[0047] Fig. 1 is a schematic representation of a method according to the invention;

[0048] Fig. 2 is a schematic representation of the representation and evaluation of the cutting edges;

[0049] Fig . 3 is a schematic representation of a first

[0050] cutting edge;

[0051] Fig. 4 is a schematic representation of a second

[0052] cutting edge; and

[0053] Fig . 5 is a schematic representation of a third

[0054] Cutting edge. Fig. 1 schematically illustrates eight process steps for operating a laser cutting system. First, according to step S10, a plurality of workpieces are processed in a laser cutting process to produce cutting edges with different cutting edge features and characteristics.

[0055] According to step S 12, the cut edges are measured using an imaging measurement method, whereby, among other things, the roughness, burrs, and discolorations are quantitatively determined. The cut edge characteristics can be determined for each cut edge. It is also possible to divide the cut edge into regions in order to determine sub-cut edge characteristics in these regions. The measurement can be refined as desired.

[0056] According to step S 14, the images of the cutting edges are stored in a database with the associated cutting edge features. Accordingly, for each cutting edge or cutting edge region, there is a data pair containing an image of the cutting edge and a set of recorded cutting edge features of the cutting edge. The database can then be made available to the user for evaluation.

[0057] According to step S16, the images are displayed to the user on a display device on the laser cutting system or on a computer, tablet, or smartphone. The display of the images, the order of display, and the user input are shown in detail in Fig. 2.

[0058] In step S 16, the user is shown two or more images of cutting edges simultaneously or, in particular, directly one after the other, which essentially differ in the characteristics of a cutting edge feature. The user then makes an assessment in accordance with step S 18. In step S 16A, a check is then carried out as to whether sufficient information has been collected to evaluate the weighting of the cutting edge features. If this is the case according to B 1, the assessment is complete. If this is not the case according to B 2, a check is carried out in step S 16B as to whether the user input results in the database being adapted in accordance with condition B 4. The database is adapted in the sense that data pairs are filtered out or not shown to the user which show cutting edge features or their characteristics which have no or a negligible influence on the user's assessment of the cutting edges.This is the case when the user rates images with cutting edges as identical or similar, but where the characteristics of a cutting edge feature differ significantly. The database can therefore be reduced by displaying only images with one characteristic of the cutting edge feature. If the user's rating shows relevance for the cutting edge feature in question, cutting edges with different characteristics of this cutting edge feature will continue to be displayed according to condition B3. It is also conceivable for the user to use a rating to indicate the level of a cutting edge feature at which a cutting edge is unusable. In this case, the relevance of the cutting edge feature can only apply up to a specific level.

[0059] When the user evaluates the cutting edges, the database is further restricted and the weighting of individual cutting edge features comes closer to the subjective requirements of the user. As soon as sufficient information has been collected, several images of cutting edges with more complex sets of cutting edge features can be displayed for further checking, with the user entering their assessment as to which cutting edge is better. This is particularly useful if the characteristics of several cutting edge features differ or if the characteristics of one cutting edge feature differ only slightly. Finally, the user can be shown a cutting edge and the rating anticipated by the system for checking. If this matches the user's expectations, the assessment can be completed.Otherwise, the evaluation can be restarted or continued.

[0060] Following the user input, the final determination of the user-specific weighting of the cutting edge features is carried out based on the user input in step S20. By linking the cutting edge features with the evaluated images of the cutting edges by the user, the relevance and level of relevance of the individual cutting edge features, i.e., the weighting, can be determined. The weighting can preferably be determined by artificial intelligence.

[0061] Taking the weighting into account, individualized operating parameters are then created and / or optimized according to step S22. The cutting edge characteristics are related to one or more operating parameters. The operating parameters are created and / or optimized with respect to the two criteria of cutting quality and cutting speed, with the cutting quality being individualized for the application based on the user input.

[0062] Finally, workpieces can be laser cut according to step S24 using the individualized operating parameters.

[0063] Three different cutting edges are shown in Fig. 3 to 5. The first cutting edge 10 according to Fig. 3 has a considerable burr, which a user could rate as "very poor". The second cutting edge 12 according to Fig. 4 has unevenness which has a negative effect on the roughness. The user could rate this as "medium". The third cutting edge 14 according to Fig. 5 has an optimal cutting edge, although this is accompanied by a lower cutting speed.

Claims

Patent claims 1. Method for operating a laser cutting system, comprising the following steps: a) providing a data set with images of machined workpieces with cutting edges and with objective cutting edge features assigned to the images; b) displaying images of the cutting edges from the data set on a display means, the cutting edges being differentiated on the basis of the objective cutting edge features; c) input from a user for evaluating the displayed cutting edges; d) creating and / or optimizing operating parameters of the laser cutting system which are individualised for a user as a function of the user input evaluating the cutting edges.

2. The method of claim 1, further comprising the following step: e) cutting a workpiece using the created and / or optimized operating parameters.

3. Method according to claim 1 or 2, wherein the provision of the data set comprises the following steps: - Machining of components to produce components with at least one cutting edge; Taking pictures of the cutting edges; - Measuring the cutting edges to objectify cutting edge features; - Assigning the observed cutting edge features to the images; and - Saving an image and the corresponding objectified cutting edge features in the data set.

4. Method according to claim 3, wherein the processing of the components is carried out in such a way that cutting edges with different combinations of objective cutting edge features are provided.

5. Method according to claim 3 or 4, wherein the measuring of the cutting edges is carried out by means of an optical measuring device and / or a tactile measuring device. 6 . Method according to one of the preceding claims, wherein the display of the images and the user input are carried out in such a way that an evaluation of the cutting edges is carried out on the basis of a discrete scale.

7. Method according to one of the preceding claims, wherein the display of the images and the user input are carried out in such a way that an evaluation of the cutting edges is carried out on the basis of a comparison between a plurality of displayed cutting edges. 8 . Method according to one of the preceding claims, wherein the display of the images and the user input are carried out in such a way that first an evaluation of the cutting edges is carried out using a discrete scale and then using a Comparison is made between several displayed cutting edges.

9. Method according to one of the preceding claims, wherein the display of the images and the user input comprise the following steps: - Representation of cutting edges which differ with respect to an objective cutting edge feature; - If the evaluation does not differ despite the different objectified cutting edge characteristics: filter the data set so that only cutting edges with a single characteristic of this objectified cutting edge characteristic are presented to the user; - Repeat the previous steps.

10. Method according to one of the preceding claims, wherein the creation and / or optimization of the operating parameters of the laser cutting system is carried out on the basis of a weighting of the objective cutting edge features, wherein the objective cutting edge features are given a higher weighting for which the user's assessment has differed for different characteristics of an objective cutting edge feature, and wherein the objective cutting edge features are given a lower weighting for which the user's assessment has not differed for different characteristics of a cutting edge feature.

11. Method according to one of the preceding claims, wherein the creation and / or optimization of the operating parameters takes place off-line.

12. Method according to one of the preceding claims, wherein the images of the cutting edges are generated in such a way that the cutting edge in each case runs in the image plane of the image.

13. A laser cutting system for laser cutting a workpiece using individualized operating parameters, the laser cutting system comprising a display means for displaying images of cutting edges and for receiving user input from a user, the laser cutting system being configured according to the method according to any one of the preceding claims.

14. System with a laser cutting system for laser cutting a workpiece and with a display means designed separately from the laser cutting system for displaying images of cutting edges and for receiving a user input from a user, wherein the system is set up according to the method according to one of claims 1 to 12, and wherein the system is further set up to display images of the cutting edges on the display means and to receive a user input by means of the display means.

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