Method and system for tracking locations on a material web

Abstract

The present invention relates to a method for tracking locations (w1, w2, w3) on a material web (120, 122, 124) during the processing of the material web (120, 122, 124), said method comprising the steps of: - capturing first measurement data (300) of a first surface region (w1) of the material web (120), - processing the material web (122) in a process step, - determining modified first measurement data by applying at least one process ML model (172) to the first measurement data (300), and -identifying the first surface region (s1) on the processed material web (124) using the modified first measurement data.

Description

[0001] Method and system for tracking locations on a

[0002] Material web

[0003] The present invention relates to a method and system for tracking material webs during processing of the material web using measurement data regarding surface areas.

[0004] Such systems are known from the state of the art.

[0005] For example, the article "Integration of Traceability Systems in Battery Production" (Günther Riexinger et al., Procedia CIRP, Volume 93, 2020, pages 125–130, ISSN 2212-8271, https: / / doi.org / 10.1016 / j.procir.2020.04.002 (https: / / www.sciencedirect.com / science / article / pii / S221282712030531X)) reveals examples of traceability concepts with a focus on identification technologies in battery production. This article presents the developed traceability concepts and their implementation examples. Examples include methods for identifying an object or production element by tracking inherent object properties or applied identification markers.

[0006] A disadvantage of the cited prior art is that the known methods still have disadvantages with regard to the recognition accuracy of identification points or markings on products during associated production processes. One reason for this is that production processes can affect the cited identification points or markings, causing them to no longer correspond exactly to the originally present identification points or markings. Therefore, it is an object of the present invention to provide a method and / or system with which the recognition accuracy of identification points and / or markings on a product can be improved, even during the production of the product.

[0007] This object is achieved by a method having the features of patent claim 1 .

[0008] Such a method is designed and configured to track locations on a material web during processing of the material web and comprises the steps:

[0009] - Acquisition of initial measurement data of a first surface area of ​​the material web,

[0010] - Processing the material web in one process step,

[0011] - Determining modified first measurement data by applying at least one process ML model to the first measurement data and identifying the first surface area on the processed material web using the modified first measurement data.

[0012] In this context, the abbreviation "ML" stands for "machine learning" or "machine learning," particularly in the context of this description. Machine learning methods, ML models, the term "ML model" and / or the term "process ML model" will be explained in more detail in this description.

[0013] The method can, for example, be designed and configured as a computer-implemented method. Furthermore, all method steps of the method can be designed and configured as computer-implemented method steps. It can also be provided that a selection of the method steps of the method are designed and configured as computer-implemented method steps or computer-assisted method steps.

[0014] Furthermore, the process steps of the aforementioned process do not necessarily have to be performed consecutively or in the specified order. For example, some of them may also be performed simultaneously or in a different order. Furthermore, it may be provided that additional process steps are performed or are provided for between the process steps.

[0015] By using modified process ML models to identify surface areas of a material web after processing this material web in a process step, the identification of surface areas after processing is improved.

[0016] The aforementioned similarity comparison, or a corresponding identification process, frequently yields so-called "false positive" results. These so-called "false positives" are surface areas of the processed material web that were incorrectly identified as a different surface area of ​​the unprocessed material web. Reasons for such "false alarms" can include ambiguities, for example, in the visual fingerprints used in such a similarity comparison, e.g., due to imperfect images (regarding size, resolution, lighting conditions, noise), and the need to use relatively low detection thresholds to achieve sufficient identification of surface areas.

[0017] Such false positive results can, for example, be reduced or, under certain circumstances, even avoided entirely if the modified first measurement data are used to identify the first surface area on the processed material web. Using an appropriately designed, configured, and / or trained process ML model, a wide variety of changes to the material web, e.g., caused by the process step, and / or by any detection devices, measurement methods, and / or measurement conditions used during the identification process, can be taken into account, or at least partially taken into account, when identifying the first surface area on the processed material web.

[0018] For such a purpose, the process ML model can, for example, be designed, set up and trained in such a way that effects of the aforementioned causes (e.g. the aforementioned changes to the material web, e.g. as a result of the process step, and / or any detection devices, measuring methods and / or measuring conditions used in the identification process) on the first measurement data are simulated or at least partially simulated by applying the at least one process ML model to the first measurement data. This facilitates a corresponding similarity comparison of the first measurement data acquired before processing with measurement data acquired, for example, in the context of identifying the first surface area on the processed material web, e.g. further measurement data acquired or second measurement data.

[0019] The use of the modified initial measurement data thus obtained improves the identification of surface areas after processing by improving the detection accuracy of identification points and / or markings of a product, even during the production of the product.

[0020] The material web can consist of any material that can be formed, manufactured, and / or processed as a material web. For example, these can be materials that are designed and configured so that they can be unwound onto and / or from a roll. These are often very long and comparatively thin material webs. Such material webs can be made of, for example, plastics, metals, fabrics, paper, or similar materials.

[0021] Furthermore, it can be provided that the moving material web is moved, for example, in a transport direction, in particular is moved linearly in a transport direction. Furthermore, it can be provided that the moving material web is moved at a transport speed. This transport speed can, for example, be a constant transport speed or a variable transport speed. For this purpose, it can be provided that, for example, at least one speed meter is provided to measure the speed of the material web. Furthermore, the speed of the material web can also be determined using further parameters, such as a rotational speed of an unwinding roll or winding roll for the material web, possibly together with a corresponding radius of the unwinding and / or winding roll.Furthermore, other measurement variables can be used with the aid of which the speed of the moving material web can be determined, either in one of the ways mentioned above or in another way, or with the aid of which the speed of the moving material web is determined.

[0022] In general, measurement data within the scope of the present description, for example the first and / or second measurement data, can be, for example, all types of zero-dimensional, one-dimensional, and / or multi-dimensional data structures which are suitable for a similarity comparison and / or recognition of these data structures, for example in the context of identifying the first surface area on the processed material web.

[0023] In a preferred embodiment, the measurement data can be configured and configured as two-dimensional image data. The image data can be captured or have been captured, for example, by an optical capture device, such as a camera. The optical capture device can be configured and configured to capture measurement data in different spectral ranges, e.g., from the far infrared to the ultraviolet spectral range, or even in sub-ranges thereof.

[0024] Furthermore, corresponding one- or multi-dimensional image data can also contain temperature data recorded by a thermal camera, or electrical data (for example charges, currents or electric fields or field strengths) recorded by corresponding measuring devices or magnetic data (magnetic fields or field strengths).

[0025] With appropriate measuring devices, for example, one- or multi-dimensional, for example two-dimensional, chemical data or surface structure data (for example roughness, height profiles or height maps or similar data) can be recorded as measurement data.

[0026] A respective surface area of ​​the material web can be any limited two-dimensional area of ​​the material web. In particular, the surface area can be a contiguous area or comprise several non-contiguous sub-areas. Furthermore, the surface area can be limited, for example, by a regular geometric shape. It can, for example, be rectangular, square, circular, elliptical, or have similar shapes.

[0027] The first measurement data can be recorded, for example, using a first recording device.

[0028] Furthermore, the identification of the first surface area on the processed material web can be carried out using second measurement data relating to second surface areas of the processed material web. The second measurement data can be or have been acquired with a second acquisition device or also with the first acquisition device.

[0029] When acquiring the first measurement data, or additional measurement data, with the first acquisition device, the same acquisition or measurement parameters and / or transport speeds can be used. Furthermore, different acquisition or measurement parameters and / or transport speeds can also be used.

[0030] In the same way, when using a second detection device to identify the first surface area, the same detection parameters and / or transport speeds can be used, or different detection parameters and / or transport speeds can be used.

[0031] Furthermore, when identifying the first surface area on the processed material web, the same detection parameters and / or transport speeds can be used as when detecting the first measurement data with the first detection device.

[0032] Furthermore, the method can be designed and configured such that, as part of the acquisition of the first measurement data, a first point in time of this acquisition (hereinafter also referred to as the first acquisition point in time) is also recorded. Furthermore, it can be provided that, as part of the identification of the first surface area, second measurement data are acquired, and then second points in time of such acquisitions (hereinafter also referred to as the second acquisition points in time) corresponding to the respective second measurement data are also recorded.

[0033] Furthermore, within the scope of the acquisition of measurement data according to the present description, additional acquisition parameters can be recorded and / or stored. Such additional acquisition parameters can be, for example, a time of acquisition, a date of acquisition, setting parameters of the acquisition device, a lighting setting, a temperature during acquisition, a detection angle, a detection distance, and / or comparable acquisition parameters.

[0034] It can further be provided that, in addition to the modified first measurement data, additional measurement parameters acquired during the acquisition of the first measurement data are used when identifying the first surface area. Such additional measurement parameters can be designed and configured, for example, in accordance with the present description.

[0035] For example, measurement data can generally be recorded using a recording device and corresponding recording parameters, wherein the recording parameters can include, for example, a transport speed of the material web (e.g. at the time the first measurement data is recorded), the first time the measurement data is recorded, type and / or model of the recording device, additional information on the recorded measurement data (e.g. image size, data type, physical unit of the recorded measurement data, ...), setting parameters of the recording device, setup parameters or a recording arrangement of the recording device (e.g. distances and angles between the recording device and transport path), a type of lighting, a lighting arrangement, lighting parameters and / or similar recording parameters. A recording arrangement can, for example, include data that describes a setup of a recording device, such as, for example,Distances and angles between the detection device and the transport path, a type of lighting, a lighting arrangement, lighting parameters and / or similar arrangement parameters.

[0036] For example, the first measurement data can be acquired using a first acquisition device and first acquisition parameters in accordance with the present description.

[0037] In the same way, when second measurement data are acquired with a second acquisition device and the first surface area is identified using the second acquisition device, corresponding acquisition parameters can be acquired and / or stored.

[0038] For example, corresponding acquisition parameters can be recorded and / or stored in general when all measurement data are recorded in accordance with this description.

[0039] As already explained above, one or more recording devices can be provided to record the various measurement data mentioned in the method, which are designed and set up, for example, as appropriately designed and configured cameras or other sensors for recording corresponding measurement data. The recording of the one-dimensional or multi-dimensional data structures can take place, for example, in a single measuring step, such as with a 2D camera, or by appropriate scanning, e.g. with a point sensor or 1D sensor. In this way, for example, a 2D data structure, such as an optical image, can be generated by using an 1-dimensional camera (e.g. a so-called line scan camera) aligned perpendicular to a direction of movement of the material web and, for example, an image is recorded while the material web is moving beneath the line scan camera.

[0040] The detection devices can be designed and configured, for example, as a camera, e.g., a 3D, 2D, or line-scan camera, an RGB or grayscale camera, an infrared or ultraviolet camera, and / or a hyperspectral camera. Furthermore, the detection device can be designed and configured as a height or surface detection device.

[0041] Furthermore, a detection device according to the present description can be designed and configured, for example, as a camera (e.g. hyperspectral line camera or RGB camera), an optical line sensor, an optical sensor, a magnetic sensor, a motion sensor, a location sensor, a material sensor, a touch sensor, and / or any other type of sensor.

[0042] Measurement data according to the present description can be all data or data structures output by a recording device according to the present description and / or transmitted or transmittable to an external device, such as a control device, an edge device, an industrial PC (IPC) and / or another computer device (e.g. databases, data collections, ID data structures or ID data, 2D data structures or 2D data, 3D data structures or 3D data, or even higher-dimensional data or data structures). Such measurement data can be, for example: optical data (e.g. OD data, ID data, 2D data (e.g. a 2D image), 3D data (e.g. a 3D image)), electrical properties or information (e.g. resistance, conductivity, ...), magnetic properties or information, volume measurement variables, area measurement variables, state data (e.g. pressure, temperature, ...), movement parameters (e.g.Location, speed, flow rate or speed, ...) or other measurement data.

[0043] The recording of the times can be performed, for example, by the recording device or another time-measuring device, such as a corresponding clock, which is synchronized with the recording device. These times can be recorded and / or stored, or can be recorded and / or stored, as clock times or other time signals, such as counters or comparable data.

[0044] The second detection device can, for example, correspond to the first detection device or can also be the first detection device itself. Furthermore, the second detection device can, for example, have the same measuring principle as the first detection device. Furthermore, the second detection device can, for example, be designed and configured to be identical, similar or comparable to the first detection device or can also differ therefrom. The second measuring device can be designed and configured such that the measurement data acquired by it are comparable with the measurement data acquired by the first detection device in such a way that an identification of the first surface area according to method step d and an identification of the second surface area according to method step e is possible.For this purpose, it may also be necessary, after the first and / or second measurement data have been recorded, to carry out appropriate adjustments, standardizations, conversions or similar processing steps on these data before one of the above-mentioned identifications of surface areas is or can be carried out.

[0045] When recording measurement data with the second recording device, for example, the same measurement parameters can be used as when recording measurement data with the first recording device, or other, adapted or comparable measurement parameters can be used.

[0046] A process step or process sub-step within the scope of the present description can also be designed and configured as a recording of second measurement data within the scope of identifying the first surface area on the processed material web. In this case, the identification of the first surface area on the processed material web can take place, for example, using the modified first measurement data and the second measurement data. In particular, within the scope of identifying the first surface area on the processed material web, a comparison of the modified first measurement data with the second measurement data can take place. For example, it can be provided that the recording of the first measurement data takes place with a first recording device using first recording parameters and / or a first recording arrangement.The aforementioned second measurement data can be acquired using a second acquisition device using second acquisition parameters and / or using a second acquisition arrangement. The second acquisition device can be the same as the first acquisition device or different therefrom. The second acquisition parameters can be the same as the first acquisition parameters or different therefrom. And the second acquisition arrangement can be the same as the first acquisition arrangement or different therefrom.

[0047] It can then be provided, for example, that a process step or process sub-step within the scope of the present description comprises capturing the second measurement data with a second capturing device different from the first capturing device and / or using second capturing parameters different from the first capturing parameters and / or using a second capturing arrangement different from the first capturing arrangement, or is designed and configured as such capturing.

[0048] Process steps or process sub-steps within the scope of the present description can also be any type of method or processing step with which material webs can be processed. This can be, for example, applying materials to a material web, heating, cooling, drying, pressing / calendering, winding, unwinding and / or printing a material web and / or comparable process steps. A process step according to the present description can also comprise several of the above-mentioned process steps as process sub-steps.

[0049] For example, such material strips are used in the manufacture of batteries and accumulators, for example, to produce electrodes for them. For example, an electrode material is applied to a carrier film, which is dried and then pressed ("calendered"). This electrode strip can then be separated into individual material segments for subsequent production steps.

[0050] Since batteries and / or rechargeable batteries are, or are to be, manufactured using such electrode tracks in later process steps, it is helpful or even necessary to trace the electrode track used for production through the various process steps in a spatially resolved manner in order to track the manufacturing process of the individual batteries or rechargeable batteries. The aim is, for example, to be able to later trace the cause of the underlying error in the case of faulty batteries and / or rechargeable batteries. For this purpose, it is advantageous to know those areas of the electrode track that were used in the respective battery or rechargeable battery and to trace them across the production steps. In this way, for example, the cause of a fault can be determined, which makes it possible to possibly improve the manufacturing process accordingly. Furthermore, the above information can also be used to test other batteries or rechargeable batteries.Batteries are identified that are or could be faulty based on the tracking data.

[0051] Furthermore, process steps and / or process sub-steps can be any type of acquisition of measurement data relating to surface areas of material webs - for example, using corresponding acquisition devices. The term "spatially resolved" in the context of the present description means that information is at least partially and at least in one spatial dimension correlated or provided with location information or position information or is assigned or assignable to location information or position information. In the present case, a spatial resolution can, for example, be designed and configured in such a way that measurement data are at least partially provided with or correlated with position or location information in a longitudinal direction and / or transport direction of the material web or that such position or location information is assigned or assignable to the measurement data.

[0052] Another example of the processing of material webs is the printing of newspapers and magazines, where colors are applied to a paper web in various process steps, with additional coatings potentially being applied. In the production of roofing membranes, for example, various waterproofing materials are applied to a paper or fabric web and reinforced and coated with various additional coating materials.

[0053] Even in these cases, spatially resolved tracking of the corresponding material webs can be helpful later, or even during the production process, in quality control or in determining the causes of errors and can significantly improve such measures.

[0054] A method according to the present description can, for example, be designed and configured in such a way that the measurement data relating to a specific surface area, e.g. characteristic of an appearance, a structure, a surface relief and / or other surface properties,

[0055] Surface parameters and / or material properties of the surface area are . Furthermore, the process step for processing the surface area or the material web can be designed and set up in such a way that the surface is changed with regard to, for example, the properties mentioned above. This change can be designed and set up in such a way that, for example, the properties of the surface are changed in such a way that a comparison of the measured data relating to the surface area before the process step with that which is recorded after the process step, a recognition of a surface area after the process step has been carried out is made more difficult, can become difficult, or is or can even be impossible.

[0056] For example, the properties of surfaces can change as the material web is wound up, for example, by transferring surface structures from a piece of material adjacent to the wound roll to a piece of material underneath (the structure can, for example, "push through"). Surface properties and / or structures can also be changed or be changeable, for example, when a material web is pressed with a press roller, coated, or dried.

[0057] Furthermore, when acquiring measurement data for identifying the first surface area on the processed material web, different measurement principles, acquisition parameters, settings, data formats, and / or a different measurement setup may be used. Even in such a case, such changes may make it difficult or even impossible to recognize a surface area based on acquired measurement data.

[0058] If the first measurement data are recorded with a first recording device and, as part of identifying the first surface area of ​​the processed material web, for example, second measurement data from surface areas of the processed material web are recorded with a second recording device, further changes can occur or effects of differences on the measurement data recorded before and after processing can arise. Such changes or effects can occur, for example, if there are differences between the first and second recording devices, differences between measurement parameters when recording the first and second measurement data and / or differences in different measurement arrangements when recording the first and second measurement data.The detection devices, the measuring parameters and / or the measuring arrangements can be designed and configured, for example, in accordance with the present description.

[0059] For example, the process ML model can be designed and configured such that an application of the process ML model to the first measurement data simulates, partially simulates, or includes such a simulation of an effect of the process step on the first surface area or the material web on measurement data acquired as part of the identification of the first surface area. Furthermore, the process ML model can, for example, be designed and configured such that an application of the process ML model to the first measurement data simulates, partially simulates, or includes such a simulation of an effect of the use of a modified detection device, of modified measurement parameters and / or a modified measurement arrangement on measurement data acquired as part of the identification of the first surface area.

[0060] In an advantageous embodiment, it can be provided, for example, that the process ML model is designed and configured in such a way that an application of the process ML model to the first measurement data simulates, partially simulates or comprises such a simulation an effect of the process step on the first surface area of ​​the material web, and / or an effect of the use of a modified detection device, of modified measurement parameters and / or a modified measurement arrangement, on measurement data acquired in the context of the identification of the first surface area.

[0061] The fact that an application of a process ML model to specific measurement data comprises a specific simulation means, in the context of this description, that the mentioned effect of the process ML model is or can be only a part of the overall effect of the process ML model.

[0062] For example, the formulation that an application of a process ML model to certain measurement data simulates or partially simulates a change in the measurement data due to an effect of a certain process step on a surface area assigned to the measurement data or includes such a simulation can mean that the said application of the process ML model to the measurement data, in addition to the effect of the process step on the measurement data, also simulates, for example, influences of other processes, settings, parameters, recording devices, measurement arrangements or similar on the measurement data.For example, the process ML model can be designed and configured in such a way that an application of the process ML model to certain measurement data simulates or partially simulates a change in these measurement data due to an effect of the process step on the surface area assigned to the measurement data, as well as due to further recording devices, further measurement parameters and / or a further measurement arrangement.

[0063] The above-mentioned embodiment by means of an application of the process ML model to the first measurement data has the advantage that, for a known process step, the process ML model can, for example, be trained in such a way that the effects of the process step on measurement data acquired with regard to a surface area are simulated or partially simulated by applying the process ML model to the measurement data originally recorded with regard to this surface area. The measurement data can, for example, be the first measurement data according to the present description. In this way, a change in a surface area as a result of the process step can be simulated.

[0064] Furthermore, a process ML model can simulate the use of a second acquisition device that is different from the first acquisition device or include such a simulation. A process ML model can also simulate the use of measurement parameters and / or measurement arrangements that are different from those used for data acquisition with the first acquisition device or include such a simulation.

[0065] In the context of this description, a measuring arrangement is understood to mean, for example, a spatial arrangement and / or installation of a measuring device. Such a spatial arrangement can include, for example, a distance and corresponding viewing angle of the detection device from the material web. Furthermore, the measuring arrangement can also include, for example, the type and arrangement of an illumination device that is or can be used, for example, in the context of the detection of the measurement data by the detection device.

[0066] The fact that the process ML model simulates or partially simulates a specific process step and / or a measurement data acquisition with a specific acquisition device using specific measurement parameters and / or measurement arrangements or comprises such a simulation means that the above-mentioned simulations are at least part of the effect of the process ML model on measurement data entered into the process ML model.

[0067] In this case, the process ML model can, among other things, also be designed and configured such that an application of the process ML model to measurement data acquired with regard to a surface region of a material web simulates or at least partially simulates a change in the measurement data due to an effect of a specific process step on the surface region and / or a change in the measurement data due to detection of the surface region with the second detection device or comprises such simulations. The simulation of the detection of the measurement data with the second detection device comprises measurement parameters and / or measurement arrangements used. In this case, the measurement data, the detection of the measurement data, the second detection device, the surface region, the process step and / or the effects of the process step on the measurement data can be designed and configured, for example, in accordance with the present description.

[0068] By using modified measurement data generated by the process ML model in the context of identifying a surface area, for example the first surface area, the recognition of the mentioned surface areas can be improved or, under certain circumstances, even made possible in the first place by comparing the measurement data recorded from the processed material web with the modified measurement data mentioned.

[0069] Such a process ML model can be created, for example, for winding up a material web or for successive winding and unwinding of a material web, and can simulate, or at least partially simulate, the transfer of structures from material web regions to adjacent material web regions on a wound roll. Furthermore, a process ML model can also be created, for example, for pressing or calendering a material web, and can simulate, or at least partially simulate, the effect of a surface structure of a specific press roller on the material web, for example through appropriate training.Corresponding process ML models can be generated or can be generated, for example, for all process steps according to the present description and / or also for the acquisition of measurement data with a specific acquisition device, specific acquisition parameters and / or a specific acquisition arrangement.

[0070] When assigning an individual process step to a process ML model, it can be provided, as already explained above, that the at least one process ML model is designed and configured as a process ML model in such a way that an application of the process ML model to measurement data acquired with regard to a surface area before carrying out the process step simulates, at least partially simulates or comprises such a simulation, a change in these measurement data due to an effect of the process step on the said surface area. The modified measurement data generated by the application of the process ML model to the said measurement data can then simplify identification of the surface area after carrying out the process step or, under certain circumstances, make it possible in the first place.

[0071] Furthermore, it can be provided that the process step comprises several process sub-steps, but only one process ML model is created for the entire process step composed of several sub-steps. In this case, it can also be provided that the process ML model simulates, or at least partially simulates, the effects of the entire process step on corresponding measurement data. In this case, each of the process sub-steps can be designed and configured as a process step according to the present description.

[0072] In a further case, in which a specific process step comprises a plurality of process sub-steps, it can be provided that each of the process sub-steps is assigned a process ML model of the said at least one process ML model. Then, each of the process ML models simulates the effects of a specific process sub-step on corresponding measurement data. In a process step consisting of process sub-steps, measurement data modified by the entire process step can then be calculated in such a way that measurement data relating to a surface area of ​​the material web not yet processed by the process step is recorded. The process ML model of the first process sub-step is then applied to this measurement data. The process ML model of the next process sub-step is then applied to the modified measurement data generated in this way in order to generate further modified measurement data.In this way, the effect of the entire process step on the measurement data acquired with respect to the specified surface area is simulated in the order of the process sub-steps performed by applying the respectively assigned process ML models. The measurement data obtained after applying the process ML model of the last process sub-step of the process step then correspond to the modified measurement data according to the present description.

[0073] In the context of this description, the term "simulated" is understood to mean both a relatively good approximation or simulation and any partial, approximate or even rudimentary simulation of the effect of the process step on the measurement data. Furthermore, the quality of such a simulation can also depend on the measurement data itself, or at least partially depend on or be influenced by it. For example, for some of the measurement data, the result of applying a specific process ML model according to this description can represent a relatively good simulation of the process step on the measurement data, while for other measurement data the application of this process ML model can only result in a poorer or even inadequate or unusable simulation.

[0074] The fact that a process ML model simulates, partially simulates or includes such a simulation the effect of a process step on measurement data recorded with regard to a specific surface area can also be designed and configured in such a way that the process ML model, in addition to this process step, also simulates the effect of one or more further process steps on the recorded measurement data.

[0075] Process ML model can, for example, be designed and configured as an ML model according to the present description.

[0076] The process ML model can in particular be an ML model according to the present description. The process ML model can be designed and configured such that an application of the process ML model to measurement data acquired with regard to a surface area of ​​a material web before processing by a process step simulates or at least partially simulates a change in the measurement data due to an effect of the process step on the surface area and / or the effects of changed acquisition parameters and / or acquisition conditions directly on the measurement data. The measurement data, the acquisition of the measurement data, the surface area, the process step and / or the effects of the process step on the measurement data can be designed and configured, for example, according to the present description.

[0077] The process ML model can in particular be an ML model according to the present description, which is designed and configured in such a way that an application of the process ML model to the first measurement data, and optionally further measurement data, simulates or at least partially simulates a change in the first and optionally further measurement data due to an effect of the process step on measurement data acquired with regard to the first and optionally further associated surface areas.

[0078] In an advantageous embodiment of the invention, the process ML model can be designed and configured, for example, as a neural network, in particular as a deep neural network (DNN). A machine learning method is understood to be, for example, an automated ("machine") method which does not generate results using predetermined rules, but in which, by means of a machine learning algorithm or learning method, regularities are (automatically) identified from many examples, on the basis of which statements about the data to be analyzed are then generated.

[0079] Such machine learning methods can, for example, be designed and implemented as a supervised learning method, a semi-supervised learning method, an unsupervised learning method or even a reinforcement learning method.

[0080] Examples of machine learning methods include regression algorithms (e.g. linear regression algorithms), the creation or optimization of decision trees (so-called "decision trees"), learning methods for neural networks, clustering methods (e.g. so-called "k-means clustering"), learning methods for or creation of support vector machines (SVMs), learning methods for or creation of sequential decision models or learning methods for or creation of Bayesian models or networks.

[0081] One example of a machine learning method is linear regression. Linear regression is a parametric method in which the labels are approximated by weighting all features. In a standard variant of the linear model, the mean squared error (MSE) is minimized during optimization. There are other variants of the linear model that differ in the form of the error function. One variant is the Huber estimator, in which a parameter E is introduced to eliminate outliers in the inputs.

[0082] Another example of a machine learning method is the k-nearest-neighbor method. The principle of the k-nearest-neighbor (k-NN) model is to determine the k nearest inputs for each input. It is a non-parametric method in which the similarity criterion is a defined metric. This metric can be a norm or a distance that can be determined for all inputs. The neighborhood of the labels is derived from the neighborhood or similarity of the inputs.

[0083] Decision trees are another example of an ML model that is based on a machine learning method.

[0084] A decision tree (DT) is a hierarchical structure that can be used to implement non-parametric estimation. In data processing with decision trees, the inputs are divided into local regions whose distance from each other is defined by a certain metric. These local regions are the decision trees.

[0085] A decision tree is a sequence of recursive partitions consisting of decision nodes and terminal nodes or leaves. At each decision node, a discrete decision is made using a defined function, the so-called discriminant function. The result (yes or no) leads to the subsequent nodes. When a leaf node is reached, the process ends and an output value is provided.

[0086] The result of applying such a machine learning algorithm or learning method to specific data is referred to, particularly in this description, as a "machine learning" model or ML model. Such an ML model represents the digitally stored or storable result of applying the machine learning algorithm or learning method to the analyzed data.

[0087] The generation of the ML model can be designed and configured in such a way that the ML model is newly created by applying the machine learning method or an existing ML model is changed or adapted by applying the machine learning method.

[0088] Examples of such ML models are results of regression algorithms (e.g. a linear regression algorithm), neural networks, decision trees, the results of clustering methods (including, for example, the obtained clusters or cluster categories, definitions and / or parameters), support vector machines (SVM), sequential decision models or Bayesian models or networks.

[0089] Furthermore, different categories of ML models can be combined into a single ML model. Ensemble learning involves combining different ML models to achieve better inference. The combined ML models form a so-called ensemble. There are various methods for combining models: voting, bagging, or boosting.

[0090] There is also what is known as automated machine learning. Automated machine learning (AutoML) is a process by which, for given tasks or data sets, an algorithm attempts to determine the best learning strategy from a specific number of machine learning methods or ML models. With AutoML, the algorithm searches for the best preprocessing steps and the best machine learning methods or the best ensemble. AutoML can be combined with meta-learning. Meta-learning, also called "learning to learn," is the science of systematically observing how different ML approaches perform on a variety of learning tasks and then learning from this experience (metadata) to learn new tasks much faster than would otherwise be possible.

[0091] A good implementation of AutoML is provided by the AUTO-SKLEARN software library (https: / / www.automl.org / automl / auto-sklearn / ). This system can create an ensemble of up to 15 estimators. In addition, it can utilize up to 14 feature preprocessing methods and four dataset preprocessing methods.

[0092] Neural networks can be, for example, so-called "deep neural networks," "feed-forward neural networks," "recurrent neural networks," "convolutional neural networks," or "autoencoder neural networks." The application of corresponding machine learning methods to neural networks is often referred to as "training" the corresponding neural network.

[0093] Decision trees can be designed and configured, for example, as so-called "iterative dichotomizer 3" (ID3), classification or regression trees (CART), or even so-called "random forests." An ML model or "machine learning" model, particularly in the context of this description, is understood to be the result of applying a machine learning algorithm or learning method to specific data. An ML model represents the digitally stored or storable result of applying the machine learning algorithm or learning method to the analyzed data.

[0094] The ML model can, for example, be present, stored or storable in a form that allows the ML model to be applied to new data to generate a result. Such an application of an ML model to data is also referred to as "inference". Furthermore, it can be provided that the ML model in the present, stored or storable form is also designed and configured to train the ML model. However, it can also be provided that the ML model in the present, stored or storable form is no longer designed and configured to train the ML model. In particular, in this case the ML model can only be designed and configured to be applied to data to generate a result, the aforementioned "inference".

[0095] Data for creating and / or training an ML model according to the present invention can, for example, be historical data from the first and / or second detection device or can include such data. Furthermore, data for creating and / or training the ML model can include historical data from detection components that are identical, similar, or comparable to the first and / or second detection component, or also historical data from components of the same category or of the same type as the first and / or second detection component.of the ML model with measurement data from other acquisition components, or also the use of other ML models with measurement data from other acquisition components, the creation and / or training of such an ML model can also be carried out with historical data from these acquisition components, comparable acquisition components or acquisition components of a similar or comparable component type.

[0096] A neural network is understood, at least in the context of this description, to be, for example, an electronic device with a computer program, a computer program product or even software - or the computer program, the computer program product or even the software itself or stored in a storage device - which comprises a network of so-called nodes, whereby each node is generally connected to several other nodes. Furthermore, a neural network in the context of this description is understood to be, for example, a computer program product or software stored in a storage device which, when run on a computer, generates such a network in accordance with the present description. The nodes are also referred to, for example, as neurons, units or entities. Each node has at least one input and one output connection.Input nodes for a neural network are those nodes that can receive signals (data, stimuli, patterns, or similar) from the outside world. Output nodes of a neural network are those nodes that can pass on signals, data, or similar to the outside world. So-called "hidden nodes" are those nodes of a neural network that are neither input nor output nodes.

[0097] The neural network can, for example, be designed as a so-called deep neural network (DNN). Such a "deep neural network" is a neural network in which the network nodes are arranged in layers (whereby the layers themselves can be one-, two- or even higher-dimensional). A deep neural network comprises at least one so-called hidden layer, which only contains nodes that are not input nodes or output nodes. This means that the hidden layers have no connections to input signals or output signals.

[0098] So-called "deep learning", for example, refers to a class of machine learning techniques that utilize many layers of non-linear information processing for supervised or unsupervised feature extraction and transformation as well as for pattern analysis and classification.

[0099] The neural network can also have a so-called auto-encoder structure. Such an auto-encoder structure can be suitable, for example, for reducing the dimensionality of data and thus, for example, for identifying similarities and commonalities.

[0100] A neural network can, for example, also be designed as a so-called classification network, which is particularly suitable for classifying data into categories. Such classification networks are used, for example, in connection with handwriting recognition.

[0101] Another possible structure of a neural network can be, for example, the design as a so-called “deep-

[0102] Believe Network" .

[0103] A neural network can, for example, also comprise a combination of several of the aforementioned structures. For example, the architecture of the neural network can include an auto-encoder structure to reduce the dimensionality of the input data, which can then be further combined with another network structure, for example, to detect peculiarities and / or anomalies within the reduced data dimensionality or to classify the reduced data dimensionality.

[0104] The values ​​describing the individual nodes and their connections, including further values ​​describing a specific neural network, can be stored, for example, in a set of values ​​describing the neural network. Such a set of values ​​then represents, for example, a configuration of the neural network. If such a set of values ​​is stored after training of the neural network, then, for example, a configuration of a trained neural network is stored. For example, it is possible to train the neural network with corresponding training data in a first computer system, then store the corresponding set of values ​​assigned to this neural network, and transfer it to a second system as a configuration of the trained neural network.

[0105] Furthermore, software or a computer program that implements a neural network can also represent an embodiment of the neural network. A variant of such a computer program that is designed for both inference and training of this neural network represents a possible embodiment of this neural network, as does a variant of such a computer program that is designed, configured, and / or optimized only for inference of the neural network.

[0106] A neural network can generally be trained by using a variety of well-known learning methods, such as inputting input data into the neural network and analyzing the corresponding output data from the neural network to determine parameter values ​​for individual nodes or their connections. In this way, a neural network can be trained using known data, patterns, stimuli, or signals in a method that is generally known today, so that the trained network can then be used, for example, to analyze further data.

[0107] In general, the training of the neural network means that the data with which the neural network is trained is processed in the neural network with the help of one or more training algorithms in order to calculate or change so-called bias values, weight values ​​and / or transfer functions of the individual nodes of the neural network or the connections between two nodes within the neural network.

[0108] To train a neural network, e.g. according to the present description, one of the methods of so-called "supervised learning" can be used. In this case, a network is trained with corresponding training data in order to achieve results or skills associated with this data. Furthermore, a method of so-called unsupervised training can also be used to train the neural network. Such an algorithm creates a model for a given set of inputs, for example, which describes the inputs and enables predictions to be made from them. There are, for example, clustering methods with which the data can be divided into different categories if they differ from one another, for example due to characteristic patterns.

[0109] When training a neural network, supervised and unsupervised learning methods can also be combined, for example when parts of the data are assigned trainable properties or abilities, while another part of the data is not.

[0110] Furthermore, methods of so-called reinforcement learning can also be used for training the neural network, at least among other things.

[0111] For example, training, which requires a relatively high computing power of a corresponding computer, can take place on a high-performance system, while further work or data analyses with the trained neural network can then be carried out on a lower-performance system. Such further work and / or data analyses with the trained neural network can be carried out, for example, on an edge device and / or on a control device, a programmable logic controller, a modular programmable logic controller, or other corresponding devices according to the present description.

[0112] Machine learning and / or the supervision of a machine learning system work in two main phases: training and inference. Inference is the process of generating an output from the ML model by feeding new data into these artifacts / models to produce an output, while the new data was usually not used for training and / or setting up the ML model. E.g., machine learning inference is the ability of a machine learning system to make predictions from novel data. There are three key components needed for machine learning or supervision inference: a data source, a machine learning or supervision system to process the data, and a data target.

[0113] Training refers to the process of using a machine learning algorithm to build a model. Training involves using a deep learning framework (e.g., TensorFlow) and a training dataset. IoT data provides a source of training data that data scientists and engineers can use to train machine learning models for a variety of use cases, from fault detection to consumer intelligence.

[0114] Inference refers to the process of using a trained machine learning algorithm to make a prediction. IoT data can be used as input to a trained machine learning model, enabling predictions that can drive decision logic on the device, at the edge gateway, or elsewhere in the IoT system.

[0115] A trained neural network, or one set up for training, is essentially a relatively complex piece of software. However, the effort required to train the neural network is later far greater than what is needed to deploy the trained neural network. Therefore, it is often desirable to shed the "ballast" necessary for training if you want to use the trained neural network later.

[0116] While this is a brand new area of ​​the field of computer science, there are two main approaches to taking this giant neural network and modifying it for speed and improved latency in applications.

[0117] The first approach considers parts of the neural network that aren't activated after training. These sections are simply not needed and can be "cut away." The second approach looks for ways to merge multiple layers of the neural network into a single computational step.

[0118] The identification of the first surface area on the processed material web using the modified first measurement data can be carried out, for example, in such a way that similarities between the modified first measurement data and data acquired by the second acquisition device are recognized.

[0119] There are a variety of technically proven similarity methods for detecting similarities, for example, between 2D data structures such as images or similar. Examples of such similarity methods include so-called fingerprint methods such as "template matching" or "key-point matching." An overview of some such methods can be found, for example, in the aforementioned article "Integration of Traceability Systems in Battery Production" (Günther Riexinger et al., Procedia CIRP, Volume 93, 2020, pages 125-130, ISSN 2212-8271, https: / / doi.org / 10.1016 / j.procir.2020.04.002).

[0120] (https : / / www. sciencedirect . com / science / article / pii / S221282712 030531X) ) .

[0121] For example, the identification of the first surface area on the processed material web can be designed and configured such that, using the second detection device, different second measurement data are acquired with respect to different second surface areas of the processed material web, and each of these second measurement data is compared with the modified first measurement data. This comparison can be carried out, for example, using a similarity method, as explained above.

[0122] For example, the identification of the first surface area on the processed material web can be designed and configured such that the second surface area for which the acquired second measurement data has the highest similarity to the modified first measurement data is identified and / or recognized as the first surface area on the processed material web.

[0123] In alternative embodiments, a special marking on the material web, such as a printed character and / or pattern, a marking on the edge, ID information (e.g. a QR code or a bar code) or comparable identification features can also be used to identify the first surface area on the processed material web. Matching comparison methods for these special markings can then be used to identify the first surface area. In the context of the present description, a surface area is understood very generally to be a specific area of ​​the surface of the movable or moving material web. Each of the surface areas is assigned and / or can be assigned to a physically fixed location on the moving material web.In this case, the designation as first and / or second surface area according to the present description is correlated with the associated acquired first and / or second measurement data. As already explained above, a second surface area on the processed material web can, for example, correspond entirely or partially to a first surface area on the unprocessed material web, be part of such a surface area, overlap with it, or even extend beyond it—or a combination of the aforementioned cases.

[0124] In this way, for example, by recognizing the first surface area of ​​the unprocessed material webs on the processed material web, a location on the material web defined by the first surface area can be recognized and thus, for example, tracked through the process step during processing of the material web.

[0125] In an advantageous embodiment of the method, it can be provided that a location coordinate on the material web is assigned or can be assigned to the first surface region of the material web, wherein the location coordinate is designed and configured such that it describes a position of the first surface region at least in a longitudinal direction and / or transport direction of the material web.

[0126] In this way, a method according to the present description makes it possible to track a processing of the material web in a spatially resolved manner, in that the method enables recognition of a surface area after various process steps within the scope of the processing and thus the processing of the material web can be tracked specifically at the location coordinate defined by the surface area.

[0127] In a corresponding manner, the method described above can also be extended to the tracking of more than one surface area. When extended to the acquisition of measurement data on more than one surface area of ​​the unprocessed material webs, and then the subsequent recognition of these surface areas on the processed material web according to the method explained in the context of this description, the method described here enables the recognition and tracking of various precisely defined locations on the moving or movable material web through the process step.

[0128] The method can, for example, be designed and configured in such a way that, in order to identify a specific one of the above-mentioned more than one surface area on the processed material web, modified first measurement data are generated in accordance with the present description for all of the first measurement data recorded prior to processing of the material web for the respective surface areas. These are then compared, for example, with second measurement data recorded in the context of identifying a specific surface area on the processed material web, e.g. by means of a similarity or fingerprint method in accordance with the present description. If a similarity between this second measurement data and modified first measurement data relating to a specific one of the above-mentioned surface areas is identified, this surface area is then defined as recognized.

[0129] In an advantageous embodiment, it can be provided that when comparing the recorded second measurement data of the processed material web with the above-mentioned modified first measurement data, only those of the modified first measurement data are used for which no surface area on the processed material web has yet been identified.

[0130] In an even further development, it can then be provided that the identification of the first surface area and / or further first surface areas takes place only using those of the modified first measurement data for which no associated surface area on the processed material web has yet been identified.

[0131] These arrangements increase the efficiency of the procedure and / or reduce the effort by reducing the number of comparisons to be carried out.

[0132] In an extension of the described method, such a method can then also be extended, for example, to several process steps, even across several process steps. In this case, it can be provided that after each of the process steps the surface areas known before the process step are recognized or identified using a method according to the present description. It can also be provided that only after a selection of the process steps are previously known surface areas recognized or identified using a method according to the present description. In this way, an improved and / or simplified method is provided for tracking or tracing or tracing the effect of one or more process steps or processing steps on a moving and / or movable or an extended material web in a location-specific manner.

[0133] In this way, tracking or tracing of an extended material web during processing can be carried out with the process step with comparatively high spatial resolution.

[0134] In a further advantageous method, the above-mentioned method embodiments, the extension of the method to many surface areas and the further extension to many process steps, can also be combined in order to obtain tracking of a moving or movable material web over a complete process chain with high spatial resolution.

[0135] In an advantageous embodiment, it can be provided that the at least one process ML model is designed and configured in such a way that an application of the at least one process ML model to the first measurement data simulates or partially simulates a change in the first measurement data due to an effect of the process step on the first surface area or comprises such a simulation.

[0136] The process ML model, the first measurement data of the process step, and the simulation or partial simulation of the effect of a process step on the measurement data can be designed and configured according to the present description. Furthermore, it can be provided that the at least one process ML model is designed and configured as a process ML model that was trained using the following method steps:

[0137] - Acquisition of training data of a surface area of ​​a training material web,

[0138] - Processing the training material web or the surface area of ​​the training material web by the process step ,

[0139] - Acquisition of modified training data of the surface area,

[0140] - Training the process ML model using the training data and the modified training data,

[0141] - Saving the trained process ML model .

[0142] It can be provided that the process ML model is designed and set up as exactly one process ML model.

[0143] In an advantageous embodiment of a method for training a process ML model according to the present description, it can be provided that a separate recognition marking on the training material web is assigned to the surface area on the training material web from which the training data and the modified training data are acquired.

[0144] Such a recognition marking can, for example, be designed and configured in such a way that it can be reliably, or relatively reliably, recognized by a corresponding detection device and / or recognition device even after the training material web has been processed by a process step according to the present description. Such a recognition marking can, for example, be designed and configured as a graphic symbol, a QR code, a barcode, ID information, a color marking, an RFID tag, a magnetic material or comparable markings, or can comprise such markings.

[0145] Furthermore, it can be provided that relative position information with respect to such a recognition marking is assigned to the surface area.

[0146] In this way, the assignment of the training data to the modified training data can be made more precisely and thus the training process can be improved.

[0147] The training data can be acquired, for example, with a first acquisition device using first measurement parameters and a first measurement arrangement.

[0148] The acquisition of the modified training data can, for example, also be carried out with the first acquisition device using the first measurement parameters and the first measurement arrangement.

[0149] Furthermore, the acquisition of the modified training data can be carried out using the first acquisition device and using further measurement parameters and / or a further measurement arrangement.

[0150] The acquisition of the modified training data can also be carried out with a second acquisition device using second measurement parameters and / or a second measurement arrangement.

[0151] The training data can be designed and configured as measurement data according to the present description. The acquisition of the training data can be designed and configured as an acquisition of measurement data according to the present description.

[0152] The modified training data can also be designed and configured as measurement data according to the present description. The acquisition of the modified training data can also be designed and configured as an acquisition of measurement data according to the present description.

[0153] The training material web can be designed and configured as a material web according to the present description. A training material web can be any material web, even within the context of a corresponding production process. The term "training material web" used in the description of the training process for a process ML model serves only to clarify the present description.

[0154] The fact that an application of a process ML model for a process step to measurement data acquired with regard to a surface area of ​​a material web before the application of the process step simulates, or at least partially simulates, a change in the measurement data due to an effect of the process step on the surface area can be designed and configured such that the process ML model has been trained at least among other things by the above-mentioned method and / or a comparable method.

[0155] For example, a process ML model for a specific process step according to the present description and measurement data that were recorded before processing of the material web by the process step with regard to a surface area of ​​the material web are considered. The fact that the application of the process ML model to the recorded measurement data simulates a change in the measurement data due to an effect of the process step on the surface area, or at least partially simulates it or comprises such a simulation, can be designed and configured such that the process ML model was trained at least among other things by the above-mentioned method and / or a comparable method according to the present description.

[0156] The process ML model can, for example, be designed and configured as a neural network, e.g., a deep neural network. In this case, the neural network can be trained or have been trained, for example, using supervised learning according to the present description, according to a training method according to the present description.

[0157] In the above-mentioned case, it can be provided, for example, that a training method according to the present description is designed and configured in such a way that the training data is input into the ML model or neural network to be trained, and the neural network to be trained then outputs result data. The ML model or neural network is then trained by calculating deviations of the modified training data from the result data, and these deviations are used to train the ML model or neural network using methods for supervised learning that are known per se, as also briefly outlined elsewhere in this description.

[0158] Furthermore, it can be provided that the process step comprises several process sub-steps, that each of the process sub-steps is assigned a process ML model of the at least one process ML model, wherein each of the process ML models was trained using the following method steps:

[0159] - Acquisition of training data of a surface area of ​​a training material web,

[0160] - Processing the training material web or the surface area of ​​the training material web by the respective process sub-step,

[0161] - Acquisition of modified training data of the surface area,

[0162] - Training the process ML model assigned to the process sub-step using the training data and the modified training data,

[0163] - Saving the trained process ML model assigned to the process sub-step.

[0164] Each of the process sub-steps can be designed and configured as a process step according to the present description.

[0165] The training of each process ML model assigned to one of the process sub-steps is then carried out using a training procedure according to the present description.

[0166] This embodiment of the method enables the extension of a method for tracking surface areas of a material web to several processing steps of the material web and / or also detection steps of surface areas with several detection devices and / or detection parameters.

[0167] In an advantageous embodiment, it can be provided that a number of process ML models are generated for various processing or process steps according to the present description. This number of process ML models can then be stored, for example, in a process ML model database. For a very specific processing and measurement data acquisition relating to a material web, the appropriate process ML models can then be selected from the number of process ML models, and spatially resolved tracking can be started using a method according to the present description.

[0168] The training material web can be designed and configured as a material web according to the present description. A training material web can be any material web, even within the context of a corresponding production process. The term "training material web" used in the description of the training process for a process ML model serves only to clarify the present description.

[0169] The fact that an application of a process ML model for a process step to measurement data acquired with regard to a surface area of ​​a material web before the application of the process step simulates, or at least partially simulates, a change in the measurement data due to an effect of the process step on the surface area can be designed and configured in such a way that the process ML model has been trained by the above-mentioned method and / or a comparable method.

[0170] For example, a process ML model for a specific process step and measurement data that were recorded before the material web was processed by the process step with regard to a surface area of ​​the material web are considered. The fact that the application of the process ML model to the recorded measurement data simulates, or at least partially simulates, a change in the measurement data due to an effect of the process step on the surface area can be designed and configured such that the process ML model was trained by the above-mentioned method and / or a comparable method according to the present description.

[0171] The process ML model can, for example, be designed and configured as a neural network, e.g., a deep neural network. In this case, the neural network can be trained or have been trained, for example, using supervised learning according to the present description, according to a training method according to the present description.

[0172] In the above-mentioned case, it can be provided, for example, that a training method according to the present description is designed and configured in such a way that the training data is input into the ML model or neural network to be trained, and the neural network to be trained then outputs result data. The ML model or neural network is then trained by calculating deviations of the modified training data from the result data, and these deviations are used to train the ML model or neural network using methods for supervised learning that are known per se, as also briefly outlined elsewhere in this description.

[0173] The above-mentioned object is further achieved by a method for training a process ML model, wherein the process ML model is designed and configured such that an application of the process ML model to measurement data relating to a surface area of ​​a material web simulates or partially simulates a change in the measurement data due to an effect of a process step on the first surface area or comprises such a simulation, wherein the method comprises the following method steps:

[0174] - Acquisition of training data of a surface area of ​​a training material web,

[0175] - Processing the training material web or the surface area of ​​the training material web by the process step ,

[0176] - Acquisition of modified training data of the surface area,

[0177] - Training the process ML model using the training data and the modified training data,

[0178] - Saving the trained process ML model ( 172 ) .

[0179] The training data can be designed and configured as measurement data according to the present description. The acquisition of the training data can be designed and configured as an acquisition of measurement data according to the present description.

[0180] The modified training data can also be designed and configured as measurement data according to the present description. The acquisition of the modified training data can also be designed and configured as an acquisition of measurement data according to the present description.

[0181] The process ML model, the measurement data, the material web, the surface area, the simulation or partial simulation of a change in measurement data due to an effect of a process step on the one surface area and the training of the process ML model can be designed and configured according to the present description. The above-mentioned object is also achieved by a computer-readable storage medium, wherein the computer-readable storage medium comprises a process ML model, wherein the process ML model has been trained using a method according to the present description, and wherein the process ML model is designed and configured for use as a process ML model of the at least one process ML model in a method for tracking locations on a material web according to the present description.

[0182] The process ML model can, for example, be designed and configured in such a way that the execution of the process ML model with first measurement data on a computer results in the determination of modified first measurement data by applying the process ML model to the first measurement data.

[0183] The first measurement data, the computer, the determination of the modified first measurement data, the process ML model and the application of the process ML model to the first measurement data can be designed and configured according to the present description.

[0184] The above-mentioned object is further achieved by a system for tracking locations on a material web during the processing of the material web, wherein the system is designed and configured to carry out a method for tracking locations on a material web according to the present description, comprising: a first detection device for detecting the first measurement data of the first surface region of the material web, a second detection device for detecting second measurement data relating to surface regions of the processed material web, and a computing device which is designed and configured to apply the at least one process ML model to the first measurement data to generate the modified first measurement data, and further to identify the first surface region on the processed material web using the modified first measurement data (330) and the second measurement data.

[0185] In this case, the computing device can, for example, be designed and configured to compare the acquired measurement data relating to the surface areas of the processed material web with the modified first measurement data, as well as to identify the first surface area on the processed material web using the modified first measurement data in accordance with the present description.

[0186] The moving or movable material web, the processing of the material web, the detection devices, the surface areas of the material web, the first and second measurement data, the modified measurement data, the process ML model and the identification of the first surface area can be designed and configured according to the present description.

[0187] As already explained in the context of the present description, the identification of, for example, the first surface area on the processed material web can be carried out, for example, by comparing the second measurement data recorded with respect to surface areas on the processed material web with the modified first measurement data with respect to the first surface area - for example using a similarity method or fingerprint method. As already explained, the surface area of ​​the processed material web whose associated second measurement data is most similar to the modified first measurement data is then identified as the first surface area.

[0188] The moving or movable material web can, for example, be moved in a transport direction at a transport speed and / or a transport speed profile. For example, the material web can continue to be moved in one direction of movement.

[0189] The system in question makes it possible to track the effect of a material web in a spatially resolved manner during processing. One aim, for example, is to generate, set up, and / or calibrate a moving coordinate system for the material web by recognizing surface areas during processing of the material web, in order to, for example, monitor or be able to monitor the effect of the processing on the material web in a spatially resolved manner. Furthermore, other areas of the material web can be monitored and / or analyzed by interpolation between different surface areas under consideration.

[0190] As already explained above, the fact that the system mentioned is designed and configured to carry out a method according to the present description makes it possible to improve or increase the detection accuracy of surface areas, identification points and / or markings during the processing of material webs.

[0191] The computing device can be designed and configured, for example, as a computer, an EDGE device, a PLC, a virtual PLC, one or more modules of a PLC or virtual PLC, a control device, a cloud, an automation server, a control application in a cloud, or a comparable computing device, or can include such components. The computing device can also be designed and configured as a system comprising several of the aforementioned components, which are or can be communicatively coupled.

[0192] The computing device also includes the process ML model. The computing device also identifies the first surface area on the processed material web using the modified first measurement data and the second measurement data.

[0193] Furthermore, it can be provided that the process ML model is stored, provided, and / or configured in a sub-device of the computing device, for example, a module for a control device, a separate EDGE device, a cloud, or even another computing device according to the present description. Furthermore, it can be provided that the generation of the modified first measurement data according to the present description also takes place in this sub-device.

[0194] It can further be provided that training of such a process ML model either also takes place in one of the mentioned devices or also in another computing device according to the present description. In particular, it can be provided that training of a process ML model according to the present description takes place in a computing device with relatively high computing power, such as a computer, a workstation, a

[0195] server, a cloud, an EDGE device or a comparable computing device.

[0196] It can also be provided that the identification of the first surface area is carried out by a method according to the present description in the said sub-device of the computing device, or also in a further sub-device of the computing device, for example a module for a control device, a separate EDGE device, a cloud, or also in a further computing device according to the present description.

[0197] The computing device can, for example, have a memory area for storing measurement data, both measurement data of the material web before processing by the process step and measurement data after processing of the material web by the process step. Furthermore, the memory area, or another memory area, can also be provided and configured, for example, for storing recording times as well as process parameters and transport speeds. Furthermore, the computing device can be designed and configured to compare measurement data. Such a comparison can be carried out using comparison methods, fingerprint methods or identification methods known from the prior art. If the measurement data is designed and configured as image data, then image comparison methods or image recognition methods known from the prior art can be used, for example.

[0198] The control device can be any type of computer or computer system that is designed and configured to control a device, a machine, a system, an apparatus, a component, or a piece of equipment. The controller can also be a computer, a computer system, or a so-called cloud on which control software or a control software application, for example a control application, is implemented, instantiated, or installed. Such a control application implemented on a computer or in a cloud can, for example, be designed and configured as one or more applications with the functionality of a programmable logic controller.

[0199] The control device can also be designed and configured as a so-called edge device, wherein such an edge device can, for example, comprise an application for controlling devices or systems. For example, such an application can be designed and configured as an application with the functionality of a programmable logic controller. The edge device can, for example, be connected to another control device of a device or system or directly to a device or system to be controlled. Furthermore, the edge device can be designed and configured such that it is additionally connected to a data network or a cloud or is designed and configured to be connected to a corresponding data network or a corresponding cloud.

[0200] The control device can, for example, also be designed and configured as a so-called programmable logic controller (PLC). Furthermore, the control device can also be designed and configured as a so-called modular programmable logic controller (modular PLC).

[0201] The control device can comprise a control module or central module designed and configured to run a control program. The control module can, for example, comprise the functionality defined by the IEC 61131 standard.

[0202] The control module can, for example, also be designed and configured as a software application designed and configured for the real-time execution of a control program for controlling the processing component. The software application can, for example, include the functionality defined in the IEC 61131 and / or IEC 61499 standards.

[0203] The control module can also be designed and configured as a separate mechanical module or a separate assembly which is designed and configured for the real-time execution of a control program. Such a mechanical module or assembly can also comprise, for example, the functionality defined by the standard IEC 61131 and / or IEC 61499. For example, the control module can be designed and configured as a programmable logic controller itself or, for example, as a central module of a modular programmable logic controller. In this case, the control module can, for example, comprise the functionality of an input / output assembly or also not comprise any functionality of an input / output assembly.

[0204] A programmable logic controller, or PLC for short, is a component that is programmed and used to regulate or control a system or machine. Specific functions such as sequential control can be implemented in PLCs, allowing both the input and output signals of processes or machines to be controlled. Programmable logic controllers are defined, for example, in the IEC 61131 and / or IEC 61499 standards.

[0205] To connect a programmable logic controller to the system or machine, both actuators, which are generally connected to the outputs of the programmable logic controller, and sensors are used. Status displays are also used. The sensors are generally located at the PLC inputs; they provide the programmable logic controller with information about what is happening in the system or machine. Examples of sensors include: light barriers, limit switches, buttons, incremental encoders, level sensors, and temperature sensors. Examples of actuators include: contactors for switching on electric motors, electric valves for compressed air or hydraulics, drive control modules, motors, and drives.

[0206] A PLC can be implemented in various ways. This means it can be implemented as a standalone electronic device, as a software emulation, as a so-called "virtual PLC" or "soft PLC," as a PC plug-in card, etc. Modular solutions are also common, in which the PLC is assembled from several plug-in modules. Such modules can be, for example, a central control module, an input / output module, a communication module, a converter module, an application module, or similar modules.

[0207] A virtual PLC or a so-called soft PLC is a programmable logic controller which is implemented as a software application and can run or runs on a computer device, an industrial PC or other PC, a computing device, or e.g. an EDGE device. In this case too, it is possible to implement a virtual PLC or soft PLC in a modular way. In this case, individual functionalities of a programmable logic controller or PLC are designed as individual software modules which can be connected via so-called middleware. Such modules can, for example, be a central control software module (e.g.Which includes at least, among other things, the properties specified by the IEC 61131 standard), a communication module for coupling to a fieldbus, to certain devices or apparatus, to an Ethernet, an OPC-UA or comparable communication standards, a web server module, an HMI module (HMI: human machine interface) and / or an application module according to the present description.

[0208] A modular programmable logic controller can be designed and configured in such a way that a plurality of modules can be or are provided, wherein as a rule one or more expansion modules can be provided in addition to a so-called central module (also referred to as a central control module or CPU) which is designed and configured to run a control program, e.g. to control a component, machine or system (or part thereof). Such expansion modules can be designed and configured, for example, as a current / voltage supply or for the input and / or output of signals or also as a function module or application module for taking on special tasks (e.g. a counter, a converter, data processing with artificial intelligence methods (includes, for example, a neural network or another ML model).In the present case, for example, it can be provided that a process ML model is implemented in such a module for a programmable logic controller.

[0209] For example, a functional module or application module can also be designed and configured as an AI module for executing actions using artificial intelligence methods. Such a functional module can, for example, comprise a neural network or an ML model according to the present description or another ML model according to the present description.

[0210] An edge device can, for example, comprise an application for controlling devices or systems. For example, such an application can be designed and configured as an application with the functionality of a programmable logic controller. The edge device can, for example, be connected to another control device of a device or system or directly to a device or system to be controlled. Furthermore, the edge device can be designed and configured such that it is additionally connected to a data network or a cloud or is designed and configured to be connected to a corresponding data network or a corresponding cloud.

[0211] An edge device can also be designed and configured to implement additional functionalities related to, for example, the control of a machine, system, or component—or parts thereof. Such functionalities can include, for example:

[0212] - Collecting and transferring data to the cloud and / or appropriate pre-processing, compression and / or analysis of such data;

[0213] - Data analysis, e.g., using AI methods, e.g., neural networks or corresponding ML models. The edge device can, for example, include an ML model for this purpose;

[0214] - Managing or conducting training of a neural network or ML model. The training itself can take place at least partially on the edge device itself, or at least partly in a cloud. If training takes place in a cloud, the edge device can, for example, be configured to download the trained neural network or ML model and subsequently use it.

[0215] In the following, the present invention is presented and explained using the example of tracking (so-called "tracking" or "tracing" of production steps or processes) in electrode production within the framework of battery production.

[0216] In the production of battery cells, the production of battery electrodes is an important step. This electrode production consists of several separate, sequential steps in which large rolls of material, so-called "foil coils" (e.g., material webs of up to 4 km in length for aluminum or copper) are processed.

[0217] In a coating step, a coil of film is unwound, coated with electrode material, a so-called "slurry," and dried. The resulting coated film, also called an electrode web, is then wound into a new coil. This resulting coil is transferred to a calendering step, in which the coated film is pressed between the rollers. Each of these steps can consist of a sequence of unwinding, processing, and winding a coil.

[0218] In a subsequent longitudinal cut, the electrode web is cut lengthwise (longitudinally) into several webs of smaller width. Optionally, an additional cut can also be made between coating and calendering. The resulting "daughter" coils with the coated, calendered and slit electrode web are fed to the cell assembly, where they are cut laterally into sheets (e.g., 20 cm long), stacked and placed in a container to protect them from environmental influences. Each battery cell consists of a multitude of electrode sheets. While it is easy to identify and track a cell as a standalone element (e.g., with a printed identifier such as a barcode), it is difficult to identify the origin of the electrode sheets on the continuous electrode web across the various process steps.

[0219] One of the topics considered in this description is the traceability of the electrode track at the sheet level across all production steps. For example, imagine the case where a battery cell is identified as defective during an end-of-line test. Knowing which sections of the electrode track the assembled layers of the cell originate from is an important factor for comprehensive root cause analysis and process optimization. However, in today's battery production facilities and / or gigafactories, corresponding tracking and / or tracing still takes place at the level of slurry batches and coil IDs, which allows only very rough conclusions about a specific cell.

[0220] For such traceability, markers (e.g., barcodes) can be used that are printed / lasered or applied to the film. However, the following problems may arise under certain circumstances:

[0221] - The markers can affect product quality, (2)

[0222] - it is difficult to find a suitable location for the markers because most of the uncoated edges of the film are removed in subsequent process steps and the positions of the remaining notches are not known in advance. ( 3 )

[0223] - Additionally, these notches are used as current collectors and surface contamination can impair this main functionality of the tabs.

[0224] For such tracing, at least among other things, so-called "visual fingerprinting" can be used to identify and compare images of electrode tracks.

[0225] A limitation of such known approaches is the following: They assume that images of the same trajectory region, obtained from two separate process steps, are sufficiently similar to produce the same fingerprint. Otherwise, the accuracy of the matching deteriorates (missed matches and false alarms).

[0226] For example, winding and unwinding the coil can change the visual appearance of the surface. This can particularly affect the beginning of the web, where the coil radius is small, the curvature is high, and the layers on the coil receive pressure from the upper layers. For example, a disturbance or prominent structure on the surface can create an imprint on adjacent layers of the coil, which can subsequently impair visual recognition.

[0227] A method according to the present description can also be carried out using a visual fingerprint or other fingerprint (in this case the detection devices would be designed as cameras, for example, and the measurement data would be images captured with them). In this case, a so-called "key-point approach" and / or a so-called "template matching approach" can be pursued. In a key-point approach, specific key points are first detected (e.g. specific inhomogeneities in the gray values). These are then described by feature vectors, which are finally used to find matching key points in image pairs. Existing methods such as ORB (oriented BRIEF), key-point detector and descriptor extractor or ASLFeat can be used for key-point-based image matching. Alternatively, there are already approaches for template matching, e.g. based on the Fast Fourier Transform ( FFT ) in OpenCV .Less common, but also well known, are approaches that only fit the phase part of the FFT (without considering the amplitude), which can be advantageous by focusing only on structural similarities between the images and reducing the effects of brightness variations.

[0228] An example of a visual fingerprint based on template matching is shown in Figure 2 and is explained in more detail below.

[0229] A method according to the present description may, for example, comprise one or more of the following improvements:

[0230] - Merging image-based fingerprinting with a physical model of the web,

[0231] - Use of a probabilistic model of plausible matches (based on distances) to reduce false positive matches,

[0232] - Use of probabilistic modelling of uncertainties in distances,

[0233] - Faster search by considering monotonicity constraints.

[0234] Visual fingerprinting, regardless of whether template matching or keypoint descriptors are used, frequently yields so-called "false positives." These so-called "false positives" are scan windows s of the processed material web that incorrectly match an incorrect window w of the unprocessed material web (see Figure 2). Reasons for false alarms can include ambiguities in the visual fingerprints, e.g., due to imperfect images (regarding size, resolution, lighting conditions, noise), and the need to use rather low detection thresholds to achieve sufficient identification of surface areas.

[0235] False positive results can be filtered, for example, as follows: Each window is assigned a longitudinal position (in meters) on the track. The position can be calculated from a timestamp of the corresponding image and a meter counter, the latter of which can also be derived from the speed of the moving electrode track integrated over time. The longitudinal distances between the windows are calculated based on these positions.

[0236] Implausible matches are those whose distance does not correspond to the expected value of the other matches. The decision as to which matches are plausible can be based on a weighted majority vote, where the weights are derived from the confidences of the matches (e.g. based on the correlation coefficients). Alternatively, the decision can be made iteratively, e.g. using Random Sample Consensus (RANSAC), a well-known technique in computer vision. In a further version of this embodiment, the distances can be represented as probability density functions, which explicitly describes the uncertainty of the values. For example, the timestamps of the camera images can have an uncertainty of 50 ms. At a line speed of 80 m / min, this means an uncertainty of almost 7 cm in the position.Calculating the distance between two positions further increases the uncertainty. This is especially true if we consider the probability density functions of two positions as normal distributions with variances o_l. A 2 and o_2 A 2, then the distance between them has a variance of o_l A 2+o_2 A 2 , which means that the individual variances add up. For a typical electrode plate length of, for example, 20 cm, the uncertainties can be large enough to become relevant in the physical model.

[0237] Another (independent) advantage of merging the visual fingerprint with a physical web model is that it reduces monotony on the web, and the resulting ordering of images can be used to speed up matching. Specifically, it exploits the fact that window positions on the web increase monotonically. Thus, instead of matching each scan window s against all windows w, only a subset of windows w needs to be considered. Windows w for which a stable consensus on a matching scan window s has already been reached can be excluded from the window set for all subsequent matches.

[0238] A special case with such processes are web breaks, where the web breaks unintentionally, e.g. due to improper tension control. When fixing a web break, a certain length of web is removed and the new ends are spliced ​​by hand. The length of the removed section is generally not recorded, so that the distances between the windows can be influenced. However, if a web break does occur, it is usually recorded / documented at least at the reel level (e.g. for quality control reasons) and its position can often be roughly estimated from control data. For the sections around a web break, path-related optimization can therefore be temporarily deactivated.

[0239] The present description relates in particular to an improvement of fingerprint methods known from the prior art, in which, for example, an AI-based image transformation model (image-image translation) for predicting process influences (e.g. winding, calendering) is used to improve the detection of matches between images across the production steps.

[0240] It is motivated by the fact that the surface of the electrode web can change due to process and / or machining steps, e.g., winding and / or unwinding. And, of course, the surface can also change significantly during calendering.

[0241] These changes can affect the matching accuracy or even make the matching impossible. For example, for the calender, it may be possible to circumvent the problem by taking the images before the calender, but this may require the installation of an additional vision system. However, the effects, for example, due to winding and / or unwinding, cannot be avoided. The basic idea is to create an ML model according to the present

[0242] Description, e.g. to train a deep neural network, to predict the effects on the surface. The training set can consist of pairs of images of the same area with and without the respective effect and a vector x of additional context information (e.g. position in partial counters on the web, product type). Examples of creating such training data to model the effect of winding and / or unwinding can be: acquiring an image taken before winding and unwinding (e.g. in the coating process directly after drying and before winding into a coil) and acquiring another image of the same area after unwinding. Another example to model the effect of calendering can be: acquiring an image taken before calendering and acquiring another image of the same area after calendering.

[0243] When creating such training sets, it can be helpful, for example, to use markers (e.g., stickers) to achieve high accuracy in the pixel-wise correspondences between the acquired images before and after the corresponding process step. A further increase in the accuracy of the training set can be achieved by considering pixel-wise shifts of the images to increase the correlation between the acquired images before and after the corresponding process step.

[0244] Based on such a training set, a corresponding ML model, e.g. a deep neural network (DNN), can then be trained to translate between images with and without a process or processing step. Already known approaches, such as pixßpix, can also be used for this. Such a trained ML model can then be used, for example, as described below using the example of Figure 3. Images w of the material web before the process step are fed to the model to predict the translated image w ', which predicts what the original image w looks like after the considered process step (e.g. after calendering). Then, w ' is used instead of w in the comparison described above. The overall scheme is shown in Figure 3.

[0245] The term "image" in this description generally refers to a 2D image, which can be generated by a line or area camera providing a grayscale or RGB image. In principle, however, an "image" can also be a hyperspectral camera image or be generated by a virtual measurement, e.g., 3D tomography.

[0246] Further advantageous embodiments can be found in the subclaims.

[0247] In the following, the invention is explained in more detail by way of example with reference to the accompanying drawing.

[0248] Figure 1 shows an example system for tracking locations on a moving or movable material web during pressing of the material web;

[0249] Figure 2 shows an exemplary strip section of the material web according to Figure 1 before and after pressing with exemplary scan areas;

[0250] Figure 3 shows an exemplary process sequence for an image comparison before and after pressing using an ML transformation of the image data before pressing. Figure 1 shows a processing station 140 for pressing a material web 120, 122, 124. The material web 120, 122, 124 is unwound from an unwinding roll 126 and moved at a constant speed v through the pressing station 140 to a take-up roll 128, where the material web 120, 122, 124 is rewound after pressing. In the pressing station 140, the material web is guided between an upper pressing roll 142 and a lower pressing roll 144. The pressing rollers 142, 144 and the material web 120, 122, 124 are arranged, designed, and configured such that the material web is pressed together or compressed. Such pressing steps occur, for example, in the production of electrodes for battery or accumulator cells, e.g.after applying and drying electrode material to a corresponding carrier layer. In the context of battery electrode production, such a process step is called "calendering."

[0251] Figure 1 does not show a complete material web section from the unwinding roll 126 to the winding roll 128, but rather the same material web section three times: once as the first image 120 of the material web section 120 immediately after unwinding from the unwinding roll 126, then as the second image 122 of the material web section 122 during the pressing of the material web 120, 122, 124, and then as the third image 124 of the material web section 124 shortly before the material web 120, 122, 124 is wound up. For the sake of ease of explanation, the respective reference symbol is used both for the respective image of the material web section in the figures and for the respective material web section itself.

[0252] Furthermore, Figure 1 shows a tracking system 110 for tracking the material web during its processing - e.g. for spatially resolved tracking of the effects of the pressing by the pressing station 140 on the material web 120, 122, 124.

[0253] The tracking system 110 comprises a first camera 150 with a first clock 152 (can also be designed and configured as a timer, clock or counter, for example), wherein the first camera 150 and the first clock 152 are designed and configured such that the clock 152 records the capture time 300 of each image 300 taken with the first camera 150 and this is then stored together with metadata 300, 310 stored for the image 300 and / or as metadata 300, 310 assigned to the image 300.

[0254] The tracking system 110 further comprises a second camera 160 with a second clock 162 (can e.g. also be designed and configured as a timer, clock or counter), wherein the second camera 160 and the second clock 162 are designed and configured such that the clock 162 records the capture time 400 of each image 400 taken with the second camera 160 and this is then stored together with metadata 400, 410 stored for the image 400 and / or also as metadata 400, 410 assigned to the image 400.

[0255] In the context of this description, in particular the description of the figures, it is assumed that captured images 300, 400 are captured, stored, and / or transmitted with the respective associated capture time 300, 400. This will not be mentioned separately in every case below.

[0256] The tracking system 110 also includes a computer 170, to which the first camera 150 transmits the images 300 it has captured, including the corresponding capture times 300. The second camera 160 also transmits the images 400 it has captured, along with the corresponding capture times 400, to this computer 170.

[0257] A further component of the tracking system 110 is a speed sensor 130 for the time-resolved detection of the speed of the material web 120, 122, 124. The speed data is then also transmitted to the computer 170, where it is stored as time-resolved speed data or a corresponding speed profile. The computer is then designed and configured, for example, to process and / or evaluate the speed data, such as smoothing, averaging, normalization, drift correction, or the like. To simplify the explanations of the process sequences shown in Figures 1 to 3, the following description of the figures for Figures 1 to 3 and the corresponding process descriptions assume a constant web speed v of the material web 120, 122, 124.

[0258] The computer 170 is designed and configured to carry out a so-called fingerprint method, for example by having appropriate software installed and / or running on it. The fingerprint system is designed and configured, for example, in such a way that, for example, before the material web 120, 122, 124 is processed, images of certain surface areas are captured and then, by means of a fingerprint method, recognition method or identification method known from the prior art, these surface areas are recognized by means of image comparisons of images of the material web 120, 122, 124 taken after the processing with the previously taken images. For this purpose, for example,At specific time intervals, images 300 of the material web 120 prior to pressing by the processing station 140 are taken together with the respective acquisition times 300 and then transmitted to the computer 170 together with the acquisition times 300. After the material web 122 has been processed by the processing station 140, images 400 of the material web 124 are then again taken by the second camera 160, again together with the corresponding acquisition times 400, which are then likewise transmitted back to the computer 170.

[0259] The computer 170 then compares the images 400 captured by the second camera with the images 300 taken by the first camera and, using a fingerprint method such as is known from the prior art, attempts to identify the respective image 300 taken by the first camera 150 from the images 400 taken by the second camera 160. In this way, the same surface areas or locations on the material web 120, 122, 124 can be identified and / or compared before and after processing, and thus, at least among other things, the effect of the processing on the respective surface areas can be tracked.

[0260] To carry out this fingerprint method for identifying surface areas wl after processing the material web 120, 122, 124 in the processing station 140, the computer 170 comprises a neural network 172. The neural network 170 is designed, configured, and trained in such a way that it simulates an effect of the processing of the material web 122 in the processing station 140 on images wl, w2, w3 of the unprocessed material web 120 captured by the first camera 150. For this purpose, the neural network 172 was trained with image pairs, each consisting of an image of a surface area before pressing taken by the first camera 150 and an image of the same surface area after pressing taken by the second camera 160. The neural network 172 is designed and configured as a deep neural network (DNN) known from the outset.The neural network 172 was trained using supervised learning methods known from the prior art for such deep neural networks (DNNs). However, other neural networks or ML models according to the prior art or the present description can also be trained and used for this purpose.

[0261] The fingerprinting process then proceeds in such a way that images 300 of surface areas w1, w2, w3 captured by the first camera 150 are input into the neural network 172. The neural network 172 then generates a modified image 330, which is then used for comparison with images of the material web 124 captured by the second camera 160 after pressing in the processing station 140.

[0262] This embodiment of the fingerprint method increases the probability of detecting surface regions of the material web 120, 122, 124 processed by the processing station, in that possible changes to the surface of the material web 120, 122, 124 caused by the processing have already been simulated and / or incorporated, at least partially, in the images 300 of the first camera 150 processed by the neural network 172. Images 330 generated in this way may then be more similar to the images 400 of the respective corresponding surface regions taken by the second camera and are therefore easier to detect using corresponding fingerprint methods.

[0263] This design of the fingerprint method will be discussed in more detail below in connection with Figure 3.

[0264] Furthermore, by recording the images 300 of the material web 120 with the first camera 150 before processing, for example, a length scale of the material web 120, 122, 124 can be defined. In this case, the procedure can be such that a surface area wl that is assigned to the first image wl, which was recorded by the first camera 150 at a first time immediately after the material web 120 has been unwound from the unwind roll 126, forms a zero point of such a material web length scale. From a known transport speed of the web and the respective capture times of the images wl, w2 by the first camera 150, the distance from one another of the surface areas wl, w2 assigned to these images wl, w2 can then be determined.In this way, each of the corresponding surface areas wl, w2 can be assigned a spatial longitudinal coordinate on the material web - and thus a length scale, in particular a virtual length scale, can be defined on the material web 120, 122, 124.

[0265] In the same way, after identifying the first image sl taken by the second camera 160, the surface area sl assigned to this image sl again represents the zero point of the material web defined above - this was thus "rediscovered" or "re-identified". By correspondingly recognizing the further surface areas s5, s9 by means of recognizing the images wl, w2 taken by the first camera 150 among the images sl - s9 taken by the second camera 160, the said (virtual) length scale on the material web 120, 122, 124 can then be reproduced after processing by the processing station 140 based on the known transport speed of the material web 120, 122, 124 and the corresponding recording time 400 of the second images 400.

[0266] In this way, for example, each surface area w1, w2, w3, s1, s5, s9 associated with a respective image taken by the first camera 150 and / or the second camera 160 can be assigned a corresponding longitudinal coordinate on the material web 120, 122, 124. At least among other things, this allows the effect of the processing by the processing station 140 on the material web 120, 122, 124 to be directly tracked with spatial resolution.

[0267] This longitudinal coordinate assigned to a specific surface area wl, w2, w3, sl, s5, s9 can also remain assigned to the surface area throughout the entire preceding and subsequent process chain until the production of one or more end products. This makes it possible, for example, to trace which longitudinal coordinates or longitudinal coordinate ranges of the material web were used in the product if an error or malfunction occurs. The stored process data and images can then be used to determine the possible causes of the error or malfunction.

[0268] In an advantageous embodiment, a spatial distance of a first surface area wl from a second, subsequent surface area w2, which distance is known according to the above description, can be used for the recognition of the second surface area w2 after successful identification of the first surface area wl. This can, for example, be designed and configured in such a way that after recognition of the first image wl or surface area wl, among the images sl - s9 taken by the second camera 160, preference is given to the image s5 of the processed material web 124 for recognition of the second surface area w2 which is at a time interval from the image wl of the first surface area wl taken by the second camera 160, which time interval results from the above-mentioned, known distance between the assigned surface areas and the transport speed of the material web.

[0269] If, for example, when comparing images sl - s9 taken by the second camera 160 with the second of the images w2 of the second surface area w2 taken by the first camera, different images s4, s5, s6 arise which have a certain similarity to the second image w2 taken by the first camera 150, then within the scope of the method that of the images s5 is selected in which the distance of the associated surface area s5 to the already identified first surface area sl is closest to the expected distance.

[0270] Furthermore, for example, a measurement uncertainty in the measurement of the times and the web speeds can be taken into account. This can be taken into account in the process, for example, by determining a distance probability distribution from the known distance between the first w1 and second surface area w2 as well as measurement uncertainties in the image acquisition and speed measurement of the material web. Such a probability distribution can, for example, be designed and configured as a Gaussian or similar probability distribution or be approximated by such a probability distribution.This probability distribution can then be used, for example, together with similarity values ​​which result from comparisons of images s1 - s9 taken by the second camera 160 with the second image w2 of the second surface area w2 taken by the first camera 150 according to fingerprint methods known from the prior art, to select the image s5 corresponding to the second surface area w2 from the second camera 160.

[0271] The reference symbols wl, w2 and sl - s9 introduced above are explained in more detail in the description of Figure 2.

[0272] Figure 2 shows the upper section of the material web section 120 after unwinding from the unwind roll 126 shown in Figure 1.

[0273] The reference symbols for the areas wl, w2, and w3 of the material web section 120 before processing each designate both the corresponding surface areas wl, w2, w3 and images wl, w2, w3 of these surface areas wl, w2, w3 captured, for example, by the first camera 150 shown in Figure 1. The reference symbols tl, t2, and t3 designate the respective capture times tl, t2, and t3 of the associated images wl, w2, w3, for example, with the first camera 150.

[0274] Furthermore, Figure 2 shows the same material web section 124 in the middle and lower sections as above, but this time after the processing of the material web section 122 and immediately before winding onto the take-up roll 128 shown in Figure 1. In Figure 2, an arrow v symbolizes a movement of the material web sections 120, 124 shown in Figure 2 in the direction of the arrow at a speed v. With a camera stationary with respect to Figure 2, the material web sections 120, 124 would therefore move under such a camera in the direction of the arrow shown.

[0275] Here too, the reference symbols for the areas sl, s2, s3, s4, s5, s6, s7, s8 and s9 (also abbreviated as sl - s9 in this description) of the material web section 124 after processing respectively designate both the corresponding surface areas sl, s2, s3, s4, s5, s6, s7, s8, s9 (abbreviated sl - s9) and images sl, s2, s3, s4, s5, s6, s7, s8, s9 (sl - s9) of these surface areas sl, s2, s3, s4, s5, s6, s7, s8, s9 (sl - s9) captured by the second camera 160 shown in Figure 1. The reference symbols TI, T2, T3, T4, T5, T6, T7, T8, T9 (TI - T9) denote the respective acquisition times TI, T2, T3, T4, T5, T6, T7, T8 and T9 (TI - T9) of the associated images sl, s2, s3, s4, s5, s6, s7, s8 and s9 (sl - s9) with the second camera 160.

[0276] The upper area in Figure 2 shows an area of ​​the material web 120 already shown in Figure 1 immediately after unwinding from the unwinding roll 130 and before processing in the processing station 140. On the material web 120, a first surface area w1 is shown on the left, a second surface area w2 in the middle and a third surface area w3 on the right on the material web 120.

[0277] In Figure 2, characteristic hatchings are assigned to the respective surface areas wl, w2, w3 of the unprocessed material web 120, which are characteristic both for a specific appearance of the respective surface area wl, w2, w3 and for the images wl, w2, w3 captured therefrom.

[0278] At the very bottom of Figure 2, a length scale is shown, which represents a longitudinal coordinate of regions of the material web 120, 124 along the material web. Based on this longitudinal scale, Figure 2 shows that the first surface region w1 has an initial coordinate x1, the second surface region w2 has an initial coordinate x3, and the third surface region w3 has a longitudinal coordinate x5 along the material web section 120, 124.

[0279] Now, before the processing of the material web section 120 in the processing station 140, an image wl of the first surface region wl is captured by the first camera 150 shown in Figure 1 at a time t1. At a time t2, an image w2 of the second surface region w2 is captured in the same way at time t2. In the same way, an image w3 of the third surface region w3 is captured by the first camera 150 at a time t3.

[0280] The distance of the first surface area wl from the second surface area w2 can then be calculated, for example, from a difference between the acquisition time t2 of the image w2 of the second surface area w2 and the acquisition time t1 of the image wl of the first surface area wl as well as the transport speed v of the material web section 120. In this way, the initial coordinates x3 of the second surface area w2 can be calculated from a known location coordinate x1 for the first surface area wl. Analogous to the procedure described above, the initial coordinates x5 of the third surface area w3 can then also be determined from the acquisition time t3 of the image w3 of the third surface area w3 and the acquisition time t2 of the image w2 of the previous surface area w2 as well as the transport speed v of the material web section 120.

[0281] To simplify the following explanation, it is assumed that throughout the explanations of a method according to the present description, the material web is moved at a constant speed v .

[0282] It follows from this that, after the image acquisition explained above, before the processing of the material web 120 by the processing station 140, it is known after which time t2-t1 the acquisition of the image w2 of the second surface area w2 took place after the acquisition of the image wl of the first surface area wl. The distance x3-x1 of the second surface area w2 from the first surface area wl is therefore also known. Furthermore, it is also known after which time t3-t2 the acquisition of the image w3 of the third surface area w3 takes place after the acquisition of the image w2 of the second surface area w2. Here, too, the distance x5-x3 of the third surface area w3 from the second surface area w2 is likewise known.

[0283] Based on the material web section 124 shown in the middle area of ​​Figure 2 after its processing, a first variant of a tracking method for identifying or recognizing the above-explained surface areas w1, w2, w3 on the material web section 124 processed in the processing station 140 is described below.

[0284] In this case, images sl - s9 of respectively assigned surface areas sl - s9 on the processed material web section 124 are recorded in temporal succession by the second camera 160 mentioned with reference to Figure 1, with corresponding recording times TI - T9.

[0285] In general terms, the images sl - s9 of the processed material web section 124 are then compared with the images of the unprocessed material web section 120 transformed by the neural network 172 using a fingerprint method according to the prior art. The second camera 160 records images with a different image format than the first camera 150. Therefore, in the illustration in Figure 2, the images sl - s9 recorded by it have a different image format than the images wl, w2, w3 recorded by the first camera 150.

[0286] The results of these comparisons are symbolized in Figure 2 by corresponding hatching of the respective images sl - s9 of the processed material web 124. For example, a matching hatching of the first sl and seventh surface area s7 of the processed material web 124 or of the first sl and seventh image s7 of these surface areas sl, s7 shows that both images sl, s7 have a similarity to the image of the first surface area wl of the unprocessed material web 120 transformed by the neural network 172.The same applies to a similarity of the fifth s5 and eighth image s8 of the processed material web 124 to the image of the second surface area w2 of the unprocessed material web 120 transformed by the neural network 172, and also to a similarity of the third s3 and ninth image s9 of the processed material web 124 to the image of the third surface area w3 of the unprocessed material web w3 transformed by the neural network 172. For surface areas s2, s4, s6 on the processed material web 124, which do not have any hatching in Figure 2, no similarity was found with the images of the unprocessed material web 120 transformed by the neural network 172 used for comparison.

[0287] For this purpose, in a first step, the images sl - s9 of the processed material web 124 are then compared with the image of the first surface area wl of the unprocessed material web 120 transformed by the neural network 172 using a fingerprint method according to the prior art. In this process, a similarity is determined between the image of the first surface area wl of the unprocessed material web 120 transformed by the neural network 172 and the image sl acquired at time T1 as well as the image s7 of the processed material web 124 acquired at time T7. Furthermore, the distance between the first surface area wl on the unprocessed material web 120 and previous surface areas not shown in Figure 2 is known.By comparing the detection times TI and T7 with this known distance, taking into account the transport speed v, only the surface area sl of the processed material web 124 detected by the first image sl can correspond to the first surface area wl of the unprocessed material web 120. From the associated detection time TI, a detection time of the previous image not shown in Figure 2 and the transport speed v of the material web 120, 122, 124, a location coordinate x2 of the surface area sl on the processed material web 124 corresponding to the first surface area wl on the unprocessed material web can now be determined.

[0288] In a second step, the images s1 - s9 of the processed material web 124 are compared with the image w2 of the second surface area w2 of the unprocessed material web 120. In doing so, a similarity between the image w2 of the second surface area w2 of the unprocessed material web 120 and the image s5 acquired at time T5 and with the image s8 on the processed material web 124 acquired at time T8 is determined. Furthermore, the distance between the second surface area w2 on the unprocessed material web 120 and the preceding first surface area w1 is known. By comparing the acquisition times T5 and T7 with this known distance, taking into account the transport speed v, only the surface area s5 of the processed material web 124 acquired by the fifth image s5 can correspond to the second surface area w2 of the unprocessed material web 120.From the associated acquisition time T5, the acquisition time TI of the image sl and the transport speed v of the material web 120, 122, 124, a location coordinate x4 of the surface area s5 on the processed material web 124 corresponding to the second surface area w2 on the unprocessed material web 120 can now be determined.

[0289] In an analogous manner, it is then also determined that the surface area s 9 of the processed material web 124 captured by the ninth image s 9 corresponds to the third surface area w3 of the unprocessed material web 120. In the above-mentioned manner, a location coordinate x6 of the surface area s 9 on the processed material web 124 corresponding to the third surface area w3 on the unprocessed material web 120 is then also determined.

[0290] Based on the material web section 124 shown in the lower part of Figure 2 after pressing, a further variant of the tracking method explained above for identifying or recognizing the surface areas w1, w2, w3 explained above on the material web section 124 after pressing in the processing station 140 is described below.

[0291] In contrast to the method mentioned above, the images s1 - s9 of the processed material web 124 are only compared with those of the images taken from the unprocessed material web 120 and transformed by the neural network 172, which have not yet been identified by previous comparison steps.

[0292] This is illustrated in Figure 2 in such a way that some of the surface areas sl - s9 shown in the lower area of ​​Figure 2 or images of the surface areas sl - s9 no longer have any hatching compared to the example shown in the middle area of ​​Figure 2. The reason for this is that the images of the already identified surface areas wl, w2, w3 of the unprocessed material web 120 corresponding to this hatching, transformed by the neural network 172, were no longer used for comparison with the images sl - s9 of the processed material web 124.

[0293] For example, to examine the second to ninth images s2 - s9 of the processed material web 124, only the images of the second and third surface areas w2, w3 of the unprocessed material web 120 transformed by the neural network 172 are used. The reason for this is that the first surface area w1 of the unprocessed material web 120 has already been detected or identified on the processed material web, and the corresponding structure can therefore no longer occur in the subsequent images s2 - s9 of the processed material web.

[0294] And to examine the sixth to ninth images s6-s9 of the processed material web 124, for example, only the image of the third surface area w3 of the unprocessed material web 120 transformed by the neural network 172 is used. This is because the first and second surface areas w1, w2 of the unprocessed material web 120 have already been recognized or identified, and the corresponding structures can no longer appear in the subsequent images s6-s9.

[0295] In Figure 2, this can be seen, for example, in the fact that the seventh and eighth images s7, s8 in the lower area of ​​Figure 2 no longer have any hatching, whereas the corresponding images s7, s8 in the middle area of ​​Figure 2 still have hatching. The reason for this is that when examining the seventh and eighth images s7, s8, the first and second surface areas w1, w2 of the unprocessed material web had already been identified. Therefore, to subsequently examine the surface areas s6 - s9, only the image of the third surface area w3 of the unprocessed material web 120, transformed by the neural network 172, was used. And with this image, no further similarities could be found when examining, for example, the aforementioned seventh and eighth images s7, s8 of the processed material web 124.

[0296] Figure 3 shows an example of a method flow according to the present description using a process ML model 172 designed as a neural network 172 according to the present description.

[0297] In this case, the neural network 172 already shown with reference to Figure 1 and implemented in the computer 170 is used to take into account, approximate or simulate - or at least partially simulate or approximate - an influence of the processing of the material web 120, 122, 124 on images wl, w2, w3 taken of the surface areas wl, w2, w3 of the unprocessed material web 120.

[0298] As already explained above, the neural network 172 was trained with image pairs, each consisting of an image of a specific surface area taken by the first camera 150 before pressing and an image of the same surface area taken by the second camera 160 after pressing, using a training method for supervised learning known from the prior art. Furthermore, the neural network 172 is designed and configured as a "deep neural network" (DNN).

[0299] In the advantageous embodiment mentioned, the neural network 172 and, for example, also each process ML model 172 according to the present description can additionally be designed and set up in such a way that the aforementioned image pairs were each created using different process conditions, such as, for example, process parameters, measuring positions, material web speeds, temperatures and / or product properties. Furthermore, the aforementioned process conditions or parts thereof can also be or have been part of the training data. In this case, the neural network 172 or each process ML model 172 according to the present description can then further be designed and set up in such a way that the input data into the neural network 172 orProcess ML model 172, in addition to corresponding image data, process conditions according to the present description with regard to the processing step of the material web are used.

[0300] The left-hand area of ​​Figure 3 shows the method sequence for image capture of the unprocessed material web 120, as was explained, for example, in connection with Figures 1 and / or 2. In a first method step 300, one or more images w are captured of the unprocessed material web 120, together with capture times of the respective images w. Parallel to this, and / or before or after this, process data are determined in a further method step 310, such as process data relating to the processing step, a position of a camera, a surface area or similar positions, a material web speed and / or a product identifier.

[0301] Using the neural network 172 already mentioned above, an image transformation of the images w acquired in the first method step 300 is then carried out in a next method step 320 using the neural network 172. In this case, both the image data of the acquired images w and, at least optionally, the aforementioned process data, and possibly also the acquisition times, are input to the neural network 172 as input data.

[0302] The output data of the neural network 172 then consists of transformed images w', which simulate the effect of the process step on the images w' acquired from the unprocessed material web 120. These transformed images w' are then stored, together with the associated acquisition times and, if applicable, also the aforementioned process conditions, in a data storage device 340, for example, the computer 170, another computer, or a corresponding storage device 340.

[0303] The right-hand area of ​​Figure 3 shows a further data acquisition step after the processing of the material web 124 by the processing station 140 according to Figure 1. In this case, images s and associated acquisition times are again acquired of the processed material web 124 using the second camera 160 shown in Figure 1 in a method step 400. Furthermore, in a method step 410, corresponding process data of the processing by the processing station are again acquired and / or stored. These images and acquisition times can then also be stored in a corresponding storage device (not shown in Figure 3).

[0304] In a further method step 460 shown below in Figure 3, the transformed images w' of the unprocessed material web 120 stored in the data memory 340 are then compared with the images s acquired from the processed material web 124. This comparison can be carried out, for example, by fingerprinting or a similar known identification method according to the present description.

[0305] Furthermore, in a method step 450, a physical model of the material web is also used to identify the images w ' taken of the unprocessed material web 120 and transformed by the images es acquired from the processed material web 124. For example, known locations and distances of surface areas acquired on the unprocessed material web 120 are used in order to better identify these surface areas on the processed material web 124. This method can also be designed and configured, for example, according to the present description.

[0306] The result of this matching or comparison according to method step 460, taking into account the physical model 450, is then a localization of the surface areas recorded on the unprocessed material web 120 on the processed material web 124. This localization can also be designed and configured, for example, according to the present description.

Claims

Patent claims 1. A method for tracking locations (wl, w2, w3) on a material web (120, 122, 124) during processing of the material web (120, 122, 124), comprising the steps: - Acquiring first measurement data (300) of a first surface area (wl) of the material web (120), - processing the material web (122) in one process step, - Determining modified first measurement data by applying at least one process ML model (172) to the first measurement data (300) and identifying the first surface area (sl) on the processed material web (124) using the modified first measurement data.

2. Method according to claim 1, characterized in that the at least one process ML model (172) is designed and configured such that an application of the at least one process ML model (172) to the first measurement data (300) simulates or partially simulates a change in the first measurement data (300) due to an effect of the process step on the first surface area (wl) or comprises such a simulation.

3. Method according to one of claims 1 or 2, characterized in that the at least one process ML model (172) is designed and configured as a process ML model (172) which was trained using the following method steps: Acquiring training data (300) of a surface area (wl) of a training material web (120, 122, 124), Processing the training material web (120, 122, 124) or the surface area (wl) of the training material web (120, 122, 124) by the process step, Acquiring modified training data (400) of the surface area (sl), Training the process ML model (172) using the training data (300) and the modified training data (400), Saving the trained process ML model (172).

4. Method according to one of claims 1 or 2, characterized in that the process step comprises several process sub-steps, that each of the process sub-steps is assigned a process ML model of the at least one process ML model (172), wherein each of the process ML models was trained using the following method steps: Acquiring training data (300) of a surface area (wl) of a training material web (120, 122, 124), Processing the training material web (120, 122, 124) or the surface area (wl) of the training material web (120, 122, 124) by the respective process sub-step, Acquiring modified training data (400) of the surface area (sl), Training the process ML model assigned to the process sub-step using the training data (300) and the modified training data (400), Saving the trained process ML model assigned to the process sub-step.

5. A method for training a process ML model (172), wherein the process ML model (172) is designed and configured such that an application of the process ML model (172) to measurement data (300) relating to a surface area (wl) of a material web (120, 122, 124) a change in the measurement data (300) due to an effect of a process step on the first surface area (wl) is simulated or partially simulated or comprises such a simulation, characterized by the following method steps: Acquiring training data (300) of a surface area (wl, w2, w3) of a training material web (120, 122, 124), Processing the training material web (120, 122, 124) or the surface area (wl, w2, w3) of the training material web by the process step, Acquiring modified training data (400) of the surface area (wl, w2, w3), Training the process ML model (172) using the training data (300) and the modified training data (400), Storing the trained process ML model (172) .

6. A computer-readable storage medium, wherein the computer-readable storage medium comprises a process ML model (172), wherein the process ML model (172) has been trained according to claim 5, and wherein the process ML model (172) is designed and configured for use as a process ML model (172) of the at least one process ML model (172) in a method according to one of claims 1 to 4.

7. System (110) for tracking locations (wl, w2, w3) on a material web (120, 122, 124) during the processing of the material web (120, 122, 124), wherein the system (110) is designed and configured to carry out a method according to one of claims 1 to 5, comprising: a first detection device (150) for detecting the first measurement data (300) of the first surface area (wl, w2, w3) of the material web, a second acquisition device (160) for acquiring second measurement data (400) relating to surface regions (sl-s9) of the processed material web (124), and a computing device which is designed and configured to apply the at least one process ML model (172) to the first measurement data (300) to generate the modified first measurement data (330), and further to identify the first surface region (sl) on the processed material web (124) using the modified first measurement data (330) and the second measurement data (400).

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