Determination of the transition phase for converting different dynamic laser beam shapes in a laser cutting machine

Abstract

In one aspect, the present invention relates to a control unit (100) for providing control instructions (ci) for controlling a laser cutting machine (L) by determining transition phases for converting different dynamic laser beam shapes of the laser cutting machine (L), wherein the laser cutting machine (L) preferably comprises a dynamic laser beam shaping module (DBSM) for dynamically changing the laser beam shape. The control unit (100) comprises: a cutting plan interface (101) for receiving a cutting plan to be processed for cutting out parts of a workpiece, wherein each part is defined by a cutting profile comprising cutting segments sorted in a queue; an assignment tool (102) configured to assign a specific dynamic laser beam shape from a set of dynamic laser beam shapes to each cutting segment in the queue of cutting segments according to predefined evaluation criteria; a transition tool (104) for determining the transition phases between every two consecutive specific dynamic laser beam shapes, wherein within a transition time (t), a first specific dynamic laser beam shape among two consecutive specific dynamic laser beam shapes is converted into a second specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes; a processor (P) configured to iteratively access the assignment tool (102) for determining a specific dynamic laser beam shape for each cutting segment in the queue of cutting segments, and wherein the processor (P) is further configured to access the transition tool (104) for determining all transition phases between every two consecutive specific dynamic laser beam shapes, and wherein the processor (P) is configured to provide control instructions (ci) for controlling the laser cutting machine (L) for executing the received cutting plan by applying: 1. the specific dynamic laser beam shape determined by the assignment tool (102), and 2. the transition phases between every two consecutive specific dynamic laser beam shapes determined by the transition tool (104).

Description

[0001] Description

[0002] The present invention relates to laser cutting by means of a laser cutting machine which is provided with at least one optical module for dynamically changing the shape of a laser beam, such as a dynamic laser beam shaping module. In particular, the present invention relates to a method, a control unit and a computer program for determining a transition phase for transforming different dynamic laser beam shapes during laser cutting.

[0003] In laser cutting applications, high quality and performance are key factors therein.

[0004] Generally, the laser cutting process can be optimized for opposite requirements such as productivity and quality in particular. The higher the feed rate of the laser cutting head, the higher the productivity, but the quality may decrease because the laser beam acts on the material with a specific energy distribution which is defined by, for example, the spot size, the laser beam shape and the laser power. The key factor for cutting is to convert the absorbed laser energy into heat to melt the material. The energy coupling is determined by many factors and interacts, for example, with the cutting conditions of the cut.

[0005] To optimize the above requirements, in the prior art, it is known to influence the beam profile by, for example, changing the intensity distribution, the spot size, the laser beam shape and the focal position. The first option for obtaining such a modification presents static beam shaping (SBS) mainly by spatial methods. By using SBS, the laser beam is provided before the start of the process and cannot be changed any more. The second option is to modify the laser beam with dynamic characteristics. In this case, the characteristics of the laser beam can change during the process by dynamic laser beam shaping (DBS). Alternatively, some spatial modulation methods can also be performed dynamically, for example, by adaptive optics. In this regard, it is called "Dynamic beam shaping for thick sheet metal cutting", Cindy Goppold, Thomas Pinder, Patrick Herwig, IWS, in: Lasers in Manufacturing Conference 2017.

[0006] When using DBS, key challenges are addressed through the spatio-temporal distribution of laser energy on the material surface: sufficient cut size at a reduced spot size to obtain the available laser energy. For this purpose, the high laser energy of the small spot size oscillates periodically and is superimposed with the feed rate. As a result, the energy is distributed around the cut of the resulting cut and thus acts as an artificial larger spot. At this time, the cut width expands, enabling unhindered melt ejection. In addition, this distribution prevents heat accumulation because the interaction time of the laser beam with the material is reduced.

[0007] To apply DBS, a laser cutting machine is equipped with a dynamic laser beam shaping module. Example embodiments with such DBS applications are described in WO 2019145 536A1.

[0008] From US2010 / 0059490 A1, it is known to rapidly modify a laser processing beam and in particular its spatial intensity distribution.

[0009] The object of the present invention is to improve the quality of the cutting result and enhance flexibility when applying dynamic laser beam shaping.

[0010] This object is achieved by the appended independent claims. Other preferred embodiments and features are mentioned in the dependent claims and the following description.

[0011] According to a first aspect, the present invention relates to a computer-implemented method for determining a transition phase for converting different dynamic laser beam shapes for laser cutting by means of a laser cutting machine. The laser cutting machine includes at least one optical module for dynamically changing the shape of the laser beam, and the at least one optical module can be implemented, for example, as a dynamic laser beam shaping module. The method can at least include the following method steps:

[0012] - Receive a cutting plan to be processed for cutting out parts of a workpiece, where each part is defined by a cutting profile including cutting segments sorted in a queue;

[0013] - Provide an assignment tool configured to assign a specific dynamic laser beam shape from a set of dynamic laser beam shapes to each cutting segment in the queue of cutting segments according to predefined assignment criteria;

[0014] - Iteratively access the assignment tool to determine the specific dynamic laser beam shape for each cutting segment in the queue of cutting segments;

[0015] - Provide a transition tool that is used to determine the transition phase between every two (previously determined) consecutive specific dynamic laser beam shapes, wherein, within a transition time (t), the first specific dynamic laser beam shape among two consecutive specific dynamic laser beam shapes is converted into the second specific dynamic laser beam shape among two consecutive specific dynamic laser beam shapes; the transition time (t) is not equal to "0", and in particular, the transition time is greater than 0 ms. The transition time can be in the range between 0.05 ms and 10,000 ms. The transition time is a time phase for providing a smooth transition between two consecutive transition zones.

[0016] - The access transition tool is used to determine all transition phases between every two consecutive specific dynamic laser beam shapes;

[0017] - Provide control instructions with the determined transition phases for controlling a laser cutting machine to execute a received cutting plan by applying the following:

[0018] - For the specific dynamic laser beam shape of each cutting segment in the queue of cutting segments, which has been determined by an allocation tool,

[0019] - For the determined transition phases between every two consecutive specific dynamic laser beam shapes of each cutting segment of all parts to be cut according to the received cutting plan, wherein,

[0020] The transition phase has been determined by the transition tool.

[0021] With this method and solution according to the present invention, the contour error is further minimized and the cutting quality is enhanced because there will be no hard switching from one dynamic laser beam shape to the next or consecutive dynamic laser beam shape. The transition between different dynamic laser beam shapes is smoothed and improved. Therefore, the enhanced cutting quality includes enhanced smoothness of the cutting edge, minimization of burrs (adhesion of the melt near the cutting edge), minimization of discharged melt particles, and minimization of the risk of laser beam tearing during cutting.

[0022] In a preferred embodiment, the transition can be calculated by an algorithm, especially speed-related.

[0023] The transition time (duration of the transition) can be automatically determined or calculated by means of a transition time algorithm. The transition time algorithm can be configured to determine the time for the transition between two consecutive segments and / or the applied dynamic laser beam shapes. The transition algorithm can be configured to calculate the transition time between two corresponding consecutive segments depending on transition parameters and depending on the material properties of the material to be cut such as material type and / or material thickness, the transition parameters being selected from the group consisting of the types of Lissajous figures before and after the transition zone, the cutting speeds of two consecutive segments, and / or the type of cutting segment.

[0024] Iteratively, for each segment one segment after another, the assignment of the dynamic laser beam shape for the segment is performed by the assignment tool. The assignment is preferably segment-specific. Different types of segments (e.g., curves or straight lines) will be assigned different dynamic laser beam shapes.

[0025] In a preferred embodiment, the method may further include an intermediate verification step. After the assignment (segment - dynamic laser beam shape) has been calculated by the processor, for verification purposes, the assignment may be provided on the user interface. In the case where a verification signal is detected, the calculated assignment may be applied. Otherwise, corrective measures may be initiated. The corrective measures may be implemented as an offline algorithm (offline may mean, for example, independent of the cutting program and / or not during the cutting program) for calculating another (optimized) assignment. Alternatively or additionally, the corrective measures may be implemented as an online algorithm (online may mean, for example, during the cutting program). The "another (optimized) assignment" may be determined manually by the user via a manual input on the user interface, and / or may be determined algorithmically by, for example, considering historical data or statistical evaluations (such as averages) of other assignments.

[0026] Generally, a laser cutting machine may include more than one optical model, which contributes to or enables the dynamic variation of the laser beam. For example, two (2) galvanometer scanner mirrors may be used, one for movement along X and one for movement along Y. Alternatively or additionally, 3D beam shaping may be achieved by means of a 2-axis module for X / Y variation and / or a Z wobbling module for movement in the direction of the beam axis. Alternatively or additionally, a CIVAN laser system may be used to shape the beam by, for example, the interconnection of 32 single-light modules.

[0027] According to a preferred embodiment, the cutting segments are selected from the group comprising:

[0028] - Straight lines;

[0029] - Circles or circular segments with a configurable specific radius;

[0030] - Angles with a configurable specific angle;

[0031] - Parameterized curves;

[0032] - Penetration;

[0033] - Introduction;

[0034] - Extraction and / or

[0035] - Engraving.

[0036] According to another preferred embodiment, the dispensing tool and / or the transition tool (these terms will be defined later in the text) may include or may have access to a trained model, in particular a neural network model. The neural network may be, for example, a convolutional neural network (CNN).

[0037] The neural network has been trained to determine a transition phase for transitioning the dynamic laser beam shape between two consecutive cutting segments. For example, for segment i and segment i+1, the neural network or machine learning model is trained to provide a transition phase for transitioning the dynamic laser beam between segment i and segment i+1. The trained neural network model may be stored, for example, on a cloud-based server that exchanges data with the control unit.

[0038] (Deep) machine learning algorithms are data- and computation-intensive and are therefore preferably computed on a graphics processing unit (GPU) or a tensor processing unit (TPU) or a network of processors. Each layer of the neural network may be computed on a powerful massively parallel processor, in particular a multi-core or many-core processor. The computing unit is preferably designed as or includes a graphics card or the other hardware modules mentioned above.

[0039] The machine learning model may preferably be trained to identify the transition phase without prior analysis of attributes (or feature - feature extraction), which attributes / features (in particular which spatial and / or temporal attributes) of the first and second cutting segments are relevant for the determination of the transition phase.

[0040] Alternatively or additionally, a featureless extractor (or featureless) algorithm can be applied. This means that a so-called end-to-end algorithm can be implemented. "End-to-end" in this context means that the raw data, i.e., the acquired transition phases, can be used without substantial preprocessing and, in particular, without manually determining the features in the cut segments and their processing, which are then further processed (e.g., classified) into results using machine learning algorithms (also abbreviated as ML algorithms hereinafter). "Without significant preprocessing" in this context means except for marginal preprocessing such as histogram equalization, image depth reduction, and / or region of interest (ROI) cropping. In particular, the end-to-end approach does not require separate preprocessing of the raw data to extract "features" important for learning. Compared to classical ML methods with prior feature extraction, in the solution proposed here, not only is the classifier trained by the algorithm, but preferably the feature extractor is also trained in the same step. This means that the algorithm independently calculates or learns the representation from the input data (cut segments) and thus also calculates or learns "features". In order to identify this relationship, the algorithm must independently find the best representation of the input data in order to classify it. The fact that characteristic values ("features") do not have to be extracted in the preferred embodiment of the present invention is preferred in several respects. First, the effort of algorithm development can be simplified because important features do not have to be detected, determined, and extracted.

[0041] Furthermore, it is preferred that as the "featureless" algorithm is developed, there is no risk that the most important features containing the most information may be overlooked. Finally, the basic information is usually also contained in very complex, superimposed, or difficult-to-understand signal, image, or cut sequence feature representations, which makes optimal feature analysis difficult. Therefore, it is not surprising that the deep learning method implemented here outperforms feature extractor-based methods without any feature extraction.

[0042] The neural network can already be trained with a training algorithm based on annotated or partially annotated training data, which includes the evaluation of the cutting results with the applied transition phases. The training algorithm can be a supervised learning method or a semi-supervised learning method. The training algorithm can be based on historical data. Reinforcement learning methods can also be used to update or adjust the model. Reinforcement learning makes it possible to find a solution to this complex problem without (prior) knowledge and initial data about the laser cutting process and transition phases. In addition, reinforcement learning eliminates the need for time-consuming training data collection and processing.

[0043] To map the transition phases to a sequence of cut segments, a CNN or a deep neural network (DNN) can be applied. Alternatively or additionally, a so-called gated recurrent unit (GRU) or a long short-term memory network (LSTM) can be applied, especially in combination with a CNN to learn time-related features.

[0044] According to another preferred embodiment, the transition tool includes an evaluation tool, wherein the evaluation tool is configured to evaluate the specific dynamic laser beam shape and / or transition phase determined and applied manually and / or automatically by a sensing automatic evaluation unit using a user interface to provide an evaluation data set. The sensing automatic evaluation unit may include an optical system in the process, in particular a camera device and / or a set of diodes. In addition, the two can be combined so that two modes (automatic and manual modes) can be used as a verification step, which can be provided as a semi-automatic mode. Thus, for example, first, the sensing automatic evaluation unit can automatically provide a first evaluation data set, which can be subjected to a verification step by manual input (via a human-machine interface). Based on the manual input, a second evaluation data set is generated. The second evaluation data set can be compared with the first evaluation data set, and if the deviation is above a preconfigured threshold, a warning message can be generated indicating that the evaluation can be further evaluated and / or verified.

[0045] According to another preferred embodiment, the evaluation data set includes a common configurable share for setting different evaluation criteria, wherein the different evaluation criteria include quality evaluation, performance evaluation, energy consumption evaluation and / or process stability evaluation, wherein the different evaluation criteria have interdependencies, and the interdependencies are modeled on the user interface selection buttons provided on the human-machine interface. The user interface selection buttons are configured so that inconsistent inputs are no longer possible. Thus, for example, if the user wants to enter the highest level for quality, and also the highest level for performance, and also the lowest level for energy consumption, this will be evaluated as inconsistent and rejected as an acceptable input. The user is required to enter the corrected values.

[0046] In another preferred embodiment, the transition phase for each two consecutive specific dynamic laser beam shapes is determined specifically for the type of material properties and / or the type of cutting machine. The type of material properties may include material type (type of material, such as steel, alloy, aluminum, etc.) and / or material thickness (e.g., for flat materials with a thickness between 0.1 mm and 100 mm).

[0047] In another preferred embodiment, the transition phase for each two consecutive specific dynamic laser beam shapes is determined depending on the speed and / or acceleration and / or jump of the laser cutting head and / or on the type of cutting segment and / or on the laser cutting process parameters, the laser cutting process parameters including dynamic limitations of the laser power and / or drive.

[0048] In another preferred embodiment, the transition phase is determined by generating a focal oscillation pattern by means of a spatiotemporal distribution of the laser energy in the focal plane and / or on the material surface, said spatiotemporal distribution being related to:

[0049] - Frequencies in the X and Y directions and preferably in the X, Y, and Z directions;

[0050] - Amplitudes in the X and Y directions and preferably in the X, Y, and Z directions; and / or

[0051] - Phase shifts in the Y direction compared to the X direction and preferably in the Y and Z directions compared to the X direction.

[0052] Alternatively or additionally, the dynamic laser beam shape is changed by oscillation (with respect to frequency and / or amplitude) of the focus in the X and Y directions, which can be combined with wobbling (in the Z direction) with a changing laser beam diameter.

[0053] Alternatively or additionally, profile errors can be determined (estimated and / or measured) and these determined profile errors can be compensated. Compensation of the profile errors can be performed by means of calculation of a corrected assignment. Measurement of the profile errors can be performed by means of, for example, a coaxial camera device.

[0054] Due to the previous measurements (c x(t) , c y (t)) in the X and Y directions for each position or time step, the profile deviation is known. There are at least two methods to compensate for profile errors (offset, DBS amplitude):

[0055] Method offset:

[0056] The profile error value is used as the offset value for the dynamic laser beam shape. Since the profile error varies with the part / time, each position / time step has a different offset value.

[0057] Example:

[0058] · The dynamic laser beam shape is a Lissajous figure LF_1

[0059]

[0060] · The Lissajous figure with profile error compensation is LF_2

[0061]

[0062] DBS amplitude:

[0063] Instead of using an offset, the amplitude of the dynamic laser beam shape can be adjusted with the part / time.

[0064] Example:

[0065]

[0066] In another preferred embodiment, when determining a transition phase between each two consecutive specific dynamic laser beam shapes, in which a first specific dynamic laser beam shape of the two consecutive specific dynamic laser beam shapes is converted into a second specific dynamic laser beam shape of the two consecutive specific dynamic laser beam shapes, a transfer function f is applied, which transfers the first specific dynamic laser beam shape of the two consecutive specific dynamic laser beam shapes into the second specific dynamic laser beam shape, wherein the transfer function f converts the frequency, amplitude and / or phase shift of the first dynamic laser beam shape. In yet another preferred embodiment, the transfer function f can be linear, high-order exponential, triangular or logarithmic.

[0067] In another preferred embodiment, a transition tool for determining the transition phase between each two consecutive specific dynamic laser beam shapes is configured to determine the transition phase between each two consecutive specific dynamic laser beam shapes that are different from each other. Typically, according to the definition, the first cutting segment is different from the second continuous cutting segment. For example, the first cutting segment can be a straight line segment, and the second segment can be an angular segment with a curve. In this case, the first cutting segment is different from the second cutting segment. However, the queue of cutting segments can be defined differently, so that the first cutting segment can be a first type, and the second cutting segment can be the same (first) type. In the latter case, there is no need to access the transition tool, so that the transition phase between two identical or similar continuous cutting segments will not be calculated in order to reduce computing resource consumption. The definition of the cutting segments can be configured with the help of user input in the previous configuration stage. The similarity of the cutting segments can be defined according to a predefined scheme. For example, a straight line segment with slightly different angles followed by another straight line segment can be judged to be similar. A threshold value can be defined in the preparation stage of the method.

[0068] So far, the invention has been described with respect to the claimed method. Features, advantages or alternative embodiments herein may be assigned to other claimed objects (e.g. a computer program or a control unit) and vice versa. In other words, the device or apparatus may be improved with features described or claimed in the context of the method, and vice versa. In this case, the functional features of the method are implemented by structural units of the device or apparatus or system, respectively, and vice versa. Usually, in computer science, a software implementation and a corresponding hardware implementation (e.g. as an embedded system) are equivalent. Thus, for example, a method step for "receiving" data (e.g. a cutting plan) may be performed with an interface and corresponding instructions for receiving the data. To avoid redundancy, although the device may also be used in the alternative embodiments described with reference to the method, these embodiments are not explicitly described again for this device.

[0069] According to another aspect, the above object is solved by a control unit for providing control instructions for controlling a laser cutting machine by determining transition phases for transitioning between different dynamic laser beam shapes of the laser cutting machine, the laser cutting machine including at least one optical module for dynamically varying the shape of a laser beam, which in a preferred embodiment may be implemented as a dynamic laser beam shaping module. The control unit is configured to perform the method as described above. The control unit may include:

[0070] - A cutting plan interface for receiving a cutting plan to be processed for cutting parts of a workpiece, wherein each part is defined by a cutting profile including cutting segments sorted in a queue;

[0071] - An assignment tool configured to assign a specific dynamic laser beam shape from a set of dynamic laser beam shapes to each cutting segment in the queue of cutting segments according to predefined evaluation criteria;

[0072] - A transition tool for determining the transition phase between every two consecutive specific dynamic laser beam shapes, wherein during a transition time, a first specific dynamic laser beam shape among two consecutive specific dynamic laser beam shapes is converted into a second specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes;

[0073] - A processor configured to iteratively access the assignment tool to determine a specific dynamic laser beam shape for each cutting segment in the queue of cutting segments, and wherein the processor is further configured to access the transition tool to determine all transition phases between every two consecutive specific dynamic laser beam shapes, and wherein the processor is configured to provide control instructions for controlling the laser cutting machine to execute the received cutting plan by applying:

[0074] - A specific dynamic laser beam shape for each cutting segment in the queue of cutting segments, the specific dynamic laser beam shape having been determined by the assignment tool,

[0075] - The determined transition phases between every two consecutive specific dynamic laser beam shapes for each cutting segment of all parts to be cut according to the received cutting plan, wherein,

[0076] The transition phases have been determined by the transition tool.

[0077] In another aspect, the invention relates to a computer program including computer program code which, when executed by a processor, causes the processor to perform the steps of the method as described above.

[0078] In another aspect, the present invention relates to a computer-readable storage medium having stored therein the computer program as described above.

[0079] Hereinafter, the terms used in this application are defined.

[0080] At least one optical module is configured to facilitate and / or dynamically change the laser beam. The at least one optical module may include a dynamic laser beam shaping module. The dynamic laser beam shaping module is configured to dynamically change the shape of the laser beam during cutting of a contour according to a cutting plan. The dynamic laser beam shaping module may apply oscillation and / or dynamic laser beam shaping. The dynamic laser beam shaping module may also be configured to utilize a combination of the aforementioned options, i.e., a combination of variable laser beam diameter with oscillation of the focus position and DBS parameters (X-axis, Y-axis).

[0081] The cutting segments are usually provided as a queue or an ordered series of cutting segments. The cutting segments are ordered, for example, the first cutting segment precedes the second cutting segment, the second cutting segment precedes the third cutting segment, etc. The cutting segments and / or the queue of cutting segments can be defined in the cutting plan or can be calculated based on the data in the cutting plan. The queue is moved over the surface of the workpiece to be cut, in particular based on the cutting direction of the laser cutting head. Depending on the cutting plan to be executed, the cutting segments represent different types of cuts in the geometric structure. The cutting segments can be, for example, straight lines, curves with varying radii (parametric curves), which can represent corners, circles or circle segments, penetrations, introductions, extractions and / or engravings.

[0082] A transition phase will be interpreted as a spatial and / or temporal phase for converting a first specific dynamic laser beam shape into a continuous second specific dynamic laser beam shape for two consecutive cutting segments in a queue of cutting segments. A transition phase refers to a transition between two different types of segments and / or two different dynamic laser beam shapes applied. The transition phase can be represented as a transition zone or pattern. The transition phase can be configured so that a smooth transition between the respective two consecutive specific dynamic laser beam shapes is provided by defining the transition between the two segments by the cutting speed. Along a straight line with maximum cutting speed, for example a horseshoe shape is considered to best meet user-defined performance criteria. The slower the cutting speed, the more rounded the dynamic laser beam shape is considered to be the best. Different phases of transition can be provided, such as a dynamic laser beam shape at full speed, a dynamic laser beam shape in a corner at zero speed, and dynamic laser beam shapes in between. Further examples are provided in the detailed description.

[0083] The workpiece can be a metal workpiece. The workpiece can be a sheet workpiece or a tube workpiece. The workpiece can be, for example, metal sheets of different types and / or with different thicknesses. Generally, the cutting plan defines the parts that need to be cut out from the workpiece. The parts to be cut out from the workpiece can have a specific profile, which may vary depending on the part. For example, a first set of circular parts needs to be completely cut out from the workpiece, and a second set of rectangular parts needs to be cut out. Each part to be cut out can be defined by a cutting profile. The cutting profile can include one or more cutting segments. For example, a rectangular part can include a first segment as a first straight segment, followed by a second segment as a corner segment (radius), followed by a third segment as a second straight segment, followed by a fourth segment as a corner segment, followed by a fifth segment as the first straight segment again, and so on. The cutting profile defines the shape of the part from a top view.

[0084] The queue of cutting segments is defined by the moving direction of the cutting head. The queue is an ordered list of cutting segments that are cut one after another.

[0085] For each cutting segment, a specific dynamic laser beam shape is defined, and the solution proposed in this article focuses on determining the transition zones between these cutting segments. For all cutting segments and transition zones, cutting parameters need to be defined:

[0086] · The focal position of the laser beam

[0087] · Laser

[0088] ο Power

[0089] ο Frequency

[0090] ο Pulse width

[0091] · Feed rate (desired cutting speed)

[0092] · Cutting speed (depending on the dynamic capabilities and geometry of the moving axes)

[0093] · Nozzle distance

[0094] · Nozzle type and diameter

[0095] · Air pressure

[0096] · DBS parameters (deflection in the X and Y directions)

[0097] ο In the X direction

[0098] - Frequency

[0099] - Amplitude

[0100] ο In the Y direction

[0101] - Frequency

[0102] - Amplitude

[0103] Phase shift

[0104] Focus position swing along the Z direction

[0105] -frequency

[0106] -Amplitude.

[0107] Laser cutting machines are configured to apply a laser beam to a workpiece to thermally separate the workpiece material through laser radiation. The workpiece can be a tube or a flat sheet, with cutting lengths up to 12 meters and widths of 2 to 3 meters. Laser cutting machines can also be configured for 3D metal sheets, such as tubes or curved parts.

[0108] The laser cutting machine is equipped with at least one optical module. The laser cutting machine can, for example, include a dynamic laser beam shaping module, which can include, for example, laser scanner optics (such as those described in WO2019145536A1) or lens optics, which are actuated or oscillated in the x and y directions perpendicular to the laser beam axis (such as those described in WO2019 / 145536 A1). The technical purpose of the dynamic laser beam shaping (module) DBSM is to improve quality and / or performance. In one aspect, the DBSM can be used to provide energy over a larger area on the workpiece. In particular, for a wider cut width of the cut (which makes subsequent part automation / categorization easier), a higher amplitude dynamic laser beam shape and / or a different focal position can be selected and used to enlarge the spot size. In addition, due to the shorter interaction time with the high-power laser (less heat accumulation), the DBSM is used to provide less damage to the material properties, which is a major improvement. In terms of quality improvement: Among the standard cutting parameters (focal position, laser power, air pressure...), using an additional dynamic laser beam shape allows the corresponding selection of cutting and dynamic laser beam shaping parameters to achieve better quality and / or performance in the case of a higher dimensionality of the parameter space. In addition, due to the ability to change the dynamic laser beam shape, there is no need for a compromise setting for straight lines and corners, so the overall quality (also in corners and transitions) and / or performance can be improved. Preferably, the dynamic laser beam shape is adjusted during the transition phase (e.g., related to the cutting speed). The dynamic beam shaping can be applied at different beam shaping frequencies. The beam shaping frequency can be in the range between 100 Hz and one or more megahertz, and preferably in the range between 100 Hz and 900 kHz or between 100 Hz and several hundred kilohertz. Preferably, the beam shaping frequency can vary in each of the above directions, i.e., along X and Y, and even along the Z direction. It must be noted that in the preferred embodiment, the beam shaping frequency can be set differently in each of these directions, such that, for example, a first beam shaping frequency of 200 Hz can be applied along the X direction, and a second beam shaping frequency of 900 kHz can be used along the Y direction. The beam shaping frequency settings for each direction can be set and configured independently of each other on the user interface.

[0109] Alternatively, or in addition to varying the beam shaping frequency as described above, the laser pulse frequency can also be varied. The laser pulse frequency can be varied between 0 kHz and 5 kHz. Typically, laser pulse frequency is used only for specific applications, such as engraving, pulse cutting (e.g., when penetrating, curves, corners), so that the energy input can be adjusted by the pulses. In one aspect, varying the pulse frequency of the laser beam can be used to reduce the energy to be delivered to the workpiece. The laser pulse frequency setting can be configured on a human-machine interface (HMI). The HMI can provide settings for configuring the beam shaping frequency for each direction, as well as additional settings for configuring the laser pulse frequency, either in combination or separately.

[0110] The distribution tool and / or transition tool is an electronic module or a software module implemented in a hardware module with a processor, or a hardware module (e.g., an FPGA or ASIC, as described below). In the context of the present invention, "processor" can be understood to mean, for example, a machine or an electronic circuit. Specifically, the processor can be a central processing unit (CPU), a microprocessor, or a microcontroller, such as an application-specific integrated circuit or a digital signal processor, which may be combined with a memory unit for storing program instructions, etc. The processor can also be, for example, an IC (integrated circuit), in particular an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit), or a multi-chip module (e.g., a 2.5D or 3D multi-chip module) in which several so-called die are connected to each other directly or via interposers, or a DSP (digital signal processor) or a GPU (graphics processing unit). The processor can also be a virtualized processor, a virtual machine, or a soft CPU. It can also be, for example, a programmable processor equipped with configuration steps for performing the method according to the present invention, or configured with configuration steps in a manner that enables the programmable processor to implement the features of the method, component, module, or other aspects and / or partial aspects of the present invention, such as an FPGA or ASIC. The dispensing tool and / or the transition tool may be part of a controller for controlling the laser cutting machine, or may be a separate module in data connection with the controller.

[0111] The assignment tool can be configured to assign a specific dynamic laser beam shape for a specific cutting segment. In a simple form, the assignment tool can be provided as a table data structure with a set of entries that can be accessed using a specific cutting segment to infer an associated dynamic laser beam shape, and vice versa.

[0112] The allocation step can be extended by applying a rule-based association algorithm. The rules of the association algorithm can be stored in a rule memory of the allocation tool and / or in another external memory that can be accessed by the allocation tool via a network connection. In a very abstract, general, and simplified manner, the rules can be, for example, of the following form:

[0113] - Segment 1 - Shape 1 (short for dynamic laser beam shape 1)

[0114] - Segment 2 - Shape 2

[0115] - Segment 3 - Shape 3

[0116] - Segment 4 - Shape 1

[0117] - Segment 5 - Shape 3

[0118] - Segment 6 - Shape 4

[0119] - and so on, wherein a segment is defined by its type. The type may be selected from the group consisting of line, circle (segment), angle, parametric curve, penetration, lead-in, lead-out and / or engraving.

[0120] The rule can be modified independently of the execution of the method for determining the transition phase for a dynamic laser beam shape.

[0121] The correlation algorithm may be configured to take into account geometric data of a particular segment and / or a cutting speed set for a particular segment.

[0122] The transition tool can be configured to define the transition phase between two consecutive specific dynamic laser beam shapes. Along a straight line with maximum cutting speed, a horseshoe shape is considered to best meet user-defined performance criteria. A more rounded dynamic laser beam shape is considered best at slower cutting speeds. Different phases of transition can be provided, such as a dynamic laser beam shape at full speed, a dynamic laser beam shape in a corner at zero speed, and dynamic laser beam shapes with configurable speeds in between.

[0123] The transition phase is the switch from a first specific dynamic laser beam shape to a next specific dynamic laser beam shape.The transition parameters can be defined in terms of a transfer function.

[0124] The transfer function can be selected from a catalog or a set of functions, which can be configured in the preparation phase and even modified during the operation phase of the laser machine. The transfer function can be selected from a database of stored transfer functions. The transfer function can be defined, for example, according to a transfer function catalog.

[0125] For each section of the part, an optimal laser beam shape is defined. Depending on the path velocity and / or acceleration and / or jerk, each transition phase in all transition phases between two adjacent sections is proposed. Any combination of velocity, acceleration, and jerk correlations is possible. The transition phase can also be determined depending only on the velocity.

[0126] Alternatively or cumulatively, the transition phase can be determined by an algorithm.

[0127] Alternatively or cumulatively, the transition phase can be determined by means of an algorithm configured to depend on the type of cutting sections before and after the transition phase, material properties (e.g., material type and / or material thickness), and / or the type of Lissajous figure to determine the transition phase.

[0128] The corresponding laser beam shape can be represented, for example, by a Lissajous figure.

[0129] The first Lissajous figure (LF) is given by

[0130]

[0131] where the deflection x1 is along the X direction and the deflection y1 is along the Y direction. For the deflection along the X direction, the amplitude A1 and frequency a1 are used together with the time shift φ1. The same applies to the Y direction.

[0132] The second subsequent LF is given by

[0133]

[0134] For simplicity, only velocity-dependent transitions are shown below. The LF in the transition zone depends on the cutting velocity LF t (v c ). The linear transition is defined by

[0135]

[0136] where F represents the feed rate (desired cutting velocity).

[0137] The velocity-dependent transition can also have a higher-order exponent e p :

[0138]

[0139] Triangular correlations are possible. For example, a velocity-dependent transition with an exponent e p :

[0140]

[0141] Similarly, transition functions can be formulated for acceleration or jerk dependence:

[0142] Acceleration related:

[0143]

[0144] The maximum absolute value of acceleration is

[0145] Jump related:

[0146]

[0147] The maximum absolute value of the jump is

[0148] The method is not limited to using only one single correlation. Alternatively, a combination of speed, acceleration and / or jerk-related transitions is possible and may be preferred.

[0149] The evaluation tool is an electronic module. The evaluation tool can be a software module implemented in a hardware module having a processor, or can be a hardware module such as an FPGA or ASIC. The evaluation tool is configured to evaluate the determined and applied specific dynamic laser beam shape and / or transition phase manually by using a user interface and / or automatically by a sensory automatic evaluation unit to provide an evaluation data set representing the evaluation results.

[0150] In another aspect, the present invention relates to a computer program product comprising a computer program that can be loaded into a memory unit of a computing unit, the computer program comprising program code portions that cause the computing unit to perform a method for determining a transition phase as described above when the computer program is executed in said computing unit.

[0151] In another aspect, the present invention relates to a computer-readable medium on which program code portions of a computer program are stored or saved, said program code portions being loadable into a computing unit and / or executable in a computing unit, such that when the program code portions are executed in the computing unit, the computing unit carries out the method for determining a transition phase as described above.

[0152] The order in which the steps of the method of the present invention are described in this specification does not necessarily reflect the chronological order in which the steps are to be performed. For example, the steps of providing an allocation tool and providing a transition tool may be performed in another sequence.

[0153] According to the description and embodiments that will be described in detail in the context of the accompanying drawings, the features, characteristics, and advantages of the present invention described above, as well as the ways to achieve them, become clearer and easier to understand. The following description does not limit the present invention to the embodiments included. In different drawings, the same components or parts may be labeled with the same reference numerals. Generally, the drawings are not to scale. Description of the Drawings

[0154] Figure 1 is a schematic representation of the control unit of a programmable logic controller (PLC) for a laser cutting machine,

[0155] Figure 2 is a detailed schematic representation of a dispensing tool according to a preferred embodiment of the present invention;

[0156] Figure 3 is a detailed schematic representation of a transition tool according to a preferred embodiment of the present invention;

[0157] Figure 4 is a flowchart of a method according to a preferred embodiment of the present invention;

[0158] Figures 5a to 5c are three examples for acceleration-related dispensing or transition phases,

[0159] Figure 6 is another example for velocity-related dispensing or transition phases;

[0160] Figure 7 is another example for jerk-related dispensing or transition phases, and

[0161] Figure 8 is an exemplary representation of different cutting segments with assigned transition phases;

[0162] Figure 9 is an exemplary representation of the transition zone for a sharp corner segment. Detailed Description of the Invention

[0163] The present invention provides a tool for defining a transition zone for transitioning from one dynamic laser beam shape applied to a first cutting segment to the next dynamic laser beam shape for a subsequent cutting segment in a cutting sequence. The cutting segments can be, for example, "penetration", "straight line", "circle", "curve", "corner", etc.

[0164] The goal of the solution described herein is to define a smooth transition from one dynamic laser beam shape (e.g., Lissajous figure, etc.) to the next dynamic laser beam shape, with each dynamic laser beam shape being used for successive cutting segments in a cutting sequence.

[0165] A possible workflow can be:

[0166] 1) Load cutting plan

[0167] 2) Load setup data from database

[0168] a. Input performance criteria (user-defined weighting) via HMI;

[0169] b. Input / load material setup data (material type and thickness);

[0170] c. Input / load machine setup parameters (e.g., laser power, dynamic limits of drive);

[0171] d. Load / extract geometric characteristics of each segment (type and length of segment);

[0172] e. Load predefined dynamic laser beam shapes for each segment type in the cutting sequence;

[0173] f. Define and load transition zones between all different dynamic laser beam shapes;

[0174] 3) Execute cutting program according to cutting plan.

[0175] 4) Optionally: If required, evaluate and adjust transition zones based on performance criteria.

[0176] Figure 1 A control unit 100 is shown schematically for interacting with a programmable logic control PLC for controlling a laser cutting machine L.

[0177] The control unit 100 is configured to determine transition phases for switching between different dynamic laser beam shapes during or for laser cutting by means of the laser cutting machine L. The control unit 100 includes a processor P on which an assignment tool 102 and a transition tool 104 are implemented.

[0178] The laser machine L has a cutting head CH which includes at least one optical model, preferably a dynamic laser beam shaping module DBSM. Spatiotemporal beam oscillation can be achieved, for example, by a commercial high-dynamic 2D scanner unit which is ready to be integrated into the collimated beam path of the laser cutting head. Thus, the optical properties are not affected. The scanner can include two oscillating mirrors, each of which has a time-dependent position defined by a specific frequency and amplitude. The phase shift between the two mirrors is a fifth parameter for specifying the energy distribution. Control of the dynamic laser beam shaping module DBSM is performed by means of control instructions CI provided by the control unit 100.

[0179] The control unit 100 is further configured to receive a cutting plan via the cutting plan interface 101. Based on the received cutting plan, the control unit 100 is further configured to provide control instructions CI to be forwarded to the controller PLC of the laser cutting machine L. The laser cutting machine L is configured to cut a workpiece according to a predetermined cutting plan. For example, a number of parts can be cut out from the workpiece. The cutting is performed by moving the laser cutting head of the laser cutting machine L over the workpiece during the application of the laser beam. The laser cutting machine L can be equipped with a dynamic laser beam shaping module DBSM. The dynamic laser beam shaping module DBSM is configured to dynamically change the shape of the laser beam, for example, by oscillating the laser beam in an angular direction relative to the propagation direction of the laser beam.

[0180] The control unit 100 is preferably equipped with three different interfaces:

[0181] 1. First, the cutting plan interface 101, which is configured to receive a cutting plan,

[0182] 2. Second, the control interface 103, which is configured to transfer the calculated and provided control instructions CI to the controller PLC, and

[0183] 3. Third, the human-machine interface UI, which is configured to exchange data with the user. For example, intermediate results and final results can be provided on the human-machine interface UI. The intermediate results can relate to the determined specific dynamic laser beam shapes for each cutting segment in the queue of cutting segments and / or to the determined transition phases between each pair of consecutive dynamic laser beam shapes for each cutting segment of all the parts to be cut according to the received cutting plan. The final result can represent the control instructions CI.

[0184] The control unit 100 further includes an assignment tool 102 and a transition tool 104. The assignment tool 102 is configured to assign a specific dynamic laser beam shape from a (stored) set of dynamic laser beam shapes to each cutting segment in the queue of cutting segments according to predefined assignment criteria. The transition tool 104 is configured to determine the transition phase between every two consecutive specific dynamic laser beam shapes. Thus, within a specific transition time, the first specific dynamic laser beam shape among two consecutive specific dynamic laser beam shapes is converted into the second specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes.

[0185] In Figure 1 the exemplary embodiment shown, in addition to the controller PLC of the laser cutting machine L, a control unit 100 is provided as a separate module. For example, the control unit 100 can be deployed on a cloud-based server for data exchange with the local controller PLC of the laser cutting machine L. In an alternative embodiment, the control unit 100 can also be implemented directly on the controller PLC of the laser cutting machine L.

[0186] Figure 2 A more detailed representation of the allocation tool 102 is shown. The allocation tool 102 can be configured to execute an allocation algorithm in order to allocate a specific dynamic laser beam shape to each cutting segment according to predefined allocation criteria. The allocation algorithm can access a rule base with stored rules for determining the allocation under given requirements (allocation criteria). Alternatively or additionally, the allocation algorithm can be based on a trained machine learning model. The allocation tool includes: a first interface 102-1, which is configured to receive the allocation criteria; a second interface 102-2, which is configured to receive digital representations of the cutting segments (which are defined one after another in a queue of cutting segments (which are defined according to the contour to be cut according to the cutting plan)); and a third interface 102-3, which is configured to access a memory or database DB for storing a set of dynamic laser beam shapes. The memory can be implemented as a database. The allocation tool 102 also includes a fourth interface 102-4, which is used to provide the results of the allocation step, and in particular for providing a specific dynamic laser beam shape for a specific cutting segment. The allocation criteria may be defined by the allocation module and / or by manual input and / or by accessing a memory with stored allocation criteria.

[0187] Figure 3 A more detailed representation of the transition tool 104 is shown. The transition tool 104 comprises a first interface 104-1 for receiving a first or i-th and a corresponding consecutive second or i+1-th specific dynamic laser beam shape that has been provided by the allocation tool 102. Furthermore, the transition tool 104 comprises a second interface UI, which may be provided as a human-machine interface HMI. The second interface UI may be used to receive a manual evaluation data set representing a manual evaluation of the determined and applied specific dynamic laser beam shape and / or transition phase. The evaluation may be a quality evaluation, a performance evaluation, an energy consumption evaluation and / or a process stability evaluation. The second interface UI may also be used to provide the result of the automatic evaluation by means of using an automatic evaluation unit, which in Figure 3is depicted with reference to 104-2. The second interface UI can also be used to provide the calculated transition phase as an intermediate result for (user-based) verification purposes. The transition tool 104 also includes another interface, which serves as the result interface 104-3 and is configured to provide the determined transition phase as a final result. The transition tool 104 can also include a configuration tool 104-4, which is configured to provide determined configuration parameters for configuring the transition zone or the transition phase. For example, the configuration tool 104-4 can be used to determine whether the determination or calculation of the transition phase should be speed-related and / or acceleration-related and / or jerk-related. The configuration tool 104-4 can be provided as a software module that generates corresponding input fields on the human-machine interface to specify the evaluation by receiving numerical input or categorical input data.

[0188] Figure 4 A flowchart showing an embodiment of a method for determining a transition phase for converting different dynamic laser beam shapes for laser cutting is shown. After the method starts, in step S1, a cutting plan is received. In step S2, an allocation tool 102 is provided. In step S3, the allocation tool 102 is iteratively accessed to determine a specific dynamic laser beam shape for each cutting segment in the queue of cutting segments. In step S4, a transition tool 104 is provided. The transition tool 104 is configured to determine the transition phase between every two determined specific consecutive dynamic laser beam shapes, where the first specific dynamic laser beam shape among two consecutive specific dynamic laser beam shapes is converted into the second specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes. In step S5, the transition tool 104 is accessed to determine all transition phases between every two consecutive specific dynamic laser beam shapes. In step S6, a control instruction CI for controlling the laser cutting machine L is provided to execute the received cutting plan by applying: the determined specific dynamic laser beam shapes (determined by the allocation tool 102), and the transition phases for each cutting segment of all parts of the workpiece to be cut according to the cutting plan, where the transition phases have been determined by the transition tool 104. After that, the method can end or can be repeated (as Figure 4 shown by the dashed line in).

[0189] Figure 5a 、 Figure 5b and Figure 5c shows an acceleration-related determination of the transition phase between every two consecutive specific dynamic laser beam shapes. In Figure 5a the left side, the acceleration distribution of the cutting profile according to the cutting plan is depicted. In the X and Y planes, the positions in the X and Y directions are depicted, and the velocity is represented on the Z axis. In Figure 5aOn the right - hand side, the dynamic laser beam shape (here: circular) for a position on the contour is depicted, and this position is indicated by a star (in the upper - right corner of the cutting contour) in the acceleration distribution on the left - hand side. Generally, the matching of the cutting - contour segments (points) and the dynamic laser beam shape is provided by the assignment tool 102. Figure 5b shows the same acceleration distribution as Figure 5a shown, as well as another dynamic laser beam shape, which is shown on the right - hand side and has been assigned by the assignment tool 102. Figure 5c shows the same acceleration distribution as Figure 5a and Figure 5b shown, and yet another assigned dynamic laser beam shape, which is shown on the Figure 5c right - hand side and has also been assigned by the assignment tool 102.

[0190] Figure 6 shows another preferred embodiment of the present invention, in which the determination of the transition phase between every two consecutive specific dynamic laser beam shapes is performed according to the cutting speed of the laser cutting head, and the laser cutting head moves on the workpiece surface for cutting purposes. As can be seen on the Figure 6 left - hand side, the speed distribution for the same cutting contour as shown in FIG. 5 is depicted. On the Figure 6 right - hand side, a specific dynamic laser beam shape is depicted, which is assigned by the assignment tool 102 for a point in the cutting segment within the cutting contour, and this point is shown by a star (in the lower - left corner of the cutting contour) on the left - hand side.

[0191] Figure 7 Still shows another preferred embodiment of the present invention, in which the determination of the transition phase between every two consecutive specific dynamic laser beam shapes is performed depending on the jerk. Thus, on the Figure 7 left - hand side, the jerk distribution for the contour is depicted, and this contour is also the basis of FIG. 5 and Figure 6 . On the Figure 7 right - hand side, the assigned dynamic laser beam shape is depicted, and this assigned dynamic laser beam shape is assigned to the cutting segment that includes the "star" (upper - right corner of the contour) depicted on the Figure 7 left - hand side.

[0192] The parts have different geometric dimensions and shapes, which result in different conditions (e.g., cutting speed) for the laser cutting process. By dividing the geometry into different segments, the optimal laser beam shape can be found for each of these segments. For example, compared with straight segments that can usually be cut at a higher cutting speed, corner segments can have different cutting characteristics. The transition between segments will be performed in a smooth manner (continuous transition between segments). At least, the following segments are relevant:

[0193] - Straight line;

[0194] - A circle or circular segment with a configurable specific radius;

[0195] - An angle with a configurable specific angle;

[0196] - Parametric curve;

[0197] - Penetrate;

[0198] - Introduce;

[0199] - Lead out and / or

[0200] - Engrave.

[0201] Figure 8 An example cutting profile mainly having two different cutting segments and different transition zones or transition stages is shown. As can be seen in the Figure 8 example shown, the cutting profile includes a part of a circular element with a circular cut and a small circular cutting segment above the cut and to the upper right of the circular cutting profile. The transition zone is depicted with a left shading pattern in Figure 8 .

[0202] Reference numeral 81a depicts the "penetrate" cutting segment for the outer circular cutting profile. Reference numeral 81a2 represents the dynamic laser beam shaping transition zone or pattern from segment 81a to segment 82a. The latter segment 82a represents the "straight introduce" cutting segment. Reference numeral 82a3 depicts the dynamic laser beam shaping transition zone between segment 82a and segment 83. The latter segment 83 represents the "straight line" cutting segment, where the laser cutting head can move faster compared to the corner segment. Reference numeral 834 represents the dynamic laser beam shaping transition zone or stage between segment 83 and segment 84. Segment 84 is the "right turn corner" cutting segment. Reference numeral 845 represents the dynamic laser beam shaping transition zone or stage between segment 84 and segment 85. Segment 85 refers to another straight line cutting segment. Reference numeral 856 represents the dynamic laser beam shaping transition zone or stage between segment 85 and segment 86. Segment 86 represents the "left turn corner" cutting segment.

[0203] As can be seen in Figure 8 , the profile also includes another circular cutting segment, represented by reference numeral 87 in Figure 8 . This circular profile has a "penetrate" cutting segment, represented by reference numeral 81b in Figure 8 . The dynamic laser beam shaping transition zone between segment 81b and segment 82b is represented by reference numeral 81b2b in Figure 8 .

[0204] Figure 9A position-based diagram showing different dynamic laser beam shapes and the transition phases between them, where the laser beam shape is oriented along the cutting direction, where cutting is first along the X direction and then along the Y direction.

[0205] In any case not explicitly described, the various embodiments or their various aspects and features described with respect to the drawings may be combined or interchanged with each other without limiting or expanding the scope of the described invention, provided that such combination or interchange is meaningful and within the meaning of the present invention. The advantages described with respect to a particular embodiment of the present invention or with respect to a particular drawing are also advantages of other embodiments of the present invention, where applicable.

Claims

1. A computer-implemented method for determining a transition phase for converting different dynamic laser beam shapes by laser cutting with a laser cutting machine, the laser cutting machine including at least one optical module for dynamically changing the shape of the laser beam, the method including the following method steps: - Receive (S1) a to-be-processed cutting plan for parts for cutting out workpieces, where Each part is defined by a cutting profile including cutting segments sorted in a queue; - Providing (S2) an allocation tool (102) configured to allocate a specific dynamic laser beam shape from a set of dynamic laser beam shapes to each cutting segment in the queue of cutting segments according to predefined allocation criteria; - Iteratively accessing (S3) the allocation tool (102) to determine a specific dynamic laser beam shape for each cutting segment in the queue of cutting segments; - Providing (S4) a transition tool (104) for determining a transition phase between each two determined consecutive specific dynamic laser beam shapes, wherein, within a transition time (t), a first specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes is converted into a second specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes, wherein the transition time (t) is in the range between 0.05 ms and 10,000 ms, a hard switch from one dynamic laser beam shape to the next or consecutive dynamic laser beam shape is not applied, and the transition between different dynamic laser beam shapes is smooth and improved; - Accessing (S5) the transition tool (104) to determine all transition phases between each two determined consecutive specific dynamic laser beam shapes; - Providing control instructions (CI) for controlling the laser cutting machine (L) for executing the received cutting plan by applying: - For the specific dynamic laser beam shape of each of the cutting segments in the queue of cutting segments, the specific dynamic laser beam shape having been determined by the allocation tool (102), - For the determined transition phases between each two consecutive specific dynamic laser beam shapes of each of the cutting segments of all parts to be cut according to the received cutting plan, wherein the transition phases have been determined by the transition tool (104).

2. The method according to claim 1, wherein, The at least one optical module is a dynamic laser beam shaping module.

3. The method according to claim 1, wherein The cutting segments are selected from the group including: - Straight lines; - Circles or circular segments having a configurable specific radius; - Angles having a configurable specific angle; - Parametric curves; - Penetrations; - Introductions; - Exits and / or - Engravings.

4. The method according to any one of claims 1 to 3, wherein, The allocation tool (102) and / or the transition tool (104) includes a trained model, wherein the trained model has been trained to determine a transition phase for converting a dynamic laser beam shape between two consecutive cutting segments, and has also been trained with a training algorithm based on annotated or partially annotated training data, which includes an evaluation of the cutting results with the applied transition phase.

5. The method according to claim 4, wherein The trained model is a neural network model.

6. The method according to any one of claims 1 to 5, wherein The transition tool (104) includes an evaluation tool, wherein the evaluation tool is configured to evaluate the determined and applied specific dynamic laser beam shapes and / or transition phases manually by means of using a user interface (UI) and / or automatically by means of a sensing automatic evaluation unit (104-2) to provide an evaluation data set.

7. The method according to claim 6, wherein The evaluation data set includes a common configurable share setting different evaluation criteria, the different evaluation criteria including quality evaluation, performance evaluation, energy consumption evaluation, and / or process stability evaluation, wherein the different evaluation criteria have interdependencies, and the interdependencies are modeled on user interface selection buttons provided on a man-machine interface (UI).

8. The method according to any one of claims 1 to 7, wherein The transition phases for each two consecutive specific dynamic laser beam shapes are determined specifically for the type of material properties and / or the type of cutting machine.

9. The method according to any one of claims 1 to 8, wherein, The transition phases for each two consecutive specific dynamic laser beam shapes are determined depending on the speed and / or acceleration and / or jerk of the laser cutting head, and / or depending on the type of cutting segment, and / or depending on laser cutting process parameters, the laser cutting process parameters including laser power and / or dynamic limits of the drive.

10. The method according to any one of claims 1 to 9, wherein The transition phases for each two consecutive specific dynamic laser beam shapes are determined by generating a focal oscillation scheme by means of the spatio-temporal distribution of laser energy on the focal plane and / or the material surface, the spatio-temporal distribution being related to: - frequencies in the X and Y directions; - amplitudes in the X and Y directions; and / or - phase shifts in the Y direction compared to the X direction.

11. The method according to claim 10, wherein - the frequencies are in the X, Y, and Z directions; - the amplitudes are in the X, Y, and Z directions; and / or - the phase shifts are in the Y and Z directions compared to the X direction.

12. The method according to any one of claims 1 to 11, wherein, In the case of determining the transition phase between each two consecutive specific dynamic laser beam shapes, in which the first specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes is converted into the second specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes, a transfer function f is applied, and the transfer function f transfers the first specific dynamic laser beam shape among the two consecutive specific dynamic laser beam shapes into the second specific dynamic laser beam shape, wherein the transfer function f converts the frequency, amplitude, and / or phase shift of the first specific dynamic laser beam shape, and / or wherein the transfer function can be linear or logarithmic.

13. The method according to any one of claims 1 to 12, wherein The transition tool (104) for determining the transition phases between each two consecutive specific dynamic laser beam shapes is configured to determine the transition phases between each two consecutive specific dynamic laser beam shapes that are different from each other.

14. A control unit (100) for providing control instructions (ci) for controlling a laser cutting machine (L) by determining a transition phase for switching between different dynamic laser beam shapes for the laser cutting machine (L), the laser cutting machine comprising at least one optical module for dynamically varying the shape of the laser beam, the control unit being configured to perform the method according to any one of the preceding method claims, the control unit comprising: a cutting plan interface (101) for receiving a cutting plan to be processed for cutting out parts of a workpiece, wherein each part is defined by a cutting contour comprising cutting segments ordered in a queue; - an assignment tool (102) configured to assign a specific dynamic laser beam shape from a set of dynamic laser beam shapes to each cutting segment in the queue of cutting segments according to predefined evaluation criteria; - a transition tool (104) for determining a transition phase between each two consecutive specific dynamic laser beam shapes, wherein a first specific dynamic laser beam shape of the two consecutive specific dynamic laser beam shapes is converted into a second specific dynamic laser beam shape of the two consecutive specific dynamic laser beam shapes within a transition time (t), wherein the transition time (t) is in the range between 0.05 ms and 10.000 ms, a hard switch from one dynamic laser beam shape to an immediately following or consecutive dynamic laser beam shape is not applied, and the transition between different dynamic laser beam shapes is smooth and improved; a processor (P) configured to iteratively access the allocation tool (102) for determining a specific dynamic laser beam shape for each cutting segment in the queue of cutting segments, and wherein the processor (P) is further configured to access the transition tool (104) for determining all transition stages between each two consecutive determined specific dynamic laser beam shapes, and wherein the processor (P) is configured to provide control instructions (ci) for controlling the laser cutting machine (L) for executing the received cutting plan by applying: - the specific dynamic laser beam shape for each of the cutting segments in the queue of cutting segments, the specific dynamic laser beam shape having been determined by the dispensing tool (102), - a transition phase between each two determined consecutive specific dynamic laser beam shapes for each of the cutting segments of all parts to be cut according to the received cutting plan, wherein the transition phase has been determined by the transition tool (104).

15. The control unit according to claim 14, wherein, The at least one optical module is a dynamic laser beam shaping module.

16. A computer program comprising computer program code which, when executed by a processor (P), causes the processor (P) to perform the steps of the method of any one of claims 1 to 13.

17. A computer-readable storage medium having stored therein the computer program according to claim 16.

Images