Method for laser processing planning and / or laser processing objects with laser

Abstract

The invention relates to a method, in particular a computer-implemented method, for laser machining planning and / or laser machining of an object (1), in which a laser beam (2) of a laser can be guided by means of a galvanometer scanning system (4) along at least one predefined movement path (3) on the object (1), in which a position-dependent ideal focus curve zsoll (s) (7) is determined, a position-dependent ideal focus curve, which specifies a focus position of a laser focus (5) of the laser beam (2) in the laser propagation direction (6) along the movement path (3), is expanded by a tolerance range (11) from the position-dependent ideal focus curve zsoll (s) (7), and wherein a position-dependent adaptive focus curve (8) is determined from the position-dependent ideal focus curve zsoll (s) (7), and wherein the focus position of the laser focus (5) of the laser beam (2) in the laser propagation direction (6) is determined from the tolerance range (11). To at least comply with a dynamic limit of a focus actuator (16) for setting a focus position of the laser focus (5); the position-dependent adaptive focus curve (8) lies at least in sections within the tolerance range (11). The invention further relates to a computer program, a computer-readable storage medium and a laser processing device (19).

Description

Technical Field

[0001] This invention relates to a method for laser processing planning and / or laser processing objects, particularly a computer-implemented method, wherein a laser beam is guided along at least one preset motion trajectory on the object by means of a galvanometer scanning system, wherein a position-dependent idealized focal curve z is determined. soll (s), where the idealized focus curve associated with the position is the focal position of the laser beam's laser focus in the laser propagation direction along the motion trajectory. Background Technology

[0002] Patent document DE 10 2017 219 184 B4 discloses a laser processing method. In this method, the focal point of the processing beam is set by a focusing device.

[0003] In a 3D scanning system (i.e., a scanning system with a focusing device with a focus actuator (“z-axis”), the dynamics achievable by setting the focus along the laser beam direction are typically much smaller than the dynamic range of laser beam angular deflection and focusing in the x and y directions by two galvanometer scanners.

[0004] As is well known, in many methods, the focusing accuracy requirement is much lower than the positioning accuracy in the x and y directions, because the focal position deviation along the beam direction (“z direction”) has a negligible impact on the laser process on the order of Rayleigh length.

[0005] For the x-axis, y-axis, and focus actuator of a 3D scanning system's focusing device, regulators with tracking errors are typically used. The coordinate axes follow a preset target trajectory with tracking errors, which can lead to geometric deviations from the target trajectory—especially when the trajectory is non-linear. Modern scanning systems commonly use regulators without tracking errors, but for the z-axis, regulators with tracking errors are still generally used. Due to technical factors, regulators without tracking errors require a time curve for a preset position (trace), which can be implemented within the actuator's dynamic limits (e.g., maximum speed and maximum acceleration). Such trajectories are called "operable traces or operable motion trajectories."

[0006] If all three axes of the scanning system use non-tracking error adjusters, the operable trajectory for the z-axis must also be determined. If the 3D trajectory is calculated with acceleration or jerk limitations in mind, considering the dynamic limits of the z-axis, the overall speed is often severely limited—especially by the low acceleration limit of the z-axis, which reduces throughput in machining.

[0007] To maximize throughput in the process, in scanning systems with tracking errors along the z-axis, the 3D scanning system is typically controlled dynamically so that the focus actuator no longer fully follows the movement in all situations. For example, this can be used to locally mark pairs of shading lines that extend only slightly in the z-direction.

[0008] However, this method has the drawback of subjecting the Z-axis motor to unnecessarily heavy loads. This can cause the motor to overheat, leading to drift. Furthermore, the motor temperature may exceed its limit, triggering an emergency system shutdown. Summary of the Invention

[0009] The purpose of this invention is to reduce the motor load of a laser focusing device. Another purpose of this invention is to enable the use of a focusing device with a tracking error adjuster to simultaneously maintain or improve the usable dynamics of x-axis and y-axis positioning.

[0010] The solution of the present invention to achieve the above objectives is a method, computer program, computer-readable storage medium, and laser processing equipment having the features described in the independent claims.

[0011] This invention proposes a method, particularly a computer-implemented method, for laser processing planning and / or laser processing of an object, wherein a laser beam is guided along at least one predetermined motion trajectory on the object by means of a galvanometer scanning system. Laser processing planning can be a method step that occurs before the object is laser processed. Alternatively or concurrently, laser processing planning can also occur in parallel and / or simultaneously with laser processing. Here, future segments of the processing trajectory may have already been planned during laser processing.

[0012] In the method, the idealized focal curve z, which is related to the position, is determined. soll (s) is a preset focal position of the laser beam along the laser propagation direction, along the motion trajectory. The energy density (i.e., energy per unit area or volume) is highest at the laser focal point. In the laser propagation direction, the laser beam diverges before and after the laser focal point, and the energy density is lower than at the laser focal point.

[0013] Furthermore, the object itself and the trajectory of motion arranged on it are generally curved, so that the laser beam is incident on the object at a constantly changing angle during the guidance of the laser beam along the trajectory, and the distance of the trajectory from the galvanometer scanning system and / or the laser focusing device also changes constantly. Therefore, the laser focus must be adjusted to adapt to the trajectory so that the laser focus always processes the object along the trajectory. Preferably, the laser focus or its position should always be set so that it is located on the trajectory. Otherwise, if the laser focus is above the object and thus above the trajectory, the laser beam will diverge again before reaching the trajectory on the object, resulting in a wider area around the trajectory being processed, which can be very disadvantageous. Furthermore, due to the divergence of the laser beam, the energy density (i.e., energy per unit area or volume) may be insufficient to process the object. A similar situation occurs when the laser focus or virtual laser focus is arranged behind the object or the trajectory. Therefore, the laser beam is not focused before processing a wider area around the trajectory, and / or the energy input or energy density per unit area or volume is insufficient to process the object along the trajectory.

[0014] In the method, the idealized focal curve z, which is related to the position of the focal point of the laser beam determined along the motion trajectory in the laser processing equipment, is used to determine the focal position of the laser beam. soll (s). Idealized focus curve z, which is location-dependent. soll (s) The laser focus is preset to a position along the motion trajectory, ensuring that the laser focus remains on the trajectory at all times. Here, the position-dependent idealized focus curve z soll (s) varies with the trajectory parameter s. The trajectory parameter s can be preset, for example, as the length of the path, arc length, distance traveled, or path along the motion trajectory. For example, the trajectory parameter s can be normalized so that s is between 0 and 1. This indicates that s=0 is the starting point of the motion trajectory, and s=1 is the ending point of the motion trajectory. The trajectory parameter s can also be expressed in millimeters or centimeters. In this way, the motion trajectory is a function of the trajectory parameter s, which can be said to parameterize the motion trajectory.

[0015] Furthermore, in the method, the position-dependent idealized focus curve z soll (s) Extend the tolerance range. Here, tolerance refers to the actual focal position of the laser focus relative to the idealized focal curve z based on the position. soll (s) The distance between the ideal focal positions along the laser propagation direction.

[0016] Furthermore, in the method, based on the position-dependent idealized focus curve z soll(s) A position-dependent adaptive focus curve is determined to at least comply with the dynamic limits of the focus actuator used to set the focus position of the laser focus, and the position-dependent adaptive focus curve is at least segmentally within the tolerance range. The focus position of the laser focus is set according to the position-dependent adaptive focus curve using a focus actuator. The focus position of the laser focus is moved along the laser propagation direction using a focus actuator. Here, the focus position is moved along the laser propagation direction to realize the position-dependent adaptive focus curve along the motion trajectory. By determining the position-dependent adaptive focus curve based on the dynamic limits of the focus actuator, laser processing is planned from the outset, enabling the focus actuator to map the position-dependent adaptive focus curve and / or withstand a smaller load.

[0017] Only after such laser processing planning is completed will laser processing be performed on the previously planned motion trajectory or the previously determined position-related adaptive focus curve. This avoids overloading the focus actuator from the outset and ensures that the focus actuator can map the position-related adaptive focus curve, thereby enabling processing of the object according to a preset value or within the tolerance range of the laser focus's focal position. Here, the focus position of the laser focus can be set and / or moved along the laser processing direction using the focus actuator.

[0018] The following explains some terms. For example, the movement of the focal position of a laser focus along the laser propagation direction can be called longitudinal motion. This longitudinal motion means that the focal position of the laser focus moves along the laser beam or the laser propagation direction. This longitudinal motion is established by a focus actuator. For example, a focus actuator can be coupled to a focusing device. For example, a focus actuator can move a focusing unit (e.g., a focusing lens), thereby moving the focal position along the laser propagation direction or achieving longitudinal motion of the focal position. Conversely, the movement of the laser focus along a motion trajectory can be called trajectory motion, because the laser focus moves along a motion trajectory.

[0019] Therefore, when the position-dependent adaptive focus curve changes along the motion trajectory, the focal position of the laser focus should move longitudinally along the laser beam or along the laser propagation direction. Here, the focus actuator is controlled by the position-dependent adaptive focus curve or control data based on the position-dependent adaptive focus curve. This control can be accomplished by a computing unit and / or a control unit.

[0020] What brings an advantage is that it allows for the application of location-dependent idealized focus curves z. soll (s) Smoothing is performed to determine the location-dependent adaptive focus curve. This smoothing can also be performed piecewise only, thereby determining the location-dependent idealized focus curve z. soll(s) Segmented smoothing. This eliminates the position-dependent idealized focus curve z, especially within the smoothed segments. soll The bends present in (s) can, for example, prevent sudden changes in the orientation of the focus actuator when the focus position changes abruptly along the longitudinal direction of laser processing.

[0021] Advantageously, it allows for the determination of the idealized focus curve z, which is location-dependent. soll (s) minimizes the piecewise curvature of the position-dependent adaptive focus curve. Thus, the focus actuator only needs to apply a small acceleration.

[0022] Another advantage is that the position-dependent velocity curve of the laser focus along the motion trajectory can be determined based on the position-dependent adaptive focus curve. For example, the position-dependent velocity curve can be determined so that the focus actuator can execute the position-dependent adaptive focus curve. For instance, if the position-dependent focus curve varies too much, the focus actuator may be unable to execute these changes. In regions of excessive variation, the position-dependent velocity curve can be determined to give the focus actuator sufficient time to execute the changes in the position-dependent adaptive focus curve.

[0023] Additionally or alternatively, position-dependent velocity profiles can be determined to achieve a planned energy input along the motion trajectory. For example, if the laser focus is not precisely on the motion trajectory, a broadened laser beam is used to process the trajectory because the laser focus is located before or after the trajectory. However, this reduces the energy input per unit area of ​​the laser, which in the worst-case scenario may result in incomplete melting of the metal along the motion trajectory for welding. Position-dependent velocity profiles with relatively lower velocities in these areas can be determined, allowing the laser to remain longer in a segment of the motion trajectory, thus enabling, for example, sufficient metal to be remelted for welding.

[0024] It is useful, according to an advantageous improvement of the invention, that the position-dependent adaptive focus curve and / or position-dependent velocity curve are designed such that at least the acceleration and / or jerk of the focus actuator is limited and / or lies within the dynamic limits of the focus actuator. The limitation of the acceleration and / or jerk of the focus actuator depends on the focus actuator itself. The focus actuator has limits to the acceleration and / or jerk it is capable of performing. If these limits and / or dynamic limits of the focus actuator are taken into account when determining the position-dependent adaptive focus curve and / or position-dependent velocity curve, these limits and / or dynamic limits will always be observed.

[0025] Advantageously, position-dependent adaptive focus curves and / or position-dependent velocity curves are determined to comply with the thermal limits of the focus actuator used to set the focus position of the laser. If the focus actuator must accelerate and / or frequently set the laser focus, or if the time-averaged acceleration is too high, the focus actuator may overheat. This can be taken into account when determining the position-dependent adaptive focus curves and / or position-dependent velocity curves. When overheating occurs, a lower position-dependent velocity curve can be determined, thus giving the focus actuator more time to move the laser focus.

[0026] Another advantage is that if the position-dependent adaptive focus curve, especially if it is expected to deviate from the tolerance range, the position-dependent velocity curve is reduced in at least these regions. This gives the focus actuator more time to set the position-dependent focus curve.

[0027] A useful improvement according to the present invention is that a laser position-dependent power curve is determined along the motion trajectory, based on a position-dependent velocity curve and / or a position-dependent adaptive focus curve, to achieve a planned energy input curve along the motion trajectory. In this way, a predetermined amount of energy is introduced into the object in each segment of the motion trajectory.

[0028] For example, if too little energy is used, the metal will not melt completely during the welding process. Conversely, if too much energy is used, too much metal may melt, which will also have adverse effects.

[0029] The advantage lies in determining the position-dependent temperature profile of the focus actuator based on position-dependent adaptive focus curves and / or position-dependent velocity curves, especially through simulation prior to laser processing.

[0030] Advantageously, the motion trajectory is planned to have at least one processing segment and at least one jump segment, wherein the object is processed with a laser in the processing segment and the laser is turned off in the jump segment. At least one jump segment is adjacent to at least one processing segment, connects to the processing segment at a junction point, and / or connects at least two processing segments to each other. For example, if two processing segments are spaced apart, a jump segment can be connected. Furthermore, a jump segment can also be connected if the focus actuator cannot construct a position-dependent adaptive focus curve. For this purpose, for example, a circular trajectory can be connected in the laser beam's motion trajectory at a certain point, i.e., the junction point. This circular trajectory allows the focus actuator time to set the focus position according to the position-dependent adaptive focus curve—especially by establishing the focus change rate required for the processing segment through a pre-acceleration process. At the junction point, the laser beam decouples from the processing trajectory, passes through the circular trajectory, and then recouples back in, setting the focus position and / or focus change rate during this circular trajectory. Such junctions may be advantageous, for example, when the trajectory of motion and / or the height profile of an object has an inflection point, thus requiring a relatively rapid change in focus.

[0031] Advantageously, the motion trajectory is divided into at least two processing sections, so that in each processing section, the velocity curve related to the position of the laser focus along the corresponding processing section can be determined to be constant, thereby enabling constant processing of the object.

[0032] According to an advantageous improvement of the present invention, the motion trajectory is divided into at least two processing sections, such that in each of the at least two processing sections, the velocity curves of the laser focus along the position of the corresponding processing section are different from each other, and the velocity curves in the jump section are planned such that the velocity curves of the processing sections are connected to each other.

[0033] Advantageously, especially in at least one processing section, the tolerance range is specified as 1% to 200%, particularly 20% to 100%, of the laser Rayleigh length. The Rayleigh length refers to the distance from the laser focus, where the cross-sectional area is twice the cross-sectional area at the laser focus. The smaller the tolerance range, the more precise the positioning of the laser focus relative to the motion trajectory. Therefore, objects can be processed more accurately. However, a larger tolerance range may also be sufficient. The advantage of a larger tolerance range is that it is easier to adhere to. A larger tolerance range also allows for maintenance of the focus actuator and / or the planning of higher speed profiles.

[0034] The objective is clear: particularly in at least one processing section and / or at least one transition section, the tolerance range must be specified as being at least segmentally constant. In some areas, a larger tolerance range may be sufficient, while in others, a smaller tolerance range is required.

[0035] Alternatively or alternatively, it may be reasonable to specify the tolerance range in a location-dependent manner. For example, this tolerance range could vary with the incident angle of the laser onto the workpiece, be specified based on the local focusing characteristics of the scanning objective as a function of the xy position, or depend on the material to be processed at each location.

[0036] Depending on the laser process requirements, the tolerance range can be advantageously symmetrical about the ideal focal position, but it can also be given by different distances above or below the ideal focal position.

[0037] It may be advantageous to pre-set a tolerance range variably and / or positionally related to the motion trajectory. The tolerance range can be determined based on laser process characteristics (e.g., process thresholds for laser intensity) or calculated by means of process physics that vary with position along the motion trajectory. For example, it may be advantageous to consider the position-dependent focusing characteristics of the F-Theta optics or the oblique incidence of the laser beam on the workpiece.

[0038] An advantageous improvement according to the invention is useful in expanding the tolerance range and / or disregarding the tolerance range in the jump section. The laser may be turned off here, thus eliminating the need to consider the laser's focal position.

[0039] A potential advantage is that, in at least one transition section, the focal curve arranged therein is designed to construct a transition to the adaptive focal curve of the adjacent processing section, particularly a continuous transition and / or an operable transition. In this document, "operable" means that a preset focal curve can be controlled by a focal actuator without violating its dynamic limits, such as maximum jerk, maximum acceleration, or maximum speed.

[0040] Furthermore, it is advantageous to execute laser processing planning methods, particularly determining the position-dependent idealized focal curve z, for future segments of the motion trajectory before and / or during laser processing of the object. soll (s), position-dependent adaptive focus curves, position-dependent velocity curves, position-dependent power curves, and / or position-dependent temperature curves. This enables the optimization of laser processing planning, as the laser processing plan itself or the various curves can be planned first, and adjustments can be made as necessary.

[0041] A potential advantage is that if the tolerance range, the dynamic limits of the focus actuator, and / or the thermal limits are violated, the laser processing plan can be at least partially repeated. Here, the position-dependent adaptive focus curve, the position-dependent velocity curve, and the position-dependent power curve can be adjusted and / or modified at least segmentally. If the tolerance range, the dynamic limits of the focus actuator, and / or the thermal limits are still violated, the position-dependent adaptive focus curve, the position-dependent velocity curve, and the position-dependent power curve can be adjusted and / or modified at least segmentally again. Here, the above curves can be repeatedly adjusted until the tolerance range or the stated limits are met.

[0042] An improvement could be achieved by using a smoothing filter (especially an FIR filter, preferably a moving average filter or a binomial filter) for smoothing.

[0043] Advantageously, the method for laser processing planning and / or laser processing of objects is executed by the computing unit. The computing unit may also be a control unit of the laser processing equipment. Alternatively or additionally, the computing unit may also include a control unit. Alternatively or additionally, the control unit may also include a computing unit.

[0044] In addition, the present invention also proposes a computer program that, when executed by a computing unit, performs the method according to one or more features above and / or below.

[0045] Furthermore, the present invention also proposes a computer-readable storage medium containing a computer program, wherein when the computer program is executed by a computing unit, it causes the computing unit to perform the method according to one or more features above and / or below.

[0046] Furthermore, the present invention also proposes a laser processing apparatus for laser processing planning and / or laser processing objects.

[0047] The laser processing equipment includes a laser for processing the object. The laser can be used to weld, cut, and / or mark objects, for example. The laser processing equipment may include a laser source for generating the laser. Alternatively or additionally, laser light from an external laser source may be coupled into the laser processing equipment.

[0048] The laser processing equipment further includes a galvanometer scanning system for guiding the laser beam from the laser onto the object, wherein the galvanometer scanning system includes a focus actuator for setting the focus position of the laser beam. The galvanometer scanning system may, for example, include a focusing device that includes the focus actuator. For example, the focus actuator can move the focusing unit of the focusing device, thereby moving the focus position along the laser propagation direction.

[0049] In addition, the laser processing equipment also includes a computing unit. The computing unit may also be a control unit of the laser processing equipment. Alternatively or additionally, the computing unit of the laser processing equipment may also include the control unit of the laser processing equipment. Alternatively or additionally, the control unit of the laser processing equipment may also include the computing unit of the laser processing equipment.

[0050] The computing unit is configured to perform the method according to one or more method steps described above and / or below.

[0051] The laser processing planning and / or laser processing can also be carried out, for example, as follows.

[0052] 1.) The processing task is divided into a processing section (“Mark”) and a jump section (“Jump”).

[0053] 2.) The trajectory [x(s(t)),y(s(t))] is planned according to the conventional two-dimensional method in order to comply with the dynamic limit of the x / y oscillator.

[0054] At this point, the time curve s(t) of the trajectory process can be temporarily defined. Typically, the marking speed in the processing section is planned to be basically constant, while the jump speed in the jump section is planned to be optimized over time.

[0055] 3.) In the processing section, z_soll(s) is calculated based on the functional relationship z_soll(s)=z(x(s), y(s))—especially for establishing flat field correction.

[0056] 4.) In the processing section, a tolerance band [z_min...z_max] is specified for the preset z-coordinate geometric curve z_soll(s), and its width varies with the acceptable local defocus.

[0057] In the jump section, the maximum range of values ​​that the focus actuator can control is defined as the tolerance band.

[0058] 5.) Define a smooth curve z(s) whose trajectory lies entirely within the tolerance zone and has minimum curvature d along its path. 2 / ds 2 (z). This step is independent of step 2 in terms of sequence, because steps 3, 4 and 5 can be performed without depending on the time curve of z.

[0059] 6.) Check whether z(s(t)) complies with the dynamic limits of the z-axis actuator (especially velocity and acceleration).

[0060] Otherwise, reduce / limit the speed and repeat the planning from step 2. It may be advantageous here to specify different speed limits for the marker speed and the jump speed, or to set speed limits only locally. This can be determined by analyzing the limit violations of z(s(t)).

[0061] 7.) Optionally, it is possible to additionally check whether the thermal limit of the z-axis driver is exceeded due to the driver and further reduce the speed.

[0062] 8.) Optionally, the deviation between the z-coordinate and the ideal trajectory δz = |z(s(-) - z_soll(s)(s(t))| can be compensated by controlling the laser, where other compensations such as velocity deviation can also be taken into account.

[0063] A more general planning approach may also include the following steps and features: 1. Compensating for defocus by controlling another degree of freedom—especially by adjusting laser power based on a characteristic curve that reflects the relationship between the effect of laser radiation in the laser process and defocus. This may also include: a. The influence of trajectory velocity; b. The effect of oblique incidence caused by x / y deflection.

[0064] 2. Based on the following characteristics, an optimization method is used to plan the trajectory: For the planned active laser section (processing section), for each point along the 3D target trajectory p_soll(s)=(x_soll(s), y_soll(s), z_soll(s)), based on the laser beam characteristics (especially the Rayleigh length) and laser process characteristics (especially the laser defocus tolerance), the tolerance band [z_min(s) ... z_max(s)] is defined with respect to the z-coordinate curve z_soll(s) of the target trajectory.

[0065] In the processing section, the trajectory p(s) is planned using the following boundary conditions and optimization objective ae: a. It has a small geometric deviation relative to the target trajectory in the x and y directions, |x_soll(s) - x(s)| or |y_soll(s) - y(s)|.

[0066] The bz coordinates are within the tolerance band: z_min(s) <= z(s) <= z_max(s), where optionally, the deviation relative to the center |z(-) - z_soll(s)| can be kept small.

[0067] The temperature rise of the Cz axis driver is not high (modeled using current integration and cooling mechanisms to minimize the acceleration used, which may depend on the modeling temperature).

[0068] d. The deviation between the velocity v = d / dt(p(s(t)) and the target trajectory velocity v_soll is small, or the trajectory velocity is maximized segment by segment.

[0069] e. Does not violate the dynamic limits of the x-axis, y-axis, and z-axis (the dynamic limits are usually the maximum absolute values ​​of the first, second, and third time derivatives of the p(s(t)) component).

[0070] Optimization can be performed on optimization objectives that include specific weights for the aforementioned criteria (ae). These weights can also be influenced by user settings, such as the marker command parameters in a machine-readable machining task description.

[0071] In this situation, it may not be possible to optimize the entire trajectory length in a reasonable way. Instead, the trajectory should be divided into at least two sub-segments, and then these two sub-segments should be connected through a laser deactivation transition phase.

[0072] Optimization algorithms can automatically perform such partitioning based on appropriate criteria.

[0073] During the laser deactivation phase (the "Jump" or transition section of the processing task), the trajectory followed by the laser focus is irrelevant. At this time, in order to shorten the optimized execution time, the boundary conditions at the start and end points of the section must be observed. These boundary conditions are preset by the endpoints of the adjacent "Mark" phase or processing section (active laser phase).

[0074] The dynamic limits of the x-axis, y-axis, and z-axis drives will be considered here. The tolerance zone of the z-axis motion can also be used as an optimization free space for transition points between "Jump" and "Mark" segments or between jump and machining segments. In particular, the optimization algorithm can perform overall optimization for multiple associated "Jump" and "Mark" segments or jump and machining segments, i.e., planning non-zero z-bias at the start or end of at least one "Mark" segment.

[0075] This method can also be interactive with the user. The software can display the planning results and highlight key points that violate the limits. The user can then be prompted to choose an algorithm from a list to overcome the limit violation. For example, the user can modify parameters to relax the set limits, or alternatively, the software can use "Jump" stages or jump sections to overcome the limit violation.

[0076] If the so-called 2.5D laser process is applied, in order to comply with the laser process specifications while minimizing the user's workload, the z-component is of relatively low importance. For example, the z-component only originates from flat field correction or surface curvature correction of the workpiece to be processed.

[0077] A possible alternative planning approach can also be described through the following steps: Step 1: Starting from the preset target trajectory curve p=(x(s), y(s), z(s)) (which is also the position-dependent idealized focal trajectory), firstly, plan the trajectory p_xy(s(t)) = (x(s(t)), y(s(t)) only for the x and y components of the motion, i.e., the time curve of the trajectory parameter s(t). In this step, the dynamic limit of the scanning system galvanometer is considered. The trajectory velocity |d / dt(p(s(t))| is kept basically constant along the trajectory at the preset target trajectory velocity value. Smoothing is performed at corners, not exceeding the preset maximum geometric corner deviation, in order to comply with the dynamic limit of the galvanometer driver. If smoothing is insufficient to comply with the limit, the trajectory is automatically divided into two segments and connected by a swinging motion in the laser-off state ("Skywriting").

[0078] Step 2: Based on the results of the planning, determine the target time curve of the z-coordinate z_soll(s(t)) based on the determined trajectory process s(t).

[0079] Step 3: By performing digital filtering on z_soll(s(t)), the smoothed time curve of z(s(t)) can be determined, and its acceleration |d 2 / dt 2 (z(s(t)))| does not exceed the preset maximum acceleration a_z_max of the focus actuator. Here, the filter parameters can be predetermined to ensure reliable compliance with the acceleration limit, or the filter parameters can be iteratively adjusted until the condition is met.

[0080] Step 4: For the obtained curve z(s(t)) (i.e., the position-dependent adaptive focus curve), determine whether it is within the tolerance limit everywhere: z_min(s) <= z(s) <= z_max(s). If yes, the planning result has been achieved. If not, reduce the preset target velocity (at least in the relevant segments of the trajectory) and repeat the entire method with the new, lower preset target velocity.

[0081] Therefore, if the machining task is subdivided into multiple segments with different speeds, it is advantageous to connect these segments through a transition phase while the laser is off, so as to set a modified target speed. Alternatively, the transition of trajectory speed over time can be transitioned to another trajectory speed.

[0082] As a variation or alternative to the above method, the following approach is also feasible and may be particularly advantageous for implementing an efficient algorithm. This approach is particularly suitable for cases where z-axis motion is corrected for a focus derived from x and y values.

[0083] Step 1a: Perform trajectory planning for the x and y components using conventional methods. This determines the operable time curves x(s(t)) and y(s(t)) for the x-axis and y-axis actuators. In particular, a substantially constant trajectory speed can be planned.

[0084] Step 1b: Calculate the pure geometric curve of z(s) to maximize the use of the tolerance band z_min(s) <= z(s) <= z_max(s), thereby achieving a geometrically smooth preset curve. As a criterion, minimize the derivatives dz / ds and d... 2 z / ds 3 The maximum value of etc. That is, first determine the geometric trajectory z(s) with respect to the z component that is smoothed to the maximum extent (this step can be done largely independently of step 1a, provided that the preset trajectory geometry is not modified in step 1a).

[0085] Step 2: Then, based on the time curve of the trajectory parameter s(t) determined in the xy trajectory planning, it can be checked whether the dynamic limit of the z-actuator along the (geometrically smoothed) trajectory z(s(t)) is also observed at the preset trajectory speed. If not, the speed is reduced in a similar manner to the above, and the planning is repeated with the new speed value. At this time, as in the above method, the processing task can also be subdivided into multiple segments.

[0086] This method may benefit from the fact that, in numerical computation, the smoothed trajectory does not need to be recalculated when the trajectory speed is modified. Therefore, in this variant, finding an optimal marking speed is more numerically efficient. The method's advantage may also be attributed to the fact that the z-axis actuator experiences minimal load at the preset marking speed, thus operating in a (near) optimal thermodynamic state. However, the method's drawback is that, due to the need to fully utilize the tolerance band, the z-coordinate deviation may be unnecessarily large. In practice, this drawback can be mitigated because the user can preset the tolerance band to be even narrower.

[0087] For example, trajectory planning can be performed according to the following method, where the time curve of the trajectory progress is pre-determined based on the planning for x(t) and y(t). This method includes the following steps: 1. First, based on the dynamic limits of the corresponding actuators, the x and y components are planned. This initially defines the trajectory progression s(t): x(s(t)), y(s(t)). In this step, a basically constant marker velocity can be specified, while adhering to the dynamic limits of the x and y axes.

[0088] 2. Then, a tolerance band is defined with respect to the z coordinate, where, through the determined time parameterization, the limits z_min(s(t)) and z_max(s(t)) of the tolerance band are defined for each moment t.

[0089] 3. The z - trace planning is carried out by an optimization algorithm, which defines a curve of the z coordinate along the time axis within the tolerance range. Here, the dynamic limits of the z - axis can be described, for example, by the maximum absolute values of the velocity and acceleration in the z - direction: |dz / dt| < v_zmax and |d 2 z / dt 2 | < a_zmax.

[0090] A very simple but numerically inefficient method is the iterative optimization of the filter parameters. The target curve of the z coordinate is filtered to reliably comply with the dynamic limits. Search methods can be used to determine the filter parameters to further limit the dynamic characteristics of the z - axis without violating the tolerance range.

[0091] The goal may be to keep the actuator heating calculated based on the model below a temperature threshold. Here, the filter parameters can also be selected differently in segments. As a filter, a smoothing filter can be used, such as a FIR filter, especially a moving - average filter or a binomial filter.

[0092] 4. If such a z - trace cannot be determined for the entire trajectory, the trajectory is divided into multiple segments, which are connected by transition trajectories (jump segments, so - called "Skywriting"). Alternatively, the preset dynamic limits of the x - axis and y - axis of at least part of the trajectory or the entire trajectory can be reduced, and the method described above is reapplied to these segments.

[0093] This may, for example, be equivalent to reducing the constant marking speed selected for the x - motion and y - motion.

[0094] The optimization task of complying with the tolerance range is similar to the so - called "Racing Car" optimization task, for which many documents have proposed appropriate methods.

[0095] The trajectory optimization with the goal of minimizing the actuator heating is similar to the robot trajectory planning task with the goal of optimizing the energy consumption.

[0096] As shown in the figure above, when planning the motion, the limitation of the actuator heating can be taken as the optimization goal. Heat is introduced through electrical energy, mainly due to the ohmic losses in the actuator coil. Other mechanisms include frictional losses caused by internal and external frictional effects and induction heating caused by eddy currents and thin - film magnetization. Through these mechanisms, a part of the energy input into the system components is deposited as heat in the actuator.

[0097] The behavior of a system can be approximated using models. For example, the energy input after ohmic heating can be calculated by integrating the input current over time. The acceleration of an electromagnetic actuator is approximately proportional to the current intensity.

[0098] Overcoming the temperature rise utilizes cooling mechanisms, which can be modeled using thermal resistance and the temperature difference with the heat storage device. The model can also use multiple temperatures of system components and the thermal resistance between these components.

[0099] Based on this model, the temperature profiles of each actuator in the system can be predicted from the 3D traces (time curves of position). The prediction accuracy can be improved by adjusting the model parameters based on experimental measurements.

[0100] It is also possible to model, in particular, the actuators on the system's focal axis (z-axis). This is especially important because these system components have low dynamic potential within the overall system and therefore must operate closer to their thermal design limits.

[0101] In trajectory planning methods, temperature can be modeled to form limiting conditions or optimization criteria. For example, the temperature rise can be limited to below the maximum temperature, or the temperature function can be incorporated into the evaluation index describing the optimality of the solution.

[0102] Here, the expected optimization goal could also be to ensure heat input in stages so that the temperature of the driver does not fall below the target operating temperature, for example, to avoid temperature drift, thereby improving the accuracy of the entire system.

[0103] Trajectory planning in a 3D system can be performed automatically based on input data that describes the following information: • Target geometry (e.g., 3D trajectory shape) • Dynamic limits of actuator and laser settings • Process boundary conditions (e.g., speed window) • Optimize preset values ​​(e.g., criterion weights) These input data may vary depending on the task, but a task may also consist of multiple different segments that require different input data (different parameters and / or different parameter values).

[0104] Therefore, if the user interface is designed to allow users to describe machining tasks as a set of subtasks or a series of multiple subtasks, each with its own suitable set of parameters, the program interface can provide commands or macros that describe not only basic geometric elements (such as a single directed line) but also larger composite objects (such as the filling of a bounded region). Here, parameters can describe which target parameters in a segment are relevant to optimization. For example, for contours, trajectory fidelity may be more important than for fillings.

[0105] The user interface can also provide the function of automatically subdividing the machining task into appropriate segments based on machining parameter analysis. One reasonable criterion is the characteristic factor describing the temperature rise of the z-axis drive. For example, the acceleration in the z-direction can be analyzed by calculating the time average within a time window.

[0106] Then, optimization can be performed in segments as appropriate, with each segment applying its own applicable criteria. As mentioned in other paragraphs, not all goals (all limits) can always be achieved. In such cases, while automatic adjustment / correction can be achieved through rules built into the algorithm, in practice, the overhead of precisely configuring such software to handle all possible anomalies is enormous.

[0107] Therefore, a user interface should be clearly provided to show users the intermediate results of the planning process and highlight the deviations from preset values ​​or the degree to which optimization criteria are met. This can be achieved, for example, through a graphical user interface that displays the trajectory and, for example, uses color codes to highlight problematic trajectory points. Action suggestions can be provided to users, explaining how to adjust the planning preset values ​​to achieve better results.

[0108] In particular, it could be suggested that intermediate sequences be connected at a certain point, or that the trajectory speed be reduced in a certain segment, to allow more time for processing planning to reduce the deviation between the z-coordinate and the target trajectory. Alternatively, it could be suggested that deviation be exceptionally tolerated at a certain point.

[0109] Therefore, the user interface can also display time curves of control parameters or system parameters.

[0110] To this end, the user interface can also display characteristic factors that can be formed for the entire processing task or its various sections, such as execution time, current consumption, average power, laser utilization, etc.

[0111] Such a user interface allows users to optimize control trajectories interactively, manually, or semi-automatically—especially by manually changing preset parameters and analyzing simulation results.

[0112] The user interface also allows users to store or adjust information about process relationships, such as the relationship between laser defocusing and the laser power required in the process.

[0113] The user interface can provide a means to reorder the segments of the processing task, thereby separating the high heat input segments from the low heat input segments in time to prevent excessive heat buildup in the driver and thus allow it to cool down below the critical temperature.

[0114] The user interface can provide means to properly design the cooling of the scanner device. For example, it can provide simulation results of driver temperature rise at different coolant temperatures or different speeds, so as to select the appropriate temperature (coolant, driver operating point temperature) or specify the scanner speed.

[0115] The user interface can be graphical or a programming library, or it can be formed through input / output files.

[0116] The intensity curve of a high-quality laser beam within its focal region can be mathematically described using the concept of a Gaussian beam. Similar or extended representations are commonly used for other beam shapes or lower beam qualities. The beam diameter of a laser beam reaches a minimum in the focal region and varies very little over a characteristic length (Rayleigh length) along the beam propagation direction. For example, the beam diameter can be linearly proportional to the distance from the focal point, for instance, as the distance along the beam direction increases.

[0117] If the laser beam is not incident on the workpiece, the beam diameter and / or intensity distribution on the workpiece can be calculated based on the mathematical model of the laser beam and the distance (defocus)—the intensity typically decreases when the beam is defocused. Based on this calculation, along with a process model or appropriate characteristic curves, the laser power can be determined so that the laser process results are closer to those achievable with a focused laser (or other desired specific non-zero focusing distance).

[0118] This calculation can also incorporate other values ​​that depend on the current trajectory coordinates or velocity. For example, position-dependent compensation can be made for oblique incidence on the workpiece, or the optical characteristics of the F-Theta lens of the optical scanning system can be taken into account.

[0119] Conversely, for example, due to misalignment of the focusing system's moving axis, parasitic offsets may also occur in the x and y directions when defocusing occurs in the z direction. If this has not been compensated for in the coordinate transformation of the control system through subsequent processing, the accuracy can be improved by adjusting the x and y coordinates of the control values ​​accordingly when planning defocusing. Attached Figure Description

[0120] Further advantages of the present invention will be described below with reference to embodiments. In the figures: Figure 1 Two schematic implementation schemes of the laser processing equipment are shown; Figure 2 A schematic diagram showing different focal positions of the laser is provided. Figure 3 A schematic example of a motion trajectory is shown; Figure 4 Several different curves are shown in the graph; Figure 5 Several different curves are shown in the graph; Figure 6 Two schematic motion trajectories on the object are shown; and Figure 7 A graph showing the focus curve and its tolerance range is presented. Detailed Implementation

[0121] Figure 1 Two embodiments of the laser processing apparatus 19 are shown. The only difference between the two embodiments is that, in the embodiment on the right, the laser processing apparatus 19 includes a telecentric flat-field optics element 18, which is described in detail below. Apart from this, other descriptions of the laser processing apparatus 19 and its features apply to both embodiments.

[0122] Using the laser processing equipment 19 shown, the object 1 can be processed by means of the laser beam 2 of the laser. For example, the processing may involve welding, cutting and / or marking the object 1 and / or locally melting the powder for 3D printing using the LPBF method.

[0123] The laser beam 2 is guided along motion trajectory 3 to process object 1. In this figure, motion trajectory 3 is shown as a straight line, for example. Generally, motion trajectory 3 can also be curved. Object 1 is welded, cut, and / or marked along motion trajectory 3, for example.

[0124] The laser processing equipment 19 includes a galvanometer scanning system 4 to guide the laser beam 2 along a motion trajectory 3 and / or across an object 1. The galvanometer scanning system 4 can deflect and move the laser beam 2. For this purpose, the galvanometer scanning system 4 may include a first deflector 20 and / or a second deflector 21. The first deflector 20 and / or the second deflector 21 can be moved to deflect and move the laser beam 2. Here, the two deflectors 20 and 21 shown in this figure have advantages. The first deflector 20 can deflect the laser beam 2 in a first direction, while the second deflector 21 can deflect the laser beam in a second direction. With the first deflector 20 and / or the second deflector 21, the laser beam 2 can be adjusted in the x and y directions shown in this figure. Therefore, the laser beam 2 can be guided across the object 1 according to the x and y coordinates of the motion trajectory 3.

[0125] Here, the first deflecting mirror 20 and / or the second deflecting mirror 21 may include associated actuators for moving the first deflecting mirror 20 and / or the second deflecting mirror 21.

[0126] Furthermore, the galvanometer scanning system 4 includes a focus actuator 16, by which the focus position of the laser focus 5 of the laser beam 2 along the laser propagation direction 6 can be set. The focus actuator 16 allows the laser focus 5 to be shifted or moved along the laser propagation direction 6. It is advantageous for the laser-processed object 1 to have the laser focus 5 located on and moving along the motion trajectory 3. If the laser focus 5 is located above or below the motion trajectory 3 and / or the object 1, the laser processing quality may decrease. Here, "above" and "below" are relative to the laser propagation direction 6.

[0127] According to this embodiment, the galvanometer scanning system 4 includes a focusing device 22, which includes a focus actuator 16. The focusing device 22 also includes a focusing unit 23 that is moved and / or controlled by the focus actuator 16. By moving the focusing unit 23, the laser focus 5 can be moved along the laser propagation direction 6. As shown in this figure, the focusing unit 23 can be, for example, a diverging lens and / or include a diverging lens. However, the focusing unit 23 can also be implemented, for example, by a movable converging lens, especially in a collimating device.

[0128] Furthermore, the focusing device 22 may include at least one lens 24 as shown in this figure. With the aid of at least one lens 24 as shown in this figure, the laser beam 2 can be focused to form a laser focal point 5.

[0129] In addition, according to Figure 1 In the embodiment on the right, the laser processing equipment 19 and / or the galvanometer scanning system 4 include a telecentric planar optics 18. This telecentric planar optics 18 allows the laser beam 2 to be vertically guided onto the object 1. Figure 1 In the embodiment on the left, there is no telecentric flat-field optics 18. Therefore, the laser beam 2 is guided obliquely onto the object 1. This would also occur, for example, if no flat-field optics are used in a non-telecentric arrangement.

[0130] Additionally, this figure also shows a computing unit 17, by which laser processing planning and / or laser processing of object 1 can be executed and / or controlled. Here, the laser processing equipment 19 may include the computing unit 17. The computing unit 17 may also include a control unit for controlling the laser processing. Alternatively, the computing unit 17 may be arranged in the control unit of the laser processing equipment 19. Laser processing planning and laser processing may also be executed by two separate computing units 17. For example, the computing unit 17 may be part of a personal computer (PC), by which laser processing planning and / or laser processing and / or control of laser processing planning and / or laser processing can be executed.

[0131] For the sake of brevity, features already described in at least one of the preceding figures will not be repeated. Furthermore, only features in this figure or at least one of the following figures will be described. Additionally, for the sake of brevity, identical features are labeled with the same reference numerals. Furthermore, for clarity, not all features are shown and / or labeled with reference numerals in the figures. However, features shown in one or more preceding figures may also appear in one or more following figures. Additionally, for clarity, features may only be shown and / or labeled with reference numerals in this figure or one or more following figures. However, features shown in one or more following figures may also already exist in this figure or preceding figures.

[0132] Figure 2 Three schematic diagrams are shown showing different focal positions of laser focus 5.

[0133] This figure shows object 1 and laser beam 2. It also shows the laser propagation direction 6 and laser focus 5. Laser focus 5 is characterized by the smallest cross-section of laser beam 2 at this location. Along the laser propagation direction 6, laser beam 2 has a larger cross-section in the region before and after laser focus 5. Generally, it is most advantageous for laser processing that laser focus 5 is located precisely on the object surface 26 of object 1 and / or on the motion trajectory 3. Generally, motion trajectory 3 is located within or above object surface 26. The middle figure illustrates this relationship between laser focus 5 and object surface 26 and / or motion trajectory 3. In this figure, the distance 25 between laser focus 5 and object surface 26 and / or motion trajectory 3 is zero.

[0134] In contrast, in the left figure, the laser focus 5 is positioned in front of the object surface 26 and / or the motion trajectory 3 along the laser propagation direction 6. Therefore, the distance 25 in the left figure constitutes the distance between the laser focus 5 and the object surface 26 and / or the motion trajectory 3.

[0135] In the right figure, the laser focus 5 is positioned behind the object surface 26 and / or the motion trajectory 3 along the laser propagation direction 6. Therefore, the distance 25 between the laser focus 5 and the object surface 26 and / or the motion trajectory 3 is also defined.

[0136] The following Figures 3 to 5 The view illustrates a simple trajectory planning task and the time curves of feasible solutions. In this example, a trajectory containing two serpentine patterns should be processed. This example assumes that the focusing device 22 of the scanning system should compensate for the image field curvature of the front-focusing scanning system without a flat lens. Here, a preset trajectory for the z-axis control coordinates is calculated using a formula based on the x and y values; this is a typical scenario.

[0137] Processing can be performed using laser power in the range of, for example, approximately 20 watts.

[0138] Figure 3An example of motion trajectory 3 is shown in the figure. Motion trajectory 3 is two-dimensional in this figure, that is, it has x-coordinates and y-coordinates.

[0139] The motion trajectory 3 has a trajectory start point 27 and a trajectory end point 28, wherein the laser beam 2 moves along the motion trajectory 3 from the trajectory start point 27 to the trajectory end point 28.

[0140] The motion trajectory 3 has at least one processing segment 9 and / or at least one jump segment 10. In at least one processing segment 9, the object 1 is processed, for example, welded, cut, or marked. In at least one jump segment 10, the laser is turned off, so no processing occurs. The jump segment 10 shown in this figure is located at the trajectory endpoint 28. In this example, the jump segment 10 shown in this figure is used to guide the turned-off and so-called virtual laser beam 2 to the trajectory start point 27 of another motion trajectory 3, or to guide the turned-off or so-called virtual laser beam 2 back to the waiting position.

[0141] According to this embodiment, the processing section 9 shown in this figure includes a first serpentine section 14 and a second serpentine section 15. An intermediate section 32 is arranged between these two serpentine sections 14 and 15. In this intermediate section 32, the motion trajectory 3 or the processing trajectory 9 is a straight line.

[0142] Figure 4 and Figure 5 The adaptive focus curve 8, related to the planned z-coordinate position, is shown within the tolerance band (dotted line) around the target curve (dashed line). The z-coordinate represents the focal position of the laser focus 5 along the laser propagation direction 6. The curve is smooth and follows fluctuations in the z-direction only to a very limited extent. When the laser is controlled, both focus deviation and deviation from the preset trajectory velocity must be considered.

[0143] Figure 5 The image shows a magnified detail illustrating the deviation from the tolerance band center based on the z-coordinate and the laser power correction based on the trajectory velocity. If the velocity at the trajectory inflection point decreases, the laser power increases. Similarly, a larger deviation from the tolerance band center also results in a higher laser power.

[0144] Figure 4 and Figure 5 The bottom figure shows the predicted temperature curve driven by the z-axis, which is calculated using a simple model based on the acceleration curve of the adaptive focus curve.

[0145] exist Figure 4 and Figure 5In the diagram, to represent time dependence, the monotonic relationship s(t) is mathematically inverted to t(s) so that position-dependent parameters can be represented as time-dependent parameters. Since s(t) is invertible, this representation is equivalent. This is equivalent to the form of a typical output control program of the computing unit when controlling the actuator.

[0146] Figure 4 and Figure 5 This is shown in the middle. Figure 3 The motion trajectory 3 shown is matched by multiple curves 7, 8, 12, 29, 30, and 31. Figure 5 The figure shows the position-dependent velocity curve 12 and the position-dependent idealized focus curve z. soll (s)7, position-dependent adaptive focus curves; 8, position-dependent power curves; 13, and position-dependent temperature curves. Figure 4 In addition to Figure 5 In addition to curves 12, 7, 8, 13, and 31, position-related x-coordinate curve 29 and y-coordinate curve 30 are also shown.

[0147] Figure 5 The same curves 12, 7, 8, 13, and 31 are shown, but in a magnified detail. Figure 5 The local area shown includes a small first serpentine segment 14, a middle segment 32, and a large second serpentine segment 15.

[0148] Figure 4 The two figures above show the x-coordinate curve 29 and y-coordinate curve 30 of the motion trajectory 3, respectively.

[0149] Two serpentine segments, 14 and 15, can be clearly seen in the x-coordinate curve 29 and the y-coordinate curve 30.

[0150] Figure 4 The fourth figure from the top shows the idealized focal curve 7, and Figure 5 The idealized focal curve 7 is also shown in the second figure from the top. The idealized focal curve 7 represents the focal position of the laser focus 5 along the motion trajectory 3 in the laser propagation direction 6. Figure 5 The idealized focal curve 7 (shown as a dashed line) is seen more clearly in the middle.

[0151] Here, the idealized focal curve 7 represents the optimized focal position of the laser focal point 5 along the laser propagation direction 6. According to... Figure 5The idealized focus curve 7, especially within the region of the second serpentine segment 15, is also serrated (e.g., similar to the y-coordinate trajectory 30). This could be attributed, for example, to the object 1 being curved at least within the region of the second serpentine segment 15, or to the laser beam 2 being incident on the object 1 at alternating gentler and steeper angles according to the serpentine shape. For example, if the angle at which the laser beam 2 is incident on the object 1 becomes steeper, the laser focus 5 shifts above the object or above the object surface 26. The laser focus 5 no longer reaches the motion trajectory 3 on the object 1 or object surface 26. Therefore, the focus actuator 16 must move the laser focus 5 along the laser propagation axis 6 and further toward the object 1. If the angle at which the laser beam 2 is incident on the object 1 becomes smaller again, the laser focus 5 will move into the object 1, such as... Figure 2 As shown in the right figure. The focus actuator 16 is required to move the laser focus 5 again along the laser propagation axis 6 and move it away from the object 1. The focus actuator 16 positions the laser focus 5, for example, relative to the object 1, the motion trajectory 3, and / or the object surface 26. The focus actuator 16 sets the focus position of the laser focus 5 relative to the object 1, the motion trajectory 3, and / or the object surface 26.

[0152] However, the focus actuator 16 cannot arbitrarily and quickly set the focus position of the laser focus 5. For example, due to inertia, the focus actuator 16 cannot perfectly match the idealized focus curve z. soll (s)7 is used to map the focal position of laser focus 5. Focus actuator 16 has a dynamic limit, which hinders the achievement of a (non-constant) idealized focus curve z. soll (s)7. Of course, this only applies to the idealized focal curve z. soll (s)7 Non-constant cases.

[0153] In laser processing planning methods, the position-dependent idealized focal curve z soll (s)7 extends the tolerance range to 11.

[0154] Subsequently, based on the idealized focus curve z soll (s)7 determines the adaptive focus curve 8 to at least comply with the dynamic limits of the focus actuator 16 used to set the focus position of the laser focus 5, and the adaptive focus curve 8 is at least segmented within the tolerance range 11.

[0155] Figure 5 The adaptive focus curve 8 is clearly shown in the diagram. For example, the idealized focus curve z is shown in the adaptive focus curve 8. sollPeak smoothing in (s)7. This prevents the focus actuator 16 from having to suddenly change the focus position of the laser focus 5. Adapting the focus curve 8 makes the movement of the focus actuator 16 smoother, thus preventing overload of the focus actuator 16. When determining the adapted focus curve 8, the tolerance range 11 is taken into consideration. Here, the tolerance range 11 can be selected based on the required precision of the laser processing and / or the characteristics of the laser beam.

[0156] also, Figure 4 and Figure 5 The diagram also shows a velocity curve 12, which can be determined based on the position-dependent adaptive focus curve 8. Velocity curve 12 presets the velocity of the laser focus 5 along the motion trajectory 3. (As shown...) Figure 4 and Figure 5 As shown, the velocity curve has 12 decreasing regions, which are arranged around the idealized focal curve z. soll At the inflection point of (s)7. Thus, at the idealized focus curve z soll At the inflection point of (s)7, the speed of the laser focus 5 is reduced, so that the focus actuator 16 can set the focus position of the laser focus 5.

[0157] Figure 4 and Figure 5 The diagram also shows a power curve 13, which can be determined based on the adaptive focal curve 8 and / or the velocity curve 12. Power curve 13 presets the power of the laser along the motion trajectory 3. Figure 4 and Figure 5 As shown, power curve 13 has 13 decreasing and / or increasing regions. This can, for example, compensate for the decreased velocity in velocity curve 12. When the velocity of laser focus 5 decreases, if the laser power remains constant, more energy will be introduced into the trajectory segment. Power curve 13 can be determined to achieve uniform energy input along the machining trajectory 9.

[0158] also, Figure 4 and Figure 5 The diagram also shows temperature curve 31, which represents the temperature of the focal actuator 16 along motion trajectory 3. This temperature curve can provide information about whether the focal actuator 16 is overheating or overheating. If the limit temperature is exceeded, especially in the section exceeding the limit temperature, the speed curve 12 can be lowered, for example.

[0159] Figure 4 and Figure 5The curves 7, 8, 12, 13, 29, 30, and 31 depicted are preferably planned before laser processing of object 1. Laser processing planning and laser processing can also be performed in parallel, wherein the motion trajectory is planned and processed segment by segment. In this way, future segments of motion trajectory 3 can be planned during the processing of a segment of the currently planned motion trajectory 3.

[0160] Figure 6 Two exemplary motion paths 3a and 3b are shown on curved objects 1a and 1b. The letters "ABC" should be engraved on objects 1a and 1b, which can also be done using laser processing. The two letter combinations have the same trajectory start point 27 and the same trajectory end point 28.

[0161] Furthermore, these two letter combinations share the same processing sections 9a, 9b, and 9c. The first processing section 9a forms "A", the second processing section 9b forms "B", and the third processing section 9c forms "C".

[0162] The difference between the two motion trajectories 3a and 3b lies in the jump segments 10a-10f.

[0163] In motion trajectories 3a and 3b, the direction of movement of laser beam 2 is indicated by arrows.

[0164] In the upper motion trajectory 3a of the object 1a, starting from "A". Here, the first diagonal line of "A" is processed first, then the second diagonal line of "A" is processed, followed by the first jump segment 10a. During the first jump segment 10a, the laser is turned off. During the first jump segment 10a, the galvanometer scanning system 4 is controlled to correctly position the laser beam 2 to process the horizontal bar of "A". After completing "A", the second jump segment 10b continues, then "B" is processed, followed by the third jump segment 10c, thereby positioning the laser beam 2 on the object 1a to process "C".

[0165] The object 1a below also follows the motion trajectory 3b. In addition to the jump segments 10a-10c of the first or upper motion trajectory 3a, three more jump segments 10d-10f are added.

[0166] These three jump segments 10d-10f connect to their respective connection points 33a-33c. These three jump segments 10d-10f couple out and recouple at their respective connection points 33a-33c. These three jump segments 10d-10f are used to compensate for sudden changes in direction, such as at the tip of “A”. At these points, the focus actuator 16 would otherwise have to abruptly reverse the movement of the laser focus 5 because the object 1b is curved; the laser focus 5 must first move towards the object 1b, and then move away from the object 1b after the tip of “A”. This sudden reversal of direction places a high load on the focus actuator 16, making it impossible for it to perform. By using the jump segments 10d-10f at such points on the object 1, time can be gained for the focus actuator 16 to set the focus position of the laser focus 5 and accelerate to the speed required by the focus actuator so that it can continue to follow the motion trajectory 3 in subsequent trajectory segments.

[0167] In this diagram, the jump sections 10a-10f are represented by dotted lines. Within jump sections 10a-10f, processing of objects 1a and 1b does not occur. The laser can be turned off within jump sections 10a-10f.

[0168] Figure 7 An example of a local trajectory of a position-dependent adaptive focus curve 8 planned along an exemplary motion trajectory s(t) is shown, where the piecewise curvature of the curve is minimized. Processing segments 9a-9c and jump segments 10a, 10b are plotted within the position-dependent adaptive focus curve 8, where object 1 is processed using the focal position of laser focus 5 belonging to the position-dependent adaptive focus curve 8. In jump segments 10a, 10b, the laser is turned off or can be turned off, so object 1 is not processed. Alternatively, in jump segments 10a, 10b, the laser can also be used at low power, thus preventing processing.

[0169] In the region where the position-dependent adaptive focus curve 8 rises, for example, in the region near the end of the first processing section 9a, the laser focus 5 moves further toward the object 1 to compensate for the object's descent caused by the curvature of the object 1 and to keep the laser focus 5 in the motion trajectory 3 and / or on the object 1.

[0170] In this example, the first jump section 10a connects to the connection point 33. On object 1, two adjacent processing sections 9a and 9b are adjacent to each other. For example, the two processing sections 9a and 9b are Figure 6 The two diagonal lines of the letter "A". Therefore, the first jump segment 10a, for example, connects to the tip of "A" or... Figure 6 The connection point is 33a. The second jump section 10b connects two mutually spaced processing sections 9b and 9c on object 1. This is especially evident in the focal position jump of the position-dependent adaptive focal curve 8.

[0171] Furthermore, it can be seen that the location-dependent adaptive focus curve 8 is within the tolerance range 11.

[0172] like Figure 7 As shown, after determining the position-dependent adaptive focus curve 8 and fitting it to the tolerance range with at least a basic minimum curvature, the velocity curve 12 along the motion trajectory 3 can be specified in subsequent planning steps, thereby also specifying the time curve of the motion trajectory s(t).

[0173] List of reference numerals 1. Object 2. Laser beam 3. Movement trajectory 4. Galvanometer Scanning System 5. Laser Focus 6. Laser propagation direction 7. Idealized focal curve z with position dependence soll 8. Location-dependent adaptation focus curves 9 Processing Sections 10 Jump Section 11 Tolerance Range 12 Position-dependent velocity curves 13 Location-dependent power curves 14 First serpentine section 15 Second serpentine section 16 Focus Actuators 17 Calculation Units 18 Telecentric Planar Optical Devices 19 Laser processing equipment 20 First deflecting mirror 21 Second deflecting mirror 22 Focusing device 23 Focusing Units 24 Lenses 25 Distance 26 Object Surface 27. Trajectory Starting Point 28. End of the trajectory 29. Position-dependent x-coordinate curves 30. Position-dependent y-coordinate curves 31. Location-dependent temperature profiles 32. Intermediate Section 33 Connection Points

Claims

1. A method, particularly a computer-implemented method, for laser processing planning and / or laser processing objects (1), wherein, The laser beam (2) of the laser can be guided along at least one preset motion trajectory (3) on the object (1) by means of the galvanometer scanning system (4), wherein the position-dependent idealized focal curve z is determined. soll (s)(7), the position-related idealized focus curve along the motion trajectory (3) presets the focus position of the laser focus (5) of the laser beam (2) in the laser propagation direction (6). Among them, the idealized focal curve z related to the position soll (s)(7) expands the tolerance range (11), and Among them, according to the idealized focal curve z related to the position soll (s)(7) determine the position-dependent adaptive focus curve (8) to at least comply with the dynamic limits of the focus actuator (16) used to set the focus position of the laser focus (5); and The location-dependent adaptive focus curve (8) is at least segmented within the tolerance range (11).

2. The method according to the preceding claim, characterized in that, The idealized focus curve z related to the position soll (s)(7) Smoothing to determine the location-related adaptive focus curve (8).

3. The method according to any one of the preceding claims, characterized in that, Determine the position-dependent adaptive focus curve (8) such that the piecewise curvature of the position-dependent adaptive focus curve (8) is minimized.

4. The method according to any one of the preceding claims, characterized in that, Based on the position-related adaptive focus curve (8), the position-related velocity curve (12) of the laser focus (5) is determined along the motion trajectory (3).

5. The method according to any one of the preceding claims, characterized in that, The position-dependent adaptive focus curve (8) and / or the position-dependent velocity curve (12) are designed such that the acceleration and / or jerk of at least the focus actuator (16) is limited and / or within the dynamic limits of the focus actuator (16).

6. The method according to any one of the preceding claims, characterized in that, Determine the position-related adaptive focus curve (8) and / or the position-related velocity curve (12) to comply with the thermal limit of the focus actuator (16) used to set the focus position of the laser focus (5).

7. The method according to any one of the preceding claims, characterized in that, When the location-dependent adaptive focus curve (8) is expected to violate the tolerance range (11), the location-dependent velocity curve (12) is reduced in at least these regions.

8. The method according to any one of the preceding claims, characterized in that, The position-dependent power curve (13) of the laser is determined along the motion trajectory (3), which is based on the position-dependent velocity curve (12) and / or the position-dependent adaptive focus curve (8) to achieve the planned energy input curve along the motion trajectory (3).

9. The method according to any one of the preceding claims, characterized in that, Based on the position-related adaptive focal curve (8) and / or the position-related velocity curve (12), especially by simulation prior to laser processing, the position-related temperature curve (31) of the focal actuator (16) is determined.

10. The method according to any one of the preceding claims, characterized in that, The motion trajectory (3) is planned to have at least one processing section (9) and at least one jump section (10), wherein the object (1) is processed with a laser in the processing section (9) and the laser is turned off in the jump section (10), wherein the at least one jump section (10) is adjacent to the at least one processing section (9), is connected to the processing section (9) at a connection point (33) and / or at least two processing sections (9) are interconnected.

11. The method according to any one of the preceding claims, characterized in that, The motion trajectory (3) is divided into at least two processing sections (9) so that in each processing section (9), the velocity curve (12) related to the position of the laser focus (5) along the corresponding processing section (9) can be determined to be constant.

12. The method according to any one of the preceding claims, characterized in that, The motion trajectory (3) is divided into at least two processing sections (9), such that in each of the at least two processing sections (9), the position-related velocity curves (12) of the laser focus (5) along the corresponding processing section (9) are different from each other, and the position-related velocity curves (12) in the jump section (10) are planned to connect the position-related velocity curves (12) of the processing sections (9).

13. The method according to any one of the preceding claims, characterized in that, In particular, in at least one processing section (9), the tolerance range (11) is specified as a value of 1% to 200%, especially 20% to 100%, of the laser Rayleigh length.

14. The method according to any one of the preceding claims, characterized in that, In particular, in at least one processing section (9) and / or at least one jump section (10), the tolerance range (11) specifies at least segmental constant and / or position-dependent tolerances.

15. The method according to any one of the preceding claims, characterized in that, In the jump section (10), the tolerance range (11) is expanded and / or disregarded.

16. The method according to any one of the preceding claims, characterized in that, In the at least one jump section (10), the position-dependent adaptive focus curve (8) arranged therein is planned to construct a transition of the position-dependent adaptive focus curve (8) of the adjacent processing section (9), especially a continuous transition and / or an operable transition.

17. The method according to any one of the preceding claims, characterized in that, Before and / or during laser processing of the object (1), a laser processing planning method is performed for a future segment of the motion trajectory (3), in particular determining the position-dependent idealized focal curve z. soll (s)(7), position-dependent adaptation focus curve (8), position-dependent velocity curve (12), position-dependent power curve (13) and / or position-dependent temperature curve (31).

18. The method according to any one of the preceding claims, characterized in that, If the tolerance range (11), the dynamic limit and / or thermal limit of the focal actuator (16) are violated, the laser processing plan will be repeated at least partially.

19. The method according to any one of the preceding claims, characterized in that, The method for laser processing planning and / or laser processing object (1) is executed by the computing unit (17).

20. A computer program, when executed by a computing unit (17), causes the computing unit to perform the method according to any one or more of the preceding claims.

21. A computer-readable storage medium containing a computer program, wherein, When the computer program is executed by the computing unit (17), it causes the computing unit to perform the method according to any one or more of the preceding claims.

22. A laser processing apparatus (19) for laser processing planning and / or laser processing object (1), comprising: Lasers are used for laser processing. A galvanometer scanning system (4) for guiding the laser beam (2) of the laser onto the object (1), wherein the galvanometer scanning system (4) includes a focus actuator (16) for setting the focus position of the laser focus (5) of the laser beam (2); and Calculation unit (17), Its features are, The computing unit (17) is configured to perform the method according to at least one of the preceding claims.

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