Abstract: The invention relates to a method for determining a focal position of a machining beam, in particular a laser beam, relative to a workpiece when machining the workpiece using the machining beam, having the following steps: receiving at least one spatially resolved image of a workpiece region to be monitored, said region comprising the cut edges of a cut gap formed during the machining process on the upper face of the workpiece, ascertaining a gap width of the cut gap on the upper face of the workpiece using the cut edges in the at least one spatially resolved image, and determining the focal position of the machining beam relative to the workpiece using the ascertained gap width. The invention also relates to a corresponding device.

Abstract: An imaging device for imaging a process zone of a laser machine tool includes an image sensor and an optical imaging system. The optical imaging system includes a system axis extending between the image sensor and the process zone, a first aperture spaced radially from the system axis and delimiting first light beams emitted from the process zone at a first imaging angle, a second aperture delimiting second light beams emitted from the process zone at a second imaging angle, and a first imaging lens arranged between the first and/or the second aperture and the image sensor and configured to image the first light beams and the second light beams on the image sensor. The first imaging angle is different from the second imaging angle. The optical imaging system is configured to image the first light beams spatially separately from the second light beams.

Abstract: A method for monitoring a process of cutting a workpiece with a laser beam includes irradiating a top side of the workpiece with a laser beam, and cutting through the workpiece with the laser beam with a cut from the top side of the workpiece to an underside of the workpiece, the underside of the workpiece being opposite the top side of the workpiece in a beam direction of the laser beam, thereby forming a cutting front and a kerf. The method further includes limiting a power of a part of the laser beam that has passed through the workpiece to a predetermined level. The part of the laser beam having passed through exits from the workpiece on the underside of the workpiece when cutting through the workpiece.

Abstract: A laser machining method includes defining at least one threshold value S0 with respect to a light-intensity-dependent first process variable F in at least one working range KAB or at a working point KAP, detecting a light-intensity-independent second process variable K during operation of a laser machine tool in the at least one working range KAB or at the working point KAP, determining a change in the first process variable F in the at least one working range KAB or at the working point KAP when process conditions change, and changing the at least one threshold value S0 to a second threshold value S0R according to the change of the first process variable F from a first value F0 to a second value F0R.

Abstract: A laser cutting method using a laser cutting machine includes a) cutting a workpiece using a laser cutting beam having a high power along a cutting line, b) scanning the cutting line on the workpiece using a laser scanning beam having a low power or using an illumination beam, and recording scanning data, c) changing at least one parameter of a plurality of parameters the laser cutting machine, repeating steps a) and b), and evaluating the scanning data with respect to the plurality of parameters of the laser cutting machine in a control device. The scanning of the cutting line on the workpiece using the laser scanning beam of the low power is carried out during a return travel of a laser machining head.

Abstract: A beam cutting method includes conducting at least one cutting procedure while capturing at least one quality parameter. The at least one cutting procedure is intermittently implemented with an operation not subject to a closed-loop control and intermittently implemented with an operation subject to the closed-loop control. The beam cutting method further includes defining a process window in a parameter space of at least one process parameter, and choosing the at least one process parameter within the process window during the operation not subject to the closed-loop control. The at least one process parameter is allowed to be outside of the process window during the operation subject to the closed-loop control. The beam cutting method further includes adapting the process window based on changes in the at least one process parameter during the operation subject to the closed-loop control and/or changes in the at least one quality parameter.

Abstract: A method determines at least one parameter for a process quality during a processing process. The method includes: processing a workpiece while moving a processing tool and the workpiece relative to one another; monitoring a region on the workpiece; determining the at least one parameter for the process quality based on the monitored region; and determining at least one position-dependent parameter for the process quality based on a plurality of measured values of the at least one parameter at a same processing position, or determining at least one direction-dependent parameter for the process quality based on the plurality of measured values of the at least one parameter in a same processing direction.

Abstract: A method for identifying disruptions during a machining process, more particularly during a cutting process, includes: machining, more particularly cutting, a workpiece while moving a machining tool, in particular a laser machining head, and the workpiece relative to one another, recording an image of a region on the workpiece to be monitored, the region to be monitored being an interaction region of the machining tool with the workpiece, and evaluating the image of the region to be monitored. For the purpose of identifying at least one disruption of the machining process, the presence or the lack of a local intensity drop in an intensity profile within the interaction region is detected, during the evaluation of the image, in an advancement direction of the machining process. There is also described an associated machining apparatus.

Abstract: A device for monitoring, in particular for closed-loop control, of a thermal cutting process carried out on a workpiece. The device includes a focusing unit for focusing a machining beam, in particular a laser beam, onto the workpiece for the formation of a kerf on the workpiece. The device also includes an image acquisition unit to generate at least one image of a region of the workpiece, and an evaluation unit configured to determine, based on the at least one image, at least one measured variable for the course of the gap width of the kerf in a thickness direction of the workpiece. The invention also relates to an associated method for monitoring, in particular for closed-loop control, of a thermal cutting process carried out on a workpiece.

Abstract: A method for monitoring, in particular for controlling, a cutting process on a workpiece, includes focusing a machining beam, in particular a laser beam, on the workpiece, detecting a region of the workpiece to be monitored, the region including an interaction region in which the machining beam interacts with the workpiece, and determining at least one characteristic variable of the cutting process, in particular of a kerf formed during the cutting process, on the basis of the detected interaction region. In a fusion cutting process, a cutting front length of a cutting front formed at the kerf is determined as a characteristic variable on the basis of the detected interaction region. A corresponding device for monitoring, in particular for controlling, a cutting process on a workpiece, is also provided.

Abstract: A method determines at least one parameter for a process quality during a processing process. The method includes: processing a workpiece while moving a processing tool and the workpiece relative to one another; monitoring a region on the workpiece; determining the at least one parameter for the process quality based on the monitored region; and determining at least one position-dependent parameter for the process quality based on a plurality of measured values of the at least one parameter at a same processing position, or determining at least one direction-dependent parameter for the process quality based on the plurality of measured values of the at least one parameter in a same processing direction.

Abstract: A device for monitoring, in particular for closed-loop control, of a thermal cutting process carried out on a workpiece. The device includes a focusing unit for focusing a machining beam, in particular a laser beam, onto the workpiece for the formation of a kerf on the workpiece. The device also includes an image acquisition unit to generate at least one image of a region of the workpiece, and an evaluation unit configured to determine, based on the at least one image, at least one measured variable for the course of the gap width of the kerf in a thickness direction of the workpiece. The invention also relates to an associated method for monitoring, in particular for closed-loop control, of a thermal cutting process carried out on a workpiece.

Abstract: The invention relates to a method for determining a focal position of a machining beam, in particular a laser beam, relative to a workpiece when machining the workpiece using the machining beam, having the following steps: receiving at least one spatially resolved image of a workpiece region to be monitored, said region comprising the cut edges of a cut gap formed during the machining process on the upper face of the workpiece, ascertaining a gap width of the cut gap on the upper face of the workpiece using the cut edges in the at least one spatially resolved image, and determining the focal position of the machining beam relative to the workpiece using the ascertained gap width. The invention also relates to a corresponding device.

Abstract: A method for detecting defect in a weld seam during laser welding. The method includes performing a two-dimensionally locally resolved detection of radiation that is emitted by a solidified molten mass that is adjacent to a liquid melting bath. The method also includes determining at least one characteristic value for heat dissipation in the solidified molten mass by evaluating the detected radiation along at least one profile-section of the solidified molten mass, and detecting a defect in the weld seam by comparing the at least one characteristic value with at least one reference value.

Abstract: A method for monitoring a processing region of a workpiece on which laser processing is being carried out, in which method the radiation emitted by the processing region is detected by a detector system in a space-resolved manner, wherein the radiation of the processing region is detected for each elemental area of the processing region imaged onto the detector system at least two wavelengths simultaneously. Accurate process monitoring may thereby be carried out.

Abstract: A method for detecting defect in a weld seam during laser welding. The method includes performing a two-dimensionally locally resolved detection of radiation that is emitted by a solidified molten mass that is adjacent to a liquid melting bath. The method also includes determining at least one characteristic value for heat dissipation in the solidified molten mass by evaluating the detected radiation along at least one profile-section of the solidified molten mass, and detecting a defect in the weld seam by comparing the at least one characteristic value with at least one reference value.

Abstract: A method for detecting defect in a weld seam during laser welding. The method includes performing a two-dimensionally locally resolved detection of radiation that is emitted by a solidified molten mass that is adjacent to a liquid melting bath. The method also includes determining at least one characteristic value for heat dissipation in the solidified molten mass by evaluating the detected radiation along at least one profile-section of the solidified molten mass, and detecting a defect in the weld seam by comparing the at least one characteristic value with at least one reference value.

Abstract: A course of a position of a positioning device is determined as a laser beam welds a workpiece at a focus area of the laser beam. The positioning device is configured to position the focus area of a laser beam on a workpiece such that a joint is formed on the workpiece. A course of the joint on the workpiece from the determined course of the position of the positioning device is estimated, and a deviation between the determined course of the position of the positioning device and the estimated course of the joint on the workpiece is calculated. The deviation represents a parameter related to the precision of the seam position control.

Abstract: The invention relates to a method for monitoring a processing region of a workpiece (10) on which laser processing is being carried out, in which method the radiation emitted by the processing region (11) is detected by a detector system (22) in a space-resolved manner, wherein the radiation of the processing region (11) is detected for each elemental area of the processing region (11) imaged onto the detector system at least two wavelengths simultaneously. Accurate process monitoring may thereby be carried out.

Abstract: A method for detecting defect in a weld seam during laser welding. The method includes performing a two-dimensionally locally resolved detection of radiation that is emitted by a solidified molten mass that is adjacent to a liquid melting bath. The method also includes determining at least one characteristic value for heat dissipation in the solidified molten mass by evaluating the detected radiation along at least one profile-section of the solidified molten mass, and detecting a defect in the weld seam by comparing the at least one characteristic value with at least one reference value.