Control unit for issuing a laser beam release in a laser system

Abstract

The invention relates to a control unit (100) for use in a laser system (1) for working a workpiece by means of a laser beam, wherein the control unit (100) is designed to capture, on the basis of at least one translation axis position, a translational position (x, y, z) of a working head (3), which translational position can be changed by means of a movement unit (2); to capture, on the basis of at least one rotation axis position, a rotational orientation (a, b, c) of the working head (3), which rotational orientation can be changed by means of the movement unit (2); and to issue or revoke a laser beam release for the application of the laser beam to the workpiece, the laser beam release depending conclusively on the translational position (x, y, z) and / or on the rotational orientation (a, b, c) of the working head (3). The invention also relates to a laser system (1) and to a method for applying a laser beam to a workpiece.

Description

[0001] Control unit for issuing a laser beam release in a laser system

[0002] Technical area

[0003] The disclosure relates to a control unit for use in a laser system for processing a workpiece using a laser beam. It further relates to a laser system and a method for applying a laser beam to a workpiece.

[0004] State of the art

[0005] Laser systems, especially multi-axis laser systems, have become an indispensable technology in many industries in recent years. They offer high precision and flexibility, enabling materials to be processed efficiently, for example, by cutting or welding. Due to the high energy density of a laser beam in a generic laser system, it is necessary to equip the laser system with laser protection. This is intended to prevent the laser beam from hitting an area outside its processing range, which could damage a protective cabin and endanger people in the surrounding area. Passive or active applications are used for laser protection. Passive laser protection is ensured, for example, by a protective cabin surrounding the laser system, which withstands the energy input from the laser beam for a certain period of time.Active laser protection is provided by a sensor-equipped laser protection system and is known, for example, from published patent application DE 10 2015219 369 A1. This discloses a safety device for a laser system with a multi-axis manipulator. Further prior art of this type is known from utility model DE 20 2005 007 140 U1 and published patent applications US 2018 / 0113434A1 and DE 10 2012 216632 A1.

[0006] Description of the Invention Based on the known prior art, it is an object of the present invention to provide an improved control unit for use in a laser system for processing a workpiece using a laser beam, as well as a method for applying a laser beam to a workpiece. This object is achieved by a control unit and a method having the features of the independent claims. Advantageous further developments emerge from the subclaims, the description, and the figures.

[0007] Accordingly, a control unit for use in a laser system for processing a workpiece using a laser beam is proposed. The control unit can have one or more control devices. A control device can be composed of electronic modules that control or regulate a specific function of the laser system. The control unit is configured to detect a translational position of a processing head, which can be changed by means of a movement unit, based on at least one translational axis position. The translational position can be specified in three-dimensional space using Cartesian coordinates x, y, z. It can therefore be composed of an x-position, a y-position, and a z-position. Each of these positions can have its own translational axis position. The translational position of the processing head can thus be detected based on three translational axis positions.The movement unit can have a drive, such as a linear drive, that changes at least one, in particular three translation axis positions to move the processing head, for example, to a position intended for a planned processing of the workpiece. The processing head can be a laser cutting head or a laser welding head. It can be moved in its translational position, for example, by means of a carriage. The processing head can have focusing optics with a focusing lens. This focuses the laser beam, which is connected, for example, via a deflection housing and a laser light cable to a laser source, such as a solid-state laser.

[0008] The control unit is further configured to detect a rotational orientation of the machining head, which can be changed by means of the movement unit, based on at least one rotational axis position. The rotational orientation can be specified via an angular position about the at least one rotational axis. The rotational orientation can be changed via two or three rotational axes to provide a multi-axis system, in particular a 5-axis laser system or a 6-axis laser system. Each of these rotational axis positions can be detected and result in the rotational orientation. The position and orientation of the machining head are composed of the translational position and the rotational orientation.The control unit is further configured to grant or revoke laser beam release for applying the laser beam to the workpiece, wherein the laser beam release depends, in particular, conclusively on a serial, thus two-stage, check of the translational position and the rotational alignment of the machining head. The serial check can, in two stages, first check a first condition, such as the presence of a translational condition, and - if this is present - a second condition, such as the presence of a rotational condition. If the laser beam release ultimately depends on the translational position and the rotational alignment of the machining head, the laser beam can be released solely based on the input variables of the translational axis position and the rotational axis position. The serial check can comprise both active querying and passive evaluation.During active querying, the control unit is continuously informed of the translational position and, if necessary, the rotational orientation, and, depending on this, grants a laser beam release. During passive evaluation, the control unit is informed of the translational position and / or the rotational rotation at least when the at least one translational axis position and / or the at least one rotational axis position are within a predetermined range or have exceeded a certain value, which is stored, for example, in the control unit. Depending on this, a laser beam release can be withdrawn.Depending on the result of the translational position test, the serial test may require the rotational alignment test or may be completed after the translational position test because the translational position alone determines whether or not a laser beam release should be granted.

[0009] The laser beam release can be a program command that the control unit sends to the laser to grant it permission to apply the laser beam to a position on the workpiece indicated by the processing head, or to revoke permission to apply the laser beam to a position on the workpiece indicated by the processing head. The indicated position on the workpiece can be detected via the translational position and the rotational orientation of the processing head, as well as via a workpiece geometry communicated to the control unit. The control unit can thus grant or revoke laser beam release in response to the position and orientation of the processing head being communicated to it based on at least one translational axis position and at least one rotational axis position.The serial test can be divided into three case groups: (i) If the translational position of the machining head lies outside a machining area, for example, this is communicated to the control unit based on the corresponding translation axis position, and the control unit does not grant laser beam release to the laser and the associated machining head, regardless of the rotational orientation of the machining head. (ii) If, however, the translational position lies within the machining area and within a protection zone, the rotational orientation must be checked in order to grant or revoke laser beam release. The protection zone can be adjusted depending on the laser power and / or a type of laser optics, a protective housing or cabin of the laser system, and / or an application of the laser system for machining the workpiece.The protection zone can represent a peripheral area of ​​the machining area, within which both the translational position and the rotational alignment must be checked. (iii) If the translational position lies within the machining area and outside the protection zone, the application of the laser beam is safe regardless of the alignment of the machining head. Accordingly, the control unit authorizes the laser beam to be used, regardless of the rotational alignment of the machining head. In this respect, a serial check is performed because the check of the rotational alignment depends on the result of the check of the translational position.

[0010] This ensures software-supported monitoring of the position and alignment of the processing head. It anticipates when the laser beam is directed at areas outside the processing area without relying on laser-sensitive sensors located outside or inside the processing area. This increases the safety of laser systems because the presence of a safety-impairing condition is detected and prevented before a laser beam can be harmfully impinged outside its processing area. Furthermore, a robust and error-resistant system is provided, since laser beam release can be granted or revoked based on the position and / or alignment. The control unit according to the disclosure enables an efficient and lean laser system with minimal hardware requirements for safe operation.

[0011] In one embodiment, the control unit is configured to test, during the serial test, a translational condition in which the translational position is within a predetermined translation range, and a rotational condition in which the rotational orientation is within a predetermined rotation range, wherein the predetermined rotation range varies depending on the translational position. For example, a first value of a rotational orientation can receive laser beam release at a first translational position, i.e., lie within the predetermined rotation range, and the same first value of the rotational orientation can not receive laser beam release at a second translational position, i.e., lie outside the predetermined rotation range. Laser beam release can only be granted when the translational condition and, cumulatively, the rotational condition are met.Because the rotational condition depends on the translational position, i.e., varies with it, the machining area is maximized and space utilization optimized. The translational position can be divided into three areas: (i) outside the machining area, where no laser beam clearance is granted; (ii) within the machining area but also within the protection area, where laser beam clearance is granted depending on the rotational orientation; (iii) within the machining area and outside the protection area, where laser beam clearance is granted regardless of the rotational orientation.

[0012] For example, if the control unit detects a translational position located at an outer edge of a machining area, such as within the machining area and within the protection area, the laser beam release is granted depending on the rotational orientation: If a rotational orientation, such as that around a rotation axis b, is inclined by 0°, for example, the notified position of the machining head is within the machining area and outside the protection area, which is why the laser beam release is granted or not withdrawn. If, on the other hand, the rotational orientation is inclined in an orientation facing away from the machining area, for example -10°, the notified position of the machining head is within the machining area and within the protection area, and the laser beam release is not granted or withdrawn accordingly.With the same values ​​of the rotational directions and different translational positions, the laser beam release can vary. This dynamic adjustment of the laser beam release enables high flexibility in the position and orientation of the processing head. Furthermore, the installation space of the laser system is minimized, which is particularly advantageous when the laser system comprises several work areas adjacent to one another, such as in a two-station operation. The dynamic adjustment of this embodiment also enables an adaptable balance between i) the largest possible processing space for the laser beam and (ii) the simplest possible query of the laser beam release. This also increases the reliability of the granted laser beam release.

[0013] In one embodiment, the predetermined translation range and / or the predetermined rotation range are stored in the form of an array in a memory area of ​​the control unit. An array can enable the storage of multiple values ​​in one variable. Individual arrays and values ​​defined therein, for example, an array of the predetermined translation range, can be logically linked to other arrays and values ​​defined therein, for example, an array of the predetermined rotation range. A first array can be checked first, and then a second array can be checked in an AND combination. Instead of an array, a safe software cam can also be used, which can be processed using safe logic. It is also possible to store the predetermined translation range and / or rotation range in the form of at least one lookup table.For example, the lookup table can list the rotational directions for the translational positions in the protection area for which a laser beam release must be granted.

[0014] When the machining head assumes a corresponding position, a low-computing comparison with the array (or the safe software cam or the lookup table) can be used to determine whether laser beam release should be granted or revoked. There can also be multiple arrays or multiple values ​​within the same array depending on the various translational positions and / or the various operating factors, such as the laser power, the type of laser optics, the existing protective cabin and / or the application of the laser system for machining the workpiece. The number of arrays or values ​​within the same array can determine the maximum machining space within which laser beam release is granted and the computing power required to issue laser beam release. As the array size increases, the machining space and with it the computing power required for laser beam release increase.The arrays can therefore be used to adapt the laser system's performance characteristics to suit specific applications.

[0015] In one embodiment, the predetermined translation range and / or the predetermined rotation range are determined in a training phase preceding an operating phase. The training phase can be carried out on the laser system itself or at least partially on a simulation. It serves to determine the positions and directions in which a laser beam release should or should not be granted. For example, for each translational position, a plurality of rotational directions can be controlled in order to maximize the range for which a laser beam release should be granted. The training phase can serve to determine the optimal ratio of processing space to required computing power.

[0016] In one embodiment, the predetermined translation range and / or the predetermined rotation range depend on at least one of (i) a laser power, which may, for example, be between 3 and 8 kW, and / or a type of laser, such as a high-power solid-state laser, or a type of laser optics; (ii) a protective cabin of the laser system; (iii) an application of the laser system for processing the workpiece, such as welding, for example deep penetration welding; and / or laser cutting and / or 3D laser processing; and / or (iv) optical parameters for beam shaping. The adaptability of the laser beam release to external parameters increases the flexibility of the control unit and the laser system.

[0017] In one embodiment, acquisition communication between the motion unit and the control unit for acquiring the translational position and the rotational orientation takes place via a fail-safe acquisition path. A fail-safe path is implemented using safe transmission technology and, in particular, enables safety-related motion monitoring and / or a fail-safe programmable logic controller (PLC). It meets strict safety requirements. In particular, the fail-safe path meets the strict safety requirements according to (i) Safety Class 2 (Safety Integrity Level 2, SIL 2) according to IEC 61508, (ii) Performance Level d (PL d) according to DIN EN ISO 13849-1, and / or (iii) Category 3 according to DIN EN ISO 13849-1. Fail-safe position acquisition can be implemented, for example, using a single channel via an encoder with a serial interface.The fail-safe path uses safe communication and distinguishes itself from unsafe paths using non-safe technology by automatically detecting errors present in the path and triggering an alarm if necessary. The acquisition communication therefore does not rely on a non-safe programmable logic controller (PLC), which increases its safety. The acquisition communication can take place between the motion unit and a dedicated control device within the control unit and is independent of other paths. This enables error-resistant communication of the translational axis position and the rotational axis position. Thus, the highest safety standards can be met even without error-sensitive sensors.

[0018] In one embodiment, release communication between the control unit and the movement unit for communicating a granted laser beam release takes place via a fail-safe release path. The release communication therefore does not rely on a non-safe PLC, which increases its safety. The release communication can take place between a dedicated control unit within the control unit and the movement unit and be independent of other paths. A redundant control unit can therefore be provided within the control unit to minimize the probability of errors in the release communication.

[0019] In one embodiment, motion communication takes place between the control unit and the motion unit for changing the translational position and the rotational orientation via a motion path, wherein the detection path and / or the release path are implemented independently of the motion path. The motion path can therefore be designed as a single-channel system and, unlike the detection path and / or the release path, can be implemented using non-safe technology. For example, the motion path, the detection path, and / or the release path can each have their own control devices within the control unit so that they are independent of one another. The detection communication and the release communication can take place using safe technology, while the motion communication can be PLC- or NC-controlled using non-safe technology.

[0020] In one embodiment, the control unit is configured to detect the translational position via at least one software cam of the translational axis position and / or to detect the rotational orientation via at least one software cam of the rotational axis position. A software cam is a position of a machine axis stored in the control unit, for example, the at least one, in particular each, translational and rotational axis, to which a function is assigned. When the position of the machine axis is reached, a corresponding signal is sent. For example, software cams can be used as a travel limit for the at least one, in particular each, translational and rotational axis.Reaching an axis position identified by the software cam can trigger a rotation stop function within the control unit, which then prevents further rotation of the machine axis by the motion unit or machining head. The software cams can also be used to enable the laser beam. Reaching an axis position identified by the software cam triggers a laser beam release stop function within the control unit, which then either denies or revokes the laser beam release. The software cams can be set and activated according to the translational condition and / or the rotational condition.

[0021] In one embodiment, the control unit comprises a first control unit for controlling the movement unit and / or the processing head and a second control unit for granting or revoking laser beam release, with the first control unit being independent of the second control unit. This increases the redundancy of the laser system and thus also its operational reliability. The individual control units can communicate with each other.

[0022] The disclosure further relates to a laser system for machining a workpiece using a laser beam, comprising a control unit according to the disclosure and a machining head for aligning the laser beam onto the workpiece, wherein the machining head assumes the translational position determined by at least one translational axis position and the rotational orientation determined by at least one rotational axis position, and wherein the machining head is configured to apply the laser beam only with a laser beam release. The laser system further comprises a movement unit for changing the translational position and the rotational orientation. The laser system can have the features disclosed in connection with the control unit. In one embodiment, the translational axis position of the laser system is determined by three linear axes and / or the rotational axis position is determined by one, two, or three rotational axes.Such a four-, five-, or six-axis laser system is a 3D laser system that can variably move the processing head. The control unit according to the disclosure ensures that the laser system is operated using safe technology, for example, using software cams.

[0023] In one embodiment, the laser system has a first work area for processing a first workpiece and a second work area for processing a second workpiece in order to implement two-station operation. In this case, the movement unit is configured to move the processing head between the first work area and the second work area. This allows a workpiece to be initially processed in the first work area and then the processing head to be moved to the second work area to process a second workpiece while, for example, a workpiece is being exchanged in the first work area. This guarantees time-efficient processing for high volumes. A separating device for shielding the operator from laser radiation is provided between the first work area and the second work area.The separation device serves to shield a laser beam directed from the first work area to the second work area. The separation device can be provided in addition to and within the protective cabin surrounding the laser system.

[0024] In one embodiment, the separating device is designed as a partition wall whose height is, at least in sections, sufficiently large to provide a shield between the first and second work areas, and sufficiently small to allow movement of the machining head between the first work area and the second work area. The partition wall can have a movable separating flap. This can be extendable and retractable in an area in which the machining head moves between the first work area and the second work area. In the extended state, it can be flush with an upper edge of the partition wall. In the retracted state, it provides a recess within the partition wall through which the machining head moves when moving from one work area to the other.The separating flap therefore enables, on the one hand, a maximum area of ​​the partition wall for maximum safety, and, on the other hand, a flexible movement of the machining head in two-station operation.

[0025] In one embodiment, a first scanner field is defined for the first work area and a second scanner field is defined for the second work area. The respective scanner field defines the area that is to be protected from the laser beam from the adjacent work area, for example because an operator may be present there when changing the workpiece. The distance from the scanner field to the potential laser radiation can be designed such that a switch-off time of the laser beam is taken into account. The control unit is configured to check during the serial test whether, when the processing head is in the first work area, the laser beam is directed at the second scanner field and / or when the processing head is in the second work area, the laser beam is directed at the first scanner field, in order to only issue a laser beam release if the laser beam is not directed at the corresponding scanner field.The control unit can therefore be configured to deny or revoke the laser beam release for applying the laser beam to the workpiece when the machining head is in the first work area and the laser beam is directed at the second scanner field, or when the machining head is in the second work area and the laser beam is directed at the first scanner field. The scanner field and the partition wall can thus increase safety in two-station operation.

[0026] The disclosure also relates to a method for applying a laser beam to a workpiece, comprising the following steps:

[0027] Detecting a translational position of a motion unit based on at least one translational axis position and a rotational orientation of the motion unit based on at least one rotational axis position. Detecting can occur continuously or only when the translational axis position and / or the rotational axis position are within a certain range, for example, when they exceed or fall below a certain value. Furthermore, the translational positions of three translational axes, such as axes for linear movement, and the rotational orientation of two or three rotational axes can be detected.

[0028] Checking a translational condition to determine whether the translational position lies within a predetermined translation range. The check can be configured to detect whether the position is within the release range or to detect whether the position has left the release range. The former involves active querying, the latter involves passive evaluation, as explained above in connection with the control unit. Checking a rotational condition to determine whether the rotational orientation lies within a predetermined rotation range. The rotational condition can be checked cumulatively after the translational condition. In particular, it can only be checked if the translational condition gives rise to it, as explained above in connection with the control unit.

[0029] Granting a laser beam release when the translational and rotational conditions are present, whereby the laser beam can only be applied to the workpiece with the laser beam release. In this way, the machining head is unable to apply a laser beam to the workpiece if there is no laser beam release or if the laser beam release has been revoked.

[0030] This method enables software-supported monitoring of the position and alignment of the machining head. Similar to the control unit, it anticipates when the laser beam is directed at areas outside the machining area, without relying on laser-sensitive sensors located outside or inside the machining area. This increases the safety of laser systems because the presence of a safety-impairing condition is detected and prevented before a laser beam can be harmfully impacted outside its machining area. Furthermore, a robust and error-resistant system is provided, since laser beam release can be granted or revoked based on the position and / or alignment. This method enables an efficient and lean laser system with minimal hardware requirements for safe operation.

[0031] In one embodiment of the method, the presence of the rotational condition varies with the translational position. Because the rotational condition depends on the translational position, the processing area is maximized and space utilization is optimized. The translational position can be divided into three areas: (i) outside the processing area, where no laser beam release is granted; (ii) within the processing area but also within the protection area, where laser beam release is granted depending on the rotational orientation; (iii) within the processing area and outside the protection area, where laser beam release is granted regardless of the rotational orientation, as explained above in connection with the control unit. The method according to the disclosure can be carried out on the laser system according to the disclosure with the control unit.The features, effects and advantages disclosed above in connection with the control unit or the laser system can therefore be applied accordingly to the method insofar as they apply accordingly to method steps.

[0032] Short description of the characters

[0033] Preferred further embodiments of the invention are explained in more detail in the following description of the figures. In the figures:

[0034] Figure 1 is a side view of a laser system according to the disclosure;

[0035] Figure 2 shows a further side view of a laser system according to the disclosure;

[0036] Figure 3 shows a further side view of a laser system according to the disclosure with a position in which a laser beam release is issued and a position in which no laser beam release is issued;

[0037] Figure 4 shows a further side view of a laser system according to the disclosure with a position in which a laser beam release is issued and a position in which no laser beam release is issued;

[0038] Figure 5 is a flowchart of a serial test according to the disclosure;

[0039] Figure 6a shows a further side view of a laser system according to the disclosure in two-station operation, in a first operating state in which a release is granted; and

[0040] Figure 6b shows the side view from Figure 6a in a second operating state in which no release is granted or the release is withdrawn.

[0041] Detailed description of preferred embodiments

[0042] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the different figures are provided with identical reference numerals, and a repeated description of these elements is partially omitted to avoid redundancies.

[0043] Figure 1 schematically shows a laser system 1 for machining a workpiece using a laser beam. The laser system 1 has a control unit 100 comprising one or more control devices that are at least partially connected to one another. A movement unit 2 is configured to move a machining head 3, thus changing its translational position, which can be determined using Cartesian coordinates x, y, z, and its rotational orientation, which can be determined via angular ranges around rotation axes a, b, c. The machining head 3 can, for example, comprise laser optics. It serves to focus laser radiation supplied via a fiber optic cable, for example, onto the workpiece or to image it thereon in order to machine the workpiece using the laser radiation.A release of the laser beam for exposure to the workpiece may be provided to ensure the safety of the surrounding areas. Areas here refer to spatial areas.

[0044] Accordingly, the processing head 3 only applies the laser beam to the workpiece when a laser beam release is present. For example, a laser beam release can be actively granted before each laser beam ignition. Alternatively, a laser beam release can be revoked if the laser beam would be applied to an inadmissible area. The laser beam release for applying the laser beam to the workpiece depends on a serial check of the translational position and the rotational position of the processing head 3.

[0045] The control unit 100 detects a translation axis position of at least one, in particular each of the x, y, z axes, which determine the translational position. A pair of software cams is provided in at least one, in particular each x, y, z axes. A software cam indicates a position of a machine axis to which a specific function is assigned. Thus, the control unit can prevent further movement or rotation of the axis when the translation axis position reaches a software cam. Accordingly, the control unit 100 also detects a rotation axis position of at least one, in particular each of the a, b, c axes, which determine the rotational orientation. A pair of software cams is provided in at least one, in particular each a, b, c axes.

[0046] The serial testing of the translational position and rotational orientation first checks for the existence of a translational condition where the translational position is within a predetermined translation range. The translational condition can be checked for each of the three translational axes x, y, and z. This testing of the translational condition of the translational axes x, y, and z can run in parallel. Alternatively, it can run serially, so that first the translational condition of the x-axis is checked, followed by the translational condition of the y-axis, and then the translational condition of the z-axis. The testing of the translational condition can be divided into three groups of cases, which are shown below using the x-axis as an example. The teachings of these groups of cases can be applied analogously to the y-axis and the z-axis.

[0047] (i) At x = 0, the machining head 3 is in the central position. This position x = 0 is within the machining area and outside a protection zone. The protection zone can represent an edge area of ​​the machining area, within which, in addition to the translational position, the rotational alignment must also be checked. The protection zone can be adjusted in the control unit. The translational condition of the x-position for the laser beam release is met because the translational position is within the machining area. If the translational condition of the y-position and the z-position is also met such that the respective position is within the machining area and outside the protection zone, the control unit 100 issues a laser beam release regardless of the rotational alignment of the machining head 3 (see also Figure 5).

[0048] (ii) At x = + / - x1, a protection zone of the x-position begins. This zone extends to the position x = + / - x2. If the machining head 3 is within the protection zone of the x-position, a rotational condition is checked. This checks for the existence of a rotational condition in which the rotational orientation is within a predetermined rotation range. The rotational condition is checked serially after the translational condition (see also Figure 5).

[0049] (iii) If x > |x2|, the machining head is located outside the protection zone and outside the machining zone. Regardless of the other conditions, i.e., the translational condition of the y-axis and the z-axis, as well as the rotational condition, no laser beam clearance is granted outside the machining zone (see also Figure 5).

[0050] The rotational alignment is checked serially after the translational position. If all three translational positions, i.e. the x-position, the y-position, and the z-position, fall into the above case group (i), the rotational alignment is not checked because the machining head 3 is located within the machining area and outside the protection area, and therefore laser beam clearance is granted anyway. If at least one of the translational positions falls into the above case group (iii), the rotational alignment is also not checked because the machining head 3 is located outside the machining area, and therefore laser beam clearance is not granted anyway. However, if the translational position falls into the above case group (ii), checking the rotational alignment is required to grant or withdraw laser beam clearance.Depending on the translational position of the machining head 3 within the above case group (ii), i.e., within the protected area, the rotational alignment at which a laser beam release is granted or withdrawn varies. In this respect, a serial check is performed because the check of the rotational alignment depends on the result of the check of the translational position.

[0051] Figure 2 shows the laser system 1 from a different direction. The processing head 3 has an offset along the y-direction. The laser system 1 is a 3D laser system. The processing head 3 can be moved translationally in all three spatial directions x, y, and z by means of the motion unit 2, for example, using a linear drive. Furthermore, the processing head 3 can be rotated about rotational axes, for example, about three rotational axes a, b, and c or about two rotational axes b, c, using the motion unit 2. The laser system 1 thus achieves maximum flexibility in the application of the laser beam to the workpiece, for example, for laser welding and / or laser cutting. Therefore, versatile workpiece geometries can be processed in flexible shapes.

[0052] Figure 3 shows an example of how the laser beam release in the above case group (ii), i.e. in the protection zone, depends on the rotational orientation of the processing head 3. A translational x-position of the processing head 3 lies between a value x1 and x2. The processing head 3 is therefore located in the x-direction within the processing zone and within the protection zone. If the processing head 3 assumes the angle b1 in the rotational orientation around the rotation axis b, which protrudes from the plane of the drawing, the laser beam reaches the processing zone. Accordingly, for this case b = b1, a laser beam release is granted or not withdrawn. If, on the other hand, the processing head 3 assumes the angle b2 in the rotational orientation around the rotation axis b, the laser beam is outside the processing zone. Accordingly, for this case b = b2, a laser beam release is not granted or withdrawn.In a third case, the processing head 3 could also assume an angle of b = 0 in its rotational orientation around the rotation axis b. In this case, the laser beam passes entirely within the protection zone. In this case, a laser beam release can be granted optionally. For example, the critical values ​​for x and b can be determined such that, when the laser beam hits the protective cabin, a predetermined minimum service life of the protective cabin is not exceeded.

[0053] In this way, the application range of the laser beam is increased because, thanks to the serial testing, laser beam release can be granted even within the protection zone depending on the rotational alignment. The position x = x1 represents the x-software cam. From this position, the control unit 100 is informed, based on the translation axis position of the x-axis, that the processing head 3 is located in the protection zone. The software cam is thus used not only for path limitation but also for laser beam release. Corresponding to the x-axis, all other axes of the multi-axis laser system 1 also have corresponding software cams that are used for laser beam release. In one embodiment, the z-axis can also be designed without software cams.If the processing head 3 is moved by the movement unit 2 along the x-direction into a range between x = 0 and x < x1, the above case group (i) applies, in which a laser beam release is granted regardless of the rotational orientation. If the processing head 3 is moved by the movement unit 2 along the x-direction into a range x > x2, the above case group (iii) applies, in which a laser beam release is not granted regardless of the rotational orientation.

[0054] Figure 4 shows the laser system 1 in another operating state. The processing head 3 is located along the z-translation axis at a position z that lies within the positions z1 and z2, thus within the protection zone of the z-axis. In this position, the above case group (ii) is relevant, in which the rotational alignment must be checked for laser beam release. The illustration shows a pivoting of the processing head 3 around the b-axis. If the processing head 3 rotates by b3 = 90° in the z-position shown, the laser beam is within the protection zone and therefore receives laser beam release. If, however, the processing head 3 rotates by b4 equal to 94.2° in the z-position shown, the laser beam is outside the protection zone and therefore does not receive laser beam release. The rotational alignment b3 = 90° represents a software cam of the b-axis.From this position, the control unit 100 is informed, based on the rotation axis position of the b-axis, that the machining head 3 is located in the protection zone. The software cam is thus used not only for path limitation but also for laser beam release. If the machining head 3 is moved by the movement unit 2 along the z-direction into a range between z = 0 and z < z1, the above case group (i) applies, in which a laser beam release is granted regardless of the rotational orientation. If the machining head 3 is moved by the movement unit 2 along the z-direction into a range z > z2, the above case group (iii) applies, in which a laser beam release is not granted regardless of the rotational orientation.

[0055] Figure 5 shows a flow chart of the serial test. In field 101, a translational

[0056] Condition checked. When checking the translational condition, it is queried whether a translational position of the machining head 3 is within a predetermined translational range. This test can be carried out in parallel for each translational direction x, y, z; in particular, it can also be carried out only for the x-direction or only for the x and y directions. Alternatively, this test can serially check first the first, then the second, then the third translational direction. Depending on the result of the translational condition, further steps can follow. If at least one of the translational positions x, y, z is outside the machining range, i.e. greater than x2 or y2 or z2, step 102, no laser beam release is issued, field 103. If, on the other hand, every translational position x, y, z is within the machining range and outside the protection range, i.e. smaller than x1 or y1 orz1, step 104, a laser beam release is granted, field 105. For steps 102, 104, no check of the rotational alignment is required because the translational position already determines whether or not a laser beam release should be granted. The serial check is thus already completed. If at least one of the translational positions x, y, z is in the protection area, i.e. between x1 and x2 or y1 and y2 or z1 and z2, step 106, a rotational condition must be checked, field 107. Depending on which of the three translational positions x, y, z is in the protection area and depending on which translational position value the respective translational position assumes within the protection area, the predetermined rotation range within which the rotational alignment can lie in order to fulfill the rotational condition varies.The rotation range, which varies with the translational position, is stored, for example, as an array in a memory area of ​​the control unit 100. It can be determined in a training phase prior to the operating phase of the control unit 100 and can vary depending on external factors, such as the laser power and / or the type of laser optics, a protective cabin of the laser system and / or an application of the laser system for processing the workpiece. The check of the rotational alignment either shows that the rotational condition is not met, step 108, which is why no laser beam release is granted, field 103. Alternatively, the check of the rotational alignment shows that the rotational condition is met, step 109, which is why a.

[0057] Laser beam release is granted, field 105. If, for example, the processing head 3 assumes a new translational position and rotational orientation and the control unit 100 detects this position and orientation based on the respective axis positions, the sequence from Figure 5 can start again from the beginning.

[0058] Figures 6a and 6b show the laser system 1 in two-station operation. In two-station operation, the laser system 1 has a first work area 4 and a second work area 5. At least one workpiece can be machined in each work area 4, 5. A partition wall 6 is arranged as a separating device between the first work area 4 and the second work area 5. The machining head 3 can be moved between the first work area 4 and the second work area 5. In the state shown in Figure 6a, the machining head 3 is located along the z-translation axis at a position z that lies within the positions z1 and z2, thus within the protection zone of the z-axis. In this position, the above case group (ii) is relevant, in which the rotational alignment must always be checked for laser beam release.In two-station operation, in addition to the rotational alignment, another criterion can be checked during the serial test, namely whether the laser beam is directed onto an adjacent scanner field 7.

[0059] In Figure 6a, the processing head 3 assumes a rotational orientation such that the laser beam is directed at the partition wall 6. The laser beam therefore does not reach the adjacent scanner field 7, which is why a temporary laser beam release can be granted. In the operating state shown in Figure 6b, the processing head 3 is still arranged in the protection zone of the z-axis. The rotational orientation, however, is such that the laser beam extends beyond the partition wall 6 into the adjacent scanner field 7. In this case, a laser beam release cannot be granted or withdrawn during serial testing. This guarantees that, in two-station operation, no laser beam reaches the currently processing-free work area.

[0060] In two-station operation, a laser beam emanating from the processing head 3 can strike the partition 6 within the first work area 4. This prevents the laser beam from entering the scanner field 7 of the adjacent, second work area 5, and a laser beam release can be issued. The partition 6 can have a movable partition flap 8 in the area in which the processing head 3 moves between the first work area 4 and the second work area 5. This is extended in an operating state in which the processing head 3 is in the first work area 4 or the second work area 5, thus creating a maximum area of ​​the partition 6. In an operating state in which the processing head 3 moves between the work areas 4, 5, the partition flap 8 is retracted, thus releasing an area that enables the processing head 3 to move between the first work area 4 and the second work area 5.

[0061] In Figure 6b, the separating flap 8 is extended, just as in Figure 6a, so that the area of ​​the partition wall 6 is maximized. In Figure 6b, the processing head 3 assumes a position such that the laser beam passes over the partition wall 6 with the separating flap 8 extended from the first work area 4 into the second work area 5. The laser beam enters the second scanner field 7, so that, as described above, no laser beam release can be granted. In this way, in two-station operation, the greatest possible flexibility in the position and orientation of the processing head 3 is combined with the greatest possible safety.

[0062] Where applicable, all individual features shown in the embodiments can be combined and / or exchanged.

[0063] List of reference symbols

[0064] 1 laser system

[0065] 2 movement units

[0066] 3 processing head

[0067] 4 First work area

[0068] 5 Second work area

[0069] 6 Partition wall

[0070] 7 Scanner field

[0071] 8 Dividing flap

[0072] 100 control unit

[0073] 101-109 Test steps and test results of the sequential test x, y, z Translation axes a, b, c Rotation axes b1-b4 Rotational directions around the b-axis

Claims

Claims 1. A control unit (100) for use in a laser system (1) for machining a workpiece using a laser beam, wherein the control unit (100) is configured to detect a translational position (x, y, z) of a machining head (3), which can be changed by means of a movement unit (2), based on at least one translational axis position; to detect a rotational orientation (a, b, c) of the machining head (3), which can be changed by means of the movement unit (2), based on at least one rotational axis position; and to grant or withdraw laser beam release for applying the laser beam to the workpiece, wherein the laser beam release depends on a serial check of the translational position (x, y, z) and the rotational orientation (a, b, c) of the machining head (3), in particular conclusively.

2. Control unit (100) according to claim 1, which is configured to test, during the serial test, a translational condition in which the translational position (x, y, z) is within a predetermined translation range, and a rotational condition in which the rotational orientation (a, b, c) is within a predetermined rotation range, wherein the predetermined rotation range varies depending on the translational position (x, y, z).

3. Control unit (100) according to one of the preceding claims, wherein the predetermined translation range and / or the predetermined rotation range are stored in the form of an array in a memory area of ​​the control unit (100).

4. Control unit (100) according to one of the preceding claims, wherein the predetermined translation range and / or the predetermined rotation range were determined in a training phase preceding an operating phase.

5. Control unit (100) according to one of the preceding claims, wherein the predetermined translation range and / or the predetermined rotation range are dependent on at least one of a laser power and / or a type of laser optics, a protective cabin of the laser system (1), and / or an application of the laser system (1) for processing the workpiece.

6. Control unit (100) according to one of the preceding claims, wherein a detection communication between the movement unit (2) and the control unit (100) for detecting the translational position (x, y, z) and the rotational orientation (a, b, c) takes place by means of a detection path that is fail-safe.

7. Control unit (100) according to one of the preceding claims, wherein a release communication between the control unit (100) and the movement unit (2) for communicating a granted laser beam release takes place by means of a release path which is fail-safe.

8. Control unit (100) according to one of claims 6 or 7, wherein a movement communication between the control unit (100) and the movement unit (2) for changing the translational position (x, y, z) and the rotational orientation (a, b, c) takes place by means of a movement path, wherein the detection path and / or the release path is implemented independently of the movement path.

9. Control unit (100) according to one of the preceding claims, which is configured to detect the translational position (x, y, z) via at least one software cam of the translation axis position and / or to detect the rotational orientation (a, b, c) via at least one software cam of the rotation axis position.

10. Control unit (100) according to one of the preceding claims, comprising a first control device for controlling the movement unit (2) and / or the processing head (3) and a second control device for granting or withdrawing the laser beam release, wherein the first control device is independent of the second control device.

11. Laser system (1) for machining a workpiece by means of a laser beam, comprising the control unit (100) according to one of the preceding claims; the machining head (3) for aligning the laser beam onto the workpiece, wherein the machining head (3) assumes the translational position (x, y, z) determined by at least one translational axis position and the rotational orientation (a, b, c) determined by at least one rotational axis position, and wherein the machining head (3) is configured to apply the laser beam only with a laser beam release; and the movement unit (2) for changing the translational position (x, y, z) and the rotational orientation (a, b, c).

12. Laser system (1) according to claim 11, wherein the translation axis position is determined by three linear axes and / or the rotation axis position is determined by two or three rotation axes.

13. Laser system (1) according to one of claims 11 to 12, with a first working area (4) for processing a first workpiece and a second working area (5) for processing a second workpiece, wherein the movement unit (2) is designed to move the processing head (3) between the first working area (4) and the second working area (5), wherein a separating device for partial shielding is provided between the first working area (4) and the second working area (5).

14. Laser system (1) according to claim 13, wherein the separating device is designed as a partition wall (6) whose height is at least partially sufficiently large to provide the shielding between the first working area (4) and the second working area (5), and is sufficiently small to enable the movement of the processing head (3) between the first working area (4) and the second working area (5), wherein the partition wall (6) in particular has a movable separating flap (8).

15. Laser system (1) according to one of claims 13 or 14, wherein a first scanner field is defined for the first working area (4) and a second scanner field (7) is defined for the second working area, wherein the control unit (100) is configured to check during the serial test whether, when the processing head (3) is in the first working area (4), the laser beam is directed onto the second scanner field (7) and / or when the processing head (3) is in the second working area (5), the laser beam is directed onto the first scanner field; in order to only issue a laser beam release if the laser beam is not directed onto the corresponding scanner field.

16. A method for applying a laser beam to a workpiece, comprising the steps of: Detecting a translational position (x, y, z) of a movement unit (2) based on at least one translation axis position and a rotational Alignment (a, b, c) of the movement unit (2) based on at least one rotation axis position; Checking a translational condition, whether the translational position (x, y, z) lies within a predetermined translation range; - Checking a rotational condition, whether the rotational orientation (a, b, c) lies within a predetermined rotation range; Issuing a laser beam release when the translational condition and the rotational condition are present, wherein the laser beam can only be applied to the workpiece with the laser beam release.

17. The method according to claim 16, wherein the presence of the rotational condition varies with the translational position (x, y, z).

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