Laser processing head with laser radar sensor

Abstract

The invention relates to a laser machining head (1) for machining a workpiece (4) with a laser beam (3), comprising: a housing (2) in which a focusing optical device (9) for focusing the laser beam (3) is arranged; and at least one lidar sensor (11, 12, 13) for detecting the distance between the laser machining head (1) and an object in the process space; wherein the lidar sensor (11, 12, 13) is arranged externally on the housing (2), and the beam path of the lidar sensor (11, 12, 13) extends outside the housing (2).

Description

Technical Field

[0001] The present disclosure relates to a laser processing head for processing a workpiece using a laser beam, which includes at least one lidar sensor for detecting objects in the surrounding environment. Background Art

[0002] When processing a workpiece using a laser beam, i.e., in a laser processing process, the laser beam is typically guided along a processing path by the relative movement between the laser processing head emitting the laser beam and the workpiece.

[0003] During laser cutting and laser welding processes, the higher the laser power, the faster the processing speed, which greatly increases the requirements for controlling and / or regulating the processing process and also increases the potential risks brought by high laser power. In particular, due to the increasingly short response time, collisions that may occur will cause more serious consequences, so the requirements for preventing collisions are also getting higher and higher. Therefore, it is very advantageous to perform optical measurement on the surrounding environment of the laser processing head to detect unforeseen objects. This means that sensor devices are needed to scan the space around the laser processing head in a non-contact and three-dimensional manner to detect any interfering components, such as protruding components, plates of different thicknesses, or contaminants.

[0004] DE2829851A1 describes a device for measuring the distance between a metal workpiece and a processing tool by a capacitive distance sensor, which can process workpieces with irregular surfaces and in particular with protruding parts extending parallel to the tool track.

[0005] DE102017201730A1 relates to a welding method and a welding arrangement, in which a time-of-flight (ToF) detection device is used to detect an observation window on the workpiece at least partially in front of the welding point.

[0006] DE102015015651B3 relates to a monitoring device for a laser processing system, which has a measurement beam source and an alignment unit for detecting a part of the measurement beam reflected by the surrounding environment. The measurement beam is coaxially coupled into the laser processing head with the processing beam, so that the measurement beam and the processing beam are aligned with a common position in the surrounding environment.

[0007] DE102012212278A1 relates to a device for manufacturing holes or weld seams, in which the distance between the workpiece and the device is detected by a coaxial autofocus device. The autofocus device may include an OCT device, a ToF camera, or a triangulation unit. Summary of the Invention

[0008] A task of the present invention is to provide a laser processing head that includes an efficient and multifunctional device for observing a process space, in particular for observing a three-dimensional process space.

[0009] Another object of the present invention is to provide a laser processing head including means for observing a processing space, which can reliably identify objects in the processing space even at high processing speeds or machining speeds.

[0010] Another object of the present invention is to provide a laser processing head including means for observing a processing space, which can perform planar or two-dimensional object recognition or planar or two-dimensional detection of obstacles in the processing space.

[0011] Another object of the present invention is to provide a laser processing head including means for observing a processing space, which can control or adjust a processing process by reliably identifying objects in the processing space, especially for monitoring a processing process and / or preventing collisions.

[0012] At least one of the above objects is solved by the subject matter of independent claim 1.

[0013] According to one aspect of the present disclosure, a laser processing head for processing a workpiece (especially a metal workpiece) using a laser beam includes: a housing in which optical elements for guiding and / or shaping the laser beam are arranged, such as a focusing optical device for focusing the laser beam; at least one lidar sensor for detecting the distance between the laser processing head and an object in a detection space or a processing space; wherein the lidar sensor is externally mounted on the housing, and the beam path of the lidar sensor extends outside the housing.

[0014] According to another aspect, a method for monitoring a laser processing process includes the following steps: performing a laser processing process by emitting a laser beam from a laser processing head (e.g., a laser processing head according to one of the embodiments described herein) to at least one workpiece (especially a metal workpiece), wherein the laser processing head and the workpiece move relative to each other along a processing path; detecting distance data during the laser processing process by at least one lidar sensor arranged on the laser processing head, the lidar sensor scanning a first detection space and a second detection space and detecting corresponding distance data, wherein the first detection space is farther from the laser processing head than the second detection space and the lidar sensor detects the distance data of the first detection space at a lower resolution (or with a coarser pixel grid and / or a lower scanning rate) than the distance data of the second detection space; and determining whether there are obstacles in the regions along the processing path in the first detection space and / or the second detection space according to the detected distance data. The first detection space may also be referred to as a far zone, and the second detection space may be referred to as a near zone. The lidar sensor may be externally mounted on the laser processing head or the housing of the laser processing head, and / or the beam path of the lidar sensor may extend outside the laser processing head or the housing of the laser processing head.

[0015] The laser processing head may include a control device configured to perform a method according to one of the embodiments of the present invention.

[0016] In the present disclosure, the process space refers to a space within which the laser processing head can move relative to the workpiece, particularly a space within which the laser processing head can move relative to the workpiece during the processing operation and / or along a processing path specified for the processing operation. In other words, the process space is defined relative to the workpiece, i.e., the workpiece is stationary within the process space. The detection space refers to the following region of the process space, which can be detected by a lidar sensor or in which the lidar sensor can detect an object. The detection space is a region of the process space, i.e., the detection space is located within the process space. The detection space can be defined by the mounting height of the lidar sensor on the laser processing head and / or the detection angle or opening angle of the lidar sensor. The TCP region refers to the following region of the process space in which the laser beam can be directed relative to the laser processing head. In a fixed optical device - laser processing head, this may be just the beam profile of the laser beam emerging from the laser processing head, i.e., a line including the TCP (tool center point, also known as the processing point) or the laser beam focus. In a scanner - laser processing head, this may be a conical space determined by the beam deflection characteristics of the scanning device.

[0017] The present disclosure relates to three-dimensional (3D) shaping for laser cutting and laser welding using at least one lidar sensor (light-detection and ranging, also known as lidar, laser-detection and ranging). The lidar sensor can in particular be a lidar camera. In particular, two subgroups can be used, namely an AMCW lidar sensor (amplitude-modulated continous wave, also known as indirect time-of-flight, iToF) and an FMCW lidar sensor (frequency-modulated continous wave). According to the invention, it is necessary to measure the space outside the direct processing area or the TCP area, for example, to detect objects in the surroundings of the laser processing head. Here, the object can be an obstacle located on or in the surrounding area of a predetermined laser processing path, i.e., an object that may collide with the laser processing head along the processing path due to the relative movement of the laser processing head and the workpiece. These obstacles can be protruding sheet metal parts, workpieces or sheets of different thicknesses, contaminants, clamping devices for clamping the workpiece, etc. However, the obstacle can also be a feature of the processed or unprocessed workpiece, such as a joint edge or seam between two workpieces (i.e., in the forward direction); a mark or positioning aid on a clamping or holding device for clamping the workpiece, or a mark or positioning aid on the workpiece, or the lateral profile of the workpiece, for the orientation or alignment of the laser processing head; the topography or surface curvature or inclination of the workpiece; or a weld seam or cutting edge produced by laser processing (i.e., in the backward direction).

[0018] Due to the diversity of lidar sensors, the laser processing head of the present invention only needs to be installed once to provide very wide possibilities for process space observation. In particular, object recognition can thus be carried out in areas available for process adjustment and / or for collision avoidance adjustment.

[0019] The laser processing head or method according to one of the above aspects can include one or more of the following features:

[0020] The laser processing head can be a laser processing head for performing a processing process, in particular for laser cutting, laser separation, laser fusion welding, laser brazing, laser drilling, etc. on a workpiece using a laser beam. The workpiece can in particular be a metal workpiece.

[0021] The lidar sensor can preferably be removably or reversibly externally mounted on the housing (i.e., outside the optical space defined in the housing). The lidar sensor can include a lidar camera and / or be configured to detect distances in a spatially resolved manner. In other words, the lidar sensor can be configured to detect objects in a three-dimensional detection space. The lidar sensor can be a ToF-based sensor. The lidar sensor can be an FMCW lidar sensor or an AMCW lidar sensor, i.e., the radiation can be periodically modulated in amplitude or frequency. These two technologies are suitable for spatial resolution in the sub-millimeter range.

[0022] The lidar sensor can include at least one detector and at least one emitter. The detector and the emitter can be spatially adjacent to each other or spatially separated from each other. When the detector and the emitter are spatially separated, the emitter can illuminate the detection spaces of different detectors. In other words, multiple detectors can share one emitter.

[0023] The lidar sensor or the detector can include at least one photodiode, a diode array, a CMOS sensor, at least one avalanche photodiode, etc. The lidar sensor or the emitter can include a beam source, in particular a laser beam source, a beam source array, a laser beam source array, at least one LED, an LED array, at least one VCSEL, a VCSEL array, etc. The emitter or the beam source can be a laser beam source or a beam source array in the visible light range, the near-infrared range, or the infrared frequency range.

[0024] The lidar sensor can further include beam shaping optics, such as a diffuser, a diffraction element, a wide-angle lens, or a modulation optical device.

[0025] The lidar sensor can further include a protective glass and / or a cross-jet device for generating an air curtain to prevent contamination caused by, for example, smoke or splashing.

[0026] The detection space of the lidar sensor can be at least partially located outside the TCP region and / or include a region of the workpiece surface. In particular, the TCP can be located outside the detection space of the lidar sensor. The detection space of the lidar sensor can also be completely located outside the TCP region, i.e., not include the TCP region. The detection space of the lidar sensor can be at least partially or only partially limited by the workpiece surface. The detection space of the lidar sensor can be limited by the detection angle of the lidar sensor and at least partially limited by the workpiece or the workpiece surface. The detection space of the lidar sensor can be (at least partially) arranged in front of and / or behind the laser processing head and / or on the side of the laser processing head. The area to be processed of the workpiece is located in front of the laser processing head, and the processed area of the workpiece is located behind.

[0027] The lidar sensor can be arranged on the housing such that the optical axis of the lidar sensor and / or the central axis of its detection space forms an angle greater than 0° and / or less than 90°, especially greater than 20°, 30° or 45°, with the optical axis of the focusing optical device or with the vertical axis.

[0028] The lidar sensor can be pivotably and / or movably arranged on the housing so that the position of the detection space and / or the optical axis of the lidar sensor is adjustable. The lidar sensor, especially the transmitter and / or detector of the lidar sensor, can pivot about an axis perpendicular to the optical axis of the focusing optical device and / or a horizontal axis and / or an axis parallel to the side surface of the housing. In other words, the radiation angle and / or the detection angle of the lidar sensor are adjustable. The lidar sensor, especially the transmitter and / or detector of the lidar sensor, can move on the housing parallel to the optical axis of the focusing optical device and / or along the vertical axis. In other words, the mounting height of the lidar sensor is adjustable. The mounting height as well as the radiation angle or the detection angle are crucial for the size of the detection space, especially the size of the measurement area.

[0029] The housing can include guiding means, such as tracks, along which the lidar sensor can move. The edges (such as the lower edge) and / or corners (such as the lower corners) of the housing can have chamfers or inclined surfaces where the lidar sensor is arranged or on which it is arranged.

[0030] The lidar sensor can include a bracket. The lidar sensor, i.e., the transmitter and / or detector of the lidar sensor, can be received on the bracket. The bracket can be pivotably and / or movably and / or detachably and / or rotatably arranged on the housing. Alternatively or additionally, the transmitter and / or detector can also be pivotably and / or movably arranged on the bracket. The lidar sensor can be motorized and / or automated to pivot about an axis perpendicular to the optical axis of the focusing optical device and / or around a horizontal axis.

[0031] The control device (such as the lidar control device or the control device of the laser processing head) can be configured to control the lidar sensor such that the lidar sensor pivots back and forth between two positions. In this way, the lidar sensor can, for example, have a first detection space in the far zone and a second detection space in the near zone. The control device can also be configured to adapt the (lateral and / or axial) resolution of the lidar sensor to the respective detection space. For example, the control device can be configured to make the (lateral and / or axial) resolution of the lidar sensor in the first detection space lower than that in the second detection space.

[0032] The lidar sensor can be configured to detect its detection space at different (lateral and / or axial) resolutions. In other words, the (lateral and / or axial) resolution of the lidar sensor is adjustable. A control device, such as a lidar control device or a control device of a laser processing head, can be configured to adjust the (lateral and / or axial) resolution of the lidar sensor.

[0033] The laser processing head can include a module that contains at least one lidar sensor and is detachably fixed to the housing. The module can be fixed coaxially to the housing. The module can have an opening for the laser beam path, i.e., allowing the laser beam to pass through its center. The module can be arranged between the housing and the nozzle or on the underside of the housing. The module can include a plurality, especially at least four, lidar sensors arranged around the optical axis of the focusing optics. The module can be rotatably fixed to the housing in a motorized or manual manner. By means of such a rotatable sensing device, blind spots or dead zones around the laser processing head can be reduced, i.e., areas that cannot be detected by any lidar sensor. This means that a 360-degree view can be achieved. The module can include an interface for transmitting data from the lidar sensor to the control device of the laser processing head (wirelessly or wired). The module can include an electronic construction and / or a module control device and / or a lidar control device for controlling the at least one lidar sensor and, if necessary, other components of the module. The module can include a gas connection for a cross-jet device. The module can include a chamfered lower edge or an inclined lower edge and / or an inclined corner, and at least one of the lidar sensors is arranged on the chamfered lower edge or the inclined lower edge and / or the inclined corner.

[0034] The laser processing head can include a lidar control device for controlling the at least one lidar sensor and / or for evaluating data from the at least one lidar sensor. The lidar control device can be configured to generate a distance signal based on the detection data of the at least one lidar sensor. The lidar control device can be connected (wired or wirelessly) to the control device of the laser processing head for one-way or two-way data exchange and can also be integrated into the laser processing head.

[0035] The laser processing head may include a plurality of lidar sensors. When the detection spaces of the lidar sensors overlap, these lidar sensors with overlapping detection spaces may be sensitive to different wavelengths (wavelength ranges). For example, filters for different wavelengths (wavelength ranges) may be arranged in front of the detectors of the lidar sensors with overlapping detection spaces, and / or the transmitters of the lidar sensors with overlapping detection spaces can emit at different wavelengths (wavelength ranges). The lidar sensors with overlapping detection spaces can also be alternately controlled, for example, by a common lidar control device of the lidar sensors, which can also be the control device of the laser processing head or can be integrated into the laser processing head. In other words, these lidar sensors can be controlled so that their detection periods and / or emission or illumination periods do not overlap.

[0036] The at least one lidar sensor may include a first lidar sensor having a first detection space and a second lidar sensor having a second detection space. The second detection space (near zone) can be closer to the laser processing head than the first detection space (far zone). The optical axis of the first lidar sensor can form a larger angle with the optical axis of the focusing optical device than the optical axis of the second lidar sensor. The optical axis of the first lidar sensor can form an angle between 70° and 110°, especially about 90°, with the optical axis of the focusing optical device. The optical axis of the second lidar sensor can form an angle of 10° to 50°, especially 30° to 40°, with the optical axis of the focusing optical device. The first detection space can be smaller than the second detection space.

[0037] The first sensor may be configured to detect distances within its detection space with a lower (lateral and / or axial) resolution than the second sensor. Alternatively, the control device may be configured to control the first and second sensors such that the first sensor detects distances with a lower (lateral and / or axial) resolution than the second sensor. In other words, when measuring the area close to the laser processing head, the (axial and / or lateral) resolution should be higher than when measuring the distant area. For example, no obstacles should be ignored in the near zone, while in the distance, the response time is longer, so less accuracy is required.

[0038] Therefore, it is advantageous to use different measurement grids to measure obstacles. Obstacles closer to the laser processing head should be scanned with a higher resolution than obstacles farther away. But at the same time, the scanning space for obstacles closer should not have to be as large as that for obstacles farther away.

[0039] The laser processing head may include a third lidar sensor having a third detection space and / or a fourth lidar sensor having a fourth detection space, wherein the third lidar sensor is arranged on the front side of the laser processing head, i.e., along the movement direction of the laser processing head in the process space, and wherein the fourth lidar sensor is arranged on the rear side of the laser processing head. Accordingly, the third detection space may be located in front of the laser processing head, and / or the fourth detection space may be located behind the laser processing head. The fourth lidar sensor may be configured to detect an object with a lower (lateral and / or axial) resolution than at least one of the first, second, and third lidar sensors.

[0040] Therefore, measurement grids with different lateral and axial resolutions and imaging space ranges can be used for three-dimensional imaging. Thus, when scanning deep spaces or far zones (relative to TCP > 50 cm and < 500 cm) or rear detection spaces, a coarser and wider grid can be used than when scanning near spaces or near zones (relative to TCP > 20 cm and < 50 cm) or front detection spaces.

[0041] The laser processing head may include a control device for controlling and / or regulating the processing process, e.g., controlling and / or regulating based on the distance data detected by the at least one lidar sensor. The control device may include a lidar control device for controlling the at least one lidar sensor and / or for evaluating the data or distances detected by the lidar sensor. The control device may be configured to classify an object as critical or non-critical based on the data or distances detected by the lidar sensor. The critical or non-critical classification of the object may be performed according to process parameters, such as the feed rate or speed of the laser processing head in the process space, the system inertia (mechanical and / or sensor), the response time, the predefined processing path, etc. Here, non-critical means that the laser processing head will not collide with an object when moving along the specified processing path, regardless of whether the collision is due to the position or size of the object. Accordingly, critical means that the laser processing head will collide with an object.

[0042] The control device may be configured to perform measures to prevent collisions. The measure may be selected from at least one of the following measures according to the distance of the object classified as critical from the laser processing head: bypassing the object, stopping the processing process, shutting off the laser beam, slowing down or stopping the relative movement between the laser processing head and the workpiece.

[0043] The requirement for resolution may be related to the response space of the laser processing head. This response space is defined by the response time, i.e., the time required for the laser processing head or the laser processing system to respond to an obstacle. Here, the response or measure may vary, ranging from bypassing, decelerating to an emergency stop of the machine. In addition, the response also includes that the laser beam may be shut off or blocked.

[0044] This unit can also be used to measure the distance from the cutting nozzle to the upper or side profile of the sheet. Therefore, the capacitive distance sensor device can be calibrated in absolute units and even replaced. Description of the Drawings

[0045] The drawings show embodiments of the present disclosure, which will be described in more detail below. In the drawings:

[0046] Figure 1 A schematic diagram of a laser processing head is shown, which includes a lidar sensor and a second lidar sensor, each lidar sensor being arranged outside the laser processing head;

[0047] Figure 2 Another schematic diagram of a laser processing head is shown, which includes a lidar sensor, a second lidar sensor, and a third lidar sensor, each lidar sensor being arranged outside the laser processing head;

[0048] Figures 3A to 3D The various arrangements of the lidar sensor on the laser processing head are shown.

[0049] Figures 4A to 4C The various arrangements of multiple lidar sensors on the laser processing head are shown.

[0050] Figure 5A and 5B A module that can be fixed to the laser processing head is shown, in which at least one lidar sensor is arranged. Detailed Description of the Invention

[0051] In the following, unless otherwise specified, the same reference numerals are used for the same or functionally identical elements.

[0052] Figure 1 A laser processing head 1 is shown, which includes a housing 2, focusing optics 9, and a nozzle 8. The focusing optics 9 includes a lens or a lens group for focusing the laser beam 3. The laser beam exits from the opening of the nozzle 8 and hits the processing area or TCP 5 on the workpiece. The processing area 5 can be a cut 6 in the workpiece 4 or a weld 6 between two workpieces 4. In addition, a control device can be integrated into the laser processing head 1 or connected to the laser processing head 1 by wire or wirelessly. The control device 100 is used to control the laser processing head 1 and its components or to control the execution of the laser processing process. The control device 100 can also control the lidar sensor 11 and / or evaluate the data detected by the lidar sensor.

[0053] On the outer side of the housing 2, for example, on the front side in the processing direction, a (first) lidar sensor 11 is arranged. The lidar sensor 11 can detect objects in the first detection space 111 or determine the distance to the objects in the detection space 111. The lidar sensor 11 can generate a first scan grid 112 with a predetermined first resolution. The lidar sensor 11 is configured to detect objects in front, that is, objects arranged in front of the laser processing head relative to the processing direction. The detection space 111 of the first lidar sensor 11 preferably points to the space, but may also be partially limited by the workpiece 4.

[0054] A second lidar sensor 12 can be arranged on the lower edge of the housing 2. The second lidar sensor 12 can detect objects in the second detection space 121 or determine the distance to the objects in the detection space 121, and this detection space is closer to the laser processing head (near zone). The lidar sensor 12 can generate a second scan grid 122 with a predetermined second resolution. The second resolution can be higher than the first resolution, or the second scan grid 122 can be finer than the first scan grid 112. The resolution of the lidar sensor 11 or 12 can also be correspondingly set by the control device 100.

[0055] Compared with the central axis of the second detection space 121, the central axis of the first detection space 111 (i.e., the central axis passing through the first lidar sensor) forms a larger angle with the optical axis of the focusing optical device 9. In other words, the second lidar sensor 12 is more oriented towards the workpiece or more downward than the first lidar sensor 11. The second detection space 121 can be smaller than the first detection space 111. The second detection space 121 and the first detection space 111 can be separated from each other (as Figure 1 shown) or overlapped (as Figure 2 shown).

[0056] The first lidar sensor 11 and the second lidar sensor 12 can be arranged on the same side of the housing 2, for example, as shown in the figure, arranged on the front side or facing forward. However, these sensors can also be arranged on different sides of the housing 2. In addition, other lidar sensors can also be arranged on this or these outer sides of the housing 2. In Figure 1 and Figure 2 the example shown, both detection spaces 111 and 121 are oriented towards the forward direction, that is, forward along the processing direction. However, the present disclosure is not limited to this. For example, the two detection spaces 111 and 121 can also be oriented in different directions, such as upstream and downstream.

[0057] Figure 2Shows another embodiment of the laser processing head 1, which includes a third lidar sensor 13 disposed on the outer side of the housing 2, between the second lidar sensor 12 and the first lidar sensor 11. The third lidar sensor 13 has a third detection space 131 and generates a third scanning grid 132. The first scanning grid 111, the second scanning grid 122, and the third scanning grid 132 may overlap and have different sizes or grids of different sizes.

[0058] Figures 3A to 3D Shows various arrangements of lidar sensors on the laser processing head 1. One or more lidar sensors can be arranged on the laser processing head 1 in one or more of the arrangements shown in Figures 3A to 3D One or more lidar sensors can be arranged on the laser processing head 1 in one or more of the arrangements shown in Figure 1 Or Figure 2 The first, second, and / or third lidar sensors in Figures 3A to 3D Can be arranged on the laser processing head in one or more different arrangements shown in Figures 3A to 3D For clarity, the lidar sensor is denoted by 11 in

[0059] As described above, the lidar sensor 11 has a detection space 111. The detection space 121 is determined by the opening angle or detection angle 113 of the lidar sensor 11 and the position of the lidar sensor on the laser processing head 1 or the housing 2. The angular bisector of the detection angle 113 constitutes the central axis 114 of the detection space 111. The central axis 114 of the detection space 111 may correspond to the optical axis of the lidar sensor 11.

[0060] Figure 3A Shows the housing 2 of the laser processing head 1, which has a chamfer at the lower edge, that is, an inclined edge. The chamfer can be formed at the lower edge and / or the lower corner of the housing 2. The lidar sensor 11 is arranged at or on the chamfer. In this way, the orientation of the lidar sensor 11 is obliquely downward, that is, obliquely facing the workpiece. The detection space 111 is at least partially limited by the workpiece surface (and the detection angle 113). The housing 2 may have a rectangular cross-section and have chamfers at least at two lower edges, and at least one lidar sensor is arranged at each chamfer. The housing 2 may have a circular cross-section, and the circumferential lower edge may be configured as a chamfer, and at least one lidar sensor is arranged on the chamfer.

[0061] Figure 3BThe housing 2 of the laser processing head 1 is shown, and a bracket 1111 with a lidar sensor 11 is rotatably or pivotably arranged on the outer side of the housing. The bracket 1111 with the lidar sensor 11 can rotate relative to the housing 2 about a rotation axis 1113, and the rotation axis extends horizontally and / or parallel to the outer side. The bracket 1111 with the lidar sensor 11 can rotate automatically, mechanically or manually. Therefore, the orientation of the lidar sensor 11 or the detection space 111 of the lidar sensor 11 is adjustable. In particular, the angle between the optical axis of the focusing optical device 9 or the workpiece surface and the central axis 114 of the detection space 111 is adjustable. In addition, the bracket 1111 can additionally have a chamfer at the lower outer edge, and the lidar sensor 11 can be arranged on the chamfer. The bracket 1111 can be mounted on the housing 2 through a housing bracket 1112. The bracket 1111 is rotatably mounted on the housing bracket 1112.

[0062] Figure 3C The housing 2 of the laser processing head 1 is shown, and a track 1114 is arranged or integrated on the outer side of the housing. A bracket 1111 with a lidar sensor 11 is arranged on the track 1114. The bracket 1111 can move on the track 1114 in a vertical and / or horizontal displacement direction 1115. The bracket 1111 with the lidar sensor 11 can move automatically, mechanically or manually. Therefore, the mounting height or position of the lidar sensor 11 or the detection space 111 of the lidar sensor 11 is adjustable. In addition, the bracket 1111 can have a chamfer at the lower outer edge, and the lidar sensor 11 can be arranged on the chamfer.

[0063] Figure 3D The arrangement of the lidar sensor on the housing 2 of the laser processing head 1 is shown, in which the Figure 3B and Figure 3C arrangements are combined. The bracket 1111 with the lidar sensor 11 can move on the outer side of the housing along the track 1114 and can additionally rotate relative to the housing 2 or the laser processing head about a rotation axis 1113.

[0064] Figures 4A to 4C The arrangement of four lidar sensors 11 on the laser processing head 1 and their detection spaces 111 are shown. However, the number of sensors provided on the laser processing head can also be less than or more than four. The arrangement on the laser processing head can be carried out as Figures 3A to 3C shown. Figures 4A to 4C The laser processing head 1 is shown from below.

[0065] In Figure 4A , four lidar sensors 11 are respectively arranged on the outer side of the housing 2. In Figure 4BIn [description], four lidar sensors 11 are mounted on the chamfered lower edge of the housing. The central axes of the detection spaces of adjacent lidar sensors are at 90° angles to each other. With this arrangement, objects or obstacles in the process space can be recognized from all directions. The detection spaces 111 of the lidar sensors 11 may overlap, but this is not necessary.

[0066] In Figure 4C In addition to the four lidar sensors 11 arranged as shown in Figure 4A or 4B, additional lidar sensors 11 are provided at each corner of the housing 2 of the laser processing head 1. The central axes of the detection spaces of adjacent lidar sensors are at 45° angles to each other. This enables panoramic viewing.

[0067] Figures 4A to 4C The lidar sensors 11 shown can also be arranged in a module 20. This module can be reversibly fastened to the housing 2, for example, arranged between the housing 2 or the focusing optical device 9 and the nozzle 8.

[0068] Figure 5A and 5B show embodiments of the module 20 that can be arranged between the housing 2 and the nozzle 8 and include at least one lidar sensor 11. Preferably, at least one lidar sensor 11 is arranged on each side of the module 20, as shown in Figures 4A to 4C shown.

[0069] Figure 5A shows an embodiment of the module 20 in which the lidar sensors 11 are arranged at the chamfered corners. The lidar sensors 11 are protected by a protective glass 10 from contamination. In addition, at least one cross-jet device with at least one vent 22 can be arranged beside the lidar sensors 11 to protect the lidar sensors or the protective glass from smoke and other contaminants through an air curtain. The cross-jet device is configured to supply gas (such as compressed air) through the vent 22 to the lidar sensors 11 in a manner similar to an air curtain through the joint 23 of the module.

[0070] Figure 5B shows an embodiment of the module 20 in which two lidar sensors 11 are arranged on one side of the module 20. Of course, only one lidar sensor 11 can also be arranged on one side. The module can have a chamfered lower edge on which the lidar sensors 11 are arranged. The lidar sensors 11 can be arranged as shown in Figures 4A to 4C shown. The lidar sensors 11 can be protected from contamination by the protective glass 10 and / or the cross-jet device.

[0071] The laser processing head includes a control device 100 for controlling and / or adjusting the processing process based on the distance data detected by the at least one lidar sensor 11, 12, 13. The control device may include a lidar control device for controlling the at least one lidar sensor and / or for evaluating the data or distances detected by the lidar sensor or for communicating with such a system in a wired or wireless manner. The control device 100 may be configured to perform anti-collision measures. The control device 100 may be configured to classify an object as critical or non-critical based on the data or distances detected by the lidar sensor to prevent collisions. The critical or non-critical classification of the object may be based on process parameters, for example, the feed rate or speed of the laser processing head in the process space, the system inertia (mechanical and / or sensor), the response time, the predetermined processing path, etc. Here, non-critical means that the laser processing head will not collide with an object when moving along the predetermined processing path - whether due to the position or size of the object. Correspondingly, critical means that the laser processing head will collide with an object. A critical object may be regarded as an obstacle.

[0072] The control device 100 may be configured to perform a method for monitoring a laser processing process, the method including the steps of: irradiating a laser beam 3 onto a workpiece 4 through a laser processing head 1 to perform a laser processing process, wherein the laser processing head and the workpiece move relative to each other along a processing path; detecting distance data during the laser processing process by at least one lidar sensor 11, 12, 13 arranged on the laser processing head 1; and determining whether there is an obstacle or a critical object in the area along the processing path based on the detected distance data. The control device 100 of the laser processing head 1 may be configured to perform this method.

[0073] In the step of detecting the distance data, the lidar sensor may scan a first detection space and a second detection space and detect the corresponding distance data, wherein the first detection space is farther from the laser processing head than the second detection space. The first detection space may also be referred to as the far zone, and the second detection space may be referred to as the near zone. The lidar sensor may be movably (e.g., rotatably) arranged on the laser processing head to scan two different detection spaces. The resolution of the lidar sensor is adjustable such that the resolution of the lidar sensor when scanning the first detection space (far zone) is lower than the resolution when scanning the second detection area (near zone). Additionally, two lidar sensors may be provided, one for scanning the first detection space and the other for scanning the second detection space. The resolution of the first lidar sensor scanning the first detection space may be lower than the resolution of the second lidar sensor scanning the second detection space. This detection space of the lidar sensor or these detection spaces of the lidar sensor are preferably oriented towards the forward direction.

[0074] When scanning two different detection spaces, the method may further include: determining, based on the detected distance data, whether there is an obstacle in the first detection space in the area along the machining path, and / or whether there is an obstacle in the second detection space in the area along the machining path.

[0075] The method may further include: selecting an anti-collision measure based on the distance between the obstacle and the laser processing head and on whether there is an obstacle in the first or second detection space. Examples of anti-collision measures include: bypassing the obstacle, stopping the machining process, shutting off the laser beam, and slowing down or stopping the relative movement between the laser processing head and the workpiece.

[0076] Using at least one lidar sensor, the beam curve or beam path of which extends outside the laser processing head and / or the optical axis of which or the central axis of the detection space forms an angle with the optical axis of the focusing optical device (and / or with the vertical direction), so as to achieve economical, flexible, and multi-functional process monitoring of the machining process.

[0077] List of reference numerals

[0078] 1 Laser processing head

[0079] 2 Housing

[0080] 3 Laser beam

[0081] 4 Workpiece

[0082] 5 Machining area (TCP)

[0083] 6 Cutting seam and / or weld

[0084] 7 Chamfer

[0085] 8 Nozzle

[0086] 9 Focusing optical device

[0087] 11 (First) lidar sensor

[0088] 111 Detection space

[0089] 112 Scanning grid

[0090] 113 Detection angle

[0091] 114 Central axis of the detection space

[0092] 1111 Bracket

[0093] 1112 Housing bracket

[0094] 1113 Rotation axis

[0095] 1114 Track

[0096] 1115 Displacement direction

[0097] 12 Second lidar sensor

[0098] 121 Second detection space

[0099] 122 Second scanning grid

[0100] 13 Third lidar sensor

[0101] 131 Detection space of the third lidar sensor

[0102] 132 Scanning grid of the third lidar sensor

[0103] 20 Module

[0104] 21 Protective glass

[0105] 22 Cross jet or vent

[0106] 23 Gas connector

[0107] 24 Sensor side

[0108] 100 Control device.

Claims

1. A laser processing head (1) for processing a workpiece (4) using a laser beam, comprising: a housing (2) in which a focusing optical device (9) for focusing the laser beam (3) is arranged; and at least one lidar sensor (11, 12, 13) for detecting the distance between the laser processing head (1) and an object in the process space; wherein the lidar sensor (11, 12, 13) is arranged externally on the housing (2), and the beam path of the lidar sensor (11, 12, 13) extends outside the housing (2).

2. The laser processing head (1) according to claim 1, wherein, The lidar sensor (11, 12, 13) is arranged on the housing (2) such that the detection space (111, 121, 131) of the lidar sensor (11, 12, 13) is at least partially located outside the TCP region and / or includes the region of the workpiece surface.

3. The laser processing head (1) according to one of the preceding claims, wherein, The optical axis of the lidar sensor (11) and / or the central axis (114) of the detection space form an angle greater than 0° and / or less than 90° with the optical axis of the focusing optical device.

4. The laser processing head (1) according to one of the preceding claims, wherein, The lidar sensor (11) is pivotably and / or movably arranged on the housing (2) such that the position of the detection space (111) and / or the central axis (114) of the detection space and / or the optical axis of the lidar sensor (1) is adjustable.

5. The laser processing head (1) according to one of the preceding claims, wherein, The housing (2) includes a track (1114) along which the lidar sensor (11) can move, and / or the housing (2) includes a lower edge with a chamfer, and the lidar sensor (11) is arranged on the chamfer.

6. The laser processing head (1) according to one of the preceding claims, wherein, The laser processing head (1) includes a module (20) that contains the at least one lidar sensor (11) and is arranged between the housing (2) and the nozzle (8) of the laser processing head (1).

7. The laser processing head (1) according to one of the preceding claims, wherein, The lidar sensor (11) includes a protective glass (10) and / or a cross-jet device for preventing contamination.

8. The laser processing head (1) according to one of the preceding claims, wherein, The lidar sensor (11, 12, 13) includes a ToF-based sensor, an AMCW sensor, or an FMCW sensor; and / or, the lidar sensor (11, 12, 13) is configured to detect distance in a spatially resolved manner; and / or, the lidar sensor (11, 12, 13) is a lidar camera.

9. The laser processing head (1) according to one of the preceding claims, wherein, The at least one lidar sensor includes a first lidar sensor (11) having a first detection space (111) and a second lidar sensor (12) having a second detection space (121), wherein the angle between the central axis (114) of the detection space of the first lidar sensor (11) and the optical axis of the focusing optical device (9) is greater than the angle between the central axis of the detection space of the second lidar sensor (12) and the optical axis of the focusing optical device (9).

10. The laser processing head (1) according to claim 9, wherein, The first lidar sensor (11) is configured to detect distance at a lower resolution than the second lidar sensor (12).

11. The laser processing head (1) according to one of the preceding claims, wherein, The laser processing head (1) includes a plurality of lidar sensors (11, 12, 13), and the lidar sensors (11, 12, 13) are arranged on opposite sides of the housing (2) and / or on the housing (2) around the optical axis of the focusing optical device (9).

12. The laser processing head (1) according to one of the preceding claims, wherein, The laser processing head (1) includes control means for controlling and / or adjusting the processing technology according to the distance data detected by the at least one lidar sensor (11, 12, 13) and / or for controlling the at least one lidar sensor (11, 12,13) and / or for evaluating the distance detected by the at least one lidar sensor (11, 12, 13).

13. The laser processing head (1) according to claim 12, wherein, The control means is configured to classify an object as critical or non-critical according to the distance detected by the lidar sensors (12, 13, 14) to prevent a collision.

14. The laser processing head (1) according to claim 13, wherein, The control means is configured to perform measures for preventing a collision with an object classified as critical and to select measures from at least one of the following according to the detected distance: bypassing the object, stopping the processing technology, shutting off the laser beam (3), and slowing down or stopping the relative movement between the laser processing head (1) and the workpiece (4).

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