Laser processing system and control method

Abstract

A laser processing system capable of easily performing correction of a control point is provided. The laser processing system includes a scanner capable of scanning a workpiece with a laser beam; a moving device that moves the scanner relative to the workpiece; and a scanner control device that controls the scanner; wherein the scanner control device has a trajectory control section that controls the scanner so that, in a state in which the moving device has stopped, the scanner irradiates the workpiece with a control point correction trajectory for correcting a control point that is set in advance, the control point correction trajectory having a prescribed length for determining a deviation in an optical axis direction of the laser beam and a prescribed shape for determining a position of the control point and a direction of a coordinate system defined by the control point.

Description

Technical Field

[0001] This invention relates to a laser processing system and control method. Background Technology

[0002] Laser processing systems have been proposed for welding by irradiating a workpiece with a laser beam from a distant position. These systems typically have a scanner at the end of a robot arm for irradiating the laser beam. The robot axes of these systems are driven according to pre-stored programs in a control unit, similar to other industrial robots. Therefore, a teaching operation is performed at the work site using the actual machine and workpiece to create the program (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-135781 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] When using such a laser processing system for laser processing, the offset between the path of the laser irradiation point in the program and the actual path of the laser irradiation point becomes a problem.

[0008] The path of the laser illumination point can be represented by a series of points in a coordinate system with the robot's base within the workspace as the reference point; these points are therefore called control points. Control points can be points on the path of the laser illumination point, or they can be points not on the path of the laser illumination point, such as the center of an arc, but necessary for defining the path of the laser illumination point.

[0009] The robot program and scanner program are generated based on the positions and orientations (coordinate system of the control points) of each control point set in the program generation device of the laser processing system. However, the CAD data is inconsistent with the actual workpiece, and there are also positional errors in the robot's motion path, fixtures, etc. Therefore, it is necessary to perform teaching correction operations to address such offsets and errors.

[0010] Additionally, when combining a robot with a scanner in a laser processing system, it is sometimes necessary to correct the tool center point (TCP). The TCP is represented by a position vector from the robot's front end towards the scanner's reference point. By correctly setting the TCP, the programmed laser irradiation position will match the actual laser irradiation position regardless of the robot's posture.

[0011] Previously, a teaching jig was used to correct the control point and set the TCP (Control Point) by pointing to a specific point directly below the scanner. Typically, the specific point was the origin of the scanner's workspace, set as the point where the laser converged.

[0012] To indicate a specific point, a teaching jig made of metal, resin, or similar material is used, or multiple additional guide lasers are intersected to visually identify their intersection. However, both methods are inefficient because obtaining the coordinates of a point directly below the scanner requires maneuvering the robot to align the desired position on the actual workpiece with that point.

[0013] Furthermore, conventional methods require mounting a teaching jig on the robot or equipping the scanner with an additional guiding laser. Therefore, a laser processing system that can easily correct control points without requiring a teaching jig or additional guiding laser is desired.

[0014] Solution for solving the problem

[0015] The laser processing system disclosed herein includes: a scanner capable of scanning a workpiece with a laser beam; a moving device for moving the scanner relative to the workpiece; and a scanner control device for controlling the scanner, wherein the scanner control device has a trajectory control unit that controls the scanner such that, when the moving device is stopped, the scanner illuminates the workpiece with a control point correction trajectory for correcting a pre-set control point, the control point correction trajectory having a predetermined length for determining the deviation in the optical axis direction of the laser beam, and a predetermined shape for determining the position of the control point and the direction of the coordinate system defined by the control point.

[0016] The control method for the laser processing system disclosed herein includes the following steps: moving a scanner capable of scanning a workpiece with a laser beam relative to the workpiece; stopping a moving device used to move the scanner relative to the workpiece; and controlling the scanner such that, in the state where the moving device is stopped, the scanner illuminates the workpiece with a control point correction trajectory for correcting a pre-set control point, wherein the control point correction trajectory has a predetermined length for determining the optical axis direction of the laser beam, and a predetermined shape for determining the position of the control point and the direction of the coordinate system defined by the control point.

[0017] The effects of the invention

[0018] According to the present invention, control points can be easily corrected. Attached Figure Description

[0019] Figure 1This is a diagram showing the overall structure of the laser processing system according to this embodiment.

[0020] Figure 2 This is a diagram illustrating the optical system of the scanner in the laser processing system according to this embodiment.

[0021] Figure 3 This is a block diagram illustrating the functional structure of the laser processing system according to this embodiment.

[0022] Figure 4A This shows the robot's path before the control points were corrected.

[0023] Figure 4B This shows the robot's path after the control points have been corrected.

[0024] Figure 5 This is a block diagram illustrating the functional structure of the scanner control device according to this embodiment.

[0025] Figure 6A This is a diagram showing an example of a trajectory used for control point correction.

[0026] Figure 6B It shows the use Figure 6A The diagram shows the action of correcting control points using a trajectory.

[0027] Figure 6C It is a diagram used to illustrate the deviation in the optical axis direction of a laser beam.

[0028] Figure 6D This is a diagram showing another example of a trajectory used for control point correction.

[0029] Figure 6E This is a diagram showing an example of a correction pattern used to correct the trajectory for control point correction.

[0030] Figure 6F This is a diagram illustrating the action of correcting control points using the trajectory with control point correction.

[0031] Figure 7A This is a diagram showing components welded using a laser processing system.

[0032] Figure 7B It is a diagram showing the trajectory for control point correction and the welded portion welded by a laser processing system.

[0033] Figure 8A A top view of a component welded using a laser processing system is shown.

[0034] Figure 8B A perspective view of a component welded using a laser processing system is shown.

[0035] Figure 8C This is a diagram showing the trajectory used for control point correction.

[0036] Figure 8D This is a diagram showing laser beams L irradiated from different positions.

[0037] Figure 9 This is a flowchart illustrating the processing flow of the laser processing system involved in this embodiment. Detailed Implementation

[0038] The embodiments of the present invention will now be described with reference to the accompanying drawings. Figure 1 This is a diagram showing the overall structure of the laser processing system 1 according to this embodiment. Figure 1 The laser processing system 1 shown represents an example of a remote laser welding robot system.

[0039] The laser processing system 1 includes a robot 2, a laser oscillator 3, a scanner 4, a robot control device 5, a scanner control device 6, a laser control device 7, a robot teaching operation board 8, and a program generation device 9.

[0040] Robot 2 is, for example, a multi-joint robot with multiple joints. Robot 2 has a base 21, an arm 22, and multiple joint axes 23a to 23d having a rotation axis extending along the Y direction.

[0041] In addition, robot 2 has multiple robot servo motors, such as a robot servo motor that rotates arm 22 about the Z-axis and a robot servo motor that rotates each joint axis 23a to 23d to move arm 22 in the X-axis. Each robot servo motor performs rotational drive based on drive data from robot control device 5, which will be described later.

[0042] The scanner 4 is fixed to the front end 22a of the arm 22 of the robot 2. Therefore, the robot 2 can move the scanner 4 to any position in the workspace at a predetermined robot speed and in any orientation by being driven by the rotation of each robot servo motor. That is, the robot 2 is a moving device for moving the scanner 4 relative to the workpiece 10. Furthermore, in this embodiment, the laser processing system 1 uses the robot 2 as a moving device, but it is not limited to this; for example, a three-dimensional machining machine can also be used as a moving device.

[0043] The laser oscillator 3 is composed of a laser medium, an optical resonator, and an excitation source. The laser oscillator 3 generates a laser beam as the laser output based on a laser output command from the laser control device 7 (described later), and supplies the generated laser beam to the scanner 4. Types of lasers used for oscillation include fiber lasers, CO2 lasers, and YAG lasers, but in this embodiment, the type of laser is not particularly limited.

[0044] The laser oscillator 3 is capable of outputting a processing laser for machining the workpiece 10 and a guide laser for adjusting the processing laser. The guide laser is a visible light laser that is adjusted on the same axis as the processing laser.

[0045] The scanner 4 is a device that can receive the laser beam L emitted from the laser oscillator 3 and scan the workpiece 10 with the laser beam L.

[0046] Figure 2 This is a diagram illustrating the optical system of the scanner 4 in the laser processing system 1 according to this embodiment. (See diagram for example.) Figure 2 As shown, the scanner 4 includes, for example, two detector mirrors 41 and 42 for reflecting the laser beam L emitted from the laser oscillator 3, a detector motor 41a for rotating the detector mirror 41, a detector motor 42a for rotating the detector mirror 42, and a protective glass 43.

[0047] Electron detector 41 is configured to rotate about rotation axis J1, and electron detector 42 is configured to rotate about rotation axis J2. These two rotation axes J1 and J2 are orthogonal to each other. Electron detector motors 41a and 42a drive the rotation based on drive data from laser control device 7, so that electron detector 41 rotates about rotation axis J1 and electron detector 42 rotates about rotation axis J2 independently.

[0048] The laser beam L emitted from the laser oscillator 3 is reflected sequentially by two detector mirrors 41 and 42 before being emitted from the scanner 4 and reaching the processing point (welding point) of the workpiece 10. At this time, when the detector motors 41a and 42a rotate the two detector mirrors 41 and 42 respectively, the incident angle of the laser beam L incident on these detector mirrors 41 and 42 changes continuously. As a result, the scanner 4 scans the laser beam L on the workpiece 10 along a predetermined path, forming a welding trajectory on the workpiece 10 along the scanning path of the laser beam L.

[0049] Regarding the scanning path of the laser beam L emitted from the scanner 4 onto the workpiece 10, the rotation angles of the detector mirrors 41 and 42 can be changed by appropriately controlling the rotation drive of the detector motors 41a and 42a, thereby allowing the scanning path to change arbitrarily in the X and Y directions.

[0050] The scanner 4 also features a zoom optical system (not shown) that allows for arbitrary changes in positional relationships via a Z-axis motor. The scanner 4 can move the point where the laser converges along the optical axis by driving the Z-axis motor, thereby allowing the laser irradiation point to change arbitrarily in the Z direction.

[0051] The protective glass 43 is disc-shaped and has the function of allowing the laser beam L reflected sequentially by the detectors 41 and 42 to pass through and protecting the interior of the scanner 4.

[0052] Alternatively, the scanner 4 can also be a trepanning head. In this case, the scanner 4 can, for example, have the following structure: a lens with an inclined surface is rotated by a motor to refract the incident laser and direct it to any position.

[0053] The robot control device 5 outputs drive control data to each servo motor of the robot 2 according to the prescribed robot program to control the actions of the robot 2.

[0054] The scanner control device 6 is a control device for adjusting the position of the lens and reflector within the mechanism of the scanner 4. Furthermore, the scanner control device 6 can also be embedded in the robot control device 5.

[0055] The laser control device 7 is a control device for the laser oscillator 3, which controls the output of the laser beam according to instructions from the scanner control device 6. The laser control device 7 can be connected not only to the scanner control device 6, but also directly to the robot control device 5. Alternatively, the laser control device 7 can be integrated with the scanner control device 6.

[0056] The robot teaching pendant 8 is connected to the robot control device 5, and is used by the operator to operate the robot 2. For example, the operator inputs processing information for laser processing through the user interface on the robot teaching pendant 8.

[0057] The program generation device 9 is connected to the robot control device 5 and the scanner control device 6 to generate programs for the robot 2 and the scanner 4. Furthermore, refer to... Figure 3 The program generation device 9 will be described in detail below. In this embodiment, at least the scanner 4 is configured to drive accurately in response to program instructions, and preferably, the robot 2 is also configured to drive accurately in response to program instructions.

[0058] Figure 3 This is a block diagram illustrating the functional structure of the laser processing system 1 according to this embodiment.

[0059] As described above, the laser processing system 1 includes a robot 2, a laser oscillator 3, a scanner 4, a robot control device 5, a scanner control device 6, a laser control device 7, a robot teaching panel 8, and a program generation device 9.

[0060] Below, refer to Figure 3 The operation of the robot control device, scanner control device 6, laser control device 7, and program generation device 9 will be explained in detail.

[0061] The program generation device 9 generates a robot program P1 for the robot 2 in the virtual workspace and a scanner program P2 for the scanner 4 based on CAD / CAM data. Furthermore, the program generation device 9 generates a program for correcting the trajectory of the illumination control points.

[0062] The generated robot program P1 is transmitted to the robot control device 5, and the generated scanner program P2 is transmitted to the scanner control device 6. When the robot program P1 stored in the robot control device 5 is activated by operating the robot teaching pendant 8, a command is sent from the robot control device 5 to the scanner control device 6, thereby activating the scanner program P2 as well.

[0063] The robot control device 5 outputs a signal when the robot 2 moves the scanner 4 to the designated position. The scanner control device 6 drives the optical system inside the scanner 4 according to the signal output from the robot control device 5.

[0064] In addition, the scanner control device 6 instructs the laser control device 7 to output laser light. The robot control device 5, the scanner control device 6, and the laser control device 7 synchronize the robot 2's movements, the scanning of the laser beam axis, and the output of the laser beam by exchanging signals at appropriate timings.

[0065] Robot 2 and scanner 4 share position and timing information to control the laser irradiation point at the desired location within the workspace. Furthermore, robot 2 and scanner 4 start and stop laser irradiation at appropriate timings. Thus, laser processing system 1 is capable of performing laser processing such as welding.

[0066] In addition, the program generation device 9 has built-in 3D modeling software. The operator can manipulate the models of robot 2 and scanner 4 on the computer to confirm the laser irradiation point, coordinate values, etc.

[0067] Furthermore, the program generation device 9 uses the CAD data of the workpiece 10 to generate a 3D model of the workpiece 10, and sets one or more control points on the 3D modeled workpiece 10. Then, the program generation device 9 defines the welding shape for each set control point.

[0068] As mentioned above, the path of the laser illumination point can be represented by a series of points in a coordinate system based on the robot's base within the workspace; therefore, these points are called control points. Control points can be points on the path of the laser illumination point, or they can be points not on the path of the laser illumination point, such as the center of an arc, but necessary for defining the path of the laser illumination point.

[0069] When the definition of control points and welding shapes is completed, the program generation device 9 calculates the robot path for the robot 2 to move and the scanning path based on the laser irradiation point of the scanner 4.

[0070] For a laser irradiation point in three-dimensional space, the posture of robot 2 and the rotation angles of the sensing motors 41a and 42a corresponding to the laser irradiation point based on scanner 4 are not uniquely determined. Therefore, the program generation device 9 has an algorithm to search for the optimal solution that satisfies the conditions. The conditions in the program generation of robot program P1 and scanner program P2 refer to minimizing the processing time, limiting the laser irradiation angle irradiating the workpiece 10, and limiting the posture range of robot 2, etc.

[0071] Then, when the control point is corrected, the scanner control device 6 sends the corrected control point position information and coordinate system orientation information to the program generation device 9.

[0072] The program generation device 9 uses the algorithm described above for searching for the optimal solution to regenerate the robot program P1 and the scanner program P2 based on the corrected control point position information and coordinate system orientation information. It then sends the generated robot program P1 and scanner program P2 back to the scanner control device 6.

[0073] In this way, the program generation device 9 can correct the robot path in the robot program P1 and the laser beam illumination path based on the scanner 4 in the scanner program P2 by generating a robot program P1 and a scanner program P2 that reflect the corrected control points.

[0074] Figure 4A and Figure 4B This is a diagram illustrating an example of path correction for robot 2 in robot program P1. Figure 4A The path of robot 2 before the control points were corrected is shown. Figure 4B The path of robot 2 after the control points have been corrected is shown.

[0075] When Figure 4A When the weld point 20 of the workpiece 18 is magnified, the weld point 20 of the laser irradiated by the scanner 4 is determined according to the robot path 19A in the robot program P1 and the irradiation path of the laser beam irradiated by the scanner 4 in the scanner program P2.

[0076] Therefore, such as Figure 4B As shown, when the position of the welding point 20 changes or control points are added or reduced, the program generation device 9 can regenerate the robot program and scanner program based on the changes in the position of the welding point 20 and the addition or reduction of control points, and regenerate the optimal robot path 19B and laser irradiation path.

[0077] Figure 5 This is a block diagram illustrating the functional structure of the scanner control device 6 according to this embodiment.

[0078] like Figure 5 As shown, the scanner control device 6 includes a trajectory control unit 61, a control point movement unit 62, and a control point storage unit 63.

[0079] The trajectory control unit 61 controls the scanner 4 based on the program for illuminating the trajectory for control point correction, so that when the robot 2 is stopped, the scanner 4 illuminates the workpiece 10 with the trajectory for control point correction for correcting the preset control points.

[0080] The control point movement unit 62 moves the control point based on the control point correction trajectory and according to the operation of the robot teaching control panel 8.

[0081] The control point storage unit 63 stores the position of the control point after it has been moved by the control point moving unit 62, as well as the direction of the coordinate system defined by the control point. Furthermore, the trajectory control unit 61 controls the scanner 4 to project a control point correction trajectory onto the workpiece 10 based on the position of the control point stored in the control point storage unit 63 and the direction of the coordinate system defined by the control point.

[0082] Figure 6A This is a diagram illustrating an example of a trajectory used for control point correction. For example... Figure 6A As shown, the control point correction trajectory 11A has a predetermined length M1 for determining the deviation in the optical axis direction of the laser beam, and a predetermined shape S1 for determining the position of the control point C1 and the direction of the coordinate system defined by the control point. Here, the predetermined length M1 is preferably about 100 mm, for example. In addition, the predetermined shape S1 is preferably a shape that can distinguish between the positive and negative directions.

[0083] Furthermore, the trajectory control unit 61 controls the scanner 4 to irradiate the control point correction trajectory 11A using a guide laser, instead of a processing laser. Thus, the laser processing system 1 can irradiate the control point correction trajectory 11A without processing the workpiece 10.

[0084] Figure 6B It shows the use Figure 6A The diagram shows the action of correcting control points using trajectory 11A. Furthermore, for ease of explanation, Figure 6B This diagram shows a view of workpiece 10 from the side. Here, L1A and L2A represent... Figure 6A The control points in the trajectory 11A are used to correct the laser beam at both ends, guiding it back and forth between L1A and L2A. Figure 6B In this process, the scanner control device 6 corrects the control point C1 for the virtual workpiece 10A in the scanner program to the actual workpiece 10. Therefore, the guide lasers L1A and L2A are corrected to guide lasers L1 and L2.

[0085] exist Figure 6B In the case where control point C1 deviates along the optical axis, if the specified length M1 is small, the difference in deviation of control point C1 will be small, making it difficult for the operator to judge visually. Conversely, if the specified length M1 is large, the deviation along the optical axis will vary more significantly, making it easier for the operator to judge visually.

[0086] Furthermore, a larger specified length M1 makes judgment easier, but the preferred size of the specified length M1 varies depending on factors such as the required accuracy for correcting deviations in the optical axis direction, the distance between the scanner 4 and the workpiece 10, and the size of the portion to be laser-processed. For example, when the distance between the workpiece 10 and the scanner 4 is 500 mm, the specified length M1 is preferably around 100 mm.

[0087] The control point correction trajectory 11A on the virtual workpiece 10A in the scanner program produces a positional deviation on the actual workpiece 10, and this deviation is smaller compared to the instructions in the scanner program. This indicates that the position of the control point correction trajectory 11A in the optical axis direction and in the direction perpendicular to the optical axis has deviated.

[0088] Therefore, by operating the guide lasers L1A and L2A irradiated from the scanner 4, the position and length of the control point correction trajectory 11A are made to match the actual workpiece 10. Thus, the scanner control device 6 can ensure that the guide lasers L1 and L2 properly irradiate the actual workpiece 10.

[0089] exist Figure 6B In this diagram, guide lasers L1A, L2A and L1, L2 represent the scanning range of the guide laser beam. When the position of control point C1 is changed by the scanner control device 6, a repeatedly scanned control point correction trajectory is formed on the surface of workpiece 10. Furthermore, the scanning range of the guide laser beam changes from guide lasers L1A, L2A to guide lasers L1, L2. As a result, the predetermined length M1 of the control point correction trajectory 11A on the surface of workpiece 10 becomes the desired size, completing the teaching correction.

[0090] Here, as mentioned above, the trajectory for control point correction requires a specified length to determine the deviation in the optical axis direction of the laser beam.

[0091] As explained below, the specified length used to determine the deviation in the optical axis direction of the laser beam is calculated based on the distance of the change in the length of the trajectory for visually recognizing the control point correction, the amount of deviation in the optical axis direction of the laser beam to be determined, and the distance between the scanner 4 and the laser irradiation point of the laser beam.

[0092] Figure 6C It is a diagram used to illustrate the deviation in the optical axis direction of a laser beam.

[0093] like Figure 6C As shown, the scanner 4 is positioned directly opposite the workpiece 10, and the workpiece 10 is compared when it is in position A1 with when it is in position B1.

[0094] At this time, the deviation of the laser beam along the optical axis between positions A1 and B1 of workpiece 10 is ΔD. Additionally, as... Figure 6C As shown, the length of the trajectory used for control point correction at position A1 is L, and the length of the trajectory used for control point correction at position B1 is L+ΔL.

[0095] The distances from the electron detectors 41 and 42 within the scanner 4 at positions A1 and B1 on the workpiece 10 are D and D+ΔD, respectively. Furthermore, the relationships between length L and L+ΔL, and distance D and D+ΔD, are as follows.

[0096] L=(ΔL / ΔD)×D

[0097] In reality, the electron microscopes 41 and 42 have two axes, the X-axis and the Y-axis, and the workpiece 10 and the scanner 4 are not necessarily directly aligned. Furthermore, the difference in distance along the optical axis between the center and the periphery of the scanner 4's scanning range will also have an impact. Even considering these factors, the relationship between length L and L+ΔL, and distance D and D+ΔD, can be approximated using the above formulas.

[0098] When correcting the trajectory using the operator's visual recognition control point, for example, the length ΔL can be considered as the minimum length at which the difference can be judged. At this time, if the distance ΔD is set as the allowable deviation in the optical axis direction of the laser beam in laser processing, i.e., the allowable range of the focal distance, the length L (i.e., the specified length mentioned above) can be derived from the distance D between the scanner 4 and the workpiece 10.

[0099] For example, when ΔL = 1mm, meaning that a difference of 1mm can be visually identified, when ΔD = 5mm, meaning that the allowable range of the focal distance is set to 5mm, and D = 500mm, meaning that the distance between the detector microscopes 41 and 42 in the scanner 4 and the laser irradiation point is set to 500mm, the length L (specified length) of the control point correction trajectory is 100mm.

[0100] Furthermore, when using a correction pattern as described later, the visually recognizable length difference ΔL becomes smaller. Additionally, if a length difference of 0.1 mm can be discerned, the length L of the control point correction track can be 10 mm. Furthermore, if the length L of the control point correction track is still set to 100 mm, the position along the optical axis can be adjusted with an accuracy of ΔD = 0.5 mm, or 0.5 mm.

[0101] Next, the operator's actions in correcting the control points will be explained.

[0102] In the control point correction of this embodiment, the operator moves the robot 2 to the vicinity of the control point and stops it through manual or semi-automatic operation. Then, when the guide laser is irradiated by the scanner 4, the operator moves the scanner 4 while visually recognizing the shape of the control point correction trajectory irradiated on the workpiece 10. Thus, the operator can correct the position of the control point and the direction of the coordinate system defined by the control point.

[0103] Here, manual operation refers to the operator manipulating the robot teaching pad 8 to change the posture of the robot 2 and move the scanner 4 to the desired position. Semi-automatic operation, on the other hand, refers to using a robot program generated by the program generation device 9 for desired control points within the 3D model to move the scanner 4 to the vicinity of the control points, and a scanner program for irradiating the guide laser to change the posture of the robot 2, thereby moving the scanner 4 to the desired position.

[0104] The manual operation is performed as shown below.

[0105] (1) Drive robot 2 to move the scanner 4 fixed to the front end 22a of arm 22 of robot 2 to the vicinity of the control point to be corrected.

[0106] (2) With the robot 2 stationary, a guide laser is irradiated onto the workpiece 10. At this time, the scanner control device 6 uses the guide laser to repeatedly scan the trajectory for control point correction at high speed via the electroscopes 41 and 42.

[0107] (3) The operator can use the robot teaching control panel 8 to instruct the X, Y, and Z axes of the guiding laser, as well as the rotation around each axis. The operator's instructions are transmitted from the robot control device 5 to the scanner control device 6, thereby enabling the control point correction trajectory for high-speed repeated scanning to move and rotate in space.

[0108] (4) While visually recognizing the control point correction trajectory projected on the workpiece 10, the operator operates the control point correction trajectory through the robot teaching control panel 8 to achieve the desired position and desired size.

[0109] (5) When the position of the control point and the orientation of the coordinate system of the control point correction trajectory are determined, the operator saves the data related to the control point correction trajectory in the storage device (not shown) of the laser processing system 1, completing the teaching correction. In addition, when the operator operates the control point correction trajectory through the robot teaching operation panel 8, the robot 2 is stationary, and the position and orientation of the scanner 4 do not change.

[0110] After stopping the scanner 4 near the control point to be corrected, the operator operates the robot teaching panel 8 to start the program for illuminating the trajectory for control point correction.

[0111] In manual operation, it is difficult to irradiate the guide laser near the control point to be corrected. Therefore, after the scanner 4 starts the program for irradiating the trajectory for control point correction, the guide laser is irradiated directly below the scanner 4.

[0112] In contrast to manual operation, the robot program and scanner program generated by the program generation device 9 are used in semi-automatic operation. The operator starts the robot program and stops the robot 2 and brings it to a standstill when the scanner 4 reaches the vicinity of the control point to be corrected initially. The subsequent operations are the same as (2) to (5) in manual operation. In semi-automatic operation, the operator then moves the robot 2 from its stationary position to the vicinity of the next control point to be corrected according to the robot program and continues the correction work.

[0113] Furthermore, multiple types of programs for correcting the irradiation control points can be prepared in advance and used separately according to the purpose. For example, a small control point correction trajectory can be used for narrow areas of the workpiece 10, while a large control point correction trajectory can be used for wide areas of the workpiece 10. Additionally, a long control point correction trajectory can be used for straight sections along the mating portion, and for sections like the cap of a cylinder, if the center point is a control point, a control point correction trajectory corresponding to that control point can be used. Furthermore, a three-dimensional control point correction trajectory can be used for cylindrical surfaces.

[0114] Figure 6D This is another example of a trajectory used for control point correction. (See diagram below.) Figure 6D As shown, the control point correction trajectory 11B is repeatedly scanned at a predetermined cycle by the scanner control device 6. The predetermined cycle is preferably around 50 ms. Thus, based on the visual persistence effect, the operator can perceive that the control point correction trajectory is being continuously drawn.

[0115] Figure 6E This is a diagram showing an example of correction pattern 12 used to correct the trajectory for control point correction. (See diagram for example.) Figure 6E As shown, the correction pattern 12 has the same length and shape as the control point correction trajectory and can be disposed on the workpiece 10. The correction pattern 12 can also be, for example, a label that can be pasted on the workpiece 10, a card-like item that can be disposed on the workpiece 10, a paper pattern, a magnet, etc. In addition, the correction pattern 12 can also be pre-printed on the workpiece 10.

[0116] By using such a correction pattern 12, the control point correction trajectory irradiated onto the workpiece 10 can be compared with the correction pattern 12, which has the same length and shape as the control point correction trajectory in the scanner program used to control the scanner 4.

[0117] Thus, the operator can confirm and correct the position, direction, size, and deformation of the control point correction trajectory by comparing it with the control point correction trajectory in the scanner program.

[0118] Figure 6F This diagram illustrates the action of correcting control point C2 using trajectory 11B for control point correction. (As shown...) Figure 6F As shown, the control point moving unit 62 moves the control point C2, and the trajectory control unit 61 moves the control point correction trajectory 11B based on the position of the moved control point and the direction of the coordinate system defined by the control point.

[0119] The control point movement unit 62 can move the control point C2 in an orthogonal coordinate system such as the X, Y, and Z axes, and in a rotating coordinate system such as the w, p, and r axes (yaw, pitch, and roll). That is, the control point movement unit 62 can move the control point C2 with six degrees of freedom.

[0120] The program used for trajectory correction of the illumination control point controls the scanner 4 to: illuminate the guide laser starting from the illumination start point, return to the start point, and repeat these actions at high speed. The position of the laser illumination point at startup and the direction through the coordinate system defined by the control point are stored as a position and direction vector in the coordinate system with the base axis of robot 2 as the origin, and are stored in the robot control device 5 or the scanner control device 6.

[0121] When the operator operates the robot teaching pendant 8 to move the control point to correct the trajectory, the program for correcting the trajectory changes the irradiation point by 0.1 mm each time it returns to the irradiation start point, for example, each time in the positive direction of the X-axis. At the same time, the scanner control device 6 stores the changed irradiation start point as the starting point of the changed irradiation start point.

[0122] After the control point is moved to the desired position using the correction trajectory, that is, after the control point is moved to the desired position and coordinate system orientation, the operator uses the robot teaching pendant 8 to notify the scanner control device 6 that the movement of the control point has ended.

[0123] The scanner control device 6 transmits the modified control point information to the program generation device 9. Furthermore, the program generation device 9 can also transmit the modified control point information as CAD data to the CAD system (not shown). The position of the control point and the orientation of the coordinate system defined by the control point can take various data forms, such as values ​​of the coordinate system with the robot 2's base axis as the origin, and the corrected movement amount of the control point. Additionally, during manual operation, the scanner control device 6 can also register any new position and coordinate system orientation as a control point.

[0124] Figure 7A and Figure 7B This is another example of a trajectory used to illustrate control point correction. Figure 7A This is a diagram showing components 13 and 14 welded by laser processing system 1. (See diagram for reference.) Figure 7A As shown, component 14 is mounted on cylindrical component 13, and laser processing system 1 welds a portion of the contact area between component 13 and component 14.

[0125] Figure 7B This is a diagram showing the welded portion and the trajectory for control point correction by the laser processing system 1. Figure 7B This is a top view of components 13 and 14. (See diagram below.) Figure 7B As shown, the laser processing system 1 welds component 13 to component 14 at welding portions 15A to 15F.

[0126] In particular, when the vicinity of the welded portion 15E is magnified, components 13 and 14 are welded near the end 14A of component 14 via the welded portion 15E. Furthermore, the trajectory control unit 61 controls the scanner 4 to irradiate the control point correction trajectory 11C toward the end 14A of component 14.

[0127] The control point correction trajectory 11C has a predetermined length along the end 14A and two L-shaped features symmetrical about the control point C4. Furthermore, the trajectory control unit 61 shuts off the guide laser, refraining from illuminating only the control point C4, allowing the operator to clearly visually identify the control point C4.

[0128] Furthermore, when the operator corrects the control point C4, the control point C4 is accurately positioned on the end 14A of the component 14 by moving the straight portion of the control point correction trajectory 11C, which includes the control point C4, on the end 14A of the component 14.

[0129] Furthermore, the operator can accurately adjust the position of control point C4 and the orientation of the coordinate system defined by the control point by adjusting the positions of the short line segments at both ends of the control point correction trajectory 11C. Additionally, the operator can confirm and correct the deviation between the end 14A of component 14 and the optical axis direction of the laser beam based on the specified length of the control point correction trajectory 11C.

[0130] Figures 8A to 8D This is another example of a trajectory used to illustrate control point correction. Figure 8A A top view of component 16 welded by laser processing system 1 is shown. Figure 8B A perspective view of component 16 welded by laser processing system 1 is shown. (As shown) Figure 8A As shown, component 16 is welded at welding portions 17A to 17C using laser processing system 1. Additionally, as... Figure 8B As shown, component 16 has a flange portion 16A and a pipe portion 16B.

[0131] Figure 8C This is a diagram showing the trajectory 11D used for control point correction. (Example) Figure 8C As shown, the control point correction trajectory 11D has a fan shape, and control point C5 is positioned on the portion of the control point correction trajectory 11D that overlaps with the welding portion 17A. Furthermore, Figure 8C The control point correction trajectory 11D is shown when welding part 17A is performed, but the control point correction trajectory 11D is also irradiated to the positions corresponding to welding parts 17B and 17C respectively when welding parts 17B and 17C are performed.

[0132] Figure 8DThis is a diagram showing laser beams L illuminating from different positions A and B. (As shown...) Figure 8D As shown, at position A, the scanner 4 welds the flange portion 16A to the pipe portion 16B from the inner peripheral side of the flange portion 16A, and at position B, the scanner 4 welds the outer periphery of the flange portion 16A to the pipe portion 16B from the outer peripheral side of the pipe portion 16B.

[0133] In this case, the control point correction trajectory 11D also moves in the direction of the optical axis of the laser beam L. In addition, when the operator corrects the control point C5, the control point C5 is accurately positioned on the welding parts 17A to 17C by moving the fan shape of the control point C5, which includes the control point correction trajectory 11D, on the welding parts 17A to 17C.

[0134] Figure 9 This is a flowchart illustrating the processing flow of the laser processing system 1 according to this embodiment.

[0135] In step S1, the robot control device 5 controls the robot 2 based on the robot program, so that the scanner 4, which is capable of scanning the workpiece 10 with a laser beam, moves relative to the workpiece 10.

[0136] In step S2, the robot control device 5 controls the robot 2 based on the robot program to stop the robot 2.

[0137] In step S3, the trajectory control unit 61 controls the scanner 4 so that, while the robot 2 is stopped, the scanner 4 illuminates the workpiece 10 with a trajectory for control point correction.

[0138] In step S4, the control point moving unit 62 moves the control point based on the control point correction trajectory.

[0139] In step S5, the control point storage unit 63 stores the position of the moved control point and the direction of the coordinate system defined by the control point.

[0140] In step S6, the trajectory control unit 61 controls the scanner 4 to irradiate the workpiece 10 with a trajectory for control point correction based on the position of the moved control point and the direction of the coordinate system defined by the control point.

[0141] As described above, the laser processing system 1 according to this embodiment includes: a scanner 4 capable of scanning a workpiece 10 with a laser beam; a robot 2 that moves the scanner 4 relative to the workpiece 10; and a scanner control device 6 that controls the scanner 4. The scanner control device 6 has a trajectory control unit 61 that controls the scanner 4 such that, when the robot 2 is stopped, the scanner irradiates the workpiece 10 with a control point correction trajectory for correcting pre-set control points. The control point correction trajectory has a predetermined length for determining the deviation in the optical axis direction of the laser beam, and a predetermined shape for determining the position of the control point and the direction of the coordinate system defined by the control point.

[0142] Therefore, the laser processing system 1 can correct the control points using a control point correction trajectory. Thus, the laser processing system 1 can easily correct the control points without moving the robot 2, solely through the movement of the scanner 4.

[0143] Furthermore, the laser processing system 1 can correct control points without using teaching jigs, additional light sources, or cameras and analysis devices for image analysis. Additionally, the laser processing system 1 simplifies operation by using only the scanner 4 to deflect the optical axis of the guide laser. Moreover, the laser processing system 1 uses a guide laser on the same axis as the processing laser, ensuring accurate teaching correction results.

[0144] Furthermore, the laser processing system 1 can accurately adjust the position of the laser beam along the optical axis, the position of the plane perpendicular to the optical axis, the position of the control points, the direction of the coordinate system defined by the control points, and the tilt of the workpiece 10 by using a control point correction trajectory. Especially in laser welding, there are many cases where the laser is irradiated along the shape of a line, such as in butt welding or edge welding. Therefore, by using the laser processing system 1 according to this embodiment, the direction and position of the laser beam can be appropriately adjusted.

[0145] Furthermore, the trajectory control unit 61 controls the scanner 4 to repeatedly scan the control point correction trajectory at a predetermined cycle. Therefore, based on visual persistence, the operator can perceive that the control point correction trajectory is being continuously drawn. Consequently, the operator can confirm and correct the position, direction, size, and deformation of the control point correction trajectory by perceiving it.

[0146] Furthermore, the control point correction trajectory irradiated onto the workpiece 10 has the same length and shape as the control point correction trajectory in the scanner program used to control the scanner 4, and can be compared with the correction pattern 12 that can be configured on the workpiece 10. Thus, the operator can confirm and correct the position, direction, size, and deformation of the control point correction trajectory by comparing it with the control point correction trajectory in the scanner program.

[0147] In addition, the scanner control device 6 also includes: a control point movement unit 62, which moves the control point based on the control point correction trajectory; and a control point storage unit 63, which stores the position of the moved control point and the direction of the coordinate system defined by the control point. The trajectory control unit 61 controls the scanner 4 to illuminate the control point correction trajectory onto the workpiece 10 based on the position of the control point and the direction of the coordinate system defined by the control point.

[0148] Therefore, the laser processing system 1 can correct the position of the control points within the scanning range of the scanner 4 and the orientation of the coordinate system defined by the control points without moving the robot 2. Thus, the laser processing system 1 can correct the control points simply by guiding the laser scan without changing the posture of the robot 2.

[0149] Furthermore, the specified length for the deviation in the optical axis direction of the laser beam is calculated based on the distance of the change in the length of the trajectory for visually recognizing the control point correction, the amount of deviation in the optical axis direction of the laser beam to be determined, and the distance between the scanner 4 and the laser irradiation point of the laser beam. Thus, the laser processing system 1 can appropriately determine the deviation in the optical axis direction of the laser beam.

[0150] The embodiments of the present invention have been described above. The laser processing system 1 described above can be implemented by hardware, software, or a combination thereof. Furthermore, the control method performed by the laser processing system 1 described above can also be implemented by hardware, software, or a combination thereof. Here, "implemented by software" means implemented by a computer reading and executing a program.

[0151] Programs can be stored and supplied to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., hard disk drives), optical-magnetic recording media (e.g., optical discs), CD-ROM (Read Only Memory), CD-R, CD-R / W, semiconductor memories (e.g., mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)).

[0152] Furthermore, the above-described embodiments are preferred embodiments of the present invention, but the scope of the present invention is not limited to the above-described embodiments. Various modifications can be made to achieve the same result without departing from the spirit of the present invention.

[0153] Explanation of reference numerals in the attached figures

[0154] 1: Laser processing system; 2: Robot; 3: Laser oscillator; 4: Scanner; 5: Robot control device; 6: Scanner control device; 7: Laser control device; 8: Robot teaching pendant; 9: Program generation device; 10: Workpiece; 61: Trajectory control unit; 62: Control point movement unit; 63: Control point storage unit.

Claims

1. A laser processing system, comprising: A scanner that can scan a workpiece using a laser beam; A moving device that moves the scanner relative to the workpiece; and Scanner control device, which controls the scanner, in, The scanner control device includes a trajectory control unit that controls the scanner so that, when the moving device is stopped, the scanner illuminates the workpiece with a control point correction trajectory for correcting pre-set control points. The control point correction trajectory has a predetermined length for determining the deviation in the optical axis direction of the laser beam, and a predetermined shape for determining the position of the control point and the direction of the coordinate system defined by the control point. The control point correction trajectory irradiating the workpiece has the same length and shape as the control point correction trajectory in the scanner program used to control the scanner, and can be compared with the correction pattern that can be configured on the workpiece.

2. The laser processing system according to claim 1, wherein, The scanner control device also includes: A control point moving unit moves the control point based on a trajectory for control point correction; and The control point storage unit stores the position of the control point after movement and the orientation of the coordinate system defined by the control point. The trajectory control unit controls the scanner based on the position of the control point and the direction of the coordinate system defined by the control point, so that the scanner illuminates the workpiece with the trajectory for control point correction.

3. The laser processing system according to claim 1, wherein, The specified length used to determine the deviation in the optical axis direction of the laser beam is calculated based on the distance from which the change in the length of the trajectory for correcting the control point can be visually identified, the amount of deviation in the optical axis direction of the laser beam, and the distance between the scanner and the laser irradiation point of the laser beam.

4. The laser processing system according to claim 1, wherein, The trajectory control unit controls the scanner so that the scanner repeatedly scans the control point correction trajectory at a predetermined period.

5. A control method for a laser processing system, comprising the following steps: The scanner, capable of scanning the workpiece with a laser beam, is moved relative to the workpiece. A moving device used to stop the scanner relative to the workpiece; as well as The scanner is controlled such that, while the moving device is stopped, the scanner illuminates the workpiece with a control point correction trajectory for correcting pre-set control points. The control point correction trajectory has a predetermined length for determining the deviation along the optical axis of the laser beam, and a predetermined shape for determining the position of the control point and the direction of the coordinate system defined by the control point. The control point correction trajectory irradiating the workpiece has the same length and shape as the control point correction trajectory in the scanner program used to control the scanner, and can be compared with the correction pattern that can be configured on the workpiece.

6. The control method for the laser processing system according to claim 5, wherein, The steps of controlling the scanner include the following steps: controlling the scanner based on the position of the control point and the direction of the coordinate system defined by the control point, such that the scanner illuminates the workpiece with the trajectory for correction of the control point.

7. The control method for the laser processing system according to claim 5, wherein, The specified length used to determine the deviation in the optical axis direction of the laser beam is calculated based on the distance from which the change in the length of the trajectory for correcting the control point can be visually identified, the amount of deviation in the optical axis direction of the laser beam, and the distance between the scanner and the laser irradiation point of the laser beam.

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