Laser processing device

Abstract

Provided is a laser processing device which involves adjustment of a reference optical path length by a reference arm, and in which a cycle time can be reduced. A laser processing device 1 is provided with: a processing head 12 that includes at least one laser light deflection mechanism 13 for radiating laser light onto a workpiece 40; a beam control unit 201 that controls the laser light deflection mechanism 13; at least one measurement light deflection mechanism 34 that is optically linked to the processing head 12; a measurement light control unit 202 that controls the measurement light deflection mechanism 34; an optical measurement unit 30 that uses measurement light to obtain a measurement value related to a measurement point on the workpiece 40; a measurement range adjustment mechanism 324 that executes optical path length adjustment in order to adjust a reference optical path length or a measurement optical path length; and a determination unit 203 that, before the optical measurement unit 30 obtains the measurement value, determines whether or not to execute the optical path length adjustment. The measurement range adjustment mechanism 324 executes the optical path length adjustment if a signal for the optical path length adjustment has been received from the determination unit 203.

Description

Laser processing apparatus

[0001] The present disclosure relates to a laser processing apparatus.

[0002] Conventionally, an apparatus for measuring the distance to a workpiece using a laser beam for length measurement has been known.

[0003] Japanese Patent Application Laid-Open No. 2023-505772, Japanese Patent Application Laid-Open No. 2020-185651, Japanese Patent Application Laid-Open No. 2022-110864

[0004] However, in a conventional OCT sensor (laser rangefinder) using a laser beam for length measurement, the reference arm of the OCT sensor was adjusted every time a measurement was made. For the adjustment of the reference arm, a stepping motor with low responsiveness was often used, and if the number of adjustments of the reference arm increased, the cycle time, which is the time required for the entire processing, might become longer.

[0005] An object of the present disclosure is to provide a laser processing apparatus that reduces the cycle time.

[0006] The present disclosure includes a processing head including at least one laser beam deflection mechanism for irradiating a workpiece with a laser, a beam control unit for controlling the laser beam deflection mechanism, at least one measurement beam deflection mechanism optically coupled to the processing head, a measurement beam control unit for controlling the measurement beam deflection mechanism, an optical coherence interferometer unit for obtaining a measurement value regarding a measurement point of the workpiece using a measurement beam, a measurement range adjustment mechanism for performing an optical path length adjustment for adjusting a reference optical path length or a measurement optical path length, and a determination unit for determining whether to perform the optical path length adjustment before the optical coherence interferometer unit obtains the measurement value. The measurement range adjustment mechanism is a laser processing apparatus that performs the optical path length adjustment when receiving a signal for the optical path length adjustment from the determination unit.

[0007] According to the present disclosure, it is possible to provide a technique capable of reducing the cycle time in a laser processing apparatus involving adjustment of the reference optical path length by a reference arm.

[0008] This figure shows the overall configuration including the laser processing apparatus and related devices according to this embodiment. This figure shows the reference arm according to this embodiment. This figure shows the relationship between the processing beam, the measurement light, and the workpiece according to this embodiment. This figure shows the distances according to this embodiment. This figure shows the distances according to this embodiment. This figure shows the model according to this embodiment. This figure shows an example of adjusting the reference arm according to this embodiment. This figure shows the number of adjustments to the reference arm according to this embodiment. This figure shows the processing flow of the laser processing apparatus according to the first control example. This figure shows the number of adjustments to the reference arm according to the first control example. This figure shows the number of adjustments to the reference arm according to the second control example. This figure shows an example of adjusting the reference arm according to the second control example. This figure shows the processing flow of the laser processing apparatus according to the third control example. This figure shows the number of adjustments to the reference arm according to the third control example. This figure shows an example of adjusting the reference arm according to the third control example. This figure shows the evaluation items of the system operation plan according to this embodiment. This figure shows the evaluation items of the system operation plan according to this embodiment. This is a schematic block diagram showing the configuration of the computer according to this embodiment. This figure shows an example of an optical measurement unit according to this embodiment.

[0009] Embodiments of this disclosure will be described in detail below with reference to the drawings. The drawings used in this description may omit some of their components for illustrative purposes. Furthermore, the same reference numerals in the drawings and this specification indicate the same elements.

[0010] (Overall Configuration) Figure 1 is a schematic diagram showing the overall configuration of a laser processing apparatus 1 and related devices according to one embodiment of the present disclosure. The laser processing apparatus 1 comprises a galvanometer scanner 10, a control device 20, a measurement system 30 (for example, OCT (Optical Coherence Tomography)), and a transport device 70. The galvanometer scanner 10 comprises a laser light source 11 and a processing head 12.

[0011] The galvanometer scanner 10 performs welding by irradiating a workpiece on a moving stage with a processing beam. However, the configuration is not limited to placing the workpiece on a moving stage; the method of placing the workpiece can be changed as appropriate.

[0012] The laser light source 11 generates laser light by internally oscillating a laser in response to commands (such as laser power commands) from the control device 20. The laser light source 11 includes a fiber laser oscillator, a pulsed laser oscillator, a direct diode laser (DDL), and CO2. ２ Any type of laser oscillator may be used, such as a laser oscillator or a solid-state laser (YAG laser) oscillator. The laser light source 11 supplies the generated laser light to the processing head 12.

[0013] Optical components 50, such as lenses 51-53 and mirrors 54-56, are arranged on the processing head 12. Of the optical components 50, mirror 54 is a dichroic mirror that reflects the processing beam while transmitting measurement light.

[0014] The processing head 12 can be composed of a wobble head with a wobble function and a polygon mirror. Alternatively, the processing head 12 may be a device placed on a moving stage or a device connected to a robot. Thus, the configuration of the processing head 12 is not particularly limited.

[0015] The laser beam deflection mechanism 13 controls the irradiation position by adjusting the position and angle of optical components such as mirrors 55-56 based on commands from the control device 20.

[0016] The control device 20 is configured using a computer equipped with memory such as ROM (read-only memory) and RAM (random access memory), a CPU (Control Processing Unit), and a communication control unit, all connected to each other via a bus. The functions and operations of each functional unit, described later, are achieved through the cooperation of the CPU, memory, and control programs stored in the computer. The control device 20 may also be configured as a CNC (Computer Numerical Controller) or a PLC (Programmable Logic Controller), or it may be connected to a higher-level computer that outputs machining programs and other machining conditions.

[0017] The control device 20 of this embodiment includes a beam control unit 201 that controls the laser light deflection mechanism 13 and the laser light source 11, a measurement light control unit 202 that controls the measurement light deflection mechanism 34 via the OCT system controller 31, a determination unit 203, and a buffer unit 204. The control device 20 may further have a transport device controller function.

[0018] Furthermore, various functions may be added to the control device 20. For example, a welding monitoring system using an image sensor such as a CMOS or CCD, or a welding monitoring system using a photodiode, may be connected to the control device 20.

[0019] Hardware related to various additional functions for the control device 20 may be mounted independently, or it may be mounted optically coupled to the processing head 12 or the OCT scanner 33.

[0020] The measurement system 30 is a sensor system that determines the difference in optical path length between the reflected light at the measurement point and the reference light from the interference fringes of the two lights. The measurement system 30 makes it possible to monitor the keyhole depth (≒ weld depth) by taking measurements during welding. This makes it possible to directly determine the quality of the weld.

[0021] The measurement system 30 may be an optical measurement unit such as a camera, photodiode, or optical component without a light receiver.

[0022] As an example, the measurement system 30 is an optical coherence interferometer unit comprising an OCT system controller 31, a measurement light source 32, an OCT scanner 33, and a measurement light deflection mechanism 34.

[0023] The OCT system controller 31 is a measurement light control unit that communicates with the control device 20 and controls the operation of the measurement light source 32 and the OCT scanner 33. The OCT system controller 31 in this embodiment also has a calculation unit 35 for analyzing keyholes.

[0024] The measurement light source 32 is a light source that generates measurement light used in the optical coherence interferometer. Optical components 60 such as lenses 57 and mirrors 58-59 are arranged in the OCT scanner 33.

[0025] The measurement light deflection mechanism 34 can be a device consisting of polygon mirrors. In this embodiment, the measurement light deflection mechanism 34 optically couples the measurement light to the optical path formed by the optical component 50 of the processing head 12 using mirrors 58 to 59. The measurement light deflection mechanism 34 operates based on commands from the OCT system controller 31.

[0026] The transport device 70 is a device for transporting the galvanometer scanner device 10 to the workpiece processing position. The transport device 70 may be a robot, a single-axis machining center, or a multi-axis machining center.

[0027] The motion planning device 80 is a device that plans the operation for each device controlled by the control device 20. The motion planning device 80 can pre-generate operation results, i.e., simulation results, based on the settings for each model. The motion planning device 80 provides these simulation results to the operator, who can then verify the simulation results, change various parameters, and re-verify the simulation results based on the changed parameters before actually operating each device. The motion planning device 80 can communicate with the control device 20 and provide operation information for each device controlled by the control device 20.

[0028] (Reference Arm) Figure 2 shows a reference mirror 323 and a reference arm 324 provided and used in the measurement system 30. The reference mirror 323 and the reference arm 324 may be provided, for example, in the measurement light source 32.

[0029] The reference arm 324 (also referred to as the optical path length adjustment mechanism or measurement range adjustment mechanism) performs optical path length adjustment, thereby adjusting the reference optical path length and / or the measured optical path length. Optical path length adjustment is performed by moving the position of the reference mirror 323 using a motor. The reference arm 324 is roughly like the focusing lens of a camera, and is a mechanism that adjusts the measurement range in which length is measured by optical interference when measuring length with an optical interferometer. For example, the adjustment is performed according to the distance to the object to be measured.

[0030] The measurement system 30 is a device for measuring optical interference, and its measurement range depends on the wavelength resolution of the line sensor 326. For example, the wavelength resolution of the line sensor 326 is 2048 pixels, and the detection range is 0 to 12 mm. If the optical path length difference falls outside this detection range, interference will not be measured.

[0031] The measurement of the optical path length difference will now be explained. In path 1 in Figure 2, the light from the light-emitting diode 321 travels in the following order: beam splitter 322, reference mirror 323, beam splitter 322, diffraction grating 325, and reaches the line sensor 326. In path 2 in Figure 2, the light from the light-emitting diode 321 travels in the following order: beam splitter 322, workpiece 40, beam splitter 322, diffraction grating 325, and reaches the line sensor 326. If there is an optical path length difference between the reference optical path length in path 1 and the measured optical path length in path 2, that optical path length difference is detected by the line sensor 326.

[0032] For example, when the measurement range adjustment value is set to 500 mm, the optical path length in path 1 is 500 mm. In this case, if the detection range is 0 to 12 mm, the measurement range is 500 mm to 512 mm. Here, when the optical path length in path 2 is 506 mm, the line sensor 326 measures the interference of light with an optical path length difference of 6 mm. As a result, the distance to the workpiece is measured to be 506 mm.

[0033] The distances actually used in the calculations may be converted using a coefficient for converting distances in a medium to distances in a vacuum (optical path length). The medium includes solids such as glass and lenses, gases such as air and nitrogen gas, liquids such as water and coolant (for example, when the entire system is submerged in water), and plasma generated during welding.

[0034] The optical path length or optical path difference may be converted to the length of the path. In this disclosure, for ease of understanding, the one-way optical path length or optical path difference is used, but in practice, the round-trip optical path length or optical path difference is used. The round-trip optical path length or optical path difference is twice the one-way optical path length or optical path difference.

[0035] (Definition of Terms) The measuring light is the light emitted from the measuring light source 32. The measuring light is used, for example, to measure the keyhole depth after keyhole creation on a workpiece by a processing beam, as shown in Figure 3. The detection range is the range of optical path length difference that the measurement system can detect. The detection range is also called the range in which interference under the OCT principle can be observed, or the focus range. For example, if the wavelength resolution of the line sensor 326 is 2048 pixels, the theoretical detection range is 0 to 12 mm. The detection range actually used is narrower than this, for example, set to 1 to 11 mm. The measurement range is the range of distance measured by the measurement system. The measurement range is determined by the measurement range adjustment value set by adjusting the reference arm and the detection range. For example, if the measurement range adjustment value is 500 mm and the detection range is 1 to 11 mm (i.e., the width is 10 mm), the measurement range is 500 mm to 510 mm. The measurement range adjustment value is the minimum value of the measurement range. The measurement range adjustment value is set by adjusting the reference arm so that the reference optical path length is equal to the measurement range adjustment value. The reference optical path length may be determined by taking into account the length of the path, such as the optical fiber used.

[0036] The workpiece distance refers to the distance from the galvanometer scanner to the workpiece surface at a given point in time during the measurement of a single spot weld. One spot weld represents one spot weld. One spot weld performs processing on one weld path and generates one weld shape. Multiple weld shapes may be generated by one spot weld. The distance from the galvanometer scanner to the workpiece surface on the optical path of the measurement light is the distance from the reflection point of the measurement light at mirrors 55-56 inside the galvanometer scanner to the workpiece surface. Instead of the reflection point of the measurement light at mirrors 55-56, the position of the galvanometer scanner's output port or the output port protection window may be used to calculate the workpiece distance. Furthermore, the length of the path inside the measurement light source and the optical fiber used may also be considered. The shortest workpiece distance refers to the shortest workpiece distance during the measurement of a single spot weld (see Figure 4). In other words, the shortest workpiece distance refers to the distance from the galvanometer scanner to the workpiece surface on the optical path of the measurement light at the point in time when the distance from the galvanometer scanner to the workpiece surface on the optical path of the measurement light is the shortest possible distance during the measurement of a single dot. The shortest workpiece distance is defined similarly in measurement operations involving on-the-fly operation as shown in Figure 5. On-the-fly operation is an operation in which the galvanometer scanner operates while the transport device (robot) moves, and the laser is irradiated along the shape of the processing point. The extension distance is the distance that needs to be extended from the shortest workpiece distance due to oblique firing, etc., during dot measurement (see Figures 4 and 5). The extension distance is also called the distance obtained by subtracting the shortest workpiece distance from the workpiece distance. The extension distance changes depending on the movement of the processing head, the movement of the workpiece, the irradiation angle, the shape of the workpiece, etc. The extension distance may be set to a fixed value to reduce the amount of calculation. In on-the-fly operation, the extension distance may fluctuate depending on the position of the galvanometer scanner. The longest extension distance is the longest extension distance during the measurement of a single dot. The maximum elongation distance is calculated by subtracting the shortest workpiece distance from the longest workpiece distance in a single measurement. The measurement distance is the depth of the object being measured (for example, a keyhole in welding) at a specific point in time during the measurement of a single point (see Figure 3). The measurement distance is also called the distance from the workpiece surface to the bottom of the keyhole (i.e., the measurement point).If no processing has been performed on the object to be measured, the measurement point is on the workpiece surface, and the measurement distance indicates the distance to the workpiece surface. The measurement distance is set for each dot that is processed. The measurement distance is different from the actual processing distance. If the thickness of the workpiece is 2.5 mm and the expected welding depth is 2.0 mm, the measurement distance may be set to 3.0 mm to allow for a slight margin. Also, if the weld bead after welding is to be considered, the measurement distance may be the height of the bead. In this case, the measurement distance is set to a negative value. The measurement point distance is the distance from the galvanometer scanner to the measurement point on the optical path of the measurement light at a certain point in time during the measurement of one dot. The measurement point distance is equal to the sum of the workpiece distance and the measurement distance. The longest measurement point distance is the longest measurement point distance in the measurement of a single dot. The longest measurement point distance may be calculated by the sum of the shortest workpiece distance, the longest extension distance, and the maximum measurement distance at one dot. If the range from the shortest workpiece distance to the longest measurement point distance is within the measurement range, the optical path length difference can be measured. Cycle time is the total time required for the entire machining process. Cycle time includes the time for adjusting the reference arm, the time for moving the conveyor, and the time required for welding.

[0037] (Description of Models) Referring to Figure 6, information about each model used in the system operation planning of the laser ranging system is described below. The laser ranging system includes a galvanoscanner model for the galvanoscanner 10, a transporter model for the transporter 70, a measurement system model for the measurement system 30, and a workpiece model for the workpiece. Each model has the following model information.

[0038] The galvanometer scanner model information includes the mechanism information of the galvanometer scanner. The galvanometer scanner model information includes A: holding point, B: laser emission point, C: laser emission range, and D: laser focal range.

[0039] The conveying device model information includes the mechanism information of the conveying device. The conveying device model information includes E: holding point, F: movable axis 1, and G: movable axis 2. The model of the conveying device 70 may be alternatively configured by a robot, a single-axis machining center (i.e., a linear motion machining center), or a multi-axis machining center.

[0040] The measurement system model information includes the mechanism information of the measurement system. The measurement system model information includes H: the measurement range and I: the measurement range adjustment value. When the measurement system 30 is a camera, the measurement range adjustment value is determined based on the focus lens position. When the measurement system is an OCT sensor, the measurement range adjustment value is determined based on the focus lens position and the reference arm position.

[0041] The workpiece model information includes J: the center coordinates of the processing point, K: the shape of the processing point, L: the 3D model of the workpiece to be processed, and M: the support device for the workpiece to be processed. There may be a plurality of J, K, L, and M respectively. L may not exist in the model of the workpiece to be processed.

[0042] Each model information is not limited to the above information. For example, each model information may further have 3D-CAD information, current values, and respective conversion coefficients.

[0043] (Example of adjusting the reference arm) Referring to FIG. 7, an example of adjusting the reference arm will be described. In FIG. 7, measurements are performed in the order of the left measurement light, the middle measurement light, and the right measurement light. In this measurement method, every time different measurements are performed, that is, every time a dot measurement is made, the reference arm is adjusted. In FIG. 7, three dot measurements are performed, and a total of three adjustments of the reference arm are carried out.

[0044] FIG. 8 shows the number of adjustments when the example of adjusting the reference arm shown in FIG. 7 is used in a welding program including 12 dots. The reference arm is adjusted during the measurement of all 12 dots in the welding program. Therefore, the total number of reference arm adjustments for dot numbers 1 to 12 is 12 times. In the first to third control examples described below, by adopting a configuration to reduce the number of reference arm adjustments, the cycle time is shortened.

[0045] In the present disclosure, the description is made on the premise of a welding program, but it may also be applicable to a processing program without welding. In that case, it may be read as if the same operation is performed with the welding output set to 0. When welding is not performed, for example, it includes the case of checking the state of the workpiece in the pre-welding process, the case of measuring the position of the feature points (e.g., step portions, etc.) of the workpiece in the pre-welding process and performing position correction, or the case of observing the bead shape after welding in the post-welding process. Also, as something that changes the welding depth, a distance range assumed for the object may be set. When considering the welding bead, it is also assumed that there are convex portions in addition to the recesses. In this case, the distance range corresponding to the welding depth may be set to a negative value. In the case of a negative value, the shortest workpiece distance is replaced by the shortest workpiece distance minus the distance range corresponding to the welding depth. Also, the welding path is simply replaced by a path, which refers to the scanning path of the galvanometer scanner. The welding shape is simply replaced by a shape, which refers to the scanning shape of the galvanometer scanner.

[0046] <First Control Example> (Processing Flow of Laser Processing Apparatus) Referring to FIGS. 9 and 10, the processing flow executed by the laser processing apparatus 1 will be described. The dot points 1 to 12 in FIG. 10 referred to in the description of the processing flow are assumed to indicate all the measured dot points included in the conveyance path data.

[0047] The control device 20 acquires each model information, that is, galvanometer scanner model information, conveyance device model information, measurement system model information, and processing target model information.

[0048] [Step S101] The control device 20 generates a welding program or reads in a welding program created externally. By generating the welding program, the control device 20 acquires the position data of the welding dot points and / or the dot path data of the welding dot points.

[0049] [Step S102] The control device 20 generates an OCT measurement program. The OCT measurement program is a program for measuring measurement points on a workpiece, such as welded points. By generating the OCT measurement program, the control device 20 obtains position data of the measurement points and / or point path data of the measurement points. The position data of the measurement points is, for example, coordinate data indicating the center position of the measurement points. The point path data of the measurement points is, for example, indicated by a plurality of coordinate data on the point path. The position data of the measurement points and the point path data of the measurement points may be the same as the position data of the welded points and the point path data of the welded points.

[0050] Furthermore, the generation of the OCT measurement program obtains information regarding the measurement range for measuring the measurement points. The information regarding the measurement range includes the detection range and distance data corresponding to each measurement point. The distance data includes the shortest workpiece distance, the longest extension distance, and the longest measurement point distance along the path of each measurement point. To simplify calculations for each measurement point, the shortest workpiece distance in the distance data may be replaced with the workpiece distance at the center position of the measurement point, and the longest measurement point distance in the distance data may be replaced with the measurement point distance at the center position of the measurement point.

[0051] In particular, the control device 20 pre-sets the detection range. For example, if the theoretical detection range determined according to the individual performance (i.e., wavelength resolution) of the line sensor 326 is 0 to 12 mm (i.e., width 12 mm), the detection range used in actual measurement is set to 1 to 11 mm (i.e., width 10 mm).

[0052] The control device 20 stores the data for each measurement point acquired by generating the OCT measurement program in the buffer unit 204.

[0053] [Step S103] The control device 20 acquires distance information for the dotted point 1. That is, the control device 20 acquires the shortest workpiece distance (500 mm) and the longest measurement point distance (506 mm) of the dotted point 1 from the buffer unit 204 (see Figure 10).

[0054] (Measurement of dot point 1) [Step S104] The control device 20 sets the measurement range. Specifically, the control device 20 sets the measurement range adjustment value to the shortest workpiece distance (500 mm) of dot point 1. Since the detection range is 1 to 11 mm (i.e., width 10 mm), the measurement range starting from the measurement range adjustment value is set to 500 mm to 510 mm.

[0055] [Step S105] The control device 20 transmits a measurement range adjustment value to the measurement light source 32. The measurement light source 32 adjusts the reference arm 324 based on the measurement range adjustment value. Specifically, the measurement light source 32 adjusts the reference arm 324 so that the reference optical path length is equal to the measurement range adjustment value.

[0056] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value (i.e., measurement distance) related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0057] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 2 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0058] (Measurement of dot point 2) [Step S108] The control device 20 acquires distance information for dot point 2. That is, the control device 20 acquires the shortest workpiece distance (498 mm) and the longest measurement point distance (503 mm) of dot point 2 from the buffer unit 204 (see Figure 10).

[0059] [Step S109] The determination unit 203 determines whether or not to perform optical path length adjustment. Specifically, when measuring dot point 1, the reference optical path length is set to 500 mm. That is, the current measurement range is 500 mm to 510 mm. The distance from the shortest workpiece distance to the longest measurement point of dot point 2 is 498 mm to 503 mm, which is not included in the current measurement range. Therefore, dot point 2 cannot be measured in the current measurement range, so the determination unit 203 determines to perform optical path length adjustment (Step S109: Yes).

[0060] Alternatively, the determination unit 203 may determine whether or not to perform optical path length adjustment based on a comparison between the measured optical path length calculated from the command value (i.e., distance information indicating the shortest workpiece distance to the longest measurement point distance of dot point 2) and the reference optical path length calculated from the command value. The command value may be indicated by a position recorded in the OCT measurement program or by the target position of movement transmitted to the motor.

[0061] Alternatively, the determination unit 203 may determine whether or not to perform optical path length adjustment based on a comparison between the processing beam optical path length calculated from the position feedback value and the reference optical path length calculated from the position feedback value. The position feedback value is indicated by the actual position acquired by the motor's sensor (encoder).

[0062] Command values ​​and position feedback values ​​may be substituted for each other as they represent the same distance or position. Measurement optical path length and processing beam optical path length may, in principle, be treated as representing the same length. However, when measuring a position offset from the processing laser by the measurement light, the measurement optical path length and processing beam optical path length will not coincide.

[0063] In other words, the determination unit 203 may calculate the measurement optical path length or the processing beam optical path length from the command value or the position feedback value, calculate the reference optical path length in the measurement range adjustment mechanism from the command value or the position feedback value, and determine whether or not to perform the optical path length adjustment by comparing the measurement optical path length or the processing beam optical path length with the reference optical path length.

[0064] Alternatively, the determination unit 203 may obtain the measured optical path length or the processing beam optical path length and the reference optical path length from the buffer unit 204, and determine whether or not to perform optical path length adjustment by comparing these values.

[0065] Furthermore, the determination unit 203 may determine whether or not to perform optical path length adjustment based on whether or not the difference between the measured optical path length and the reference optical path length is within the measurement range of the measurement system.

[0066] [Step S110] The determination unit 203 transmits an execution command signal "1" to the measurement light source 32, causing the reference arm to perform optical path length adjustment.

[0067] [Step S111] The control device 20 resets the measurement range. Specifically, the control device 20 sets the measurement range adjustment value to the shortest workpiece distance (498 mm) of the dot point 2. At this time, since the detection range is 1 to 11 mm (i.e., width 10 mm), the measurement range starting from the measurement range adjustment value is 498 mm to 508 mm.

[0068] [Step S112] The control device 20 transmits the measurement range adjustment value to the measurement light source 32.

[0069] [Step S105] The measuring light source 32 adjusts the reference arm 324 based on the measurement range adjustment value. Specifically, the measuring light source 32 adjusts the reference arm 324 so that the reference optical path length is equal to the measurement range adjustment value (498 mm).

[0070] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0071] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 3 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0072] (Measurement of dot point 3) [Steps S108 to S112] Similarly, steps S108 to S112 are performed for dot point 3. Since the shortest workpiece distance to the longest measurement point distance for dot point 3 is 496 mm to 500 mm, dot point 3 cannot be measured within the measurement range (498 mm to 508 mm) used when measuring dot point 2. Therefore, it is determined that optical path length adjustment should be performed (Step S109: Yes), and the measurement range adjustment value is set to the shortest workpiece distance for dot point 3 (496 mm). The control device 20 transmits the measurement range adjustment value (496 mm) to the measurement light source 32.

[0073] [Step S105] The measuring light source 32 adjusts the reference arm 324 based on the measurement range adjustment value. Specifically, the measuring light source 32 adjusts the reference arm 324 so that the reference optical path length is equal to the measurement range adjustment value (496 mm).

[0074] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0075] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 4 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0076] (Measurement of dot point 4) [Steps S108 to S112] Similarly, steps S108 to S112 are performed for dot point 4. Since the shortest workpiece distance to the longest measurement point distance for dot point 4 is 505 mm to 510 mm, dot point 4 cannot be measured within the measurement range (496 mm to 506 mm) used when measuring dot point 3. Therefore, it is determined that optical path length adjustment should be performed (Step S109: Yes), and the measurement range adjustment value is set to the shortest workpiece distance for dot point 4 (505 mm). The control device 20 transmits the measurement range adjustment value (505 mm) to the measurement light source 32.

[0077] [Step S105] The measuring light source 32 adjusts the reference arm 324 based on the measurement range adjustment value. Specifically, the measuring light source 32 adjusts the reference arm 324 so that the reference optical path length is equal to the measurement range adjustment value (505 mm).

[0078] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0079] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 5 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0080] (Measurement of dot point 5) [Step S108] The control device 20 acquires distance information for dot point 5. That is, the control device 20 acquires the shortest workpiece distance (506 mm) and the longest measurement point distance (512 mm) of dot point 5 from the buffer unit 204 (see Figure 10).

[0081] [Step S109] The determination unit 203 determines whether or not to perform optical path length adjustment. Specifically, when measuring dot point 4, the reference optical path length is set to 505 mm. That is, the current measurement range is 505 mm to 515 mm. The distance from the shortest workpiece distance to the longest measurement point of dot point 5 is 506 mm to 512 mm, which is included in the current measurement range. Therefore, since dot point 5 can be measured within the current measurement range, the determination unit 203 determines that optical path length adjustment is not to be performed (Step S109: No).

[0082] [Step S113] The determination unit 203 transmits a signal "0" to the measurement light source 32 indicating that it will not perform optical path length adjustment on the reference arm. Next, the process proceeds to step S106.

[0083] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0084] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 6 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0085] (Measurement of dots 6-12) Similarly, measurement processing is performed for dots 6-12. As shown in Figure 10, optical path length adjustment is performed before the measurements of dots 7, 10, 11 and 12 are carried out.

[0086] [Step S107] In step S106 for dot point 12, after the measurement value of dot point 12 is obtained, the control device 20 determines whether the measurement process has been completed for all dot points. Since the measurement process for all dot points has been completed (Step S107: Yes), the process ends.

[0087] In the processing flow for dots 1 to 12 described above, optical path length adjustment is performed when measuring dots 1 to 4, dots 7, and dots 10 to 12, but not when measuring dots 5, 6, 8, and 9. In other words, the reference arm is adjusted a total of 8 times. Therefore, the cycle time for optical path length adjustment is shortened, and the overall processing time can be reduced.

[0088] In the first control example described above, the measurement range adjustment value for at least two weld points included in the transport path was calculated based on the shortest workpiece distance and the longest measurement point distance for each weld point. Here, if the presence of a weld bead after welding is considered, the measurement range adjustment value for at least two weld points included in the transport path may be calculated based on the sum of the shortest workpiece distance and the negative minimum measurement distance (i.e., the maximum bead height) for each weld point, and the longest measurement point distance.

[0089] The laser processing apparatus 1 of this embodiment, as described above in the first control example, provides the following effects.

[0090] The laser processing apparatus 1 of this embodiment, according to the first control example, includes a processing head 12 including at least one laser beam deflection mechanism 13 for irradiating a workpiece 40 with a laser, a beam control unit 201 for controlling the laser beam deflection mechanism 13, at least one measurement light deflection mechanism 34 optically coupled to the processing head 12, a measurement light control unit 202 for controlling the measurement light deflection mechanism 34, an optical measurement unit 30 for obtaining measurement values ​​related to measurement points on the workpiece 40 using measurement light, a measurement range adjustment mechanism 324 for performing optical path length adjustment to adjust the reference optical path length or the measurement optical path length, and a determination unit 203 for determining whether or not to perform optical path length adjustment before the optical measurement unit 30 obtains measurement values. The measurement range adjustment mechanism 324 performs optical path length adjustment when it receives a signal for optical path length adjustment from the determination unit 203. This reduces the number of reference arm adjustments and therefore shortens the overall processing time.

[0091] Furthermore, the laser processing apparatus 1 includes a transport device 70 for the processing head 12 and a support device M for the workpiece 40. This allows the processing range of the processing head to be expanded.

[0092] Furthermore, before the optical measurement unit 30 obtains a measurement value, the determination unit 203 compares the distance information of the target point to be measured with the current reference optical path length in the measurement range adjustment mechanism 324 to determine whether or not to perform optical path length adjustment. This reduces the number of reference arm adjustments, and therefore shortens the overall processing time.

[0093] Furthermore, the laser processing apparatus 1 is equipped with a buffer unit 204 that stores distance information of the target point to be measured. Before the optical measurement unit 30 obtains the measurement value, the determination unit 203 obtains the distance information of the target point to be measured from the buffer unit 204 and compares the distance information of the target point to the current reference optical path length in the measurement range adjustment mechanism 324 to determine whether or not to perform optical path length adjustment. As a result, since the values ​​to be used are stored in the buffer unit 204, which can be read immediately, communication with other devices immediately before the command is issued is unnecessary, computational resources can be effectively reduced, and the time required for the entire processing can be shortened.

[0094] Furthermore, the elongation distance may be fixed in a given welding program. This effectively reduces the computational resources required for elongation distance, thereby shortening the overall processing time.

[0095] Furthermore, the determination unit 203 determines whether or not to perform the optical path length adjustment based on whether the range from the shortest workpiece distance to the longest measurement point distance of the measurement target point is within the measurement range of the measurement system. This reduces the number of reference arm adjustments, and therefore shortens the overall processing time.

[0096] Furthermore, the measurement range adjustment mechanism 324 adjusts the optical path length by setting the reference optical path length to the value of the shortest workpiece distance to the point to be measured. This reduces the number of reference arm adjustments, and therefore shortens the overall processing time.

[0097] In the first control example described above, in step S111, the measurement range adjustment value was set to the shortest workpiece distance of the measurement point. Alternatively, the measurement range adjustment value may be set to any value related to the distance information of the measurement point, such as the longest measurement point distance. For example, the measurement range adjustment value may be set to any value that falls between the shortest workpiece distance and the longest measurement point distance. The following second control example shows an example in which the measurement range adjustment value is set so that the median of the measurement range is equal to the median of the shortest workpiece distance to the longest measurement point distance of the measurement point 3.

[0098] <Second Control Example> (Processing Flow of Laser Processing Equipment) Figure 11 shows the number of adjustments to the reference arm related to the second control example. The method for setting the measurement range in the second control example is different from that of the first control example. The differences from the first control example will be explained using the flowchart in Figure 9.

[0099] Steps S101 to S103 are the same as the steps in the first control example.

[0100] (Measurement of dot point 1) [Step S104] The control device 20 sets the measurement range. Specifically, the control device 20 sets the median of the measurement range to be equal to the median of the shortest work distance to the longest measurement point distance of dot point 1. The detection range is 1 to 11 mm (i.e., width 10 mm), and the median of the shortest work distance to the longest measurement point distance of dot point 1 is 503 mm, so the measurement range having a median of 503 mm is set to 498 mm to 508 mm. Here, the measurement range adjustment value, which is the starting point of the measurement range, is 498 mm.

[0101] [Steps S105 to S107] Steps S105 to S107 are performed for dot point 1, similar to the first control example.

[0102] (Measurement of point 2) [Step S108] Distance information of point 2 is acquired, similar to the first control example.

[0103] [Step S109] The determination unit 203 determines whether or not to perform optical path length adjustment. Specifically, when measuring dot point 1, the reference optical path length is set to 498 mm. That is, the current measurement range is 498 mm to 508 mm. The distance from the shortest workpiece distance to the longest measurement point of dot point 2 is 498 mm to 503 mm, which is included in the current measurement range. Therefore, since dot point 2 can be measured within the current measurement range, the determination unit 203 determines that optical path length adjustment is not to be performed (Step S109: No).

[0104] [Step S113] The determination unit 203 transmits a signal "0" to the measurement light source 32 indicating that it will not perform optical path length adjustment on the reference arm. Next, the process proceeds to step S106.

[0105] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0106] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 3 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0107] (Measurement of dot point 3) [Step S108] The control device 20 acquires distance information for dot point 3. That is, the control device 20 acquires the shortest workpiece distance (496 mm) and the longest measurement point distance (500 mm) of dot point 3 from the buffer unit 204 (see Figure 11).

[0108] [Step S109] The determination unit 203 determines whether or not to perform optical path length adjustment. Specifically, when measuring dot point 2, the reference optical path length is set to 498 mm. That is, the current measurement range is 498 mm to 508 mm. The distance from the shortest workpiece distance to the longest measurement point of dot point 3 is 496 mm to 500 mm, which is not included in the current measurement range. Therefore, dot point 3 cannot be measured in the current measurement range, so the determination unit 203 determines to perform optical path length adjustment (Step S109: Yes).

[0109] [Step S110] The determination unit 203 transmits an execution command signal "1" to the measurement light source 32, causing the reference arm to perform optical path length adjustment.

[0110] [Step S111] The control device 20 resets the measurement range. Specifically, the control device 20 sets the median of the measurement range to be equal to the median of the distance from the shortest workpiece distance to the longest measurement point at the dotted point 3. The detection range is 1 to 11 mm (i.e., width 10 mm), and the median of the distance from the shortest workpiece distance to the longest measurement point at the dotted point 3 is 498 mm. Therefore, the measurement range with a median of 498 mm is 493 mm to 503 mm. Accordingly, the measurement range adjustment value is set to 493 mm.

[0111] [Step S112] The control device 20 transmits the measurement range adjustment value to the measurement light source 32.

[0112] [Step S105] The measuring light source 32 adjusts the reference arm 324 based on the measurement range adjustment value. Specifically, the measuring light source 32 adjusts the reference arm 324 so that the reference optical path length is equal to the measurement range adjustment value (493 mm).

[0113] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0114] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 4 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0115] (Measurement of hit point 4) [Steps S108 to S110] Steps S108 to S110 for hit point 4 are performed in the same manner as steps S108 to S110 for hit point 3.

[0116] [Step S111] The control device 20 resets the measurement range. Specifically, the control device 20 sets the median of the measurement range to be equal to the median of the shortest workpiece distance to the longest measurement point distance of the dot point 4. Here, the median of the shortest workpiece distance to the longest measurement point distance (505 mm to 510 mm) of the dot point 4 is 507.5 mm. Since this median has decimal places, the median of the measurement range is set to the rounded value of this median (508 mm). For simplicity, the value is calculated by rounding, but a more precise value may be set. The resolution of this distance depends on the distance resolution of the stepping motor, and is generally about 0.01 mm. Also, although the process is shown using the median, this is not limited to this, and for example, the position may be offset by an arbitrary set value.

[0117] The detection range is 1 to 11 mm (i.e., a width of 10 mm), and the median value between the shortest workpiece distance and the longest measurement point distance for dot point 4 is 508 mm. Therefore, the measurement range with a median of 508 mm is 503 mm to 513 mm. Accordingly, the measurement range adjustment value is set to 503 mm.

[0118] [Step S112] The control device 20 transmits the measurement range adjustment value to the measurement light source 32.

[0119] [Step S105] The measuring light source 32 adjusts the reference arm 324 based on the measurement range adjustment value. Specifically, the measuring light source 32 adjusts the reference arm 324 so that the reference optical path length is equal to the measurement range adjustment value (503 mm).

[0120] [Step S106] The measurement system 30 uses measuring light to obtain a measurement value related to the keyhole depth that occurs near the processed area of ​​the workpiece during welding.

[0121] [Step S107] The control device 20 determines whether the measurement process has been completed for all dots. Since the processing for dots 5 to 12 has not been completed (Step S107: No), the process proceeds to step S108.

[0122] (Measurement of dots 5 to 12) Similarly, measurement processing is performed for dots 5 to 12. As shown in Figure 11, optical path length adjustment is performed before the measurements of dots 10 and 12 are carried out.

[0123] [Step S107] In step S106 for dot point 12, after the measurement value of dot point 12 is obtained, the control device 20 determines whether the measurement process has been completed for all dot points. Since the measurement process for all dot points has been completed (Step S107: Yes), the process ends.

[0124] In the processing flow for dots 1 to 12 described above, optical path length adjustment is performed when measuring dots 1, 3 to 4, 10, and 12, but not when measuring dots 2, 5 to 9, and 11. In other words, the reference arm is adjusted a total of 5 times. Consequently, the cycle time for optical path length adjustment is shortened, and the overall processing time can be reduced.

[0125] Figure 12 shows how the reference arm is adjusted by the processing of the second control example. As shown in Figure 12, measurements are performed in the order of left, center, and right. For the center measurement, the measurement can be performed using the measurement range set in the left measurement (OK), so no adjustment of the reference arm is necessary. For the right measurement, the measurement cannot be performed using the measurement range set in the center measurement (NG), so the reference arm is adjusted. In Figure 7, the reference arm was adjusted for all dot measurements, but in the example shown in Figure 12, no adjustment of the reference arm is necessary for the measurement of the center dot.

[0126] The laser processing apparatus 1 of this embodiment, as described above in the second control example, provides the following effects.

[0127] In the laser processing apparatus 1 of this embodiment, which relates to the second control example, the measurement range adjustment mechanism 324 further adjusts the optical path length by setting the reference optical path length to the median value of the shortest workpiece distance and the longest measurement point distance of the target point. This reduces the number of reference arm adjustments and, therefore, shortens the overall processing time.

[0128] <Third Control Example> (Processing Flow of Motion Planning Device) Referring to Figures 13 and 14, the processing flow executed by the motion planning device 80 that creates the motion plan for the laser processing device 1 will be described. The dots 1 to 12 in Figure 14 referred to in the description of the processing flow represent all the measurement dots included in the transport path data.

[0129] The acquisition unit 801 acquires information on each model, namely the galvanometer scanner model, the transport device model, the measurement system model, and the model to be processed.

[0130] [Step S201] The control device 20 generates a welding program. Upon generation of the welding program, the acquisition unit 801 acquires position data of the welding points and / or welding point path data.

[0131] If the galvanometer scanner's operation plan is pre-set by the operator, the welding point position data and / or welding point path data may be generated based on the constraints imposed by the galvanometer scanner's operation plan.

[0132] If the operation plan of the conveying device is set in advance by the operator, the position data of the welding point and / or the welding point path data may be generated based on the constraints of the operation plan of the conveying device.

[0133] [Step S202] The motion planning device 80 generates an OCT measurement program. The OCT measurement program is a program for measuring welded points. By generating the OCT measurement program, the acquisition unit 801 acquires position data of the measured points and / or point path data of the measured points. The position data of the measured points is, for example, coordinate data indicating the center position of the measured points. The point path data of the measured points is, for example, indicated by a plurality of coordinate data on the point path. The position data of the measured points and the point path data of the measured points may be the same as the position data of the welded points and the point path data of the welded points.

[0134] Furthermore, the generation of the OCT measurement program obtains information regarding the measurement range for measuring the measurement points. The information regarding the measurement range includes the detection range and distance data corresponding to each measurement point. The distance data includes the shortest workpiece distance, the longest extension distance, and the longest measurement point distance along the path of each measurement point. To simplify calculations for each measurement point, the shortest workpiece distance in the distance data may be replaced with the workpiece distance at the center position of the measurement point, and the longest measurement point distance in the distance data may be replaced with the measurement point distance at the center position of the measurement point.

[0135] In particular, the acquisition unit 801 pre-sets the detection range. For example, if the theoretical detection range determined according to the wavelength resolution of the line sensor 326 is 0 to 12 mm (i.e., a width of 12 mm), the detection range used in actual measurement is set to 1 to 11 mm (i.e., a width of 10 mm).

[0136] The acquisition unit 801 acquires information on all dots included in the transport path data. For each dot, the acquisition unit 801 acquires the shortest workpiece distance, the longest elongation distance, and the longest measurement point distance. Figure 14 shows the distances acquired for each of dots 1 to 12.

[0137] (Processing of point 1) At the end of step S202, the acquisition unit 801 acquires the shortest workpiece distance (500 mm) and the longest measurement point distance (506 mm) of point 1, and the processing of step S202 is completed.

[0138] (Processing of point 2) [Step S203] The motion planning device 80 determines whether processing has been completed for all points. Since processing for points 2 to 12 has not been completed (Step S203: No), the device proceeds to step S204.

[0139] [Step S204] The acquisition unit 801 acquires the shortest workpiece distance (498 mm) and the longest measurement point distance (503 mm) of the dotting point 2.

[0140] [Step S205] The motion planning device 80 determines whether the dot 2 can be measured in the current group. Specifically, it determines whether the previous dot 1 and the current dot 2 can be measured within the same measurement range.

[0141] The detection range is 1 to 11 mm (i.e., a width of 10 mm). Therefore, if the measurement range adjustment value is set to the shortest workpiece distance of dot point 2 (498 mm), measurement becomes possible from 498 mm to 508 mm. This 498 mm to 508 mm range includes the shortest workpiece distance to the longest measurement point distance of dot point 1 (500 mm to 506 mm). Thus, by setting the measurement range adjustment value to a predetermined value (for example, 498 mm), dot point 1 and dot point 2 can be measured within the same measurement range without adjusting the reference arm. Since dot point 2 can be measured within the same measurement range as dot point 1, it is determined that dot point 2 can be measured in the same group as dot point 1, i.e., in the current group (step S205: Yes), and the process proceeds to step S206.

[0142] [Step S206] The motion planning device 80 adds point 2 to the current group. Specifically, the motion planning device 80 adds point 2 to the current group 1, which includes point 1. The process then proceeds to step S203.

[0143] (Processing of point 3) [Step S203] The motion planning device 80 determines whether processing has been completed for all points. Since processing for points 3 to 12 has not been completed (Step S203: No), the device proceeds to step S204.

[0144] [Step S204] The acquisition unit 801 acquires the shortest workpiece distance (496 mm) and the longest measurement point distance (500 mm) of the dotting point 3.

[0145] [Step S205] The motion planning device 80 determines whether dot point 3 can be measured in the current group. Specifically, it determines whether dot points 1 and 2 included in the current group and the current dot point 3 can be measured within the same measurement range.

[0146] The detection range is 1 to 11 mm (i.e., a width of 10 mm). Therefore, if the measurement range adjustment value is set to the shortest workpiece distance of dot point 3 (496 mm), measurement becomes possible from 496 mm to 506 mm. This 496 mm to 506 mm range includes the shortest workpiece distance to the longest measurement point distance of dot point 1 (500 mm to 506 mm) and the shortest workpiece distance to the longest measurement point distance of dot point 2 (498 mm to 503 mm). Thus, by setting the measurement range adjustment value to a predetermined value (for example, 496 mm), dot points 1 to 3 can be measured within the same measurement range without adjusting the reference arm. Since dot point 3 can be measured within the same measurement range as dot points 1 to 2, it is determined that dot point 3 can be measured in the same group as dot points 1 to 2, i.e., in the current group (step S205: Yes), and the process proceeds to step S206.

[0147] [Step S206] The motion planning device 80 adds point 3 to the current group. Specifically, the motion planning device 80 adds point 3 to the current group 1, which includes points 1 and 2. The process then proceeds to step S203.

[0148] (Processing of point 4) [Step S203] The motion planning device 80 determines whether processing has been completed for all points. Since processing for points 4 to 12 has not been completed (Step S203: No), the device proceeds to step S204.

[0149] [Step S204] The acquisition unit 801 acquires the shortest workpiece distance (505 mm) and the longest measurement point distance (510 mm) of the dotting point 4.

[0150] [Step S205] The motion planning device 80 determines whether dot point 4 can be measured in the current group. Specifically, it determines whether dot points 1 to 3 included in the current group and the current dot point 4 can be measured within the same measurement range.

[0151] Since the detection range is 1 to 11 mm (i.e., a width of 10 mm), no matter what value the measurement range adjustment value is set to, it is not possible to include dots 1 to 3, where the minimum value of the shortest workpiece distance to the maximum value of the longest measurement point distance is 496 mm to 506 mm, and dot 4, where the shortest workpiece distance to the longest measurement point distance is 505 mm to 510 mm, within any measurement range of 10 mm. Therefore, it is determined that dots 1 to 3 and dot 4 cannot be measured within the same measurement range.

[0152] Therefore, in order to measure point 4, it is necessary to adjust the reference arm, and it is not possible to measure point 4 within the same measurement range as the current group 1 (step S205: No). Proceed to step S207.

[0153] [Step S207] The motion planning device 80 saves the current group 1. The calculation unit 802 sets the measurement range adjustment value for measuring dots 1 to dots 3 to 496 mm, which is the minimum of the shortest work distances between dots 1 to dots 3 included in the current group 1. This completes the processing for the current group 1.

[0154] Next, the motion planning device 80 creates a new group 2. The motion planning device 80 adds point 4 to group 2. Then, it returns to step S203.

[0155] (Processing of dots 5 to 12) Similarly, processing for dots 5 to 9 is performed, and dots 5 to 9 are added to the current group 2, which includes dot 4. Also, in processing dot 10, it is determined that dot 10 cannot be measured within the same measurement range as dots 4 to 9 included in group 2 (step S205: no), so dot 10 is added to a new group 3. Dots 11 and 12 are added to group 3.

[0156] [Step S203: After dotting point 12] The motion planning device 80 determines whether processing has been completed for all dotting points. After it is determined that processing has been completed for all dotting points 1 to 12 (Step S203: Yes), the device proceeds to step S208.

[0157] [Step S208] The optimization unit 803 optimizes the operation of the entire laser ranging system, i.e., the system operation plan, based on the measurement range adjustment value. This optimizes the operation plan of the galvanometer scanner, the measurement system, and the transport device.

[0158] [Step S209] The motion planning device 80 transmits at least one calculated measurement range adjustment value to the control device 20. The buffer unit 204 stores at least one measurement range adjustment value.

[0159] [Step S210] Immediately before performing the measurement, the control device 20 transmits the measurement range adjustment value stored in the buffer unit 204 to the measurement light source 32. After the above processing, the processing flow ends.

[0160] In the processing flow for dots 1 to 12 described above, dots 1 to 12 were classified into groups 1 to 3. The measurement range adjustment value for group 1 was set to 496 mm, for group 2 to 504 mm, and for group 3 to 496 mm. In measuring dots within each group, it is no longer necessary to change the measurement range adjustment value, thus eliminating the need to adjust the reference arm. In other words, the objective function of the cycle time related to the measurement range adjustment value is minimized, and each motion plan is created based on this, thus optimizing the system motion plan.

[0161] Figure 15 shows how the reference arm is adjusted by the processing of the third control example. As shown in Figure 15, measurements are performed in the order of left, center, and right. For the center and right measurements, the measurement can be performed using the measurement range set in the left measurement (OK), so adjustment of the reference arm is unnecessary. In Figure 7, the reference arm was adjusted when measurements were performed in the order of left, center, and right, but in the example shown in Figure 15, adjustment of the reference arm is unnecessary for the measurement of the three dots on the left, center, and right.

[0162] In the third control example described above, the measurement range adjustment value for at least two weld points included in the transport path was calculated based on the shortest workpiece distance and the longest measurement point distance for each weld point. Here, if the presence of a weld bead after welding is considered, the measurement range adjustment value for at least two weld points included in the transport path may be calculated based on the sum of the shortest workpiece distance and the negative minimum measurement distance (i.e., the maximum bead height) for each weld point, and the longest measurement point distance.

[0163] As described above, in the third control example, the system operation plan was optimized using the number of adjustments or adjustment time of the reference arm as an evaluation item. The measurement order or the transport device path may be optionally changed during the operation plan.

[0164] As described above, the motion planning device 80 calculates the measurement range adjustment value and transmits it to the control device 20. Alternatively, the determination unit 203 may execute the processing of the motion planning device 80 and calculate the measurement range adjustment value.

[0165] Furthermore, the scoring order may be selected by considering evaluation criteria such as the movement speed of the conveying device, the energy consumption of the conveying device, and the cost of moving the conveying device. Examples of evaluation criteria that may be considered will be described later.

[0166] <Evaluation Items for Operation Plan> In the third control example, an example was shown in which the number of reference arm adjustments is reduced by setting the measurement range adjustment value in order to shorten the cycle time. The operation plan of the entire laser processing apparatus may be optimized by adding evaluation items as shown in Figure 16 to the third control example.

[0167] The constraints in Figure 16A are conditions related to the constraints on the operation of the system. The constraints are conditions for determining whether the set operation plan is OK or NG.

[0168] For example, regarding the evaluation item "interference with fixtures," paths where the processing laser is determined to hit the fixture are excluded, even if they result in a shorter cycle time.

[0169] The objective function in Figure 16B represents the conditions for numerically evaluating the system's operation plan, such as by assigning scores. Each item shown in Figure 16B is evaluated comprehensively based on its magnitude and other factors.

[0170] For example, in the third control example, the "calibration optimization (measurement grouping)" of the "cycle time" in the objective function was evaluated. In any control example, the "machining order of machining points" in the "cycle time" in the objective function may be further evaluated.

[0171] Furthermore, each objective function may be evaluated by normalizing or weighting it.

[0172] The laser processing apparatus 1 of this embodiment, according to the third control example described above, provides the following effects.

[0173] The laser processing apparatus 1 of this embodiment, according to the third control example, further comprises a motion planning device 80. The determination unit 203 or the motion planning device 80 calculates the measurement optical path length or processing beam optical path length for multiple measurements within a pre-generated measurement program, calculates the measurement range adjustment value for the measurement range adjustment mechanism 324 for each measurement that reduces the number of optical path length adjustments performed through the multiple measurements within the measurement program, the determination unit 203 transmits the calculated measurement range adjustment value to the measurement range adjustment mechanism 324, and the measurement range adjustment mechanism 324 adjusts the reference optical path length based on the received measurement range adjustment value. This reduces the number of reference arm adjustments and, therefore, shortens the overall processing time.

[0174] <Computer Configuration> As shown in Figure 17, the computer 90 according to the embodiment of this disclosure comprises a processor 91, main memory 92, storage 93, and interface 94. The control device 20 or motion planning device 80 in the laser processing apparatus 1 described above is implemented in the computer 90.

[0175] The operation instructions for each of the above-mentioned processing units are stored in storage 93 in the form of a program. The processor 91 reads the program from storage 93, expands it into main memory 92, and executes the above processing according to the program. If the program is distributed to computer 90 via a communication line or interface 94, the processor 91 may also expand the distributed program into main memory 92 and execute the above processing.

[0176] The program may be intended to implement a part of the functions that the processor 91 is to perform. For example, the program may perform its functions in combination with other programs already stored in the storage 93, or in combination with other programs implemented in other devices.

[0177] Storage 93 can be an HDD, SSD, magnetic disk, magneto-optical disk, CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory), semiconductor memory, etc. Storage 93 may also be a tangible storage medium that is not temporary.

[0178] <Other Embodiments> Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of the present disclosure or from the spirit of the present disclosure derived from the claims and their equivalents. Furthermore, these embodiments can be implemented in combination. For example, the order of operations and processes in the embodiments described above are shown as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

[0179] (Configuration of the measurement system) As an example of the application of this disclosure, the optical coherence interferometer unit of the measurement system may be replaced with other optical measurement units, and the measurement range adjustment mechanism may be replaced with other measurement range adjustment mechanisms. For example, the measurement system 30 may have a configuration in which the optical coherence interferometer unit is replaced with a camera, a photodiode, or a lens unit without a light receiver. In this case, the measurement system 30 has a configuration in which the measurement range adjustment mechanism is replaced with a focus lens adjustment mechanism.

[0180] Furthermore, as shown in Figure 18, the measurement system 30 may have a configuration in which at least one of a camera, a photodiode, and a lens unit without a light receiver is continuously attached to the OCT unit. The connection order in this case is not particularly limited. In addition, the operation plan may include optimizing the detection range in each unit.

[0181] (Execution body of the process) In the above embodiment, some or all of the processing performed by the control device 20 or the operation planning device 80 may be performed by other devices. Each device in each embodiment may consist of multiple devices. Each device in each embodiment may be implemented using cloud computing.

[0182] (Examples of various embodiments) The following additional information is disclosed with respect to the above embodiments.

[0183] (Note 1) A laser processing apparatus (1) comprising: a processing head (12) including at least one laser beam deflection mechanism (13) for irradiating a workpiece (40) with a laser; a beam control unit (201) for controlling the laser beam deflection mechanism (13); at least one measurement light deflection mechanism (34) optically coupled to the processing head (12); a measurement light control unit (202) for controlling the measurement light deflection mechanism (34); an optical measurement unit (30) for obtaining measurement values ​​for measurement points on the workpiece (40) using measurement light; a measurement range adjustment mechanism (324) for performing optical path length adjustment to adjust the reference optical path length or the measurement optical path length; and a determination unit (203) for determining whether or not to perform the optical path length adjustment before the optical measurement unit (30) obtains the measurement value, wherein the measurement range adjustment mechanism (324) performs the optical path length adjustment when it receives a signal for optical path length adjustment from the determination unit (203).

[0184] (Note 2) The laser processing apparatus (1) described above further comprises a laser light source (11) for generating a processing beam.

[0185] (Note 3) The laser processing apparatus (1) described above comprises a transport device (70) for the processing head (12) and a support device (M) for the workpiece (40).

[0186] (Note 4) In the laser processing apparatus (1) described above, before the optical measurement unit (30) obtains the measurement value, the determination unit (203) compares the distance information of the measurement target point with the current reference optical path length in the measurement range adjustment mechanism (324) to determine whether or not to perform the optical path length adjustment.

[0187] (Note 5) The laser processing apparatus (1) described above includes a buffer unit (204) that stores distance information of the point to be measured. Before the optical measurement unit (30) obtains the measurement value, the determination unit (203) obtains the distance information of the point to be measured from the buffer unit (204), and determines whether or not to perform the optical path length adjustment by comparing the distance information of the point to be measured with the current reference optical path length in the measurement range adjustment mechanism (324).

[0188] (Note 6) In the laser processing apparatus (1) described above, the extension distance is fixed in the predetermined welding program.

[0189] (Note 7) In the laser processing apparatus (1) described above, the extension distance is variable in a predetermined welding program.

[0190] (Note 8) In the laser processing apparatus (1) described above, the determination unit (203) determines whether or not to perform the optical path length adjustment based on whether or not the range from the shortest workpiece distance to the longest measurement point distance of the target point to be measured is within the measurement range of the measurement system.

[0191] (Note 9) In the laser processing apparatus (1) described above, the measurement range is based on the detection range of the measurement system (30) as a standalone unit, the temporal change in the distance to the object to be measured, and the temporal change in the measurement distance due to the processing effect on the object to be measured.

[0192] (Note 10) In the laser processing apparatus (1) described above, the measurement range adjustment mechanism (324) performs the optical path length adjustment by setting the reference optical path length to the value of the shortest workpiece distance of the point to be measured.

[0193] (Note 11) In the laser processing apparatus (1) described above, the measurement range adjustment mechanism (324) performs the optical path length adjustment by setting the reference optical path length to any value that falls within the range from the shortest workpiece distance to the longest measurement point distance of the target point.

[0194] (Note 12) The laser processing apparatus (1) described above includes a motion planning device (80), and the determination unit (203) or the motion planning device (80) calculates the measurement optical path length or processing beam optical path length for multiple measurements in a measurement program based on a pre-generated measurement program, calculates the measurement range adjustment value of the measurement range adjustment mechanism (324) for each measurement in which the number of optical path length adjustments performed decreases through the multiple measurements in the measurement program, the determination unit (203) transmits the calculated measurement range adjustment value to the measurement range adjustment mechanism (324), and the measurement range adjustment mechanism (324) adjusts the reference optical path length based on the received measurement range adjustment value.

[0195] (Note 13) In the laser processing apparatus (1) described above, the optical measuring unit (30) includes at least one optical component that does not have an OCT sensor, a camera, a photodiode, or a light receiver.

[0196] (Note 14) In the laser processing apparatus (1) described above, the transport device (70) is a robot, a single-axis machining center, or a multi-axis machining center.

[0197] 1 Laser processing device 10 Galvanometer scanner 11 Laser light source 12 Processing head 13 Laser light deflection mechanism 20 Control device 30 Measurement system, optical measurement unit 32 Measurement light source 33 Scanner 34 Measurement light deflection mechanism 35 Calculation unit 40 Workpiece 70 Transport device 80 Motion planning device 90 Computer 91 Processor 92 Main memory 93 Storage 94 Interface 201 Beam control unit 202 Measurement light control unit 203 Judgment unit 204 Buffer unit 321 Light-emitting diode 322 Beam splitter 323 Reference mirror 324 Reference arm, measurement range adjustment mechanism 325 Diffraction grating 326 Line sensor

Claims

1. A laser processing apparatus comprising: a processing head including at least one laser beam deflection mechanism for irradiating a workpiece with a laser; a beam control unit for controlling the laser beam deflection mechanism; at least one measurement light deflection mechanism optically coupled to the processing head; a measurement light control unit for controlling the measurement light deflection mechanism; an optical coherence interferometer unit for obtaining measurement values ​​related to measurement points on the workpiece using measurement light; a measurement range adjustment mechanism for performing optical path length adjustment to adjust a reference optical path length or a measurement optical path length; and a determination unit for determining whether or not to perform the optical path length adjustment before the optical coherence interferometer unit obtains the measurement value, wherein the measurement range adjustment mechanism performs the optical path length adjustment when it receives a signal for optical path length adjustment from the determination unit.

2. The laser processing apparatus according to claim 1, further comprising a laser light source for generating a processing beam.

3. The laser processing apparatus according to claim 1, comprising a transport device for the processing head and a support device for the workpiece.

4. The laser processing apparatus according to claim 1, wherein, before the optical coherence interferometer unit obtains the measurement value, the determination unit determines whether or not to perform the optical path length adjustment by comparing the distance information of the measurement target point with the current reference optical path length in the measurement range adjustment mechanism.

5. The laser processing apparatus according to claim 1, comprising a buffer unit that stores distance information of a target point to be measured, wherein, before the optical coherence interferometer unit obtains the measurement value, the determination unit obtains the distance information of the target point to be measured from the buffer unit, and determines whether or not to perform the optical path length adjustment by comparing the distance information of the target point to be measured with the current reference optical path length in the measurement range adjustment mechanism.

6. The laser processing apparatus according to claim 1, wherein the elongation distance is fixed in a predetermined welding program.

7. The laser processing apparatus according to claim 1, wherein the elongation distance is variable in a predetermined welding program.

8. The laser processing apparatus according to claim 1, wherein the determination unit determines whether or not to perform the optical path length adjustment based on whether or not the range from the shortest workpiece distance to the longest measurement point distance of the measurement target point is within the measurement range of the measurement system.

9. The laser processing apparatus according to claim 8, wherein the measurement range is based on the detection range of the measurement system as a standalone performance, the temporal change in distance to the object to be measured, and the temporal change in measurement distance due to the processing effect on the object to be measured.

10. The laser processing apparatus according to claim 1, wherein the measurement range adjustment mechanism performs the optical path length adjustment by setting the reference optical path length to the value of the shortest workpiece distance of the point to be measured.

11. The laser processing apparatus according to claim 1, wherein the measurement range adjustment mechanism performs the optical path length adjustment by setting the reference optical path length to any value included in the range from the shortest workpiece distance to the longest measurement point distance of the target point.

12. A laser processing apparatus according to claim 1, comprising a motion planning device, wherein the determination unit or the motion planning device calculates the measurement optical path length or processing beam optical path length for multiple measurements in a measurement program based on a pre-generated measurement program, calculates a measurement range adjustment value for the measurement range adjustment mechanism for each measurement in which the number of optical path length adjustments is reduced through the multiple measurements in the measurement program, the determination unit transmits the calculated measurement range adjustment value to the measurement range adjustment mechanism, and the measurement range adjustment mechanism adjusts the reference optical path length based on the received measurement range adjustment value.

13. The laser processing apparatus according to claim 3, wherein the transport device is a robot, a single-axis machining center, or a multi-axis machining center.

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