Control device, laser processing head, laser processing device, laser processing system, and laser processing method

Abstract

A control device (10) is characterized by being provided with: a data acquiring unit that acquires a reflected light irradiation position, which is an incident position at which a part of reflected light (RL) resulting from laser light (L) incident from a fiber end (1) of an optical fiber (7) being reflected by a workpiece (W) is incident on a photodetector (6-1), which is a reflected light sensor, and the amount of reflected light (RL) that is incident on the photodetector (6-1), which is the reflected light sensor; and a reflected light estimating unit that, on the basis of the reflected light irradiation position and the amount of reflected light (RL) incident on the photodetector (6-1), which is the reflected light sensor, estimates the amount of fiber reflected light, which is another part of the reflected light (RL) and that is reflected light (RL) incident on the fiber end (1).

Description

Control device, laser processing head, laser processing device, laser processing system, and laser processing method

[0001] The present disclosure relates to a control device for laser processing, which performs processing using laser light transmitted through an optical fiber, a laser processing head, a laser processing device, a laser processing system, and a laser processing method.

[0002] In laser processing devices that perform laser processing by irradiating a workpiece with laser light transmitted through an optical fiber, if the laser light reflected from the workpiece enters the fiber end of the optical fiber, it can damage the oscillator. For this reason, methods for detecting reflected light are being studied.

[0003] For example, Patent Document 1 discloses a technology in which laser light emitted from the end of a fiber is made incident on a bend mirror, the reflected light from the bend mirror is irradiated onto an object to be processed, the light reflected from the object to be processed that has passed through the bend mirror is made incident on an absorber, and the amount of scattered light from the absorber is detected by a light detection means.

[0004] Patent No. 5785740

[0005] However, with the above-mentioned conventional technology, although it is possible to detect the amount of light reflected from the workpiece, not all of the reflected light is incident on the fiber end, so there is a problem in that it is not possible to grasp the amount of reflected light incident on the fiber end.

[0006] The present disclosure has been made in view of the above, and aims to provide a control device that can grasp the amount of reflected light that is incident on a fiber end.

[0007] In order to solve the above-mentioned problems and achieve the object, the control device of the present disclosure is characterized by comprising: a data acquisition unit that acquires a reflected light irradiation position, which is the incident position where a portion of the reflected light that is reflected by the object to be processed and enters the reflected light sensor, and the amount of reflected light that enters the reflected light sensor; and a reflected light estimation unit that estimates the amount of fiber reflected light, which is the other portion of the reflected light that enters the fiber end, based on the reflected light irradiation position and the amount of reflected light that enters the reflected light sensor.

[0008] According to the present disclosure, it is possible to obtain an effect of determining the amount of reflected light incident on a fiber end.

[0009] FIG. 1 is a diagram showing an example of the configuration of a laser processing system according to a first embodiment. FIG. 2 is an explanatory diagram of laser processing when the processing state is good. FIG. 3 is an explanatory diagram of laser processing when a penetration-impaired state occurs. FIG. 4 is a diagram showing an example of the functional configuration of a control device according to a first embodiment. FIG. 5 is a flowchart for explaining an example of the operation of the control device according to the first embodiment. FIG. 6 is a diagram showing an example of the functional configuration of a control device according to a second embodiment. FIG. 7 is a diagram showing an example of a neural network used for machine learning in the second embodiment. FIG. 8 is a diagram showing an example of the configuration of a laser processing system according to a third embodiment. FIG. 9 is a diagram showing an example of the configuration of a computer system that realizes the control devices according to the first to third embodiments. FIG. 10 is a diagram showing dedicated hardware for realizing the functions of the control devices according to the first to third embodiments.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A control device, a laser processing head, a laser processing device, a laser processing system, and a laser processing method according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0011] 1 is a diagram showing an example of the configuration of a laser processing system 100 according to embodiment 1. The laser processing system 100 includes a control device 10 that controls the laser processing system 100, a laser processing head 20 that irradiates a processing laser beam L onto a workpiece W, an oscillator 8 that supplies the processing laser beam L to the laser processing head 20, and an optical fiber 7 that transmits the laser beam L emitted by the oscillator 8 to the laser processing head 20.

[0012] The laser processing system 100 performs laser processing such as cutting, welding, and laminating. The control device 10 and the laser processing head 20 are collectively referred to as the laser processing device. In the following description, the surface of a table (not shown) on which the workpiece W is placed is referred to as the xy plane, and the laser processing head 20 is positioned at a distance in the z-axis direction from the workpiece W. The traveling direction of the laser light L from the optical fiber 7 is the -x direction.

[0013] The oscillator 8 generates laser light L for processing. The laser light L generated by the oscillator 8 is transmitted through the optical fiber 7 and emitted from the fiber end 1 into the laser processing head 20. The type of oscillator 8 is not particularly limited as long as it is capable of generating laser light L. For example, the oscillator 8 may be a fiber laser oscillator, a direct diode laser, or a solid-state laser using a YAG crystal or the like as an excitation medium. The laser processing system 100 may also include a wavelength conversion unit that converts the wavelength of the laser light L generated by the oscillator 8. The wavelength conversion unit may be provided inside the oscillator 8 or outside the oscillator 8.

[0014] The control device 10 has a function of controlling the operation of the laser processing system 100 by controlling the operating conditions of the oscillator 8 and the laser processing head 20 .

[0015] The laser processing head 20 performs laser processing of the workpiece W by irradiating the workpiece W with laser light L supplied from the oscillator 8 via the optical fiber 7. The laser processing head 20 is equipped with a drive mechanism (not shown) and is capable of changing its position relative to the workpiece W. Note that although the laser processing head 20 is described as moving here, the position of the laser processing head 20 may be fixed and a table on which the workpiece W is placed may move, or both the laser processing head 20 and the table may move. A processing gas is supplied inside the laser processing head 20, and the processing gas is sprayed onto the workpiece W when the laser light L is irradiated onto the workpiece W.

[0016] The laser processing head 20 includes a collimating lens 2, a deflecting mirror 3, a condensing lens 4, an imaging optical system position change drive unit 41, imaging lenses 5-1 and 5-2, and photodetectors 6-1 and 6-2. The collimating lens 2 converts the laser light L incident on the laser processing head 20 from the fiber end 1 into a parallel beam. The deflecting mirror 3 is a partial reflection mirror that transmits a portion of the laser light L incident on the fiber end 1 and transmitted through the collimating lens 2 and reflects the other portion, thereby splitting the laser light L into light traveling along two optical paths. The condensing lens 4 focuses the laser light L reflected by the deflecting mirror 3 onto the workpiece W. The laser processing head 20 includes a processing nozzle that irradiates the laser light L focused by the condensing lens 4 onto the workpiece W. The processing nozzle has an opening on the optical path between the condensing lens 4 and the workpiece W, through which the laser light L and processing gas pass. The imaging optical system position change drive unit 41 is a drive unit that changes the positional relationship between the irradiation position of the condenser lens 4, which is an imaging optical system, and the workpiece W.

[0017] The imaging lens 5-1 forms an image on the photodetector 6-1 of a portion of the reflected light RL, which is the laser light L reflected by the work-piece W. The reflected light RL incident on the imaging lens 5-1 is a portion of the light reflected by the work-piece W and transmitted through the condenser lens 4, and is also the reflected light RL transmitted through the folding mirror 3. The imaging lens 5-1 is a reflected light imaging lens that forms an image of a portion of the reflected light RL.

[0018] The photodetector 6-1 is a reflected light sensor that detects reflected light RL from the workpiece W. The photodetector 6-1 detects the reflected light irradiation position, which is the incident position of the reflected light RL that enters the photodetector 6-1 via the bending mirror 3 and the imaging lens 5-1, and the amount of reflected light RL that enters the photodetector 6-1. The photodetector 6-1 outputs the detected reflected light irradiation position and amount of reflected light RL to the control device 10.

[0019] The imaging lens 5-2 forms an image on the photodetector 6-2 of a portion of the laser light L that is incident on the laser processing head 20 from the fiber end 1. The laser light L that is incident on the imaging lens 5-2 is a portion of the laser light L that has passed through the collimator lens 2 and is also a portion of the laser light L that has passed through the bending mirror 3. The imaging lens 5-2 is an incident light imaging lens that forms an image of a portion of the light incident on the laser processing head 20.

[0020] The photodetector 6-2 is an incident light sensor that detects the laser light L that is incident on the laser processing head 20. The photodetector 6-2 detects the incident light irradiation position, which is the incident position of the laser light L that is incident on the photodetector 6-2 via the bending mirror 3 and the imaging lens 5-2, and the light amount of the laser light L that is incident on the photodetector 6-2. The photodetector 6-2 outputs the detected incident light irradiation position and light amount of the laser light L to the control device 10.

[0021] The photodetectors 6-1 and 6-2 are preferably capable of measuring the irradiation position and light amount of the incident light and have a high measurement speed. For example, the photodetectors 6-1 and 6-2 are quadrant photodiodes or CMOS (Complementary Metal-Oxide-Semiconductor) cameras. Furthermore, since it is desired to measure the reflected light RL or the laser light L, it is desirable to use an optical filter such as a bandpass filter to extract only the oscillation wavelength of the laser light L. The optical filter such as a bandpass filter may be built into the photodetectors 6-1 and 6-2, or may be separately provided on the optical path upstream of the photodetectors 6-1 and 6-2.

[0022] Laser light L, which is emitted from an oscillator 8 via an optical fiber 7 and enters the laser processing head 20 from the fiber end 1, is irradiated onto the workpiece W via a collimating lens 2, a bending mirror 3, and a condensing lens 4. The bending mirror 3 splits a portion of the laser light L toward the imaging lens 5-2, which then forms an image on a photodetector 6-2. A portion of the laser light L irradiated onto the workpiece W becomes reflected light RL and enters the bending mirror 3 via the condensing lens 4. The reflected light RL incident on the bending mirror 3 splits into light that transmits toward the imaging lens 5-1 and light that is reflected and travels toward the fiber end 1. The reflected light RL incident on the imaging lens 5-1 forms an image on the photodetector 6-1. The reflected light RL reflected toward the fiber end 1 travels toward the fiber end 1 via the collimating lens 2. Depending on the angle at which the reflected light RL travels, the reflected light RL that has passed through the collimating lens 2 is incident on the fiber end 1. The reflected light RL may damage the optical components of the laser processing head 20, and if it is incident on the fiber end 1, it may cause a malfunction of the oscillator 8. Hereinafter, the reflected light RL that is incident on the fiber end 1 may be referred to as fiber reflected light.

[0023] FIG. 2 is an explanatory diagram of laser processing when the processing state is good. FIG. 3 is an explanatory diagram of laser processing when a penetration-impossible state occurs. The absorptivity of the wavelength of the laser light L for metal is lower in a solid state than in molten metal. Therefore, in a good processing state, as shown in FIG. 2, molten metal is generated and the laser light L travels in the optical axis direction of the laser light L, so the intensity of the reflected light RL to the laser processing head 20 is not high. However, if the processing state deteriorates, for example, when appropriate processing conditions are not set, the laser light L does not penetrate the workpiece W, but is reflected by the workpiece W, and the intensity of the reflected light RL increases, as shown in FIG. 3.

[0024] There is a correlation between the reflected light irradiation position and the amount of reflected light RL detected by the photodetector 6-1 and the amount of light reflected from the fiber. The reflected light RL is split by the bending mirror 3 into light directed toward the photodetector 6-1 and light directed toward the fiber end 1, with the split ratio being determined by the characteristics and arrangement of the bending mirror 3. Therefore, by detecting the amount of reflected light RL with the photodetector 6-1, the amount of reflected light RL directed toward the fiber end 1 can be determined. Furthermore, the angle at which the reflected light RL is incident on the condenser lens 4 and the bending mirror 3 changes depending on the surface condition of the workpiece W, etc. The incident position of the reflected light RL on the yz plane at the position of the fiber end 1 in the x-axis direction and the reflected light irradiation position both change depending on the angle at which the reflected light RL is incident on the bending mirror 3. There is a correlation between the incident position of reflected light RL on the yz plane at the position of fiber end 1 in the x-axis direction and the reflected light irradiation position, and by detecting the reflected light irradiation position with photodetector 6-1, it is possible to determine the range on the yz plane at the position of fiber end 1 where reflected light RL is irradiated. This makes it possible to determine the proportion of fiber-reflected light among the reflected light RL that travels from the bending mirror 3 toward the fiber end 1. Therefore, by photodetector 6-1 detecting the reflected light irradiation position and the light amount of reflected light RL, it is possible to determine the light amount of fiber-reflected light.

[0025] Furthermore, there is a correlation between the incident light irradiation position and the light intensity of the laser light L detected by the photodetector 6-2 and the light intensity of the fiber reflected light. The incident light irradiation position may change when the arrangement of the optical system in the laser processing head 20 is adjusted, or may change over time. Therefore, by using the detection data of the photodetector 6-2, the control device 10 can correct the effects of changes over time.

[0026] The optical system arrangement shown in FIG. 1 is merely an example, and various modifications are possible. For example, the collimating lens 2 and the imaging optical system may be single or multiple, as shown in FIG. 1 . The laser processing head 20 may also include a zoom optical system that changes the image diameter of the imaging point by displacing the position of the optical system. The laser processing head 20 may also include an optical system that displaces the irradiation position using the imaging optical system position change driver 41 by displacing the collimating lens 2 to adjust the divergence angle of the light incident on the imaging optical system. The optical components driven by the imaging optical system position change driver 41 may be one type or two or more types. The irradiation position may be located at the beam waist position of the optical system or may be shifted from the beam waist position. Changing the positional relationship between the imaging point of the laser light L and the workpiece W without changing the positional relationship between the laser processing head 20 and the workpiece W in the height direction, i.e., the z-axis direction in FIG. 1 , can be achieved by displacing the condenser lens 4, which is the imaging optical system, using the imaging optical system position change driver 41. The imaging optical system may be a condensing optical system, and the imaging lenses 5-1 and 5-2 may be fθ lenses.

[0027] The control device 10 controls the oscillator 8, the laser processing head 20, and a drive unit (not shown) based on processing parameters, which are numerical parameters related to laser processing, to perform laser processing. Specifically, the control device 10 controls a motor drive unit (not shown), which drives the motor in accordance with the control of the control device 10, thereby changing the relative position between the laser processing head 20 and the workpiece W. The control device 10 can also control laser processing by adjusting various processing conditions.

[0028] FIG. 4 is a diagram illustrating an example of a functional configuration of the control device 10 according to the first embodiment. The control device 10 includes a data acquisition unit 11, a reflected light estimation unit 12, and a control unit 13. The data acquisition unit 11 acquires data indicating the state of the laser processing system 100 from each unit of the laser processing system 100. Specifically, the data acquired by the data acquisition unit 11 includes the reflected light irradiation position and the light intensity of the reflected light RL output by the photodetectors 6-1 and 6-2, as well as the incident light irradiation position and the light intensity of the laser light L. Although not shown, the data acquisition unit 11 may also acquire information other than the data acquired by the photodetectors 6-1 and 6-2, such as detection data acquired by sensors other than the photodetectors 6-1 and 6-2 and processing conditions for laser processing. Depending on the type of acquired information, the data acquisition unit 11 can convert the acquired information into a time-series signal.

[0029] The reflected light estimation unit 12 estimates the amount of light reflected from the fiber based on the data acquired by the data acquisition unit 11. The reflected light estimation unit 12 may have a feature extraction function. In this case, the reflected light estimation unit 12 can extract feature values ​​from the data acquired by the data acquisition unit 11.

[0030] FIG. 5 is an explanatory diagram of the function of the reflected light estimation unit 12. An imaging lens 5-1 is disposed in front of the photodetector 6-1. If the focal length of the imaging lens 5-1 is f and the angle between the reflected light RL and the imaging lens 5-1 is θ, the irradiation position of the reflected light RL on the photodetector 6-1 is f tan θ. This allows the reflected light estimation unit 12 to determine the angular relationship between the laser light L and the reflected light RL. Furthermore, based on this angle information, the reflected light estimation unit 12 calculates the angle of the reflected light RL incident on the collimating lens 2, and can determine the amount of reflected light RL relative to the angle of the fiber reflected light from conditions such as the distance to the fiber end 1, information on the optical system arrangement of the collimating lens 2, and laser output. The amount of reflected light RL determined by the reflected light estimation unit 12 makes it possible to determine whether the reflected light RL reaching the fiber end 1 contributes to a malfunction of the oscillator 8 or the like. The reflected light estimation unit 12 outputs the determined amount of reflected light RL to the control unit 13. If the change over time in the optical axis of the laser light L is small and does not need to be detected, the photodetector 6-2 may be omitted.

[0031] Returning to the explanation of Fig. 4, the reflected light estimating unit 12 can estimate the amount of fiber reflected light based on at least the reflected light irradiation position and the amount of reflected light RL. In addition, the reflected light estimating unit 12 can use, for example, processing parameters, temperature information of the processing optical system inside the laser processing head 20, temperature changes of the processing optical system inside the laser processing head 20, the processing thickness, information on the processing material, etc.

[0032] The reflected light estimation unit 12 may output the estimation result to an output unit such as a display device inside or outside the laser processing system 100. The reflected light estimation unit 12 may output the estimation result regardless of the determined light intensity of the reflected light RL, or may output the estimation result only when it is determined that the determined light intensity of the reflected light RL may cause a malfunction of the oscillator 8 during processing. If it is determined that the malfunction of the oscillator 8 may occur, the reflected light estimation unit 12 may output a warning. The reflected light estimation unit 12 may display the estimation result on a display screen of a display device, or may output the estimation result as a sound output from an audio output device such as a speaker. Furthermore, if it is determined that the malfunction of the oscillator 8 may occur, the reflected light estimation unit 12 may issue a warning by turning on a patrol lamp.

[0033] The control unit 13 can control the operation of the entire laser processing system 100. At this time, the control unit 13 can control the laser processing system 100 based on the light amount calculated by the reflected light estimation unit 12, i.e., the light amount of the fiber-reflected light. Specifically, the control unit 13 has the function of an operating condition change unit that changes the operating conditions of the laser processing system 100 based on the light amount of the fiber-reflected light. At this time, the control unit 13 changes the operating conditions so that the light amount of the fiber-reflected light decreases. The operating conditions are processing conditions that are conditions related to processing, plus conditions that are not used during normal processing. For example, if the oscillator 8 has a component, such as a mechanical shutter, that can physically block the reflected light RL, taking measures such as blocking the reflected light RL is also included in the operating conditions. The processing conditions include, for example, the laser output, the beam quality of the laser light L, the processing gas pressure, the processing speed, the irradiation position of the imaging optical system, the imaging diameter of the imaging optical system, the pulse frequency of the laser light L, the pulse duty ratio of the laser light L, the magnification of the imaging optical system of the laser light L, the nozzle diameter of the nozzle provided in the laser processing head 20, the distance between the workpiece W and the nozzle, the type of mode of the laser light L, and the positional relationship between the center of the nozzle opening and the laser light L.

[0034] If the control unit 13 determines that there is a possibility of damaging the oscillator 8 based on the light intensity of the fiber-reflected light calculated by the reflected light estimation unit 12, it adjusts the operating conditions. Otherwise, it continues control under the current operating conditions. Whether or not there is a possibility of damaging the oscillator 8 is determined, for example, using a threshold value for the light intensity. The threshold value may be changed depending on processing conditions such as the plate thickness and the material of the workpiece W. The control unit 13 may also adjust the operating conditions using a model that changes the adjustment amount of the operating conditions based on the light intensity. Alternatively, the control unit 13 may determine the operating conditions using an evaluation formula that uses the reflected light irradiation position and light intensity detected by the photodetector 6-1 as explanatory variables. For example, the model used by the control unit 13 may output an evaluation value such as the degree of change over time. When adjusting the operating conditions, the control unit 13 can determine the adjustment content of the processing conditions, for example, the adjustment amount, based on the estimated light intensity output by the reflected light estimation unit 12 and the current operating conditions. When adjusting the operating conditions, the control unit 13 adjusts the operating conditions so as to reduce the light intensity of the fiber-reflected light. For example, adjustments to the operating conditions that reduce the amount of fiber reflected light include lowering the laser output, slowing the processing speed, turning off the power to the oscillator 8, physically blocking the emission of the laser light L with a mechanical shutter provided in the oscillator 8, and increasing the distance between the nozzle and the workpiece W. Slowing the processing speed causes the molten metal to flow downward and penetrate, thereby reducing the amount of reflected light RL. Increasing the distance between the nozzle and the workpiece W reduces the amount of reflected light RL reflected by the workpiece W that enters the laser processing head 20.

[0035] FIG. 6 is a flowchart illustrating an example of the operation of the control device 10 according to the first embodiment. FIG. 6 illustrates an operation for changing the operating conditions of the laser processing system 100. It is assumed that the oscillator 8 has already been activated and laser processing is being performed when the operation illustrated in FIG. 6 is started. The data acquisition unit 11 of the control device 10 acquires sensor data from the photodetectors 6-1 and 6-2 (step S101). The data acquisition unit 11 acquires the reflected light irradiation position, the amount of reflected light RL, the incident light irradiation position, and the amount of laser light L, which is the incident light, from the sensor data (step S102). The data acquisition unit 11 outputs the acquired data to the reflected light estimation unit 12. As described above, the data acquisition unit 11 may acquire sensor data from sensors other than the photodetectors 6-1 and 6-2, or may acquire data other than sensor data.

[0036] The reflected light estimation unit 12 estimates the amount of reflected light RL (fiber reflected light) incident on the fiber end 1 based on the data acquired by the data acquisition unit 11 (step S103). The control unit 13 determines whether the oscillator 8 is possibly damaged based on the amount of reflected light RL incident on the fiber end 1 estimated by the reflected light estimation unit 12 (step S104). If there is a possibility of damage (step S104: Yes), the control unit 13 adjusts the operating conditions to suppress the reflected light RL (step S105). Here, suppressing the reflected light RL includes not only suppressing the reflected light RL itself reflected by the workpiece W, but also suppressing the amount of reflected light RL incident on the fiber end 1 without changing the amount of reflected light RL itself reflected by the workpiece W. After adjusting the operating conditions, the control device 10 returns to step S101.

[0037] If it is determined that there is no possibility of damage (step S104: No), the control unit 13 continues processing under the current operating conditions (step S106), and returns to the operation of step S101.

[0038] Through the above process, the correction of the operating conditions is repeated until the estimated value of the amount of reflected light RL output by the reflected light estimating unit 12 is judged to be such that there is no possibility of damage to the oscillator 8.

[0039] As described above, according to the first embodiment, it is possible to provide a control device 10 that includes a data acquisition unit 11 that acquires a reflected light irradiation position, which is the incident position where a part of the reflected light RL, which is the laser light L incident from the fiber end 1 of the optical fiber 7 and reflected by the workpiece W, is incident on the photodetector 6-1, which is a reflected light sensor, and the amount of reflected light RL that is incident on the photodetector 6-1, which is a reflected light sensor, and a reflected light estimation unit 12 that estimates the amount of fiber reflected light, which is the other part of the reflected light RL that is reflected light RL that is incident on the fiber end 1, based on the reflected light irradiation position and the amount of reflected light RL that is incident on the photodetector 6-1, which is a reflected light sensor.

[0040] The reflected light irradiation position detected by the photodetector 6-1 correlates with the irradiation position of the reflected light RL at the fiber end 1. Therefore, by detecting the reflected light irradiation position, it is possible to determine the amount of light reflected by the workpiece W and incident on the fiber end 1. If the photodetector 6-1 only detects the amount of reflected light RL, it is possible to determine the amount of reflected light RL reaching the fiber end 1, but depending on the angle of the reflected light RL, some of the light may not be incident on the fiber end 1. Since the control device 10 can determine the amount of light incident on the fiber end 1, it is possible to interrupt processing only when truly necessary, thereby shortening processing downtime and improving productivity. The optical fiber 7 has a core layer and a cladding layer outside the core layer. By adjusting the refractive indexes of the cladding layer and the core layer, light is propagated to the central core layer. The emission angle of light emitted from the core layer can be determined by the maximum incident / emission angle NA at which light (propagation mode) that can propagate into the optical fiber 7 can be incident or emitted from the optical fiber 7. When there are multiple core layers, the fiber is called a multi-core fiber. The reflected light RL here may be measured by examining the amount of light irradiated onto the core layers, or the amount of light irradiated onto the cladding. Furthermore, the technology of the present disclosure can be applied whether the optical fiber 7 is a multi-core fiber or a single fiber.

[0041] Furthermore, the data acquisition unit 11 may acquire the incident light irradiation position, which is the incident position where a portion of the laser light L is incident on the photodetector 6-2, which is the incident light sensor, and the light amount of the laser light L incident on the photodetector 6-2, which is the incident light sensor, and the reflected light estimation unit 12 may estimate the light amount of the fiber reflected light based on the light amount of the reflected light RL incident on the photodetector 6-1, which is the reflected light sensor, the light amount of the laser light L incident on the photodetector 6-2, which is the incident light sensor, the reflected light irradiation position, and the incident light irradiation position. This makes it possible to detect not only the reflected light RL but also the position and light amount of the laser light L emitted from the fiber end 1 in real time, and to accurately determine whether or not the laser light L is incident on the fiber end 1.

[0042] The control device 10 may further include a control unit 13 that adjusts the operating conditions of the laser processing device that processes the workpiece W by irradiating the workpiece W with laser light L based on the light intensity of the fiber reflected light. In the first embodiment, the control unit 13 determines the operating conditions. However, the control device 10 may output an estimated value of the light intensity of the fiber reflected light and a laser processing state evaluated from the estimated value to assist the user in making a decision and prompt the user to change the operating conditions. For example, the laser processing system 100 may be controlled based on the operating conditions input by the user of the control device 10 who has viewed output information such as the estimated value of the light intensity of the fiber reflected light and the laser processing state evaluated from the estimated value.

[0043] The control unit 13 may also control the operating conditions based on the machining conditions, state quantities including the arrangement of the optical system of the laser machining apparatus and the state of the workpiece W, a model showing the relationship between the amount of fiber reflected light and the operating conditions, state quantities acquired externally, and the amount of fiber reflected light estimated by the reflected light estimation unit 12. Changing the operating conditions based on the machining conditions enables more accurate detection of machining abnormalities. The machining conditions include the laser output, the beam quality of the laser light L, the machining gas pressure, the machining speed, the irradiation position of the imaging optical system, the imaging diameter of the imaging optical system of the laser light L, the pulse frequency of the laser light L, the pulse duty ratio of the laser light L, the magnification of the imaging optical system, the nozzle diameter of the nozzle included in the laser machining head 20, the distance between the workpiece W and the nozzle, the type of mode of the laser light L, and the positional relationship between the center of the nozzle opening and the laser light L. The arrangement of the optical system includes, for example, the positional relationship of the imaging optical system and the position of the condenser lens 4. The state of the workpiece W includes, for example, the reflectance of the workpiece W, the surface state of the workpiece W such as rust, the material of the workpiece W, and the like.

[0044] The control unit 13 adjusts the operating conditions so as to reduce the amount of fiber-reflected light. For example, adjustments of the operating conditions that reduce the amount of fiber-reflected light include reducing the laser output, slowing the processing speed, turning off the power to the oscillator 8, physically blocking the emission of the laser light L using a mechanical shutter provided in the oscillator 8, and increasing the distance between the nozzle and the workpiece W. Slowing the processing speed causes the molten metal to flow downward and penetrate, thereby reducing the amount of reflected light RL. Increasing the distance between the nozzle and the workpiece W reduces the amount of reflected light RL reflected by the workpiece W that enters the laser processing head 20.

[0045] Furthermore, according to the first embodiment, a laser processing head 20 can be provided, which includes a focusing lens 4 that focuses the laser light L incident from the fiber end 1 of the optical fiber 7 onto the workpiece W, an imaging lens 5-1 that is a reflected light imaging lens that images a portion of the reflected light RL, which is the laser light L reflected by the workpiece W, and a photodetector 6-1 that is a reflected light sensor that detects the reflected light RL after passing through the imaging lens 5-1 that is the reflected light imaging lens, and the photodetector 6-1 that is the reflected light sensor detects the reflected light irradiation position, which is the position at which the reflected light RL enters the photodetector 6-1 that is the reflected light sensor, and the light amount of the reflected light RL.

[0046] The laser processing head 20 further includes an imaging lens 5-2, which is an incident light imaging lens that images a portion of the laser light L incident from the fiber end 1 of the optical fiber 7, and a photodetector 6-2, which is an incident light sensor that detects the laser light L after passing through the imaging lens 5-2, which is the incident light imaging lens. The photodetector 6-2, which is the incident light sensor, may detect the incident light irradiation position, which is the position at which the laser light L enters the photodetector 6-2, which is the incident light sensor, and the light amount of the laser light L incident on the photodetector 6-2, which is the incident light sensor.

[0047] Furthermore, according to the first embodiment, it is possible to provide a laser processing apparatus that uses laser light L incident from the fiber end 1 of the optical fiber 7 to laser process a workpiece W, the laser processing apparatus comprising: a focusing lens 4 that focuses the laser light L on the workpiece W; an imaging lens 5-1 that is a reflected light imaging lens that forms an image of a portion of the reflected light RL, which is the laser light L reflected by the workpiece W; a photodetector 6-1 that is a reflected light sensor that detects the reflected light irradiation position, which is the incident position of the reflected light RL after passing through the imaging lens 5-1 that is the reflected light imaging lens, and the amount of the reflected light RL; and a reflected light estimation unit 12 that estimates the amount of fiber reflected light, which is the reflected light RL that is another portion of the reflected light RL and is incident on the fiber end 1, based on the reflected light irradiation position and the amount of reflected light RL incident on the photodetector 6-1 that is the reflected light sensor.

[0048] Furthermore, according to the first embodiment, it is possible to provide a laser processing system 100 that performs laser processing on a workpiece W using laser light L incident from a fiber end 1 of an optical fiber 7, the laser processing system 100 including: a focusing lens 4 that focuses the laser light L on the workpiece W; an imaging lens 5-1 that is a reflected light imaging lens that forms an image of a portion of reflected light RL, which is the laser light L reflected by the workpiece W; a photodetector 6-1 that is a reflected light sensor that detects a reflected light irradiation position, which is the incident position of the reflected light RL after passing through the imaging lens 5-1 that is the reflected light imaging lens, and the amount of reflected light RL; and a reflected light estimation unit 12 that estimates the amount of fiber reflected light, which is the other portion of the reflected light RL that is reflected light RL that enters the fiber end 1, based on the reflected light irradiation position and the amount of reflected light RL that enters the photodetector 6-1 that is the reflected light sensor.

[0049] The laser processing system 100 may further include an imaging lens 5-2 which is an incident light imaging lens that images a portion of the laser light L incident from the fiber end 1 of the optical fiber 7, and a photodetector 6-2 which is an incident light sensor that detects the laser light L after passing through the imaging lens 5-2 which is the incident light imaging lens. The photodetector 6-2 which is the incident light sensor detects the incident light irradiation position which is the position at which the laser light L enters the photodetector 6-2 which is the incident light sensor, and the light amount of the laser light L incident on the photodetector 6-2 which is the incident light sensor, and the reflected light estimating unit 12 can estimate the light amount of the fiber reflected light based on the incident light irradiation position and the light amount of the laser light L incident on the photodetector 6-2 which is the incident light sensor.

[0050] The laser processing system 100 may further include a control unit 13 that adjusts the operating conditions of the laser processing system 100 based on the amount of light reflected from the fiber.

[0051] Furthermore, according to the first embodiment, it is possible to provide a laser processing method for laser processing a workpiece W using laser light L incident from the fiber end 1 of the optical fiber 7, the laser processing method including the steps of: forming an image of a portion of the reflected light RL, which is the laser light L reflected by the workpiece W, and making it incident on a photodetector 6-1, which is a reflected light sensor; detecting a reflected light irradiation position, which is the incident position of the reflected light RL on the photodetector 6-1, which is a reflected light sensor, and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor; and estimating the amount of fiber reflected light, which is the other portion of the reflected light RL and is reflected light RL incident on the fiber end 1, based on the reflected light irradiation position and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor.

[0052] 7 is a diagram showing an example of the functional configuration of a control device 10A according to embodiment 2. Although not shown, in embodiment 2, the system configuration is the same as in embodiment 1, and a system including a control device 10A instead of the control device 10 of embodiment 1 will be referred to as a laser processing system 100A.

[0053] The control device 10A includes a data acquisition unit 11, a reflected light estimation unit 12A, a control unit 13A, and a learned model storage unit 14. In the second embodiment, a learned model based on machine learning is used when the reflected light estimation unit 12A estimates the amount of light reflected from the fiber and when the control unit 13A determines the operating conditions based on the amount of light reflected from the fiber.

[0054] The trained model storage unit 14 stores trained models for inferring the light intensity of the fiber reflected light and operating conditions from state quantities including the processing conditions, the arrangement of the optical system of the laser processing apparatus, and the state of the workpiece W, the reflected light irradiation position, and the light intensity of the reflected light RL incident on the photodetector 6-1. Note that, although the trained model storage unit 14 is described here as being built into the control device 10A, the trained model storage unit 14 may also be provided in a device external to the control device 10A. Furthermore, the trained models stored in the trained model storage unit 14 may be trained for the laser processing apparatus controlled by the control device 10A, or may be trained for another laser processing apparatus.

[0055] For example, the trained model may be used to infer the amount of fiber reflected light and operating conditions from input data including the processing conditions during use, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1. Here, the output of the trained model is the amount of fiber reflected light and the operating conditions. However, the output of the trained model may be only the amount of fiber reflected light or only the operating conditions. Here, the operating conditions output by the trained model may be the set values ​​of the operating conditions or the amount of adjustment from the current values. Furthermore, the output of the trained model may further include the possibility of failure of the oscillator 8, the possibility of damage to the optical components of the laser processing head 20, etc.

[0056] In addition, the input data of the trained model may include the incident light irradiation position, which is the incident position of the laser light L incident on the photodetector 6-2, and the light amount of the laser light L incident on the photodetector 6-2.

[0057] The trained model may be trained using training data acquired from the laser processing system 100A to be controlled by the control device 10A, or may be trained using training data acquired from another laser processing system. When using a trained model trained using training data acquired from another laser processing system, it is desirable that the input data for the trained model include information regarding the configuration of the laser processing system 100A, such as the arrangement of the optical system of the laser processing apparatus.

[0058] The trained model may be obtained by performing machine learning using so-called supervised learning in accordance with a neural network model, for example. Here, supervised learning refers to a technique in which a learning device is provided with a set of input and result data, and the device learns the features of the training data and infers the result from the input.

[0059] A neural network is composed of an input layer consisting of multiple neurons, a hidden layer consisting of multiple neurons, and an output layer consisting of multiple neurons. The hidden layer may be one layer or two or more layers.

[0060] FIG. 8 is a diagram showing an example of a neural network used for machine learning in the second embodiment. FIG. 8 shows an example of a three-layer neural network. In the neural network shown in FIG. 8, when multiple inputs are input to input layers X1-X3, the values ​​are multiplied by weight V1 (v11-v16) and input to intermediate layers Y1-Y2, and the results are further multiplied by weight V2 (v21-v26) and output from output layers Z1-Z3. This output result varies depending on the values ​​of weights V1 and V2.

[0061] Here, the neural network learns the operating conditions through so-called supervised learning in accordance with learning data created based on a combination of the processing conditions, the reflected light irradiation position, the amount of reflected light RL incident on the photodetector 6-1, and the operating conditions.

[0062] That is, the neural network learns by inputting the processing conditions, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1 into the input layer, and adjusting the weights V1 and V2 so that the results output from the output layer approach the adjusted operating conditions.

[0063] Although the application of supervised learning to the learning algorithm has been described here, the present invention is not limited to this. In addition to supervised learning, reinforcement learning, unsupervised learning, semi-supervised learning, and the like can also be applied to the learning algorithm. Furthermore, deep learning, which learns to extract features themselves, can also be used as the learning algorithm, and machine learning may be performed according to other known methods, such as genetic programming, functional logic programming, and support vector machines.

[0064] The reflected light estimation unit 12A inputs input data to the trained model stored in the trained model storage unit 14, and acquires the light intensity and operating conditions of the fiber reflected light obtained as outputs. The reflected light estimation unit 12A regards the acquired light intensity of the fiber reflected light as an estimated value of the light intensity of the fiber reflected light. The reflected light estimation unit 12A also outputs the acquired operating conditions to the control unit 13A.

[0065] The control unit 13A controls the laser processing system 100A using operating conditions obtained by inputting input data into the trained model.

[0066] In the above description, the trained model outputs the amount of fiber reflected light and the operating conditions from input data including the machining conditions in use, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1. However, the configuration of the trained model is not limited to the above example as long as a similar function can be realized. For example, as a modified example, the control unit 13A may determine the operating conditions using a trained model that infers the operating conditions using the amount of fiber reflected light estimated by the reflected light estimation unit 12 of the first embodiment as input data. In this case, the amount of fiber reflected light used as input data may be calculated using a trained model, as in the case of the reflected light estimation unit 12A. In this case, the trained model storage unit 14 stores a first trained model for inferring the amount of fiber reflected light from the machining conditions in use, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1, and a second trained model for inferring the operating conditions from the amount of fiber reflected light.

[0067] As described above, according to the second embodiment, it is possible to provide a control device 10A that uses machine learning in addition to the functions of the first embodiment. The reflected light estimation unit 12A of the control device 10A can use the amount of fiber reflected light obtained by inputting the processing conditions currently in use and the reflected light irradiation position and the amount of reflected light RL acquired from the photodetector 6-1, which is a reflected light sensor, into a trained model for inferring the amount of fiber reflected light from input data including the processing conditions, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor, as an estimated value of the amount of fiber reflected light.

[0068] The control device 10A may also be provided with a control unit 13A that controls a laser processing device that processes a workpiece W by irradiating the workpiece W with laser light L using operating conditions obtained by inputting the processing conditions currently in use and the reflected light irradiation position and the amount of reflected light RL obtained from the photodetector 6-1, which is a reflected light sensor, into a learned model for inferring the operating conditions of the laser processing device that processes a workpiece W by irradiating the workpiece W with laser light L from input data including the processing conditions, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor.

[0069] Furthermore, the input data for the trained model used by the control device 10A may further include the incident light irradiation position, which is the incident position where a portion of the laser light L enters the photodetector 6-2, which is the incident light sensor, and the light amount of the laser light L that enters the photodetector 6-2, which is the incident light sensor. This makes it possible to perform inference based on the state acquired in real time, even if the irradiation position of the laser light L changes over time. Furthermore, when using a trained model trained using training data acquired by an apparatus other than the laser processing apparatus to be controlled by the control device 10A, accurate inference can be performed even if there are individual differences in the incident position of the laser light L for each laser processing apparatus.

[0070] The input data of the trained model may further include the arrangement of an optical system of a laser processing device that processes the workpiece W by irradiating the workpiece W with laser light L.

[0071] The control device 10A may also be provided with a control unit 13A that controls a laser processing device that processes a workpiece W by irradiating the workpiece W with laser light L, using operating conditions obtained by inputting the amount of fiber reflected light estimated by the reflected light estimation unit 12 into a learned model for inferring the operating conditions of the laser processing device from the amount of fiber reflected light.

[0072] Furthermore, according to the second embodiment, it is possible to provide a laser processing system 100A that includes a control unit 13A that controls the laser processing system 100A using operating conditions obtained by inputting the processing conditions currently in use and the reflected light irradiation position and the amount of reflected light RL acquired from the photodetector 6-1, which is a reflected light sensor, into a trained model for inferring operating conditions from input data including the processing conditions, the reflected light irradiation position, and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor.

[0073] Third Embodiment Fig. 9 is a diagram showing an example of the configuration of a laser processing system 100B according to a third embodiment. The laser processing system 100B has a laser processing head 20B instead of the laser processing head 20 of the laser processing system 100 according to the first embodiment. The other configurations are the same as those of the first embodiment, so detailed description thereof will be omitted here.

[0074] The laser processing head 20B includes a reflected-light removing optical element 9 on the optical path between the fiber end 1 and the workpiece W of the laser processing head 20 according to the first embodiment, more specifically, on the optical path between the fiber end 1 and the collimating lens 2. The reflected-light removing optical element 9 is a refractive optical element in which the magnitude of the change in angle between incident light and output light varies depending on whether the incident position on the reflected-light removing optical element 9 is at the center or the outer edge. The reflected-light removing optical element 9 has a first surface close to the fiber end 1 and a second surface opposite the first surface, and is positioned so that the laser light L emitted from the fiber end 1 and input to the first surface is input to the center. Furthermore, the reflected-light removing optical element 9 refracts light input to the outer edge of the second surface outward from the outer shape of the fiber end 1. This makes it possible to reduce the reflected light RL input to the fiber end 1. Although there remains a possibility that the reflected light RL incident on the center portion of the reflected-light removing optical element 9 may be incident on the fiber end 1, the control device 10 can reduce the reflected light from the fiber by adjusting the operating conditions, as described in embodiment 1. The function of the control device 10 is the same as that of embodiment 1, except that the presence of the reflected-light removing optical element 9 changes the correspondence between the reflected-light irradiation position detected by the photodetector 6-1 and the incident position of the reflected light RL on the yz plane at the position of the fiber end 1.

[0075] Furthermore, in FIG. 9, the laser processing system 100B includes the control device 10, but the control device 10A according to the second embodiment may be included instead of the control device 10.

[0076] As described above, according to the third embodiment, in addition to the configuration of the laser processing head 20 of the first embodiment, a laser processing head 20B can be provided which further includes a reflected light removal optical element 9, which is a refractive optical element in which the magnitude of the change in angle between the incident light and the outgoing light differs depending on whether the incident position is at the center or the outer edge, on the optical path between the fiber end 1 and the workpiece W, more specifically, on the optical path between the fiber end 1 and the collimating lens 2.

[0077] The reflected light elimination optical element 9 has a first surface close to the fiber end 1 and a second surface that is the backside of the first surface, and is positioned so that the laser light L emitted from the fiber end 1 and incident on the first surface is incident on the center portion, and has the property of refracting light incident on the outer edge of the second surface outward from the outer shape of the fiber end 1. This makes it possible to further reduce the reflected light RL incident on the fiber end 1. The reflected light elimination optical element 9 only needs to be able to change the angle between the incident light and the outgoing light, so it may be installed between the collimating lens 2 and the bending mirror 3, or between the bending mirror 3 and the condenser lens 4. Furthermore, although the above example shows the installation of one reflected light elimination optical element 9, multiple reflected light elimination optical elements 9 may also be installed.

[0078] Next, the hardware configuration of the control device 10, 10A will be described. The control device 10, 10A is realized, for example, by a computer system. The control device 10, 10A may be realized by one computer system or by multiple computer systems. For example, the control device 10, 10A may be realized using a cloud system. In a cloud system, the division between the computer system hardware and devices such as servers for each function can be arbitrarily set. For example, one computer system may have the functions of multiple devices, or multiple computer systems may have the functions of one device.

[0079] An example of the configuration of a computer system that realizes the control devices 10 and 10A will be described. Fig. 10 is a diagram showing an example of the configuration of a computer system that realizes the control devices 10 and 10A according to embodiments 1 to 3. As shown in Fig. 10, this computer system includes a control unit 101, an input unit 102, a storage unit 103, a display unit 104, a communication unit 105, and an output unit 106, which are connected via a system bus 107.

[0080] In FIG. 10 , the control unit 101 is, for example, a CPU (Central Processing Unit). The control unit 101 executes a control program that describes the processes performed by the control devices 10 and 10A of the first to third embodiments. The input unit 102 is composed of, for example, a keyboard, a mouse, and the like, and is used by a user of the computer system to input various information. The memory unit 103 includes various types of memory, such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and a storage device, such as a hard disk, and stores programs to be executed by the control unit 101, necessary data obtained during processing, and the like. The memory unit 103 is also used as a temporary storage area for programs. The display unit 104 is composed of, for example, an LCD (Liquid Crystal Display) and the like, and displays various screens to the user of the computer system. The communication unit 105 is, for example, a communication circuit that performs communication processing. The communication unit 105 may be composed of multiple communication circuits corresponding to multiple communication methods. The output unit 106 is an output interface that outputs data to external devices, such as a printer or external storage device.

[0081] Note that Fig. 10 is an example, and the configuration of the computer system is not limited to the example of Fig. 10. For example, the computer system may not include the output unit 106. Furthermore, when the functions of the control devices 10 and 10A are realized by multiple computer systems, not all of these computer systems may be the computer systems shown in Fig. 10. For example, some computer systems may not include at least one of the display unit 104, output unit 106, and input unit 102 shown in Fig. 10.

[0082] Here, an example of the operation of a computer system until a control program describing the processing of control device 10, 10A is ready to be executed will be described. In a computer system having the above configuration, for example, a control program is installed in storage unit 103 from a CD-ROM or DVD-ROM inserted in a CD (Compact Disc)-ROM drive or DVD (Digital Versatile Disc)-ROM drive (not shown). Then, when the control program is executed, the control program read from storage unit 103 is stored in an area that serves as the main storage device of storage unit 103. In this state, control unit 101 executes the processing of control device 10, 10A according to embodiments 1 to 3 in accordance with the control program stored in storage unit 103.

[0083] In the above description, a program describing the processing in the control device 10, 10A is provided using a CD-ROM or DVD-ROM as a recording medium, but this is not limited to this. Depending on the configuration of the computer system, the capacity of the program to be provided, etc., it is also possible to use a program provided via a transmission medium such as the Internet via the communication unit 105, for example.

[0084] The control program causes the computer to execute the steps of acquiring the reflected light irradiation position, which is the incident position where a portion of the reflected light RL, which is the laser light L incident from the fiber end 1 of the optical fiber 7 and reflected by the workpiece W, enters the photodetector 6-1, which is a reflected light sensor, and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor, and estimating the amount of fiber reflected light, which is the other portion of the reflected light RL that enters the fiber end 1, based on the reflected light irradiation position and the amount of reflected light RL incident on the photodetector 6-1, which is a reflected light sensor.

[0085] For example, the data acquisition unit 11 shown in Figures 4 and 7 is realized by the control unit 101, input unit 102, and memory unit 103 shown in Figure 10, the reflected light estimation unit 12, 12A shown in Figures 4 and 7 is realized by the control unit 101 and display unit 104, the control units 13, 13A shown in Figures 4 and 7 is realized by the control unit 101 shown in Figure 10, and the learned model memory unit 14 shown in Figure 7 is realized by the memory unit 103 shown in Figure 10.

[0086] 4 and 7 is an example, and as long as the laser processing systems 100, 100A, and 100B can perform the above-described operations, the division of functions in each device is not limited to the examples shown in Figures 4 and 7. For example, in the above, the control device 10, 10A and the laser processing head 20, 20B are combined to form the laser processing device, but the control device 10, 10A may be a device separate from the laser processing device, and the laser processing device may not have all of the functions of the control device 10, 10A.

[0087] The functions of the control devices 10 and 10A may also be implemented by dedicated hardware. For example, the functions of the control devices 10 and 10A may be implemented by a processing circuit 90 shown in FIG. 11. FIG. 11 is a diagram showing dedicated hardware for implementing the functions of the control devices 10 and 10A according to the first to third embodiments. The processing circuit 90 may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof.

[0088] Furthermore, some of the functions of the control devices 10 and 10A may be realized using the dedicated hardware shown in FIG. 11, and other parts may be realized using the computer system shown in FIG.

[0089] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0090] 1 Fiber end, 2 Collimating lens, 3 Bending mirror, 4 Condenser lens, 5-1, 5-2 Imaging lens, 6-1, 6-2 Photodetector, 7 Optical fiber, 8 Oscillator, 9 Reflected light removal optical element, 10, 10A Control device, 11 Data acquisition unit, 12, 12A Reflected light estimation unit, 13, 13A Control unit, 14 Learned model memory unit, 20, 20B Laser processing head, 41 Imaging optical system position change drive unit, 100, 100A, 100B Laser processing system, 101 Control unit, 102 Input unit, 103 Memory unit, 104 Display unit, 105 Communication unit, 106 Output unit, 107 System bus, L Laser light, RL Reflected light, W Processing object.

Claims

1. A control device comprising: a data acquisition unit that acquires a reflected light irradiation position, which is an incident position where a part of the reflected light reflected by the processing object of the laser light incident from the fiber end of the optical fiber enters the reflected light sensor, and the amount of the reflected light incident on the reflected light sensor; and a reflected light estimation unit that estimates the amount of the fiber reflected light, which is another part of the reflected light and is the reflected light incident on the fiber end, based on the reflected light irradiation position and the amount of the reflected light incident on the reflected light sensor.

2. The control device according to claim 1, wherein the data acquisition unit acquires an incident light irradiation position, which is an incident position where a part of the laser light enters the incident light sensor, and the amount of the laser light incident on the incident light sensor, and the reflected light estimation unit estimates the amount of the fiber reflected light based on the amount of the reflected light incident on the reflected light sensor, the amount of the laser light incident on the incident light sensor, the reflected light irradiation position, and the incident light irradiation position.

3. The control device according to claim 1 or 2, further comprising a control unit that adjusts an operating condition of a laser processing device that processes the processing object by irradiating the processing object with the laser light based on the amount of the fiber reflected light.

4. The control device according to claim 3, wherein the control unit controls the operating condition based on a model showing a relationship between a state quantity including a processing condition, an arrangement of an optical system included in the laser processing device, and a state of the processing object, the amount of the fiber reflected light, and the operating condition, the state quantity acquired from the outside, and the amount of the fiber reflected light estimated by the reflected light estimation unit.

5. The control device according to claim 3 or 4, wherein the control unit adjusts the operating condition so that the amount of the fiber reflected light decreases.

6. The control device according to any one of claims 1 to 5, wherein the reflected light estimation unit inputs the processing condition in use, the reflected light irradiation position and the amount of the reflected light acquired from the reflected light sensor into a learned model for inferring the amount of the fiber reflected light from input data including the processing condition, the reflected light irradiation position, and the amount of the reflected light incident on the reflected light sensor, and uses the obtained amount of the fiber reflected light as an estimated value of the amount of the fiber reflected light.

7. The control device according to claim 1 or 2, further comprising a control unit that controls a laser processing device that processes the workpiece by irradiating the laser light onto the workpiece using operating conditions obtained by inputting the processing conditions currently in use and the reflected light irradiation position and the amount of reflected light obtained from the reflected light sensor into a trained model for inferring the operating conditions of the laser processing device that processes the workpiece by irradiating the laser light onto the workpiece from input data including the processing conditions, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor.

8. The control device described in claim 6 or 7, characterized in that the input data of the trained model further includes an incident light irradiation position, which is the incident position where a portion of the laser light enters the incident light sensor, and the amount of light of the laser light that enters the incident light sensor.

9. A control device described in any one of claims 6 to 8, characterized in that the input data of the trained model further includes the arrangement of an optical system of a laser processing device that processes the object to be processed by irradiating the laser light onto the object to be processed.

10. A control device according to any one of claims 1 to 6, further comprising a control unit that controls a laser processing device that processes the object by irradiating the object with the laser light, using operating conditions obtained by inputting the amount of fiber reflected light estimated by the reflected light estimation unit into a trained model for inferring the operating conditions of the laser processing device from the amount of fiber reflected light.

11. A laser processing head comprising: a focusing lens that focuses laser light incident from the fiber end of an optical fiber onto a workpiece; a reflected light imaging lens that forms an image of a portion of the reflected light, which is the laser light reflected by the workpiece; and a reflected light sensor that detects the reflected light after passing through the reflected light imaging lens, wherein the reflected light sensor detects the reflected light irradiation position, which is the position at which the reflected light enters the reflected light sensor, and the amount of light of the reflected light.

12. A laser processing head as described in claim 11, further comprising an incident light imaging lens that images a portion of the laser light incident from the fiber end of the optical fiber, and an incident light sensor that detects the laser light after passing through the incident light imaging lens, wherein the incident light sensor detects the incident light irradiation position, which is the position at which the laser light enters the incident light sensor, and the light amount of the laser light that enters the incident light sensor.

13. A laser processing head as described in claim 11 or 12, further comprising a reflected light removal optical element, which is a refractive optical element in which the magnitude of the change in angle between incident light and outgoing light differs depending on whether the incident position is at the center or the outer edge, on the optical path between the fiber end and the workpiece.

14. The laser processing head described in claim 13, characterized in that the reflected light removal optical element has a first surface close to the fiber end and a second surface that is the back side of the first surface, and is positioned so that the laser light emitted from the fiber end and incident on the first surface is incident on the center part, and light that is incident on the outer edge part of the second surface is refracted outward beyond the outer shape of the fiber end.

15. A laser processing device that performs laser processing on an object to be processed using laser light incident from a fiber end of an optical fiber, comprising: a focusing lens that focuses the laser light on the object to be processed; a reflected light imaging lens that forms an image of a portion of the reflected light, which is the laser light reflected by the object to be processed; a reflected light sensor that detects a reflected light irradiation position, which is the incident position of the reflected light after passing through the reflected light imaging lens, and the amount of the reflected light; and a reflected light estimation unit that estimates the amount of fiber reflected light, which is the reflected light that is another portion of the reflected light and enters the fiber end, based on the reflected light irradiation position and the amount of the reflected light that enters the reflected light sensor.

16. A laser processing system for laser processing an object to be processed using laser light incident from a fiber end of an optical fiber, comprising: a focusing lens that focuses the laser light on the object to be processed; a reflected light imaging lens that forms an image of a portion of the reflected light, which is the laser light reflected by the object to be processed; a reflected light sensor that detects a reflected light irradiation position, which is the incident position of the reflected light after passing through the reflected light imaging lens, and the amount of the reflected light; and a reflected light estimation unit that estimates the amount of fiber reflected light, which is the other portion of the reflected light that is reflected light that enters the fiber end, based on the reflected light irradiation position and the amount of the reflected light that enters the reflected light sensor.

17. The laser processing system according to claim 16, further comprising: an incident light imaging lens that images a portion of the laser light incident from the fiber end of the optical fiber; and an incident light sensor that detects the laser light after passing through the incident light imaging lens, wherein the incident light sensor detects an incident light irradiation position, which is the position at which the laser light enters the incident light sensor, and the amount of laser light that enters the incident light sensor, and the reflected light estimation unit estimates the amount of light reflected from the fiber based on the incident light irradiation position and the amount of laser light that enters the incident light sensor.

18. The laser processing system according to claim 16 or 17, further comprising a control unit that adjusts the operating conditions of the laser processing system based on the amount of light reflected from the fiber.

19. The laser processing system described in claim 18, characterized in that the control unit controls the laser processing system using operating conditions obtained by inputting the processing conditions currently in use, the reflected light irradiation position and the amount of reflected light obtained from the reflected light sensor into a trained model for inferring the operating conditions from input data including the processing conditions, the reflected light irradiation position, and the amount of reflected light incident on the reflected light sensor.

20. A laser processing method for laser processing an object to be processed using laser light incident from a fiber end of an optical fiber, comprising the steps of: forming an image of a portion of the reflected light, which is the laser light reflected from the object to be processed, and making it incident on a reflected light sensor; detecting a reflected light irradiation position, which is the position at which the reflected light enters the reflected light sensor, and the amount of the reflected light incident on the reflected light sensor; and estimating the amount of fiber reflected light, which is the other portion of the reflected light and is the reflected light that enters the fiber end, based on the reflected light irradiation position and the amount of the reflected light incident on the reflected light sensor.

Images