Laser cutting quality detection method and detection device

Abstract

The invention belongs to the technical field of laser cutting, and discloses a laser cutting quality detection method and device. The laser cutting quality detection method comprises the following steps: separating light into a laser band light beam and a visible light band light beam through a light splitting piece; detecting the energy of the laser wave band light beam through a laser energy meter to judge whether the workpiece is penetrated by the laser or not; detecting the position deviation of the laser spot relative to the center of the nozzle and / or the shape and size of the kerf on the workpiece through imaging equipment according to the image; and a detection result obtained according to the laser band light beam and the visible light band light beam is compared with a preset threshold value, the cutting quality is evaluated in real time according to a comparison result, and an evaluation result is recorded or displayed. The reflection quantity of the laser is detected by utilizing the characteristic that the workpiece can reflect the laser, and whether the workpiece is penetrated or not can be accurately judged. And laser parameters can be accurately adjusted according to specific parameters, so that the cutting quality of workpieces is improved.

Description

Technical Field

[0001] The present invention relates to the field of laser cutting technology, and in particular to a laser cutting quality detection method and a detection device. Background Art

[0002] During the laser cutting process, the laser is focused from top to bottom through the optical path system onto the surface of the workpiece (such as a steel plate) for processing. During actual cutting, it is necessary to ensure that the laser beam is coaxial with the nozzle and maintain a suitable focal position to ensure the consistency and stability of the cutting gap. At the same time, when the laser performs initial perforation and subsequent cutting on an unperforated steel plate, in order to achieve real-time monitoring of process quality and parameters, it is necessary to detect quality parameters such as the perforation of the steel plate, the spot size of the laser beam, the concentricity of the spot with the nozzle, and the slit width, so as to adjust the processing parameters and improve the cutting quality of the workpiece.

[0003] The existing laser cutting quality detection method can only give two states of qualified or unqualified for the above-mentioned quality parameters, and cannot reflect the changing curve of cutting state and cutting quality in real time during the cutting process; therefore, it is impossible to adjust the processing parameters in real time according to the detected parameters during the cutting process, which limits the improvement of workpiece cutting quality. Summary of the invention

[0004] The purpose of the present invention is to provide a laser cutting quality detection method and detection device, so that the quality parameters can be detected in real time during the cutting process, and the processing parameters can be adjusted in real time according to the detected parameters, ultimately achieving the effect of improving the cutting quality of the workpiece.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] Laser cutting quality inspection methods include:

[0007] A laser cutting quality detection method is applied to a laser cutting device having a laser emitter, an optical path system and a nozzle, and the laser cutting quality detection method comprises:

[0008] When laser cutting is performed on a workpiece, a beam splitter provided in the laser cutting device is used to separate the light reflected from the workpiece and the nozzle area into a laser band beam and a visible light band beam;

[0009] The energy of the laser band light beam is detected by a laser energy meter, and it is determined whether the workpiece has been penetrated by the laser. If it is detected that the workpiece has been penetrated, an instruction is output to the control system of the laser cutting equipment to make the cutting head enter the subsequent cutting stage or move to the next processing position; if it is detected that the workpiece has not been penetrated, the processing is continued or the cutting parameters are adjusted;

[0010] Acquire the image of the workpiece surface and the bottom of the nozzle formed by the visible light beam through an imaging device, and detect the position deviation of the laser spot relative to the center of the nozzle and / or the shape and size of the slit on the workpiece according to the image;

[0011] If it is determined that the position deviation and / or the slit size exceeds a preset range, an adjustment instruction is output to a control system of the laser cutting device to perform automatic correction of the focus position or the concentricity of the light beam;

[0012] The detection results obtained according to the laser band light beam and the visible light band light beam are compared with a preset threshold value, the cutting quality is evaluated in real time according to the comparison result, and the evaluation result is recorded or displayed.

[0013] Preferably, the light splitting element comprises a first light splitting prism and a first filter, wherein:

[0014] The first beam splitter prism is used to split the light beam reflected back from the workpiece into a first channel and a second channel. The first filter is arranged in the first channel. The first filter filters out the visible light band to obtain the laser band light beam.

[0015] Preferably, the light splitting ratio between the first channel and the second channel is 3:7.

[0016] Preferably, the light splitter further comprises: a second light splitter and a second filter, wherein:

[0017] The second beam splitter is used to split the light beam of the second channel into a third channel and a fourth channel. The second filter is arranged in the third channel. The second filter filters out the laser band light beam to obtain the visible light band.

[0018] Preferably, the splitting ratio of the third channel to the fourth channel is 3:4.

[0019] Preferably, the energy of the visible light band in the third channel is detected by a visible light energy meter;

[0020] If the measured value of the laser energy meter is less than the threshold value and the measured value of the visible light energy meter is greater than the threshold value, it is determined that the workpiece has been penetrated by the laser; if the measured value of the laser energy meter is greater than the threshold value and the measured value of the visible light energy meter is less than the threshold value, it is determined that the workpiece has not been penetrated by the laser.

[0021] Preferably, when the laser transmitter is working, it triggers the laser energy meter and the visible light energy meter to start simultaneously.

[0022] Preferably, the position of the nozzle is determined by identifying the contour of a circle in the image, and the center of the nozzle is determined;

[0023] The position and outline of the laser spot are determined by identifying the bright part in the image, and the size of the laser spot and the position deviation of the laser spot relative to the center of the nozzle are determined by taking the center position of the nozzle as the reference point and the radius of the nozzle as the reference size.

[0024] Preferably, the actual contour of the nozzle is compared with a reference circle formed with the center position of the nozzle as a reference point to determine the deformation amount and deformation range of the nozzle.

[0025] A detection device is used to implement a laser cutting quality detection method, and the detection device includes:

[0026] The controller determines whether the workpiece has been penetrated by the laser, detects the position deviation of the laser spot relative to the nozzle center and / or the shape and size of the cutting seam in the image, and controls the operation of each execution component in the laser cutting device.

[0027] Beneficial effects of the present invention:

[0028] The laser cutting quality detection method of the present invention separates the laser band light beam and the visible light band light beam from the light reflected back from the workpiece and the nozzle area. Since the metal workpiece can reflect light, the amount of laser reflected upward after the laser penetrates the workpiece during the process of cutting the workpiece is small, and vice versa. When the laser frequency remains unchanged and other conditions are fixed, the greater the amount of laser reflection, the greater the laser energy, so that whether the workpiece is penetrated is determined by the energy of the laser band light beam. At the beginning of cutting, the power and / or frequency of the laser can be accurately adjusted according to this method to accurately adapt to workpieces of different thicknesses and different materials, reduce quality problems caused by inappropriate laser power and frequency, and also take into account certain energy saving, that is, the power of the laser will not be too high to cause waste of electric energy. In addition, the light collection point is located directly above the workpiece, so that the final image is an image of the surface of the workpiece facing forward, the image does not need to be corrected, and is relatively clear, and the position deviation of the laser spot relative to the nozzle center and / or the shape and size of the slit on the workpiece can be calculated through the image, so that the processing parameters can be accurately adjusted according to specific parameters to improve the cutting quality of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the detection device of the present invention;

[0030] Figure 2 It is a flow chart of the laser cutting quality detection method of the present invention.

[0031] In the figure:

[0032] 100. First light beam; 1. Beam combiner; 11. Reflector; 21. First beam splitter prism; 22. Second beam splitter prism; 23. Third filter; 3. Imaging device; 4. Laser energy meter; 5. Visible light energy meter. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0034] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0037] Refer to the following Figure 1 to Figure 2 The laser cutting quality detection method and detection device provided by the present invention are described.

[0038] The detection device is installed on the laser cutting equipment, and the laser cutting equipment has a laser emitter, an optical path system, a laser head and a nozzle, which are arranged in order from top to bottom. The laser emitter can generate laser, and the optical path system can focus the laser into a high-power density laser beam, which is irradiated from the nozzle to the surface of the workpiece to cut the workpiece. The focusing lens inside the optical path system can be adjusted in the vertical and horizontal directions to adjust the size and position of the laser spot.

[0039] Reference Figure 1 The detection device specifically includes a beam combiner 1, a beam splitter, an imaging device 3 and a controller, wherein the beam combiner 1 is connected inside the optical path system, and has a light-transmitting surface and a reflective surface that are relatively arranged, the top surface of the beam combiner 1 is the light-transmitting surface, and the bottom surface of the beam combiner 1 is the reflective surface, that is, the reflective surface faces the surface of the workpiece; so that the laser beam can penetrate the beam combiner 1 downward to irradiate the surface of the workpiece, and the beam combiner 1 reflects the light at its bottom to the light-emitting side of the beam combiner 1, and forms a first light beam 100 on the light-emitting side of the beam combiner 1.

[0040] A reflector 11 is arranged on one side of the beam combiner 1. The reflector 11 is arranged parallel to the beam combiner 1. The reflector 11 is connected to the outside of the optical path system. The first light beam 100 changes its transmission direction from a horizontal direction to a vertical upward direction through the reflector 11, thereby reducing the space required by the detection device in the horizontal direction.

[0041] The beam splitter comprises a first beam splitter prism 21, a first filter, a second beam splitter prism 22, a second filter and a third filter 23. The first beam splitter prism 21 and the second beam splitter prism 22 are sequentially arranged above the reflector 11 from bottom to top. Specifically, in the present embodiment, the first beam splitter prism 21 and the second beam splitter prism 22 are preferably polarization beam splitter prisms. The polarization beam splitter prism is formed by gluing a pair of high-precision right-angle prisms. The polarization beam splitter prism can split the incident non-polarized light into two vertical linear polarized light beams, that is, each prism has an incident surface and two exit surfaces, and the incident surface of each prism faces downward, wherein the first exit surface faces upward, and the second exit surface faces the side. In addition, the polarization beam splitter prism has the characteristics of low stress, high extinction ratio, good imaging quality, small beam deflection angle, etc., and its wavelength covers a wide range, and can be applied from 420nm to 1600nm.

[0042] The first beam splitter 21 splits the first light beam 100 into a first channel and a second channel, wherein the first channel is upward and the second channel is toward the side, the first filter is arranged on the second exit surface of the first beam splitter 21, and the first filter filters out the visible light band to obtain the laser band light beam, and a laser energy meter 4 is also arranged on one side of the first filter. The second beam splitter 22 splits the refracted first light beam 100 into a third channel and a fourth channel, wherein the third channel is upward and the fourth channel is toward the side, the second filter is arranged on the second exit surface of the second beam splitter 22, and the second filter filters out the laser band light beam band to obtain visible light, and a visible light energy meter 5 is also arranged on one side of the second filter.

[0043] Specifically, the first filter can filter light with a wavelength less than or equal to 1000nm, the second filter can filter light with a wavelength less than or equal to 400nm and light with a filter length greater than or equal to 850nm, and only allows light with a wavelength of 400nm-850nm to pass through, thereby filtering the laser to obtain a third light beam of only visible light.

[0044] Further, the light splitting ratio of the first channel to the second channel is 3:7, and the light splitting ratio of the third channel to the fourth channel is 3:4, that is, the light splitting ratio of the first channel, the third channel and the fourth channel is 3:3:4.

[0045] The imaging device 3 in this embodiment is a CCD camera. The third filter 23 and the CCD camera are arranged above the second dichroic prism 22 from bottom to top. The third filter 23 and the second filter can filter the same light, so that the first light beam 100 can be refracted on both sides to form an image on the CCD camera. The CCD camera is electrically connected to the controller, and the image is collected through the controller, and the image is calculated and analyzed.

[0046] Furthermore, the laser energy meter 4, the visible light energy meter 5, and the CCD camera are all electrically connected to the controller, and the controller is electrically connected to the control system of the laser cutting equipment. After acquiring the data of the laser energy meter 4 and the visible light energy meter 5, the controller can store and calculate the data to determine whether the workpiece has been penetrated by the laser, and send instructions to the control system to control the operation of the execution components in the laser cutting equipment. After acquiring the image taken by the CCD camera, the controller detects the position deviation of the laser spot relative to the nozzle center and the shape and size of the slit in the image, and controls the operation of each execution component in the laser cutting equipment to perform automatic correction of the focus position and the concentricity of the beam.

[0047] Reference Figure 1 and Figure 2 The laser cutting quality detection method is based on the above detection device for detection, and the laser cutting quality detection method includes:

[0048] S1. When laser cutting is performed on a workpiece, the light reflected from the workpiece and the nozzle area is separated into a laser band light beam and a visible light band light beam through a beam splitter.

[0049] In step S1, the light is reflected by the beam combiner 1, and the first light beam 100 is reflected by the reflector 11, so that the first light beam 100 is changed from a horizontal direction to a vertical upward direction. The laser band light beam is separated from the first light beam 100 by the first beam splitter prism 21 and the first filter, and the visible light band light beam is separated from the first light beam 100 by the second beam splitter prism 22 and the second filter.

[0050] S2. Detect the intensity or energy of the laser band light beam through the laser energy meter 4, and determine whether the workpiece has been penetrated by the laser. If it is detected that the workpiece has been penetrated, output instructions to the controller of the laser cutting system to make the cutting head enter the subsequent cutting stage or move to the next processing position; if it is detected that the workpiece has not been penetrated, continue processing or adjust cutting parameters.

[0051] Specifically, a first boundary value and a second boundary value are preset in the system database, the value detected by the laser energy meter 4 is the first measurement value, and the value detected by the visible light energy meter 5 is the second measurement value. If the first measurement value is greater than the first boundary value and the second measurement value is less than the second boundary value, it means that the laser cannot penetrate the workpiece and the visible light under the workpiece cannot penetrate the workpiece, then it is determined that the workpiece is not penetrated; if the first measurement value is less than the first boundary value and the second measurement value is greater than the second boundary value, then it is determined that the workpiece is penetrated.

[0052] It can be seen that the metal workpiece cut by the laser cutting equipment has a certain mirror effect and can reflect light to a certain extent. Therefore, when the laser is irradiated on the surface of the workpiece, the laser will be reflected upward, that is, when the laser does not penetrate the workpiece, there is a large amount of laser in the first beam 100, but after penetrating the workpiece, less laser is reflected upward, and the visible light passing through the workpiece slit also increases. In addition, when the laser power, frequency and other conditions (such as the shape and size of the light spot) are fixed, the greater the amount of laser reflection, the greater the energy of the laser.

[0053] Based on the above-mentioned specific situation, the data of the laser energy meter 4 can basically determine whether the workpiece is penetrated, that is, the first measured value is greater than the first boundary value, indicating that the laser cannot penetrate the workpiece. However, in this embodiment, other uncertain factors such as sensor failure are also considered, and the data of the visible light energy meter 5 is added for auxiliary verification, so that the state of the workpiece can be determined more accurately. In the actual cutting operation process, the matching processing parameters are first selected in the database of the controller according to the thickness and material of the workpiece, and then the state of the workpiece is detected during the cutting process, so as to accurately adjust the processing parameters. For example, if the workpiece cannot be penetrated under the current laser power, the power can be gradually increased for testing, so that accurate processing parameters can be obtained for the workpiece, and finally accurately adapted to workpieces of different thicknesses and different materials, reducing quality problems caused by inappropriate laser power and frequency. At the same time, this method can reduce the power of the laser as much as possible under the premise of cutting through the workpiece, so as to take into account certain energy saving and reduce the waste of electric energy.

[0054] In addition, compared to arranging an additional detection device outside the optical path system to detect the state of the workpiece, in this detection method, the detection device needs to be arranged outside the optical path system away from the forward direction of cutting. During the cutting operation, the optical path system needs to move forward a certain distance before the state of the workpiece can be detected, which has a certain hysteresis. The detection position of the present invention is located directly above the nozzle, so the device can obtain the workpiece more timely and adjust the processing parameters, thereby reducing the invalid cutting stroke and helping to improve the cutting power. It should be noted that the processing parameters in this embodiment include but are not limited to: laser power, laser frequency, and cutting speed.

[0055] Optionally, in some other embodiments, it may be determined whether the workpiece is penetrated by only comparing the first measurement value and the first boundary value.

[0056] Furthermore, in step S2, when the laser generator is working, the trigger laser energy meter 4 and the visible light energy meter 5 are started at the same time. It can be understood that the trigger laser energy meter 4 and the visible light energy meter 5 enter the working state only when there is laser passing through the inside of the optical path system, and when the laser generator stops working, the trigger laser energy meter 4 and the visible light energy meter 5 also stop working. Therefore, it can not only prevent misjudgment when the laser generator stops working, but also improve the accuracy of detection; in addition, it can also shorten the working time of the trigger laser energy meter 4 and the visible light energy meter 5, thereby extending the service life of the trigger laser energy meter 4 and the visible light energy meter 5.

[0057] S3. The image of the workpiece surface and the bottom of the nozzle formed by the visible light beam is obtained by the imaging device 3. The position deviation of the laser spot relative to the center of the nozzle and / or the shape and size of the slit on the workpiece are detected based on the image. If it is determined that the position deviation and / or the slit size exceeds the preset range, an adjustment instruction is output to the controller of the laser cutting system to perform automatic correction of the focus position or the concentricity of the beam. In this embodiment, the position deviation of the laser spot and the shape and size of the slit on the workpiece can be calculated.

[0058] The detection results obtained based on the laser band light beam and the visible light band light beam are compared with the preset threshold value, the cutting quality is evaluated in real time based on the comparison result, and the evaluation result is recorded or displayed.

[0059] Specifically, the imaging device 3 is a CCD camera. As mentioned above, the CCD camera is selected as the imaging device 3 because the CCD camera has the advantages of high image quality, wide dynamic range, global shutter function, good consistency, small size and light weight, low energy consumption, strong resistance to strong light and vibration, and long life. In particular, the CCD camera has a large dynamic range and can handle bright and dim areas well in the same image at the same time, reducing overexposure or underexposure, making the performance better when shooting high-contrast scenes. This feature can be used to facilitate the distinction between the laser part and the visible light part in the image, thereby improving the detection accuracy.

[0060] After the CCD camera captures the image, the position of the nozzle is determined by identifying the circular outline in the image, and the center of the nozzle is determined. It should be noted that the images here are multiple images taken continuously by the CCD camera, including the image of the laser beam just irradiated on the surface of the workpiece and the image after the laser beam penetrates the workpiece. After determining the center of the nozzle, the actual outline of the nozzle is compared with the reference circle formed with the center position of the nozzle as the reference point, so that the deformation amount and deformation range of the nozzle can be determined. The deformation amount here is the maximum distance between the actual outline of the nozzle and the reference circle, and the deformation range is the total length of the position where the nozzle is deformed.

[0061] Furthermore, if the deformation of the nozzle is too large or the deformation range is too large, the nozzle needs to be replaced. For example, in this embodiment, when the deformation of the nozzle reaches one-quarter of the nozzle radius, the nozzle needs to be replaced. In this embodiment, when the deformation range of the nozzle reaches one-quarter of the nozzle circumference, the nozzle needs to be replaced. It should be noted that in some other embodiments, the replacement standard can be adaptively adjusted according to the actual operation conditions.

[0062] In addition, after determining the center of the nozzle, the position and outline of the laser spot are determined by identifying the bright part in the image. The center of the nozzle is used as the reference point, and the radius of the nozzle is used as the reference size to determine the size and position deviation of the laser spot. Since the radius of the nozzle is known and fixed, the size and position deviation of the spot can be accurately measured by comparing the ratio between the spot and the nozzle in the image. After obtaining the deviation, the controller can adjust the optical path system to adjust the size and position deviation of the spot to within the set range. The specific adjustment method is: if there is a position deviation of the spot, the horizontal position of the focusing lens inside the optical path system is adjusted in the horizontal direction. If there is a size deviation of the spot, the height of the focusing lens is adjusted in the vertical direction to achieve the adjustment of the spot size.

[0063] In addition, during the laser cutting process of the workpiece, the nozzle moves in a predetermined direction, and the slit is located in a position in the image away from the nozzle's forward direction. At this time, the radius of the nozzle is also used as the reference size to accurately calculate the width of the slit, so that the processing parameters are corrected according to the width of the slit to ensure the cutting quality of the workpiece.

[0064] Step S2 in the laser cutting quality detection method also includes: the first beam splitter prism 21 and the second beam splitter prism 22 both refract 30% of the light in the first light beam 100. It can be understood that the laser energy meter 4, the visible light energy meter 5 and the CCD camera respectively obtain 30%, 30% and 40% of the light in the first light beam 100. First, the light supply of the laser energy meter 4 and the visible light energy meter 5 is ensured so that the laser energy meter 4 and the visible light energy meter 5 can work normally to avoid excessive detection errors due to insufficient light supply; the light allocated to the CCD camera is more than that of the laser energy meter 4 and the visible light energy meter 5, so that the CCD camera can obtain more light to improve the clarity and brightness of the image, and finally improve the quality of the image to ensure the detection accuracy of the quality parameters. It should be noted that the above-mentioned splitting ratio is the optimal splitting ratio obtained after a large number of experiments.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A laser cutting quality detection method, characterized in that: Applied to a laser cutting device having a laser emitter, an optical path system and a nozzle, the laser cutting quality detection method comprises: When laser cutting is performed on a workpiece, a beam splitter provided in the laser cutting device is used to separate the light reflected from the workpiece and the nozzle area into a laser band beam and a visible light band beam; The energy of the laser band light beam is detected by a laser energy meter, and it is determined whether the workpiece has been penetrated by the laser. If it is detected that the workpiece has been penetrated, an instruction is output to the control system of the laser cutting equipment to make the cutting head enter the subsequent cutting stage or move to the next processing position; if it is detected that the workpiece has not been penetrated, the processing is continued or the cutting parameters are adjusted; Acquire the image of the workpiece surface and the bottom of the nozzle formed by the visible light beam through an imaging device, and detect the position deviation of the laser spot relative to the center of the nozzle and / or the shape and size of the slit on the workpiece according to the image; If it is determined that the position deviation and / or the slit size exceeds a preset range, an adjustment instruction is output to a control system of the laser cutting device to perform automatic correction of the focus position or the concentricity of the light beam; The detection results obtained according to the laser band light beam and the visible light band light beam are compared with a preset threshold value, the cutting quality is evaluated in real time according to the comparison result, and the evaluation result is recorded or displayed.

2. The laser cutting quality detection method according to claim 1, characterized in that: The light splitting element comprises a first light splitting prism and a first filter, wherein: The first beam splitter prism is used to split the light beam reflected back from the workpiece into a first channel and a second channel. The first filter is arranged in the first channel. The first filter filters out the visible light band to obtain the laser band light beam.

3. The laser cutting quality detection method according to claim 2, characterized in that: The light splitting ratio between the first channel and the second channel is 3:

7.

4. The laser cutting quality detection method according to any one of claims 2 or 3, characterized in that: The light splitter also includes: a second light splitter and a second filter, wherein: The second beam splitter is used to split the light beam of the second channel into a third channel and a fourth channel. The second filter is arranged in the third channel. The second filter filters out the laser band light beam to obtain the visible light band.

5. The laser cutting quality detection method according to claim 4, characterized in that: The light splitting ratio of the third channel and the fourth channel is 3:

4.

6. The laser cutting quality detection method according to claim 4, characterized in that: Detecting the energy of the visible light band in the third channel by a visible light energy meter; If the measured value of the laser energy meter is less than the threshold value, and the measured value of the visible light energy meter is greater than the threshold value, it is determined that the workpiece has been penetrated by the laser; If the measured value of the laser energy meter is greater than the threshold value, and the measured value of the visible light energy meter is less than the threshold value, it is determined that the workpiece is not penetrated by the laser.

7. The laser cutting quality detection method according to claim 6, characterized in that: When the laser transmitter is working, it triggers the laser energy meter and the visible light energy meter to start simultaneously.

8. The laser cutting quality detection method according to claim 1, characterized in that: Determine the position of the nozzle by identifying the outline of the circle in the image, and determine the center of the nozzle; The position and outline of the laser spot are determined by identifying the bright part in the image, and the size of the laser spot and the position deviation of the laser spot relative to the center of the nozzle are determined by taking the center position of the nozzle as the reference point and the radius of the nozzle as the reference size.

9. The laser cutting quality detection method according to claim 8, characterized in that: The actual contour of the nozzle is compared with a reference circle formed with the center position of the nozzle as a reference point to determine the deformation amount and deformation range of the nozzle.

10. A detection device, characterized in that Used to implement the laser cutting quality detection method according to any one of claims 1 to 9, the detection device comprises: The controller determines whether the workpiece has been penetrated by the laser, detects the position deviation of the laser spot relative to the nozzle center and / or the shape and size of the cutting seam in the image, and controls the operation of each execution component in the laser cutting device.

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