CN115138992A - System and method for determining zero focus of laser cutting head - Google Patents
System and method for determining zero focus of laser cutting head Download PDFInfo
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- CN115138992A CN115138992A CN202210963682.0A CN202210963682A CN115138992A CN 115138992 A CN115138992 A CN 115138992A CN 202210963682 A CN202210963682 A CN 202210963682A CN 115138992 A CN115138992 A CN 115138992A
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- 238000003698 laser cutting Methods 0.000 title claims abstract description 31
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- 206010063385 Intellectualisation Diseases 0.000 abstract description 2
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/36—Removing material
- B23K26/38—Removing material by boring or cutting
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/04—Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
- B23K26/046—Automatically focusing the laser beam
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/073—Shaping the laser spot
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/70—Auxiliary operations or equipment
- B23K26/702—Auxiliary equipment
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Abstract
The invention relates to the technical field of laser cutting, in particular to a system and a method for determining a zero focus of a laser cutting head, wherein the system is arranged on the cutting head, a hollow cavity is arranged in the cutting head, a collimating lens and a focusing lens are arranged in the hollow cavity, and a nozzle is arranged at the bottom of the hollow cavity; the system comprises a spectroscope, a hidden box and a CCD device, wherein the spectroscope is arranged between the collimating mirror and the focusing mirror, the hidden box is positioned below the nozzle, a limiting part which can be abutted against the cutting head is arranged on the nozzle, the CCD device is arranged outside the cutting head, light emitted from the laser can reach the focusing mirror through the spectroscope, and light reflected from the nozzle end can reach the CCD device. The invention aims to overcome the defects of the prior art and provide a system for determining the zero focus of a laser cutting head, which can quickly determine the zero focus of the cutting head, has high efficiency and is beneficial to realizing the automation and the intellectualization of the cutting head.
Description
Technical Field
The invention relates to the technical field of laser cutting, in particular to a system and a method for determining a zero focus of a laser cutting head.
Background
The zero focus of the laser cutting head is one of the most important parameters of the cutting head, all process parameters are set based on the zero focus, and the cutting head cannot be used correctly without knowing the zero focus of the cutting head. However, in actual use, due to machining errors, assembly errors and the like of materials, the actual zero focus of each cutting head is different from the theoretical zero focus, which means that the actual zero focus of each cutting head is different. This results in a need to confirm an actual zero focus for each cutting head during actual use.
At present, the method for confirming the zero focus is to use a stainless steel plate with the thickness of 1mm, cut by using different focuses, check the width of the slit, and the focus at the narrowest slit is the zero focus. Although this method can correctly find the zero focus, it is inefficient and not conducive to automation and intelligence of the cutting head.
Chinese patent discloses a zero focus compensation method of intelligent laser cutting head, wherein it is disclosed that the laser cutting head is driven to move up and down by controlling the working of cutting head moving device, mark the steel sheet below the laser cutting head through the laser cutting head, and compare the mark to the facula, when the mark is minimum, namely the facula is thinnest, confirm that the focus is zero focus this moment, but do not specifically disclose how to look for fast and position the position that the facula is thinnest, try cutting through the manual work usually and confirm the zero focus, the efficiency is lower, and be unfavorable for realizing automation and intellectuality of cutting head.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a system for determining the zero focus of a laser cutting head, which can quickly determine the zero focus of the cutting head, has high efficiency and is beneficial to realizing the automation and the intellectualization of the cutting head.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the system for determining the zero focus of the laser cutting head comprises a cutting head, a spectroscope, a cassette and a CCD device, wherein a hollow cavity is arranged in the cutting head, a collimating lens and a focusing lens are arranged in the hollow cavity, and a nozzle is arranged at the bottom of the hollow cavity; the spectroscope is arranged between the collimating mirror and the focusing mirror, the cassette is positioned below the nozzle, the nozzle is provided with a limiting part which can be abutted against the cutting head, the CCD device is arranged at the outer side of the cutting head, light emitted from the laser can reach the focusing mirror through the spectroscope, and light reflected from the nozzle end can reach the CCD device.
The collimating mirror of the present invention is used in a beam delivery system to maintain collimation of a beam between a laser resonator and a focusing optical element; the focusing mirror is used for improving the incidence capacity of the edge light beam and enabling the non-uniform illumination to be homogenized. The nozzle can prevent sundries such as molten spots from rebounding upwards and penetrating through the nozzle to pollute the focusing lens; meanwhile, the gas diffusion area and the size can be controlled, so that the cutting quality is controlled. The system for determining the zero focus of the laser cutting head comprises a spectroscope, a cassette and a CCD device, wherein the cassette is used for positioning the cutting head and facilitating the concentration and reflection of light emitted from a laser; the spectroscope is used for completely transmitting or completely reflecting light emitted from the laser on one hand so that the light reaches the focusing mirror; on the other hand, the light reflected from the nozzle end can be completely reflected or completely transmitted to reach the CCD device; the CCD device is used for photographing to obtain a light spot image, and then the position of a zero focus can be obtained by comparing the size of the light spot image and searching the minimum position of the light spot image. Light emitted from a laser of the cutting machine enters a hollow cavity of the cutting head, is emitted out from a nozzle behind the collimating mirror, the spectroscope and the focusing mirror to reach the cassette, and then is reflected to enter the nozzle to reach the CCD device through the spectroscope to be photographed to obtain a light spot image. The system for determining the zero focus of the laser cutting head can be applied to the cutting head in the prior art, and the function of automatically determining the zero focus of the cutting head is realized.
Because the size of the light spot image can be influenced by different positions of the collimating lens or the focusing lens, the collimating lens or the focusing lens can be selected as a focusing lens in the process of positioning the zero focus, and the position of the zero focus can be determined by changing the position of the focusing lens.
Preferably, the limiting part is a through hole; when the cutting head moves downwards to make the nozzle contact with the through hole, the distance between the end surface of the nozzle and the bottom of the cassette is 1 +/-0.2 mm.
Preferably, the inner walls of the cassette are black.
Preferably, the cutting head is straight tube-shape, the CCD device is installed in the cutting head lateral part, the spectroscope is coated with the film that can totally transmit, collimating mirror and focusing mirror parallel arrangement, the spectroscope slope sets up.
Preferably, the cutting head is of an L-shaped structure, the CCD device is arranged at the top of the cutting head, the spectroscope is coated with a film capable of reflecting completely, the collimating mirror and the focusing mirror are arranged vertically, and the spectroscope is arranged in an inclined manner.
The invention also provides a method for automatically confirming the zero focus of the cutting head, which comprises the following steps:
s1: the cutting head moves downwards to the position where the nozzle is abutted with the position limiting part of the cassette;
s2: turning on a laser red light;
s3: after the focusing lens is well adjusted, a CCD device is used for shooting to obtain a light spot image;
s4: adjusting the focusing lens by a step pitch, and then photographing by using a CCD device to obtain a light spot image;
s5: detecting the number M1 of light spot images, if M1= N1, entering step S6, if M1 is less than N1, returning to step S4, wherein M1 and N1 are positive integers, and N1 is more than or equal to 3;
s6: arranging all the light spot images in sequence along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the light spot images show a rule of changing from big to small and then big; if all the light spot images show a rule of changing from small to big, the step S7 is carried out; if all the light spot images show a rule of changing from big to small, the step S10 is carried out;
s7: adjusting the focusing lens to the positions of the minimum positions of all the light spot images in the photographed image;
s8: adjusting the focusing lens by a step pitch along the reverse direction of the step S3 to the step S4, and then photographing by using a CCD device to obtain a light spot image;
s9: arranging all the spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the spot images show a rule of changing from big to small and then changing into big; if all the spot images show a rule from small to big, returning to the step S8;
s10: adjusting the position of the focusing lens by a step pitch along the direction from the step S3 to the step S4, and then photographing by using a CCD device to obtain a light spot image;
s11: arranging all the spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the spot images show a rule of changing from big to small and then changing into big; if all the spot images show a rule of changing from big to small, returning to the step S10;
s12: determining the position of a zero focus point, and ending the process; wherein the zero focus position is the position of the focusing lens where the spot images in all spot images are minimum.
According to the invention, the focusing lens is adjusted to different positions and then is respectively used for photographing by the CCD device, then the light spot images are compared, the position of the focusing lens is continuously optimized and adjusted by using the imaging rule, and finally the position of the zero focus is positioned.
Further, the step S12 of determining the zero focus position specifically includes the following steps:
s120: determining the position of a focusing lens corresponding to the minimum position of the light spot images in all the light spot images in the photographed process, and adjusting the focusing lens to the position;
s121: taking the minimum position of the light spot image as a center, adjusting the focusing lenses from the two ends of the center by 1/N2 steps along the direction from the step S3 to the step S4 and along the reverse direction from the step S3 to the step S4, and then photographing by using a CCD device to obtain the light spot image, wherein N2 is a positive integer and N2 is more than 1;
s122: arranging the 3 light spot images in sequence along the direction from the step S3 to the step S4, comparing, and entering the step S129 if the light spot images show a rule of changing from big to small and then big; if the three light spot images show a rule from small to large, the step S123 is carried out; if the upper speckle image shows a rule from large to small, step S126 is entered;
s123: adjusting the focusing lens to the position where the 3 facula images are minimum;
s124: adjusting the focusing lens by 1/N2 step pitch along the reverse direction of the step S3 to the step S4, and then photographing by using a CCD device to obtain a light spot image;
s125: arranging all the light spot images formed in the steps 121 to 124 in sequence according to the photographing positions along the directions from the step S3 to the step S4, comparing, and entering the step S129 if all the light spot images show a rule of changing from big to small and then big; if the light spot image shows a rule from small to large, returning to step S124;
s126: adjusting the focusing lens to the position where the 3 facula images are minimum;
s127: adjusting the position of the focusing lens by 1/N2 step pitch along the direction from the step S3 to the step S4, and then photographing by using a CCD device to obtain a light spot image;
s128: arranging all the light spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S129 if all the light spot images show a rule of changing from big to small and then big; if all the spot images show a rule from big to small, returning to the step S127;
s129: determining the position of a zero focus point, and ending the process; wherein the zero focus position is the position of the focusing lens where the spot images are minimum in all the spot images.
Preferably, the step distance is 0.5 mm-10 mm.
Further, in step S9, if all the spot images show a rule of changing from small to large, it is first determined whether the focusing lens is at the limit position, if so, an alarm is output, the process is ended, and if not, the process returns to step S8.
Further, in step S12, if all the spot images exhibit a rule of decreasing from large to small, it is determined whether the focusing lens is at the limit position, and if so, an alarm is output, and the process is ended; if not, the process returns to step S10.
Further, the focusing lens is a collimating lens or a focusing lens.
Compared with the prior art, the invention has the beneficial effects that:
through utilizing the CCD device to shoot with the focusing lens when different positions, arrange in proper order and compare the facula image that different positions gained, can tentatively judge zero focus position, then the position of further adjustment focusing lens to more accurately fix a position zero focus, when the facula image presents the law that diminishes again grow, fix a position out the position that the facula image is minimum is zero focus. The effective combination of quick location and accurate location can be realized to the stride of adopting different in different stages, and the efficiency and the accuracy nature of zero focus location can be promoted to whole method of confirming cutting head zero focus voluntarily, and is favorable to realizing the automation and the intellectuality of cutting head.
Drawings
FIG. 1 is a schematic diagram of a first embodiment of a system for determining a zero focus point of a laser cutting head according to the present invention.
FIG. 2 is a schematic diagram of a second embodiment of a system for determining a zero focus of a laser cutting head according to the present invention.
FIG. 3 is a flow chart of a method for automatically confirming zero focus of a cutting head according to the present invention.
FIG. 4 is a flow chart of a first embodiment of a method for automatically identifying zero focus of a cutting head according to the present invention.
The graphic symbols are illustrated as follows:
1. a cutting head; 2. a nozzle; 3. a beam splitter; 4. a collimating mirror; 5. a focusing mirror; 6. a CCD device; 7. a cassette.
The arrows in fig. 1 and 2 run along the light path.
Detailed Description
The present invention will be further described with reference to the following embodiments. Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, but are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the invention.
Example 1
Fig. 1 shows a first embodiment of a system for determining a zero focus of a laser cutting head according to the present invention, which comprises a cutting head 1, a spectroscope 3, a cassette 7, and a CCD device 9, wherein a hollow cavity is arranged in the cutting head 1, a collimating lens 4 and a focusing lens 5 are arranged in the hollow cavity, and a nozzle 2 is arranged at the bottom of the hollow cavity; spectroscope 3 is installed between collimating mirror 4 and focusing mirror 5, and magazine 7 is located nozzle 2 below, is equipped with the spacing portion that can with cutting head 1 butt on nozzle 2, and CCD device 6 is installed in the cutting head 1 outside, and the light that sends from the laser passes spectroscope 3 can reach focusing mirror 5, and the light that reflects from nozzle 2 end can reach CCD device 6.
The laser penetrates through a hollow cavity of the cutting head 1 and then penetrates out of the nozzle 2, and the collimating mirror 4 is used in a beam transmission system to maintain the collimation of the beam between the laser resonant cavity and the focusing optical element; the focusing mirror 5 has the function of improving the incidence capacity of the marginal beam and enabling the non-uniform illumination to be homogenized. The position of the collimating mirror 4 or the focusing mirror 5 affects the speckle image, so the collimating mirror 4 or the focusing mirror 5 can be used as a focusing lens, and the position of the zero focus can be determined by changing the position of the focusing lens.
Wherein the cutting head 1 is in a straight tube shape. The straight cylindrical structure is a structure of a common cutting head in the industry at present, and the straight cylindrical structure can enable an optical axis of incoming light to be parallel to an optical axis of outgoing light; the CCD device 6 is arranged at the side part of the cutting head 1, the spectroscope 3 is coated with a film capable of transmitting completely, the collimating lens 4 and the focusing lens 5 are arranged in parallel, and the spectroscope 3 is arranged obliquely. As one embodiment, the spectroscope 3 is obliquely disposed at 45 degrees in the hollow cavity. A through hole is provided on the top of the cassette 7, through which the nozzle 2 can be inserted into the cassette 7. The cassette 7 is arranged at a fixed position on the machine tool, the inner wall of the cassette 7 is made into black, when the zero focus needs to be confirmed, the cutting head 1 is moved to the position above the cassette 7, then the cutting head 1 descends until the nozzle 2 contacts with a hole on the cassette 7, and the distance between the section of the nozzle 2 and the surface of the cassette 7 is ensured to be 1mm. The spectroscope 3 is covered with a completely transmissive film. The spectroscope 3 is installed between collimating mirror 4 and the focusing mirror 5 of cutting head 1, and the spectroscope 3 passes through special coating film design, and the light that sends from the laser instrument can reach focusing mirror 5 through passing through spectroscope 3 totally, and the light that sends from nozzle 2 end can reach CCD device 6 by the total reflection.
The cutting head 1 can realize automatic zero focus confirmation, has high automation degree, and is very efficient and convenient.
Example 2
Fig. 2 shows a second embodiment of a system for determining a zero focus of a laser cutting head according to the present invention, which is similar to embodiment 1, except that the cutting head 1 is an L-shaped structure, the CCD device is mounted on the top of the cutting head 1, the spectroscope 3 is coated with a fully reflective film, the collimating mirror 4 and the focusing mirror 5 are vertically disposed, and the spectroscope 3 is obliquely disposed.
The right-angle structure can make the optical axis of the incoming light and the optical axis of the outgoing light form a certain angle, preferably 90 degrees. As one embodiment, the spectroscope 3 is obliquely disposed at 45 degrees in the hollow cavity. Light from the laser is totally reflected by the beam splitter 3 to reach the focusing mirror 5, while light from the nozzle 2 is totally transmitted to reach the CCD device 6.
Example 3
Fig. 3 to 4 show a first embodiment of a method for determining a zero focus of a laser cutting head according to the present invention, which comprises the following steps:
s1: the cutting head 1 moves downwards to the position where the nozzle 2 is abutted with the position limiting part of the cassette 7;
specifically, when the cutting head 1 moves the nozzle 2 downward and abuts against the through hole of the cassette 7, the distance between the end face of the nozzle 2 and the bottom of the cassette 7 is 1mm, and the position is defined as the reference position of the focusing lens;
s2: turning on a laser red light;
red light irradiates the bottom of the cassette 7 through the cutting head 1 to form a red light spot, and the CCD device 6 receives the red light spot through the spectroscope 3;
s3: after the focusing lens is well adjusted, a CCD device 6 is used for photographing to obtain a light spot image, and the focusing lens is a collimating lens 4 or a focusing lens 5;
s4: adjusting the focusing lens by a step pitch, and then photographing by using a CCD device 6 to obtain a light spot image;
s5: detecting the number M1 of light spot images, if M1= N1, entering step S6, if M1 is less than N1, returning to step S4, wherein M1 and N1 are positive integers, and N1 is more than or equal to 3;
as one of the embodiments, N1=11; adjusting the focusing lens every 1mm from +5 to-5 respectively, and shooting the red light spots irradiated at the bottom of the cassette 7 by using the CCD device 6 once when the adjustment is finished; the step distance is 1mm, and the distance between the focusing lens and the two ends of the reference position is within 5 step distances respectively, so that photographing is carried out; after obtaining the light spot images at 11 positions, entering the next step;
s6: arranging all the light spot images in sequence along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the light spot images show a rule of changing from big to small and then big; if all the light spot images show a rule of changing from small to big, the step S7 is carried out; if all the light spot images show a rule of changing from big to small, the step S10 is carried out;
s7: adjusting the focusing lens to the positions of the minimum positions of all the spot images in the photographed image;
the initial judgment is that the zero focus appears in the positive direction except +5, so that the focusing lens is adjusted to + 6- +16;
s8: adjusting the focusing lens by a step pitch along the reverse direction of the step S3 to the step S4, and then photographing by using a CCD device 6 to obtain a light spot image;
adjusting the focusing lens every 1mm from +6 to +16, and shooting the red light spot irradiated at the bottom of the cassette 7 by using the CCD device 6 once when the adjustment is completed; the step distance is still 1mm, and the minimum position of the facula image is continuously searched on the basis of the position from +5 to-5; after obtaining the light spot images at 11 positions, entering the next step;
s9: arranging all the spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the spot images show a rule of changing from big to small and then changing into big; if all the spot images show a rule from small to large, judging whether the focusing lens is in the limit position, if so, outputting an alarm, ending the process, and if not, returning to the step S8;
if the light spot image is still changed from small to large in the range of +6 to +16, the zero focus can be inferred to be in the positive direction farther than +16, at this moment, the focusing lens needs to be adjusted to +17 to +27 once every 1mm, and once adjustment is completed, the CCD device 6 is used for shooting the red light spot irradiated at the bottom of the cassette 7 once; in the cognitive scope of the skilled person, the comparison may be performed not with all the previous spot images, but with only the newly obtained spot image at that position, so as to observe whether the spot image satisfies the rule of first becoming smaller and then becoming larger; and so on; if the focusing lens reaches the limit position, the position of the focusing lens cannot be further adjusted, and even if the zero focus is not found yet, the process can only be ended and an alarm is output;
s10: adjusting the position of the focusing lens by a step pitch along the direction from the step S3 to the step S4, and then photographing by using a CCD device 6 to obtain a light spot image;
adjusting the focusing lens at the position of-6 to-15 every 1mm, and shooting the red light spot irradiated at the bottom of the cassette 7 by using the CCD device 6 once when the adjustment is completed;
s11: arranging all the light spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the light spot images show a rule of becoming smaller and larger; if all the light spot images show a rule of changing from big to small, judging whether the focusing lens is at the extreme position, if so, outputting an alarm, and ending the process; if not, returning to the step S10;
if the obtained light spot image still does not show a rule of changing from big to small and then changing from big to small, but always shows a rule of changing from big to small, the focusing lens is continuously adjusted to a position with a zero focus at a distance of-16 to-26, the focusing lens is adjusted every 1mm, and when the adjustment is finished, the red light spot irradiated at the bottom of the cassette 7 is photographed by using the CCD device 6; and so on; if the focusing lens reaches the limit position, the position of the focusing lens cannot be further adjusted, and even if the zero focus is not found yet, the process can only be ended and an alarm is output;
s12: determining the position of a zero focus point, and ending the process; wherein the zero focus position is the position of the focusing lens where the spot images in all spot images are minimum.
And finding out the minimum position of the light spot images in all the light spot images as a zero focus position.
Example 4
The following is a second embodiment of the method for determining a zero focus of a laser cutting head according to the present invention, which is similar to embodiment 3, except that the step S12 of determining the zero focus position specifically includes the following steps:
s120: determining the position of a focusing lens corresponding to the minimum position of the light spot images in all the shot light spot images, and adjusting the focusing lens to the position;
s121: taking the minimum position of the light spot image as a center, adjusting the focusing lenses from the two ends of the center by 1/N2 steps along the direction from the step S3 to the step S4 and along the reverse direction from the step S3 to the step S4, and then photographing by using a CCD device 6 to obtain the light spot image, wherein N2 is a positive integer, and N2 is more than 1;
s122: arranging the 3 light spot images in sequence along the direction from the step S3 to the step S4, comparing, and entering the step S129 if the light spot images show a rule of changing from big to small and then big; if the three light spot images show a rule from small to large, the step S123 is carried out; if the upper optical spot image shows a rule from big to small, go to step S126;
s123: adjusting the focusing lens to the position where the 3 facula images are minimum;
s124: adjusting the focusing lens by 1/N2 step pitch along the reverse direction of the steps S3 to S4, and then photographing by using a CCD device 6 to obtain a light spot image;
s125: arranging all the light spot images formed in the steps 121 to 124 in sequence according to the photographing positions along the directions from the step S3 to the step S4, comparing, and entering the step S129 if all the light spot images show a rule of changing from big to small and then big; if the light spot image shows a rule of changing from small to large, returning to step S124;
s126: adjusting the focusing lens to the position where the 3 facula images are minimum;
s127: adjusting the position of the focusing lens by 1/N2 step pitch along the direction from the step S3 to the step S4, and then photographing by using a CCD device 6 to obtain a light spot image;
s128: arranging all the spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S129 if all the spot images show a rule of changing from big to small and then changing into big; if all the spot images show a rule of changing from big to small, returning to the step S127;
s129: determining the position of a zero focus point, and ending the process; wherein the zero focus position is the position of the focusing lens where the spot images are minimum in all the spot images.
On the basis of embodiment 1, if at a certain position, for example, at the position with the minimum spot image at +4, since the step pitch is 1mm, the spot images at +5 and +3 are both larger than the spot image at +4, but 1mm is not the minimum step pitch, the step pitch can be refined, the position of the focusing lens is adjusted by taking 0.5mm as the step pitch, and the photographing is respectively performed at +4.5 and +3.5, then the spot images at +4.5, +4 and +3.5 are compared, and the position with the minimum spot image is found to be the zero focus; further, the step pitch is continuously adjusted, the precision is improved, the position of the focusing lens is adjusted by taking 0.2mm or 0.1mm as the step pitch, the photographing is carried out, then the comparison of the light spot images is carried out by the same method, and the minimum position of the light spot image is found to be the zero focus; the specific value of the step pitch can be adjusted according to the required precision, and the higher the precision is, the smaller the step pitch value is, and the more spot images need to be shot.
It should be understood that the above-described 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. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (10)
1. A system for determining a zero focus of a laser cutting head is characterized by comprising a cutting head (1), a spectroscope (3), a dark box (7) and a CCD device (6), wherein a hollow cavity is arranged in the cutting head (1), a collimating lens (4) and a focusing lens (5) are arranged in the hollow cavity, and a nozzle (2) is arranged at the bottom of the hollow cavity; the spectroscope (3) is arranged between the collimating mirror (4) and the focusing mirror (5), the dark box (7) is positioned below the nozzle (7), the nozzle (2) is provided with a limiting part which can be abutted against the cutting head (1), the CCD device (6) is arranged outside the cutting head (1), light emitted from the laser passes through the spectroscope (3) and can reach the focusing mirror (5), and light reflected from the end of the nozzle (2) can reach the CCD device.
2. The system for determining the zero focus of a laser cutting head of claim 1, wherein the limiting portion is a through hole; when the cutting head (1) moves downwards to enable the nozzle (2) to be in contact with the through hole, the distance between the end face of the nozzle (2) and the bottom of the cassette (7) is 1 +/-0.2 mm.
3. System for determining the zero focus of a laser cutting head according to claim 2, characterized in that the inner wall of the cassette (7) is black.
4. A system for determining a zero focus point for a laser cutting head according to any of claims 1 to 3, characterized in that the beam splitter (3) is coated with a fully transmissive film at one end and a fully reflective film at the other end.
5. The system for determining the zero focus of the laser cutting head as claimed in claim 4, wherein the cutting head (1) is in a straight cylinder shape, the CCD device (6) is arranged at the side of the cutting head (1), one end of the spectroscope (3) coated with the film capable of being completely transmitted is placed towards the collimating mirror (4), one end of the spectroscope (3) coated with the film capable of being completely reflected is placed towards the focusing mirror (5), the collimating mirror (4) and the focusing mirror (5) are arranged in parallel, and the spectroscope (3) is arranged in an inclined manner.
6. The system for determining the zero focus of the laser cutting head as claimed in claim 4, wherein the cutting head (1) is of an L-shaped structure, the CCD device (6) is arranged at the top of the cutting head (1), one end of the spectroscope (3) coated with the film capable of being completely reflected is placed towards the collimating mirror (4), one end of the spectroscope (3) coated with the film capable of being completely transmitted is placed towards the focusing mirror (5), the collimating mirror (4) and the focusing mirror (5) are vertically arranged, and the spectroscope (3) is obliquely arranged.
7. A method for determining a zero focus of a laser cutting head is characterized by comprising the following steps:
s1: the cutting head (1) moves downwards to the position where the nozzle (2) is abutted with the limiting part of the cassette (7);
s2: turning on a laser red light;
s3: adjusting the position of a focusing lens, and then photographing by using a CCD device (6) to obtain a light spot image, wherein the focusing lens is a collimating lens (4) or a focusing lens (5);
s4: adjusting the focusing lens by a step pitch, and then photographing by using a CCD device (6) to obtain a light spot image;
s5: detecting the number M1 of light spot images, if M1= N1, entering step S6, if M1 is less than N1, returning to step S4, wherein M1 and N1 are positive integers, and N1 is more than or equal to 3;
s6: arranging all the light spot images in sequence along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the light spot images show a rule of changing from big to small and then big; if all the spot images show a rule from small to big, the step S7 is carried out; if all the spot images show a rule from big to small, the step S10 is carried out;
s7: adjusting the focusing lens to the positions of the minimum positions of all the spot images in the photographed image;
s8: adjusting the focusing lens by a step pitch along the reverse direction of the step S3 to the step S4, and then photographing by using a CCD device (6) to obtain a light spot image;
s9: arranging all the light spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the light spot images show a rule of becoming smaller and larger; if all the light spot images show a rule of changing from small to big, returning to the step S8;
s10: adjusting the position of the focusing lens by a step pitch along the direction from the step S3 to the step S4, and then photographing by using a CCD device (6) to obtain a light spot image;
s11: arranging all the light spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S12 if all the light spot images show a rule of becoming smaller and larger; if all the spot images show a rule of changing from big to small, returning to the step S10;
s12: determining the position of a zero focus point, and ending the process; wherein the zero focus position is the position of the focusing lens where the spot images are minimum in all the spot images.
8. The method of claim 7, wherein the step S12 of determining the zero focus position comprises the steps of:
s120: determining the position of a focusing lens corresponding to the minimum position of the light spot images in all the shot light spot images, and adjusting the focusing lens to the position;
s121: taking the minimum position of the light spot image as a center, adjusting the focusing lenses from the two ends of the center by 1/N2 steps along the direction from the step S3 to the step S4 and along the reverse direction from the step S3 to the step S4, and then photographing by using a CCD device (6) to obtain the light spot image, wherein N2 is a positive integer, and N2 is more than 1;
s122: arranging the 3 light spot images in sequence along the direction from the step S3 to the step S4, comparing, and entering the step S129 if the light spot images show a rule of changing from big to small and then big; if the three light spot images show a rule of changing from small to large, the step S123 is carried out; if the upper optical spot image shows a rule from big to small, go to step S126;
s123: adjusting the focusing lens to the position where the 3 facula images are minimum;
s124: adjusting the focusing lens by 1/N2 step pitch along the reverse direction of the steps S3 to S4, and then photographing by using a CCD device (6) to obtain a light spot image;
s125: arranging all the light spot images formed in the steps 121 to 124 in sequence according to the photographing positions along the directions from the step S3 to the step S4, comparing, and entering the step S129 if all the light spot images show a rule of changing from big to small and then big; if the light spot image shows a rule of changing from small to large, returning to step S124;
s126: adjusting the focusing lens to the position where the 3 facula images are minimum;
s127: adjusting the position of the focusing lens by 1/N2 step pitch along the direction from the step S3 to the step S4, and then photographing by using a CCD device (6) to obtain a light spot image;
s128: arranging all the light spot images formed before the step in sequence according to the photographing positions along the direction from the step S3 to the step S4, comparing, and entering the step S129 if all the light spot images show a rule of changing from big to small and then big; if all the spot images show a rule of changing from big to small, returning to the step S127;
s129: determining the position of a zero focus point, and ending the process; wherein the zero focus position is the position of the focusing lens where the spot images in all spot images are minimum.
9. The method of determining a zero focus for a laser cutting head of claim 8, wherein the step distance is 0.5mm to 10mm.
10. The method for determining the zero focus of the laser cutting head as claimed in claim 1, wherein in step S9, if all the spot images show a rule of changing from small to large, it is determined whether the focusing lens is at the limit position, if yes, an alarm is output, the process is ended, and if no, the process returns to step S8; in the step S12, if all the spot images show a rule from big to small, firstly judging and determining whether the focusing lens is in a limit position, if so, outputting an alarm, and ending the process; if not, the process returns to step S10.
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| CN202210963682.0A CN115138992A (en) | 2022-08-11 | 2022-08-11 | System and method for determining zero focus of laser cutting head |
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20090061138A (en) * | 2007-12-11 | 2009-06-16 | 한국과학기술원 | Auto focusing device and its method |
| CN201693290U (en) * | 2010-04-22 | 2011-01-05 | 广州中国科学院工业技术研究院 | A laser processing device |
| CN105345256A (en) * | 2015-10-09 | 2016-02-24 | 江苏大金激光科技有限公司 | Automatic centering laser cutting head |
| CN106271045A (en) * | 2016-09-05 | 2017-01-04 | 苏州大学 | A kind of automatic focusing adjustor for laser processing, laser process equipment and focus adjustment method |
| CN106767529A (en) * | 2016-12-14 | 2017-05-31 | 深圳奥比中光科技有限公司 | Laser facula identification and the automatic focusing method and system of laser-projector |
| CN109297940A (en) * | 2018-09-06 | 2019-02-01 | 中国科学院沈阳自动化研究所 | A kind of laser defocus amount automatic adjusting device and adjusting method in micron scale |
| CN109884032A (en) * | 2019-02-19 | 2019-06-14 | 中国科学院合肥物质科学研究院 | Laser-induced breakdown spectroscopy detection system and method for precise location of ablation points |
| CN111168230A (en) * | 2020-03-04 | 2020-05-19 | 济南邦德激光股份有限公司 | Focusing device and focusing method of laser cutting machine |
| CN111774723A (en) * | 2020-07-06 | 2020-10-16 | 上海嘉强自动化技术有限公司 | Optical system for detecting zero-focus position of optical fiber laser cutting head |
| CN111940891A (en) * | 2020-07-15 | 2020-11-17 | 大族激光科技产业集团股份有限公司 | Focusing method, system, equipment and storage medium of fiber laser cutting head |
| CN213560635U (en) * | 2020-09-24 | 2021-06-29 | 广东宏石激光技术股份有限公司 | Zero focus correcting unit of laser cutting head |
| CN113740317A (en) * | 2021-08-09 | 2021-12-03 | 合肥金星机电科技发展有限公司 | Laser focusing point position automatic positioning method and system based on spot area |
| CN114578507A (en) * | 2022-02-18 | 2022-06-03 | 电子科技大学 | A real-time laser autofocusing device and method |
-
2022
- 2022-08-11 CN CN202210963682.0A patent/CN115138992A/en active Pending
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20090061138A (en) * | 2007-12-11 | 2009-06-16 | 한국과학기술원 | Auto focusing device and its method |
| CN201693290U (en) * | 2010-04-22 | 2011-01-05 | 广州中国科学院工业技术研究院 | A laser processing device |
| CN105345256A (en) * | 2015-10-09 | 2016-02-24 | 江苏大金激光科技有限公司 | Automatic centering laser cutting head |
| CN106271045A (en) * | 2016-09-05 | 2017-01-04 | 苏州大学 | A kind of automatic focusing adjustor for laser processing, laser process equipment and focus adjustment method |
| CN106767529A (en) * | 2016-12-14 | 2017-05-31 | 深圳奥比中光科技有限公司 | Laser facula identification and the automatic focusing method and system of laser-projector |
| CN109297940A (en) * | 2018-09-06 | 2019-02-01 | 中国科学院沈阳自动化研究所 | A kind of laser defocus amount automatic adjusting device and adjusting method in micron scale |
| CN109884032A (en) * | 2019-02-19 | 2019-06-14 | 中国科学院合肥物质科学研究院 | Laser-induced breakdown spectroscopy detection system and method for precise location of ablation points |
| CN111168230A (en) * | 2020-03-04 | 2020-05-19 | 济南邦德激光股份有限公司 | Focusing device and focusing method of laser cutting machine |
| CN111774723A (en) * | 2020-07-06 | 2020-10-16 | 上海嘉强自动化技术有限公司 | Optical system for detecting zero-focus position of optical fiber laser cutting head |
| CN111940891A (en) * | 2020-07-15 | 2020-11-17 | 大族激光科技产业集团股份有限公司 | Focusing method, system, equipment and storage medium of fiber laser cutting head |
| CN213560635U (en) * | 2020-09-24 | 2021-06-29 | 广东宏石激光技术股份有限公司 | Zero focus correcting unit of laser cutting head |
| CN113740317A (en) * | 2021-08-09 | 2021-12-03 | 合肥金星机电科技发展有限公司 | Laser focusing point position automatic positioning method and system based on spot area |
| CN114578507A (en) * | 2022-02-18 | 2022-06-03 | 电子科技大学 | A real-time laser autofocusing device and method |
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