Method for automatic adjustment of laser spot position

Abstract

The application provides a kind of laser spot position automatic adjusting method, comprising: vision component acquires image, obtains laser spot center initial position and nozzle micro-hole center coordinates, calculates the direction vector and interval of both;Control component drives piezoelectric screw, let spot move a predetermined distance along direction vector, eliminate thread reverse gap, record spot first position;Drive spot to move in the rectangular pixel area that is enclosed by first position and micro-hole center, record spot second position, calibrate the corresponding relationship of displacement sensor value change and image pixel change;Rely on calibration relationship to convert sensor target change required for spot centering, drive piezoelectric screw to carry out adjustment;Real-time monitoring sensor reading, when change meets preset condition, terminate adjustment, realize spot accurate centering.The application can improve the centering accuracy of laser spot and nozzle micro-hole, ensure the stable coupling of laser beam and high-pressure water jet, improve the quality of water guide laser processing.

Description

Technical Field

[0001] This invention relates to the field of water-guided laser processing technology, and in particular to a method for automatically adjusting the position of a laser spot. Background Technology

[0002] Water-guided laser processing is a technology that couples a high-power pulsed laser beam into a water jet, using the micro-water jet to process the workpiece. It boasts advantages such as high processing precision, burr-free operation, wide applicability, and environmental friendliness and efficiency, and has gained widespread attention and application. However, due to assembly tolerances and processing factors, it has been found in practical applications that the laser spot cannot be perfectly aligned with the coupling hole, requiring adjustment of the alignment between the laser spot and the nozzle micro-orifice.

[0003] Existing Chinese patent document CN113787266A (published on December 14, 2021) describes a water-guided laser cutting head structure comprising a laser fiber connector, a beam expander and collimating lens assembly, a beam splitter assembly, a multi-focus lens assembly, a CCD camera adjustment knob, a total reflection mirror assembly, an attenuator assembly, a filter assembly, a CCD camera, a water-light alignment three-coordinate adjustment assembly, and a water-light coupling cavity assembly. The water-light alignment process of this technical solution is as follows: controlling the laser to emit infrared light, fine-tuning the CCD camera adjustment knob until the center of the water jet sapphire nozzle on the CCD camera is at the center of the crosshairs on the CNC system display screen; rotating and adjusting the laser focusing Z-axis adjustment sleeve of the water-light alignment three-coordinate adjustment assembly to align the uppermost focus point among the multiple focus points with the upper plane of the water jet sapphire nozzle, completing the laser focusing adjustment; rotating and adjusting the X-direction and Y-direction alignment adjustment knobs to ensure that the center of the multiple focus points is also at the center of the crosshairs on the CNC system display screen, thus ensuring that the multiple focus points are concentric with the water jet sapphire nozzle.

[0004] The alignment between the laser spot and the nozzle micro-orifice in the existing technology requires a water-optical alignment three-coordinate adjustment component. This adjustment component has a complex structure, and the coupling component moves during the adjustment process. This not only results in slow adjustment efficiency, but also causes the stability of the coupling state to deteriorate due to frequent movement of the coupling component. Summary of the Invention

[0005] The technical problem this invention aims to solve is: how to achieve automated and precise adjustment of the laser spot position. This invention provides a method for automatically adjusting the laser spot position, which can achieve alignment between the laser spot and the nozzle micro-orifice without moving the coupling component, thus achieving coupling between the laser beam and the high-pressure water jet.

[0006] The technical solution adopted by this invention to solve its technical problem is: an automatic laser spot position adjustment method, applied to a water-guided laser processing equipment, the water-guided laser processing equipment including: a mounting base, a laser collimation component, a vision component, and a coupling component; the mounting base is provided with a first optical reflective element and a second optical reflective element; the laser collimation component and the vision component are both connected to the upper end surface of the mounting base; the coupling component is connected to the lower end surface of the mounting base and is coaxially arranged with the vision component; the first optical reflective element is located below the laser collimation component, the second optical reflective element is located below the vision component, the first optical reflective element and the second optical reflective element cooperate to project the laser beam emitted by the laser collimation component into the coupling component; the vision component can monitor the coupling state of the laser beam and the high-pressure water beam; The second optical reflective element can adjust the beam reflection angle through the angle adjustment component so that the center of the laser spot coincides with the center of the nozzle micro-orifice, thereby enabling the laser beam and the high-pressure water beam to achieve a coupling state; the angle adjustment component is connected to the control component by wires, and the angle adjustment component includes: a first piezoelectric screw, a second piezoelectric screw, a first displacement sensor and a second displacement sensor; the first piezoelectric screw and the second piezoelectric screw both abut against the frame of the second optical reflective element; The automatic adjustment method includes: S1. Acquire images of the laser spot and the nozzle micro-orifice through the vision component to obtain the initial position of the laser spot center. and the center coordinates of the nozzle micro-orifice ; Calculate the initial position With center coordinates Direction vectors between and distance ; S2. The control component drives the first piezoelectric screw and the second piezoelectric screw to make the laser spot move along the direction vector. directional movement distance This is done to eliminate the reverse thread clearance of the first and second piezoelectric screws, and the first position of the laser spot center at this time is recorded. ; S3. The control component sends a control signal to the first piezoelectric screw and the second piezoelectric screw, causing the laser spot to be at the first position. Center coordinates of nozzle micro-orifice The rectangular pixel region P1 can be moved in any direction. Record the second position of the laser spot center at this time. And calibrate the correspondence between the numerical changes of the first displacement sensor and the second displacement sensor and the changes in image pixels; S4. Based on the correspondence in step S3, calculate the laser spot position from the second position. Move to the center coordinates of the nozzle orifice The required changes in the first and second displacement sensors are measured; then, the control component drives the first and second piezoelectric screws to move the laser spot toward the nozzle micro-orifice; during the movement of the laser spot, the control component monitors the changes in the values ​​of the first and second displacement sensors in real time, and stops adjusting when the changes in the values ​​of the first and second displacement sensors meet the requirements.

[0007] Furthermore, step S3, calibrating the correspondence between the numerical changes of the first and second displacement sensors and the changes in image pixels, includes: when the laser spot is at the first position... At that time, record the values ​​of the first displacement sensor and the second displacement sensor. When the laser spot moves from the first position Move to the second position Then, record the values ​​of the first and second displacement sensors at this time. ; Obtain the numerical changes of the first displacement sensor and the second displacement sensor. and pixel change ; calibrate the change in the stated value With pixel change The correspondence between them.

[0008] Furthermore, in step S4, the second position is calculated. Center coordinates of nozzle micro-orifice pixel difference between Based on the correspondence in step S3, the numerical changes of the first and second displacement sensors corresponding to the pixel difference are obtained. The control component drives the first piezoelectric screw and the second piezoelectric screw to perform adjustment actions, and reads the numerical changes of the first displacement sensor and the second displacement sensor. When the numerical changes of the first displacement sensor and the second displacement sensor reach ( When the first piezoelectric screw and the second piezoelectric screw are stopped from adjusting, the adjustment action is stopped.

[0009] Furthermore, taking fulcrum O as the origin, the direction of the first piezoelectric screw is... The axis, the direction of the second piezoelectric screw is Axis; let point A be the installation position of the first piezoelectric screw and point B be the installation position of the second piezoelectric screw; let point a be the installation position of the first displacement sensor and point b be the installation position of the second displacement sensor; wherein point a is located on line OA or on the extension of line OA; and point b is located on line OB or on the extension of line OB.

[0010] Furthermore, before executing step S1, it is observed whether the laser spot is within the field of view. If so, step S1 is executed directly; otherwise, the position of the laser spot is pre-adjusted so that the laser spot is within the field of view.

[0011] Furthermore, the position of the laser spot is pre-adjusted, specifically including: adjusting the laser spot along... Distance of movement in the positive direction of the axis Observe whether a laser spot appears within the field of view after movement. If so, stop pre-adjustment; if not, restore the laser spot to its initial position and move it along... Distance of movement in the negative direction of the axis Observe whether a laser spot appears within the field of view after movement. If so, stop pre-adjustment; if not, restore the laser spot to its initial position and move it along... Distance of movement in the positive direction of the axis Observe whether a laser spot appears within the field of view after movement. If so, stop pre-adjustment; if not, restore the laser spot to its initial position and move it along... Distance of movement in the negative direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment.

[0012] Furthermore, record along The positive direction of the axis is 45°, which is direction F. The positive direction of the axis is -45°, which is direction G. Pre-adjusting the position of the laser spot further includes: moving the laser spot a distance along the positive direction F. Observe whether a laser spot appears within the field of view after movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it a distance in the negative direction of F. Observe whether a laser spot appears within the field of view after movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it a distance along the positive direction G. Observe whether a laser spot appears within the field of view after movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it a distance along the negative direction of G. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment.

[0013] Furthermore, in step S2, the laser spot is aligned with the direction vector. directional movement distance Specifically, this includes: the control component sending control signals to the first piezoelectric screw and the second piezoelectric screw, causing the laser spot to move along the direction vector. The laser spot begins to move in the direction of the laser beam; during the movement of the laser spot, the values ​​of the first displacement sensor and the second displacement sensor are observed in real time to see if they change; when the values ​​of both the first displacement sensor and the second displacement sensor change, the control component stops driving the first piezoelectric screw and the second piezoelectric screw.

[0014] Furthermore, the control component can drive the first piezoelectric screw and the second piezoelectric screw in the following ways: the first piezoelectric screw and the second piezoelectric screw are driven alternately, or the first piezoelectric screw and the second piezoelectric screw are driven simultaneously.

[0015] Furthermore, the first displacement sensor is located on the straight line OA, and the line segment The second displacement sensor is located on the straight line OB, and the line segment .

[0016] The beneficial effects of this invention are: This invention acquires the center coordinates of the laser spot and the nozzle micro-orifice through a vision component, calculates the offset direction vector and distance, and provides a basis for precise orientation adjustment. By actively feeding along the offset direction, the backlash of the piezoelectric screw thread is effectively eliminated, avoiding adjustment lag and positioning deviation caused by return backlash. Subsequently, the relationship between displacement and pixels is calibrated within the rectangular pixel area formed by the laser spot and the nozzle micro-orifice, conforming to the actual working field of view and improving calibration accuracy. Finally, the target adjustment amount is accurately solved based on the calibrated correspondence, and closed-loop adjustment is achieved by combining real-time numerical feedback from the displacement sensor, dynamically controlling the laser spot movement stroke. This method effectively offsets mechanical assembly errors and clearance errors, significantly improves the alignment accuracy of the laser spot and the nozzle micro-orifice, ensures the coupling stability of the laser and water jet, and significantly improves the overall processing accuracy and consistency of water-guided laser. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the structure of the water-guided laser processing equipment of the present invention.

[0019] Figure 2 This is a structural schematic diagram of the water-guided laser processing equipment (hidden mounting base) of the present invention.

[0020] Figure 3 This is a three-dimensional schematic diagram of the angle adjustment component of the present invention.

[0021] Figure 4 This is a plan view of the angle adjustment component of the present invention.

[0022] Figure 5 This is the present invention. Figure 4 Sectional view at BB.

[0023] Figure 6 This is a flowchart of the automatic laser spot position adjustment method of the present invention.

[0024] Figure 7 This is a schematic diagram of the mounting point of the angle adjustment component of the present invention.

[0025] Figure 8 This is a schematic diagram of laser spot pre-adjustment according to the present invention.

[0026] Figure 9 This is a schematic diagram of the second position movement according to the present invention.

[0027] Figure 10 This is another schematic diagram of the second position movement of the present invention.

[0028] In the figure: 1. Mounting base; 2. Laser collimation component; 3. Vision component; 4. Coupling component; 5. First optical reflective element; 6. Second optical reflective element; 7. First piezoelectric screw; 8. Second piezoelectric screw; 9. First displacement sensor; 10. Second displacement sensor; 11. Frame. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0030] It should be noted that, as Figures 1 to 5As shown, the water-guided laser processing equipment includes a mounting base 1, a laser collimating component 2, a vision component 3, and a coupling component 4. The mounting base 1 houses a first optical reflecting element 5 (e.g., a mirror) and a second optical reflecting element 6 (e.g., a dichroic mirror). The laser collimating component 2 and the vision component 3 are both connected to the upper surface of the mounting base 1. The coupling component 4 is connected to the lower surface of the mounting base 1 and is coaxially arranged with the vision component 3. The first optical reflecting element 5 is located below the laser collimating component 2, and the second optical reflecting element 6 is located below the vision component 3. The first and second optical reflecting elements 5 and 6 cooperate to project the laser beam emitted by the laser collimating component 2 into the coupling component 4. The vision component 3 can monitor the coupling state between the laser beam and the high-pressure water beam. The second optical reflecting element 6, through an angle adjustment component, can adjust the beam reflection angle so that the center of the laser spot coincides with the center of the nozzle micro-orifice, thereby achieving coupling between the laser beam and the high-pressure water beam. The angle adjustment component is connected to the control component by wires. The angle adjustment component includes: a first piezoelectric screw 7, a second piezoelectric screw 8, a first displacement sensor 9, and a second displacement sensor 10; both the first piezoelectric screw 7 and the second piezoelectric screw 8 abut against the frame 11 of the second optical reflective element 6. The control component drives the first piezoelectric screw 7 and the second piezoelectric screw 8 by sending control signals (e.g., pulse signals). The control component controls the rotation of the drive element inside the piezoelectric screw, causing the push rod to extend or retract. Furthermore, the control component can monitor the real-time readings of the first displacement sensor 9 and the second displacement sensor 10.

[0031] In this embodiment, the first optical reflective element 5 is installed at a fixed angle. When adjusting the angle, only the reflection angle of the second optical reflective element 6 needs to be adjusted. The second optical reflective element 6 is mounted on the frame 11. The first piezoelectric screw 7, the first displacement sensor 9, the second piezoelectric screw 8, and the second position sensor all abut against the bottom surface of the frame 11. The first piezoelectric screw 7, the fulcrum O, and the second piezoelectric screw 8 form an isosceles right triangle. By controlling the feed amount of the first piezoelectric screw 7 and the second piezoelectric screw 8 through the control component, it is possible to... , The reflection angle of the second optical reflective element 6 is adjusted by two degrees of freedom, thereby adjusting the position of the laser spot.

[0032] The purpose of adjusting the laser spot position is to align the center of the laser spot with the center of the nozzle micro-orifice (i.e., the coupling hole). Since the laser spot becomes invisible in the image acquired by the vision component 3 after aligning with the nozzle micro-orifice, the image acquired by the vision component 3 cannot accurately determine the position of the laser spot. Therefore, this embodiment proposes a novel automatic laser spot position adjustment method.

[0033] like Figure 6 As shown, the automatic laser spot position adjustment method of this embodiment includes: S1. Acquire images of the laser spot and the nozzle micro-orifice using the vision component 3 to obtain the initial position of the laser spot center. and the center coordinates of the nozzle micro-orifice ; Calculate the initial position With center coordinates Direction vectors between and distance .

[0034] S2. By controlling the first piezoelectric screw 7 and the second piezoelectric screw 8, the laser spot is driven along the direction vector. directional movement distance This is done to eliminate the reverse thread clearance of the first piezoelectric screw 7 and the second piezoelectric screw 8, and to record the first position of the laser spot center at this time. .

[0035] S3. The control component sends a control signal to the first piezoelectric screw 7 and the second piezoelectric screw 8, causing the laser spot to be positioned at the first position of the component. Center coordinates of nozzle micro-orifice The rectangular pixel region P1 can be moved in any direction. Record the second position of the laser spot center at this time. The correspondence between the numerical changes of the first displacement sensor 9 and the second displacement sensor 10 and the changes in image pixels was calibrated.

[0036] S4. Based on the correspondence in step S3, calculate the laser spot position from the second position of the component. Move to the center coordinates of the nozzle orifice The required changes in the first displacement sensor 9 and the second displacement sensor 10 are measured; then, the first piezoelectric screw 7 and the second piezoelectric screw 8 are driven by the control component to move the laser spot toward the nozzle micro-orifice; during the movement of the laser spot, the control component monitors the changes in the values ​​of the first displacement sensor 9 and the second displacement sensor 10 in real time, and stops adjusting when the changes in the values ​​of the first displacement sensor 9 and the second displacement sensor 10 meet the requirements.

[0037] This embodiment first acquires the center coordinates of the laser spot and the nozzle micro-orifice using the vision component 3, and calculates the offset direction vector and distance to provide a basis for precise orientation adjustment. By actively feeding along the offset direction, the backlash of the piezoelectric screw threads is effectively eliminated, avoiding adjustment lag and positioning deviation caused by return backlash. Subsequently, the relationship between displacement and pixels is calibrated within the rectangular pixel area formed by the laser spot and the nozzle micro-orifice, conforming to the actual working field of view and improving calibration accuracy. Finally, the target adjustment amount is accurately solved based on the calibrated correspondence, and closed-loop adjustment is achieved by combining real-time numerical feedback from the displacement sensor, dynamically controlling the laser spot movement stroke. This method effectively offsets mechanical assembly errors and gap errors, significantly improves the alignment accuracy of the laser spot and the nozzle micro-orifice, ensures the coupling stability of the laser and water jet, and significantly improves the overall processing accuracy and consistency of water-guided laser.

[0038] Specifically, the known center of the laser spot initial position and the center of the nozzle micro-orifice center coordinates The direction vector can be calculated. ,distance In this embodiment (e.g.) Figure 7 As shown), with fulcrum O as the origin, the direction of the first piezoelectric screw 7 is... The axis, the direction of the second piezoelectric screw 8 is Let point A be the installation position of the first piezoelectric screw 7, and point B be the installation position of the second piezoelectric screw 8. Let point a be the installation position of the first displacement sensor 9, and point b be the installation position of the second displacement sensor 10. Point a is located on line OA or its extension; point b is located on line OB or its extension. In other words, the installation position of the first displacement sensor 9 can be on the line connecting the first piezoelectric screw 7 and the fulcrum O, either between the first piezoelectric screw 7 and the fulcrum O or outside of it. Similarly, the installation position of the second displacement sensor 10 can be on the line connecting the second piezoelectric screw 8 and the fulcrum O, either between the second piezoelectric screw 8 and the fulcrum O or outside of it. For ease of installation and assembly, for example, the first displacement sensor 9 can be placed at the midpoint of the line connecting the first piezoelectric screw 7 and the fulcrum O, i.e., the first displacement sensor 9 is located on line OA, and the line segment... The second displacement sensor 10 can be positioned at the midpoint of the line connecting the second piezoelectric screw 8 and the fulcrum O; that is, the second displacement sensor 10 is located on the straight line OB, and the line segment... Of course, in other implementations, the line segment can also be set as... Other proportions, Other proportions.

[0039] It should be noted that the reason for setting up a displacement sensor for real-time monitoring in this embodiment is that if the feed amount of the piezoelectric screw is controlled solely by the pulse signal sent to the piezoelectric screw, errors in the final adjustment result will occur due to factors such as the inaccuracy of the pulse signal. By setting up a displacement sensor for real-time monitoring, the problem of inaccurate feed of the piezoelectric screw itself can be ignored, ensuring that the final displacement result meets the requirements.

[0040] It should be noted that before executing step S1, it is first observed whether the laser spot is within the field of view. If so, step S1 is executed directly; otherwise, the position of the laser spot is pre-adjusted to ensure that the laser spot is within the field of view. Figure 8 As shown, due to factors such as assembly errors, the initial laser spot may be located outside the field of view. In this case, the laser spot cannot be seen in the image acquired by vision component 3; only the nozzle micro-orifice can be seen. Therefore, pre-adjustment is required to bring the laser spot within the field of view so that it can be seen.

[0041] For example, pre-adjusting the position of the laser spot specifically includes: positioning the laser spot along... Distance of movement in the positive direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it along... Distance of movement in the negative direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it along... Distance of movement in the positive direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it along... Distance of movement in the negative direction of the axis Observe whether a laser spot appears within the field of view after movement. If so, stop pre-adjustment. Further, record along... The positive direction of the axis is 45°, which is direction F. The positive axis direction -45° is direction G; pre-adjusting the position of the laser spot also includes: moving the laser spot a distance along the positive direction of F. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it a distance in the negative direction of F. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it a distance along the positive direction G. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment; if not, restore the laser spot to its initial position and move it a distance along the negative direction of G. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment.

[0042] It should be noted that even if the laser spot is outside the field of view, the distance to the boundary of the field of view will not be too far. Therefore, the laser spot can be positioned along... Positive and negative directions of the axis Pre-adjusting is performed in the positive and negative directions of the axis, the positive and negative directions of direction F, and the positive and negative directions of direction G, and the distance of movement is determined. It can be set according to the size of the field of view; for example, the width of the field of view is... Then the distance It can be set to or This embodiment pre-adjusts the laser spot in different directions step by step, traversing the laser spot's offset position level by level, to quickly search for and lock the laser spot within the field of view. By independently adjusting in one direction and resetting and retrying, the laser spot's offset is systematically checked, and the laser spot repositioning preprocessing can be completed quickly. This provides an effective imaging basis for the subsequent alignment, displacement calculation, and precise adjustment of the laser spot with the nozzle micro-orifice, ensuring the smooth progress of the subsequent closed-loop adjustment process of the laser spot position.

[0043] In this embodiment, the position change of the laser spot is achieved by the thread feed of the first piezoelectric screw 7 and the second piezoelectric screw 8. However, when the thread movement direction of the piezoelectric screw changes, there will be a reverse backlash. Therefore, in order to improve the accuracy of the laser spot position movement, it is necessary to eliminate the reverse backlash of the thread. In step S2, the laser spot is moved along the direction vector... directional movement distance Specifically, this includes: sending control signals from the control component to the first piezoelectric screw 7 and the second piezoelectric screw 8, causing the laser spot to move along the direction vector. The direction of the laser spot begins to move; during the movement of the laser spot, the values ​​of the first displacement sensor 9 and the second displacement sensor are observed in real time to see if they change; when the values ​​of both the first displacement sensor 9 and the second displacement sensor change, the control component stops driving the first piezoelectric screw 7 and the second piezoelectric screw 8.

[0044] It should be noted that during the process of eliminating the backlash of the piezoelectric screw, the value of the displacement sensor will not change (because no actual displacement is generated). Based on this condition, this embodiment determines whether the backlash has been eliminated by monitoring the change in the displacement sensor value. Using the change in the displacement sensor value as the trigger criterion, the adjustment lag error caused by the mechanical return backlash of the piezoelectric screw is effectively avoided, improving the accuracy of subsequent laser spot displacement calibration and laying the foundation for high-precision centering adjustment of the laser spot.

[0045] After eliminating the backlash of the piezoelectric screw, the correspondence between the numerical changes of the first displacement sensor 9 and the second displacement sensor 10 and the changes in image pixels can be calibrated. For example... Figure 9 and Figure 10 As shown, the laser spot is positioned at the first position. Center coordinates of nozzle micro-orifice Within the formed rectangular pixel region P1, in any direction (preferably along the direction vector) (Direction) Movement distance Record the second position of the laser spot center at this time. Among them, distance + distance distance For example, distance It can be set as distance The percentages, such as 20% and 60%, are not specifically limited here. It should be noted that since both the first piezoelectric screw 7 and the second piezoelectric screw 8 abut against the frame 11, when one piezoelectric screw is advanced, the other piezoelectric screw will cause a slight displacement of the frame 11 even if it is not advanced. Therefore, to improve adjustment accuracy, the control component drives the first piezoelectric screw 7 and the second piezoelectric screw 8 in two ways: alternatingly driving the first piezoelectric screw 7 and the second piezoelectric screw 8, or driving the first piezoelectric screw 7 and the second piezoelectric screw 8 simultaneously. Therefore, the calibrated correspondence is the relationship between the numerical changes of the first displacement sensor 9 and the second displacement sensor 10 and the changes in image pixels, rather than the correspondence between a single displacement sensor and a pixel.

[0046] The specific calibration process is as follows: when the laser spot is in the first position At that time, the values ​​of the first displacement sensor 9 and the second displacement sensor 10 are recorded. When the laser spot moves from the first position Move to the second position Then, record the values ​​of the first displacement sensor 9 and the second displacement sensor 10 at this time. ; Obtain the numerical changes of the first displacement sensor 9 and the second displacement sensor 10. and pixel change ; Change in calibration value With pixel change The correspondence between them is established. By collecting the displacement sensor readings corresponding to the first and second positions of the laser spot, the changes in the two displacement sensor values ​​and the changes in image pixels are calculated, and a mapping relationship between the two is established. Based on the correspondence obtained from actual measurements, the conversion of pixel deviation into displacement sensor adjustment can be accurately realized, reducing the system error in the conversion process, providing a reliable conversion basis for subsequent closed-loop centering adjustment of the laser spot, and effectively improving the positioning and centering accuracy of the laser spot and the nozzle micro-orifice.

[0047] After establishing the correspondence, calculate the second position. Center coordinates of nozzle micro-orifice pixel difference between Based on the correspondence in step S3, the numerical change of the first displacement sensor 9 and the second displacement sensor 10 corresponding to the pixel difference is obtained. The control unit drives the first piezoelectric screw 7 and the second piezoelectric screw 8 to perform adjustment actions, and reads the numerical changes of the first displacement sensor 9 and the second displacement sensor 10. When the numerical changes of the first displacement sensor 9 and the second displacement sensor 10 reach ( When the first piezoelectric screw 7 and the second piezoelectric screw 8 are stopped from adjusting, the adjustment action is stopped.

[0048] This embodiment relies on a pre-calibrated correspondence between displacement sensor changes and pixel changes to convert the pixel deviation between the laser spot and the nozzle micro-orifice into a target change in displacement sensor readings. The control unit drives the piezoelectric screw for adjustment and reads the displacement sensor feedback data in real time. The change in displacement sensor value is used as the criterion for stopping adjustment, forming a complete closed-loop control. This eliminates the lag problem of relying solely on visual image judgment, reduces the risk of misjudgment caused by image noise interference, precisely controls the adjustment stroke, effectively improves the positioning accuracy of laser spot alignment, and ensures efficient coupling between the laser beam and the water jet.

[0049] In summary, the automatic laser spot position adjustment method of the present invention obtains the center coordinates of the laser spot and the nozzle micro-orifice through the vision component 3, calculates the offset direction vector and distance, and provides a basis for precise orientation adjustment. By actively feeding along the offset direction, the backlash of the piezoelectric screw thread is effectively eliminated, avoiding adjustment lag and positioning deviation caused by the return backlash. Subsequently, the relationship between displacement and pixels is calibrated within the rectangular pixel area formed by the laser spot and the nozzle micro-orifice, conforming to the actual working field of view and improving calibration accuracy. Finally, the target adjustment amount is accurately solved based on the calibrated correspondence, and closed-loop adjustment is achieved by combining real-time numerical feedback from the displacement sensor, dynamically controlling the laser spot movement stroke. This method effectively offsets mechanical assembly errors and gap errors, significantly improves the alignment accuracy of the laser spot and the nozzle micro-orifice, ensures the coupling stability of the laser and water jet, and significantly improves the overall processing accuracy and consistency of water-guided laser.

[0050] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for automatically adjusting the position of a laser spot, applied to a water-guided laser processing equipment, characterized in that, The water-guided laser processing equipment includes: a mounting base, a laser collimation component, a vision component, and a coupling component. The mounting base houses a first optical reflecting element and a second optical reflecting element. The laser collimation component and the vision component are both connected to the upper surface of the mounting base. The coupling component is connected to the lower surface of the mounting base and is coaxially arranged with the vision component. The first optical reflecting element is located below the laser collimation component, and the second optical reflecting element is located below the vision component. The first and second optical reflecting elements cooperate to project the laser beam emitted by the laser collimation component into the coupling component. The vision component can monitor the coupling state between the laser beam and the high-pressure water jet. The second optical reflective element can adjust the beam reflection angle through the angle adjustment component so that the center of the laser spot coincides with the center of the nozzle micro-orifice, thereby enabling the laser beam and the high-pressure water beam to achieve a coupling state; the angle adjustment component is connected to the control component by wires, and the angle adjustment component includes: a first piezoelectric screw, a second piezoelectric screw, a first displacement sensor and a second displacement sensor; the first piezoelectric screw and the second piezoelectric screw both abut against the frame of the second optical reflective element; The automatic adjustment method includes: S1. Acquire images of the laser spot and the nozzle micro-orifice through the vision component to obtain the initial position of the laser spot center. and the center coordinates of the nozzle micro-orifice ; Calculate the initial position With center coordinates Direction vectors between and distance ; S2. The control component drives the first piezoelectric screw and the second piezoelectric screw to make the laser spot move along the direction vector. directional movement distance This is done to eliminate the reverse thread clearance of the first and second piezoelectric screws, and the first position of the laser spot center at this time is recorded. ; S3. The control component sends a control signal to the first piezoelectric screw and the second piezoelectric screw, causing the laser spot to be at the first position. Center coordinates of nozzle micro-orifice The rectangular pixel region P1 can be moved in any direction. Record the second position of the laser spot center at this time. And calibrate the correspondence between the numerical changes of the first displacement sensor and the second displacement sensor and the changes in image pixels; S4. Based on the correspondence in step S3, calculate the laser spot position from the second position. Move to the center coordinates of the nozzle orifice The required changes in the first and second displacement sensors are measured; then, the control component drives the first and second piezoelectric screws to move the laser spot toward the nozzle micro-orifice; during the movement of the laser spot, the control component monitors the changes in the values ​​of the first and second displacement sensors in real time, and stops adjusting when the changes in the values ​​of the first and second displacement sensors meet the requirements.

2. The automatic laser spot position adjustment method as described in claim 1, characterized in that, Step S3, calibrating the correspondence between the numerical changes of the first and second displacement sensors and the changes in image pixels, includes: When the laser spot is in the first position At that time, record the values ​​of the first displacement sensor and the second displacement sensor. ; When the laser spot moves from the first position Move to the second position Then, record the values ​​of the first and second displacement sensors at this time. ; Obtain the numerical changes of the first displacement sensor and the second displacement sensor. and pixel change ; Calibrate the change in the value With pixel change The correspondence between them.

3. The automatic laser spot position adjustment method as described in claim 2, characterized in that, In step S4, the second position is calculated. Center coordinates of nozzle micro-orifice pixel difference between Based on the correspondence in step S3, the numerical changes of the first and second displacement sensors corresponding to the pixel difference are obtained. ; The control component drives the first piezoelectric screw and the second piezoelectric screw to perform adjustment actions, and reads the numerical changes of the first displacement sensor and the second displacement sensor. When the numerical changes of the first displacement sensor and the second displacement sensor reach ( When the first piezoelectric screw and the second piezoelectric screw are stopped from adjusting, the adjustment action is stopped.

4. The automatic laser spot position adjustment method as described in claim 1, characterized in that, With fulcrum O as the origin, the direction of the first piezoelectric screw is... The axis, the direction of the second piezoelectric screw is Axis; let point A be the installation position of the first piezoelectric screw and point B be the installation position of the second piezoelectric screw; let point a be the installation position of the first displacement sensor and point b be the installation position of the second displacement sensor; wherein point a is located on line OA or on the extension of line OA; and point b is located on line OB or on the extension of line OB.

5. The automatic laser spot position adjustment method as described in claim 1, characterized in that, Before executing step S1, observe whether the laser spot is within the field of view. If it is, execute step S1 directly; otherwise, pre-adjust the position of the laser spot so that it is within the field of view.

6. The automatic laser spot position adjustment method as described in claim 5, characterized in that, Pre-adjusting the position of the laser spot specifically includes: The laser spot along Distance of movement in the positive direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment. If not, then restore the laser spot to its initial position and along... Distance of movement in the negative direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment. If not, then restore the laser spot to its initial position and along... Distance of movement in the positive direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment. If not, then restore the laser spot to its initial position and along... Distance of movement in the negative direction of the axis Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment.

7. The automatic laser spot position adjustment method as described in claim 6, characterized in that, Record along The positive direction of the axis is 45°, which is direction F. The positive direction of the axis is -45°, which is direction G. Pre-adjusting the position of the laser spot further includes: The laser spot is moved a distance along the positive direction F. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment. If not, then restore the laser spot to its initial position and move it a distance along the negative direction F. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment. If not, then restore the laser spot to its initial position and move it a distance along the positive direction G. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment. If not, then restore the laser spot to its initial position and move it a distance along the negative direction of G. Observe whether a laser spot appears within the field of view after the movement. If so, stop the pre-adjustment.

8. The automatic laser spot position adjustment method as described in claim 1, characterized in that, In step S2, the laser spot is aligned with the direction vector. directional movement distance Specifically, it includes: The control component sends control signals to the first piezoelectric screw and the second piezoelectric screw, causing the laser spot to move along the direction vector. The laser spot begins to move in the direction of the laser beam; during the movement of the laser spot, the values ​​of the first displacement sensor and the second displacement sensor are observed in real time to see if they change. When the values ​​of both the first displacement sensor and the second displacement sensor change, the control component stops driving the first piezoelectric screw and the second piezoelectric screw.

9. The automatic laser spot position adjustment method as described in claim 1, characterized in that, The control component drives the first piezoelectric screw and the second piezoelectric screw in the following ways: the first piezoelectric screw and the second piezoelectric screw are driven alternately, and the first piezoelectric screw and the second piezoelectric screw are driven simultaneously.

10. The automatic laser spot position adjustment method as described in claim 4, characterized in that, The first displacement sensor is located on the straight line OA, and the line segment ; The second displacement sensor is located on the straight line OB, and the line segment .

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