Automatic focusing and plate positioning device of laser plate cutting machine based on machine vision

Abstract

The invention discloses a laser plate cutting machine automatic focusing and plate positioning device based on machine vision, and relates to the field of laser cutting devices. The laser plate cutting machine automatic focusing and plate positioning device based on machine vision comprises a laser cutting head used for emitting a laser beam to cut a plate, and further comprises a rack, a vision detection module and a control system. According to the laser plate cutting machine automatic focusing and plate positioning device based on machine vision, visual feature point images on a plate are collected in real time through the visual detection module fixed to the laser cutting head, the control system calculates the deviation between the actual position and the theoretical position according to the visual feature point images, and the subsequent cutting path of the laser cutting head is dynamically corrected; the problem of path deviation caused by plate positioning errors and thermal deformation in the machining process is effectively solved, and the dimensional precision and notch quality of a final workpiece are improved.

Description

Technical Field

[0001] This invention relates to the field of laser cutting equipment technology, specifically to an automatic focusing and plate positioning device for a laser plate cutting machine based on machine vision. Background Technology

[0002] Laser cutting technology is widely used in modern manufacturing for processing both metal and non-metal sheets. Traditional laser cutting machines typically rely on preset digital programs to control the cutting path and use mechanical positioning or simple photoelectric sensors for sheet alignment.

[0003] In actual processing, positioning errors may occur during the feeding of the sheet metal, and deformation and displacement may occur during cutting due to factors such as thermal deformation and stress release, resulting in deviations between the preset cutting path and the actual position of the sheet metal. This deviation directly causes the dimensional deviation of the processed workpiece to exceed tolerances, the quality of the cut to decrease, or even scrapping, especially in high-precision processing applications. To solve these problems, existing technologies typically employ manual intervention correction or offline visual inspection. Manual correction is inefficient and relies on operator experience, while offline inspection cannot handle real-time deformation during cutting. Equipment often uses a global camera for initial positioning, which cannot achieve continuous tracking and real-time compensation during cutting. Moreover, in actual operation, it has been found that the smoke and splatter generated during cutting easily contaminate the vision lens, affecting image quality and causing positioning failure. Therefore, to address the shortcomings of existing technologies, this invention provides an automatic focusing and sheet metal positioning device for laser cutting machines based on machine vision to solve the above problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an automatic focusing and plate positioning device for laser cutting machines based on machine vision. By using a vision detection module fixed to the laser cutting head to collect images of visual feature points on the plate in real time, the control system calculates the deviation between the actual position and the theoretical position and dynamically corrects the subsequent cutting path of the laser cutting head. This effectively overcomes the path deviation problems caused by plate positioning errors and thermal deformation during processing, and improves the dimensional accuracy and cut quality of the final workpiece.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an automatic focusing and plate positioning device for a laser plate cutting machine based on machine vision, comprising a laser cutting head for emitting a laser beam to cut the plate, the device further comprising:

[0006] A frame is provided with an XYZ axis movement control module for supporting the laser cutting head, and a positioning platform for placing the plate is provided on the frame.

[0007] A visual inspection module is fixedly installed on the laser cutting head and is used to acquire images of visual feature points on the board in real time during the cutting process;

[0008] The control system is connected to the laser cutting head and the vision inspection module via signals respectively, and the control system is configured as follows:

[0009] Based on the images acquired by the visual detection module, the actual positions of the visual feature points are calculated in real time.

[0010] The actual position is compared with the preset theoretical position to generate position deviation data;

[0011] And based on the position deviation data, the subsequent cutting path of the laser cutting head is dynamically corrected.

[0012] Preferably, the visual inspection module includes a high-speed local camera and a matching coaxial light source. The optical axis of the high-speed local camera forms a fixed angle θ with the optical axis of the laser beam of the laser cutting head, so that the focal area of ​​the field of view of the high-speed local camera is located at the laser focal point of the laser cutting head.

[0013] Preferably, the visual inspection module further includes a protective air curtain assembly, which is arranged around the lens of the high-speed local camera and is used to continuously blow clean compressed gas into the field of view in front of the lens to form an air curtain that isolates cutting smoke and splashes.

[0014] Preferably, the protective air curtain assembly includes an annular cover and an annular air chamber communicating with the annular cover. The annular air chamber is connected to an external air source through an air inlet pipe, and the coaxial light source can be installed inside the annular cover.

[0015] Preferably, the visual feature points include positioning marks pre-made on the plate before cutting and cutting contour features formed during the cutting process.

[0016] Preferably, the control system includes an image processing unit and a path planning unit;

[0017] The image processing unit is configured to use a multi-scale template matching and sub-pixel localization algorithm to identify and accurately locate the localization mark or cutting contour feature;

[0018] The path planning unit is configured to perform real-time translation and rotation compensation on the cutting path segments that have not yet been executed, based on the precise positioning results output by the image processing unit.

[0019] Preferably, the device further includes an integrated ranging module mounted on the laser cutting head. The integrated ranging module is signal-connected to the control system and is used to measure the distance between the laser cutting head and the surface of the plate in real time, and to provide real-time focus compensation data to the control system.

[0020] Preferably, the integrated ranging module is a laser displacement sensor, and the ranging spot of the laser displacement sensor is adjacent to the projection position of the field of view focal area of ​​the vision detection module on the surface of the plate.

[0021] Preferably, the device further includes a global positioning camera fixed on the frame, the global positioning camera being signal-connected to the control system for capturing a full-view image of the board material before cutting begins, in order to perform initial position calibration.

[0022] Preferably, the control system is further configured to: integrate the initial position calibration data provided by the global positioning camera and the real-time position deviation data provided by the vision detection module to jointly generate a final comprehensive compensation control command for the laser cutting head.

[0023] The technical effects and advantages of this invention are as follows:

[0024] 1. This machine vision-based laser cutting machine's automatic focusing and plate positioning device acquires real-time images of visual feature points on the plate through a vision detection module fixed to the laser cutting head. The control system calculates the deviation between the actual and theoretical positions based on these images and dynamically corrects the subsequent cutting path of the laser cutting head. This effectively overcomes the path deviation problems caused by plate positioning errors and thermal deformation during processing, thereby improving the dimensional accuracy and cut quality of the final workpiece.

[0025] 2. This machine vision-based laser cutting machine's automatic focusing and plate positioning device uses a protective air curtain component to continuously blow clean compressed gas to form an isolation air curtain in front of the high-speed local camera lens. This effectively blocks the smoke and metal spatter generated during the cutting process. The protective air curtain component ensures that the vision inspection module can still obtain clear and stable images in harsh processing environments, thus providing a reliable data foundation for accurate positioning and further improving the long-term operational stability and service life of the entire system in industrial environments.

[0026] 3. This machine vision-based laser cutting machine's automatic focusing and plate positioning device provides real-time focusing compensation data through an integrated ranging module. This data is then fused with planar position deviation data provided by a vision inspection module and initial calibration data provided by a global positioning camera. The control system can generate comprehensive compensation control commands, enabling the laser cutting head to not only be accurately positioned in the XY plane but also maintain optimal focusing in the Z-axis direction. This achieves all-round precise control in three-dimensional space, making it particularly suitable for processing plates with uneven surfaces or thin plates. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the optical axis of the high-speed local camera and laser cutting head of the present invention;

[0030] Figure 3 This is a schematic diagram of the visual feature points and ranging spot of the present invention;

[0031] Figure 4 This is a three-dimensional structural diagram of the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of the protective air curtain assembly of the present invention;

[0033] Figure 6 This is a schematic diagram of the integrated ranging module of the present invention;

[0034] Figure 7 This is a cross-sectional schematic diagram of the annular cover of the present invention;

[0035] Figure 8 This is a disassembly diagram of the annular cover of the present invention;

[0036] Figure 9 This is a schematic diagram of the structure of the plate material of the present invention;

[0037] Figure 10 This is a logic diagram of image processing and path correction in the control system of the present invention;

[0038] Figure 11 This is a data flow diagram for the integrated positioning and focusing of this invention.

[0039] In the diagram: 1. Laser cutting head; 2. Vision inspection module; 21. High-speed local camera; 22. Coaxial light source; 3. Control system; 31. Image processing unit; 32. Path planning unit; 4. Protective air curtain assembly; 41. Annular cover; 42. Annular air chamber; 43. Air inlet pipe; 5. Integrated ranging module; 51. Ranging spot; 6. Global positioning camera; 7. Frame; 71. XYZ axis movement control module; 8. Positioning stage; 9. Sheet metal; 91. Positioning mark; 92. Cutting contour features. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] This embodiment discloses an automatic focusing and plate positioning device for a laser cutting machine based on machine vision, according to the attached... Figure 1 To be continued Figure 11 As shown, the device includes a laser cutting head 1 for emitting a laser beam to cut a sheet metal 9, a frame 7, a vision inspection module 2, and a control system 3. The frame 7 serves as the mounting base for the device, and an XYZ axis movement control module 71 is integrated on its top. The laser cutting head 1 is fixedly mounted on the execution end of the XYZ axis movement control module 71 via a flange structure, enabling precise movement in the X, Y, and Z directions under the control of the control system 3. A positioning platform 8 is welded and fixed in the middle of the frame 7. The surface of the positioning platform 8 is covered with an anti-slip rubber pad to stably place the sheet metal 9 to be cut, and the flatness error of the platform 8 is controlled within 0.02 mm / m to ensure the reference accuracy of the sheet metal 9 after placement.

[0042] According to the appendix Figure 1 Appendix Figure 2 As shown, the vision inspection module 2 is further fixedly installed on the side wall of the laser cutting head 1 by a customized bracket bolt, remaining relatively stationary with the laser cutting head 1, and can move synchronously with the laser cutting head 1, thereby acquiring images of visual feature points on the plate 9 in real time during the cutting process. The vision inspection module 2 includes a high-speed local camera 21 and a matching coaxial light source 22. The high-speed local camera 21 is an industrial camera with a resolution of 2048×1536 pixels and a frame rate of 100fps. Its optical axis forms a fixed angle θ with the laser beam optical axis of the laser cutting head 1. In this embodiment, θ is set to 45°. The lens parameters are determined through optical simulation calculations so that the diameter of the field of view focal area of ​​the high-speed local camera 21 is controlled within 5mm and is exactly located at the laser focal point position of the laser cutting head 1, achieving precise correspondence between vision inspection and cutting position.

[0043] According to the appendix Figure 5 Appendix Figure 7 Appendix Figure 8 As shown, the visual inspection module 2 further includes a protective air curtain assembly 4 to address the issue of smoke and splashes contaminating the camera lens during the cutting process. The protective air curtain assembly 4 surrounds the lens of the high-speed local camera 21 and includes an annular cover 41, an annular air chamber 42, and an air inlet pipe 43. The annular cover 41 is made of aluminum alloy and is connected to the lens support of the high-speed local camera 21 via a customized bracket. It has a recessed groove for mounting a coaxial light source 22, which uses a ring-shaped LED structure and is connected to the power module of the control system 3 via wires. The annular air chamber 42 is integrally formed inside the annular cover 41 and has a trapezoidal cross-section. The top of the annular air chamber 42 is connected to the air inlet pipe 43 via a quick-connect connector. The other end of the air inlet pipe 43 is connected to an external air compressor. During operation, the air compressor provides clean compressed gas at 0.4 MPa, forming a uniform annular air curtain through the outlet of the annular air chamber 42. The air curtain covers an area 10 mm beyond the camera's field of view, effectively isolating cutting smoke and splashes.

[0044] According to the appendix Figure 1 To be continued Figure 3 Appendix Figure 9 As shown, the visual feature points specifically disclosed include positioning marks 91 pre-made on the plate 9 before cutting and cutting contour features 92 formed during the cutting process. The positioning marks 91 are made at the four corners of the plate 9 using a laser marking machine. The mark shape is "cross", the line width is 0.2mm, and the intersection of the cross is the precise positioning reference. The cutting contour features 92 include the straight edges and arc contours that have been cut, which are automatically extracted by the image processing unit 31. The control system 3 includes an image processing unit 31 and a path planning unit 32. The image processing unit 31 adopts an FPGA-based image processing board and is equipped with multi-scale template matching and sub-pixel positioning algorithms. In the template matching process, a 1 / 4 scale is first used for fast coarse matching, and then the original scale is used for precise matching, with a matching accuracy of 1 pixel. Sub-pixel positioning is achieved by Gaussian curve fitting, which improves the positioning accuracy to the 0.01 pixel level. The path planning unit 32 adopts an industrial PC equipped with a motion control card. Based on the precise positioning results output by the image processing unit 31, it performs real-time translation and rotation compensation on the cutting path segments that have not yet been executed through a homogeneous coordinate transformation algorithm, with a compensation response time of less than 10ms.

[0045] According to the appendix Figure 1 Appendix Figure 6 Appendix Figure 11As shown, the device also includes an integrated ranging module 5 mounted on the laser cutting head 1 for automatic focusing. The integrated ranging module 5 uses a laser displacement sensor with a measurement range of 50-200mm and a measurement accuracy of ±0.01mm. It is fixed to the side of the laser cutting head 1 by a bracket. The ranging spot 51 of the laser displacement sensor and the projection position of the focal area of ​​the vision detection module 2 onto the surface of the plate 9 are adjacent, with a distance controlled within 3mm to ensure that they measure the height information of the same area. The integrated ranging module 5 is connected to the control system 3 via an RS485 bus to measure the distance between the laser cutting head 1 and the surface of the plate 9 in real time, and provides real-time focusing compensation data to the control system 3. Based on this data, the control system 3 controls the Z-axis actuator of the XYZ-axis movement control module 71 to adjust the height of the laser cutting head 1, ensuring that the laser focus always falls on the surface of the plate 9.

[0046] According to the appendix Figure 1 Appendix Figure 9 Appendix Figure 11 As shown, it is particularly important to emphasize that the device also includes a global positioning camera 6 fixed on the frame 7, used for initial position calibration before cutting. The global positioning camera 6 is an area array industrial camera with a resolution of 5472×3648 pixels, equipped with an 8mm fixed-focus lens, and fixed to the top of the frame 7 via a gantry structure. Its field of view can cover the entire table surface of the positioning table 8. The global positioning camera 6 is connected to the control system 3 via gigabit Ethernet. Before cutting begins, it captures a full-view image of the plate 9. After the image processing unit 31 performs distortion correction and grayscale processing on the image, it identifies the positioning marks 91 at the four corners of the plate 9, calculates the deviation between the actual placement position of the plate 9 and the preset reference position, and completes the initial position calibration.

[0047] According to the appendix Figure 10 Appendix Figure 11 As shown, it is particularly important to emphasize that the control system 3 adopts a hierarchical control architecture. The bottom layer is the motion control layer, responsible for controlling the start and stop of the XYZ axis movement control module 71 and the laser cutting head 1. The middle layer is the data processing layer, including the image processing unit 31 and the ranging data processing unit, which process visual data and ranging data respectively. The top layer is the decision layer, responsible for fusing the initial position calibration data provided by the global positioning camera 6 and the real-time position deviation data provided by the visual detection module 2. The fusion process uses the Kalman filter algorithm to perform weighted fusion of the two types of data. In the initial stage, the weight of the global positioning data is 0.7. As the cutting process progresses, the weight of the real-time position deviation data gradually increases to 0.9, ultimately generating the final comprehensive compensation control command for the laser cutting head 1, ensuring a balance between positioning accuracy and dynamic response performance.

[0048] Example 1: This example uses a 2mm thick stainless steel sheet cut into 9mm sections as an example, combined with the attached...Figure 1 To be continued Figure 11 Detailed explanation of the workflow: The workflow is as follows:

[0049] 1. Preparation stage: Place the stainless steel sheet 9 to be cut on the positioning table 8 and roughly align it manually; start the device, the control system 3 initializes each module, the global positioning camera 6 takes a full-view image of the sheet 9, identifies the four corner positioning marks 91, calculates that the sheet 9 has a deviation of 5mm in the X direction, 3mm in the Y direction, and 1.2° in rotation, completes the initial position calibration, and sends the calibration data to the path planning unit 32.

[0050] 2. Focusing and calibration: The integrated ranging module 5 is activated and emits a ranging spot 51 onto the surface of the plate 9 to measure the distance between the laser cutting head 1 and the surface of the plate 9 in real time. The measured data is 120mm, which is consistent with the preset 120mm reference distance, so no focusing adjustment is required. If there is a deviation, the control system 3 controls the Z-axis actuator to adjust the height of the laser cutting head 1.

[0051] 3. Cutting Start: The control system 3 makes preliminary corrections to the preset cutting path based on the initial position calibration data, controls the laser cutting head 1 to start the laser and begin cutting; at the same time, the high-speed local camera 21 and coaxial light source 22 of the vision detection module 2 are activated, and the protective air curtain assembly 4 starts supplying air to form an annular air curtain.

[0052] 4. Real-time correction: During the cutting process, the high-speed local camera 21 acquires images at a frame rate of 100fps, and the image processing unit 31 identifies the cutting contour features 92 formed by the cutting and calculates the real-time position deviation. When the cutting reaches the middle of the plate 9, an X-axis deviation of 0.3mm and a Y-axis deviation of 0.2mm are detected. The path planning unit 32 performs fusion compensation based on the initial calibration data and controls the XYZ axis movement control module 71 to adjust the cutting path.

[0053] 5. Cutting complete: After the laser cutting head 1 completes all cutting paths, the laser is turned off, and the air curtain assembly continues to supply air for 5 seconds to remove residual smoke and dust; the global positioning camera 6 takes another picture to check the overall positional accuracy of the cut part. The positioning accuracy of this cut is ±0.05mm, which meets the process requirements.

[0054] Example 2: This example uses the cutting of a thin aluminum sheet with a thickness of 0.5mm as an example, combined with the attached... Figure 1 To be continued Figure 11 Detailed explanation of the workflow: The workflow is as follows:

[0055] 1. Preparation stage: Place the thin aluminum sheet 9 on the positioning stage 8. Since the aluminum sheet 9 is thin, vacuum suction cups are used to assist in fixing it on the positioning stage 8. The global positioning camera 6 takes a full view image, identifies the positioning mark 91, and finds that the sheet 9 has a deviation of 2mm in the X direction and 1.5mm in the Y direction, with no obvious rotational deviation, thus completing the initial calibration.

[0056] 2. Focusing calibration: The integrated ranging module 5 measures the distance between the laser cutting head 1 and the surface of the plate 9 to be 110mm. The preset reference distance is 110mm. However, considering the possible slight deformation of the thin plate 9, the control system 3 controls the laser cutting head 1 to move slightly along the Z-axis, collects ranging data from multiple points, and completes focusing after determining the average height.

[0057] 3. Cutting Start-up: The laser cutting head 1 is started, and a lower 500W laser power is used for cutting. The vision inspection module 2 focuses on identifying the positioning mark 91 and the initial cutting contour features 92. Since there is less smoke and dust from cutting the thin plate 9, the air curtain pressure is adjusted to 0.3MPa.

[0058] 4. Real-time correction: During the cutting process, a slight thermal deformation was found in the thin plate 9, resulting in a deviation of 0.15mm in the Y direction. The image processing unit 31 accurately captured the deviation through sub-pixel positioning, and the path planning unit 32 compensated in real time to avoid the cutting trajectory from deviating.

[0059] 5. Cutting Completed: After cutting, the vacuum suction cup is released, and the cut part is removed; the inspection shows that the cutting accuracy is ±0.03mm, which meets the cutting requirements for electronic component housings.

[0060] In summary, this device uses the vision detection module 2 to acquire real-time images of visual feature points on the board 9, and the control system 3 to calculate the deviation between the actual and theoretical positions and correct the cutting path. Combined with the precise drive of the XYZ axis movement control module 71, it completely solves the problem of traditional mechanical positioning being unable to handle placement deviations and cutting deformations in the board 9. Compared to existing technologies, it improves positioning accuracy and has a faster response time, enabling real-time compensation for dynamic deviations during the cutting process and significantly improving cutting quality.

[0061] The device integrates the visual inspection module 2 with the integrated ranging module 5. The ranging module collects the distance between the laser cutting head 1 and the surface of the plate 9 in real time, providing focus compensation data. Furthermore, the ranging spot 51 is adjacent to the visual focus area, ensuring consistency between the detection and focusing positions. This design overcomes the limitations of traditional fixed-focus or manual focusing methods that cannot adapt to different thicknesses of plates 9 and uneven surfaces. It can accommodate plates 9 with thicknesses ranging from 0.1 to 10 mm, achieving a focusing accuracy of ±0.01 mm, effectively avoiding problems such as incomplete or over-cutting. Simultaneously, the device forms a ring-shaped air curtain through the protective air curtain assembly 4 to isolate smoke and dust. Combined with the dual detection of the high-speed local camera 21 and the global positioning camera 6, it solves the problems of susceptibility to contamination and limited field of view associated with single-vision inspection. The entire process achieves automated control from initial calibration, automatic focusing, real-time correction, to completion of cutting inspection, eliminating the need for manual calibration and adjustment.

[0062] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A machine vision-based automatic focusing and plate positioning device for a laser plate cutting machine, comprising a laser cutting head (1) for emitting a laser beam to cut a plate (9), characterized in that: The device also comprises: a rack (7) provided with an XYZ axis movement control module (71) for carrying the laser cutting head (1), and a positioning table (8) for placing the plate (9) on the rack (7); a visual detection module (2) fixedly installed on the laser cutting head (1) for collecting images of visual feature points on the plate (9) in real time during the cutting process; a control system (3) signal connected with the laser cutting head (1) and the visual detection module (2), respectively, and configured to: calculate the actual positions of the visual feature points in real time based on the images collected by the visual detection module (2); compare the actual positions with preset theoretical positions to generate position deviation data; and dynamically correct the subsequent cutting path of the laser cutting head (1) according to the position deviation data.

2. The automatic focusing and plate positioning device based on machine vision for a laser plate cutting machine according to claim 1, characterized in that, The visual detection module (2) comprises a high-speed local camera (21) and a coaxial light source (22) matched therewith, and the optical axis of the high-speed local camera (21) forms a fixed angle θ with the laser beam optical axis of the laser cutting head (1), so that the visual field focal point area of the high-speed local camera (21) is located at the laser focal point position of the laser cutting head (1).

3. The automatic focusing and plate positioning device based on machine vision for laser plate cutting machine according to claim 2, characterized in that, The visual detection module (2) further comprises a protective gas curtain assembly (4) arranged around the lens of the high-speed local camera (21) for continuously blowing clean compressed gas to the visual field area in front of the lens to form a gas curtain for isolating cutting smoke and splashing.

4. The automatic focusing and plate positioning device based on machine vision for the laser plate cutting machine according to claim 3, characterized in that, The protective gas curtain assembly (4) comprises a ring-shaped cover (41) and a ring-shaped air cavity (42) in communication with the ring-shaped cover (41), the ring-shaped air cavity (42) is connected with an external gas source through a gas inlet pipe (43), and the coaxial light source (22) can be installed inside the ring-shaped cover (41).

5. The automatic focusing and plate positioning device based on machine vision for laser plate cutting machine according to claim 2, characterized in that, The visual feature points include positioning marks (91) made on the plate (9) before cutting and cutting contour features (92) formed during the cutting process.

6. The automatic focusing and plate positioning device based on machine vision for laser plate cutting machine according to claim 5, characterized in that, The control system (3) comprises an image processing unit (31) and a path planning unit (32); The image processing unit (31) is configured to use a multi-scale template matching and sub-pixel positioning algorithm to identify and accurately position the positioning marks (91) or cutting contour features (92); The path planning unit (32) is configured to perform real-time translation and rotation compensation on the cutting path segment that has not been executed based on the accurate positioning result output by the image processing unit (31).

7. The automatic focusing and plate positioning device based on machine vision for laser plate cutting machine according to claim 1, wherein, The device further comprises an integrated distance measuring module (5) installed on the laser cutting head (1), which is signal connected with the control system (3) for measuring the distance between the laser cutting head (1) and the surface of the plate (9) in real time and providing real-time focusing compensation data to the control system (3).

8. The automatic focusing and plate positioning device based on machine vision for laser plate cutting machine according to claim 7, characterized in that, The integrated distance measuring module (5) is a laser displacement sensor, and a distance measuring spot (51) of the laser displacement sensor is adjacent to a projection position of a field of view focal point area of the visual detection module (2) on a surface of the plate (9).

9. The automatic focusing and plate positioning device based on machine vision for laser plate cutting machine according to claim 1, characterized in that, The device further comprises a global positioning camera (6) fixed on the rack (7), which is signal connected with the control system (3) and used for shooting a full-view image of the plate (9) before cutting starts, so as to perform initial position calibration.

10. The automatic focusing and plate positioning device based on machine vision for a laser plate cutting machine according to claim 9, wherein, The control system (3) is further configured to fuse initial position calibration data provided by the global positioning camera (6) and real-time position deviation data provided by the visual detection module (2), and jointly generate a final comprehensive compensation control instruction for the laser cutting head (1).

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