A welding tongs straightening device based on machine vision

Abstract

The present application relates to a kind of based on machine vision's welding tongs straightening device, including vision camera, visual detection system and data monitoring platform;Vision camera sends the image photographed to image processing module;Data analysis module processes image;Data processing module exports data transmission to data monitoring platform and provides monitoring data, judges whether welding tongs need straightening;Still include welding tongs straightening device can be clamped and synchronous correction welding tongs.The present application monitors welding tongs coaxality by machine vision, combines with actual production condition and sends real-time data to unified monitoring platform, realizes welding tongs automatic detection, perfects the quality monitoring of welding process, and has certain contribution to improve welding quality and production line intelligentization, provides data basis for subsequent welding tongs straightening.A kind of straightening device is designed, improves the efficiency of welding tongs straightening;Clamping roller needle also plays the limiting effect to welding tongs, solves the problem of poor fixing effect when straightening, inconvenient straightening adjustment and thus reduces work efficiency.

Description

Technical Field

[0001] This invention belongs to the field of robotic welding technology, specifically relating to a welding clamp straightening device based on machine vision. Background Technology

[0002] In robotic welding applications, resistance spot welding is a welding method in which the workpiece to be welded is pressed between the two electrodes of the spot welding clamp and an electric current is passed through it. The resistance heat generated by the current flowing through the contact surface and adjacent areas of the workpiece heats the electrode contact area on the workpiece to a melting or plastic state, thereby forming a metal bond.

[0003] Electrode alignment directly affects the electrode contact state and current distribution during welding, and is the most important factor in determining the weld nugget position. Good electrode alignment results in minimal offset, allowing for the application of greater electrode force to constrain the weld nugget and prevent welding defects. Therefore, to obtain weld nuggets with uniform size, high strength, and a clean surface, it is generally necessary to ensure the welding clamp electrodes are vertically aligned. This not only reduces welding quality defects but also allows for the timely detection and repair of potential faults, ensuring the normal operation of the production line.

[0004] The coaxiality of the welding clamp is very important. It is necessary to judge whether there is any deviation in the coaxiality of the welding clamp. The common method is manual inspection. After a certain number of welding operations, workers will stop the machine for maintenance. This method is inefficient, has poor accuracy, and is easily affected by human factors. Summary of the Invention

[0005] The purpose of this invention is to provide a machine vision-based welding clamp straightening device to solve the problem of timely straightening of electrode rod deformation during welding. Integrating machine vision into welding clamp inspection enables timely straightening of electrode rod deformation during welding, preventing electrode misalignment caused by deformation and thus ensuring the quality of spot welding.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A machine vision-based welding clamp straightening device includes a vision camera, a vision inspection system, and a data monitoring platform;

[0008] The visual inspection system consists of an image processing module, a data analysis module, and a data processing module. The visual camera is connected to the image processing module and sends the captured images to the image processing module. The image processing module is connected to the data analysis module to process the images. The data processing module is connected to the data analysis module and exports the data to the data monitoring platform to provide monitoring data and determine whether the welding clamp needs to be straightened.

[0009] It also includes a welding clamp straightening device, which consists of a mounting plate, two sets of linear movement mechanisms and two sets of clamping mechanisms; the two sets of linear movement mechanisms are symmetrically mounted on the mounting plate, and each clamping mechanism is mounted on a linear module slide on the corresponding linear movement mechanism.

[0010] The linear motion mechanism is a linear servo module; each clamping mechanism consists of a hydraulic cylinder mounting base, a bidirectional hydraulic cylinder, a linear servo module, a roller fork, and a clamping roller; the bidirectional hydraulic cylinder is connected to the hydraulic cylinder mounting base; the roller fork is connected to the hydraulic rod of the bidirectional hydraulic cylinder, the cylindrical part of the roller fork is connected to the hydraulic rod, and the end of the roller fork is connected to the clamping roller; the clamping roller is used for synchronously straightening the welding clamp.

[0011] The data monitoring platform is used to monitor the centering, perpendicularity, and position of the welding clamp during operation and feeds the data back to the vision inspection system. After receiving the visual image, the vision inspection system will use an algorithm to generate the position and angle data that need to be straightened and transmit the data to the welding clamp straightening device driver through the data monitoring platform. The driver will drive the linear movement mechanism and clamping mechanism to move according to the position and angle data to achieve the straightening work.

[0012] Furthermore, the vision camera is placed at the welding robot's workstation, and the welding clamp remains within the camera's field of view throughout the welding process; the vision inspection system is based on an open-source computer vision library and uses Hough transform to extract features.

[0013] Furthermore, the mounting plate is an integral structure, consisting of an upper mounting plate and a lower bracket welded together; the lower bracket is welded together from square steel pipes, with reinforcing ribs welded on it and mounting holes at the bottom, and is fixed to the ground with anchor bolts.

[0014] Furthermore, both the mounting plate and the linear motion mechanism have threaded holes, and the linear motion mechanism is fixed to the mounting plate by bolts.

[0015] Furthermore, the linear module slide of the linear movement mechanism has threaded holes for connecting the clamping mechanism.

[0016] Furthermore, the hydraulic cylinder mounting base is a U-shaped block with threaded holes at the bottom and ends.

[0017] Furthermore, the bidirectional hydraulic cylinder is a bidirectional hydraulic cylinder with a displacement sensor installed at the tail, and the bidirectional hydraulic cylinder is connected to the hydraulic cylinder mounting base through the bottom mounting hole.

[0018] Furthermore, the cylindrical portion of the roller fork has a threaded hole for connecting a hydraulic rod, and the U-shaped structure at the end of the roller fork has a U-shaped groove for connecting a clamping roller.

[0019] Furthermore, the axial cross-section of the clamping roller is a concave semicircle, and two clamping rollers can form a circle, thereby fitting the cylindrical surface of the electrode rod; the clamping roller bearing is equipped with a cylindrical roller bearing, and the roller and bearing are fixed to the roller spindle by roller end caps and hexagonal thin nuts; the roller spindle is threaded at both ends and connected to the roller fork by nuts.

[0020] Furthermore, there are at least two clamping rollers, two together as a group, and multiple groups of clamping rollers are arranged longitudinally along the mounting plate to synchronously correct the welding clamps.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. This invention monitors the coaxiality of welding guns using machine vision and sends real-time data to a unified monitoring platform in conjunction with actual production conditions. This achieves automated detection of welding guns, improves quality monitoring of the welding process, and contributes to improving welding quality and production line intelligence. It also provides a data foundation for subsequent welding gun straightening and designs a welding gun straightening device to address the coaxiality problem of welding guns.

[0023] 2. Based on visual detection of the welding clamp coaxiality problem, a straightening device was designed to address this issue. A hydraulic cylinder was chosen as the power source. Due to its compact structure, the same volume and weight can transmit greater power. Hydraulic power can convert electrical power into greater kinetic energy than electricity. Furthermore, a linear servo module was designed to enable linear movement of the clamping rollers, facilitating welding clamp positioning and saving time during the preparation and post-straightening stages. Through simple and efficient movement, the straightening efficiency of the welding clamps is improved. The clamping rollers also act as a limit for the welding clamps, solving the problems of poor fixation and inconvenient straightening adjustments that reduce work efficiency during straightening. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a block diagram of the visual inspection system of the present invention;

[0026] Figure 2 This is a schematic diagram of the straightening device of the present invention;

[0027] Figure 3 This is a schematic diagram of the clamping mechanism of the straightening device of the present invention;

[0028] Figure 4 This is a cross-sectional view of the pressing roller structure of the present invention;

[0029] In the diagram: 1. Vision camera 2. Image processing module 3. Data analysis module 4. Data processing module 5. Data monitoring platform 6. Lower support 7. Mounting plate 8. Linear movement mechanism 9. Clamping mechanism 10. Linear module slide 11. Hydraulic cylinder mounting base 12. Bidirectional hydraulic cylinder 13. Clamping roller 14. Roller 15. Roller spindle 16. Hexagonal thin nut 17. Roller end cap 18. Roller fork. Detailed Implementation

[0030] The present invention will be further described below with reference to embodiments:

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0032] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] This invention combines machine vision inspection technology with a straightening device. The machine vision-assisted technology enables non-contact, fast, stable, and high-precision online measurement of the workpiece, while the straightening device is used to correct the welding clamp.

[0034] This invention relates to a machine vision-based welding clamp straightening device, comprising a vision camera 1, a vision inspection system, and a data monitoring platform 5. The data monitoring platform 5 monitors the alignment, perpendicularity, and position of the welding clamp during operation and feeds the data back to the vision inspection system. Upon receiving the visual image, the vision inspection system uses an algorithm to generate data such as the position and angle requiring straightening, and transmits this data from the data monitoring platform 5 to the welding clamp straightening device driver. The driver then drives the linear movement mechanism 8 and the clamping mechanism 9 to move according to the position and angle data, thereby achieving the straightening operation.

[0035] The visual inspection system consists of an image processing module 2, a data analysis module 3, and a data processing module 4.

[0036] The vision camera 1 is placed at the welding robot's workstation, and the welding clamp remains within the camera's field of view throughout the welding process. The vision camera 1 is connected to the vision inspection system, providing visual images. The vision inspection system includes an image processing module 2 connected to a data analysis module 3 to process the images. Since the actual welding clamp needs to monitor various data, a data processing module 4 is designed to connect to the data analysis module 3, subsequently exporting and transmitting the data to the data monitoring platform 5.

[0037] Specifically, the vision camera 1 is connected to the image processing module 2, and sends the captured images to the vision inspection system. To meet the requirements of fast processing and real-time performance, the vision inspection system is based on the open-source computer vision library (OpenCV) and uses Hough transform to extract features. The data processing module 4 processes the data and exports it into the source files required by the data monitoring platform 5, ensuring data synchronization, real-time monitoring, providing monitoring data, and determining whether the welding clamp needs straightening.

[0038] The present invention relates to a welding clamp straightening device based on machine vision, which further includes a welding clamp straightening device, wherein the welding clamp straightening device consists of a mounting plate 7, two sets of linear movement mechanisms 8 and two sets of clamping mechanisms 9.

[0039] The mounting plate 7 is an integral structure, consisting of an upper mounting plate and a lower bracket 6 welded together. The lower bracket 6 is made of square steel pipe welded together, with reinforcing ribs welded on it and mounting holes at the bottom, and is fixed to the ground with anchor bolts.

[0040] The two sets of linear movement mechanisms 8 are mounted on the mounting plate 7, and each clamping mechanism 9 is mounted on the linear module slide 10 on the corresponding linear movement mechanism 8.

[0041] Specifically, both the mounting plate 7 and the linear motion mechanism 8 have threaded holes, and the linear motion mechanism 8 is fixed to the mounting plate 7 by bolts. The linear motion mechanism 8 is a linear servo module, and two linear motion mechanisms 8 are symmetrically arranged on the mounting plate 7. The linear module slide 10 of the linear motion mechanism 8 has threaded holes for connecting the clamping mechanism 9.

[0042] Each clamping mechanism 9 consists of a hydraulic cylinder mounting base 11, a bidirectional hydraulic cylinder 12, a roller fork 18, and a clamping roller 13.

[0043] The hydraulic cylinder mounting base 11 is a U-shaped block with threaded holes at the bottom and ends.

[0044] The bidirectional hydraulic cylinder 12 is connected to the hydraulic cylinder mounting base 11. The bidirectional hydraulic cylinder 12 is a bidirectional hydraulic cylinder with a displacement sensor at the tail, and is connected to the hydraulic cylinder mounting base 11 through the bottom mounting hole.

[0045] The roller fork 18 is connected to the hydraulic rod of the bidirectional hydraulic cylinder 12. The cylindrical part of the roller fork 18 has a threaded hole for connecting the hydraulic rod, and the U-shaped structure at the end of the roller fork 18 has a U-shaped groove for connecting the clamping roller 13.

[0046] The clamping roller 13 has a concave semi-circular axial cross-section, and two clamping rollers 13 can form a circle, thus fitting against the cylindrical surface of the electrode rod. The clamping roller 13's bearing contains cylindrical roller bearings, and the roller 14 and bearing of the clamping roller 13 are fixed to the roller spindle 15 by roller end caps 17 and hexagonal thin nuts 16. The roller spindle 15 has threads at both ends, which are connected to the roller fork 18 by nuts.

[0047] The clamping rollers 13 are at least two, two together, and multiple sets of clamping rollers 13 are arranged longitudinally along the mounting plate to synchronously correct the welding clamps.

[0048] Example 1

[0049] A welding clamp straightening device based on machine vision consists of a vision camera 1, a vision inspection system, a data monitoring platform 5, and a welding clamp straightening device.

[0050] The vision camera 1 is positioned at the welding robot's workstation and its position and angle are set to ensure that the welding clamp does not leave the camera's capture range during the welding process. The vision camera 1 is connected to the image processing module 2 in the vision inspection system. The processing includes image reading, image cropping, noise reduction, Hough transform, and other methods. The processed image is analyzed by the data analysis module 3 to determine the coaxiality of the welding clamp. Since welding is a complex process, its data is usually monitored on a unified platform. In this embodiment, the data processing module 4 processes the vision inspection results and exports them as an adaptation file, which is then directly read by the data monitoring platform 5.

[0051] Specifically, the image is read by the vision camera 1 and sent to the vision detection system. After cropping out the excess image, the image is optimized by the median filtering method, which can not only remove noise but also retain boundary information.

[0052] Specifically, based on the characteristics of the welding clamp and the detection target, Hough transform is used to detect straight lines, transforming lines in the image space into points in the parameter space. Then, a voting method is used to find the peak value, and the detection problem is solved by estimating the parameters.

[0053] Specifically, the data processing module 4 is connected to the data monitoring platform 5 to ensure that monitoring data is provided in real time and to determine whether the welding clamp needs to be straightened.

[0054] like Figures 2-4 As shown, the welding clamp straightening device consists of a mounting plate 7, two sets of linear movement mechanisms 8, and two sets of clamping mechanisms 9.

[0055] The mounting plate 7 is an integral structure, consisting of an upper mounting plate and a lower bracket 6. The upper mounting plate is welded onto the lower bracket 6, and its height limit covers the working range of the welding clamp. The lower bracket 6 is welded from a square steel tube, and the bracket 6 has reinforcing ribs and mounting holes at the bottom, and is fixed to the ground with anchor bolts.

[0056] The two sets of linear movement mechanisms 8 are linear servo modules, symmetrically mounted on the mounting plate 7, and the linear module slide 10 of the linear movement mechanism 8 is connected to the clamping mechanism 9 by bolts.

[0057] The linear motion mechanism 8 is fixed to the mounting plate 7 by bolts. The linear motion mechanism 8 is a linear servo module.

[0058] Each clamping mechanism 9 consists of a hydraulic cylinder mounting base 11, a bidirectional hydraulic cylinder 12, a linear servo module, a roller fork 18, and a clamping roller. The hydraulic cylinder mounting base 11 is a U-shaped block with threaded holes at the bottom and ends.

[0059] The cylinder body of the bidirectional hydraulic cylinder 12 is threadedly connected to the linear module slide 10 of the linear movement mechanism 8. The bidirectional hydraulic cylinder 12 is a bidirectional hydraulic cylinder with a displacement sensor at its tail, and is connected to the hydraulic cylinder mounting base 11 through a bottom mounting hole. The clamping mechanism 9 relies on the left and right extension and retraction of the bidirectional hydraulic cylinder 12 to control the retraction of the two clamping rollers 13, adjusts and controls the insertion and release of the welding clamp, and adjusts the clamping force during operation.

[0060] There are two or more clamping rollers 13, with two forming a group. Multiple groups of clamping rollers are arranged longitudinally along the mounting plate to simultaneously correct the welding clamps.

[0061] The axial cross-section of the clamping roller 13 is a concave semicircle, and two clamping rollers 13 can form a circle, thereby fitting the cylindrical surface of the electrode rod.

[0062] The clamping roller 13 has a cylindrical roller bearing inside. The roller 14 and the bearing are fixed to the roller spindle 15 by the roller end cap 17 and the hexagonal thin nut 16. The roller spindle 15 has threads at both ends and is connected to the roller fork 18 by the hexagonal thin nut 16.

[0063] The cylindrical portion of the roller fork 18 has a threaded hole for connecting the hydraulic rod of the bidirectional hydraulic cylinder 12, and the U-shaped structure of the roller fork 18 has a U-shaped groove for connecting the clamping roller 13.

[0064] The roller fork 18 is connected to a clamping roller 13 on one side, and the welding clamp is straightened by the two clamping rollers 13.

[0065] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A welding clamp straightening device based on machine vision, characterized in that: Includes a visual camera (1), a visual inspection system, and a data monitoring platform (5); The visual inspection system consists of an image processing module (2), a data analysis module (3), and a data processing module (4); the visual camera (1) is connected to the image processing module (2) and sends the captured image to the image processing module (2); the image processing module (2) is connected to the data analysis module (3) to process the image; the data processing module (4) is connected to the data analysis module (3); the data is exported and transmitted to the data monitoring platform (5) to provide monitoring data and determine whether the welding clamp needs to be straightened; It also includes a welding clamp straightening device, which consists of a mounting plate (7), two sets of linear movement mechanisms (8) and two sets of clamping mechanisms (9); the two sets of linear movement mechanisms (8) are symmetrically mounted on the mounting plate (7), and each clamping mechanism (9) is mounted on a linear module slide (10) on the corresponding linear movement mechanism (8); The linear movement mechanism (8) is a linear servo module; each clamping mechanism (9) consists of a hydraulic cylinder mounting base (11), a bidirectional hydraulic cylinder (12), a linear servo module, a roller fork (18), and a clamping roller (13); the bidirectional hydraulic cylinder (12) is connected to the hydraulic cylinder mounting base (11); the roller fork (18) is connected to the hydraulic rod of the bidirectional hydraulic cylinder (12), the cylindrical part of the roller fork (18) is connected to the hydraulic rod, and the end of the roller fork (18) is connected to the clamping roller (13); the clamping roller (13) is used for synchronously straightening the welding clamp; The data monitoring platform (5) is used to monitor the centering, verticality and position of the welding clamp during the working process, and feed the data back to the vision inspection system. After receiving the visual image, the vision inspection system will use an algorithm to form the position and angle data that need to be straightened, and transmit the data to the welding clamp straightening device driver by the data monitoring platform (5). The driver will drive the linear movement mechanism (8) and the clamping mechanism (9) to move according to the position and angle data to realize the straightening work. The vision camera (1) is placed at the welding robot's workstation, and the welding clamp is always within the camera's field of view during the welding process; the vision inspection system is based on an open-source computer vision library and uses Hough transform to extract features; the mounting plate (7) is an integral structure, consisting of an upper mounting plate and a lower bracket (6) welded together; the lower bracket (6) is welded together from square steel pipes, with reinforcing ribs welded on it and mounting holes at the bottom, and is fixed to the ground with anchor bolts; both the mounting plate (7) and the linear motion mechanism (8) have threaded holes, and the linear motion mechanism (8) is fixed to the mounting plate (7) with bolts; the linear module slide (10) of the linear motion mechanism (8) has threaded holes for connecting the clamping mechanism (9); the hydraulic cylinder mounting base (11) is a U-shaped block with threaded holes at the bottom and end; the bidirectional hydraulic cylinder (12) has a displacement sensor mounted at the tail. The bidirectional hydraulic cylinder (12) is connected to the hydraulic cylinder mounting base (11) through the bottom mounting hole; the cylindrical part of the roller fork (18) has a threaded hole for connecting the hydraulic rod, and the U-shaped structure at the end of the roller fork (18) has a U-shaped groove for connecting the clamping roller (13); the outer contour of the axial section of the clamping roller (13) is a concave semicircle, and two clamping rollers (13) can form a circle, thereby fitting the cylindrical surface of the electrode rod; the bearing of the clamping roller (13) is equipped with a cylindrical roller bearing, and the roller (14) and the bearing are fixed on the roller spindle (15) through the roller end cap (17) and the hexagonal thin nut (16); the roller spindle (15) has threads at both ends, which are connected to the roller fork (18) by nuts; there are at least two clamping rollers (13), two as a group, and multiple groups of clamping rollers (13) are arranged longitudinally along the mounting plate to synchronously correct the welding clamp.

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