Metal pipe welding robot control system

Abstract

The invention relates to the technical field of metal pipe welding, in particular to a metal pipe welding robot control system which comprises an acquisition module, a control module and a control module. The judgment module is used for judging whether the difference value is qualified; the determining module is used for determining the welding type; the regulation and control module is used for regulating and controlling welding parameters according to the weld joint characteristic parameters obtained in real time; the evaluation module is used for evaluating the welding quality; the analysis module is used for analyzing and determining the adjustment coefficient of the welding parameters; and the adjusting module is used for adjusting the welding parameters for the first time according to the adjusting coefficient, and determining to continue to perform secondary adjustment on the welding parameters or perform adjustment on the positive and negative angle adjusting coefficient according to the welding quality variation before and after the first adjustment. According to the actual metal pipe welding angle and the actual welding gap condition, the welding parameters are adjusted for the first time and the second time or the positive and negative angle adjustment coefficient is adjusted, and the metal pipe welding quality is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal pipe welding, in particular to a metal pipe welding robot control system. BACKGROUND

[0002] In the metal processing and manufacturing industry, automatic welding technology as an important part of modern manufacturing greatly improves production efficiency and welding quality. Among them, metal pipe welding is a crucial process link, especially when welding metal pipes at multiple angles, the accuracy of controlling the welding process directly affects the quality of welding and the consistency of the weld.

[0003] The patent document with publication number CN115990696A discloses a liner pipe welding control circuit, a welding device and a welding control method. The method includes: sampling the initial current of the liner pipe to obtain a sample current value; obtaining the current difference value between the sample current value and the standard current value, and outputting the initial PID control parameter according to the current difference value; adjusting the initial current according to the initial PID control parameter, so that the adjusted current has a constant pulse waveform; obtaining a speed control signal according to the standard speed, and controlling the welding gun to rotate at a preset speed according to the speed control signal to weld the liner pipe; obtaining the pulse signal generated by the Hall sensor in the brushless reduction motor of the welding gun; outputting a rotation attribute control signal according to the pulse signal; controlling the rotation position and / or rotation angle of the welding gun according to the rotation attribute control signal.

[0004] In the prior art, the metal pipe welding process is often controlled by a single process control method, so that in the control process, the welding parameters cannot be adjusted once and the welding parameters cannot be adjusted twice or the positive and negative angle adjustment coefficients cannot be adjusted according to the actual metal pipe welding angle and welding gap, resulting in low metal pipe welding quality in different situations. SUMMARY

[0005] Therefore, the present application provides a metal pipe welding robot control system to solve the technical problem that in the prior art, the metal pipe welding process is often controlled by a single process control method, so that in the control process, the welding parameters cannot be adjusted once and the welding parameters cannot be adjusted twice or the positive and negative angle adjustment coefficients cannot be adjusted according to the actual metal pipe welding angle and welding gap, resulting in low metal pipe welding quality in different situations.

[0006] To achieve the above purpose, the present application provides a metal pipe welding robot control system, comprising: The acquisition module is used to acquire the first to-be-welded section angle, the second to-be-welded section angle, the position of the to-be-welded metal pipe, the pipe outer diameter and the pipe wall thickness, and real-time acquisition of the weld characteristic parameters; the weld characteristic parameters include the weld length, the weld width and the weld depth; The judgment module is connected with the acquisition module and is used to judge whether the difference between the sum of the first to-be-welded section angle and the second to-be-welded section angle and the target angle is qualified according to the standard positive and negative angle threshold range; The determination module is connected with the judgment module and is used to determine the welding type according to the comparison result of the difference and the preset ideal positive and negative angle; the preset ideal positive and negative angle is the product of the standard positive and negative angle and a positive and negative angle adjustment coefficient, the positive and negative angle adjustment coefficient takes a value between 0 and 1, and the welding type includes constant welding and variable welding; The regulation module is connected with the determination module and is used to regulate the welding parameters of the welding robot performing the welding action according to the welding type and the real-time acquired weld characteristic parameters; The evaluation module is connected with the regulation module and is used to evaluate the welding quality in combination with the welding surface flatness qualified rate, the welding line continuity qualified rate and the welding part completeness qualified rate; The analysis module is connected with the evaluation module and is used to determine the adjustment coefficient of the welding parameters according to the welding quality; The adjustment module is connected with the analysis module and is used to adjust the welding parameters once according to the adjustment coefficient, and to determine whether to continue to adjust the welding parameters twice or to adjust the positive and negative angle adjustment coefficient according to the welding quality change amount before and after the first adjustment.

[0007] Further, a positioning mechanism is further included and is used to position the to-be-welded metal pipe and the to-be-welded section; the positioning mechanism includes a fixed station and a moving station, wherein, The fixed station includes a base, a circular rotating disc is arranged at the center position of the surface of the base, the circular rotating disc is connected with the base through a center shaft and a metal pipe limiting device is arranged on the circular rotating disc, so as to limit and fix the first to-be-welded metal pipe on the circular rotating disc; the circular rotating disc is rotatable and the rotation angle is 0-360°, so as to adjust the position of the first to-be-welded metal pipe; at least two fixed support columns are arranged above the base, a ring-shaped metal limiting frame is arranged on the fixed support column, and the limiting end of the ring-shaped metal limiting frame is connected with the fixed support column through a threaded connecting rod and can adjust the diameter of the ring-shaped metal limiting frame according to the diameter of the to-be-welded metal pipe; The moving station includes a first moving arm and a second moving arm. One end of the first moving arm is connected to the top slide groove of the moving station via a rolling bearing, so that one end of the first moving arm can move by rolling within the top slide groove and thus move the first moving arm. One end of the second moving arm is connected to the other end of the first moving arm via a rotating shaft. An annular metal clamp is provided at the other end of the second moving arm to grip and fix the metal pipe to be welded.

[0008] Furthermore, the judgment module includes a calculation unit and a judgment unit, wherein, The calculation unit is used to calculate the difference between the sum of the angles of the first and second weldable surfaces and the target angle. The judgment unit is used to compare the difference with the standard positive and negative angle threshold range. When the difference is within the standard positive and negative angle threshold range, the difference is judged to be qualified; when the difference exceeds the standard positive and negative angle threshold range, the difference is judged to be unqualified.

[0009] Furthermore, when the difference is deemed acceptable, the determining module determines the welding type based on the difference, including: When the difference is within the preset ideal positive and negative angle threshold range, the determining module determines the welding type as constant welding; When the difference is greater than the preset ideal positive and negative angle threshold range but less than the standard positive and negative angle threshold range, the determining module determines the welding type as variable welding.

[0010] Furthermore, when the welding type is variable welding, the control module adjusts the welding parameters for the welding robot to perform the welding action based on the weld feature parameters acquired in real time, including: The control module determines the welding torch oscillation amplitude per unit time based on the weld width per unit length, the welding torch oscillation speed based on the weld depth per unit length, and the welding torch movement speed based on the weld length; wherein, the welding torch oscillation amplitude per unit time is positively correlated with the weld width per unit length, the welding torch oscillation speed is negatively correlated with the weld depth per unit length, and the welding torch horizontal movement speed is positively correlated with the weld length.

[0011] Furthermore, the evaluation module includes a first evaluation unit, a second evaluation unit, and a third evaluation unit. The first evaluation unit is used to evaluate whether the flatness of the welding surface is qualified based on the comparison result between the gray value of the infrared image of the welding surface acquired in real time and the preset standard gray value difference, and to determine the welding surface flatness qualification rate based on the proportion of the number of image units with qualified flatness in all image units. The second evaluation unit is used to evaluate whether the continuity of the weld pattern corresponding to the three-dimensional image is qualified based on the comparison result of the curvature change value of the obtained three-dimensional image of the welded part and the preset standard curvature change value, and to determine the weld pattern continuity qualification rate based on the proportion of the three-dimensional image with qualified weld pattern continuity in the total area of ​​the three-dimensional image. The third evaluation unit is used to determine the welding missing image area based on the image area in the infrared image whose gray value is greater than the preset standard welding missing area gray value, and to determine the integrity pass rate of the welding part based on the difference between the ratio of the area of ​​the welding missing image area to the area of ​​the complete image area of ​​the welding part and 1. When the weld surface flatness pass rate is less than the preset standard flatness pass rate, the evaluation module evaluates the welding quality as unqualified for weld surface flatness. When the weld pattern continuity pass rate is less than the preset standard weld pattern continuity pass rate, the evaluation module evaluates the welding quality as weld pattern continuity failure. When the integrity pass rate of the welded part is less than the preset standard welded part integrity pass rate, the evaluation module evaluates the welding quality as unqualified in terms of the integrity of the welded part.

[0012] Furthermore, the analysis module determines a first adjustment coefficient based on the difference between the weld surface flatness pass rate and the preset standard flatness pass rate, a second adjustment coefficient based on the difference between the weld pattern continuity pass rate and the preset standard weld pattern continuity pass rate, and a third adjustment coefficient based on the difference between the weld integrity pass rate and the preset standard weld integrity pass rate.

[0013] Furthermore, the adjustment module includes a first adjustment unit and a second adjustment unit. The first adjustment unit is used to adjust the oscillation amplitude of the welding torch according to a first adjustment coefficient, adjust the oscillation speed of the welding torch according to a second adjustment coefficient, and adjust the translation speed of the welding torch according to a third adjustment coefficient.

[0014] Furthermore, the second adjustment unit is used to determine whether to continue secondary adjustment of welding parameters or adjustment of positive and negative angle adjustment coefficients based on the change in welding quality before and after the first adjustment, including: The change in welding quality is a weighted average of the changes in the weld surface flatness pass rate, the weld pattern continuity pass rate, and the weld integrity pass rate. When the weld quality after one adjustment is less than the preset standard weld quality, the second adjustment unit calculates the difference between the weld quality before and after the adjustment to determine the change in weld quality, and compares the change in weld quality with the preset standard change in weld quality: When the change in welding quality is greater than or equal to the preset standard change in welding quality, the second adjustment unit continues to make secondary adjustments to the welding parameters. When the change in welding quality is less than the preset standard change in welding quality, the second adjustment unit adjusts the positive and negative angle adjustment coefficients to adjust the preset ideal positive and negative angles.

[0015] Furthermore, it also includes a pre-determination module connected to the acquisition module, used to determine the standard positive and negative angles and allowable displacements based on the outer diameter and wall thickness of the metal pipe to be welded, including: The outer diameter and wall thickness of the metal pipe to be welded are acquired in real time. The standard positive and negative angle values ​​are determined to be the minimum of the product of the outer diameter of the pipe and the first angle adjustment coefficient and the product of the wall thickness of the pipe and the second angle adjustment coefficient. The allowable displacement value is determined to be the minimum of the product of the outer diameter of the pipe and the first displacement adjustment coefficient and the product of the wall thickness of the pipe and the second displacement adjustment coefficient.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The judgment module determines whether the difference between the sum of the angles of the first and second weldable surfaces and the target angle is acceptable based on a standard positive and negative angle threshold range, thus initially determining whether the welding angles of the first and second weldable surfaces meet the welding conditions; the determination module determines the welding type based on the comparison result of the difference with a preset ideal positive and negative angle, achieving classification of the welding of the two weldable surfaces; the control module adjusts the welding parameters of the welding robot based on the welding type and real-time acquired weld feature parameters, achieving adjustment of welding parameters for different welding types and weld conditions, improving the flexibility and accuracy of the control process; and the evaluation module combines the weld surface flatness pass rate, weld pattern continuity pass rate, and weld integrity... The pass rate assessment of welding quality enables multi-dimensional evaluation, improving the accuracy of welding quality assessment. The analysis module determines the adjustment coefficients of welding parameters based on the welding quality, and the adjustment module adjusts the welding parameters once based on these coefficients, achieving precise control of the welding process and further improving welding quality. The adjustment module determines whether to continue adjusting the welding parameters or the positive and negative angle adjustment coefficients based on the change in welding quality before and after the first adjustment, allowing for further inspection of the adjusted welding quality. For cases where the welding quality is still unqualified after the first adjustment, further analysis is conducted to determine whether to continue adjusting the unqualified welding details or adjust the positive and negative angle adjustment coefficients before welding, making the control process more targeted and effectively improving welding quality.

[0017] In particular, by setting fixed and movable stations through the positioning mechanism, the first weldable section can be fixed at the fixed station, and the second weldable section can be moved at the movable station, thus improving the working accuracy of the positioning mechanism. By setting a circular rotating disk at the fixed station and a limiting device for the metal tube on the circular rotating disk, the first weldable metal tube can be limited and fixed on the circular rotating disk, and the rotation of the circular rotating disk can drive the first weldable metal tube to rotate to the required welding angle. By setting at least two fixed support columns above the base and setting an annular metal limiting frame on the fixed support columns, the first weldable metal tube can be fixed after rotating to the required angle. The first moving mechanism of the movable station realizes the horizontal movement of the second weldable metal tube, and the first moving mechanism realizes the horizontal movement of the second weldable metal tube with angular rotation. The annular metal clamp realizes the fixation of the second weldable metal tube. The robotic arm and welding torch of the welding station are rotatably connected by a rotating shaft, so that the welding torch can rotate flexibly and determine its position during the welding process.

[0018] In particular, the judgment module compares the difference between the sum of the angles of the first and second weldable surfaces and the target angle with the standard positive and negative angle threshold range to obtain the judgment result, and preliminarily judges whether the welding angles of the first and second weldable surfaces meet the welding conditions.

[0019] In particular, by determining the welding type based on the comparison between the difference and the preset ideal positive and negative angles, the classification of welding of two cut surfaces to be welded is realized.

[0020] In particular, the control module determines the welding torch oscillation amplitude per unit time based on the weld width per unit length, achieving precise control of the welding torch oscillation amplitude; the control module determines the welding torch oscillation speed based on the weld depth per unit length, achieving precise control of the welding torch oscillation speed; the control module determines the welding torch movement speed based on the weld length, achieving precise control of the welding torch movement speed; and the control module adjusts the welding parameters for the welding robot to perform welding actions based on the welding type and real-time acquired weld characteristic parameters, enabling the adjustment of welding parameters for different welding types and weld conditions, thus improving the flexibility and accuracy of the control process.

[0021] In particular, the first evaluation unit determines the weld surface flatness pass rate based on the grayscale value of the infrared image of the weld surface acquired in real time, achieving accurate evaluation of the weld surface flatness pass rate; the second evaluation unit determines the weld pattern continuity pass rate based on the curvature change value of the three-dimensional image of the weld area, achieving accurate evaluation of the weld pattern continuity pass rate; the third evaluation unit determines the weld integrity pass rate based on the difference between the ratio of the area of ​​the missing image region in the weld area to the area of ​​the complete image region in the welded part and 1, achieving accurate evaluation of the weld integrity pass rate; by combining the weld surface flatness pass rate, weld pattern continuity pass rate, and weld integrity pass rate in the evaluation module, the welding quality is evaluated in a multi-dimensional way, improving the accuracy of the welding quality evaluation.

[0022] In particular, the analysis module determines the first adjustment coefficient based on the weld surface flatness pass rate, the second adjustment coefficient based on the weld pattern continuity pass rate, and the third adjustment coefficient based on the weld integrity pass rate, thereby enabling multi-dimensional analysis of welding quality indicators and determining different adjustment coefficients for different welding parameters, thus improving the accuracy of the analysis results.

[0023] In particular, by adjusting the oscillation amplitude of the welding torch according to the first adjustment coefficient, adjusting the oscillation speed of the welding torch according to the second adjustment coefficient, and adjusting the translation speed of the welding torch according to the third adjustment coefficient, the first adjustment unit can precisely adjust different welding parameters during the welding process, improve the accuracy of welding parameters, achieve precise control of the welding process, and further improve welding quality.

[0024] In particular, by comparing the changes in welding quality before and after the first adjustment with the preset standard welding quality change through the second adjustment unit, it is determined whether to continue to adjust the welding parameters or adjust the positive and negative angle adjustment coefficients. This enables further inspection of the adjusted welding quality. Furthermore, it allows for further analysis of cases where the welding quality is still unqualified after the first adjustment, and then determines whether to continue adjusting the unqualified welding details or adjust the positive and negative angle adjustment coefficients before welding. This makes the control process more targeted and more effectively improves the welding quality.

[0025] In particular, the pre-determination module determines the standard positive and negative angles and standard displacements based on the outer diameter and wall thickness of the metal pipe to be welded, so that different pipe diameters and wall thicknesses will have different determination results during the control process, thus achieving flexible determination of standard positive and negative angles and standard displacements. Attached Figure Description

[0026] Figure 1 This is a structural diagram of the metal pipe welding robot control system in an embodiment of the present invention; Figure 2 This is a structural diagram of the judgment module of the metal pipe welding robot control system in an embodiment of the present invention; Figure 3 This is a structural diagram of the evaluation module of the metal pipe welding robot control system in an embodiment of the present invention; Figure 4 This is a structural diagram of the adjustment module of the metal pipe welding robot control system in an embodiment of the present invention; Reference numerals in the attached diagram: 1. Acquisition module; 2. Judgment module; 3. Determination module; 4. Control module; 5. Evaluation module; 6. Analysis module; 7. Adjustment module; 8. Pre-determination module; 21. Calculation unit; 22. Judgment unit; 51. First evaluation unit; 52. Second evaluation unit; 53. Third evaluation unit; 71. First adjustment unit; 72. First adjustment unit. Detailed Implementation

[0027] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0028] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0030] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] Please see Figure 1 As shown, it is a structural diagram of the metal pipe welding robot control system in an embodiment of the present invention.

[0032] This invention provides a control system for a metal pipe welding robot, comprising: The acquisition module 1 is used to acquire the first welding section angle, the second welding section angle, the position of the metal pipe to be welded, the outer diameter of the pipe and the wall thickness of the pipe, and to acquire weld feature parameters in real time; the weld feature parameters include weld length, weld width and weld depth. Judgment module 2, connected to the acquisition module, is used to determine whether the difference between the sum of the angles of the first and second weldable surfaces and the target angle is qualified according to the standard positive and negative angle threshold range. The determination module 3, connected to the judgment module, is used to determine the welding type based on the comparison result between the difference and the preset ideal positive and negative angles; the preset ideal positive and negative angles are the product of the standard positive and negative angles and the positive and negative angle adjustment coefficients, the positive and negative angle adjustment coefficients are between 0 and 1, and the welding types include constant welding and variable welding; The control module 4 is connected to the determination module and is used to control the welding parameters of the welding robot to perform welding actions according to the welding type and the weld feature parameters acquired in real time. Evaluation module 5, connected to the control module, is used to evaluate welding quality by combining the weld surface flatness pass rate, weld pattern continuity pass rate, and weld integrity pass rate. Analysis module 6, connected to the evaluation module, is used to determine the adjustment coefficient of welding parameters based on the welding quality; The adjustment module 7 is connected to the analysis module and is used to adjust the welding parameters once according to the adjustment coefficient, and to determine whether to continue to adjust the welding parameters or adjust the positive and negative angle adjustment coefficients based on the change in welding quality before and after the first adjustment.

[0033] The judgment module determines whether the difference between the sum of the angles of the first and second weldable surfaces and the target angle is acceptable based on the standard positive and negative angle threshold range, thus initially judging whether the welding angles of the first and second weldable surfaces meet the welding conditions. The determination module determines the welding type based on the comparison between the difference and the preset ideal positive and negative angles, achieving classification of the welding of the two weldable surfaces. The control module adjusts the welding parameters of the welding robot based on the welding type and real-time acquired weld characteristic parameters, enabling adjustment of welding parameters for different welding types and weld conditions, improving the flexibility and accuracy of the control process. The evaluation module assesses the welding quality by combining the weld surface flatness pass rate, weld pattern continuity pass rate, and weld integrity pass rate. The system enables multi-dimensional assessment of welding quality, improving the accuracy of welding quality evaluation. The analysis module determines the adjustment coefficients of welding parameters based on the welding quality, and the adjustment module adjusts the welding parameters once based on these coefficients, achieving precise control of the welding process and further improving welding quality. The adjustment module determines whether to continue adjusting the welding parameters or the positive and negative angle adjustment coefficients based on the change in welding quality before and after the first adjustment, enabling further inspection of the adjusted welding quality. For cases where the welding quality is still unqualified after the first adjustment, further analysis is conducted to determine whether to continue adjusting the unqualified welding details or adjust the positive and negative angle adjustment coefficients before welding, making the control process more targeted and effectively improving welding quality.

[0034] Specifically, it also includes a positioning mechanism for positioning the metal pipe to be welded and the cut surface to be welded. The positioning mechanism includes a fixed station and a movable station. The fixed workstation includes a base, with a circular rotating disk positioned at the center of the base surface. The circular rotating disk is connected to the base via a central shaft, and a limiting device for a metal tube is provided on the circular rotating disk to limit and fix the first metal tube to be welded onto the circular rotating disk. The circular rotating disk is rotatable, with a rotation angle of 0–360°, to adjust the position of the first metal tube to be welded. At least two fixed support columns are provided above the base, and an annular metal limiting frame is provided on the fixed support columns. The limiting end of the annular metal limiting frame is connected to the fixed support column via a threaded connecting rod, and the diameter of the annular metal limiting frame can be adjusted according to the diameter of the metal tube to be welded. The moving station includes a first moving arm and a second moving arm. One end of the first moving arm is connected to the top slide groove of the moving station via a rolling bearing, so that one end of the first moving arm can move by rolling within the top slide groove and thus move the first moving arm. One end of the second moving arm is connected to the other end of the first moving arm via a rotating shaft. An annular metal clamp is provided at the other end of the second moving arm to grip and fix the metal pipe to be welded.

[0035] Specifically, it also includes a welding station, which includes at least: a welding base, a first robotic arm, a second robotic arm, and a welding torch, wherein the first robotic arm is rotatably connected to the welding base via a first rotating shaft; the second robotic arm is rotatably connected to the first robotic arm via a second rotating shaft; and the welding torch is rotatably connected to the second robotic arm via a third rotating shaft.

[0036] By setting fixed and movable stations through a positioning mechanism, the first weldable section can be fixed at the fixed station, and the second weldable section can be moved at the movable station, thus improving the working accuracy of the positioning mechanism. By setting a circular rotating disk at the fixed station and a limiting device for the metal tube on the circular rotating disk, the first weldable metal tube can be limited and fixed on the circular rotating disk, and the rotation of the circular rotating disk can drive the first weldable metal tube to be rotated to the required welding angle. By setting at least two fixed support columns above the base and setting an annular metal limiting frame on the fixed support columns, the first weldable metal tube can be fixed after rotating to the required angle. The first moving arm of the movable station enables the horizontal movement of the second weldable metal tube, and the first moving arm enables the horizontal movement of the second weldable metal tube with angular rotation. The annular metal clamp is used to fix the second weldable metal tube. The robotic arm and welding torch of the welding station are connected by a rotating shaft, which enables the welding torch to rotate flexibly and determine its position during the welding process.

[0037] In this embodiment, the working process of the positioning mechanism includes: Position the first metal pipe to be welded and the first surface to be welded: Place the first metal tube to be welded on the circular rotating disk at the center of the base surface, with the bottom center of the first metal tube to be welded coinciding with the center of the circular rotating disk. Adjust the metal tube limiting device on the circular rotating disk to secure the first metal tube to be welded on the circular rotating disk. The vision inspection module checks whether the placement of the first metal pipe to be welded is up to standard, including: First testing condition: One end of the centerline of the first metal tube to be welded falls on the center of the circular rotating disk, and the centerline of the first metal tube to be welded is perpendicular to the surface of the circular rotating disk. Second testing conditions: The first welding surface of the first metal pipe to be welded faces the moving station, and the projection of the first center line of the first welding surface is perpendicular to the center line of the top slide groove, and the projection of the second center line of the first welding surface is parallel to the center line of the top slide groove. When the test result is unqualified, adjust the position of the first metal pipe to be welded; After the test result is qualified, adjust the limiting end of the annular metal limiting frame to fasten the first metal pipe to be welded on the fixed support column.

[0038] Positioning the second metal pipe to be welded and the second surface to be welded: At the moving station: the ring-shaped metal hand grasps the second metal pipe to be welded and aligns the second welding surface of the second metal pipe with the fixed station. The vision inspection module checks whether the placement of the second metal pipe to be welded is up to standard, including: First testing condition: The second welding surface of the second metal pipe to be welded faces the fixed station, and the projection of the first center line of the second welding surface is perpendicular to the center line of the top slide groove and the projection of the second center line of the second welding surface is parallel to the center line of the top slide groove. Second detection condition: The distance between the first surface to be welded and the second surface to be welded is within a preset threshold range.

[0039] If the test result is unqualified, adjust the position of the second metal pipe to be welded; After the test result is qualified, the first moving arm is moved to attach the second surface to be welded of the second metal tube to be welded to the first surface to be welded. When the pressure reaches the preset pressure value, the movement stops.

[0040] Please see Figure 2 As shown, it is a structural diagram of the judgment module of the metal pipe welding robot control system in an embodiment of the present invention.

[0041] Specifically, the judgment module includes a calculation unit 21 and a judgment unit 22, wherein, The calculation unit is used to calculate the difference between the sum of the angles of the first and second weldable surfaces and the target angle. The judgment unit is used to compare the difference with the standard positive and negative angle threshold range. When the difference is within the standard positive and negative angle threshold range, the difference is judged to be qualified; when the difference exceeds the standard positive and negative angle threshold range, the difference is judged to be unqualified.

[0042] Specifically, in this embodiment, the target angle of the two metal tubes to be welded is 90°. In an ideal state, the angle between the first weldable surface and the horizontal direction is 45°, and the angle between the second weldable surface and the vertical direction is 45°. When determining the difference between the sum of the angles of the first and second weldable surfaces and the target angle, if the angle difference is within the range of [-1.5°, 1.5°], the angle difference is considered to be within the allowable range and therefore acceptable. When the angle difference exceeds the range of [-1.5°, 1.5°], it is determined that the angle difference is not within the allowable range and is therefore deemed unqualified.

[0043] The judgment module compares the difference between the sum of the angles of the first and second weldable surfaces and the target angle with the standard positive and negative angle threshold range to obtain the judgment result, and preliminarily judges whether the welding angles of the first and second weldable surfaces meet the welding conditions.

[0044] Specifically, when the difference is deemed acceptable, the determining module determines the welding type based on the difference, including: When the difference is within the preset ideal positive and negative angle threshold range, the determining module determines the welding type as constant welding; in this embodiment, the preset ideal positive and negative angle threshold range is [-0.6°, 0.6°], and the positive and negative angle adjustment coefficient is set to 0.4; When the difference is greater than the preset ideal positive and negative angle threshold range [-0.6°, 0.6°] and less than the standard positive and negative angle threshold range [-1.5°, 1.5°], the determining module determines the welding type as variable welding.

[0045] The module determines the welding type based on the comparison between the difference and the preset ideal positive and negative angles, thus classifying the welding of two cut surfaces to be welded.

[0046] Specifically, the constant welding means that the contact distance between the first weldable surface and the first weldable surface is a constant distance; in this embodiment, the constant distance is set to 2mm. Specifically, the variable welding refers to the varying distance between the first weldable surface and the first weldable surface; in this embodiment, the varying distance is adjusted to be between 1.8mm and 2.2mm.

[0047] Specifically, when the welding type is variable welding, the control module adjusts the welding parameters for the welding robot to perform the welding action based on the weld feature parameters acquired in real time, including: The control module determines the welding torch oscillation amplitude per unit time based on the weld width per unit length, the welding torch oscillation speed based on the weld depth per unit length, and the welding torch movement speed based on the weld length; wherein, the welding torch oscillation amplitude per unit time is positively correlated with the weld width per unit length, the welding torch oscillation speed is negatively correlated with the weld depth per unit length, and the welding torch horizontal movement speed is positively correlated with the weld length.

[0048] The control module determines the welding torch oscillation amplitude per unit time based on the weld width per unit length, achieving precise control of the welding torch oscillation amplitude; the control module determines the welding torch oscillation speed based on the weld depth per unit length, achieving precise control of the welding torch oscillation speed; the control module determines the welding torch movement speed based on the weld length, achieving precise control of the welding torch movement speed; the control module adjusts the welding parameters for the welding robot's welding actions based on the welding type and real-time acquired weld characteristic parameters, enabling adjustment of welding parameters for different welding types and weld conditions, improving the flexibility and accuracy of the control process.

[0049] Please see Figure 3 As shown, it is a structural diagram of the evaluation module of the metal pipe welding robot control system in an embodiment of the present invention.

[0050] Specifically, the evaluation module includes a first evaluation unit 51, a second evaluation unit 52 and a third evaluation unit 53. The first evaluation unit is used to evaluate whether the flatness of the welding surface is qualified based on the comparison result between the gray value of the infrared image of the welding surface acquired in real time and the preset standard gray value difference, and to determine the flatness qualification rate of the welding surface based on the proportion of the number of image units with qualified flatness in all image units. In this embodiment, the first evaluation unit acquires infrared images of the welding surface in real time through the acquisition module; divides the infrared image into several image units and compares the gray values ​​of adjacent image units to obtain gray value differences; determines the flatness of the welding surface based on the gray value differences; when the gray value differences are within a preset standard gray value difference threshold range, the flatness of the welding surface corresponding to the adjacent image unit is determined to be qualified; when the gray value differences exceed the preset standard gray value difference threshold range, the flatness of the welding surface corresponding to the adjacent image unit is determined to be unqualified; the proportion of adjacent image units with qualified welding surface flatness corresponding to the adjacent image units in all image units is determined as the welding surface flatness qualification rate.

[0051] Specifically, the second evaluation unit is used to evaluate whether the continuity of the weld pattern corresponding to the three-dimensional image is qualified based on the comparison result of the curvature change value of the obtained three-dimensional image of the welded area and the preset standard curvature change value, and to determine the weld pattern continuity qualification rate based on the proportion of the three-dimensional image with qualified weld pattern continuity in the total area of ​​the three-dimensional image. In this embodiment, the second evaluation unit divides the acquired three-dimensional image of the welded area into a mesh and calculates the curvature change value of adjacent three-dimensional image meshes of the welded area; it determines the continuity of the weld pattern based on the curvature change value; when the curvature change value is within a preset standard curvature change value threshold range, it determines that the continuity of the weld pattern corresponding to the adjacent three-dimensional image mesh is qualified; when the curvature change value exceeds the preset standard curvature change value threshold range, it determines that the continuity of the weld pattern corresponding to the adjacent three-dimensional image mesh is unqualified; the proportion of adjacent three-dimensional image meshes with qualified weld pattern continuity in all three-dimensional image meshes is determined as the weld pattern continuity qualification rate.

[0052] Specifically, the third evaluation unit is used to determine the welding defect image area based on the image area in the infrared image whose gray value is greater than the preset standard welding defect area gray value, and to determine the integrity pass rate of the welding part based on the difference between the ratio of the area of ​​the welding defect image area to the area of ​​the complete image area of ​​the welding part and 1.

[0053] When the weld surface flatness pass rate is less than the preset standard flatness pass rate, the evaluation module evaluates the welding quality as unqualified for weld surface flatness. When the weld pattern continuity pass rate is less than the preset standard weld pattern continuity pass rate, the evaluation module evaluates the welding quality as weld pattern continuity failure. When the integrity pass rate of the welded part is less than the preset standard welded part integrity pass rate, the evaluation module evaluates the welding quality as unqualified in terms of the integrity of the welded part.

[0054] The first evaluation unit determines the weld surface flatness pass rate based on the grayscale value of the infrared image of the weld surface acquired in real time, achieving accurate evaluation of the weld surface flatness pass rate. The second evaluation unit determines the weld pattern continuity pass rate based on the curvature change value of the three-dimensional image of the weld area, achieving accurate evaluation of the weld pattern continuity pass rate. The third evaluation unit determines the weld integrity pass rate based on the difference between the ratio of the area of ​​the missing image region in the weld area to the area of ​​the complete image region in the weld area and 1, achieving accurate evaluation of the weld integrity pass rate. By combining the weld surface flatness pass rate, weld pattern continuity pass rate, and weld integrity pass rate, the evaluation module assesses the weld quality in a multi-dimensional way, improving the accuracy of the weld quality assessment.

[0055] Specifically, the analysis module determines a first adjustment coefficient based on the difference between the weld surface flatness pass rate and the preset standard flatness pass rate, a second adjustment coefficient based on the difference between the weld pattern continuity pass rate and the preset standard weld pattern continuity pass rate, and a third adjustment coefficient based on the difference between the weld part integrity pass rate and the preset standard weld part integrity pass rate.

[0056] The analysis module determines the first adjustment coefficient based on the weld surface flatness pass rate, the second adjustment coefficient based on the weld pattern continuity pass rate, and the third adjustment coefficient based on the weld integrity pass rate. This enables multi-dimensional analysis of welding quality indicators and allows for the determination of different adjustment coefficients for different welding parameters, thereby improving the accuracy of the analysis results.

[0057] Please see Figure 4 As shown, it is a structural diagram of the adjustment module of the metal pipe welding robot control system in an embodiment of the present invention.

[0058] Specifically, the adjustment module includes a first adjustment unit 71 and a second adjustment unit 72. The first adjustment unit is used to adjust the oscillation amplitude of the welding torch according to a first adjustment coefficient, adjust the oscillation speed of the welding torch according to a second adjustment coefficient, and adjust the translation speed of the welding torch according to a third adjustment coefficient.

[0059] By adjusting the oscillation amplitude of the welding torch according to the first adjustment coefficient, the oscillation speed of the welding torch according to the second adjustment coefficient, and the translation speed of the welding torch according to the third adjustment coefficient, the precise adjustment of different welding parameters during the welding process is achieved, thereby improving the accuracy of the welding parameters, realizing precise control of the welding process, and further improving the welding quality.

[0060] Specifically, the second adjustment unit is used to determine whether to continue secondary adjustment of welding parameters or adjustment of positive and negative angle adjustment coefficients based on the change in welding quality before and after the first adjustment, including: The change in welding quality is a weighted average of the changes in the weld surface flatness pass rate, the weld pattern continuity pass rate, and the weld integrity pass rate. When the welding quality after one adjustment is greater than or equal to the preset standard welding quality, the second adjustment unit will not perform a second adjustment; When the weld quality after one adjustment is less than the preset standard weld quality, the second adjustment unit calculates the difference between the weld quality before and after the adjustment to determine the change in weld quality, and compares the change in weld quality with the preset standard change in weld quality: When the change in welding quality is greater than or equal to the preset standard change in welding quality, the second adjustment unit continues to make secondary adjustments to the welding parameters. When the change in welding quality is less than the preset standard change in welding quality, the second adjustment unit adjusts the positive and negative angle adjustment coefficients to adjust the preset ideal positive and negative angles.

[0061] The second adjustment unit compares the changes in welding quality before and after the first adjustment with the preset standard welding quality change to determine whether to continue adjusting the welding parameters or to adjust the positive and negative angle adjustment coefficients. This allows for further inspection of the adjusted welding quality. Furthermore, it analyzes cases where the welding quality remains unqualified after the first adjustment, determining whether to continue adjusting the unqualified welding details or to adjust the positive and negative angle adjustment coefficients before welding. This makes the control process more targeted and effectively improves welding quality.

[0062] Specifically, it also includes a pre-determination module 8, connected to the acquisition module, used to determine the standard positive and negative angles and allowable displacements based on the outer diameter and wall thickness of the metal pipe to be welded, including: The outer diameter and wall thickness of the metal pipe to be welded are acquired in real time. The standard positive and negative angle values ​​are determined to be the minimum of the product of the outer diameter of the pipe and the first angle adjustment coefficient and the product of the wall thickness of the pipe and the second angle adjustment coefficient. The allowable displacement value is determined to be the minimum of the product of the outer diameter of the pipe and the first displacement adjustment coefficient and the product of the wall thickness of the pipe and the second displacement adjustment coefficient.

[0063] In this embodiment, the outer diameter of the metal pipe to be welded is denoted as D, and the wall thickness is denoted as H. The angle is determined as Min{D×α1,H×α2}, where α1 is the first angle adjustment coefficient and α2 is the second angle adjustment coefficient. The displacement is determined as Min{D×β1,H×β2}, where β1 is the first displacement adjustment coefficient and β2 is the second displacement adjustment coefficient.

[0064] The pre-determination module determines the standard positive and negative angles and standard displacements based on the outer diameter and wall thickness of the metal pipe to be welded, so that different pipe diameters and wall thicknesses will have different determination results during the control process, thus achieving flexible determination of standard positive and negative angles and standard displacements.

[0065] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A metal pipe welding robot control system characterized by comprising: The method comprises the following steps: An acquisition module is configured to acquire a first to-be-welded section angle, a second to-be-welded section angle, a position of a to-be-welded metal pipe, an outer diameter of a pipe, a wall thickness of the pipe, and a real-time welding seam characteristic parameter; the welding seam characteristic parameter comprises a welding seam length, a welding seam width, and a welding seam depth; A judgment module is connected to the acquisition module and configured to judge whether a difference between a sum of the first to-be-welded section angle and the second to-be-welded section angle and a target angle is qualified according to a standard positive and negative angle threshold range; A determination module is connected to the judgment module and configured to determine a welding type according to a comparison result of the difference and a preset ideal positive and negative angle; the preset ideal positive and negative angle is a product of the standard positive and negative angle and a positive and negative angle adjustment coefficient, the positive and negative angle adjustment coefficient has a value between 0 and 1, and the welding type comprises constant welding and variable welding; A control module is connected to the determination module and configured to control a welding parameter of a welding robot performing a welding action according to the welding type and the real-time welding seam characteristic parameter; An evaluation module is connected to the control module and configured to evaluate a welding quality in combination with a welding surface flatness qualification rate, a welding line continuity qualification rate, and a welding part completeness qualification rate; An analysis module is connected to the evaluation module and configured to determine an adjustment coefficient of the welding parameter according to the welding quality; An adjustment module is connected to the analysis module and configured to adjust the welding parameter once according to the adjustment coefficient, and determine whether to continue to adjust the welding parameter twice or adjust the positive and negative angle adjustment coefficient according to a welding quality change amount before and after the first adjustment.

2. The metal tube welding robot control system according to claim 1, characterized by, The method further comprises a positioning mechanism configured to position a to-be-welded metal pipe and a to-be-welded section, the positioning mechanism comprises a fixed station and a mobile station, wherein the fixed station comprises a base, a circular rotating disc is arranged at a center position on a surface of the base, the circular rotating disc is connected to the base through a center shaft, a metal pipe limiting device is arranged on the circular rotating disc, the first to-be-welded metal pipe is limited and fixed on the circular rotating disc through the metal pipe limiting device, the circular rotating disc is rotatable, a rotating angle is 0-360°, and the position of the first to-be-welded metal pipe is adjusted; at least two fixed support columns are arranged above the base, an annular metal limiting frame is arranged on the fixed support column, and a limiting end of the annular metal limiting frame is connected to the fixed support column through a threaded connecting rod and can adjust a diameter of the annular metal limiting frame according to a diameter of the to-be-welded metal pipe; the mobile station comprises a first mobile arm and a second mobile arm, one end of the first mobile arm is connected to a top sliding groove of the mobile station through a rolling bearing, one end of the first mobile arm is moved in the top sliding groove through rolling and drives the first mobile arm to move, one end of the second mobile arm is connected to the other end of the first mobile arm through a rotating shaft, and an annular metal clamp is arranged at the other end of the second mobile arm to grab and fix the to-be-welded metal pipe.

3. The metal tube welding robot control system according to claim 2, characterized by, The judgment module comprises a calculation unit and a judgment unit, wherein The computing unit is configured to calculate a difference between a sum of an angle of the first to-be-welded section and an angle of the second to-be-welded section and the target angle; The judging unit is configured to compare the difference with a standard positive and negative angle threshold range, and determine that the difference is qualified when the difference is within the standard positive and negative angle threshold range, and determine that the difference is unqualified when the difference is out of the standard positive and negative angle threshold range.

4. The metal tube welding robot control system according to claim 3, characterized by, When it is determined that the difference is qualified, the determining module determines the welding type according to the difference, including: When the difference is within a preset ideal positive and negative angle threshold range, the determining module determines that the welding type is constant welding. When the difference is greater than the preset ideal positive and negative angle threshold range and less than the standard positive and negative angle threshold range, the determining module determines that the welding type is variable welding.

5. The metal tube welding robot control system according to claim 4, wherein, When the welding type is variable welding, the control module controls the welding robot to perform welding actions according to real-time welding feature parameters, including: The control module determines a welding gun swing amplitude in a unit time according to a welding seam width in a unit length, a welding gun swing speed according to a welding seam depth in a unit length, and a welding gun moving speed according to the welding seam length; wherein the welding gun swing amplitude in a unit time is positively correlated with the welding seam width in a unit length, the welding gun swing speed is negatively correlated with the welding seam depth in a unit length, and the welding gun horizontal moving speed is positively correlated with the welding seam length.

6. The metal tube welding robot control system according to claim 5, wherein, The evaluation module includes a first evaluation unit, a second evaluation unit, and a third evaluation unit, wherein the first evaluation unit is configured to evaluate whether the welding surface flatness is qualified according to a comparison result of a gray value of a real-time infrared image of a welding surface and a preset standard gray value difference, and determine a welding surface flatness qualification rate according to a proportion of image units with qualified flatness in all image units; The second evaluation unit is configured to evaluate whether the welding texture continuity is qualified according to a comparison result of a curvature change value of a three-dimensional image of a welding local part and a preset standard curvature change value, and determine a welding texture continuity qualification rate according to a proportion of three-dimensional images with qualified welding texture continuity in a total three-dimensional image area; The third evaluation unit is configured to determine a welding missing image area according to image areas with a gray value greater than a preset standard welding missing area gray value on the infrared image, and determine a welding site completeness qualification rate according to a difference between a proportion of the welding missing image area in a complete image area of the welding site and 1; When the welding surface flatness qualification rate is less than a preset standard flatness qualification rate, the evaluation module evaluates that the welding quality is unqualified in terms of welding surface flatness. When the welding texture continuity qualification rate is less than a preset standard welding texture continuity qualification rate, the evaluation module evaluates that the welding quality is unqualified in terms of welding texture continuity. When the welding site completeness qualification rate is less than a preset standard welding site completeness qualification rate, the evaluation module evaluates that the welding quality is unqualified in terms of welding site completeness.

7. The metal tube welding robot control system according to claim 6, wherein, The analysis module determines a first adjustment coefficient according to a difference between the welding surface flatness pass rate and a preset standard flatness pass rate, a second adjustment coefficient according to a difference between the welding line continuity pass rate and a preset standard welding line continuity pass rate, and a third adjustment coefficient according to a difference between the welding site integrity pass rate and a preset standard welding site integrity pass rate.

8. The metal tube welding robot control system according to claim 7, wherein, The adjustment module includes a first adjustment unit and a second adjustment unit. The first adjustment unit adjusts the swing amplitude of the welding torch according to the first adjustment coefficient, adjusts the swing speed of the welding torch according to the second adjustment coefficient, and adjusts the translation speed of the welding torch according to the third adjustment coefficient.

9. The metal tube welding robot control system according to claim 8, wherein, The second adjustment unit determines whether to continue the secondary adjustment of the welding parameters or the adjustment of the positive and negative angle adjustment coefficients according to the welding quality change amount before the first adjustment and after the first adjustment, including: The welding quality change amount is a weighted average of the welding surface flatness pass rate change amount, the welding line continuity pass rate change amount, and the welding site integrity pass rate change amount. When the welding quality after the first adjustment is less than the preset standard welding quality, the second adjustment unit calculates the difference between the welding quality before the first adjustment and the welding quality after the first adjustment to determine the welding quality change amount, and compares the welding quality change amount with a preset standard welding quality change amount: When the welding quality change amount is greater than or equal to the preset standard welding quality change amount, the second adjustment unit continues the secondary adjustment of the welding parameters. When the welding quality change amount is less than the preset standard welding quality change amount, the second adjustment unit adjusts the positive and negative angle adjustment coefficients to adjust the preset ideal positive and negative angle.

10. The metal tube welding robot control system according to claim 9, wherein, The pre-determination module is connected with the acquisition module and determines the standard positive and negative angle and the allowable displacement according to the pipe outer diameter and the pipe wall thickness of the metal pipe to be welded, including: The pipe outer diameter and the pipe wall thickness of the metal pipe to be welded are acquired in real time, the standard positive and negative angle is determined to be the minimum value of the product of the pipe outer diameter and a first angle adjustment coefficient and the product of the pipe wall thickness and a second angle adjustment coefficient, and the allowable displacement is determined to be the minimum value of the product of the pipe outer diameter and a first displacement adjustment coefficient and the product of the pipe wall thickness and a second displacement adjustment coefficient.

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