CN114399461B - Intelligent toe mechanical polishing fatigue life-prolonging method - Google Patents
Intelligent toe mechanical polishing fatigue life-prolonging method Download PDFInfo
- Publication number
- CN114399461B CN114399461B CN202111459823.7A CN202111459823A CN114399461B CN 114399461 B CN114399461 B CN 114399461B CN 202111459823 A CN202111459823 A CN 202111459823A CN 114399461 B CN114399461 B CN 114399461B
- Authority
- CN
- China
- Prior art keywords
- point
- polishing
- frame
- image
- axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
- G06T7/0004—Industrial image inspection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J11/00—Manipulators not otherwise provided for
- B25J11/005—Manipulators for mechanical processing tasks
- B25J11/0065—Polishing or grinding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1656—Programme controls characterised by programming, planning systems for manipulators
- B25J9/1664—Programme controls characterised by programming, planning systems for manipulators characterised by motion, path, trajectory planning
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1679—Programme controls characterised by the tasks executed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1694—Programme controls characterised by use of sensors other than normal servo-feedback from position, speed or acceleration sensors, perception control, multi-sensor controlled systems, sensor fusion
- B25J9/1697—Vision controlled systems
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/10—Segmentation; Edge detection
- G06T7/13—Edge detection
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/70—Determining position or orientation of objects or cameras
- G06T7/73—Determining position or orientation of objects or cameras using feature-based methods
- G06T7/74—Determining position or orientation of objects or cameras using feature-based methods involving reference images or patches
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/30—Subject of image; Context of image processing
- G06T2207/30108—Industrial image inspection
- G06T2207/30152—Solder
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/30—Computing systems specially adapted for manufacturing
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Robotics (AREA)
- Mechanical Engineering (AREA)
- General Physics & Mathematics (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Quality & Reliability (AREA)
- Computer Graphics (AREA)
- Geometry (AREA)
- Software Systems (AREA)
- Laser Beam Processing (AREA)
- Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
Abstract
The invention provides an intelligent toe mechanical polishing fatigue life-prolonging method, which comprises the following steps: (1) weld scanning; (2) image processing; (3) extracting characteristic points of each frame of image; (4) determining polishing start and end points of each frame of image; (5) grinding track calculation; (6) determining the pose of the grinding head of each frame of image; and (7) polishing the welding line. The intelligent toe mechanical polishing fatigue life-prolonging method has the advantages of being applicable to complex and narrow spaces, capable of automatically identifying welding seams and fitting and calculating polishing tracks, capable of adjusting the space pose of a grinding head on line, good in polishing effect and high in efficiency.
Description
Technical Field
The invention relates to a fatigue life-prolonging technology for structural members, in particular to an intelligent toe mechanical polishing fatigue life-prolonging method.
Background
Fatigue failure is the most important failure mode of a welded structure, and the fatigue performance of the welded structure can be reduced under the combined actions of stress concentration, welding defects and residual tensile stress attached to a welded joint. The main methods for improving the fatigue performance of the structural member at present include a welding seam and welding toe mechanical polishing technology, a hammering technology, a TIG (tungsten inert gas) melting and repairing technology, an ultrasonic impact technology and the like, wherein the welding seam and welding toe mechanical polishing technology is favored by welding workers because of convenient implementation, remarkable improvement of fatigue strength, low cost and other performances, is the most scheme used during actual fatigue modification, but most of the factory technologies are relatively backward at present, a manual welding seam and welding toe mechanical polishing mode is mainly adopted, the efficiency is low, the manual polishing process cannot be implemented strictly according to parameters specified by standards, the final polishing precision and effect are relatively high in dependence on quality of workers, and metal scraps, noise and smoke generated by polishing also cause hidden danger to human health.
Based on the adverse factors of the traditional manual mechanical polishing weld and weld toe modes, welding students start to gradually turn to the research of the automatic weld polishing mode, and at present, two main modes exist: (1) a polishing mode programmed based on a teaching track; the method sets parameters such as polishing depth, polishing track, grinding head running speed, grinding head rotating speed and the like in advance, can be suitable for flat butt welding seams, cylindrical ring/longitudinal butt welding seam polishing occasions, and is difficult to be suitable for occasions requiring space real-time change of fillet welding seam polishing and grinding head pose. (2) A weld seam surplus height polishing mode based on structured light visual track tracking; the method utilizes structured light vision pre-scanning or real-time scanning to obtain characteristic points of the welding seam, and further obtains polishing track and polishing depth of a welding seam grinding head, but the method also has the following technical characteristics: (1) the method is more used for polishing butt welding seams, the occasion is wide in space and simpler to operate, but for occasions with severely limited angle joint welding seams or space pose, such as a hydraulic support top beam structural member, the polishing mode of the structural light visual track tracking can fail, and the structural form of a polishing tool and a related algorithm of a structural light visual acquisition polishing process must be improved; (2) the method is mainly used for the situation of grinding the weld seam surplus height, the pose of a grinding tool is not required to be adjusted on line in the grinding process, the follow-up grinding can be completed only by setting the initial position, and in the situation of the intelligent grinding fatigue life-prolonging method for the weld toe, the standard has the stipulated requirement on the included angle between the grinding tool and the weld seam, and the pose of the grinding tool can be adjusted on line according to different positions of the weld seam, so that the method cannot be implemented.
In summary, in the field of fatigue life extension of fillet weld toe polishing, there is no related technology for intelligent polishing, and the study of those skilled in the art is still in a blank state, and since fatigue life extension polishing of a weld is specified in the standard for various parameters, the characteristics that must be satisfied in the process of intelligent polishing are: (1) Can operate in a complex and narrow space, and has the function of operation safety assessment; (2) The grinding track and the grinding depth can be automatically set, and the real-time adjustment of the space pose of the grinding head can be realized.
In order to solve the above problems, an ideal technical solution is always sought.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the intelligent toe mechanical polishing fatigue life-prolonging method which is applicable to complex and narrow spaces, can automatically identify welding seams and fit and calculate polishing tracks, can adjust the space pose of a grinding head on line, and has good polishing effect and high efficiency.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: an intelligent toe mechanical polishing fatigue life-prolonging method comprises the following steps: (1) weld scanning: scanning a weld to be polished frame by adopting a laser projection line, wherein a laser light plane is parallel to a weld cross section during scanning, and a laser central line is positioned on an equally divided plane of a plane included angle of a weld base material; (2) image processing: sequentially carrying out image preprocessing and central line extraction on the weld joint images scanned frame by frame to respectively obtain geometric profile shapes of the weld joint represented by the central line; (3) extracting characteristic points of each frame of image: respectively setting two end points of the geometric outline of the welding seam as a point A and a point B, wherein an initial three-dimensional coordinate system is established by taking a straight line of the point A on the geometric outline of the welding seam as an X axis and a direction perpendicular to a plane of the geometric outline of the welding seam as an ordinate, and setting a point with the lowest pixel point vertical coordinate and more than 20 pixels lower than the point A vertical coordinate as a point S; when the S point exists, the frame image has an undercut defect, a first endpoint is an H point from the A point, a second endpoint is a D point, and a first endpoint is a C point from the B point; when the S point does not exist, the frame image does not have undercut defect, and the first endpoint is the C point, and the second endpoint is the D point from the B point; (4) determining polishing start and end points of each frame of image: when the frame image has an undercut defect, taking a central point of a connecting line of a D point and an H point as a polishing initial action point J, and when the frame image does not have the undercut defect, taking the D point as the polishing initial action point J and taking the J point as an original point of an initial three-dimensional coordinate system; on the geometric outline of the welding seam, finding an E point from the D point to the B point, enabling the distance of D, E to be 1/2 of the size of a welding leg, and taking the E point as a polishing minimum width point; setting the thickness of a welding seam parent metal as d, setting the included angle between the axis of the grinding head and ZY and the included angle between the axis of the grinding head and the XY plane as gamma and setting the included angle between the axis of the grinding head and the Y axis as beta, and searching the N point of the deepest grinding point on the axis of the grinding head to ensure that NJ is approximately equal to fd/cos gamma, wherein the N point is the grinding end point, and f, gamma, beta and E points are all determined by grinding standards; and (5) grinding track calculation: converting the image coordinates of N points in each frame of image into three-dimensional coordinates under the base coordinates of the polishing robot, and performing quasi-uniform three-time B spline curve fitting on the coordinates of N points in each frame of image to obtain a polishing track curve L; (6) determining the pose of the grinding head of each frame of image: obtaining an X axis through a JA linear equation, obtaining a Y axis through a J point tangent linear equation obtained through grinding a track curve L, determining a Z axis through the X axis and the Y axis, so as to obtain a final three-dimensional coordinate system, wherein the included angle between the grinding head axis and ZY and XY planes is gamma, the included angle between the grinding head axis and the Y axis is beta, and the end point of the grinding head coincides with the J point, so that the pose of the grinding head is obtained; and (7) polishing a welding line: and (3) selecting a grinding head with the radius not smaller than the EJ distance, and controlling the grinding head to grind the weld seam according to the pose in the step (6) along the grinding track curve L obtained in the step (5).
Based on the above, the image preprocessing in the step (3) includes video frame capturing, active area positioning and extraction, ostu filtering, and morphological trimming.
Based on the above, it further includes the step of obtaining the stress concentration area through actual finite element simulation, fatigue experiment or stress analysis, and determining the weld joint of the fatigue area.
Based on the above, the method further comprises a safety prediction step, wherein the included angle between the BC straight line and the AD straight line and the distance between the BC straight line and the line segment DC are calculated, and when the included angle is smaller than a threshold angle or the distance is smaller than the threshold value, the welding seam is polished to have dangerousness, so that early warning is carried out.
Based on the above, in the step (5), a mode of combining structured light visual calibration and hand-eye calibration is adopted when the image coordinates are converted into three-dimensional coordinates under the base coordinates of the polishing robot.
Based on the above, the gamma and the beta are both between 30-45 degrees.
Compared with the prior art, the method has outstanding substantive characteristics and remarkable progress, in particular, the method utilizes the laser projection line to collect weld images frame by frame, carries out image processing on each frame of image to obtain the geometric profile of the weld, extracts characteristic points, establishes an initial three-dimensional coordinate system, judges whether the frame of image has undercut defects according to preset rules, respectively determines polishing starting points, end points and points with minimum polishing width according to related polishing standards, and can respectively determine polishing starting points, end points and points with minimum polishing width according to different conditions, wherein the polishing end points can also be called actual action points, then converts pixel coordinates of each frame of actual action points into three-dimensional coordinates under a polishing robot base, fits each frame of actual action point coordinates to obtain a polishing track curve, and then establishes a final three-dimensional coordinate system by taking tangent lines of each point on the polishing track curve as a Y axis of the point, and further calculates to obtain the pose of each frame of image according to preset rules, so that the actual polishing track is smoothly transited in the polishing process, and each frame of image adopts the same polishing standard, thereby avoiding polishing transition at a certain position or insufficient polishing position, eliminating the influence of a person due to the fact that the polishing operation is stable, and the fatigue performance of a polishing machine is greatly improved.
Further, through the safety prediction step, whether the welding line can be polished or not can be automatically judged, and early warning is timely provided when danger exists.
Drawings
FIG. 1 is a schematic diagram of a polishing apparatus used in the method for intelligently polishing fatigue and prolonging life of a weld toe machine of the present invention.
FIG. 2 is a photograph of the geometry of a butt weld after image preprocessing in the present invention.
FIG. 3 is a photograph of the geometric outline of a corner joint weld after image preprocessing in the present invention.
FIG. 4 is a graph of the geometry of the butt weld after centerline extraction in the present invention.
FIG. 5 is a graph of the geometry of the fillet weld after centerline extraction in accordance with the present invention.
FIG. 6 is a mathematical model of the parameters of the sanding process described in the present invention as an example of a fillet weld.
In the figure: 1. polishing the six-axis robot; 2. a high-speed electric drive grinding wheel; 3. grinding head; 4. an industrial personal computer; 5. welding seam structural member; 6. a robot controller; 7. CCD industrial camera; 8. a line laser generator; 9. and (5) laser projection lines.
Detailed Description
The technical scheme of the invention is further described in detail through the following specific embodiments.
As shown in fig. 1-6, an intelligent toe mechanical polishing fatigue life-prolonging method comprises the following steps:
(1) Determining a weld joint to be polished: and obtaining a stress concentration area through actual finite element simulation, fatigue experiments or stress analysis, and determining a weld joint of the fatigue area.
(2) And (3) welding line scanning: the laser projection line is adopted to scan the weld joint to be polished frame by frame, when the laser projection line scans, the laser light plane is parallel to the section of the weld joint, and the laser center line is positioned on an bisection plane of the plane included angle of the weld joint parent metal, for example, for a butt weld joint, the laser center line is perpendicular to the plane of the weld joint parent metal, and for a 90-degree fillet weld, the laser center line forms an included angle of 45 degrees with the plane of the weld joint parent metal.
(3) Image processing: the frame-by-frame scanned weld images are sequentially transmitted to the industrial personal computer 4, and the weld images are subjected to image preprocessing and central line extraction, wherein the image preprocessing comprises video frame taking, effective area positioning and extraction, ostu filtering and morphological trimming, and the weld geometric outline morphology represented by the central line is obtained respectively.
(4) Extracting characteristic points of each frame of image: respectively setting two end points of the geometric outline of the welding seam as a point A and a point B, wherein an initial three-dimensional coordinate system is established by taking a straight line of the point A on the geometric outline of the welding seam as an X axis and a direction perpendicular to a plane of the geometric outline of the welding seam as an ordinate, and setting a point with the lowest pixel point vertical coordinate and more than 20 pixels lower than the point A vertical coordinate as a point S;
when the S point exists, the frame image has an undercut defect, a first endpoint is an H point from the A point, a second endpoint is a D point, and a first endpoint is a C point from the B point; when the S point does not exist, the frame image does not have undercut defect, and the first endpoint is the C point, and the second endpoint is the D point from the B point;
through this step, when there is an undercut defect in the weld, a total of A, B, C, D, S, H six feature points are obtained, and when there is no undercut defect in the weld, a total of A, B, C, D four feature points are obtained.
(5) Safety prediction: obtaining an included angle between the BC straight line and the AD straight line and a distance between the BC straight line and the line segment DC, and carrying out early warning when the included angle is smaller than a threshold angle or the distance is smaller than a threshold value, wherein the welding line is polished to have dangerousness; when there is no risk of sanding, the process can proceed to the next step.
(6) Determining polishing start and end points of each frame of image: when the frame image has an undercut defect, taking a central point of a connecting line of a D point and an H point as a polishing initial action point J, and when the frame image does not have the undercut defect, taking the D point as the polishing initial action point J and taking the J point as an original point of an initial three-dimensional coordinate system;
on the geometric outline of the welding seam, finding an E point from the D point to the B point, enabling the distance of D, E to be 1/2 of the size of a welding leg, and taking the E point as a polishing minimum width point;
setting the thickness of a welding seam parent metal as d, the included angle between the axis of the grinding head 3 and ZY and the included angle between the axis of the grinding head 3 and the Y axis as beta, and searching a grinding deepest point N point on the axis of the grinding head 3, wherein NJ is approximately equal to fd/cos gamma, and the N point is a grinding end point and can be also called an actual action point;
wherein, the f, gamma, beta and E points are all determined by polishing standards, and the gamma and the beta take values between 30 degrees and 45 degrees.
(7) And (5) grinding track calculation: converting the image coordinates of N points in each frame of image into three-dimensional coordinates under the base coordinates of the polishing robot, and performing quasi-uniform three-time B spline curve fitting on the coordinates of N points in each frame of image to obtain a polishing track curve L;
the solving of the coordinate transformation formula comprises the following steps:
(1) the calibration purpose is as follows:
pixel coordinates (u) of a point q in the weld region on a picture taken by the CCD industrial camera 7 q ，v q ) Is converted into the actual coordinates (x) q ，y q ，z q ) The origin of the camera coordinate system is the center of the light mirror of the CCD industrial camera 7; the method comprises the steps of calibrating parameters in a camera and calibrating an optical plane equation:
the calibrating means comprises the following steps: halcon calibration or Zhang Zhengyou calibration;
calibrating to obtain:
wherein W is 2 ，W 1 Is a coordinate transformation matrix.
(2) The center coordinates of the CCD industrial camera 7 optical lenses and the end coordinates of the high-speed electric drive grinding wheel 2 are converted into matrix hand-eye calibration:
the CCD industrial camera 7 light mirror and the high-speed electric driving grinding wheel 2 are mechanically fixed, and the center coordinate of the CCD industrial camera 7 light mirror is at the origin (X) of the end coordinate of the high-speed electric driving grinding wheel 2 z ，Y z ，Z z ) Conversion matrix W 3 Constant fixed value, obtain:
(3) high-speed electric drive grinding wheel 2 end coordinates and grinding six-axis robot 1 base coordinate transformation matrix hand-eye calibration:
the high-speed electric driving grinding wheel 2 is mechanically fixed at the end part of the six-axis polishing robot 1, and the coordinates (X z ，Y z ，Z z ) The coordinates are at the origin (X) 0 ，Y 0 ，Z 0 ) Conversion matrix W 4 Constant fixed value, obtain:
finally, a point q on the picture taken by the CCD industrial camera 7 is obtained, and the pixel coordinates are (u q ，v q ) The calculation formula of the coordinates under the base standard system of the polishing robot is as follows:
(8) Determining the pose of a grinding head 3 of each frame of image: obtaining an X axis through a JA linear equation, obtaining a Y axis through a J point tangent linear equation obtained through a grinding track curve L, determining a Z axis through the X axis and the Y axis, thus obtaining a final three-dimensional coordinate system, enabling the included angle between the axis of the grinding head 3 and ZY and XY planes to be gamma, enabling the included angle between the axis of the grinding head 3 and the Y axis to be beta, enabling the end point of the grinding head 3 to coincide with the J point, obtaining the pose of the grinding head 3, setting the rotating speed and the grinding advancing speed of the grinding head 3, and transmitting the motion control parameters to a motion control system to realize the function of automatic control of grinding motion;
(9) Polishing a welding line: selecting a grinding head 3 with the radius not smaller than the EJ distance, and controlling the grinding head 3 to grind the weld seam according to the pose in the step (8) along the grinding track curve L obtained in the step (7).
The polishing equipment adopted in the implementation of the polishing method comprises a six-axis robot 1, a high-speed electric driving grinding wheel 2, an industrial personal computer 4, a robot controller 6, a CCD industrial camera 7 and a line laser generator 8, wherein the line laser generator 8 is used for polishing laser projection lines 9 on a welding seam structural member 5, the CCD industrial camera 7 is used for collecting pictures with the laser lines and transmitting the pictures to the industrial personal computer 4, the industrial personal computer 4 is used for executing relevant calculation in the steps and transmitting the result to the robot controller 6, and the robot controller 6 is used for controlling the six-axis robot 1 to polish.
Working principle:
the method comprises the steps of collecting weld images frame by utilizing laser projection lines 9, carrying out image processing on each frame of images to obtain geometric profile morphology of the weld, extracting characteristic points, establishing an initial three-dimensional coordinate system, judging whether undercut defects exist in each frame of images according to preset rules, respectively determining polishing starting points, end points and points which can be reached by the minimum polishing width according to relevant polishing standards after safety prediction according to different conditions, wherein the polishing end points can also be called actual action points, converting pixel coordinates of each frame of actual action points into three-dimensional coordinates under a base of a six-axis robot 1, fitting each frame of actual action point coordinates to obtain a polishing track curve, establishing a final three-dimensional coordinate system by taking tangent lines of each point on the polishing track curve as a Y axis of the point, and further calculating to obtain the polishing pose of each frame of image grinding head according to preset rules.
Finally, it should be noted that the above-mentioned embodiments are only for illustrating the technical scheme of the present invention and are not limiting; while the invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that: modifications may be made to the specific embodiments of the present invention or equivalents may be substituted for part of the technical features thereof; without departing from the spirit of the invention, it is intended to cover the scope of the invention as claimed.
Claims (6)
1. An intelligent toe mechanical polishing fatigue life-prolonging method is characterized by comprising the following steps:
(1) And (3) welding line scanning: scanning a weld to be polished frame by adopting a laser projection line, wherein a laser light plane is parallel to a weld cross section during scanning, and a laser central line is positioned on an equally divided plane of a plane included angle of a weld base material;
(2) Image processing: sequentially carrying out image preprocessing and central line extraction on the weld joint images scanned frame by frame to respectively obtain geometric profile shapes of the weld joint represented by the central line;
(3) Extracting characteristic points of each frame of image: respectively setting two end points of the geometric outline of the welding seam as a point A and a point B, wherein an initial three-dimensional coordinate system is established by taking a straight line of the point A on the geometric outline of the welding seam as an X axis and a direction perpendicular to a plane of the geometric outline of the welding seam as an ordinate, and setting a point with the lowest pixel point vertical coordinate and more than 20 pixels lower than the point A vertical coordinate as a point S; when the S point exists, the frame image has an undercut defect, a first endpoint is an H point from the A point, a second endpoint is a D point, and a first endpoint is a C point from the B point; when the S point does not exist, the frame image does not have undercut defect, and the first endpoint is the C point, and the second endpoint is the D point from the B point;
(4) Determining polishing start and end points of each frame of image: when the frame image has an undercut defect, taking a central point of a connecting line of a D point and an H point as a polishing initial action point J, and when the frame image does not have the undercut defect, taking the D point as the polishing initial action point J and taking the J point as an original point of an initial three-dimensional coordinate system; on the geometric outline of the welding seam, finding an E point from the D point to the B point, enabling the distance of D, E to be 1/2 of the size of a welding leg, and taking the E point as a polishing minimum width point; setting the thickness of a welding seam parent metal as d, setting the included angle between the axis of the grinding head and ZY and the included angle between the axis of the grinding head and the XY plane as gamma and setting the included angle between the axis of the grinding head and the Y axis as beta, and searching the N point of the deepest grinding point on the axis of the grinding head to ensure that NJ is approximately equal to fd/cos gamma, wherein the N point is the grinding end point, and f, gamma, beta and E points are all determined by grinding standards;
(5) And (5) grinding track calculation: converting the image coordinates of N points in each frame of image into three-dimensional coordinates under the base coordinates of the polishing robot, and performing quasi-uniform three-time B spline curve fitting on the coordinates of N points in each frame of image to obtain a polishing track curve L;
(6) Determining the pose of a grinding head of each frame of image: obtaining an X axis through a JA linear equation, obtaining a Y axis through a J point tangent linear equation obtained through grinding a track curve L, determining a Z axis through the X axis and the Y axis, so as to obtain a final three-dimensional coordinate system, wherein the included angle between the grinding head axis and ZY and XY planes is gamma, the included angle between the grinding head axis and the Y axis is beta, and the end point of the grinding head coincides with the J point, so that the pose of the grinding head is obtained;
(7) Polishing a welding line: and (3) selecting a grinding head with the radius not smaller than the EJ distance, and controlling the grinding head to grind the weld seam according to the pose in the step (6) along the grinding track curve L obtained in the step (5).
2. The method for intelligently polishing fatigue and prolonging life of a weld toe machine according to claim 1, wherein the method comprises the following steps: the image preprocessing in the step (3) comprises video frame taking, effective area positioning and extracting, ostu filtering and morphological trimming.
3. The method for intelligently polishing fatigue and prolonging life of a weld toe machine according to claim 2, wherein the method comprises the following steps: the method also comprises the step of obtaining a stress concentration area through actual finite element simulation, fatigue experiments or stress analysis and determining a welding line of the fatigue area.
4. An intelligent toe mechanical polishing fatigue life extension method according to any of claims 1-3, wherein: the method further comprises the step of safety prediction, wherein the included angle between the BC straight line and the AD straight line and the distance between the BC straight line and the line segment DC are calculated, and when the included angle is smaller than a threshold angle or the distance is smaller than the threshold value, the welding line is polished to have dangerousness, so that early warning is carried out.
5. The method for intelligently polishing fatigue and prolonging life of a weld toe machine according to claim 4, wherein the method comprises the following steps: in the step (5), a mode of combining structured light visual calibration and hand-eye calibration is adopted when the image coordinates are converted into three-dimensional coordinates under the base coordinates of the polishing robot.
6. The intelligent toe mechanical polishing fatigue life extension method according to any one of claims 1, 2, 3 and 5, wherein: and the gamma and the beta are both between 30 and 45 degrees.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111459823.7A CN114399461B (en) | 2021-12-02 | 2021-12-02 | Intelligent toe mechanical polishing fatigue life-prolonging method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111459823.7A CN114399461B (en) | 2021-12-02 | 2021-12-02 | Intelligent toe mechanical polishing fatigue life-prolonging method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114399461A CN114399461A (en) | 2022-04-26 |
| CN114399461B true CN114399461B (en) | 2023-07-25 |
Family
ID=81225669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111459823.7A Active CN114399461B (en) | 2021-12-02 | 2021-12-02 | Intelligent toe mechanical polishing fatigue life-prolonging method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114399461B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115592501A (en) * | 2022-10-11 | 2023-01-13 | 中国第一汽车股份有限公司（Cn） | Top cover brazing self-adaptive polishing method based on 3D line laser vision guidance |
| CN116652704B (en) * | 2023-07-28 | 2023-10-31 | 中国人民解放军空军工程大学 | Composite repair method for self-adapting to appearance of aircraft structure |
| CN116985143B (en) * | 2023-09-26 | 2024-01-09 | 山东省智能机器人应用技术研究院 | Polishing track generation system of polishing robot |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105844622A (en) * | 2016-03-16 | 2016-08-10 | 南京工业大学 | V-shaped groove weld joint detection method based on laser vision |
| CN107798330A (en) * | 2017-11-10 | 2018-03-13 | 上海电力学院 | A kind of weld image characteristics information extraction method |
| CN107876970A (en) * | 2017-12-13 | 2018-04-06 | 浙江工业大学 | A kind of robot multi-pass welding welding seam three-dimensional values and weld seam inflection point identification method |
| CN108132017A (en) * | 2018-01-12 | 2018-06-08 | 中国计量大学 | A kind of plane welded seam Feature Points Extraction based on laser vision system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110091333B (en) * | 2019-05-17 | 2022-05-06 | 上海交通大学 | Device and method for identifying and automatically grinding and polishing weld joint features on surface of complex curved surface |
| CN111103291A (en) * | 2019-12-20 | 2020-05-05 | 广西柳州联耕科技有限公司 | Image recognition and quality intelligent evaluation system based on product weld joint characteristics |
| CN112223293B (en) * | 2020-10-21 | 2022-08-09 | 湖南科技大学 | Online grinding method of welding line grinding and polishing robot |
| CN113063348B (en) * | 2021-03-15 | 2023-05-16 | 南京工程学院 | Structured light self-perpendicular arc welding seam scanning method based on three-dimensional reference object |
-
2021
- 2021-12-02 CN CN202111459823.7A patent/CN114399461B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105844622A (en) * | 2016-03-16 | 2016-08-10 | 南京工业大学 | V-shaped groove weld joint detection method based on laser vision |
| CN107798330A (en) * | 2017-11-10 | 2018-03-13 | 上海电力学院 | A kind of weld image characteristics information extraction method |
| CN107876970A (en) * | 2017-12-13 | 2018-04-06 | 浙江工业大学 | A kind of robot multi-pass welding welding seam three-dimensional values and weld seam inflection point identification method |
| CN108132017A (en) * | 2018-01-12 | 2018-06-08 | 中国计量大学 | A kind of plane welded seam Feature Points Extraction based on laser vision system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114399461A (en) | 2022-04-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114399461B (en) | Intelligent toe mechanical polishing fatigue life-prolonging method | |
| CN106041295B (en) | The control method and device of welding | |
| CN107150175B (en) | Damage the real-time dynamic cladding reparation of Gear by Laser and stress regulation and control system and method | |
| CN111618396A (en) | Multilayer and multi-pass welding device and method based on visual representation | |
| CN111192307A (en) | Self-adaptive deviation rectifying method based on laser cutting of three-dimensional part | |
| CN112238304B (en) | Method for automatically welding small-batch customized special-shaped bridge steel templates by mechanical arm based on image visual recognition of welding seams | |
| CN103231162A (en) | Device and method for visual detection of welding quality of robot | |
| CN112453703A (en) | Complex special-shaped structure remote laser welding method based on visual sensing | |
| CN114043045B (en) | Round hole automatic plug welding method and device based on laser vision | |
| CN113042953A (en) | Complex weld joint tracking device and method | |
| CN110508906A (en) | A kind of method that robotic laser displacement sensor seeks position | |
| CN111168288A (en) | Double-ring welding seam laser visual tracking system and tracking method | |
| CN117226154A (en) | Welding bead milling method and system based on 3D visual guidance | |
| CN114473153A (en) | Oil-gas long-distance pipeline welding system and method | |
| CN113063348B (en) | Structured light self-perpendicular arc welding seam scanning method based on three-dimensional reference object | |
| CN110842683A (en) | Welding seam grinding device and system based on machine vision | |
| WO2021111759A1 (en) | Repair welding device and repair welding method | |
| CN110560754B (en) | Self-adaptive machining system, control method thereof and vehicle body machining equipment | |
| CN115533380A (en) | Welding seam defect identification and automatic repair welding method | |
| CN116475665A (en) | Flaw detection structure, drill bit welding equipment special for drilling machine and welding method | |
| CN106881525A (en) | Laser Processing control system and its control method | |
| CN114689609A (en) | Tube panel weld defect detection device | |
| CN114714020A (en) | Groove weld welding method for multi-cavity steel member | |
| CN115246045A (en) | Laser welding method | |
| CN109978853B (en) | Method for calculating deviation between welding position and welding seam in linear welding seam laser tailor-welding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |