CN111390421A - Welding method - Google Patents
Welding method Download PDFInfo
- Publication number
- CN111390421A CN111390421A CN201811648604.1A CN201811648604A CN111390421A CN 111390421 A CN111390421 A CN 111390421A CN 201811648604 A CN201811648604 A CN 201811648604A CN 111390421 A CN111390421 A CN 111390421A
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- welding
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- product
- welded
- track
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K33/00—Specially-profiled edge portions of workpieces for making soldering or welding connections; Filling the seams formed thereby
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/16—Arc welding or cutting making use of shielding gas
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/32—Accessories
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- 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
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/50—Depth or shape recovery
- G06T7/55—Depth or shape recovery from multiple images
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/80—Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
- G06T7/85—Stereo camera calibration
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- 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
- G06T2207/10—Image acquisition modality
- G06T2207/10028—Range image; Depth image; 3D point clouds
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- 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
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- 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
- G06T2207/30241—Trajectory
Abstract
The invention relates to a welding method, which obtains image information of a product to be welded through an industrial camera and a line laser, associates a three-dimensional model of the product to be welded on the industrial camera with coordinates of a welding machine, can convert contour coordinates of the three-dimensional model into motion track coordinates of the welding machine, and directly drives the welding machine to run along the welding track through a motion control program on an industrial personal computer for welding. The invention does not need to write a motion control program in advance, and has strong universality; in addition, the invention automatically acquires images through the industrial camera and obtains the running track of the welding machine through coordinate conversion, so that errors caused by the tool and the errors of the product can be compensated during welding, and the welding precision is improved.
Description
Technical Field
The invention relates to the field of automatic control, in particular to a welding method.
Background
Most of traditional welding robots walk along teaching tracks of the robots, the robots always weld according to programs which are taught in advance, and the welding tracks cannot be adjusted in real time according to production differences of products, so that the welding precision is generally low. In the actual application process, because the product is numerous, the product to each different grade type all needs to teach once, brings very big work load for the staff, wherein still can be because the type of product differs, need redesign customization processing special fixture to fix a position for the product, and anchor clamps design processing cost is high, and whole welding system's commonality is not strong.
Disclosure of Invention
Therefore, it is necessary to provide a welding method for overcoming the defects of low welding accuracy and low versatility.
A method of welding, comprising: placing a product to be welded on a conveyor belt, polishing the product to be welded by a line laser when the product to be welded moves to a visual detection area, and photographing the product to be welded by an industrial camera to obtain image information of the product to be welded;
the image information is transmitted to a visual industrial personal computer and is processed by a visual algorithm program;
a visual algorithm program extracts a welding track of a product to be welded and acquires a welding track coordinate;
moving a product to be welded to a welding area through a conveyor belt, performing hand-eye calibration through the relation between the pixel coordinates of an industrial camera image and the tail end of a welding machine, and converting the welding track coordinates into the motion track coordinates of the tail end of the welding machine;
and the visual industrial personal computer drives the welding machine to run along the motion track according to the motion track coordinates of the tail end of the welding machine, so as to complete welding.
According to the technical scheme, the image information of a product to be welded is obtained through the industrial camera and the line laser, the three-dimensional model of the product to be welded on the industrial camera is associated with the coordinates of the welding machine, the contour coordinates of the three-dimensional model can be converted into the motion track coordinates of the welding machine, and the motion control program on the industrial personal computer directly drives the welding machine to move along the welding track through the welding track given by the visual program to carry out welding. The technical scheme does not need to write a motion control program in advance, and has strong universality; in addition, according to the technical scheme, the image is automatically acquired through the industrial camera, the running track of the welding machine is acquired through coordinate conversion, errors caused by the tool and errors of products can be compensated during welding, and the welding precision is improved.
Further, the method for acquiring the welding track coordinates comprises the following steps: the industrial camera obtains data information of an X axis and a Z axis of an image of a product to be welded at the position of the laser line, the distance S = V/P between adjacent laser lines can be calculated through the transmission speed V of the conveyor belt and the photographing frequency P of the industrial camera, and data information of a Y axis of the image of the product to be welded at the position of the laser line can be calculated through the distance S between the adjacent laser lines.
Further, the welding track coordinate is a welding track coordinate subjected to spline curve fitting.
Further, the spline curve fitting adopts quadratic spline curve fitting.
Further, the specific steps of fitting the quadratic spline curve are as follows:
determining a quadratic spline curve fitting formula: d (x) = Ax + Bx + Cx (0. ltoreq. x.ltoreq.1);
acquiring coordinates of three points D1, D2 and D3 in a contour edge of a welding pattern, wherein D1 is a starting point of the contour edge, D3 is an end point of the contour edge, when x =0.5, the contour edge passes through D2 points, and a tangent vector is D3-D1; the value of A, B, C was determined by D1, D2, D3, completing a quadratic spline curve fit.
Further, the three-dimensional hand-eye calibration comprises the following specific steps:
placing the three-dimensional calibration block in a visual detection area, and photographing the three-dimensional calibration block through an industrial camera to obtain pixel coordinates (x, y, z) of at least three non-coplanar corner points on the three-dimensional calibration block image on a three-dimensional point cloud;
the three-dimensional calibration block is moved to the tail end of a welding machine through a conveyor belt, and coordinates (u, v, w) of corresponding angular points on the three-dimensional calibration block are obtained through manual calibration;
the coordinate change matrix R from the pixel coordinates of the three-dimensional point cloud to the tail end of the welding machine is calculated as follows
R=（x，y，z，1）-1 •（u，v，w，1）；
And the transformation of the image pixel coordinates in the industrial camera and the coordinates of the tail end running track of the welding machine is completed through the change matrix R.
Further, the welder is a gas shielded welding welder.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
A method of welding, comprising: placing a product to be welded on a conveyor belt, polishing the product to be welded by a line laser when the product to be welded moves to a visual detection area, and photographing the product to be welded by an industrial camera to obtain image information of the product to be welded;
the image information is transmitted to a visual industrial personal computer and is processed by a visual algorithm program;
a visual algorithm program extracts a welding track of a product to be welded and acquires a welding track coordinate;
moving a product to be welded to a welding area through a conveyor belt, performing hand-eye calibration through the relation between the pixel coordinates of an industrial camera image and the tail end of a welding machine, and converting the welding track coordinates into the motion track coordinates of the tail end of the welding machine;
and the visual industrial personal computer drives the welding machine to run along the motion track according to the motion track coordinates of the tail end of the welding machine, so as to complete welding.
According to the embodiment, the image information of the product to be welded is obtained through the industrial camera and the line laser, the three-dimensional model of the product to be welded on the industrial camera is associated with the coordinates of the welding machine, the contour coordinates of the three-dimensional model can be converted into the motion track coordinates of the welding machine, and the motion control program on the industrial personal computer directly drives the welding machine to move along the welding track through the welding track given by the visual program to weld. The implementation mode does not need to write a motion control program in advance, and has strong universality; in addition, the image is automatically acquired through the industrial camera, the running track of the welding machine is acquired through coordinate conversion, errors caused by the tool and errors of products can be compensated during welding, and the welding precision is improved.
Further, the method for acquiring the welding track coordinates comprises the following steps: the industrial camera obtains data information of an X axis and a Z axis of an image of a product to be welded at the position of the laser line, the distance S = V/P between adjacent laser lines can be calculated through the transmission speed V of the conveyor belt and the photographing frequency P of the industrial camera, and data information of a Y axis of the image of the product to be welded at the position of the laser line can be calculated through the distance S between the adjacent laser lines. And forming point cloud data of three-dimensional information by combining the data information of the X axis, the Y axis and the Z axis of the image so as to obtain three-dimensional model data of the product to be welded.
Further, the welding track coordinate is a welding track coordinate subjected to spline curve fitting, namely the welding track coordinate is a smooth curve contour information coordinate. Because the information of the product outline edge directly acquired by the industrial camera through photographing is not smooth, the final welding precision is influenced, so that spline curve fitting is performed on the information of the product outline edge to be welded, smooth curve outline information is formed, and the welding precision is improved.
Furthermore, the spline curve fitting adopts secondary spline curve fitting, the fitting difficulty is low, and the requirement of the embodiment can be met.
Further, the specific steps of fitting the quadratic spline curve are as follows:
determining a quadratic spline curve fitting formula: d (x) = Ax + Bx + Cx (0. ltoreq. x.ltoreq.1);
acquiring coordinates of three points D1, D2 and D3 in a contour edge of a welding pattern, wherein D1 is a starting point of the contour edge, D3 is an end point of the contour edge, when x =0.5, the contour edge passes through D2 points, and a tangent vector is D3-D1; the value of A, B, C was determined by D1, D2, D3, completing a quadratic spline curve fit.
Further, the three-dimensional hand-eye calibration comprises the following specific steps:
placing the three-dimensional calibration block in a visual detection area, and photographing the three-dimensional calibration block through an industrial camera to obtain pixel coordinates (x, y, z) of at least three non-coplanar corner points on the three-dimensional calibration block image on a three-dimensional point cloud;
the three-dimensional calibration block is moved to the tail end of a welding machine through a conveyor belt, and coordinates (u, v, w) of corresponding angular points on the three-dimensional calibration block are obtained through manual calibration;
the coordinate change matrix R from the pixel coordinates of the three-dimensional point cloud to the tail end of the welding machine is calculated as follows
R=（x，y，z，1）-1 •（u，v，w，1）；
And the transformation of the image pixel coordinates in the industrial camera and the coordinates of the tail end running track of the welding machine is completed through the change matrix R.
In the embodiment, the pixel coordinates of the image of not less than three points and the corresponding coordinates of the tail end of the welding machine are respectively obtained through the three-dimensional calibration block to obtain the value of the change matrix R; for example, the present embodiment employs three point cloud pixel coordinates (x 1, y1, z 1), (x 2, y2, z 2), (x 3, y3, z 3); coordinates of the respective welder tip (u 1, v1, w 1), (u 2, v2, w 2), (u 3, v3, w 3).
Furthermore, the welding machine is a gas shielded welding machine, the operation is simple, the arc striking is easy, and the electric arc is stable.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (7)
1. A method of welding, comprising: placing a product to be welded on a conveyor belt, polishing the product to be welded by a line laser when the product to be welded moves to a visual detection area, and photographing the product to be welded by an industrial camera to obtain image information of the product to be welded;
the image information is transmitted to a visual industrial personal computer and is processed by a visual algorithm program;
a visual algorithm program extracts a welding track of a product to be welded and acquires a welding track coordinate;
moving a product to be welded to a welding area through a conveyor belt, performing hand-eye calibration through the relation between the pixel coordinates of an industrial camera image and the tail end of a welding machine, and converting the welding track coordinates into the motion track coordinates of the tail end of the welding machine;
and the visual industrial personal computer drives the welding machine to run along the motion track according to the motion track coordinates of the tail end of the welding machine, so as to complete welding.
2. The welding method according to claim 1, wherein the welding track coordinates are obtained by: the industrial camera obtains data information of an X axis and a Z axis of an image of a product to be welded at the position of the laser line, the distance S = V/P between adjacent laser lines can be calculated through the transmission speed V of the conveyor belt and the photographing frequency P of the industrial camera, and data information of a Y axis of the image of the product to be welded at the position of the laser line can be calculated through the distance S between the adjacent laser lines.
3. The welding method of claim 1, wherein the welding trajectory coordinates are spline curve fitted welding trajectory coordinates.
4. The welding method of claim 3, wherein the spline curve fit is a quadratic spline curve fit.
5. The welding method according to claim 3, wherein the fitting of the quadratic spline curve is performed by the following steps:
determining a quadratic spline curve fitting formula: d (x) = Ax + Bx + Cx (0. ltoreq. x.ltoreq.1);
acquiring coordinates of three points D1, D2 and D3 in a contour edge of a welding pattern, wherein D1 is a starting point of the contour edge, D3 is an end point of the contour edge, when x =0.5, the contour edge passes through D2 points, and a tangent vector is D3-D1; the value of A, B, C was determined by D1, D2, D3, completing a quadratic spline curve fit.
6. The welding method according to claim 1, characterized in that the three-dimensional hand-eye calibration comprises the following specific steps:
placing the three-dimensional calibration block in a visual detection area, and photographing the three-dimensional calibration block through an industrial camera to obtain pixel coordinates (x, y, z) of at least three non-coplanar corner points on the three-dimensional calibration block image on a three-dimensional point cloud;
the three-dimensional calibration block is moved to the tail end of a welding machine through a conveyor belt, and coordinates (u, v, w) of corresponding angular points on the three-dimensional calibration block are obtained through manual calibration;
the coordinate change matrix R from the pixel coordinates of the three-dimensional point cloud to the tail end of the welding machine is calculated as follows
R=（x，y，z，1）-1 •（u，v，w，1）；
And the transformation of the image pixel coordinates in the industrial camera and the coordinates of the tail end running track of the welding machine is completed through the change matrix R.
7. The welding method of claim 1, wherein the welder is a gas shielded welding welder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811648604.1A CN111390421A (en) | 2018-12-30 | 2018-12-30 | Welding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811648604.1A CN111390421A (en) | 2018-12-30 | 2018-12-30 | Welding method |
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| Publication Number | Publication Date |
|---|---|
| CN111390421A true CN111390421A (en) | 2020-07-10 |
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| CN201811648604.1A Pending CN111390421A (en) | 2018-12-30 | 2018-12-30 | Welding method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112222654A (en) * | 2020-08-31 | 2021-01-15 | 佛山市三高保温水箱有限公司 | Welding process for enamel inner container of water heater |
| CN114559174A (en) * | 2022-03-28 | 2022-05-31 | 重庆数码模车身模具有限公司 | Automatic welding method for new energy automobile battery tray |
-
2018
- 2018-12-30 CN CN201811648604.1A patent/CN111390421A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112222654A (en) * | 2020-08-31 | 2021-01-15 | 佛山市三高保温水箱有限公司 | Welding process for enamel inner container of water heater |
| CN114559174A (en) * | 2022-03-28 | 2022-05-31 | 重庆数码模车身模具有限公司 | Automatic welding method for new energy automobile battery tray |
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Application publication date: 20200710 |
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