Method for circumferential welding and a robotic welding system for circumferential welding

Patent metadata

Field	Value
Publication number	US-10835981-B2
Application number	US-201715850739-A
Country	US
Kind code	B2
Filing date	Dec 21, 2017
Priority date	Dec 21, 2017
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A method for automated circumferential welding of a workpiece by means of at least one welding device, including: (a) determining a further weld path for a further weld to be welded on the workpiece, the further weld extending from a start point, via a downstream part to a stop point, (b) determining first welding parameters associated with the further weld and adapted to weld the further weld on the workpiece, the first welding parameters are adapted to transfer a first level of heat to the workpiece, (c) identifying at least one overlap area in the further weld path between the downstream part and the start point of the further weld or between the further weld and a start or stop point of a previous weld, (d) determining a boost area, the boost area including the at least one overlap area, (e) determining boost welding parameters associated with the boost area and adapted to weld the further weld in the boost area, the boost welding parameters are adapted to transfer a second level of heat to the workpiece, the second level of heat exceeding the first level of heat, and (f) welding the further weld from the start point to the stop point thereof, the first welding parameters are selected for welding of the further weld outside the boost area, and the boost welding parameters are selected for welding the further weld inside the boost area.

First claim

The invention claimed is:

1. A method for automated circumferential welding of a workpiece by means of at least one welding device, comprising the steps of:
a) determining a further weld path for a further weld to be welded on the workpiece, the further weld extending from a start point, via a downstream part to a stop point,
b) determining first welding parameters associated with said further weld and adapted to weld said further weld on the workpiece, wherein the first welding parameters are adapted to transfer a first level of heat to the workpiece,
c) identifying at least one overlap area in the further weld path between the downstream part and the start point of said further weld or between said further weld and a start or stop point of a previous weld,
d) determining a boost area, said boost area comprising said at least one overlap area,
e) determining boost welding parameters associated with said boost area and adapted to weld said further weld in said boost area, wherein the boost welding parameters are adapted to transfer a second level of heat to the workpiece, the second level of heat exceeding the first level of heat, and
f) welding the further weld from the start point to the stop point thereof, wherein the first welding parameters are selected for welding of the further weld outside said boost area, and wherein the boost welding parameters are selected for welding the further weld inside said boost area.

2. The method according to claim 1 , further comprising the step of:
g) identifying a second overlap area in the further weld path between the downstream part and the start point of said further weld or between said further weld and a start or stop point of a previous weld, wherein said boost area comprises said second overlap area.

3. The method according to claim 1 , wherein determining a further weld path for a further weld to be welded on the workpiece, comprises the steps:
h) identifying the position of the start point and/or the stop point of a previous weld on the workpiece, and
i) selecting the start point for the further weld to be offset from the start and/or stop point of said previous weld on the workpiece.

4. The method according to claim 3 , wherein determining a further weld path for a further weld to be welded on the workpiece further comprises the step of:
j) selecting the stop point for the further weld to be offset from the start and/or stop point of said previous weld on the workpiece.

5. The method according to claim 3 , wherein said start point for the further weld is selected to be in the interval of 5°-15°, preferably 10°, offset from respectively the start point or the stop point of said previous weld.

6. The method according to claim 1 , wherein determining a boost area comprises the step of:
k) determining a boost begin point upstream from said at least one overlap area in the weld path for the further weld.

7. The method according to claim 6 , wherein determining a boost area further comprises the step of:
l) determining a boost end point downstream from said at least one overlap area in the weld path for the further weld.

8. The method according to claim 6 , wherein the boost begin point is selected to be in the interval of 1°-3°, preferably 2°, upstream from said at least one overlap area.

9. The method according to claim 7 , wherein the boost end point is selected to be in the interval of 1°-3°, preferably 2°, downstream from said at least one overlap area.

10. The method according to claim 1 , wherein the method is performed by using a welding device comprising a control system with a memory, and wherein identifying at least one overlap area comprises the steps of:
m) storing in the memory of the control system the position of the start point and the stop point of a previous weld,
n) storing in the memory of the control system the determined weld path for the further weld,
o) using the control system to compare the position of the start point and the stop point of the previous weld with the determined weld path for the further weld, and
p) using the result of the comparison of o) to determine the position of the start point and/or stop point of the previous weld within the further weld path to thereby identify the at least one overlap area.

11. The method according to claim 1 , wherein identifying at least one overlap area in the further weld path between the start point of said further weld and a downstream part of said further weld or between a start or stop point of a previous weld and a part of said further weld comprises the steps of:
q) providing the welding device with a sensor adapted to obtain, during welding, information relating the weld path upstream from the welding device, and
r) analysing the information obtained in q) to identify the presence of a start point and/or the stop point of a previous weld in the weld path for the further weld.

12. The method according to claim 11 , wherein the method comprises the steps of:
s) providing the welding device with a camera adapted to obtain images of the weld path upstream from the welding device,
t) performing image processing of the obtained images obtained in s), and
u) using the results of the image processing of t) to determine the position of a start point and/or a stop point of a previous weld in the weld path for the further weld.

13. The method according to claim 1 , wherein the first welding parameters comprise at least a first welding power and wherein determining boost welding parameters comprises the step of:
v) obtaining boost power parameters to allow an increased transfer of heat to the workpiece during welding using the boost welding parameters compared to welding using the first welding parameters.

14. The method according to claim 1 , wherein the first welding parameters comprise at least a first angular orientation of the welding device with respect to the work piece and wherein determining boost welding parameters for the boost interval comprises the step of:
w) obtaining a boosted angular orientation of the welding head with respect to the work piece to allow an increased transfer of heat to the workpiece during welding using said boosted angular orientation compared to welding using the first welding parameters.

15. The method according to claim 1 , wherein the method comprises: repeating steps a)-f) to obtain a subsequent weld.

16. A computer program product comprising a computer-readable storage medium having encoded thereon computer-readable instructions, which, when executed by a computer, cause the computer to perform each of the method steps of claim 1 .

Assignees

• Technip France

Inventors

• Troyer Joel
• Brisac Gaspard

Classifications

• B23K2101/10

  Pipe-lines · CPC title

• B23K37/0229

  the guide member being situated alongside the workpiece · CPC title

• B23K9/124

  Circuits or methods for feeding welding wire · CPC title

• B23K9/295

  using consumable wire electrodes · CPC title

• B23K9/0286 Primary

  with an electrode moving around the fixed tube during the welding operation · CPC title