WELDING PROCESS

• US 20180065204A1
• Filed: 08/30/2017
• Published: 03/08/2018
• Est. Priority Date: 09/05/2016
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: BURROWS, Eliot
• Granted Patent: US 10,449,616 B2
• Time in Patent Office: Days
• CPC Class Codes: B21J 15/28 Control devices specially adapted to riveting machines not restricted to one of the preceding subgroups
• CPC Class Codes: B23K 31/02 relating to soldering or welding dip or wave soldering in the manufacture of printed circuits H05K3/34
• CPC Class Codes: B23K 9/0026 specially adapted for particular articles or work
• CPC Class Codes: B23K 9/126 Controlling the spatial relationship between the work and the gas torch between wire tip and piece B23K9/073
• CPC Class Codes: B23K 9/167 and of a non-consumable electrode
• CPC Class Codes: B25J 11/007 Riveting
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 19/4207 in which a model is traced or scanned and corresponding data recorded
• CPC Class Codes: G05B 2219/36401 Record play back, teach position and record it then play back
• CPC Class Codes: G05B 2219/45088 Riveting robot
• CPC Class Codes: G05B 2219/45135 Welding

Abstract

A method and apparatus for welding a first component to a second component. A scanning head is positionally calibrated within a localised work envelope including the components, the positional calibration being referenced to at least one datum feature within the work envelope. Profiles of the components are scanned within the localised work envelope using the calibrated scanning head. A cloud point data image of defined coordinate positions of surfaces and edges to be welded within a space envelope is generated from the scanned profiles. A robotic welding torch electrode tip is scanned using the calibrated scanning head to determine a defined coordinate position of the electrode tip within the space envelope. The components are welded using the torch, the torch controlled using the cloud point data image and the defined coordinate position such that the electrode tip is held at pre-determined stand-off positions around the components during the welding.

Claims

1. A method for welding a first component to a second component, including:

positionally calibrating a scanning head within a localised work envelope including the first component and the second component, the positional calibration being referenced to at least one datum feature within the work envelope;

scanning profiles of the first component and the second component within the localised work envelope using the calibrated scanning head;

generating from the scanned profiles a cloud point data image of defined coordinate positions of surfaces and edges to be welded within a space envelope;

scanning an electrode tip of a robotic welding torch using the calibrated scanning head to determine a defined coordinate position of the electrode tip within the space envelope; and

welding the first component to the second component using the robotic welding torch, wherein the robotic welding torch is controlled using the cloud point data image and the defined coordinate position of the electrode tip such that the electrode tip is held at pre-determined stand-off positions around the components during the welding.

2. The method of claim 1 wherein the scanning head is positionally calibrated along x, y, z linear orthogonal axes within the localised work envelope.

3. The method of claim 1 further including, before positionally calibrating the scanning head, positioning the scanning head by reference to a master theoretical model of the first and second components'"'"' positions within the space envelope.

4. The method of claim 1 wherein the scanning head is attached to a robotic arm having a first orientation for scanning profiles of the first component and the second component, and a second orientation for scanning the electrode tip.

5. The method of claim 1 further including determining, from the cloud point data image of surfaces and edges to be welded, whether predetermined weld joint characteristics are satisfied, such that the welding of the first component to the second component can be stopped in the case that predetermined weld joint characteristics are not satisfied.

6. The method of claim 1 wherein the scanning head includes a 3D optical visualiser.

7. The method of claim 1 wherein the welding is tungsten inert gas (TIG) welding.

8. A computer control system programmed to control a scanning head and a robotic welding torch to perform the method of claim 1.

9. An apparatus for welding a first component to a second component, including:

a scanning head;

a robotic welding torch; and

the computer control system of claim 8.

10. A computer program comprising code which, when run on a computer, causes the computer to control a scanning head and a robotic welding torch to perform the method of claim 1.

11. A computer readable medium storing the computer program of claim 10.

12. An apparatus for welding a first component to a second component, including:

a scanning head;

a robotic welding torch; and

a computer control system;

wherein the computer control system is programmed to;

positionally calibrate the scanning head within a localised work envelope including the first component and the second component, the positional calibration being referenced to at least one datum feature within the work envelope;

use the scanning head to scan profiles of the first component and the second component within the localised work envelope using the calibrated scanning head;

generate from the scanned profiles a cloud point data image of defined coordinate positions of surfaces and edges to be welded within a space envelope;

use the scanning head to scan an electrode tip of the robotic welding torch to determine a defined coordinate position of the electrode tip within the space envelope; and

use the robotic welding torch to weld the first component to the second component, wherein the robotic welding torch is controlled by the control system using the cloud point data image and the defined coordinate position of the electrode tip such that the electrode tip is held at pre-determined stand-off positions around the components during the welding.

13. A method for mechanically fastening a first component to a second component, including:

positionally calibrating a scanning head within a localised work envelope including the first component and the second component, the positional calibration being referenced to at least one datum feature within the work envelope;

scanning profiles of the first component and the second component within the localised work envelope using the calibrated scanning head;

generating from the scanned profiles a cloud point data image of defined coordinate positions of surfaces and edges to be assembled within a space envelope;

scanning a fastening tool (e.g. a handling gripper, rivet gun etc.) of a robotic mechanical fastener using the calibrated scanning head to determine a defined coordinate position of the fastening tool within the space envelope; and

fastening the first component to the second component using the robotic mechanical fastener, wherein the robotic mechanical fastener is controlled using the cloud point data image and the defined coordinate position of the fastening tool such that the fastening tool is held at pre-determined stand-off positions around the components during the fastening.

14. The method of claim 13 wherein mechanically fastening comprises riveting and the fastening tool comprises a rivet gun.

15. The method of claim 13 wherein mechanically fastening comprises bolting and the fastening tool comprises a handling gripper.

16. An apparatus for mechanically fastening a first component to a second component, including:

a scanning head;

a robotic mechanical fastener; and

a computer control system;

wherein the computer control system is programmed to;

positionally calibrate the scanning head within a localised work envelope including the first component and the second component, the positional calibration being referenced to at least one datum feature within the work envelope;

use the scanning head to scan profiles of the first component and the second component within the localised work envelope using the calibrated scanning head;

generate from the scanned profiles a cloud point data image of defined coordinate positions of surfaces and edges to be assembled within a space envelope;

use the scanning head to scan a fastening tool of the robotic mechanical fastener to determine a defined coordinate position of the fastening tool within the space envelope; and

use the robotic mechanical fastener to fasten the first component to the second component, wherein the robotic mechanical fastener is controlled by the control system using the cloud point data image and the defined coordinate position of the fastening tool such that the fastening tool is held at pre-determined stand-off positions around the components during the fastening.

17. The apparatus of claim 16 wherein the apparatus comprises a riveting apparatus and the fastening tool comprises a rivet gun.

18. The apparatus of claim 16 wherein the apparatus comprises a bolting apparatus and the fastening tool comprises a handling gripper.