Welding process

• US 10,449,616 B2
• Filed: 08/30/2017
• Issued: 10/22/2019
• 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
• Primary Examiner(s): Kasenge, Charles R
• Application Number:
  US15/690,787
• Publication Number:
  US 20180065204A1
• Time in Patent Office: 783 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, the method comprising:

positionally calibrating a scanning head within a localised work envelope, the work envelope being defined by boundaries surrounding 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 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 of the first component and the second component to be welded within a space envelope, the space envelope being larger than the work envelope, which is located inside the 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, the electrode tip of the robotic welding torch being located outside of the work envelope at a time of scanning the electrode tip; and

welding the first component to the second component using the robotic welding torch, movement of the robotic welding torch being controlled using the cloud point data image and the defined coordinate position of the electrode tip, such that the electrode tip is held at a plurality of pre-determined stand-off positions around the first component and the second component within the work envelope 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 comprising, before positionally calibrating the scanning head, positioning the scanning head by reference to a master theoretical model of the position of the first component and the position of the second component 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 comprising 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 is stopped in response to determining that the 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 the scanning head and the robotic welding torch to perform the method of claim 1.

9. An apparatus for welding the first component to the second component, the apparatus comprising:

the scanning head;

the robotic welding torch; and

the computer control system of claim 8.

10. A non-transitory computer readable storage medium storing a computer program to be executed on a computer, causing the computer to control the scanning head and the robotic welding torch to perform the method of claim 1.

11. An apparatus for welding a first component to a second component, the apparatus comprising:

a scanning head;

a robotic welding torch; and

a computer control system programmed to;

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

control the scanning head to scan profiles of the first component and the second component within the 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 of the first component and the second component to be welded within a space envelope, the space envelope being larger than the work envelope, which is located inside the space envelope;

control 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, the electrode tip of the robotic welding torch being located outside of the work envelope at a time of scanning the electrode tip; and

control the robotic welding torch to weld the first component to the second component, movement of the robotic welding torch being 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 a plurality of pre-determined stand-off positions around the first component and the second component within the work envelope during the welding.