OPTICAL-BASED WELD TRAVEL SPEED SENSING SYSTEM

• US 20130206740A1
• Filed: 01/14/2013
• Published: 08/15/2013
• Est. Priority Date: 02/10/2012
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Pfeifer, Kyle Andrew, Holverson, Todd Earl, Watson, William Todd, Hutchison, Richard Martin, Becker, William Joshua
• Granted Patent: US 9,522,437 B2
• Time in Patent Office: Days
• US Class Current: 219/124.5
• CPC Class Codes: B23K 9/095 Monitoring or automatic control of welding parameters
• CPC Class Codes: B23K 9/0953 using computing means
• CPC Class Codes: B23K 9/0956 using sensing means, e.g. optical
• CPC Class Codes: G01P 3/36 Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light G01P3/68 takes precedence; gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams G01C19/64
• CPC Class Codes: G01P 3/38 using photographic means
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 11/14 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems

Abstract

A travel speed sensing system includes an optical sensor configured to be coupled to a welding torch. The optical sensor is configured to sense light incident on the optical sensor, and the travel speed sensing system is configured to determine a travel speed of the welding torch, a direction of the welding torch, or both, based on the sensed light.

Claims

1. A travel speed sensing system, comprising:

an optical sensor configured to be coupled to a welding torch, wherein the optical sensor is configured to sense light incident on the optical sensor, and wherein the travel speed sensing system is configured to determine a travel speed of the welding torch, a direction of the welding torch, or both, based on the sensed light.

2. The travel speed sensing system of claim 1, wherein the optical sensor comprises a range finding mechanism configured to determine a distance from the optical sensor to a surface, and wherein the travel speed sensing system is configured to determine the travel speed based on the distance.

3. The travel speed sensing system of claim 1, wherein the travel speed sensing system is configured to determine the travel speed using optical flow algorithms applied to images acquired via the optical sensor.

4. The travel speed sensing system of claim 1, wherein the optical sensor is configured to acquire images of a surface in a weld area to determine the travel speed of the welding torch.

5. The travel speed sensing system of claim 4, wherein the surface is augmented by application of a visible pattern to the surface, and the optical sensor is configured to determine the travel speed of the welding torch based on the pattern.

6. The travel speed sensing system of claim 1, comprising a positioning mechanism configured to maintain the optical sensor at a specific distance relative to a surface in a weld area across a range of positions of the welding torch relative to the workpiece.

7. The travel speed sensing system of claim 1, comprising an optical surface motion sensor having the optical sensor and a light source, wherein the optical surface motion sensor is configured to:

output light toward a surface in a weld area via the light source; and

sense light reflected from the surface via the optical sensor.

8. The travel speed sensing system of claim 7, comprising:

a first optical fiber configured to carry the light output from the light source toward the surface; and

a second optical fiber configured to carry the light reflected from the surface to the optical sensor.

9. The travel speed sensing system of claim 7, wherein the optical surface motion sensor is configured to filter the light reflected from the surface via a filter to produce a filtered light at one or more desired frequencies, and sense the filtered light via the optical sensor.

10. The travel speed sensing system of claim 1, comprising multiple optical sensors coupled to different sides of the welding torch, wherein the multiple optical sensors are configured to provide surface motion information for determining the travel speed of the welding torch.

11. The travel speed sensing system of claim 1, comprising a sensor disposed on the welding torch, wherein the sensor is configured to sense a parameter indicative of an angle of the welding torch, and wherein the travel speed sensing system is configured to determine the travel speed based in part on the sensed parameter.

12. The travel speed sensing system of claim 1, comprising a protective covering disposed over the optical sensor to shield the optical sensor from weld spatter.

13. A welding torch assembly, comprising:

a welding torch configured to generate a welding arc between the welding torch and a workpiece; and

an optical sensor coupled to the welding torch and configured to output a signal indicative of light sensed by the optical sensor to a travel speed sensing system, wherein the travel speed sensing system is configured to determine a travel speed of the welding torch based on the signal.

14. The welding torch assembly of claim 13, wherein the optical sensor is configured to sense light reflected from a surface in a weld area.

15. The welding torch assembly of claim 14, comprising a surface motion sensing module coupled to the welding torch, wherein the surface motion sensing module comprises a light source to output light to the surface and the optical sensor to sense light reflected from the surface.

16. The welding torch assembly of claim 15, comprising a positioning mechanism configured to couple the surface motion sensing module to the welding torch, wherein the position mechanism maintains a position of the surface motion sensing module relative to the surface.

17. The welding torch assembly of claim 15, comprising:

a first optical fiber configured to carry the light output from the light source toward the surface; and

a second optical fiber configured to carry the light reflected from the surface to the optical sensor.

18. The welding torch assembly of claim 13, wherein the optical sensor comprises a camera configured to acquire images of a surface in a weld area, and the signal output from the camera to the travel speed sensing system comprises image data.

19. The welding torch assembly of claim 18, wherein the camera maintains a line of sight that is substantially parallel with a tip of the welding torch.

20. The welding torch assembly of claim 18, wherein the camera is configured to avoid saturation of the acquired images due to light from the welding arc.

21. The welding torch assembly of claim 18, wherein the travel speed sensing system is configured to process the images acquired via the camera to determine an image with a desired exposure.

22. A welding system, comprising:

a travel speed sensing system, comprising an array of optical sensors disposed about a weld area, wherein the optical sensors are configured to sense light emitted from a welding arc produced by the welding torch, and wherein the travel speed sensing system is configured to determine a travel speed of the welding torch based on the sensed light.