OPTICAL-BASED WELD TRAVEL SPEED SENSING SYSTEM

• US 20170095873A1
• Filed: 12/19/2016
• Published: 04/06/2017
• 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 11,612,949 B2
• Time in Patent Office: Days
• 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, the optical sensor is configured to acquire images of a surface in a weld area, the travel speed sensing system is configured to determine the travel speed of the welding torch based on the images.

2. 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 the images acquired via the optical sensor.

3. The travel speed sensing system of claim 1, 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 visible pattern.

4. 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 the surface in the weld area via the light source; and

sense light reflected from the surface via the optical sensor.

5. The travel speed sensing system of claim 4, 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.

6. The travel speed sensing system of claim 4, 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.

7. 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.

8. 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 parameter indicative of the angle of the welding torch.

9. 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.

10. 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 indicative of the light.

11. The welding torch assembly of claim 10, wherein the optical sensor is configured to sense light reflected from a surface in a weld area.

12. The welding torch assembly of claim 11, 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.

13. The welding torch assembly of claim 12, 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.

14. The welding torch assembly of claim 11, wherein the optical sensor comprises a camera configured to acquire images of the surface in the weld area, and the signal output from the camera to the travel speed sensing system comprises image data.

15. The welding torch assembly of claim 14, wherein the camera maintains a line of sight that is substantially parallel with a tip of the welding torch.

16. The welding torch assembly of claim 14, wherein the travel speed sensing system is configured to process the images acquired via the camera to determine an image with a desired exposure and to adjust an exposure time of the camera based on the desired exposure.

17. A welding system, comprising:

a travel speed sensing system, comprising an array of cameras disposed about a weld area, wherein the array of cameras are configured to acquire images of a welding arc produced by a welding torch, and wherein the travel speed sensing system is configured to determine a travel speed of the welding torch based on the images.

18. The welding system of claim 17, wherein a line of sight of at least one camera of the array of cameras intersects the welding arc.

19. The welding system of claim 17, wherein at least one camera of the array of cameras comprises a dual imager stereo camera.

20. The welding system of claim 17, wherein the travel speed sensing system is configured to triangulate a location of the welding arc based on the images and to determine the travel speed of the welding torch by monitoring changes in the location of the welding arc over time.