System and method of active torch marker control

• US 10,402,959 B2
• Filed: 10/30/2015
• Issued: 09/03/2019
• Est. Priority Date: 11/05/2014
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Becker, William Joshua, Weber, Jeffrey Dale
• Primary Examiner(s): Kalapodas, Dramos
• Application Number:
  US14/928,657
• Publication Number:
  US 20160125593A1
• Time in Patent Office: 1,404 Days
• CPC Class Codes: B23K 31/00 Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups making tubes or profiled bars involving operations other than soldering or welding B21C37/04, B21C37/08
• CPC Class Codes: B23K 37/00 Auxiliary devices or processes, not specially adapted to a procedure covered by only one of the preceding main groups eye-shields for welders worn on the operator's body or carried in the hand A61F9/00 , i.e. A61F9/02; applicable to metal-working machines other than soldering, welding, or flame-cutting machines B23Q; laser protective screens B23K26/706; protective shields for other welding methods F16P1/06
• CPC Class Codes: B23K 9/0953 using computing means
• CPC Class Codes: B23K 9/0956 using sensing means, e.g. optical
• CPC Class Codes: B23K 9/32 Accessories earthing connections H01R
• CPC Class Codes: G06T 2207/30108 Industrial image inspection
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G09B 19/24 Use of tools
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

A welding system includes one or more cameras and a controller coupled to the one or more cameras. The one or more cameras are configured to detect a plurality of sets of visual markers of a welding device, where each set is oriented in a respective marker direction. The controller is configured to determine one or more marker directions of one or more respective sets of visual markers based on a detected set of visual markers, to select one of the sets of visual markers as a tracked set of visual markers based at least in part on a determined marker direction of the tracked set of visual markers, to associate a rigid body model to the tracked set of visual markers, and to determine a position and an orientation of the welding device based on the associated rigid body model of the tracked set of visual markers.

Claims

1. A welding system comprising:

one or more cameras configured to detect a plurality of sets of visual markers of a welding device present within respective fields of view of the one or more cameras, wherein each set of visual markers corresponds to a different marker direction with respect to the welding device, wherein each set of visual markers comprises visual markers oriented in the corresponding marker direction; and

a controller coupled to the one or more cameras, wherein the controller is configured to;

determine one or more marker directions of one or more respective sets of visual markers of the plurality of sets of visual markers based at least in part on a detected set of visual markers of the plurality of sets of visual markers when the detected set of visual markers is within at least one field of view of the one or more cameras;

select one of the sets of visual markers of the plurality of sets of visual markers as a tracked set of visual markers based at least in part on a determined marker direction of the tracked set of visual markers;

select one of a plurality of rigid body models based on the selected set of visual markers, wherein each of the plurality of rigid body models corresponds to a respective set of the plurality of sets of visual markers; and

determine a position and an orientation of the welding device based on the selected rigid body model.

2. The welding system of claim 1, wherein the one or more cameras comprises a light source configured to emit light towards the welding device, and one or more of the visual markers is configured to reflect the emitted light towards lenses of the one or more cameras when the respective marker direction of the one or more visual markers is oriented towards the one or more cameras.

3. The welding system of claim 1, wherein the respective marker direction of the tracked set of visual markers is oriented toward at least one of the one or more cameras more than the marker directions of other sets of visual markers of the plurality of sets of visual markers.

4. The welding system of claim 1, wherein the controller selects the tracked set of visual markers from the plurality of sets of visual markers based at least in part on a continuous duration that the one or more cameras detects the tracked set of visual markers, wherein the continuous duration is greater than 200 milliseconds.

5. The welding system of claim 1, wherein the controller is configured to remain latched to the tracked set of visual markers when the determined marker direction of the tracked set of visual markers is within a latch angle threshold of a line of sight to the one or more cameras.

6. The welding system of claim 1, wherein each detected set of visual markers comprises three or more visual markers.

7. The welding system of claim 1, wherein the plurality of sets of visual markers comprise light emitting diodes (LEDs) configured to emit light in the respective marker directions.

8. The welding system of claim 7, wherein the controller is configured to turn on LEDs of the selected set of visual markers sets and to turn off LEDs of other sets of visual markers of the plurality of sets of visual markers.

9. The welding system of claim 1, wherein the controller is configured to determine welding parameters of the welding device based on the determined position and the determined orientation of the welding device.

10. The welding system of claim 9, wherein the controller is configured to record in a non-transitory, computer readable memory the determined welding parameters of the welding.

31. The welding system of claim 1, wherein each of the different marker directions corresponds to a different angular orientation of the corresponding set of markers with respect to the welding device.

11. A welding system comprising:

a welding torch, comprising;

a first set of at least three light emitting diodes (LEDs) oriented in a first marker direction with respect to the welding torch; and

a second set of at least three LEDs oriented in a second marker direction with respect to the welding torch;

one or more cameras configured to detect light emitted from the LEDs of the first set of LEDs or the second set of LEDs when the respective marker direction is oriented toward the one or more cameras; and

a controller coupled to the one or more cameras, wherein the controller is configured to;

detect a first rigid body model of the first set of LEDs when the first marker direction is oriented toward the one or more cameras;

detect a second rigid body model of the second set of LEDs when the second marker direction is oriented toward the one or more cameras;

determine a position and an orientation of the welding torch based on a detected rigid body model, wherein the detected rigid body model comprises the first rigid body model or the second rigid body model;

determine welding parameters of the welding torch based on the position and the orientation of the welding torch; and

record the welding parameters of the welding torch during a welding operation in a non-transitory, computer readable memory.

12. The welding system of claim 11, wherein the welding torch comprises a third set of at least three LEDs oriented in a third marker direction with respect to the welding torch, wherein the third marker direction is different than the first marker direction and the second marker direction, wherein the one or more cameras is configured to detect light emitted from the LEDs of the third set of LEDs when the third marker direction is oriented toward the one or more cameras, wherein the controller is configured to detect a third rigid body model of the third set of LEDs when the third marker direction is oriented toward the one or more cameras, the controller is configured to determine the position and the orientation of the welding torch based on the detected rigid body model, and the detected rigid body model comprises the first rigid body model, the second rigid body model, or the third rigid body model.

13. The welding system of claim 11, wherein the controller is configured to selectively control the first set of LEDs and the second set of LEDs during the welding operation to emit light from only one of the first set of LEDs and the second set of LEDs at a time.

14. The welding system of claim 11, wherein the controller is configured to determine the position and the orientation of the welding torch based on the determined first rigid body model when the first marker direction is oriented toward the one or more cameras more than the second marker direction, and the controller is configured to determine the position and the orientation of the welding torch based on the determined second rigid body model when the second marker direction is oriented toward the one or more cameras more than the first marker direction.

15. The welding system of claim 11, wherein the controller is configured to change the determination of the position and the orientation based on the first rigid body model to be based on the second rigid body model only when the first marker direction is oriented more than a latch threshold angle relative to a line of sight to the one or more cameras and the second marker direction is oriented less than the latch threshold angle relative to the line of sight to the one or more cameras, and the controller is configured to change the determination of the position and the orientation based on the second rigid body model to be based on the first rigid body model only when the second marker direction is oriented more than the latch threshold angle relative to the line of sight to the one or more cameras and the first marker direction is oriented less than the latch threshold angle relative to the line of sight to the one or more cameras.

16. The welding system of claim 11, wherein the controller is configured to control which of the first rigid body model and the second rigid body model is utilized to determine the position and the orientation of the welding torch using a hysteresis control based on the first marker direction, the second marker direction, a latch threshold angle, and the detected rigid body model.

17. The welding system of claim 11, wherein the controller is configured to determine the first marker direction based at least in part on the detected first rigid body model when the first marker direction is oriented toward the one or more cameras, and the controller is configured to determine the second marker direction relative to the first marker direction.

24. The method of claim 17, wherein the welding operation comprises a live arc welding operation.

18. A method comprising:

detecting, via one or more cameras, a first set of visual markers of a plurality of sets of visual markers coupled to a welding device present within respective fields of view of the one or more cameras, wherein each set of visual markers corresponds to a different marker direction with respect to the welding device, wherein each set of visual markers comprises visual markers oriented in the corresponding marker direction;

determining one or more marker directions of one or more respective sets of visual markers of the plurality of sets of visual markers based at least in part on the detected first set of visual markers of the plurality of sets of visual markers;

selecting one of the sets of visual markers of the plurality of sets of visual markers as a tracked set of visual markers based at least in part on a determined marker direction of the tracked set of visual markers;

selecting one of a plurality of rigid body models based on the selected set of visual markers, wherein each of the plurality of rigid body models corresponds to a respective set of the plurality of sets of visual markers;

determining a position and an orientation of the welding device based on the selected rigid body model;

determining welding parameters of the welding device during a welding operation based on the determined position and the determined orientation of the welding device; and

recording the welding parameters in a non-transitory, computer readable memory.

19. The method of claim 18, comprising:

detecting, via the one or more cameras, a second set of visual markers of the plurality of sets of visual markers coupled to the welding device; and

selecting the set of visual markers as the tracked set of visual markers based at least in part on a determined first marker direction of the first set of visual markers and a determined second direction of the second set of visual markers.

20. The method of claim 19, wherein selecting the set of visual markers as the tracked set of visual markers comprises utilizing a hysteresis control based on the determined first marker direction, the determined second marker direction, a latch threshold angle, and the associated rigid body model of the tracked set of visual markers.

21. The method of claim 18, wherein the visual markers of the first set of visual markers comprise light emitting diodes (LEDs).

22. The method of claim 18, comprising:

associating a first rigid body model to the first detected set of visual markers of the plurality of sets of visual markers; and

determining a first marker direction of the first set of visual markers relative to the first rigid body model of the first set of visual markers based at least in part on a relative position of two or more visual markers of the first set of visual markers.

23. The method of claim 18, comprising:

detecting, via the one or more cameras, two or more secondary visual markers distinct from the first set of visual markers;

associating a first rigid body model to the first detected set of visual markers of the plurality of sets of visual markers; and

determining a first marker direction of the first set of visual markers relative to the first rigid body model of the first set of visual markers based at least in part on a relative position of the two or more secondary visual markers.

25. A method comprising:

turning on a first set of light emitting diodes (LEDs) oriented in a first marker direction with respect to a welding device for a first detection interval, wherein the first set of LEDs is disposed on the welding device;

determining a first rigid body model of the first set of LEDs if one or more cameras detects the first set of LEDs within the first detection interval, wherein the first rigid body model is based on the detected arrangement of the first set of LEDs;

turning on a second set of LEDs oriented in a second marker direction with respect to a welding device for a second detection interval if the first set of LEDs is not detected by the one or more cameras within the first detection interval, the second marker direction having a different angular orientation with respect to the welding device than the first marker direction; and

determining a second rigid body model of the second set of LEDs if the one or more cameras detects the second set of LEDs within the second detection interval, wherein the second rigid body model is based on the detected arrangement of the second set of LEDs.

26. The method of claim 25, comprising controlling the first set of LEDs and the second set of LEDs so that only the first set of LEDs emits light during the first detection interval and only the second set of LEDs emits light during the second detection interval.

27. The method of claim 25, wherein the first detection interval and the second detection interval are less than approximately 500 ms.

28. The method of claim 25, comprising:

turning on a third set of LEDs oriented in a third marker direction for a third detection interval if the second set of LEDs is not detected by the one or more cameras within the second detection interval; and

determining a third rigid body model of the third set of LEDs if the one or more cameras detects the third set of LEDs within the third detection interval, wherein the third rigid body model is based on the detected arrangement of the third set of LEDs.

29. The method of claim 25, comprising repeating a cycle of turning on the first set of LEDs for the first detection interval and turning on the second set of LEDs for the second detection interval until the one or more cameras detects at least one of the first set of LEDs and the second set of LEDs.

30. The method of claim 25, wherein each of the first set of LEDs and the second set of LEDs comprises three or more LEDs, and the respective rigid body models are based at least in part on detection of at least three LEDs of each respective set of LEDs.