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US 9,539,662 B2Granted
Extraction of arc length from voltage and current feedback
AssigneeIllinois Tool Works Inc.
InventorRichard Martin Hutchison
Life of this patent
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Abstract
A method of controlling a welding system includes controlling a weld current supplied to an electrode at a current ramp rate and determining an arc length based at least in part on the controlled weld current and a changing arc voltage. The arc length includes a distance between the electrode and a workpiece, and the arc voltage includes a voltage between the electrode and the workpiece.
Claims19
Method of controlling a welding system comprising:
- controlling, via control circuitry of the welding system, a weld current supplied to an electrode at a current ramp rate over a time segment;
- and
- determining, via the control circuitry, an arc length based at least in part on the controlled weld current and a changing arc voltage during the time segment, wherein the arc length comprises a distance between the electrode and a workpiece, the changing arc voltage comprises a voltage between the electrode and the workpiece, and the arc length is determined without altering the weld current for measurement purposes.
A welding system comprising:
- power conversion circuitry configured to provide a pulse welding waveform to a torch, wherein the pulse welding waveform comprises a peak portion, and the peak portion comprises a ramp up portion or a ramp down portion;
- one or more sensors configured to sense a weld voltage of the pulse welding waveform and a weld current of the pulse welding waveform applied to an electrode within the torch;
- and
- processing circuitry coupled to the one or more sensors, wherein the processing circuitry is configured to determine an arc length based at least in part on changes to the weld current and changes to the weld voltage during the ramp up portion or the ramp down portion, wherein the arc length comprises a distance between the electrode and a workpiece, and the processing circuitry is configured to determine the arc length based at least in part on upward slopes of the weld current and the weld voltage during the ramp up portion, downward slopes of the weld current and the weld voltage during the ramp down portion, an upward regression model of the weld current and the weld voltage during the ramp up portion, or a downward regression model of the weld current and the weld voltage during the ramp down portion.
1 more element
Method of controlling a welding system comprising:
- sensing, via one or more sensors, a changing weld current and a changing voltage of a pulse welding waveform, wherein the changing weld current and the changing voltage occur during a ramp up portion or a ramp down portion of a pulse of the pulse welding waveform;
- determining, via control circuitry coupled to the one or more sensors, a resistance of an electrode based at least in part on upward slopes of the changing weld current and the changing voltage during the ramp up portion, downward slopes of the changing weld current and the changing voltage during the ramp down portion, an upward regression model of the changing weld current and the changing voltage during the ramp up portion, or a downward regression model of the changing weld current and the changing voltage during the ramp down portion;
- determining, via the control circuitry, an arc voltage based at least in part on a weld voltage, the resistance, and a fall voltage;
- and
- controlling, via the control circuitry, an arc length during the pulse welding waveform based at least in part on a functional relationship between the arc length and the arc voltage, wherein the arc length comprises a distance between the electrode and a workpiece.
2 more elements
Dependencies are inferred from the claim text.