Waveform compensation systems and methods for secondary weld component response

Patent metadata

Field	Value
Publication number	US-9387550-B2
Application number	US-201213619499-A
Country	US
Kind code	B2
Filing date	Sep 14, 2012
Priority date	Sep 14, 2012
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A method includes receiving data corresponding to a weld waveform that is generated during a welding operation and determining, based on the received data corresponding to the weld waveform, an overshoot voltage for the welding operation that exceeds an expected voltage level. The method further includes receiving data corresponding to a measured stud voltage and calculating, based on the overshoot voltage and the measured stud voltage, a stud voltage for the welding operation. The method also includes controlling at least one parameter of the welding operation based on the stud voltage for the welding operation.

First claim

The invention claimed is:

1. A method, comprising:
accessing, via a processor, data corresponding to a measured stud voltage and a current of a weld waveform that is generated during a welding operation;
determining, via the processor, an overshoot voltage for the welding operation that exceeds an expected voltage level, wherein the overshoot voltage is determined based on a ramp rate of the current of the weld waveform;
calculating, via the processor, based on the overshoot voltage and the measured stud voltage, a compensated stud voltage for the welding operation; and
controlling, via the processor, welding power configured to compensate for effects of inductance based on the compensated stud voltage for the welding operation, wherein at least part of the compensation for inductance is performed without reference to a voltage measured by a voltage sensing lead.

2. The method of claim 1 , wherein calculating the compensated stud voltage for the welding operation comprises subtracting, via the processor, the overshoot voltage for the welding operation from the measured stud voltage.

3. The method of claim 1 , wherein determining the overshoot voltage for the welding operation comprises determining, via the processor, a quantity corresponding to an instantaneous ramp rate divided by an average ramp rate and multiplying the determined quantity by an overshoot average ramp voltage.

4. The method of claim 1 , comprising determining, via the processor, a compensated weld waveform for the weld operation based on the calculated compensated stud voltage for the welding operation.

5. The method of claim 4 , comprising displaying the weld waveform and the compensated weld waveform on a user interface of a welding power supply.

6. A controller for a welding system, configured to:
access data corresponding to a measured stud voltage and a current of a weld waveform generated during a welding operation;
determine an amount of voltage overshoot in the weld waveform for the welding operation that exceeds an expected voltage level for the welding operation, wherein the amount of voltage overshoot is determined based on a ramp rate of the current of the weld waveform;
compute a compensated stud voltage for the welding operation based on the amount of voltage overshoot and the measured stud voltage; and
output a weld command for the welding operation corresponding to an expected weld command adjusted to control welding power configured to compensate for effects of inductance based on the compensated stud voltage for the welding operation, wherein at least part of the compensation for the inductance is performed without reference to a voltage measured by a voltage sensing lead.

7. The controller of claim 6 , wherein the controller is configured to compute the compensated stud voltage by subtracting the voltage overshoot for the welding operation from the measured stud voltage.

8. The controller of claim 6 , further configured to receive one or more inputs from a user regarding at least one of a negative weld cable length, a negative weld cable size, a positive weld cable length, a positive weld cable size, or a combination thereof.

9. The controller of claim 8 , further configured to utilize at least one of the negative weld cable length, the negative weld cable size, the positive weld cable length, and the positive weld cable size to determine the weld command for the welding operation.

10. The controller of claim 6 , wherein the weld command for the welding operation comprises at least one of a voltage command and a current command.

11. The controller of claim 6 , wherein the controller is configured to determine the amount of overshoot voltage by determining a quantity corresponding to an instantaneous ramp rate divided by an average ramp rate and multiplying the determined quantity by an overshoot average ramp voltage.

12. A welding system, comprising:
a welding power supply configured to generate a weld waveform during a welding operation;
a welding torch coupled to the welding power supply via a torch cable;
a fixture configured to secure a workpiece in a welding location;
a ground cable coupled to the welding power supply and at least one of the fixture and the workpiece; and
a controller configured to monitor a measured stud voltage and a current of the weld waveform, to determine an overshoot voltage for the welding operation, to determine a compensated stud voltage based on the measured stud voltage and the overshoot voltage, and to utilize the compensated stud voltage to control welding power configured to compensate for effects of inductance of the welding operation, wherein the overshoot voltage is determined based on a ramp rate of the current of the weld waveform, and wherein the compensated stud voltage corresponds to a voltage level at the welding location reduced from the measured stud voltage to compensate for at least part of the inductance without reference to a voltage measured by a voltage sensing lead.

13. The system of claim 12 , wherein the controller is configured to compute the compensated stud voltage by subtracting the overshoot voltage from the measured stud voltage.

14. The system of claim 12 , wherein the controller is configured to determine the overshoot voltage by determining a quantity corresponding to an instantaneous ramp rate divided by an average ramp rate and multiplying the determined quantity by an overshoot average ramp voltage.

15. The system of claim 12 , wherein the welding power supply comprises a constant current welding power supply.

16. The system of claim 12 , wherein the welding power supply comprises a metal inert gas (MIG) power supply, a tungsten inert gas (TIG) power supply, or a stick power supply.

17. The method of claim 1 , wherein the ramp rate comprises an average ramp rate.

18. The controller of claim 6 , wherein the ramp rate comprises an average ramp rate.

19. The system of claim 12 , wherein the ramp rate comprises an average ramp rate.

Assignees

• Davidson Robert R
• Bunker Thomas A
• Schuh Richard
• Illinois Tool Works

Inventors

• Davidson Robert R
• Bunker Thomas A
• Schuh Richard

Classifications

• B23K9/0953 Primary

  using computing means · CPC title

• H02M3/157

  with digital control · CPC title

• B23K9/133

  Means for feeding electrodes, e.g. drums, rolls, motors · CPC title

• B23K9/1043

  characterised by the electric circuit (B23K9/1012 takes precedence) · CPC title

• B23K9/0956 Primary

  using sensing means, e.g. optical · CPC title