Systems and methods to control welding wire tension

Patent metadata

Field	Value
Publication number	US-12290887-B2
Application number	US-202117246142-A
Country	US
Kind code	B2
Filing date	Apr 30, 2021
Priority date	Apr 30, 2021
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

An example welding wire feeder includes: a push motor configured to feed welding wire from a wire source; a first sensor configured to provide push motor velocity feedback; and control circuitry configured to control the push motor and a pull motor of a welding torch coupled to the welding wire feeder by: controlling a push motor velocity of the push motor and a pull motor velocity of the pull motor based on a target wire feed speed; and compensating each of the push motor velocity of the push motor and the pull motor velocity of the pull motor based on the push motor velocity feedback and based on pull motor velocity feedback, wherein the push motor velocity and the pull motor velocity are based on a target wire tension.

First claim

What is claimed is:

1. A welding wire feeder, comprising:
a push motor configured to feed welding wire from a wire source;
a first sensor configured to provide push motor velocity feedback; and
control circuitry configured to control the push motor and a pull motor of a welding torch coupled to the welding wire feeder by: controlling a push motor velocity of the push motor and a pull motor velocity of the pull motor based on a target wire feed speed;
determine an estimated friction force in response to the push motor velocity and the pull motor velocity reaching a threshold velocity based on a velocity command;
estimating a wire slip velocity based on a push motor force and a pull motor force;
estimating a wire tension in the welding wire based on the wire slip velocity, the push motor velocity feedback, and the pull motor velocity feedback, based on reducing a difference in the push motor force and the pull motor force by the estimated friction force; and
compensating each of the push motor velocity of the push motor and the pull motor velocity of the pull motor based on the push motor velocity feedback, pull motor velocity feedback, the estimated wire tension, and the estimated wire slip velocity, wherein the push motor velocity and the pull motor velocity are based on a target wire tension.

2. The welding wire feeder as defined in claim 1 , wherein the control circuitry is configured to generate a velocity command based on the target wire feed speed and the target wire tension, and the control circuitry is configured to control the push motor velocity of the push motor and the pull motor velocity of the pull motor based on the velocity command.

3. The welding wire feeder as defined in claim 1 , wherein the control circuitry is configured to estimate the wire tension based on adding the estimated wire slip velocity to a difference between the push motor velocity feedback and the pull motor velocity feedback.

4. The welding wire feeder as defined in claim 1 , wherein the first sensor comprises an encoder coupled to the push motor to measure at least one of an angular position or an angular velocity of the push motor.

5. The welding wire feeder as defined in claim 1 , wherein the control circuitry is configured to, at a beginning of a welding operation, control the pull motor and the push motor to apply forces to the welding wire in opposing directions to establish a reference wire tension based on the target wire tension.

6. The welding wire feeder as defined in claim 1 , wherein the control circuitry is configured to determine the pull motor velocity feedback based on receiving at least one of a pull motor angular velocity or a pull motor angular position from a pull motor encoder of the welding torch coupled to the welding wire feeder.

7. The welding wire feeder as defined in claim 1 , wherein the control circuitry is configured to set the target wire tension based on a type of the welding wire.

8. The welding wire feeder as defined in claim 1 , wherein controlling the push motor velocity of the push motor comprises generating a push motor force command, and controlling the pull motor velocity of the pull motor comprises generating a pull motor force command.

9. The welding wire feeder as defined in claim 8 , wherein the control circuitry is configured to control the push motor velocity of the push motor by setting the push motor force command using an integrator based on a velocity command and the push motor velocity feedback.

10. The welding wire feeder as defined in claim 8 , wherein the control circuitry is configured to control the pull motor velocity of the pull motor by setting a pull motor force using an integrator based on a velocity command and the pull motor velocity feedback.

11. A method to control welding wire tension, the method comprising:
controlling, via control circuitry, a push motor velocity of a push motor of a welding wire feeder based on a target wire feed speed;
controlling, via the control circuitry, a pull motor velocity of a pull motor of a welding torch coupled to the welding wire feeder based on the target wire feed speed;
determining, via the control circuitry, an estimated friction force in response to the push motor velocity and the pull motor velocity reaching a threshold velocity based on a velocity command;
estimating, via the control circuitry, a wire slip velocity based on a push motor force and a pull motor force;
estimating, via the control circuitry, a wire tension in the welding wire based on the wire slip velocity, the push motor velocity feedback, and the pull motor velocity feedback, based on reducing a difference in the push motor force and the pull motor force by the estimated friction force; and
compensating, via the control circuitry, each of the push motor velocity of the push motor and the pull motor velocity of the pull motor based on push motor velocity feedback, pull motor velocity feedback, the estimated wire tension, and the estimated wire slip velocity, wherein the push motor velocity and the pull motor velocity are based on a target wire tension.

12. The method as defined in claim 11 , wherein the controlling of the push motor velocity of the push motor comprises generating a push motor force command, and the controlling of the pull motor velocity of the pull motor comprises generating a pull motor force command.

13. The method as defined in claim 11 , wherein the estimating of the wire tension is based on adding the estimated wire slip velocity to a difference between the push motor velocity feedback and the pull motor velocity feedback.

14. The method as defined in claim 11 , further comprising measuring at least one of an angular position or an angular velocity of the push motor with an encoder, and determining the push motor velocity feedback based on the angular position or the angular velocity.

15. The method as defined in claim 11 , further comprising, at a beginning of a welding operation, controlling the pull motor and the push motor to apply forces to the welding wire in opposing directions to establish a reference wire tension based on the target wire tension.

16. The method as defined in claim 11 , further comprising setting the target wire tension based on a type of the welding wire.

Assignees

• Illinois Tool Works

Inventors

• Petit Marc S
• Batzler Todd G
• Romenesko Charles J

Classifications

• B23K9/125

  Feeding of electrodes (for stabilising arc B23K9/073) · CPC title

• B65H59/384

  using electronic means · CPC title

• B65H2701/36

  Wires · CPC title

• B65H59/388

  Regulating forwarding speed · CPC title

• B23K9/1336 Primary

  Driving means · CPC title