Robot control system and method for TIG welding

• US 5,770,834 A
• Filed: 08/14/1996
• Issued: 06/23/1998
• Est. Priority Date: 08/14/1996
• Status: Expired due to Fees

• Current Assignee: ABB Flexible Automation, Inc. (ABB Limited)
• Original Assignee: ABB Flexible Automation, Inc. (ABB Limited)
• Inventors: Carey, Steven G., Davis, Patrick S.
• Primary Examiner(s): Shaw, Clifford C.
• Application Number:
  US08/696,686
• Time in Patent Office: 678 Days
• Field of Search: 219/130.5, 219/60 A, 219/124.03, 219/125.1, 219/130.31, 219/130.32, 219/130.33, 219/137.71, 219/137 PS, 219/75, 219/130.51
• US Class Current: 219/130.5
• CPC Class Codes: B23K 9/0953 using computing means

Abstract

A robot control system that includes a controller that is capable of controlling the current supplied to a current-controlled tool mounted on the robot. The controller is capable of accepting operator inputs and the robot is coupled in data communication to the controller. A tool which is controlled in at least one manner by electric current is mounted on the arm of the robot. The controller is coupled in data communication to a current source and is programmed to control the current supplied to the tool. The controller is also capable of receiving inputs from an operator and is capable of ramping the current supplied to the tool from an initial current level to an operator selected current level over an operator defined and inputted selected time. The controller can also ramp the current supplied to the tool from the selected current level to a third current level over a second operator selected and inputted time period.

Claims

1. A robotic system for use by an operator, the system comprising:

a controller capable of accepting operator inputs and having means for storing a program and a program, the program containing a programmed path with a number of predetermined positions;

a robot coupled in data communication to the controller, the robot including a robot arm and a current-controlled tool mounted thereon, the robot for moving the current controlled tool along the programmed path; and

an electric current source coupled in data communication to the controller and capable of supplying an electric current to the current-controlled tool;

the controller including

means for controlling the electric current source, the means capable of ramping current supplied to the current-controlled tool in a step-wise fashion from an initial current level to an operator selected current level over an operator selected time;

means for controlling the speed of the current-controlled tool as it moves from one position to another along the programmed path;

means for controlling the total time the current-controlled tool is in motion while traveling along the programmed path; and

means for controlling the positional accuracy of the current-controlled tool with respect to the desired positions of the programmed path.

2. A robotic system as claimed in claim 1, wherein the means for controlling the electric current source is capable of causing the current supplied to the current-controlled tool to ramp down from the selected current level to a third current level over a second operator selected time period in a step-wise fashion.

3. A robotic system as claimed in claim 1, wherein the current-controlled tool is a welding torch.

4. A robotic system as claimed in claim 3, wherein the means for controlling the current source is capable of pulsing the amplitude of the current supplied to the current controlled tool.

5. A robotic control system as claimed in claim 3, wherein the welding torch is a TIG welding torch, the robot control system further comprising

a welding feed reel including a filler wire;

and

means for controlling the speed of feeding the filler wire to the TIG welding torch.

6. A welding system for use by an operator, the welding system comprising:

a controller capable of accepting operator inputs and having means for storing a program and a program, the program containing a programmed path with a number of predetermined positions;

a robot coupled in data communication to the controller, the robot including a robot arm and a welding torch mounted thereto and for moving the welding torch along the programmed path, the welding torch including an electrode; and

an electric current source coupled in data communication to the controller and capable of supplying an electric current to the electrode;

the controller including

means for controlling the electric current source, said means capable of ramping up the current supplied to the electrode from an initial current level to an operator selected current level over an operator selected time, said operator selected time input to said controller by the operator, and capable of ramping the current supplied to the electrode down from the selected current level to a third current level over a second operator selected time period, said second operator selected time input to said controller by the operator;

means for controlling the speed of the welding torch as it moves from one position to another along the programmed path;

means for controlling the total time the welding torch is in motion while traveling along the programmed path; and

means for controlling the positional accuracy of the welding torch with respect to the desired positions of the programmed path.

7. A welding system as claimed in claim 6, wherein the means for controlling the current source is capable of pulsing the current supplied to the welding torch.

8. A welding system as claimed in claim 7, wherein the welding torch is a TIG welding torch, the control system further comprising

a welding feed reel including a filler wire;

and

a means for controlling the speed of feeding the filler wire to the TIG welding torch.

9. A robotic system for use by an operator, the system comprising:

a controller capable of accepting operator inputs and having means for storing a program and a program, the program containing a programmed path with a number of predetermined positions;

a robot coupled in data communication to the controller, the robot including a robot arm and a current-controlled tool mounted thereon and for moving the current-controlled tool along the programmed path; and

an electric current source coupled in data communication to the controller and capable of supplying an electric current to the current-controlled tool;

the controller including

means for controlling the electric current source, the means capable of ramping up the current supplied to the current-controlled tool in a series of discrete steps, each step having an equal time, the current being ramped up between an initial current level to an operator selected current level over an operator selected time;

means for controlling the speed of the current-controlled tool as it moves from one position to another along the programmed path;

means for controlling the total time the current-controlled tool is in motion while traveling along the programmed path; and

means for controlling the positional accuracy of the current-controlled tool with respect to the desired positions of the programmed path.

10. A robotic system as claimed in claim 9, wherein the means for controlling the electric current source is capable of causing the current supplied to the current-controlled tool to ramp down in a series of discrete steps, each step having an equal time, between the selected current level to a third current level over a second operator selected time period.

11. A robotic system as claimed in claim 10, wherein the means for controlling the current source is capable of pulsing the amplitude of the current supplied to the current controlled tool.

12. A robot control system for use by an operator and to control a robot with an arm, the system comprising:

a controller capable of accepting operator inputs;

a welding tool capable of being mounted on the robot arm and coupled in data communication with the controller;

an electric current source coupled in data communication to the controller and capable of supplying an electric current to the welding tool;

means for controlling the electric current source, the means capable of ramping current supplied to the welding tool in a step-wise fashion from an initial current level to an operator selected current level over an operator selected time and pulsing the amplitude of the current supplied to the welding tool; and

means for adjusting the feed rate at which a filler wire is supplied to the welding tool so that the feed rate of the filler wire corresponds to the amplitude of the pulsed current supplied to the welding tool.

13. A robot control system for use by an operator and to control a robot with an arm, the system comprising:

a controller for accepting operator inputs and having a means for storing a programmed path and a programmed path;

the programmed path having a number of predetermined positions;

a welding tool capable of being mounted on the arm and coupled in data communication to the controller;

an electric current source coupled in data communication to the controller and for supplying an electric current to the welding tool; and

means for controlling the electric current source, the means capable of ramping current supplied to the current-controlled tool in a step-wise fashion from an initial current level to a first operator selected current level over an operator selected time and ramping the current supplied to the current-controlled tool in a step-wise fashion down from the first operator selected current level to a second current level over a second operator selected time;

means for controlling the speed of the welding tool as it moves from one position to another along the programmed path;

means for controlling the total time the welding tool is in motion while traveling along the programmed path;

means for controlling the positional accuracy of the welding tool with respect to the desired positions recorded in the programmed path; and

means for controlling the weave pattern of the welding tool while the welding tool is welding.