Method for enhanced control of welding processes

Patent · Tue Jul 04 04:00:00 EDT 2000

OSTI ID:20080537

Sheaffer, D A; Renzi, R F; Tung, D M; Schroder, K

Method and system for producing high quality welds in welding processes, in general, and gas tungsten arc (GTA) welding, in particular by controlling weld penetration are disclosed. Light emitted from a weld pool is collected from the backside of a workpiece by optical means during welding and transmitted to a digital video camera for further processing, after the emitted light is first passed through a short wavelength pass filter to remove infrared radiation. By filtering out the infrared component of the light emitted from the backside weld pool image, the present invention provides for the accurate determination of the weld pool boundary. Data from the digital camera is fed to an imaging board which focuses on a 100 x 100 pixel portion of the image. The board performs a thresholding operation and provides this information to a digital signal processor to compute the backside weld pool dimensions and area. This information is used by a control system, in a dynamic feedback mode, to automatically adjust appropriate parameters of a welding system, such as the welding current, to control weld penetration and thus, create a uniform weld bead and high quality weld.

• Sponsoring Organization: US Department of Energy
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 20080537
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
36 MATERIALS SCIENCE
FEEDBACK
GAS TUNGSTEN-ARC WELDING
ON-LINE CONTROL SYSTEMS
ON-LINE MEASUREMENT SYSTEMS
OPTICAL SYSTEMS
PROCESS CONTROL
WELDING MACHINES