Patent · US Expired

Apparatus and methods for controlling a welding process

US4595820A · kind A · utility

118Cited by
15References
15Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 23, 1984
Grant dateJun 17, 1986
Priority date
Expiry dateApr 23, 2004

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB23K9/0956
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

Video data generated at a high rate by a camera observing a welding operation is selectively stored in a video-computer interface to permit later computer analysis of the data. Special multiple memory techniques can be employed when the rate of which the data is generated is too fast for storage in a single memory in the interface. The width of the weld pool is detected by finding local minima of light intensity associated with these edges. The mass of the weld pool and the weld penetration can be measured and controlled by causing oscillations in the weld pool and measuring the natural frequency of such oscillations. The weld line can be tracked either by bouncing a beam of light off the welding electrode so as to form an illuminated area and detecting the resulting irregularity where the illuminated area crosses the weld line, or by detecting the deformation in the surface of the weld pool as the pool flows into the gap between the metal portions being joined. Prior to welding, the weld line can be detected by establishing a low power welding arc insufficient to create a molten weld pool but generating enough light to produce an irregularity in the reflected light at the location…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.