Control of dynamic keyhole welding process

Y. M. Zhang, Y. C. Liu

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


Weld joint penetration control is a basic research topic in the welding research community. The authors propose using an innovative plasma arc welding process referred to as the quasi-keyhole process to achieve less application-dependent weld joint penetration sensing and control. To control the quasi-keyhole process, the peak current and keyhole sustaining current are selected as the control variables to maintain the keyhole establishment and sustaining periods at desired values. The dynamic quasi-keyhole process is approximated by a linear model with interval parameters. A control algorithm has been developed for the multivariable interval quasi-keyhole process based on a predictive control algorithm for interval SISO models. Experiments have been conducted to test the effectiveness of the control system developed.

Original languageEnglish
Pages (from-to)876-884
Number of pages9
Issue number5
StatePublished - May 2007

Bibliographical note

Funding Information:
This research is funded by the National Science Foundation under Grant DMI-0114982 and the University of Kentucky Center for Manufacturing. YuMing Zhang has been with the University of Kentucky since 1991 where he is currently a Professor and the James R. Boyd Professor of Electrical Engineering. He was a faculty member from 1984 to 1991 in the State Key Laboratory for Advanced Welding Production Technology at the Harbin Institute of Technology, China where he received his Ph.D. degree in Mechanical Engineering/Welding Major, and M.S. and B.S. degrees in Electrical Engineering/Control Major. Dr. Zhang is a senior member of the IEEE and the SME, and a member of the AWS and the ASME. He received The Donald Julius Groen Prize from The Institution of Mechanical Engineers, United Kingdom; The A. F. Davis Silver Medal award from the American Welding Society; the Adams Memorial Membership Award from the American Welding Society; and the 15th IFAC Triennial World Congress Best Poster Paper Prize and Application Paper Honorable Mention from the International Federation of Automatic Control. YuChi Liu is currently a Control Engineer at Magnatech Limited Partnership in East Granby, Connecticut, USA. He received his Ph.D. degree and an M.S. degree in Electrical Engineering from the University of Kentucky, Lexington, Kentucky, USA; an M.S. degree in Welding Major from Harbin Institute of Technology, Harbin, China; and his B.S. degree in Welding Major from Wuhan University of Hydraulic and Electrical Engineering, Wuhan, China. Dr. Liu is an AWS member. Dr. Liu received the 15th IFAC Triennial World Congress Best Poster Paper Prize and Application Paper Honorable Mention from the International Federation of Automatic Control.


  • GTAW
  • Interval model
  • Intervals
  • Keyhole
  • Manufacturing
  • PAW
  • Penetration
  • Predictive control
  • Robust control
  • Welding

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering


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