Previous |  Up |  Next


scan welding; thermal control; distributed parameter; numerical method
This article addresses the problem of distributed-parameter control for a class of infinite-dimensional manufacturing processes with scanned thermal actuation, such as scan welding. This new process is implemented on a robotic GTAW laboratory setup with infrared pyrometry, and simulated by a flexible numerical computation program. An analytical linearized model, based on convolution of Green’s fields, is expressed in multivariable state-space form, with its time-variant parameters identified in-process. A robust controller design compensates for model uncertainty, and a sampled weighted attraction method is introduced for heat source guidance based on real-time thermal optimization of the heat input distribution. The distributed thermal regulation strategy with infrared feedback is validated both computationally and experimentally in scan welding tests.
[1] Astrom K. J., Wittenmark B.: Adaptive Control. Addison–Wesley, Reading 1995 MR 1351012
[2] Carslaw H. S., Jaeger J. C.: Conduction of Heat in Solids. Oxford Press, London 1959 MR 0022294 | Zbl 0972.80500
[3] Delfour M., Mitter S. K.: Controllability and observability for infinite dimensional systems. SIAM J. Control 10 (1972), 329–333 DOI 10.1137/0310024 | MR 0309588 | Zbl 0253.93007
[4] Doumanidis C. C.: Modeling and control of timeshared and scanned torch welding. ASME J. of Dynamic Systems, Measurement and Control 116 (1994), 3, 387–395 DOI 10.1115/1.2899233
[5] Doumanidis C. C., Hardt D. E.: Simultaneous in–process control of heat–affected zone and cooling rate ruring arc welding. Welding Journal 69 (1990), 5, 186s–196s
[6] Duff I. S., Stewart D. J.: Sparse Matrix Proceedings. SIAM, Philadephia, 1979 MR 0566373 | Zbl 0401.00013
[7] Hale M. B., Hardt D. E.: Multi–output process dynamics in GMAW: limits to control. Internat. Trends in Welding Science and Technology, ASM Gatlinburg TN, (1992), 1015–1020
[8] Rosenbluth N. Metropolis, A. M., Teller A. E.: J. Chem. Phys. (1953), 1087–1092
[9] Miyachi H.: $n$–Process Control of Root-Gap Changes During Butt Welding. Dept. of Mechanical Engineering, MIT, Cambridge, MA 1989
[10] Murio D. A.: The Molification Method and the Numerical Solution of Ill–Posed Problems. Wiley, New York 1993 MR 1227986
[11] Ray W. H., Lainiotis D. G.: DPS–Identification, Estimation and Control. M. Dekker, New York 1978 MR 0527208
[12] Schmitendorf W. E., Barmish B. R.: Guaranteed asymptotic stability for systems with constant disturbances. In: Proceedings of ACC, Boston 1985
Partner of
EuDML logo