This article addresses the problem of distributed-parameter control for a c
lass of infinite-dimensional manufacturing processes with scanned thermal a
ctuation, such as scan welding. This new process is implemented on a roboti
c GTAW laboratory setup with infrared pyrometry, and simulated by a flexibl
e numerical computation program. An analytical linearized model, based on c
onvolution of Green's fields, is expressed in multivariable state-space for
m, with its time-variant parameters identified in-process. A robust control
ler design compensates for model uncertainty, and a sampled weighted attrac
tion method is introduced for heat source guidance based on real-time therm
al optimization of the heat input distribution. The distributed thermal reg
ulation strategy with infrared feedback is validated both computationally a
nd experimentally in scan welding tests.