Cc. Doumanidis et N. Fourligkas, Temperature distribution control in scanned thermal processing of thin circular parts, IEEE CON SY, 9(5), 2001, pp. 708-717
Scan thermal processing is enabled by guidance of the heat source trajector
y during fabrication. For thin, cylindrically symmetric parts, this is perf
ormed by their rapid revolution under a radially or axially translated torc
h, with its power modulated so as to implement a specified thermal distribu
tion as it sweeps the product surface, and thus to generate desirable mater
ial features. A new analytical description of the thermal field in thin dis
k-shaped parts, based on superposition of Green's functions, was developed
for off-line analysis. A multivariable linearized model with least-squares
identification of its varying parameters was also derived for real-time emi
ssivity compensation and prediction of delayed temperature data. This model
is embedded to a thermal distribution control scheme, driving the scanned
torch motion and power by a new real-time simulated annealing optimization
strategy, using temperature feedback from randomly sampled surface location
s by an infrared pyrometer. The thermal regulator is validated computationa
lly and experimentally.