In this article we present a method for the on-line identification and
modeling of full profile disturbance models for sheet forming process
es. A particular principal components analysis technique called the Ka
rhunen-Loeve expansion is used to adaptively identify the significant
features of the profile. In addition, we show how the temporal modes o
f the reconstructed profile can be modeled using low-order linear auto
regressive (AR) processes. By simulation examples, the effect of the o
rder of the AR model is studied, as well as the window size of the dat
a used in the on-line application of the KL expansion, the effect of d
ata weighting, the importance of the correct selection of the number o
f modes, and the frequency of updating the parameters of the RR models
. Identified disturbance models can be easily incorporated into model-
predictive control algorithms.