On the computation of a nonlinearity measure using functional expansions

Nonlinearity measures quantify the degree of nonlinearity in dynamic system s. In this work, we present a novel approach to the computation of these me asures by functional expansions. Rather than calculating an exact nonlinear ity measure which is often computationally intensive, functional expansion (FEx) models are used to derive approximate lower and upper bounds on the m easure. The resulting bounds are algebraic in nature and provide insight in to the effect of process parameters on the nonlinearity measure. These conc epts an illustrated by a benchmark CSTR problem. (C) 2000 Elsevier Science Ltd. All rights reserved.