'Institute of Electrical and Electronics Engineers (IEEE)'
Abstract
Rational functions of several noncommuting indeterminates arise naturally in robust control when studying systems with structured uncertainty. Linear fractional transformations (LFTs) provide a convenient way of obtaining realizations of such systems and a complete realization theory of LFTs is emerging. This paper establishes connections between a minimal LFT realization and minimal realizations of a formal power series, which have been studied extensively in a variety of disciplines. The result is a fairly complete generalization of standard minimal realization theory for linear systems to the formal power series and LFT setting
