COMPUTATION OF COPRIME FACTORIZATIONS OF RATIONAL MATRICES

We propose numerically reliable state-space algorithms for computing s everal coprime factorizations of rational matrices: (1) factorizations with factors having poles in a given stability domain; (2) factorizat ions with proper stable factors; (3) factorizations with inner and J-i nner denominators. The new algorithms are based on a recursive general ized Schur algorithm for pole dislocation. They are generally applicab le whether the underlying descriptor state-space representation is min imal or not, and whether it is stabilizable/detectable or not. The pro posed algorithms are useful in solving various computational problems for both standard and descriptor system representations. (C) 1998 Else vier Science Inc.