Obtaining Routh-Pade approximants using the Luus-Jaakola algorithm

The Routh-Pade approximation problem relating to the construction of a stable reduced-order (rth-order) approximant G_r(s) for a given stable high-order (nth-order) transfer function G(s), so as to fully retain the first r time moments/Markov parameters of G(s) as well as to minimise the errors between a few subsequent time moments/Markov parameters of G(s) and those of G_r(s), is revisited. For the solution of this problem, a novel computer-aided method based on the well known Luus-Jaakola algorithm is proposed.