A general approach to the eigenstructure assignment for reachability and stabilizability subspaces

Abstract

This paper is concerned with the problem of determining basis matrices for the supremal output-nulling, reachability and stabilizability subspaces, and the simultaneous computation of the associated friends that place the assignable closed-loop eigenvalues at desired locations. Our aim is to show that the Moore–Laub algorithm in Moore and Laub (1978) for the computation of these subspaces was stated under unnecessary restrictive assumptions. We prove the same result under virtually no system-theoretic hypotheses. This provides a theoretical foundation to a range of recent geometric techniques that are more efficient and robust, and as general as the standard ones based on the computation of sequences of subspaces.