When are dynamic and static feedback equivalent?

AbstractAn open question in Control Theory over commutative rings is: When does dynamic feedback equivalence imply (static) feedback equivalence? A second open problem is: Given a linear system Σ=(A,B), when does there exist a matrix F such that A+BF is invertible? In this paper we solve both questions, obtaining two characterizations of stable rings

Kalman reduced form and pole placement by state feedback for multi‐input linear systems over Hermite rings

[EN] A Kalman reduced form is obtained for linear systems over Hermite rings. This reduced form gives information of the set of assignable polynomials to a given linear system.S