Feedback invariants of restrictions and quotients: series connected systems Original Research Article

The problem of the feedback invariants of parallel and series connected systems is considered. It is shown that this problem is closely related to the characterization of the feedback invariants of a system with prescribed restriction and/or quotient to a controlled invariant subspace. Namely, under the assumption of complete controllability of the quotient, the relationship between the feedback invariants of (A,B) and those of its restriction and quotient is investigated.