Definition (Equivalent realization)
We say that two Realizations (A,B,C,D) and (A~,B~,C~,D~) of a given Weighting Pattern are equivalent if ∀u∈C([t0,∞],Rm) and ∀t≥t0, we have t0∫tCeA(t−τ)Bu(τ)dτ+Du(t)=t0∫tC~eA~(t−τ)B~u(τ)dτ+D~u(t)
Lemma (Alternative characterization of equivalence)
Two Realizations (A,B,C,D) and (A~,B~,C~,D~) of a given Weighting Pattern are equivalent if and only if ∀t≥0:CeAtB=C~eA~tB~⟺∀k∈N:CAkB=C~A~kB~and D=D~
Lemma (Realizations are Equivalent if Laplace Transform is Equivalent)
Two Realizations (A,B,C,D) and (A~,B~,C~,D~) are equivalent if and only if (ACBD)(s)=(A~C~B~D~)(s)∀s∈C where the Transfer Functions are defined.