q Suppose (A,B2) is stabilizable and (C2,A) is detectable.
qYoula parameterization: all controllers K that internally stabilize G.
qSuppose GÎ RH¥ . Then K=Q(I+G22Q)-1, Q Î RH¥ and I+G22Q(¥ ) nonsingular.
qProof: K stabilizes a stable
plant G22 iff K(I-G22K)-1 is stable. So the conclusion follows by
letting Q
= K(I-G22K)-1.