Reduction of SISO H-infinity output feedback control problem

We consider the linear matrix inequality (LMI) problem of H∞ output feedback control for a generalized plant whose input, measured output, disturbance and controlled are scalar. provide an explicit form optimal value. This is unification some results in literature performance limitation analysis. To obtain value, we focus on non-uniqueness perpendicular matrices, which appear LMI problem. use null vectors invariant zeros associated with dynamical system expression matrices. enables us to reduce simplify Our approach uses well-known fundamental tools, e.g., Schur complement, Lyapunov equation, Sylvester completion. these techniques simplification Also, investigate structure dual feasible solutions size dual. reduction called facial convex optimization.