H-INFINITY CONTROL FOR A SINGULARLY PERTURBED AIRCRAFT MODEL

State space solutions for Hinfinity control are formulated for composi te state feedback control of singularly perturbed systems. Scaled freq uency domain realizations of dynamic systems are developed and used to generate Hinfinity solutions that approach the H-2 solution as an Hin finity-norm design parameter is allowed to approach infinity. The real izations also account for non-orthogonal cost function terms that occu r naturally in the slow subsystem design for singularly perturbed syst ems. Traditional H-2 results are also provided. The formulation is app lied to compute reduced, composite and full-order controller gains for the longitudinal dynamics of an F-8 aircraft.