Mixed H2/H-infinity optimal control for an elastic aircraft

Abstract

A mixed //2/floo optimal control design and its application to a flight control problem of B-l aircraft is studied. The mixed #2/ 00 optimal control design is one of finding an internally stabilizing controller that minimizes the //2/#oo performance index subject to an inequality constraint on H^ norm. The application is a linear model of longitudinal motion of B-l aircraft. A standard eigenvalue problem that involves linear matrix inequalities is formulated, and efficient interior point algorithms are used to solve this problem numerically. Results show that this mixed //2/#oo optimal design leads the designer into a tradeoff between HI and HQQ objectives. Through this method, a designer can determine the controllers that result in the desired closed-loop noise rejection properties and stability robustness.