MIXED H-2 H-INFINITY OPTIMAL-CONTROL FOR AN ELASTIC AIRCRAFT/

A mixed H-2/H-infinity, optimal control design and its application to a flight control problem of B-1 aircraft is studied. The mixed H-2/H-i nfinity, optimal control design is one of finding an internally stabil izing controller that minimizes the H-2/H-infinity performance index s ubject to an inequality constraint on H-infinity norm. The application is a linear model of longitudinal motion of B-1 aircraft. A standard eigenvalue problem that involves linear matrix inequalities is formula ted, and efficient interior point algorithms are used to solve this pr oblem numerically. Results show that this mixed H-2/H-infinity optimal design leads the designer; into a tradeoff between H-2 and H-infinity objectives. Through this method, a designer can determine the control lers that result in the desired closed-loop noise rejection properties and stability robustness.