Flight Control Design Using the Quadratic Stabilizatiaaon Control Combined with Eigenstructure Assignmeaant

Main requirements for the flight control system are desirable response and robust stability. Eigenstructuare assignment (EA) is one of the approaches which achieave the desirable response. EA is based on the state feedback and some methods of designing the output feedback laws are proposed, but their output feedback laws have no guarantee for the robust stability. By the way, the quadratic stabilization (QS) has been often used to solve the robust control problem with structured uncertainty and disturbance attenuation. In this paper, we propose the 2-step approach which combines QS with EA. That is to say, at first step, a state feedback contraol law which achieves the desirable response is solved by EA. Next, a state estimator which has robust stabilitay against both structured uncertainty and unstructureda uncertainty is designed by QS with disturbance attenuation. Moreover, this new approach is applied to two examples of a longitudinal and a lateral-directionaaal flight control, as a result it is shown that the designead control laws give the good performance and robustness.