Reduced Order Model Based Flight Control System for a Flexible Aircraft

Abstract

The interaction between the flight control system and its structural modes becomes stronger if the frequency separation between rigid body mode and flexible modes of flexible aircraft are closer, and it introduces higher flexibility effects on aircraft dynamics. In such a case, the design of a flight control law is not valid based on the assumption that aircraft dynamics are rigid body models. Moreover, an integrated aircraft model having a rigid body and elastic body modes contain a large number of states. Therefore, we have designed an optimal flight control law from a reduced-order model and realized with a flexible aircraft represented by a full order model. For this, the simplified model of the flexible aircraft is derived using the Chidambara technique, and Luenberger observer is applied to estimating the elastic states of a simplified model from the aircraft measurements.