DEFINITION OF THE FLEXIBLE AIRCRAFT LONGITUDINAL MODEL FOR A PRELIMINARY CONTROL DESIGN

Developing control system of high aspect ratio aircraft can be challenging due to flexibility involved in the control loop design. A model based approach can be straightforward to tune the control system parameters and, to this aim, a reliable aircraft flexible model is necessary. This paper aims to present the approach followed to design the longitudinal control strategy considering the aircraft simulator in the loop. The elastic modes are calculated from the lumped mass geometrical model and an aerodynamic properties from a reference aircraft. The approach and the model validation have been done in partnership with Leonardo Aircraft, as a thesis topic. Beginning with verification of the trim conditions, the flexible dynamic modes are compared to the rigid ones in order to highlight the relevant changes in the aircraft modes. A preliminary design of the longitudinal control strategy is herein proposed to achieve the dynamic response objectives.