Non-linear control of the longitudinal rotational dynamics of a flexible aircraft

This paper studies the longitudinal inner loop control design of a flexible aircraft over a large flight domain. More precisely, the objective is to construct a stabilizing flight control law to steer the angle of attack to a desired trim value while suppressing the oscillation of the bending modes. A new Lyapunov-based non-linear controller is designed to enhance the transient of the flexible modes before reaching the zero dynamics sub-manifold. Moreover, the local behavior of the trajectories is finally modified by blending our controller with a LQ controller in order to achieve the additional and practical control objective of locally damping out the oscillations of the bending modes.