Modal Control -Application to the piloting of a plane

In the world of aeronautics, particularly since the advent of fly-by-wire (FBW) flight controls, modal control theory has been successfully applied to the tuning of flight control laws. Even today, civil aircraft autopilot remains the flagship application, providing a simple illustration of the potential of these techniques.

After a few theoretical reminders and details on how to improve the robustness of modal control laws, we propose in this article a relatively complete application to an autopilot problem in the landing phase. From a control point of view, this phase of flight is particularly demanding in terms of the accuracy required for the variables being controlled. Particular attention will therefore be paid to the sensitivity of control laws to external disturbances (wind, atmospheric turbulence) on the one hand, and to model variations (mass, centering) on the other. We'll start by proposing a classical solution, followed by various ways of improving the initial settings.