Özet:
Probably the most important part during a flight is the landing phase because most
of the accidents occur in this phase. Automatic Landing System (ALS) takes over
control during this phase to avoid potential pilot-induced risks. However, some
external disturbances, such as the windshear and turbulence, can jeopardize the safe
landing. In this study, the final approach phase and flare phase are handled differently.
A combination of some useful design methods is brought together to improve the
performance of the conventional ALS even under severe weather conditions. The
model following method is merged with the H∞ synthesis method to find out the
optimal solution for a given cost function. The resultant H∞ optimal control problem
is solved using Linear Matrix Inequalities (LMIs), and then a dynamic controller is
constructed. The overall system is transformed into a P-K configuration, which is a
highly compact control system structure. Thus, any disturbance or uncertainties can
be included in the system explicitly. While the model following method continuously
corrects the error, the H∞ controller attenuates any disturbance in the system. In
addition to that, the robustness takes a vital role in the flight systems and needs to be
handled correctly. Therefore, the windshear and turbulence models are considered
as the disturbance, and their effects are minimized, such a way that the tracking
performance remains unaffected. Thus, highly significant results are obtained using
the proposed method even under severe weather conditions.
