Fault tolerant flight control applications for a fixed wing UAV using linear and nonlinear approaches

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Havacılık ve Uzay Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2019

Öğrenci: BURAK ERGÖÇMEN

Danışman: İLKAY YAVRUCUK

Özet:

Control surface or actuator faults or failures in any flight, lead to system-induced loss of control in flight (LOC-I) and results can be fatal. In this thesis, to prevent these accidents, an active fault-tolerant flight control (FTFC) is proposed. The system consists of the nonlinear control technique, state-dependent Riccati equation (SDRE) and linear controller techniques. Besides, examples for emergency cases; control surface damage, degradation, stuck and turbulence are studied for different levels. In addition, if there is a problem with regard to the construction of the state-dependent coefficient (SDC) matrices for SDRE controller, the solution is to change to a Linear Quadratic Regulator (LQR) and Linear Quadratic Tracking (LQT). To prevent these emergencies, a Reconfigure Mechanism (RM) sends signals in real-time to the SDRE controller to slow down or accelerate the control surface movement or change to LQR/LQT controller to prevent LOC-I. Comparative figures are given to illustrate the effectiveness of the hybrid controller architecture.