Dynamic modelling and control of a gimballed airborne antenna platform with mass unbalance and friction

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2018

Öğrenci: TUĞÇE KOBAL

Danışman: MEHMET KEMAL LEBLEBİCİOĞLU

Özet:

Inertial stabilized gimballed systems are widely-used in many applications to achieve a high precision positioning. Airborne antennas pointing target as a part of the satellite communication may be examples of such systems. This thesis presents the dynamic modelling and control of a two axes gimballed airborne antenna platform. First, reference frames and the transformation matrices are defined to build up the motion of the antenna and kinematic equations of each gimbal are derived. Next, the dynamic equations including mass unbalance of the gimbals and the friction torques about pivot points are obtained. Then, the study puts emphasis on the concepts of the static and dynamic mass unbalance and also argues how much each mass unbalance affects the operation. Furthermore, a dynamic model, Lugre friction, establishes the friction torques for both of the gimbals. All these studies results in the complete dynamic model of the two axes gimballed airborne antenna platform. The overall system model is implemented inMATLAB/Simulink environment. Next, system identification studies to determine the parameters of the Lugre friction model have been performed by two different methods based on real and simulated data. Finally, PI based controllers have been designed for the overall system in several design stages.