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

Download

index.pdf

Date

2018

Author

Şeref, Tuğçe

Metadata

Show full item record

Item Usage Stats

406
views

119
downloads

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.

Subject Keywords

Antennas (Electronics)., Aperture antennas., PID controllers.

URI

http://etd.lib.metu.edu.tr/upload/12622570/index.pdf
https://hdl.handle.net/11511/27514

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Cogging Torque Disturbance Rejection for a Low-cost Gimbal Motor and a Controller Design with Practical Considerations Ozdogan, Gokhan; Leblebicioğlu, Mehmet Kemal (2019-01-01) In many robotic applications and inertially stabilized electro-optic gimbal systems, precise positioning and speed control are highly important concepts. Due to size and weight limitations, motor is required to be small but torque density is desired to be high. In high torque and cheap PMSM and BLDC motors, cogging torque and friction are usually the challenging disturbance sources. In this study, cogging torque and friction are identified using position sensors which already exist in gimbal systems, so the...
Theoretical investigation and design of wideband dielectric resonator antennas Yüksel, Yılmaz Çağrı; Alatan, Lale; Department of Electrical and Electronics Engineering (2015) The aim of this thesis is to utilize Dielectric Resonator Antennas (DRA) as array elements due to their advantages over other conventional antenna elements such as dipoles and microstrip patches. Depending on both the excitation mechanisms and the antenna shape, a Dielectric Resonator Antenna (DRA) provides its designer multiple independent degrees of freedom. In this thesis three antenna shapes, namely hemispherical, cylindrical and rectangular DRAs, are investigated. The cylindrical and the rectangular sh...
ISAR imaging and motion compensation Küçükkılıç, Talip; Dural Ünver, Mevlüde Gülbin; Department of Electrical and Electronics Engineering (2006) In Inverse Synthetic Aperture Radar (ISAR) systems the motion of the target can be classified in two main categories: Translational Motion and Rotational Motion. A small degree of rotational motion is required in order to generate the synthetic aperture of the ISAR systems. On the other hand, the remaining part of the target’s motion, that is any degree of translational motion and the large degree of rotational motion, degrades ISAR image quality. Motion compensation techniques focus on eliminating the effe...
An Investigation of beam scanning of arrays on cylindrical, conical and spherical surfaces Takak, Yücel; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2015) Recently, wide angle scanning antennas are often required especially in many radar applications. It is known that planar arrays have limited scan range without beam deformation. In this study design and production steps for wide angle scanning antenna arrays conformed on cylindrical, conical and spherical surfaces that operate at X-Band are investigated. Antenna elements used in these conformal arrays are designed using full wave electromagnetic solver tool HFSS. A MATLAB code for obtaining array patterns i...
ON THE ELIMINATION OF INFINITIES IN THE PO COMPONENT OF EQUIVALENT EDGE CURRENTS OGUZER, T; ALTINTAS, A; BUYUKDURA, OM (1993-10-01) Equivalent edge currents for the Physical Optics (PO) contribution to the edge diffraction are derived by choosing a proper coordinate system for a half plane. It is seen that these expressions for the PO component are free from singularities except at shadow and reflection boundaries on the Keller Cone. To find the total diffracted field, the expressions for the fringe contribution given earlier by Michaeli should be used along with the PO contribution obtained here. The procedure is applied to the problem...

Citation Formats

T. Şeref, “Dynamic modelling and control of a gimballed airborne antenna platform with mass unbalance and friction,” M.S. - Master of Science, Middle East Technical University, 2018.