Control of a satellite with flexible smart beam during slew maneuver

Ürek, Halime
In this thesis, an attitude control system based on Linear Quadratic Regulator (LQR) technique is developed for a hypothetical Earth observation satellite with a long flexible boom. To improve pointing performance of the satellite, the piezoelectric actuators are used as well. The boom is rectangular made of aluminum with the surface bonded piezoelectric layers on all four surfaces. The boom is modeled using finite elements. The pointing performance of the satellite using various metrics is evaluated through simulations. Effectiveness of the piezoelectric actuators is demonstrated.


Satellite orbit estimation using kalman filters
İpek, Mehmet; Orguner, Umut; Department of Electrical and Electronics Engineering (2017)
In this thesis, satellite orbit determination problem is investigated using various types of Kalman filters based on several ground and space based measurement types. First, the performance of the Gauss' method for initial orbit determination is evaluated and the measurement time separation values required for it to give sufficiently good estimates are determined. Second, filter initialization methods based on a few measurements are proposed for angles only (AE), angles and range (AER), angles and Doppler (...
Development of control allocation methods for satellite attitude control
Elmas, Tuba Çiğdem; Tekinalp, Ozan; Department of Aerospace Engineering (2010)
This thesis addresses the attitude control of satellites with similar and dissimilar actuators and control allocation methods on maneuvering. In addition, the control moment gyro (CMG) steering with gyroscopes having limited gimbal angle travel is also addressed. Full Momentum envelopes for a cluster of four CMG's are obtained in a pyramid type mounting arrangement. The envelopes when gimbal travel is limited to plus-minus 90 degree are also obtained. The steering simulations using Moore Penrose (MP) pseudo...
Development of a tool for prediction of the orbital parameters of earth observation satellites
Altay, Alkan; Karsli, Gizem; Oezkan, Ahmet (2007-06-16)
Development of a tool that predicts the orbital parameters of a satellite from an initial state vector for a specified time interval is addressed. The elements used in the algorithm are presented. The prediction performance of the algorithm is demonstrated by using the two line elements of a GPS satellite and the CHAMP scientific satellite.
Forecasting of ionospheric electron density trough for characterization of aerospace medium
Kocabaş, Zeynep; Tulunay, Yurdanur; Department of Aerospace Engineering (2009)
Modeling the ionosphere, where the effects of solar dynamo becomes more effective to space based and ground borne activities, has an undeniable importance for telecommunication and navigation purposes. Mid-latitude electron density trough is an interesting phenomenon in characterizing the behavior of the ionosphere, especially during disturbed conditions. Modeling the mid-latitude electron density trough is a very popular research subject which has been studied by several researchers until now. In this work...
Trajectory computation of small solid particles released and carried by flowfields of helicopters in forward flight
Pekel, Yusuf Okan; Özyörük, Yusuf; Department of Aerospace Engineering (2010)
In this thesis, trajectory computations of chaff particles ejected from a medium weight utility helicopter are performed using computational fluid dynamics. Since these chaff particles are ejected from a helicopter and carried by its flow field, it is necessary to compute and include the effects of the helicopter flow field in general and engine hot gases, main and tail rotor wakes in particular. The commercial code FLUENT is used for flow field and trajectory computations. Both main rotor and tail rotor ar...
Citation Formats
H. Ürek, “Control of a satellite with flexible smart beam during slew maneuver,” M.S. - Master of Science, Middle East Technical University, 2011.