Atas, Omer
Tekinalp, Ozan
Solar sailing where the radiation pressure from Sun is utilized to propel the spacecraft is examined in the context of orbital maneuvers. In this vein a locally optimal steering law to progressively change the selected orbital elements, without considering others, of an Earth centered Keplerian orbit of a cubesat satellite with solar sail is addressed. The proper attitude maneuver mechanization is proposed to harvest highest solar radiation force in the desired direction for such Earth orbiting satellites. The satellite attitude control is realized using quaternion error feedback control. The effectiveness of the approach to progressively changing the orbital parameters is demonstrated.


Accurate position control of a flapping-wing robot enabling free-flight flow visualisation in a wind tunnel
Karasek, Matej; Perçin, Mustafa; Cunis, Torbjorn; van Oudheusden, Bas W.; De Wagter, Christophe; Remes, Bart D. W.; de Croon, Guido C. H. E. (SAGE Publications, 2019-10-02)
Flow visualisations are essential to better understand the unsteady aerodynamics of flapping wing flight. The issues inherent to animal experiments, such as poor controllability and unnatural flapping when tethered, can be avoided by using robotic flyers that promise for a more systematic and repeatable methodology. Here, we present a new flapping-wing micro air vehicle (FWMAV)-specific control approach that, by employing an external motion tracking system, achieved autonomous wind tunnel flight with a maxi...
Near-surface topology and flow structure on a delta wing
Yavuz, Mehmet Metin; Rockwell, D (American Institute of Aeronautics and Astronautics (AIAA), 2004-02-01)
The streamlines, and the corresponding patterns of velocity and vorticity, are characterized on a plane immediately adjacent to the surface of a delta wing using a laser-based technique of high-image-density particle image velocimetry. This technique provides the sequence of instantaneous states, as well as the corresponding time-averaged state, of the near-surface streamline topology and the associated critical points. These topological features are interpreted in terms of patterns of averaged and unsteady...
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...
Flight simulation and control of a helicopter
Erçin, Gülsüm Hilal; Tekinalp, Ozan; Department of Aerospace Engineering (2008)
In this thesis the development of a nonlinear simulation model of a utility helicopter and the design of its automatic flight control system is addressed. In the first part of this thesis, the nonlinear dynamic model for a full size helicopter is developed using the MATLAB/SIMULINK environment. The main rotor (composed of inflow and flapping dynamics parts), tail rotor, fuselage, vertical stabilizer, horizontal stabilizer of the helicopter are modeled in order to obtain the total forces and moments needed f...
Mathematical model development of the anti torque system of a notar helicopter
Bakır, Hüseyin Murat; Yavrucuk, İlkay; Department of Aerospace Engineering (2008)
The anti-torque mechanism of a NOTAR helicopter is a complex system including vertical tail and pressurized tail boom which provides air ejection used for both circulation control around the boom and creating directed jet air at the end of the boom. This thesis targets the modeling of this mechanism and integrating it to a helicopter simulation model. Flight tests are performed on the MD 600N helicopter to verify the results. Finally, the simulation is compared with flight test data.
Citation Formats
O. Atas and O. Tekinalp, “ATTITUDE CONTROL OF AN EARTH ORBITING SOLAR SAIL SATELLITE TO PROGRESSIVELY CHANGE THE SELECTED ORBITAL ELEMENT,” Virginia, Amerika Birleşik Devletleri, 2015, vol. 155, Accessed: 00, 2020. [Online]. Available: