Nonlinear controller designs for a reaction wheel actuated observatory satellite

Download

index.pdf

Date

2008

Author

Doruk, Reşat Özgür

Metadata

Show full item record

Item Usage Stats

246
views

125
downloads

In this research, nonlinear attitude controllers are designed for a low earth orbit satellite intended to be used in observatory missions. The attitude is represented by the Modified Rodriguez Parameters (MRP) which is a minimal representation providing a fully invertible kinematics. As a difference from the classical satellite models existent in the literature, the model of this work incorporates the dynamics of the reaction wheel (actuator) including a brushless dc motor which is armature controlled. The total model has four group of state vectors which are the attitude, body rates, actuator torque and velocity. The main control approach of this research is developed by utilizing integrator back - stepping which provides a recursive stabilization methodology to the designer. For performance comparison, a second controller based on input output feedback linearization (IOFL) is presented. Both of the approaches produce a torque demand law and this is used for generating a desired reaction wheel velocity command. A reaction wheel controller uses the motor as the actuator and produces the necessary amount of the torque according to the desired wheel velocity command. In addition for the back - stepping based approach, a stability analysis against the external disturbance torques is also provided. Simulations are presented for validating the performance and robustness of the proposed controllers.

Subject Keywords

Electrical engineering., Satellites.

URI

http://etd.lib.metu.edu.tr/upload/12609831/index.pdf
https://hdl.handle.net/11511/17971

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Power stage design and implementation of a deploymentmechanism driver for space applications Özdemir, Başak Gonca; Hızal, Mirzahan; Department of Electrical and Electronics Engineering (2012) With the developments in space technology, the capabilities of spacecrafts have been increased considerably which in turn have entailed the development of more efficient spacecrafts in terms of cost, mass, size and power. One way to achieve such a development is the replacement of body mounted appendages with the deployable ones, which greatly reduces the size, mass and cost of the spacecraft especially when large appendages are considered. In order to obtain these deployable structures, deployment mechanis...
Interference suppression by using space-time adaptive processing for airborne radar Eryiğit, Özgür; Yılmaz, Ali Özgür; Department of Electrical and Electronics Engineering (2008) Space-Time Adaptive Processing (STAP) is an effective method in Ground Moving Target Indicator (GMTI) operation of airborne radars. Clutter suppression is the key to successful MTI operation. Airborne radars are different than the ground based ones in regard to clutter due to the displacement of the platform during operation. When STAP methods are to be investigated, one needs to have accurate signal models while evaluating performance. In this thesis, a comprehensive received signal model is developed firs...
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...
Tracker-aware detection : a theoretical and an experimental study Aslan, Murat Şamil; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2009) A promising line of research attempts to bridge the gap between detector and tracker by means of considering jointly optimal parameter settings for both of these subsystems. Along this fruitful path, this thesis study focuses on the problem of detection threshold optimization in a tracker-aware manner so that a feedback from the tracker to the detector is established to maximize the overall system performance. Special emphasis is given to the optimization schemes based on two non-simulation performance pred...
Development and comparison of autopilot and guidance algorithms for missiles Evcimen, Çağdaş; Leblebicioğlu, Mehmet Kemal; Department of Electrical and Electronics Engineering (2007) In order to have an interception with a target, a missile should be guided with a successful guidance algorithm accompanied with a suitable autopilot structure. In this study, different autopilot and guidance designs for a canard-controlled missile are developed. As a first step, nonlinear missile mathematical model is derived by using the equations of motion with aerodynamic coefficients found by Missile DATCOM program. Autopilot design starts by the linearization of the nonlinear missile model around equi...

Citation Formats

R. Ö. Doruk, “Nonlinear controller designs for a reaction wheel actuated observatory satellite,” Ph.D. - Doctoral Program, Middle East Technical University, 2008.