H₂/H∞ mixed robust controller synthesis for a fin actuation system

Ölçer, Tuncay Uğurlu
In fin actuation systems, the performance of classical linear control systems is not satisfactory due to uncertainty of the system parameters and disturbances of the working medium. For this reason, sliding mode, H2 or H∞ robust controllers are widely used in literature for such systems. However, use of such controllers results in very conservative system responses. Based on this fact, in this thesis, development of a more effective robust controller is aimed via integration of the optimum properties of the existent pure H2 and H∞ type robust controllers. To achieve this, during the controller synthesizing procedure, some of the optimization parameters are weighted according to H2 norm minimization, and parameter uncertainties and other variables are weighted according to H∞ theorem. First, the system set up to be controlled is physically constructed and performed system identification processes. Then, two different types of robust controllers H2 and H∞ controllers are designed and tested over both the real system and simulation. Finally an H2/H∞ mixed type controller synthesized and the results are compared with the outputs of the robust controllers of the previous step.


Leo satellites: attitude determination and control components; some linear attitude control techniques
Kaplan, Ceren; Kocaoğlan, Erol; Department of Electrical and Electronics Engineering (2006)
In this thesis, application of linear control methods to control the attitude of a Low-Earth Orbit satellite is studied. Attitude control subsystem is first introduced by explaining attitude determination and control components in detail. Satellite dynamic equations are derived and linearized for controller design. Linear controller and linear quadratic regulator are chosen as controllers for attitude control. The actuators used for control are reaction wheels and magnetic torquers. MATLAB-SIMULINK program ...
Adaptive output feedback control with reduced sensitivity to sensor noise
Kutay, Ali Türker; Hovakimyan, N (2003-01-01)
We address adaptive output feedback control of uncertain nonlinear systems with noisy output measurements, in which both the dynamics and the dimension of the regulated system may be unknown, and only the relative degree of the regulated output is assumed to be known. Given a smooth reference trajectory, the problem is to design a controller that forces the system measurement to track it with bounded errors. A recently developed method proposes the use of a linear error observer that estimates the tracking ...
Time-domain calculation of sound propagation in lined ducts with sheared flows
Özyörük, Yusuf (1999-01-01)
A recent application of the time-domain equivalent of the classical acoustic impedance condition, i.e. the particle displacement continuity equation, to the numerical simulations of a flow-impedance tube in the time domain yielded reasonably good results with uniform mean flows. The present paper extends this application to include sheared mean flow effects on sound propagation over acoustically treated walls. To assess the prediction improvements with sheared flows, especially at relatively high Mach numbe...
Advances in robust identification of spline models and networks by robust conic optimization, with applications to different sectors
Özmen, Ayşe; Wilhelm Weber, Gerhard; Department of Scientific Computing (2015)
Uncertainty is one of the characteristic properties in the area of high-tech engineering and the environment, but also in finance and insurance, as the given data, in both input and output variables, are affected with noise of various kinds, and the scenarios which represent the developments in time, are not deterministic either. Since the global environmental and economic crisis has caused the necessity for an essential restructuring of the approach to risk and regulation in these areas, core elements of n...
Linear parameter varying control for autonomous systems: methods and application examples
Çalış, Fatih; Schmidt, Klaus Verner; Department of Electrical and Electronics Engineering (2022-8-24)
Linear parameter varying (LPV) systems are nonlinear systems which can be modelled as linear systems whose parameters change as a function of different "scheduling parameters". In other words, the dynamics of the LPV systems change during the operation hence they require a parameter dependent controller. Although classical gain-scheduling approaches satisfy some performance criteria for constant dynamics, they don't guarantee stability while the scheduling parameter is changing. On the other hand, H∞-norm b...
Citation Formats
T. U. Ölçer, “H₂/H∞ mixed robust controller synthesis for a fin actuation system,” M.S. - Master of Science, Middle East Technical University, 2013.