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Controls and Control Theory Commons

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Full-Text Articles in Controls and Control Theory

Robust And Adaptive Attitude Control Of Spacecraft Using Solar Radiation Pressure, Lakshmi Srinivasan Dec 2013

Robust And Adaptive Attitude Control Of Spacecraft Using Solar Radiation Pressure, Lakshmi Srinivasan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Satellites in orbit are expected to maintain a preset attitude either pointing towards Earth (in case of satellites for weather) or pointing towards space for the purpose of research and exploration. The satellite as a system though is extremely nonlinear and the system parameters are not easily available. The goal of this thesis is to develop robust and adaptive control laws that can be used to control the attitude of satellites in elliptic orbits. The attitude of the satellite is controlled by the use of Solar Radiation Pressure (SRP) on the solar panels of the satellite. The SRP is basically …


Control Studies Of Dfig Based Wind Power Systems, Zhiqiang Jin Aug 2013

Control Studies Of Dfig Based Wind Power Systems, Zhiqiang Jin

Doctoral Dissertations

Wind energy as an outstanding and competitive form of renewable energy, has been growing fast worldwide in recent years because of its importance to reduce the pollutant emission generated by conventional thermal power plants and the rising prices and the unstable supplies of fossil-fuel. However, in the development of wind energy, there are still many ongoing challenges.

An important challenge is the need of voltage control to maintain the terminal voltage of a wind plant to make it a PV bus like conventional generators with excitation control. In the literature with PI controllers used, the parameters of PI controllers need …


Adaptive Control Of Apache Web Server, Erik Reed, Abe Ishihara, Ole J. Mengshoel May 2013

Adaptive Control Of Apache Web Server, Erik Reed, Abe Ishihara, Ole J. Mengshoel

Ole J Mengshoel

Traffic to a Web site can vary dramatically. At the same time it is highly desirable that a Web site is reactive. To provide crisp interaction on thin clients, 150 milliseconds has been suggested as an upper bound on response time. Unfortunately, the popular Apache Web server is limited in its capabilities to be reactive under varying traffic. To address this problem, we design in this paper an adaptive controller for the Apache Web server. A modified recursive least squares algorithm is used to identify system dynamics and a minimum degree pole placement controller is implemented to adjust the maximum …


Decentralized Adaptive Control For Uncertain Linear Systems: Techniques With Local Full-State Feedback Or Local Relative-Degree-One Output Feedback, James D. Polston Jan 2013

Decentralized Adaptive Control For Uncertain Linear Systems: Techniques With Local Full-State Feedback Or Local Relative-Degree-One Output Feedback, James D. Polston

Theses and Dissertations--Mechanical Engineering

This thesis presents decentralized model reference adaptive control techniques for systems with full-state feedback and systems with output feedback. The controllers are strictly decentralized, that is, each local controller uses feedback from only local subsystems and no information is shared between local controllers.

The full-state feedback decentralized controller is effective for multi-input systems, where the dynamics matrix and control-input matrix are unknown. The decentralized controller achieves asymptotic stabilization and command following in the presence of sinusoidal disturbances with known spectrum. We present a construction technique of the reference-model dynamics such that the decentralized controller is effective for systems with arbitrarily …