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Virginia Tech

H<sub>∞</sub> and LQG optimal control for the rejection of persistent disturbances: analysis, design and experiment

Abstract

dc:description.abstract

This dissertation presents a discussion of the asymptotic behavior and estimation structure of the H<sub>∞</sub> central controllers in terms of the well-known behavior of the LQG controller and gives some insight into the physics of the H<sub>∞</sub> controller that is often presented in an unclear manner in the current literature. The connections to LQ game theory that underlie this confusion are discussed. Augmented systems that are typically used in disturbance rejection problems are also analyzed. Additionally, a controlled output equation for disturbance rejection is developed based on the physics of the problem rather than the typical ad hoc approaches of the past. These controlled output equations are also appropriate for LQG compensators. In order to verify the proposed approach, an experiment in harmonic and narrowband disturbance rejection using a simply supported steel plate is presented. Discrete-time LQG, and continuous-time H<sub>∞</sub> and LQG controllers that have been transformed to discrete-time are used to determine the attainable performance of each approach. The results indicate that the H<sub>∞</sub> controller provides more damping than either LQG approach and that discrete-time design procedures are necessary for maximum disturbance rejection.

Degree

thesis:*
Name thesis:degree_name
Ph. D.
Level thesis:degree_level
doctoral
Discipline thesis:degree_discipline
Mechanical Engineering
Department dc:contributor.department
Mechanical Engineering
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
1992

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Ellis, Graham K.
Chair dc:contributor.committeechair
  • Robertshaw, Harry H.
Committee members dc:contributor.committeemember
  • Leonard, Robert G.
  • Russell, David L.
  • Wicks, Alfred L.
  • Baumann, William T.

Rights

dc:rights
Statement dc:rights
  • In Copyright
Language dc:language.iso
en

Identifiers

dc:identifier.*
Dc Identifier Other
etd-02012006-141752
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/37266

Chain of custody

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Harvested from
Virginia Tech
Base URL
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Last updated
2026-07-22
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citation

Ellis, Graham K.. H<sub>∞</sub> and LQG optimal control for the rejection of persistent disturbances: analysis, design and experiment. doctoral thesis, Virginia Tech, 1992. http://hdl.handle.net/10919/37266