Dr. Roger M. Glaese Profile

Dr. Roger M. Glaese

at Moog CSA Engineering

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Publications (8)

Proceedings Article | 17 September 2012 Paper

Vibration mitigation for wind-induced jitter for the Giant Magellan Telescope

Roger Glaese, Michael Sheehan

Proceedings Volume 8444, 84440V (2012) https://doi.org/10.1117/12.926337

KEYWORDS: Telescopes, Actuators, Sensors, Mirrors, Finite element methods, Received signal strength, Optical instrument design, MATLAB, Control systems, Inspection

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The Giant Magellan Telescope (GMT) is a planned large terrestrial telescope with a segmented primary mirror with a 24.5 meter overall diameter. Like most terrestrial telescopes, the GMT resides within an enclosure designed to protect the telescope from the elements and to reduce the effects of wind on the optical performance of the telescope. Wind impingement on the telescope causes static deformation and vibration in the telescope structure that affects the alignment and image jitter performance of the telescope. Actively controlled primary mirror segments and a secondary mirror can correct for the static and low frequency portions of the wind effects, but typically the actuators do not have the bandwidth to address higher frequency components of the wind environment. Preliminary analyses on the GMT indicate that the image jitter associated with wind effects meets budgeted allowances but without much margin. Preliminary models show that the bulk of the residual jitter arises from excitation of a small number of modes in the 9 to 12 Hz range. Therefore, as a risk mitigation effort to increase the margin on the wind induced jitter, passive and active vibration mitigation approaches have been examined for the GMT, which will be the focus of this paper. Using a finite element model of the GMT along with wind loading load cases, several passive and active vibration mitigation approaches were analyzed. These approaches include passive approaches such as tuned mass dampers targeting the worst offending modes, and constrained layer damping targeting all of the modes within the troublesome frequency range. Active approaches evaluated include two active damping approaches, one using several reaction mass actuators and the other using active strut type actuators. The results of the study show that although all approaches are successful in reducing the jitter, the active damping approach using reaction mass actuators offers the lightest weight, least implementation impact, and most adaptability of any of the approaches.

Proceedings Article | 10 July 2008 Paper

A comparison of vibration damping methods for ground based telescopes

Eric Anderson, Roger Glaese, Douglas Neill

Proceedings Volume 7012, 70120H (2008) https://doi.org/10.1117/12.790195

KEYWORDS: Telescopes, Actuators, Large Synoptic Survey Telescope, Mirrors, Space telescopes, Sensors, Optical instrument design, Vibration isolation, Finite element methods, Vibration control

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Proceedings Article | 10 May 2007 Paper

Adaptive filtering and feed-forward control for suppression of vibration and jitter

Eric Anderson, Ross Blankinship, Leslie Fowler, Roger Glaese, Paul Janzen

Proceedings Volume 6569, 65690Q (2007) https://doi.org/10.1117/12.718890

KEYWORDS: Control systems, Sensors, Digital filtering, Cryocoolers, Actuators, Filtering (signal processing), Mirrors, Acoustics, Servomechanisms, Digital signal processing

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Proceedings Article | 31 August 2001 Paper

Image stabilization testbed (ISTAT)

Eric Anderson, Michael Evert, Patrick Flannery, Bryce Fowler, Roger Glaese, Paul Janzen

Proceedings Volume 4366, (2001) https://doi.org/10.1117/12.438073

KEYWORDS: Actuators, Digital signal processing, Control systems, Fermium, Frequency modulation, Analog electronics, Human-machine interfaces, Missiles, Feedback control, Signal processing

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Proceedings Article | 2 July 2001 Paper

Damping SOFIA: passive and active damping for the Stratospheric Observatory for Infrared Astronomy

Joseph Maly, Paul Keas, Roger Glaese

Proceedings Volume 4331, (2001) https://doi.org/10.1117/12.432734

KEYWORDS: Telescopes, Mirrors, Space telescopes, Actuators, Infrared astronomy, Motion models, Gyroscopes, Control systems, Observatories, Finite element methods

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Proceedings Article | 21 July 2000 Paper

Active suppression of acoustically induced jitter for the airborne laser

Roger Glaese, Eric Anderson, Paul Janzen

Proceedings Volume 4034, (2000) https://doi.org/10.1117/12.391865

KEYWORDS: Acoustics, Sensors, Mirrors, Actuators, Feedback control, Airborne laser technology, Control systems, Sensor performance, Servomechanisms, Digital signal processing

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Proceedings Article | 9 July 1999 Paper

Satellite ultraquiet isolation technology experiment (SUITE): electromechanical subsystems

Eric Anderson, Michael Evert, Roger Glaese, James Goodding, Scott Pendleton, Donald Camp, John Fumo, Marty Jessen, Richard Cobb, R. Scott Erwin, Jonathon Jensen

Proceedings Volume 3674, (1999) https://doi.org/10.1117/12.351568

KEYWORDS: Satellites, Sensors, Actuators, Space operations, Vibration isolation, Digital signal processing, Magnetism, Control systems, Signal processing, Passive isolation

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Proceedings Article | 9 June 1999 Paper

Active structural-acoustic control for composite payload fairings

Roger Glaese, Eric Anderson

Proceedings Volume 3668, (1999) https://doi.org/10.1117/12.350723

KEYWORDS: Acoustics, Stars, Actuators, Sensors, Composites, Data modeling, Finite element methods, Signal attenuation, Feedback control, Performance modeling

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Showing 5 of 8 publications

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