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Controlling the Secondary Mirror Cell of the Euro50 Project using an Inertial Measurement Unit

Sandberg, Olof (2005) In MSc Theses
Department of Automatic Control
Abstract
When building a telescope, importance does not only lie on the optical performance. Keeping the entire structure stable is also of great importance. In the case of the Euro50, the secondary mirror cell will be located some 60 m above ground level, exposed of wind speeds up to 15 m/s. This makes the stabilization of the mirror cell to a dicult problem. However, it has to be solved. <p> The main goal of this master thesis is to develop a controller to stabilize the secondary mirror cell of the Euro50 extremely large telescope. The approach is to use an inertial measurement unit, consisting of gyros and accelermeters, for position feedback. This approach has been evaluated before, with the conclusion that no long sample times can be made due... (More)
When building a telescope, importance does not only lie on the optical performance. Keeping the entire structure stable is also of great importance. In the case of the Euro50, the secondary mirror cell will be located some 60 m above ground level, exposed of wind speeds up to 15 m/s. This makes the stabilization of the mirror cell to a dicult problem. However, it has to be solved. <p> The main goal of this master thesis is to develop a controller to stabilize the secondary mirror cell of the Euro50 extremely large telescope. The approach is to use an inertial measurement unit, consisting of gyros and accelermeters, for position feedback. This approach has been evaluated before, with the conclusion that no long sample times can be made due to noise in the feedback. Here, a wavefront sensor is used to create additional position feedback, thus allowing the long sample times required. Favourably, more than one controller should be derived, to give the Euro50 developers more freedom of choise. Also, the noise charateristics of the inertial measurement unit are to be investigated, to give recommendations of the performance needed. <p> This master thesis is one of three closely related projects involving the secondary mirror cell of the Euro50 telescope. The others are Modeling and Control of a Large Deformable Mirror, and Actuator servos for Deformable Mirrors. (Less)
Please use this url to cite or link to this publication:
author
Sandberg, Olof
supervisor
organization
year
type
H3 - Professional qualifications (4 Years - )
subject
publication/series
MSc Theses
report number
TFRT-5750
ISSN
0280-5316
language
English
id
8847938
date added to LUP
2016-03-18 09:56:27
date last changed
2016-03-18 09:56:27
@misc{8847938,
  abstract     = {{When building a telescope, importance does not only lie on the optical performance. Keeping the entire structure stable is also of great importance. In the case of the Euro50, the secondary mirror cell will be located some 60 m above ground level, exposed of wind speeds up to 15 m/s. This makes the stabilization of the mirror cell to a dicult problem. However, it has to be solved. <p> The main goal of this master thesis is to develop a controller to stabilize the secondary mirror cell of the Euro50 extremely large telescope. The approach is to use an inertial measurement unit, consisting of gyros and accelermeters, for position feedback. This approach has been evaluated before, with the conclusion that no long sample times can be made due to noise in the feedback. Here, a wavefront sensor is used to create additional position feedback, thus allowing the long sample times required. Favourably, more than one controller should be derived, to give the Euro50 developers more freedom of choise. Also, the noise charateristics of the inertial measurement unit are to be investigated, to give recommendations of the performance needed. <p> This master thesis is one of three closely related projects involving the secondary mirror cell of the Euro50 telescope. The others are Modeling and Control of a Large Deformable Mirror, and Actuator servos for Deformable Mirrors.}},
  author       = {{Sandberg, Olof}},
  issn         = {{0280-5316}},
  language     = {{eng}},
  note         = {{Student Paper}},
  series       = {{MSc Theses}},
  title        = {{Controlling the Secondary Mirror Cell of the Euro50 Project using an Inertial Measurement Unit}},
  year         = {{2005}},
}