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Progress in Developing a Low-Cost Large Deformable Mirror

Heimsten, Rikard LU ; MacMynowski, Douglas G. and Andersen, Torben LU (2010) Conference on Adaptive Optics Systems II In Adaptive Optics Systems II 7736.
Abstract
Large (> 1m) deformable mirrors with hundreds or thousands of actuators are attractive for extremely large telescopes. Use of force actuators coupled to the mirror via suction cups, and electret microphones for position sensing, has the potential of substantially reducing costs. However, a mirror controlled with force actuators will have many structural resonances within the desired system bandwidth, shifting the emphasis somewhat of the control aspects. Local velocity and position loop for each actuator can add significant damping, but gives poor performance at high spatial frequencies. We therefore introduce a novel control strategy with many parallel "actuator families", each controlled by single-input-single-output controllers. This... (More)
Large (> 1m) deformable mirrors with hundreds or thousands of actuators are attractive for extremely large telescopes. Use of force actuators coupled to the mirror via suction cups, and electret microphones for position sensing, has the potential of substantially reducing costs. However, a mirror controlled with force actuators will have many structural resonances within the desired system bandwidth, shifting the emphasis somewhat of the control aspects. Local velocity and position loop for each actuator can add significant damping, but gives poor performance at high spatial frequencies. We therefore introduce a novel control strategy with many parallel "actuator families", each controlled by single-input-single-output controllers. This family approach provides performance close to that of global control, but without the accompanying robustness challenges. Using a complete simulation model of a representative large deformable mirror, we demonstrate feasibility of the approach. This paper describes the challenges of non-ideal actuators and sensors. The results presented give an understanding of the required actuator bandwidth and the effects of the sensors dynamics. The conclusion is that the introduction of actuator and sensor dynamics does not limit the control system of the deformable mirror. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Adaptive Optics Systems II
volume
7736
publisher
SPIE
conference name
Conference on Adaptive Optics Systems II
external identifiers
  • wos:000285506400189
  • scopus:77957829508
ISSN
0277-786X
1996-756X
DOI
10.1117/12.855054
language
English
LU publication?
yes
id
5045c278-bddf-4643-b8ab-22b3bcbe1404 (old id 1868108)
date added to LUP
2011-04-20 10:48:28
date last changed
2018-05-29 10:26:44
@inproceedings{5045c278-bddf-4643-b8ab-22b3bcbe1404,
  abstract     = {Large (> 1m) deformable mirrors with hundreds or thousands of actuators are attractive for extremely large telescopes. Use of force actuators coupled to the mirror via suction cups, and electret microphones for position sensing, has the potential of substantially reducing costs. However, a mirror controlled with force actuators will have many structural resonances within the desired system bandwidth, shifting the emphasis somewhat of the control aspects. Local velocity and position loop for each actuator can add significant damping, but gives poor performance at high spatial frequencies. We therefore introduce a novel control strategy with many parallel "actuator families", each controlled by single-input-single-output controllers. This family approach provides performance close to that of global control, but without the accompanying robustness challenges. Using a complete simulation model of a representative large deformable mirror, we demonstrate feasibility of the approach. This paper describes the challenges of non-ideal actuators and sensors. The results presented give an understanding of the required actuator bandwidth and the effects of the sensors dynamics. The conclusion is that the introduction of actuator and sensor dynamics does not limit the control system of the deformable mirror.},
  author       = {Heimsten, Rikard and MacMynowski, Douglas G. and Andersen, Torben},
  booktitle    = {Adaptive Optics Systems II},
  issn         = {0277-786X},
  language     = {eng},
  publisher    = {SPIE},
  title        = {Progress in Developing a Low-Cost Large Deformable Mirror},
  url          = {http://dx.doi.org/10.1117/12.855054},
  volume       = {7736},
  year         = {2010},
}