Fractional loop delays in adaptive optics modeling and control.
J Opt Soc Am A Opt Image Sci Vis
; 41(1): 111-126, 2024 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-38175136
ABSTRACT
This paper revisits the problem of optimal (minimum variance) control for adaptive optics (AO) systems when measurement and command applications are asynchronous, resulting in a non-integer servo loop delay. When not properly accounted for, such fractional delays may severely degrade the AO performance, especially in the presence of high-frequency vibrations. We present evidence of this performance degradation thanks to in-lab experimental measurements on the Gran Telescopio Canarias Adaptive Optics (GTCAO) system controlled with standard suboptimal linear quadratic Gaussian (LQG) controllers. A constructive, easy to implement LQG control design is then proposed and validated in a simulation for vibrations affecting the tip-tilt modes. Our methodology is very interesting because it allows a performance assessment for any linear controller in terms of variance, rejection transfer functions, power spectral densities, and stability margins. We also show how the continuous-time disturbance model can be derived from standard discrete-time disturbance data-based modeling.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Opt Soc Am A Opt Image Sci Vis
Assunto da revista:
OFTALMOLOGIA
Ano de publicação:
2024
Tipo de documento:
Article