Sphere extreme AO control scheme: final performance assessment and on sky validation of the first auto-tuned LQG based operational system (Orale)

Abstract : The SPHERE (Spectro-Polarimetry High-contrast Exoplanet Research) instrument is an ESO project aiming at the direct detection of extra-solar planets. SPHERE has been successfully integrated and tested in Europe end 2013 and has been re-integrated at Paranal in Chile early 2014 for a first light at the beginning of May. The heart of the SPHERE instrument is its eXtreme Adaptive Optics (XAO) SAXO (SPHERE AO for eXoplanet Observation) subsystem that provides extremely high correction of turbulence and very accurate stabilization of images for coronagraphic purpose. However, SAXO, as well as the overall instrument, must also provide constant operability overnights, ensuring robustness and autonomy. An original control scheme has been developed to satisfy this challenging dichotomy. It includes in particular both an Optimized Modal Gain Integrator (OMGI) to control the Deformable Mirror (DM) and a Linear Quadratic Gaussian (LQG) control law to manage the tip-tilt (TT) mirror. LQG allows optimal estimation and prediction of turbulent angle of arrival but also of possible vibrations. A specific and unprecedented control scheme has been developed to continuously adapt and optimize LQG control ensuring a constant match to turbulence and vibrations characteristics. SPHERE is thus the first operational system implementing LQG, with automatic adjustment of its models. SAXO has demonstrated performance beyond expectations during tests in Europe, in spite of internal limitations. Very first results have been obtained on sky last May. We thus come back to SAXO control scheme, focusing in particular on the LQG based TT control and the various upgrades that have been made to enhance further the performance ensuring constant operability and robustness. We finally propose performance assessment based on in lab performance and first on sky results and discuss further possible improvements.
Type de document :
Communication dans un congrès
SPIE Astronomical Telescopes + Instrumentation, Adaptive Optics Systems IV, Jun 2014, Montreal, Canada. Proc. SPIE, 9148, pp.91480O, 2014, 〈10.1117/12.2052847〉
Liste complète des métadonnées

Littérature citée [18 références]  Voir  Masquer  Télécharger

https://hal-onera.archives-ouvertes.fr/hal-01069649
Contributeur : Véronique Soullier <>
Soumis le : lundi 29 septembre 2014 - 15:38:03
Dernière modification le : lundi 24 septembre 2018 - 16:04:03
Document(s) archivé(s) le : mardi 30 décembre 2014 - 11:35:34

Fichier

DOTA14050.1405516220.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Citation

C. Petit, J.F. Sauvage, T. Fusco, A. Sevin, M. Suarez, et al.. Sphere extreme AO control scheme: final performance assessment and on sky validation of the first auto-tuned LQG based operational system (Orale). SPIE Astronomical Telescopes + Instrumentation, Adaptive Optics Systems IV, Jun 2014, Montreal, Canada. Proc. SPIE, 9148, pp.91480O, 2014, 〈10.1117/12.2052847〉. 〈hal-01069649〉

Partager

Métriques

Consultations de la notice

1032

Téléchargements de fichiers

257