Open AccessMitigation of vibrations in adaptive optics by minimization of closed-loop residuals
Author(s) -
Andrés Guesalaga,
Benoît Neichel,
Jared O’Neal,
Dani Guzmán
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.010676
Subject(s) - integrator , control theory (sociology) , adaptive optics , vibration , computer science , controller (irrigation) , open loop controller , tilt (camera) , vibration isolation , minification , optics , physics , closed loop , control engineering , mathematics , acoustics , engineering , bandwidth (computing) , artificial intelligence , geometry , control (management) , biology , programming language , computer network , agronomy
We describe a new technique to reduce tip and tilt vibrations via the design of adaptive optics controllers in a frequency framework. The method synthesizes controllers by minimizing an H2 norm of the tip and tilt residuals. In this approach, open loop slopes (pseudo-open-loop) are reconstructed from on-sky data and input into off-line simulations of the adaptive optics system. The proposed procedure executes a sequence of off-line closed-loop runs with increasing controller complexity and searches for the controller that minimizes the variance of residuals. Although the method avoids any identification of the vibration and turbulence models during the controller synthesis, the actual models are indirectly constructed as a by-product of the H2 norm minimization. The technique has been implemented on and tested with two operational instruments, namely Paranal's NACO and Gemini-South's GeMS, showing an effective rejection of the main vibrations in the loop and also improving the overall performance of the system over varying turbulence conditions. It is shown that a superior performance is obtained when compared to the standard integrator controller.