Searched for: subject:"adaptation"
(1 - 10 of 10)
document
Korkiakoski, V.A. (author), Keller, C.U. (author), Doelman, N. (author), Kenworthy, M. (author), Otten, G. (author), Verhaegen, M.H.G. (author)
We present two complementary algorithms suitable for using focal-plane measurements to control a wavefront corrector with an extremely high-spatial resolution. The algorithms use linear approximations to iteratively minimize the aberrations seen by the focal-plane camera. The first algorithm, Fast & Furious (FF), uses a weak-aberration...
journal article 2014
document
Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N. (author), Fraanje, P.R. (author), Verhaegen, M.H.G. (author)
We study different possibilities to use adaptive optics (AO) and phase diversity (PD) together in a jointly optimized system. The potential of the joint system is demonstrated through numerical simulations. We find that the most significant benefits are obtained from the improved deconvolution of AO-corrected wavefronts and the additional...
journal article 2011
document
Fraanje, R. (author), Doelman, N. (author)
In recent years various researchers have proposed an optimal control approach for the rejection of turbulence-induced wavefront distortions in an AO system. The essential element in the design of an optimal controller is the choice for the turbulence model, which predicts the turbulence to compensate for the inherent delay in the AO control loop...
conference paper 2010
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Fraanje, P.R. (author), Rice, J. (author), Verhaegen, M. (author), Doelman, N. (author)
Efficient and optimal prediction of frozen flow turbulence using the complete observation history of the wavefront sensor is an important issue in adaptive optics for large ground-based telescopes. At least for the sake of error budgeting and algorithm performance, the evaluation of an accurate estimate of the optimal performance of a particular...
journal article 2010
document
Hinnen, K. (author), Verhaegen, M. (author), Doelman, N. (author)
Adaptive optics (AO) is used in ground-based astronomical telescopes to improve the resolution by counteracting the effects of atmospheric turbulence. Most AO systems are based on a simple control law that neglects the temporal evolution of the distortions introduced by the atmosphere. This paper presents a datadriven control design approach...
journal article 2008
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Hinnen, K. (author), Verhaegen, M.H.G. (author), Doelman, N. (author)
A recently proposed data-driven H2-optimal control approach is demonstrated on a laboratory setup. Most adaptive optics (AO) systems are based on a control law that neglects the temporal evolution of the wavefront. The proposed control approach is able to exploit the spatiotemporal correlation in the wavefront without assuming any form of...
journal article 2007
document
Hinnen, K. (author), Verhaegen, M. (author), Doelman, N. (author)
Most adaptive optics systems (AO) are based on a simple control law that is unable to account for the temporal evolution of the wavefront. In this paper, a recently proposed data-driven H2-optimal control approach is demonstrated on an AO laboratory setup. The proposed control approach does not assume any form of decoupling and can therefore...
conference paper 2006
document
Hinnen, K. (author), Doelman, N. (author), Verhaegen, M. (author)
The problem of finding the closed-loop optimal controller is formulated in an H2-optimal control framework. This provides a natural way to account for the fact that in many AO systems the wavefront phase cannot be measured directly. Given a multi-variable disturbance model of both wavefront slopes and wavefront phases,3 this provides a general...
conference paper 2005
document
Hinnen, K. (author), Verhaegen, M. (author), Doelman, N. (author)
Even though the wavefront distortion introduced by atmospheric turbulence is a dynamic process, its temporal evolution is usually neglected in the adaptive optics (AO) control design. Most AO control systems consider only the spatial correlation in a separate wavefront reconstruction step. By accounting for the temporal evolution of the...
conference paper 2005
document
Doelman, N.J. (author), Hinnen, K.J.G. (author), Stoffelen, F.J.G. (author), Verhaegen, M.H. (author)
An Adaptive Optics (AO) system for astronomy is analysed from a control point of view. The focus is put on the temporal error. The AO controller is identified as a feedback regulator system, operating in closed-loop with the aim of rejecting wavefront disturbances. Limitations on the performance of feedback regulator systems are discussed. The...
conference paper 2004
Searched for: subject:"adaptation"
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