Searched for: author:"Verhaegen, M.H.G."
(1 - 20 of 65)

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Koning, R.F.F. (author), Verhaegen, M.H.G. (author), Ben Klaassens, J. (author), Uittenbogaart, J.R. (author)
journal article 2000
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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
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Koopman, J. (author), Jeltsema, D. (author), Verhaegen, M.H.G. (author)
A port-Hamiltonian formulation of the LuGre friction model is presented that can be used as a building block in the physical modelling of systems with friction. Based on the dissipation structure matrix of this port-Hamiltonian LuGre model, an alternative proof can be given for the passivity conditions that are known in the literature. As a...
journal article 2010
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Van Engelen, T. (author), Schuurmans, J. (author), Kanev, S. (author), Dong, J. (author), Verhaegen, M.H.G. (author), Hayashi, Y. (author)
Extreme environmental conditions as well as system failure are real-life phenomena. Especially offshore, extreme environmental conditions and system faults are to be dealt with in an effective way. The project Sustainable Control, a new approach to operate wind turbines (Agentschap NL, grant EOSLT02013) pro- vides the concepts for an integrated...
conference paper 2011
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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
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Antonello, J. (author), Verhaegen, M.H.G. (author), Fraanje, R. (author), Van Werkhoven, T. (author), Gerritsen, H.C. (author), Keller, C.U. (author)
Wavefront sensorless adaptive optics methodologies are widely considered in scanning fluorescence microscopy where direct wavefront sensing is challenging. In these methodologies, aberration correction is performed by sequentially changing the settings of the adaptive element until a predetermined image quality metric is optimized. An efficient...
journal article 2012
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Polo, A. (author), Haber, A. (author), Pereira, S.F. (author), Verhaegen, M.H.G. (author), Urbach, H.P. (author)
We carry out performance characterisation of a commercial push and pull deformable mirror with 48 actuators (Adaptica Srl). We present a detailed description of the system as well as a statistical approach on the identification of the mirror influence function. A new efficient control algorithm to induce the desired wavefront shape is also...
journal article 2012
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De Visser, C.C. (author), Verhaegen, M.H.G. (author)
This paper presents a new method for zonal wavefront reconstruction (WFR) with application to adaptive optics systems. This new method, indicated as Spline based ABerration REconstruction (SABRE), uses bivariate simplex B-spline basis functions to reconstruct the wavefront using local wavefront slope measurements. The SABRE enables WFR on...
journal article 2012
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Verstraete, H.R.G.W. (author), Verhaegen, M.H.G. (author), Kalkman, J. (author)
In scanning microscopy and optical coherence tomography, aberrations of the wave-front cause a loss in intensity and resolution. Intensity and resolution are quantified using Fresnel propagation, Fraunhofer diffraction, and the calculation of overlap integrals.
conference paper 2013
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Oldenbeuving, R.M. (author), Song, H. (author), Schitter, G. (author), Verhaegen, M.H.G. (author), Klein, E.J. (author), Lee, C.J. (author), Offerhaus, H.L. (author), Boller, K.J. (author)
A novel and simple approach to optical wavelength measurement is presented in this paper. The working principle is demonstrated using a tunable waveguide micro ring resonator and single photodiode. The initial calibration is done with a set of known wavelengths and resonator tunings. The combined spectral sensitivity function of the resonator...
journal article 2013
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Haber, A. (author), Polo, A. (author), Ravensbergen, S. (author), Urbach, H.P. (author), Verhaegen, M.H.G. (author)
Using the subspace identification technique, we identify a finite dimensional, dynamical model of a recently developed prototype of a thermally actuated deformable mirror (TADM). The main advantage of the identified model over the models described by partial differential equations is its low complexity and low dimensionality. Consequently, the...
journal article 2013
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Smith, C.S. (author), Marinica, R.M. (author), Den Dekker, A.J. (author), Verhaegen, M.H.G. (author), Korkiakoski, V. (author), Keller, C.U. (author), Doelman, N. (author)
We propose an efficient approximation to the nonlinear phase diversity (PD) method for wavefront reconstruction and correction from intensity measurements with potential of being used in real-time applications. The new iterative linear phase diversity (ILPD) method assumes that the residual phase aberration is small and makes use of a first...
journal article 2013
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Qiu, Y. (author), Van Gijzen, M.B. (author), Van Winderden, J.W. (author), Verhaegen, M.H.G. (author)
This paper presents a class of preconditioners for sparse systems arising from discretized partial differential equations (PDEs). In this class of preconditioners, we exploit the multilevel sequentially semiseparable (MSSS) structure of the system matrix. The off-diagonal blocks of MSSS matrices are of low-rank, which enables fast computations...
conference paper 2013
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Hansson, A (author), Verhaegen, M.H.G. (author)
conference paper 2014
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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
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Yoo, H.W. (author), Royen, M.E. (author), van Cappellen, W.A. (author), Houtsmuller, A.B. (author), Verhaegen, M.H.G. (author), Schitter, G. (author)
Mismatch between the refractive indexes of immersion media and glass coverslips introduces spherical aberrations in microscopes especially for high numerical aperture objectives. This contribution demonstrates an automated adjustment of the coverslip correction collar in scanning confocal microscopy to compensate for spherical aberrations due to...
journal article 2014
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Gong, H. (author), Pozzi, P. (author), Soloviev, O.A. (author), Verhaegen, M.H.G. (author), Vdovine, G.V. (author)
We investigate the possibility of interferometric optical field sensor with DMD forming a series of sampling interferometers in the pupil of an optical system. Our preliminary experiment validates the feasibility of our approach for the field reconstruction in the case of coherent field. We believe that this approach can be extended to sensing...
conference paper 2015
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Yu, C. (author), Verhaegen, M.H.G. (author)
This paper studies the local identification of large-scale homogeneous systems<br/>with general network topologies. The considered local system identification problem involves unmeasurable signals between neighboring subsystems. Compared with our previous work in Yu et al. (2014) which solves the local identification of 1D homogeneous systems,...
conference paper 2015
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Vdovine, G.V. (author), Gong, H. (author), Soloviev, O.A. (author), Pozzi, P. (author), Verhaegen, M.H.G. (author)
We have experimentally demonstrated a lensless coherent microscope based on direct registration of the complex optical field by sampling the pupil with a sequence of two-point interferometers formed by a digital micromirror device. Complete registration of the complex amplitude in the pupil of the imaging system, without any reference beam,...
journal article 2015
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Yu, C. (author), Verhaegen, M.H.G. (author), Hansson, A (author)
This paper studies the local subspace identification of 1D homogeneous networked systems. The main challenge lies at the unmeasurable interconnection signals between neighboring subsystems. Since there are many unknown inputs to the concerned local system, the corresponding identification problem is semi-blind. To cope with this problem, a...
conference paper 2015
Searched for: author:"Verhaegen, M.H.G."
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