Thesis CONTROL DE PERTURBACIONES DE ALTA FRECUENCIA DE TIP Y TILT EN SISTEMAS ÓPTICOS USANDO FAST STEERING MIRROR
Date
2016
Authors
CASTRO ROMERO, MARIO ANDRES
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Abstract
´ ptica Adaptativa (AO) fue una t´ecnica concebida para mejorar la calidad de las im´agenes astron´omicas obtenidas por telescopios ´opticos, mediante la compensaci´on de las perturbaciones producidas por la turbulencia atmosf´erica. Con el desarrollo de la instru- mentaci´on asociada la AO permiti´o obtener im´agenes cuya calidad esta cerca del l´imite f´isico puesto por la difracci´on. Una vez que la AO logr´o con ´exito la compensaci´on de la turbulencia atmosf´erica, otros problemas ganaron importancia, siendo el m´as importante el problema de las vibraciones del sistema ´optico inducidas por diversos factores muchas veces dif´iciles de determinar. Estas vibraciones estructurales est´an presentes mayoritariamente en las aberraciones tip-tilt, lo que reduce la precisi´on en la adquisici´on de im´agenes. Por lo tanto , se hace necesario tomar acciones de control.Con este objetivo se desarrolla una demostraci´on de laboratorio de un sistema para la compensaci´on de los modos tip-tilt usando control en lazo cerrado, induciendo vibraci´on al sistema utilizando un motor exc´entrico de frecuencia controlable. Se mide la posici´on del Laser usando una c´amara CMOS, mientras que la acci´on de control es realizada por un espejo Fast Steering Mirror (FSM).
The Adaptive Optics (AO) technology was conceived for the improvement in the astronomicalimages adquired by the optical telescopes via the compensation of atmosphericalturbulence. With the development of the associated technology, the AO allowed us to obtainimages near the physical difraction limit. Once the AO achieved succesfully the compensationof atmospheric turbulence, other problems gain more importance, being the mostimportant the problem of the vibrations in the optical system, produced by a number offactors that most of the time are dicult to establish. These structural vibrations induceaberration mainly in tip-tilt modes that reduce the accuracy of the astronomical instrument.Therefore, control actions need to be taken.With this purpose we present a laboratory demonstration of vibration rejection of tiptiltmodes using closed-loop control, inducing vibration on the test bench via an eccentricmotor with controllable frequency, in order to simulate the structural vibrations mentionedabove. We measure the laser vibration and its tip-tilt aberration using a CMOS camera.The control action is carried out by a Fast Steering Mirror (FSM).
The Adaptive Optics (AO) technology was conceived for the improvement in the astronomicalimages adquired by the optical telescopes via the compensation of atmosphericalturbulence. With the development of the associated technology, the AO allowed us to obtainimages near the physical difraction limit. Once the AO achieved succesfully the compensationof atmospheric turbulence, other problems gain more importance, being the mostimportant the problem of the vibrations in the optical system, produced by a number offactors that most of the time are dicult to establish. These structural vibrations induceaberration mainly in tip-tilt modes that reduce the accuracy of the astronomical instrument.Therefore, control actions need to be taken.With this purpose we present a laboratory demonstration of vibration rejection of tiptiltmodes using closed-loop control, inducing vibration on the test bench via an eccentricmotor with controllable frequency, in order to simulate the structural vibrations mentionedabove. We measure the laser vibration and its tip-tilt aberration using a CMOS camera.The control action is carried out by a Fast Steering Mirror (FSM).
Description
Catalogado desde la version PDF de la tesis.
Keywords
ABERRACION TIP-TILT , CONTROL EN LAZO CERRADO , FAST STEERING MIRROR , OPTICA ADAPTATIVA
