Person: Álvarez Fernández-Balbuena, Antonio
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First Name
Antonio
Last Name
Álvarez Fernández-Balbuena
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
10 results
Search Results
Now showing 1 - 10 of 10
Item Mathematical Model Applied To Improve The Natural Lighting Design(International Journal of Sustainable Development and Planning, 2017) García Fernández, Berta; Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, AntonioDaylighting must be considered as the greenest way to illuminate any space and one of the most important architectural design challenges and opportunities. Human life is strongly influenced by natural lighting, and nowadays we have to add to this factor the importance of energy conservation and pollution reduction objectives. The development of hollow light guides offers people the advantages of natural lighting and the benefits of reduced energy consumption systems, providing changes in architectural form of spaces where sunlight does not have direct access. Hollow Cylindrical Prismatic Light Guides (CPLGs) are transparent optical components able to transmit high diameter light beams in daylight buildings applications without relevant losses. The goal of this paper is to show a novel lighting design based on hollow prismatic light pipes, which let daylight to be introduced inside of buildings. An improved mathematical modelling to predict light transmission efficiency based on realistic software simulations and experimental models is presented.Item Improvement of driver night vision in foggy environments by structured light projection.(Heliyon, 2022) Quintana Benito, Jaime; Álvarez Fernández-Balbuena, Antonio; Martínez Antón, Juan Carlos; Vázquez Moliní, DanielNowadays, fog is still a natural phenomenon that hinders our ability to detect targets, particularly in the field of driving where accidents are increasing. In the literature we find different studies determining the range of visibility, improving the quality of an image, determining the characteristics of fog, etc. In this work we propose the possibility of using a structured lighting system, on which we project the light towards the target, limiting the field lighting. We have developed a scattering light propagation model to simulate and subsequently study the veil luminance, generated by backscattering, to predict the decrease in visibility. This simulation considers the type of fog, the relative orientation of various elements (observer, light source and targets). We have built a fog chamber to validate the experimental params of the described system. The results obtained from both the simulation and the experimental measurements demonstrate that it is possible to obtain a high contrast enhancement for viewing a target when illuminated as described. Clearly, this kind of lighting technology will improve the road safety in foggy night environments. The results of this work can also be extrapolated to any situation in which the visibility of an observer is compromised by the environment, such as heavy rain, smoke from fires, among others.Item Advanced daylighting evaluation applied to cultural heritage buildings and museums: Application to the cloister of Santa Maria El Paular(Renewable Energy, 2016) Mayorga Pinilla, Santiago; Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, Antonio; Hernández Raboso, Gabriel; Herráez, Juan Antonio; Azcutia, Marta; García Botella, ÁngelA method to evaluate the risk of using daylight in museums and cultural heritage exhibitions is presented along this study. Although daylight is an ecological and sustainable source of energy and sometimes also an intrinsic part of the artwork, the use of Natural lighting may cause damages in them due to the difficulty of controlling its variability. The developed method quantifies the damage produced to the artworks by daylight compared to artificial light taking into account the level of radiation and its spectral distribution in space and time by comparison with the damage caused by an Illuminant A (Global Risk Factor). The method, applied to the permanent paintings exhibition in the cloister of the fifteenth century of the Monastery of Santa Maria de El Paular, certifies that the control and exploitation of Natural Light should consider an optimal balance between exposure and damage.Item Efficient and sustainable energy lighting solutions(Proceedings of SPIE, 2019) García Botella, Ángel; Vázquez Moliní, Daniel; García Fernández, Berta; Álvarez Fernández-Balbuena, AntonioThe electric lighting is responsible for 15% of the electricity consumption, the efficiency in this sector has a good progress in recent years, it can still improve more. Conventional energy sources are polluting and limited, so it is essential to use less aggressive energies with the environment. In lighting, this premise is being implemented in a cross-cutting manner, but in response to varied and sometimes contradictory interests. The development of lighting devices based on solar radiation is an inalienable objective, as is the use of artificial lighting sources that are clean with the environment. To achieve these two objectives, it is essential to know and study the design techniques of non-image optics. In the present work we present new systems design techniques and lighting elements: ray tracing optimization technique, light vector field technique. As well as its implementation and application in various areas of lighting: lighting in office buildings, libraries museums. We show that renewable energy strategy in the field of lighting not only produce energy save, also produce good effects in other aspects of human life like well-being, productivity and heritage conservation.Item Iluminar obras de arte mejorando la conservación. El proyecto Zeus(2015) Benítez, Anton J.; Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, AntonioLa iluminación de obras de arte se enfrenta al reto de resultar adecuada para la exhibición y de minimizar en lo posible los daños a la superficie y los materiales que las componen. En esta encrucijada, en la que la investigación es imprescindible tanto en tecnología como acerca de la recepción por parte del público, el proyecto Zeus trata de obtener una precisa información sobre el color de la obra, y trasladarla a un modelo de iluminación individualizado punto a punto, que permite simular condiciones precisas y compensar efectos indeseables del deterioro, minimizando la luz absorbida por la obra.Item Advances on geometric flux optical design method(Proceedings of SPIE, 2017) García Botella, Ángel; Álvarez Fernández-Balbuena, Antonio; Vázquez Moliní, DanielNonimaging optics is focused on the study of methods to design concentrators or illuminators systems. It can be included in the area of photometry and radiometry and it is governed by the laws of geometrical optics. The field vector method, which starts with the definition of the irradiance vector E, is one of the techniques used in nonimaging optics. Called “Geometrical flux vector” it has provide ideal designs. The main property of this model is, its ability to estimate how radiant energy is transferred by the optical system, from the concepts of field line, flux tube and pseudopotential surface, overcoming traditional raytrace methods. Nevertheless this model has been developed only at an academic level, where characteristic optical parameters are ideal not real and the studied geometries are simple. The main objective of the present paper is the application of the vector field method to the analysis and design of real concentration and illumination systems. We propose the development of a calculation tool for optical simulations by vector field, using algorithms based on Fermat`s principle, as an alternative to traditional tools for optical simulations by raytrace, based on reflection and refraction law. This new tool provides, first, traditional simulations results: efficiency, illuminance/irradiance calculations, angular distribution of light- with lower computation time, photometrical information needs about a few tens of field lines, in comparison with million rays needed nowadays. On the other hand the tool will provides new information as vector field maps produced by the system, composed by field lines and quasipotential surfaces. We show our first results with the vector field simulation tool.Item Light losses in hollow, prismatic light guides related to prim defects: a transmittance model(Chinese Optics Letters, 2015) García Fernández, Berta; Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, Antonio; García Botella, Ángel; Martínez Antón, Juan CarlosHollow, cylindrical, prismatic light guides (CPLGs) are optical components that, using total internal reflection (TIR), are able to transmit high-diameter light beams in daylight and artificial lighting applications without relevant losses. It is necessary to study the prism defects of their surfaces to quantify the behavior of these optical components. In this Letter, we analyze a CPLG made of a transparent dielectric material. Scanning electron microscopy (SEM) and the topographic optical profilometry by absorption in fluids (TOPAF) imaging technique are conducted to determine if there are defects in the corners of the prisms. A model for light guide transmittance that is dependent on prism defects is proposed. Finally, a simulation and an experimental study are carried out to check the validity of the proposed model.Item Energy optimization of a light projection system for buildings that virtually restores artworks(Digital Applications in Archaeology and Cultural Heritage, 2019) Vázquez Molini, Daniel; Álvarez Fernández-Balbuena, Antonio; Canabal Boutureira, Héctor Alfonso; Muro, Carmen; Durmus, D.; Davis, W.; Benítez Iglesias, Antonio Jesús; Mayorga Pinilla, SantiagoThe need to achieve energy efficiency standards in the lighting systems of buildings makes it necessary to optimize all aspects of them. Here, the development of a light projection system that achieves this goal by studying and modifying the spectral output, compared to conventional illumination, is described. A lighting system that estimates the reflectance characteristics of artwork and emits optimized lighting can reduce light absorption. A damage-minimizing point-by-point light projection system is developed using an optimization algorithm, to improve the appearance of the surfaces of artworks whose color has faded. In this case, a simulation of an aged oil painting was made by manipulating the original photograph, which was printed and to which the proposed system was applied. The results show that, when the aged printed image is illuminated with the optimized light source, it appears indistinguishable from the non-aged oil painting.Item Developments for lighting applications by using prismatic film(Proceedings of SPIE, 2019) García Fernández, Berta; Álvarez Fernández-Balbuena, Antonio; Vázquez Moliní, DanielPrismatic film offer advantages such as the possibility of transmit light effectively in lighting applications with the benefit of reducing energy consumption. This paper presents several developments based on their characteristics which allow direct light suitably in several fields as architecture, road and automotive lighting and signaling. A mathematical model is presented to provide a quantitative estimation of the influence of numerous factors that affect the transport of light in order to easily predict light extraction while avoiding heavy software calculations. The deformation produced in a prismatic film induced by changes in the curvature of the cylindrical guide is characterized by image analysis. This method shows the relationship between the curvature of the film, the deformation and the flux of transmitted light.Item Evolutionary optimization algorithms for nonimaging optical design(Proceedings of SPIE, 2019) García Botella, Ángel; Vázquez Moliní, Daniel; García Fernández, Berta; Álvarez Fernández-Balbuena, AntonioEvolutionary optimization algorithms have been recently introduced as nonimaging optics design techniques. Unlike optimization of imaging systems, non sequential ray tracing simulations and complex non centred systems design must be considered, adding complexity to the problem. The Merit Function (MF) is a key element in the automatic optimization algorithm, nevertheless the selection of each objective's weight, {wi}, inside merit function needs a previous trial and error process for each optimization. The problem then is to determine appropriate weights value for each objective. In this paper we propose a new Dynamic Merit Function, DMF, with variable weight factors {wi(n)}. The proposed algorithm, automatically adapts weight factors, during the evolution of the optimization process. This dynamic merit function avoids the previous trial and error procedure selecting the right merit function and provides better results than conventional merit functions (CMF). Also we analyse the Multistart optimization algorithm applied in the flowline nonimaging design technique.