40 research outputs found

    Identification and control of parallel robots in the state space with a remote laboratory

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    [EN] This article presents a remote laboratory to carry out identification and control experiments of two real parallel robots over the Internet. The remote laboratory has a client-server architecture. The client is a Java control interface that allows the user to command experiments and visualize the results in the form of graphs and live feed of the robots. The server is an industrial computer that controls both robots through a dSPACE 1103 control board programmed with Matlab/Simulink, and also runs Jimserver and other programs that allow the users to reserve and safely use the robots. The article describes and illustrates various laboratory practices and experiments that can be carried out with the presented remote laboratory, such as the identification of the linearized state-space model of the robots, the design of integral regulators with state feedback, or study how singularities of parallel robots decrease their controllability.[ES] En este artículo se presenta un laboratorio remoto para realizar prácticas de identificación y control de dos robots paralelos reales mediante Internet. El laboratorio remoto tiene una arquitectura cliente-servidor. El cliente es una interfaz de control Java que permite comandar experimentos y visualizar los resultados en forma de gráficas y de imágenes de video en tiempo real de los robots. Por su parte, el servidor es un computador industrial que controla a los robots mediante una tarjeta de control dSPACE 1103 programada con Matlab/Simulink, y además ejecuta Jimserver y otros programas de gestión que permiten reservar y utilizar los robots de forma segura. El artículo describe e ilustra varias prácticas y experimentos que pueden realizarse con el laboratorio remoto presentado, como la identificación del modelo de estado linealizado de los robots, el diseño de reguladores integrales con realimentación del estado, o estudiar cómo las singularidades de los robots paralelos disminuyen su controlabilidad.Trabajo financiado por el Centro de Inteligencia Digital de Alicante mediante el proyecto “Hacia la formación práctica ubicua y digital en robótica mediante laboratorios remotos”.Peidró, A.; Payá, L.; Ballesta, M.; Gil, A.; Reinoso, O. (2024). Identificación y control de robots paralelos en el espacio de estados con un laboratorio remoto. Revista Iberoamericana de Automática e Informática industrial. 21(2):180-191. https://doi.org/10.4995/riai.2024.2006518019121

    Generación de data sets simulando diferentes tipos de cámaras en entornos virtuales

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    [Resumen] En este artículo se presenta una plataforma para crear diferentes tipos de data sets a partir de entornos virtuales. Estos data sets contienen información sobre la apariencia visual del entorno y sobre la distancia desde algunas posiciones de referencia hasta todos los objetos. Los algoritmos diseñados para la creación de mapas y la localización de robots deben ser probados y testados con diferentes conjuntos de imágenes para validarlos. Esto puede llevarse a cabo utilizando imágenes reales, sin embargo, un cambio en los parámetros del sistema de visión supondría su sustitución y se tendrían que volver a capturar nuevos data sets. Esto supone un alto coste y frena el avance en las primeras fases del desarrollo. El objetivo de este trabajo es desarrollar una herramienta versátil que permita generar data sets para testar eficientemente estos algoritmos. Otra ventaja de esta plataforma es que pueden generarse imágenes desde cualquier posición del entorno y con cualquier rotación. Además, las imágenes generadas no tienen ruido; lo que permite llevar a cabo una prueba preliminar en condiciones ideales. El entorno virtual se puede crear y modificar fácilmente. Por último, la plataforma permite realizar otras tareas avanzadas utilizando las imágenes generadas y el entorno virtual.Este trabajo ha sido financiado por el gobierno español a través del proyecto DPI2013-41557-P: “Navegación de Robots en Entornos Dinámicos Mediante Mapas Compactos con Información Visual de Apariencia Global”. Y por la Generalitat Valenciana (GVa) a través del proyecto GV/2015/031: “Creación de mapas topológicos a partir de la apariencia global de un conjunto de escenas.”Generalitat Valenciana; GV/2015/031https://doi.org/10.17979/spudc.978849749808

    Changes in Access to Health Services of the Immigrant and Native-Born Population in Spain in the Context of Economic Crisis

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    Aim: To analyze changes in access to health care and its determinants in the immigrant and native-born populations in Spain, before and during the economic crisis. Methods: Comparative analysis of two iterations of the Spanish National Health Survey (2006 and 2012). Outcome variables were: unmet need and use of different healthcare levels; explanatory variables: need, predisposing and enabling factors. Multivariate models were performed (1) to compare outcome variables in each group between years, (2) to compare outcome variables between both groups within each year, and (3) to determine the factors associated with health service use for each group and year. Results: unmet healthcare needs decreased in 2012 compared to 2006; the use of health services remained constant, with some changes worth highlighting, such as the decline in general practitioner visits among autochthons and a narrowed gap in specialist visits between the two populations. The factors associated with health service use in 2006 remained constant in 2012. Conclusion: Access to healthcare did not worsen, possibly due to the fact that, until 2012, the national health system may have cushioned the deterioration of social determinants as a consequence of the financial crisis. Further studies are necessary to evaluate the effects of health policy responses to the crisis after 2012

    Localización de robots móviles con 4 GDL mediante visión omnidireccional

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    [Resumen] La localización de robots, junto a la creación de mapas y planificación, es una tarea fundamental que permite la navegación autónoma de estos dispositivos en un entorno desconocido. En este trabajo se presenta un método para calcular la transformación entre dos poses del robot que se desplaza en un entorno en el que pueden darse cambios en la altura. Estos robots están provistos de un sistema omnidireccional que les permite obtener puntos característicos del entorno. A partir de estos puntos, aplicamos el método que se describe en este trabajo, para obtener la localización del robot salvo un factor de escala sin tener conocimiento previo de la escena.Generalitat Valenciana; AICO/2015/021https://doi.org/10.17979/spudc.978849749808

    Exploring the presence of five rare earth elements in vineyard soils on different lithologies: Campo de Calatrava, Spain

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    The aim of the work described here was to understand the pedogeochemical signature of five rare earth elements (REEs; Ce, Nd, La, Y, and Sc) in vineyard soils in Campo de Calatrava (a unique territory with calcareous, volcanic and metamorphic rocks). The mean contents in surface horizons of Ce, Nd, La, Y, and Sc were 65.7, 32.0, 35.5, 18.8, and 13.9 mg·kg–1, respectively. In subsurface horizons the contents were Ce 62.8, Nd 31.1, La 35.7, Y 17.9, and Sc 14.4 mg·kg–1 . The results show that mean contents of REEs in the area under investigation are in the order Ce > Nd > La > Y > Sc. Ce has a very high range, with a value close to 150 mg·kg–1 . On the other hand, concentrations of Ce, Nd, Y, and Sc are higher in soils on volcanic material than in soils on nonvolcanic material, while only La values are lower in soils on volcanic rocks. The distributional maps of REEs in surface and subsurface horizons suggest that parent material and pedogenesis such as argillization and calcium carbonate accumulation are more important factors than the use of REE-based fertilizers, except in certain exceptional cases (consistent with a possible specific human impact after continuous fertilization

    Estimation of Visual Maps with a Robot Network Equipped with Vision Sensors

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    In this paper we present an approach to the Simultaneous Localization and Mapping (SLAM) problem using a team of autonomous vehicles equipped with vision sensors. The SLAM problem considers the case in which a mobile robot is equipped with a particular sensor, moves along the environment, obtains measurements with its sensors and uses them to construct a model of the space where it evolves. In this paper we focus on the case where several robots, each equipped with its own sensor, are distributed in a network and view the space from different vantage points. In particular, each robot is equipped with a stereo camera that allow the robots to extract visual landmarks and obtain relative measurements to them. We propose an algorithm that uses the measurements obtained by the robots to build a single accurate map of the environment. The map is represented by the three-dimensional position of the visual landmarks. In addition, we consider that each landmark is accompanied by a visual descriptor that encodes its visual appearance. The solution is based on a Rao-Blackwellized particle filter that estimates the paths of the robots and the position of the visual landmarks. The validity of our proposal is demonstrated by means of experiments with a team of real robots in a office-like indoor environment

    Trends in socioeconomic inequalities in mortality in small areas of 33 Spanish cities

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    Background: In Spain, several ecological studies have analyzed trends in socioeconomic inequalities in mortality from all causes in urban areas over time. However, the results of these studies are quite heterogeneous finding, in general, that inequalities decreased, or remained stable. Therefore, the objectives of this study are: (1) to identify trends in geographical inequalities in all-cause mortality in the census tracts of 33 Spanish cities between the two periods 1996–1998 and 2005–2007; (2) to analyse trends in the relationship between these geographical inequalities and socioeconomic deprivation; and (3) to obtain an overall measure which summarises the relationship found in each one of the cities and to analyse its variation over time. Methods: Ecological study of trends with 2 cross-sectional cuts, corresponding to two periods of analysis: 1996–1998 and 2005–2007. Units of analysis were census tracts of the 33 Spanish cities. A deprivation index calculated for each census tracts in all cities was included as a covariate. A Bayesian hierarchical model was used to estimate smoothed Standardized Mortality Ratios (sSMR) by each census tract and period. The geographical distribution of these sSMR was represented using maps of septiles. In addition, two different Bayesian hierarchical models were used to measure the association between all-cause mortality and the deprivation index in each city and period, and by sex: (1) including the association as a fixed effect for each city; (2) including the association as random effects. In both models the data spatial structure can be controlled within each city. The association in each city was measured using relative risks (RR) and their 95 % credible intervals (95 % CI). Results: For most cities and in both sexes, mortality rates decline over time. For women, the mortality and deprivation patterns are similar in the first period, while in the second they are different for most cities. For men, RRs remain stable over time in 29 cities, in 3 diminish and in 1 increase. For women, in 30 cities, a non-significant change over time in RR is observed. However, in 4 cities RR diminishes. In overall terms, inequalities decrease (with a probability of 0.9) in both men (RR = 1.13, 95 % CI = 1.12–1.15 in the 1st period; RR = 1.11, 95 % CI = 1.09–1.13 in the 2nd period) and women (RR = 1.07, 95 % CI = 1.05–1.08 in the 1st period; RR = 1.04, 95 % CI = 1.02–1.06 in the 2nd period). Conclusions: In the future, it is important to conduct further trend studies, allowing to monitoring trends in socioeconomic inequalities in mortality and to identify (among other things) temporal factors that may influence these inequalities.This article was partially funded by Plan Nacional de I + D + I 2008–2011 and Instituto de Salud Carlos III (ISCIII) –Subdirección General de Evaluación y Fomento de la Investigación- (Award numbers: PI081488, PI081978, PI080367, PI08/1017, PI080330, P08/0142, PI081785, PI080662, PI081713, PI081058, PI081340, PI080803, PI126/08), Fundación Canaria de Investigación Sanitaria FUNCIS 84/07 and by CIBER Epidemiología y Salud Pública (CIBERESP)
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