4,133 research outputs found

    Probabilistic localization of gas emission areas with a mobile robot in indoor environments

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    This work deals with the problem of gas source localization by a mobile robot with gas-sensing capabilities. Particularly, we address the problem for the case of indoor environments, where the presence of obstacles and the possibly complex structure with multiple rooms, inlets and outlets provoke the chaotic dispersion of the gases. Under these challenging conditions, where traditional approaches based on tracking or mathematical modeling of the plume cannot be applied, we propose a two-stage methodology to split the search into coarse and fine localization. Focusing on the broad localization, we contribute with a novel approach to estimate, from a set of sparse observations, the likelihood of different regions in the environment to hold a gas source. Experiments demonstrate that our approach is suitable to locate gas emission sources.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    The Assessment of Land Degradation and Desertification in Mexico: Mapping Regional Trend Indicators with Satellite Data

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    Understanding the patterns of land degradation and desertification to develop mitigation strategies requires identification of methods for accurate and spatially explicit assessment and monitoring. Remote sensing data offer the possibility to develop strategies that outline degradation and desertification. The free access policy on satellite imagery enables a new pathway to measure, assess, and monitor land degradation using indicators derived from multispectral satellite data. This chapter seeks to explore a methodology for land degradation and desertification assessment and monitoring, based on freely available multispectral satellite data. The method identifies net primary productivity (NPP) and canopy cover (CC) as indicators of degradation. The trajectories of these indicators show patterns and trends over time. The methodological development presented here is intended to be a tool for regional landscape monitoring and assessment, enabling the formulation of corrective action plans. This methodology was tested in a semi-deciduous ecosystem in the southeast of Mexico

    Intramolecular [3+2] Cycloaddition of Fused Azolo-Azepanes from Azido Monosaccharides Derivatives

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    Síntesis de bicíclicos compuestos empleando epoxiamidas como material de partida. Obtención de tetrazolo azepanos con posible actividad biológica.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Three Realizations and Comparison of Hardware for Piezoresistive Tactile Sensors

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    Tactile sensors are basically arrays of force sensors that are intended to emulate the skin in applications such as assistive robotics. Local electronics are usually implemented to reduce errors and interference caused by long wires. Realizations based on standard microcontrollers, Programmable Systems on Chip (PSoCs) and Field Programmable Gate Arrays (FPGAs) have been proposed by the authors for the case of piezoresistive tactile sensors. The solution employing FPGAs is especially relevant since their performance is closer to that of Application Specific Integrated Circuits (ASICs) than that of the other devices. This paper presents an implementation of such an idea for a specific sensor. For the purpose of comparison, the circuitry based on the other devices is also made for the same sensor. This paper discusses the implementation issues, provides details regarding the design of the hardware based on the three devices and compares them.This work has been partially funded by the Spanish Government under contracts TEC2006-12376 and TEC2009-14446

    Estimación probabilística de áreas de emisión de gases con un robot móvil mediante la integracion temporal de observaciones de gas y viento

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    En este trabajo se aborda el uso de un robot m ovil para determinar la posición de una fuente de gas. Específicamente, nos centramos en el caso de entornos complejos, donde la presencia de múltiples habitaciones y obstáculos favorecen una dispersión caótica de los gases, lo cual dificulta en gran medida un modelado matemático del problema. Bajo estas condiciones, proponemos dividir la tarea de localización en dos fases: primero, determinar la zona del entorno donde se encuentra la fuente, y luego, determinar con precisión la localización de la misma dentro de la zona seleccionada. Centrándonos en la primera fase, proponemos el uso de un novedoso enfoque basado en un marco Bayesiano-probabilístico. Nuestro planteamiento se basa en la generación previa de un conjunto de mapas de dispersión de gas (empleando herramientas de simulación), atendiendo a las diferentes zonas del entorno y condiciones de viento. Comparando estos mapas con la información sensorial adquirida por el robot en cada instante de tiempo, derivamos la probabilidad de localización de la fuente, y guiamos el movimiento del robot hacia la dirección de máxima probabilidad. Para validar nuestro enfoque presentamos un total de 36 experimentos en los que un robot móvil localiza una fuente de gas en un entorno compuesto por múltiples habitaciones conexas.Este trabajo está financiado por el proyecto Español MINECO Retos AEROMAIN (DPI2014-5983-C2-1- R) así como por el proyecto AEROARMS (AErial RObotic system integrating multiple ARMS and advanced manipulation capabilities for inspection and maintenance), número de contrato 644271. La tesis de Alejandro Suárez está financiada por el Ministerio de Educación, Cultura y Deporte a través del programa FPU.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Evaluation of losses in a bidirectional wireless power transfer system for electric vehicles

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    Inductively power transfer systems are becoming increasingly popular in modern applications like electric vehicles. In order to make this technology attractive, its transfer efficiency must be considerably high. Most works in the literature define the efficiency of the wireless charger as the one associated to the inverter, the coupled coils and the compensation networks. Therefore, they usually omit the study of the losses occurring in other parts of the system such as in the secondary rectifier. This paper evaluates the losses in a complete wireless charger, built and designed to provide V2G functionalities. The experimental evaluation based on the waveform analysis is contrasted with a theoretical model, which relies on the non-idealities of the components. The evaluation reveals that measurement error greatly impact on the power losses derived by the two approachesUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    A Configurable Smart E-Nose for Spatio-Temporal Olfactory Analysis

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    This paper describes a novel electronic nose (enose) aimed at applications that require knowing not only the gas composition and concentration, but also its temporal and spatial evolution. This is done by capturing additional information related to the chemical substance such as the timestamp and geo-location of the measurements, as well as other physical magnitudes of the environment like temperature and humidity for correcting and interpreting the data. The device has been conceived following a modular architecture as a set of independent smart modules, which are interconnected and controlled through an I2C interface by a central processing unit. Each smart module can identify itself, store settings for autoconfiguration and perform signal pre-processing of the measured variables. Smart module types include: chemical sensors, communication interfaces, batteries, data storage, GPS, temperature and humidity.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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