Entwicklung intelligenter GNSS-basierten Landfahrzeug Lokalisierungssysteme

The usage of Global Navigation Satellites Systems (GNSS) for localisation purposes demands a permanent evaluation of the position information provided for the receiver, as well as a standardised GNSS-Receivers validation methodology and subsequently quality control procedures oriented to land vehicles within the ergodic hypothesis. The use of an independent reference system should provide enough information to validate the localisation system, but the lack of proper evaluation and procedures presents significant blind spots for future applications in both the GNSS-Receiver and the correspondent reference system. To solve these problems an approach based on artificial intelligence (AI) is presented. Also the development of an advanced filter technique for positioning estimation results in significant improvements of the reference system, even allowing a standalone GNSSdependent reference system when no independent systems are available. The presented developments are the bases for future intelligent GNSS-based localisation systems. The methodologies combine the advanced Particle Filter (PF) for positioning estimation with the newly developed Mahalanobis Ellipses Filter (MEF) methodology for accuracy-based data evaluation and the Artificial Neural Networks (ANN) models for both quantitative and qualitative validation. In this thesis the bases of the intelligent GNSS-based localisation system are presented and developed follows the BMW principle. In German the BMW principle stands for Beschreibungsmittel (means of description), Methode (methods) and Werkzeug (tool). The resulting system described along the thesis is applied and tested in a demonstrator tool, validating the developed methodologies in both software and hardware level. The proposed methodologies for the development of an intelligent GNSS-based localisation system are a substantial contribution for intelligent GNSS-based validation tools that will enable future safety-relevant applications, in field such as on-board uncertainty evaluation of vehicle localisation; advanced driver assistance systems; and GNSS-based vehicle localisation with intelligent maps for track selective enabled-localisation.Die Nutzung der globalen Navigationssatellitensysteme (GNSS) zu Lokalisierungszwecken erfordert eine ständige Auswertung der generierten Positionsinformationen sowie eine standardisierte Validierungsmethodik und anschließende Qualitätskontrollverfahren der GNSS-Empfänger. Die Verwendung eines unabhängigen Referenzsystems sollte genügend Informationen liefern, um das Lokalisierungssystem zu validieren, aber das Fehlen sowohl einer angemessenen Auswertung als auch entsprechender Verfahren stellen erhebliche Lücken für zukünftige Anwendungen sowohl dem Empfänger und der Referenz dar. Um diese Probleme zu lösen, wird ein Ansatz mit Künstlicher Intelligenz (KI) vorgestellt. Die Entwicklung KI-basierter Validierungstools sowie Filtertechniken zur Positionsbestimmung, um das Bezugssystem zu unterstützen, führt zu erheblichen Verbesserungen insofern, als dass ein GNSS-abhängiges Referenzsystem erstellt werden kann, wenn keine unabhängigen Referenzsysteme verfügbar sein sollten. Diese zusätzlichen Elemente sind die Grundlagen für zukünftige intelligente GNSSbasierte Lokalisierungssysteme. Die vorgestellten Methoden vereinen fortschrittliche Partikelfilter (PF) für die Positionsbestimmung mit der neuentwickelten Mahalanobis-Ellipsen-Filter (MEF)-Methodik für die genauigkeitsbasierte Datenauswertung, sowie einen Künstlichen-Neuronalen-Netze (KNN)-Ansatz für sowohl qualitative als auch quantitative Validierungstools. Im Rahmen des BMW-Prinzips (kurz für Beschreibungsmittel, Methoden undWerkzeuge) werden die Grundlagen für ein KI-basiertes System für GNSS-basierte Lokalisierungssysteme vorgestellt und im Rahmen dieser Arbeit entwickelt. Das sich ergebende intelligente GNSS-basierte Lokalisierungssystem wird in einem Demonstrator-Werkzeug angewendet, um das entwickelte System auf der Software- und Hardware-Ebene zu validieren. Abschließend wird eine Risikoanalyse des Demonstrators präsentiert. Diese Methoden zur Entwicklung eines intelligenten GNSS-basierten Lokalisierungssystems werden zukünftige sicherheitsrelevante Anwendungen in Bereichen wie Bordunsicherheitsermittlung in der Fahrzeuglokalisierung, Fahrassistenzsysteme und GNSSbasierte Fahrzeugortung mit intelligenten Karten für eine spurselektive Lokalisierung ermöglichen

High temperature fixed points: investigation of influence parameters on the temperature uncertainty by thermal modelling

En el campo del calibrado térmico, la determinación de puntos fijos de fusión de materiales eutécticos a alta temperatura es muy importante, debido a la dificultad para realizar medidas experimentales a altas temperaturas, el modelado térmico es una herramienta esencial para comprender las fuentes de incertidumbre en la obtención de estos puntos fijos. La diferencia entre la temperatura medida con el termómetro y la temperatura de la interfase líquido-sólido es causada por varios factores: Las pérdidas de calor al entorno, la resistencia térmica del metal y de las paredes del crisol, la distribución de temperatura en el horno, el diseño del crisol y del horno y la temperatura nominal del punto fijo. Como resultado de este trabajo, se ha evaluado la influencia de grietas y poros en aleaciones eutécticas con defectos de formación, se han calculado las incertidumbres asociadas a los valores de la emisividad y la conductividad térmica del grafito y se ha estimado tanto la influencia de la longitud del crisol y el espesor de sus paredes como el uso de hornos y perfiles de temperatura diferentes.Departamento de Ingeniería Energética y Fluidodinámic

Developing new paradigms for quantum measurements

L'abstract è presente nell'allegato / the abstract is in the attachmen

Experiments and Modelling of Automotive Turbochargers under Unsteady Conditions

The current global scenario, in which an ever increasing population with an ever growing transportation needs is coupled with a reduction in the fossil fuel production and increasing human-made pollution derived problems, leads automotive engine manufacturers to constant struggles for fuel consumption and emission reductions while keeping engine performance. One-dimensional simulation codes have become a key tool towards these objectives, but require continued accuracy refinements. Phenomena that were previously thought of a limited importance and could be extremely easily modelled now require the development of new methods to be accounted for. Among these phenomena are the turbocharger mechanical losses and the turbine behaviour under highly pulsating boundary conditions. This work is focused on the improvement of current one-dimensional models, for both mechanical losses prediction and high frequency pulsating flow turbine performance. After reviewing the state-of-the-art in experimental measurement and fast simulation of automotive turbochargers, this work presents first a experimental study of several turbochargers working under both steady-state and unsteady operating conditions, focusing on the general performance of the turbine and the losses in the power transmission between it and the compressor, even including internal pressure measurements in one of the tested units. All the measurements are corrected due to heat transfer, getting the purely adiabatic behaviour. Furthermore, a CFD simulation campaign of a radial turbine has been performed, thus obtaining a detailed description of its internal behaviour under highly pulsating flow. In the light of both the experimental and CFD-simulated results, a quasi-steady mechanical losses and a quasi-bidimensional turbine model have been developed. Both models have been validated using all the experimental and simulated data, proving a prediction accuracy improvements from the results of previous methods. The mechanical losses model offers a clear advantage over the usual practice of using a constant mechanical efficiency value for correcting the manufacturer’s turbocharger map, whereas the turbine model has demonstrated potential for turbine map extrapolation and has improved the instantaneous results over classic onedimensional turbine volute models for frequencies higher than 1000 Hz. Both models have been developed trying to keep a reduced computational cost, ensuring to exploit the specific characteristics of the processors where they are going to be run.García-Cuevas González, LM. (2014). Experiments and Modelling of Automotive Turbochargers under Unsteady Conditions [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48458TESI

Estudo teórico e experimental da aplicação de meios porosos cerâmicos em LHP e CPL

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduaçao em Engenharia Mecânica, Florianópolis, 2010O controle térmico na indústria eletrônica tem crescido em importância devido à contínua diminuição de tamanho e ao aumento na potência dos componentes. Nestas aplicações, buscam-se dispositivos eficientes de transferência de calor, capazes de transferir grandes cargas de calor com uma diferença mínima de temperatura. Neste contexto, os tubos de calor (Heat Pipes - HPs), os tubos de calor em forma de circuito (Loop Heat Pipes - LHPs) e as bombas capilares (Capillary Pumping Loops - CPLs) são alternativas confiáveis e viáveis para a dissipação de calor. Os evaporadores capilares da maioria dos LHPs e CPLs utilizam meios porosos feitos de metal ou de plástico. Neste trabalho, um meio poroso cerâmico é proposto para aplicações em LHPs e CPLs. O desempenho do meio poroso cerâmico como evaporador capilar é analisado teórica e experimentalmente. Primeiramente, é feita uma análise teórica de transferência de calor e de massa de um evaporador capilar plano com uma estrutura porosa formada por uma ou duas camadas com propriedades diferentes. O meio poroso tem formato de um disco e é instalado entre os canais de líquido e de vapor. Um fluxo de calor externo é aplicado à superfície superior da estrutura porosa onde ocorre a evaporação do fluido de trabalho. A transferência de calor e de massa é modelada usando as equações macroscópicas de conservação da energia e da massa. O fluido é assumido incompressível, prevalece o equilíbrio térmico local e a Lei de Darcy é usada para modelar o fluxo viscoso dentro do meio poroso. Os modelos desenvolvidos permitem verificar o efeito das variáveis de projeto no desempenho do evaporador capilar tais como fluidos de trabalho, dimensões, permeabilidade, raio médio de poros e condutividade térmica do meio poroso. Para as análises experimentais, testes de desempenho de dois LHPs, um utilizando acetona e o outro água como fluidos de trabalho, foram realizados para potências de até 25 W. Além disso, testes de desempenho de um CPL usando água foram realizados para potências de até 30 W. O meio poroso cerâmico utilizado possui 50% de porosidade, distribuição de raio de poro entre 1 e 3E-6 m e uma permeabilidade de 1,5 E-14 m2. Considerando uma temperatura de operação limite de 100 °C e regime permanente, os LHPs foram capazes de transferir até 15 W para água e 25 W para acetona, enquanto que o CPL foi capaz de transferir até 30 W. Apesar do bom desempenho dos sistemas de bombeamento capilar avaliados, observou-se que mais pesquisas ainda são necessárias, buscando otimizar as propriedades termofísicas do meio poroso cerâmico e melhorar o projeto dos LHPs e do CPL

Development of a traceability route for areal surface texture measurements

Modern manufacturing industry is beginning to benefit from the ability to control the three dimensional, or areal, structure of a surface. To underpin areal surface manufacturing, a traceable measurement infrastructure is necessary. In this thesis a practical realisation of areal surface traceability is presented, which includes the development of: a primary in-strument, methodologies for using the primary instrument to calibrate material measure-ment standards used as standard transfer artefacts, and the process of transferring this traceability to industrial users of stylus and optical instruments. The design of the primary instrument and its complex measurement uncertainty model are described, including detailed analysis of the input parameters of the uncertainty model and their effect on the co-ordinate measurements of the instrument. The development of the process of transferring the areal traceability to industrial users lead to a set of metrological characteristics applicable to all areal surface topography measuring instruments. The set of metrological characteristics, now included into international stand-ards, comprise of: measurement noise, flatness deviation, amplification, linearity and squareness, and resolution. Despite the differences in operation of the various types of in-strument, the idea behind this set of metrological characteristics is based on the fact that these instruments produce three dimensional data sets of points, which is a new approach in the field. Metrological characteristics are quantities that can be measured directly, gener-ally using calibrated material measures. The development of standard methodologies for calibrating the metrological characteristics, and the explicit relationship between the metro-logical characteristics and the measurement uncertainty associated with the co-ordinate measurements provided by the instrument is presented. Many of the techniques described in this thesis are now being discussed for inclusion into international standards

Development and validation of novel and quantitative MRI methods for cancer evaluation

Quantitative imaging biomarkers (QIB) offer the opportunity to further the evaluation of cancer at presentation as well as predict response to anti-cancer therapies before and early during treatment with the ultimate goal of truly personalised medical care and the mitigation of futile, often detrimental, therapy. Few QIBs are successfully translated into clinical practice and there is increasing recognition that rigorous methodologies and standardisation of research pipelines and techniques are required to move a theoretically useful biomarker into the clinic. To this end, I have aimed to give an overview of what I believe to be some of key elements within the research field beginning with the concept of imaging biomarkers, introducing concepts in development and validation, before providing a summary of the current and future utility of a range of quantitative MR imaging biomarkers techniques within the oncological imaging field. The original, prospective, research moves from the technical and analytical validation of a novel QIB use (T1 mapping in cancer), first in vivo qualification of this biomarker in cancer patient response assessment and prediction (sarcoma and breast cancer as well as prostate cancer separately), and then moving on to application of more established QIBs in cancer evaluation (R2*/BOLD imaging in head and neck cancer) as well as how existing MR data can be post-processed to improved cancer evaluation (further metrics derived from diffusion weighted imaging in head and neck cancer and textural analysis of existing clinical MR images utility in prostate cancer detection)

Photogrammetry as a surveying thechnique apllied to heritage constructions recording - avantages and limitations

Dissertação de Mestrado Integrado em Arquitetura, com a especialização em Arquitetura apresentada na Faculdade de Arquitetura da Universidade de Lisboa para obtenção do grau de Mestre.A presente dissertação tem por objectivo investigar e evidenciar as vantagens da aplicação da fotogrametria, e possíveis integrações com outros métodos de levantamento, como seja o varrimento laser terrestre, posicionamento por GPS, entre outros, para realizar levantamentos de construções patrimoniais ou eruditas e a respectiva produção de documentação base para viabilizar intervenções de conservação, restauro ou reabilitação. A motivação para a investigação advém da aplicação flexível, versátil, simples, acessível, e baixo-custo da fotogrametria em projectos de levantamento pequenos ou extensos. Tenciona-se igualmente colmatar as desvantagens tradicionais da fotogrametria, nomeadamente a transição entre espaços interiores e exteriores, e registo de espaços estreitos, de difícil acesso, e de geometrias complexas, num único projecto de documentação. Pretende-se ultrapassar estas dificuldades através da utilização máxima das potencialidades da fotogrametria com o uso de imagens olho de peixe e apenas como último recurso utilizar instrumentos complementares. No caso de estudo principal, o Castelo do Convento de Cristo, demonstra-se a aplicação dos métodos investigados. Nos casos de estudo secundários abordam-se problemas parcelares, desde elementos decorativos até à totalidade do edificado: Convento dos Capuchos, em Sintra; Alcáçova e trecho de muralha do Castelo de Sesimbra; Igreja de Stº André, em Mafra; entre outros. Os casos auxiliaram na determinação de procedimentos a generalizar posteriormente. Por fim, propõem-se algoritmos que auxiliam na produção de documentação.ABSTRACT: The present dissertation aims to research and demonstrate the advantages of the application of photogrammetry, and its possible integrations with other methods, such as terrestrial laser scanning, GPS positioning, and among others, to perform surveys of heritage or erudite buildings and respective production of base documentation to enable interventions of conservation, restoration, or rehabilitation. The motivation for researching is due to the flexible, versatile, simple, affordable, and low-cost application of photogrammetry in small and extensive survey projects. It is also intended to overcome the traditional disadvantages of photogrammetry, such as the transition between interior and exterior spaces, and difficulty of recording narrow, hard-to-access, and complex geometric spaces, in a single project. It is intended to overcome such challenges by maximizing the potential uses of photogrammetry with the use of fisheye images and by using other survey instruments as a last resort. In the main case study, the Castle of the Convent of Christ, the application of the investigated methods is demonstrated. In the secondary case studies, partial problems are addressed, ranging from decorative elements to the entire building: Convento dos Capuchos, in Sintra; Citadel and section of a wall of the Castle of Sesimbra; Igreja de St André, in Mafra; among others; The case studies aided in determining general procedures. Finally, algorithms that accelerate the production of documentation are proposed.N/

Super Insulating Materials for energy efficient buildings: thermal performance and experimental uncertainty

In a global energy-saving policy, Super Insulating Materials (SIMs) represent an effective solution, especially in a world almost saturated with old buildings for which energy refurbishments are needed. Given their extremely low thermal conductivity, they allow reaching an excellent insulation level, with reduced thicknesses. Anyway, they are recent materials or at least recent insulation solutions for the building sector. And as all the new technologies, they bring with them some critical issues to be solved. For example, what is the accuracy of their available thermal conductivity, what are the criteria for their optimal laboratory characterisation, what are their actual thermal performances in situ and how long is their durability and what is their practical convenience still remain open questions. The aim of this research was to provide an answer to these questions, although sometimes in a preliminary way. Therefore, the thermal properties of SIMs (and in particular of the Vacuum Insulation Panels, since, between the SIMs they are the most performing and the most critical solution) were explored at different levels, from the material/panel scale to the building scale. SIMs are actually laboratory tested using traditional experimental apparatuses, such as the Heat Flow Meter (HFM) and the Guarded Hot Plate (GHP), and in accordance with as traditional standard, developed for the most common insulating material. Indeed, at the first stage of this research, the applicability of the current methodologies was extensively verified, with an in-depth analysis of the obtainable measurement uncertainties. The uncertainty assessment was performed in three different ways, to analyse the various scenarios that may occur: a theoretical standard based uncertainty evaluation, and both the Type A and Type B experimental uncertainty assessment. Once defined the best criteria for a proper evaluation of the SIMs thermal properties, they were experimentally characterised, considering the different parameters which could have some effects on their thermal behaviour (different thicknesses, average testing temperature, temperature difference, ageing conditions and so on). In practical applications of the VIPs, they must be assembled one to each other: innovatively, both the HFM and GHP apparatuses were also used for the evaluation of the linear thermal transmittance of the thermal bridges that occur in case of VIPs assemblies. The investigation performed at the material/panel level were then repeated at the component scale, to evaluate the variability and the measurement uncertainty of the linear thermal transmittance. The so defined thermal performances represented a reliable pool of input data for the dynamic hygrothermal simulations at the building scale. The goals were the evaluation of the energy efficiency of building insulated with SIMs and the prediction of the durability of these materials (considering different severities of the building envelope component boundary conditions). The outputs of the numerical simulations were then coupled with an economic analysis, to evaluate the convenience of VIP insulation, in terms of discounted pay-back period

Selected Papers from the 5th International Electronic Conference on Sensors and Applications

This Special Issue comprises selected papers from the proceedings of the 5th International Electronic Conference on Sensors and Applications, held on 15–30 November 2018, on sciforum.net, an online platform for hosting scholarly e-conferences and discussion groups. In this 5th edition of the electronic conference, contributors were invited to provide papers and presentations from the field of sensors and applications at large, resulting in a wide variety of excellent submissions and topic areas. Papers which attracted the most interest on the web or that provided a particularly innovative contribution were selected for publication in this collection. These peer-reviewed papers are published with the aim of rapid and wide dissemination of research results, developments, and applications. We hope this conference series will grow rapidly in the future and become recognized as a new way and venue by which to (electronically) present new developments related to the field of sensors and their applications