Evaluating a human-robot interface for exploration missions

The research reported in this paper concerns the design, implementation, and experimental evaluation of a Human-Robot Interface for stationary remote operators, implemented for a PC computer. The GUI design and functionality is described. An Autonomy Management Model has been implemented and explained. We have conducted user evaluation, making two set of experiments, that will be described and the resulting data analyzed. The conclusions give an insight on the most important usability concerns, regarding the operator situational awareness. The scalability of the interface is also experimentally studied

Use of portable devices and confocal Raman spectrometers at different wavelength to obtain the spectral information of the main organic components in tomatoes (Solanum Lycopersicum) fruits

Tomato (Solanum lycopersicum) fruit samples, in two ripening stages, ripe (red) and unripe (green), collected from a cultivar in the North of Spain (Barrika, Basque Country), were analyzed directly, without any sample pretreatment, with two different Raman instruments (portable spectrometer coupled to a micro-videocamera and a confocal Raman microscope), using two different laser excitation wavelengths (514 and 785 nm, only for the confocal microscope). The combined use of these laser excitation wavelengths allows obtaining, in a short period of time, the maximum spectral information about the main organic compounds present in this fruit. The major identified components of unripe tomatoes were cutin and cuticular waxes. On the other hand, the main components on ripe tomatoes were carotenes, polyphenoles and polysaccharides. Among the carotenes, it was possible to distinguish the presence of lycopene from b-carotene with the help of both excitation wavelengths, but specially using the 514 nm one, which revealed specific overtones and combination tones of this type of carotene.This work has been financially supported by Research Project S-PE11-UN128 of the Basque Country government. Technical and support provided by SGIker (UPV/EHU, MICINN, GV/EJ, ESF) is gratefully acknowledged

Computation of the optimal relative pose between overlapping grid maps through discrepancy minimization

Grid maps are a common environment representation in mobile robotics. Many Simultaneous Localization and Mapping (SLAM) solutions divide the global map into submaps, forming some kind of graph or tree to represent the structure of the environment, while the metric details are captured in the submaps. This work presents a novel algorithm that is able to compute a physically feasible relative pose between two overlapping grid maps. Our algorithm can be used for correspondence search (data association), but also for integrating negative information in a unified way. This paper proposes a discrepancy measure between two overlapping grid maps and its application in a quasi Newton optimization algorithm, with the hypothesis that minimizing such discrepancy could provide useful information for SLAM. Experimental evidence is provided showing the high potential of the algorithm

Fast processing of grid maps using graphical multiprocessors

Grid mapping is a very common technique used in mobile robotics to build a continuous 2D representation of the environment useful for navigation purposes. Although its computation is quite simple and fast, this algorithm uses the hypothesis of a known robot pose. In practice, this can require the re-computation of the map when the estimated robot poses change, as when a loop closure is detected. This paper presents a parallelization of a reference implementation of the grid mapping algorithm, which is suitable to be fully run on a graphics card showing huge processing speedups (up to 50×) while fully releasing the main processor, which can be very useful for many Simultaneous Localization and Mapping algorithms

Aerodynamic optimization of propellers for High Altitude Pseudo-Satellites

[EN] The propulsion system of High-Altitude Platform Stations or High-Altitude Pseudo-Satellites (HAPS) is commonly based on propellers. The properties of the atmosphere at those high altitudes and the characteristic speed of HAPS entail that the flight is performed at very low Reynolds numbers. Hence, the aerodynamic behavior of the propeller sections changes substantially from the hub to the tip of the blades. Under those circumstances, the ordinary methods to develop optimized propellers are not useful and must be modified. We present a method of propeller design adapted to HAPS features. It combines traditional solutions with modern numerical tools. Specifically, Theodorsen analytical theory is used to minimize induced drag. This process leaves one free parameter that it is fixed optimizing a cost function depending on the Reynolds number with a viscous-potential numerical code. It leads to an optimal determination of the geometrical characteristics of the propeller, i.e., chord and pitch distribution, increasing its total efficiency. The resulting algorithm has low computational requirements what makes it very appropriate for the preliminary design of HAPS missions, when it is necessary to simulate many different cases. That methodology has been applied to a relatively small HAPS airship with a wind speed of 10 m/s and required thrust of 100 N. The propeller is assumed to be made up of NACA4412 airfoils and the cost function to be minimized is given by the ratio of the 2D drag and lift coefficients. With those conditions we perform a parametric analysis where different combinations of diameters, thrust coefficients, and propeller advance ratios are considered. Over a Reynolds number range from 103 to 106, the new method provides a gain about 5% in the propeller efficiency when compared with the ordinary design procedure that employs a constant Reynolds number. That gain is of utmost importance for HAPS operations, since, for example, it allows an increase in the payload of up to 25% for a 90 meters long airship.S

On the capabilities and limitations of high altitude pseudo-satellites

[EN] The idea of self-sustaining air vehicles that excited engineers in the seventies has nowadays become a reality as proved by several initiatives worldwide. High altitude platforms, or Pseudo-satellites (HAPS), are unmanned vehicles that take advantage of weak stratospheric winds and solar energy to operate without interfering with current commercial aviation and with enough endurance to provide long-term services as satellites do. Target applications are communications, Earth observation, positioning and science among others. This paper reviews the major characteristics of stratospheric flight, where airplanes and airships will compete for best performance. The careful analysis of involved technologies and their trends allow budget models to shed light on the capabilities and limitations of each solution. Aerodynamics and aerostatics, structures and materials, propulsion, energy management, thermal control, flight management and ground infrastructures are the critical elements revisited to assess current status and expected short-term evolutions. Stratospheric airplanes require very light wing loading, which has been demonstrated to be feasible but currently limits their payload mass to few tenths of kilograms. On the other hand, airships need to be large and operationally complex but their potential to hover carrying hundreds of kilograms with reasonable power supply make them true pseudo-satellites with enormous commercial interest. This paper provides useful information on the relative importance of the technology evolutions, as well as on the selection of the proper platform for each application or set of payload requirements. The authors envisage prompt availability of both types of HAPS, aerodynamic and aerostatic, providing unprecedented services.SIEuropean Space Agenc

Colaboración del Grupo SEA con empresas para la propuesta y realización de PFC

XII Congreso de Tecnologías Aplicadas a la Enseñanza de la Electrónica (TAEE), 2016, Sevilla (España)El presente artículo describe la experiencia de 8 años del Grupo de Sistemas Electrónicos de Alimentación (SEA) de la Universidad de Oviedo en la propuesta, y realización de Proyectos Fin de Carrera (PFC) en colaboración con diversas empresas. Además, se detalla la metodología y la planificación aplicada, así como los resultados que se han obtenido de esta experiencia y sus principales conclusiones. De especial interés es la evolución que ha asumido y madurado el SEA a la hora de proponer y abordar el PFC en colaboración con empresas a lo largo de estos años. Esta evolución ha sido muy dependiente del formato del PFC a realizar por el alumno y las necesidades de la empresa, cristalizando en una metodología y planificación propia concreta para tres tipos de PFC. Finalmente, se presentarán los resultados obtenidos de esta experiencia y las conclusiones obtenidas para trabajos futuro

Auxiliary power supply based on a modular ISOP Flyback configuration with very high input voltage

This paper proposes a Flyback-based Input-Series Output-Parallel (ISOP) Auxiliary Power Supply (APS), intended to feed the control system of the cells of a Solid-State Transformer (SST). The SST topology is based on a modular Multiport Multilevel Converter (MMC). Energization of the cells auxiliary circuitry is not trivial due to the high voltages involved (tens of kV for the electric power distribution system), most of the commercially available control and driving circuitry not being usable due to the isolation requirements. It is possible to energize the control circuitry from an APS, connected to the cell capacitor voltage. However, in the SST under consideration, cells target DC voltage is in the range of 1.5kV to 2.5kV. Design of an APS capable of feeding the auxiliary circuitry from such high voltage and the required isolation is not trivial. A modular APS using autonomous Flyback converters in Continuous Conduction Mode (CCM) and based on commercial AC adapters is proposed in this paper. The solution is scalable and therefore applicable to cells with larger DC voltage

Trace Elements Analysis of Tunisian and European Extra Virgin Olive Oils by ICP-MS and Chemometrics for Geographical Discrimination

The aim of this study was to investigate the levels of trace elements in olive oils from different locations and their use for geographical authentication. Concentrations of seventeen elements were determined in a total of 42 olive oils from Tunisia, Spain (Basque country), and southern France, and in nine soil samples from Tunisia by quadrupole inductively plasma mass spectrometry. The compilation of appropriate techniques integrated into the analytical procedure achieved a precision (RSD) between 2% and 15% and low limits of detection (between 0.0002 and 0.313 µg kg−1). The accuracy of the analytical method applied for olive oil analysis was evaluated using SRM NIST 2387 Peanut butter. The recoveries obtained after microwave-assisted digestion for the certified elements ranged between 86% and 102%. Concentrations of non-certified elements (V, Cr, Co, Ni, Ba, Rb, Sr, Cd, Pb, and As) were presented. The use of Pearson correlation applied on paired Tunisian oil/soil samples has shown that several elements (Mg, Mn, Ni, and Sr) were significantly correlated. The multivariate statistics using principal component analysis have successfully discriminated against three studied origins. The most significant variables were the elemental concentrations of Cu, Cr, Fe, Mn, Sr, V, and Zn. This study shows the potential of applying trace elements profiles for olive oil geographical discrimination.This research was funded by European Project TunTwin from the Horizon 2020 Framework program of the European Union under grant No. 952306. It was also funded by the French ANR EquiPex MARSS project with a contribution of the METROFOOD ESFRI project. This work was partially supported by the Euskadi/Nouvelle Aquitaine/Navarra Eurorregion through the research project ISOTOPO (with agreement no. 2020/3). The financial support of a Ph.D. grant for Emna G. Nasr has been provided by the “Excellence Eiffel” scholarship of Campus France, the European project “TunTwin” and the scholarship “bourse d’alternance” of University Tunis El Manar, Ministry of Higher Education and Scientific Research in Tunisia