250 research outputs found
USBL Integration and Assessment in a Multisensor Navigation Approach for AUVs 1 1This work is partially supported by Ministry of Economy and Competitiveness under contracts TIN2014-58662-R, DPI2014-57746-C3-2-R and FEDER funds.
No full textThis paper presents the design and assessment of an USBL-aided navigation approach for Autonomous Underwater Vehicles (AUV). The system integrates an Ultra-Short Base Line (USBL) acoustic modem and positioning device in a two-parallel Extended Kalman Filter (EKF) navigation schema, which also includes the measurements provided by an Inertial Measurement Unit (IMU), a Doppler Velocity Log (DVL), a Visual Odometer (VO), a pressure sensor, and a Global Positioning System (GPS). In order to be integrated in the estimation filter, the precision of the USBL measurements is derived experimentally. Moreover, the accuracy of the system is evaluated using a ground truth (GT) trajectory produced by a visual Simultaneous Localization and Mapping (SLAM) approach. Experimental results are obtained from marine datasets gathered in the north coast of Mallorca with an AUV, model SPARUS II.</p
An USBL-aided multisensor navigation system for field AUVs
No full textThis paper presents the integration of an Ultra Short Base Line (USBL) acoustic modem and positioning device in a two-parallel Extended Kalman Filter (EKF) multisensor navigation schema for an Autonomous Underwater Vehicle (AUV). The system consists of a first odometric EKF position estimator fed with the measurements provided by an Inertial Measurement Unit (IMU), a Doppler Velocity Log (DVL), a visual tracker and a pressure sensor, and a second corrective EKF that fuses the previous sensors with the Global Positioning System (GPS) and the corrected delayed-state Ultra Short Base Line (USBL) position data. The first filter is aimed to compute a highly reliable vehicle position estimation from the sensor suit that produces high frequency relative navigation data. This estimation is essential to correct the delay of the USBL position measurements. The objective of the second filter is to give the vehicle a global pose, eliminating the drift inherent to deadreckoning sensors by integrating absolute positions (GPS and USBL) provided at low frequencies. The effects of the USBL integration in the global localization module are evaluated in a simulated environment, and compared to a ground truth trajectory with the pose estimates given by the first EKF, the USBL raw data and the output of the second EKF, showing an effective reduction of the trajectory error
Towards a new methodology to evaluate the environmental impact of a marine outfall using a lightweight AUV
No full textEvaluating the impact of sewage discharges on the marine environment with a lightweight AUV
No full textEnvironmental studies that use small Autonomous Underwater Vehicles (AUVs) can survey wider and deeper areas, compared to traditional methods, at a reasonable cost. Thanks to the precise vehicle navigation systems, the data collected can be accurately geolocalized. Besides, lightweight vehicles can be deployed from the shore or from small boats and programmed by means of user-friendly graphical interfaces, thus reducing and simplifying the need of human resources and infrastructures. Based on such a technology, this paper presents a framework to assess the environmental impact of a marine sewage outfall set in the Bay of Palma (Mallorca, Spain). We report the results of the analysis of the images recorded in the course of six missions conducted with an AUV. The plan was designed after a microbiological analysis detected the presence of cyanobacteria in a sample of sand and water collected by scuba divers close to the sewer pipe mouth
Visual sensing for autonomous underwater exploration and intervention tasks
No full textUnderwater activities, such as surveying or interventions, carried out by autonomous robots, can benefit greatly from using a vision system. Optics based systems provide information at a spatial and temporal resolution higher than their acoustic counterparts. At present, they are the best option when high precision maneuvering and manipulation is needed, if there is good visibility. This paper presents a new system designed to provide visual information in submarine tasks such as navigation, surveying, mapping and intervention. The main advantages of our system, called Fugu-f (Fugu flexible), are its robustness in both the mechanical structure and the software components, its flexibility, since it is installed as an external module and is adaptable to different vehicles and missions, and its capacity to operate in real-time. Experiments of surveying and object manipulation carried out in real conditions in the context of the TRIDENT project show the suitability of the system and its scientific and industrial potential applications.</p
Inertial Sensor Self-Calibration in a Visually-Aided Navigation Approach for a Micro-AUV
No full textThis paper presents a new solution for underwater observation, image recording, mapping and 3D reconstruction in shallow waters. The platform, designed as a research and testing tool, is based on a small underwater robot equipped with a MEMS-based IMU, two stereo cameras and a pressure sensor. The data given by the sensors are fused, adjusted and corrected in a multiplicative error state Kalman filter (MESKF), which returns a single vector with the pose and twist of the vehicle and the biases of the inertial sensors (the accelerometer and the gyroscope). The inclusion of these biases in the state vector permits their self-calibration and stabilization, improving the estimates of the robot orientation. Experiments in controlled underwater scenarios and in the sea have demonstrated a satisfactory performance and the capacity of the vehicle to operate in real environments and in real time
Proyecto de las estructuras para la conexión peatonal de los andenes de la estación de Font de Sant Lluis en Valencia
No full text[EN] This present TFG consist in the execution of a construction of underground passage, under the platforms of the La Font Sant Lluis Valencia station, as well as the necessary structures for access to it from the platforms, with the purpose to improve workers safety ADIF, that currently are crossing the track in surface.
Therefore, I did a study of solutions of different structural alternatives, establishing six possible solutions, studying in each solutions, their costs, both economic and temporary, because the execution of this construction temporarily incapacitates traffic of the station.
As a result, after studying different structural alternatives, I choose the fourth alternative, which it consists of the execution of the underpass using prefabricated reinforced concrete modules, and the execution of a micropile screen for the mouths of access. This solution have a base budget of 98,815.83 € and a duration of 31 days.[ES] El presente TFG consiste en la ejecución de una obra de paso subterránea, bajo los andenes de la estación La Font Sant Lluis de Valencia, así como las estructuras necesarias para el acceso al mismo desde los andenes, con el fin de que sirva para mejorar la seguridad de los trabajadores de ADIF, que actualmente cruzan estas vías en superficie.
Para ello se realiza un estudio de soluciones, de las diferentes alternativas estructurales, estableciendo seis posibles soluciones, estudiando en cada una de ellas, sus costes, tanto económico como temporal, ya que la ejecución de esta obra de paso, inhabilita temporalmente el tráfico en la estación.
Por tanto tras estudiar las distintas alternativas estructurales, escogemos la alternativa cuatro, la cual está compuesta por la ejecución del paso inferior mediante módulos prefabricados de hormigón armado, y la ejecución de una pantalla de micropilotes para las embocaduras de acceso al mismo. Teniendo el presupuesto base de licitación un coste de 98.815,83 € y una duración de 31 días.[CA] El present TFG consisteix en l'execució d'una obra de pas subterrània, davall les andanes de l'estació La Font Sant Lluís de València, així com les estructures necessàries per a l'accés al mateix des de les andanes, a fi que servisca per a millorar la seguretat dels treballadors d'ADIF, que actualment creuen aquestes vies en superfície.
Per a això es realitza un estudi de solucions, de les diferents alternatives estructurals, establint sis possibles solucions, estudiant en cada una d'elles, els seus costos, tant econòmic com temporal, ja que l'execució d'esta obra de pas, inhabilita temporalment el tràfic en l'estació.
Per tant després d'estudiar les distintes alternatives estructurals, triem l'alternativa quatre, la qual està composta per l'execució del pas inferior mediant mòduls prefabricats de formigó armat, i l'execució d'una pantalla de micropuntals per a les embocadures d'accés al mateix. Tenint el pressupost base de licitació un cost de 98.815,83€ i una duració de 31 dies."Martínez Santos, JL. (2015). Proyecto de las estructuras para la conexión peatonal de los andenes de la estación de Font de Sant Lluis en Valencia. https://riunet.upv.es/handle/10251/55334.Archivo delegad
UX-comments: Evaluation of User eXperience in E-learning [Dataset]
No full textIf you use this dataset, please cite the following paper: Sanchis-Font, Rosario; Castro-Bleda, Maria Jose; Gonzalez, Jose-Angel; Plal, Ferran; Hurtado, Lluis-F (2021). Cross-Domain Polarity Models to Evaluate User eXperience in E-learning. Neural Processing Letters, 53(5), 3199-3215. DOI: 10.1007/s11063-020-10260-5Virtual learning environments are growing in importance as fast as e-learning, which is becoming highly demanded by universities and students worldwide. We have investigated how to automatically evaluate User eXperience in this domain using sentiment analysis techniques. For this purpose, the UX-comments corpus has been built with the opinions of 583 users (107 English speakers and 476 Spanish speakers) about three learning management systems in different courses. All the collected opinions were manually labeled with polarity information (P=positive, N=negative, or NEU=neutral) by three human annotators, both at the whole opinion and sentence levels.
Dataset Information P NEU N Total
Spanish Observations 338 53 85 476
Spanish Sentences 404 41 142 587
English Observations 56 21 30 107
English Sentences 90 14 80 184Special thanks to the following biomedical organizations: Fundación IVI and Medigene Press S.L.; both have provided data from their Master and Posgraduate Courses through the academic stay research of Rosario Sanchis-Font, during 2017 and 2018. Many thanks to Carlos Turró-Ribalta and Ignacio Despujol-Zabala for supporting this research with data from UPV MOOCs.Sanchis Font, R.; Castro Bleda, MJ.; González Barba, JÁ.; Pla Santamaría, F.; Hurtado Oliver, LF. (2021). UX-comments: Evaluation of User eXperience in E-learning [Dataset]. Universitat Politècnica de València. https://doi.org/10.4995/Dataset/10251/21333
Double projectile humain en plein vol : Démonstration de Marina et Lluis Raluy
No full textLluis Raluy Iglesias (1911-1984), né à Carcassonne mais d’origine catalane, entre dans le monde de la performance spectaculaire par passion l’année de ses 18 ans. Ses exploits à la barre fixe effectués sur les plages de Sant Adria de Besos, attirent l’attention des barristes des Keistone Oliveras qui l’emmènent en tournée. Irrésistiblement attiré par les attractions sensationnelles, il fabrique un canon, s’entraîne avec sa sœur Juanita et s’embarque avec le Circo da Brasil dans une tournée en Amérique du Sud et en Afrique. Marié avec Marina Tomàs Jorba (1920-2013) qui devient également sa partenaire entre deux maternités, il se produit avec le canon au cirque britannique des Chipperfields en 1953, et dans les années 1960 au Cirque italien Moira Orfei, au cirque Toni Boltini aux Pays-Bas et au cirque Amar – direction Roche – en France, en 1968. L’exhibition est généralement proposée à l’extérieur du chapiteau : l’effet, plus spectaculaire sur une longue trajectoire, est idéal pour convaincre un public encore incertain d’acheter ses billets. Les deux projectiles humains se propulsent en même temps, non de deux canons, mais d’un seul fût à double gueule. Luis, Marina et leurs quatre enfants créent en 1970 leur propre cirque qui change de nom plusieurs fois pour devenir le Circ Museu Raluy, géré actuellement par Luis junior (1942-) et Carlos (1944-), eux-mêmes anciens homme-obus. Du bord de la piste du Circ Raluy, ou dans ses coulisses l’artiste Pujolboira (Ramon Pujol Boira, né en 1949) réalise de nombreux dessins et œuvres picturales qui, contextualisés avec chronologie et photographies, font en 1998 l’objet d’une publication éditée par le Circ Raluy de Luis et Carlos Raluy. Voir aussi : - Pujolboira, Circus, Circ Raluy , Girona, 1998. - 100 Anys de Circ. La familia Raluy, els origens 1911-2011, Homenaje a Lluis Raluy Iglesias , Madrid, Javier Sáinz Ediciones, 2011. - Luis Tomàs Raluy, El Circo de los Saltimbanquis , Madrid, Javier Sáinz Ediciones, 2013
El Sant Crist de l'Ermita de Llubí: una talla de Lluis Font i Martorell (1839-1904)
No full textAprofitant el centenari de la construcció dc l'Ermita del Sant Crist de Llubí s'ha
investigat l'autoria de la talla que dóna nom a l'Ermita a partir de quatre fonts
documentals arribant a la conclusió que és obra dc Lluís Font i Martorell (1839-
1904), escultor de temàtica religiosa i de clara inspiració renaixentista
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