Percepción basada en visión estereoscópica, planificación de trayectorias y estrategias de navegación para exploración robótica autónoma

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de Ingeniería del Software e Inteligencia artificial, leída el 13-05-2015En esta tesis se trata el desarrollo de una estrategia de navegación autónoma basada en visión artificial para exploración robótica autónoma de superficies planetarias. Se han desarrollado una serie de subsistemas, módulos y software específicos para la investigación desarrollada en este trabajo, ya que la mayoría de las herramientas existentes para este dominio son propiedad de agencias espaciales nacionales, no accesibles a la comunidad científica. Se ha diseñado una arquitectura software modular multi-capa con varios niveles jerárquicos para albergar el conjunto de algoritmos que implementan la estrategia de navegación autónoma y garantizar la portabilidad del software, su reutilización e independencia del hardware. Se incluye también el diseño de un entorno de trabajo destinado a dar soporte al desarrollo de las estrategias de navegación. Éste se basa parcialmente en herramientas de código abierto al alcance de cualquier investigador o institución, con las necesarias adaptaciones y extensiones, e incluye capacidades de simulación 3D, modelos de vehículos robóticos, sensores, y entornos operacionales, emulando superficies planetarias como Marte, para el análisis y validación a nivel funcional de las estrategias de navegación desarrolladas. Este entorno también ofrece capacidades de depuración y monitorización.La presente tesis se compone de dos partes principales. En la primera se aborda el diseño y desarrollo de las capacidades de autonomía de alto nivel de un rover, centrándose en la navegación autónoma, con el soporte de las capacidades de simulación y monitorización del entorno de trabajo previo. Se han llevado a cabo un conjunto de experimentos de campo, con un robot y hardware real, detallándose resultados, tiempo de procesamiento de algoritmos, así como el comportamiento y rendimiento del sistema en general. Como resultado, se ha identificado al sistema de percepción como un componente crucial dentro de la estrategia de navegación y, por tanto, el foco principal de potenciales optimizaciones y mejoras del sistema. Como consecuencia, en la segunda parte de este trabajo, se afronta el problema de la correspondencia en imágenes estéreo y reconstrucción 3D de entornos naturales no estructurados. Se han analizado una serie de algoritmos de correspondencia, procesos de imagen y filtros. Generalmente se asume que las intensidades de puntos correspondientes en imágenes del mismo par estéreo es la misma. Sin embargo, se ha comprobado que esta suposición es a menudo falsa, a pesar de que ambas se adquieren con un sistema de visión compuesto de dos cámaras idénticas. En consecuencia, se propone un sistema experto para la corrección automática de intensidades en pares de imágenes estéreo y reconstrucción 3D del entorno basado en procesos de imagen no aplicados hasta ahora en el campo de la visión estéreo. Éstos son el filtrado homomórfico y la correspondencia de histogramas, que han sido diseñados para corregir intensidades coordinadamente, ajustando una imagen en función de la otra. Los resultados se han podido optimizar adicionalmente gracias al diseño de un proceso de agrupación basado en el principio de continuidad espacial para eliminar falsos positivos y correspondencias erróneas. Se han estudiado los efectos de la aplicación de dichos filtros, en etapas previas y posteriores al proceso de correspondencia, con eficiencia verificada favorablemente. Su aplicación ha permitido la obtención de un mayor número de correspondencias válidas en comparación con los resultados obtenidos sin la aplicación de los mismos, consiguiendo mejoras significativas en los mapas de disparidad y, por lo tanto, en los procesos globales de percepción y reconstrucción 3D.Depto. de Ingeniería de Software e Inteligencia Artificial (ISIA)Fac. de InformáticaTRUEunpu

Crustal structure and active processes along the northern Hipaniola margin: application to the characterization of tsunamigenic sources associated tsunamigenic hazard

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Geológicas, Departamento de Geodinámica, Estratigrafía y Paleontología, leída el 22/01/2021The North American (NOAM) plate converges with the Caribbean (CARIB) plate at a rate of 20.0 ± 0.4 mm/yr. towards 254 ± 1°. Plate convergence is highly oblique (20–10°), resulting in a complex crustal boundary with along-strike segmentation, strain partitioning and microplate tectonics. The northern margin of Hispaniola records the oblique collision/underthrusting of the Bahamas Carbonate Province with the island-arc. Due to the collision, northern Hispaniola has suffered several natural disasters caused by major earthquakes and tsunamis, such as the historic earthquake of 1842, thet sunami caused by earthquake-driven slumping in 1918 in the Mona Passage, the seismic crisis of 1943–1953 with five events of M > 7.0 or the seismic crisis of 2003 with amain shock of M6.3 and a large aftershock of M5.3...La placa Norteamericana (NOAM) converge con la placa del Caribe (CARIB) a una velocidad de 20,0 ± 0,4 mm/año con una dirección de 254 ± 1°. La convergencia de la placa es muy oblicua (20-10°), resultando en un complejo límite de placas en el que hay segmentación tectónica, deformación compartimentada y tectónica de microplacas. El margen norte de La Española registra la colisión oblicua de la Provincia Carbonática de las Bahamas con el arco de la isla. Debido a esta colisión, el márgen norte de La Española ha sufrido varios desastres naturales causados por grandes terremotos y tsunamis, como el terremoto histórico terremoto de 1842, el tsunami causado por el deslizamiento submarino provocado por un terremoto en 1918 en el Pasaje de Mona, lacrisis sísmica de 1943-1953 con cinco eventos de M > 7,0 o la crisis sísmica de 2003con un terremoto principal de M6,3 y una gran réplica de M5,3...Fac. de Ciencias GeológicasTRUEunpu

MEDIATION: An eMbEddeD System for Auditory Feedback of Hand-water InterAcTION while Swimming

Cesarini D, Calvaresi D, Farnesi C, et al. MEDIATION: An eMbEddeD System for Auditory Feedback of Hand-water InterAcTION while Swimming. Procedia Engineering. 2016;147:324-329.In swimming sport, the proper perception of moving water masses is a key factor. This paper presents an embedded system for the acquisition of values of pressure on swimmers hands and their transformation into sound. The sound, obtained using sonification, is used as an auditive representation of hand-water interactions while swimming in water. The sound obtained is used as an auditive feedback for the swimmer and as an augmented communication channel between the swimming trainer and the athlete. The developed system is self-contained, battery powered and able to work continuously for over eight hours, thus, representing a viable solution for daily usage in swimmers training. Preliminary results from in-pool experiments with both novel and experienced swimmers demonstrate the high acceptability of this technology and its promising future evolution and usage possibilities

Amoeboid Shape Dynamics on Flat and Topographically Modified Surfaces

I present an analysis of the shape dynamics of the amoeba Dictyostelium discoideum, a model system for the study of cellular migration. To better understand cellular migration in complicated 3-D environments, cell migration was studied on simple 3-D surfaces, such as cliffs and ridges. D. discoideum interact with surfaces without forming mature focal adhesion complexes. The cellular response to the surface topography was characterized by measuring and looking for patterns in cell shape. Dynamic cell shape is a measure of the interaction between the internal biochemical state of a cell and its external environment. For D. discoideum migrating on flat surfaces, waves of high boundary curvature were observed to travel from the cell front to the cell back. Curvature waves are also easily seen in cells that do not adhere to a surface, such as cells that are electrostatically repelled from the coverslip or cells that are extended over the edge of micro-fabricated cliffs. At the leading edge of adhered cells, these curvature waves are associated with protrusive activity, suggesting that protrusive motion can be thought of as a wave-like process. The wave-like character of protrusions provides a plausible mechanism for the ability of cells to swim in viscous fluids and to navigate complex 3-D topography. Patterning of focal adhesion complexes has previously been implicated in contact guidance (polarization or migration parallel to linear topographical structures). However, significant contact guidance is observed in D. discoideum, which lack focal adhesion complexes. Analyzing the migration of cells on nanogratings of ridges spaced various distances apart, ridges spaced about 1.5 micrometers apart were found to guide cells best. Contact guidance was modeled as an interaction between wave-like processes internal to the cell and the periodicity of the nanograting. The observed wavelength and speed of the oscillations that best couple to the surface are consistent with those of protrusive dynamics. Dynamic sensing via actin or protrusive dynamics might then play a role in contact guidance

Tectonic and sedimentary processes of the southeast Alaska margin

Strike-slip tectonics dominate the southeast Alaska margin. The Queen Charlotte-Fairweather Fault transform system extends ~1200 km from southern Canada north to Yakutat Bay, Alaska, accommodating nearly 4.5 cm/yr of dextral offset between the Pacific and North American plates. This dissertation aims to better characterize the transform plate boundary by examining the accommodation of oblique transpression, crustal structure, seismogenic faults, and tectonic influence on regional sedimentary processes. We address fundamental tectonic questions utilizing a suite of geophysical data including multichannel seismic (MCS) reflection, bathymetry, magnetics, gravity, and earthquake data. A 2011 MCS survey reveals subsurface channel deposits related to the development of the deep-sea Baranof sedimentary fan in the Gulf of Alaska. We find that Baranof Fan channels have avulsed consistently southward, affected by the changing position of channel heads relative to sediment sources along the shelf edge due to strike-slip motion along the Queen Charlotte Fault (QCF). Baranof Fan sediments sit atop a flexural depression in the Pacific crust near the QCF, which developed between ~6 Ma and ~2 Ma. We interpret the flexure to be an artifact of oblique convergence along the southern QCF, preserved by sedimentary loading in part from the Baranof Fan. ~150 km of the QCF near the Pacific flexural depression ruptured in January 2013, producing a M [subscript]w 7.5 earthquake near Craig, Alaska. A tomographic inversion of Craig aftershock data reveals a low velocity zone on the Pacific side of the plate boundary at seismogenic depths, which may indicate the contrast of a warm, young Pacific crust along the older, colder North American crust. These results have relevance for rupture directionality and future seismic hazard along the QCF. Finally, we revisit seismic hazard associated with the 10 September 1899 Mw 8.2 earthquake at the northern termination of the transform system near Yakutat Bay, Alaska. We quantify uncertainty on coseismic uplift measurements and integrate various geophysical data, including a 2012 MCS survey, to provide an updated fault map and tectonic model of the Yakutat Bay region. Our results support a subduction-related rupture of the 10 September event with limited slip along the transpressive termination of the Fairweather Fault.Geological Science

How touch and hearing influence visual processing in sensory substitution, synaesthesia and cross-modal correspondences

Sensory substitution devices (SSDs) systematically turn visual dimensions into patterns of tactile or auditory stimulation. After training, a user of these devices learns to translate these audio or tactile sensations back into a mental visual picture. Most previous SSDs translate greyscale images using intuitive cross-sensory mappings to help users learn the devices. However more recent SSDs have started to incorporate additional colour dimensions such as saturation and hue. Chapter two examines how previous SSDs have translated the complexities of colour into hearing or touch. The chapter explores if colour is useful for SSD users, how SSD and veridical colour perception differ and how optimal cross-sensory mappings might be considered. After long-term training, some blind users of SSDs report visual sensations from tactile or auditory stimulation. A related phenomena is that of synaesthesia, a condition where stimulation of one modality (i.e. touch) produces an automatic, consistent and vivid sensation in another modality (i.e. vision). Tactile-visual synaesthesia is an extremely rare variant that can shed light on how the tactile-visual system is altered when touch can elicit visual sensations. Chapter three reports a series of investigations on the tactile discrimination abilities and phenomenology of tactile-vision synaesthetes, alongside questionnaire data from synaesthetes unavailable for testing. Chapter four introduces a new SSD to test if the presentation of colour information in sensory substitution affects object and colour discrimination. Chapter five presents experiments on intuitive auditory-colour mappings across a wide variety of sounds. These findings are used to predict the reported colour hallucinations resulting from LSD use while listening to these sounds. Chapter six uses a new sensory substitution device designed to test the utility of these intuitive sound-colour links for visual processing. These findings are discussed with reference to how cross-sensory links, LSD and synaesthesia can inform optimal SSD design for visual processing

SSERVI Annual Report: Year 4

The SSERVI Central Office forms the organizational, administrative and collaborative hub for the domestic and international teams, and is responsible for advocacy and ensuring the long-term health and relevance of the Institute. SSERVI has increased the cross-talk between NASAs space and human exploration programs, which is one of our primary goals. We bring multidisciplinary teams together to address fundamental and strategic questions pertinent to future human space exploration, and the results from that research are the primary products of the institute. The team and international partnership reports contain summaries of 2017 research accomplishments. Here we present the 2017 accomplishments by the SSERVI Central Office that focus on: 1) Supporting Our Teams, 2) Community Building, 3) Managing the Solar System Treks Portal (SSTP), and 4) Public Engagement

Multi-Sensory Interaction for Blind and Visually Impaired People

This book conveyed the visual elements of artwork to the visually impaired through various sensory elements to open a new perspective for appreciating visual artwork. In addition, the technique of expressing a color code by integrating patterns, temperatures, scents, music, and vibrations was explored, and future research topics were presented. A holistic experience using multi-sensory interaction acquired by people with visual impairment was provided to convey the meaning and contents of the work through rich multi-sensory appreciation. A method that allows people with visual impairments to engage in artwork using a variety of senses, including touch, temperature, tactile pattern, and sound, helps them to appreciate artwork at a deeper level than can be achieved with hearing or touch alone. The development of such art appreciation aids for the visually impaired will ultimately improve their cultural enjoyment and strengthen their access to culture and the arts. The development of this new concept aids ultimately expands opportunities for the non-visually impaired as well as the visually impaired to enjoy works of art and breaks down the boundaries between the disabled and the non-disabled in the field of culture and arts through continuous efforts to enhance accessibility. In addition, the developed multi-sensory expression and delivery tool can be used as an educational tool to increase product and artwork accessibility and usability through multi-modal interaction. Training the multi-sensory experiences introduced in this book may lead to more vivid visual imageries or seeing with the mind’s eye