5,564 research outputs found

    An integrated dexterous robotic testbed for space applications

    Get PDF
    An integrated dexterous robotic system was developed as a testbed to evaluate various robotics technologies for advanced space applications. The system configuration consisted of a Utah/MIT Dexterous Hand, a PUMA 562 arm, a stereo vision system, and a multiprocessing computer control system. In addition to these major subsystems, a proximity sensing system was integrated with the Utah/MIT Hand to provide capability for non-contact sensing of a nearby object. A high-speed fiber-optic link was used to transmit digitized proximity sensor signals back to the multiprocessing control system. The hardware system was designed to satisfy the requirements for both teleoperated and autonomous operations. The software system was designed to exploit parallel processing capability, pursue functional modularity, incorporate artificial intelligence for robot control, allow high-level symbolic robot commands, maximize reusable code, minimize compilation requirements, and provide an interactive application development and debugging environment for the end users. An overview is presented of the system hardware and software configurations, and implementation is discussed of subsystem functions

    Estudo experimental do comportamento ocular em trabalhadores administrativos como um indicador de conforto visual em situação de risco de encadeamento

    Get PDF
    The daylight impact on the visual environment is fundamental on visual display terminal work (VDT). Visual performance and visual comfort should be considered for equal. The study (n=16) was performed at the experimental lighting laboratory. Office work with VDT was evaluated using STROOP task in two orientations: (with/without solar presence in the visual field). Our hypothesis states the existence of a relationship between ocular behavior and visual comfort of workers. An eye-tracker was employed in order to record the ocular gestural parameters: blinks, direction of gaze, eye aperture (Degree of eye?s openness) and pupil size, which were correlated with the vertical illuminance at the eye. Visual comfort was assessed with Glare Sensation Vote. Results indicate a strong negative linear correlation between eye illuminance and the degree of eye?s openness in the direct sunlight scenario (p=-0.636; s=0.008) and in diffuse light scenario (p=-0.661; s=0.005), that could be the main predictor of visual discomfort. This experiment allowed us to explore eye behavior patterns that could be visual comfort indices under glare risk situations.O impacto a luz do dia no ambiente visual é fundamental para o trabalho no Ecrã de Visualização de Dados (EDV). Desempenho visual e conforto visual devem ser considerados em igual. O estudo (n = 16) foi realizado no laboratório experimental de iluminação. O trabalho de escritório com EDV foi avaliado utilizando a tarefa de Stroop em duas orientações: (com / sem presença solar no campo visual). A nossa hipótese afirma a existência de uma relação entre o comportamento ocular e conforto visual dos trabalhadores. Um “eye-tracker” foi desenvolvido para gravar os parâmetros gestuais oculares: pestanejar, direção do olhar, abertura dos olhos (Grau de abertura do olho) e tamanho da pupila, que foram correlacionados com a iluminância vertical no olho. Conforto visual foi avaliado com a escala de sensação de encadeamento. Os resultados indicam uma correlação linear negativa forte entre a luminosidade dos olhos e do grau de abertura de olho no cenário de luz solar direta (p = -0,636; s = 0,008) e no cenário de luz difusa (p = -0,661; s = 0,005), que poderia ser o principal preditor de desconforto visual. Esta experiência permitiu-nos explorar padrões de comportamento do olho que poderiam ser os índices de conforto visual em situação de risco de encadeamento.Fil: Yamin Garretón, Julieta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Rodriguez, Roberto Germán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Pattini, Andrea Elvira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

    Pervasive and standalone computing: The perceptual effects of variable multimedia quality.

    Get PDF
    The introduction of multimedia on pervasive and mobile communication devices raises a number of perceptual quality issues, however, limited work has been done examining the 3-way interaction between use of equipment, quality of perception and quality of service. Our work measures levels of informational transfer (objective) and user satisfaction (subjective)when users are presented with multimedia video clips at three different frame rates, using four different display devices, simulating variation in participant mobility. Our results will show that variation in frame-rate does not impact a user’s level of information assimilation, however, does impact a users’ perception of multimedia video ‘quality’. Additionally, increased visual immersion can be used to increase transfer of video information, but can negatively affect the users’ perception of ‘quality’. Finally, we illustrate the significant affect of clip-content on the transfer of video, audio and textual information, placing into doubt the use of purely objective quality definitions when considering multimedia presentations

    Feasibility study of an Integrated Program for Aerospace-vehicle Design (IPAD) system. Volume 2: Characterization of the IPAD system, phase 1, task 1

    Get PDF
    The aircraft design process is discussed along with the degree of participation of the various engineering disciplines considered in this feasibility study

    Army-NASA aircrew/aircraft integration program. Phase 5: A3I Man-Machine Integration Design and Analysis System (MIDAS) software concept document

    Get PDF
    This is the Software Concept Document for the Man-machine Integration Design and Analysis System (MIDAS) being developed as part of Phase V of the Army-NASA Aircrew/Aircraft Integration (A3I) Progam. The approach taken in this program since its inception in 1984 is that of incremental development with clearly defined phases. Phase 1 began in 1984 and subsequent phases have progressed at approximately 10-16 month intervals. Each phase of development consists of planning, setting requirements, preliminary design, detailed design, implementation, testing, demonstration and documentation. Phase 5 began with an off-site planning meeting in November, 1990. It is expected that Phase 5 development will be complete and ready for demonstration to invited visitors from industry, government and academia in May, 1992. This document, produced during the preliminary design period of Phase 5, is intended to record the top level design concept for MIDAS as it is currently conceived. This document has two main objectives: (1) to inform interested readers of the goals of the MIDAS Phase 5 development period, and (2) to serve as the initial version of the MIDAS design document which will be continuously updated as the design evolves. Since this document is written fairly early in the design period, many design issues still remain unresolved. Some of the unresolved issues are mentioned later in this document in the sections on specific components. Readers are cautioned that this is not a final design document and that, as the design of MIDAS matures, some of the design ideas recorded in this document will change. The final design will be documented in a detailed design document published after the demonstrations

    Estudio de características frecuenciales de los potenciales de error para el control en continuo mediante interfaces cerebro-máquina

    Get PDF
    El registro, análisis y procesado de las señales eléctricas generadas por el cerebro tiene aplicaciones en diversos ámbitos como la medicina, la rehabilitación o el entretenimiento. En los últimos años el campo de las interfaces cerebro-computador(BCI) ha experimentado grandes avances incluyendo el control multi-dimensional de dispositivos. En este contexto, desde la Universidad de Zaragoza se ha trabajado en la utilización de información relacionada con los errores para proporcionar información de retro-alimentación durante el uso de la BCI. En particular, se han utilizado los potenciales de error, un tipo de potencial evocado (ERP) que aparece cuando ocurre un evento no esperado. Las interfaces cerebro-computador, incluyendo aquellas basados en potenciales de error, utilizan información en el dominio del tiempo y requieren una fase de calibración previa al control de un dispositivo. Esto implica una gran dificultad para el desarrollo de esta tecnología ya que la señal cerebral depende tanto del usuario, como del día o de la tarea a realizar. Aunque se ha demostrado que los potenciales de error son estables a lo largo del tiempo, trabajos recientes señalan que existen diferencias en la respuesta cerebral en función de la tarea a realizar, en función de la dificultad al evaluar la tarea. Otra dificultad asociada a este tipo de señales es la necesidad de tener un evento muy marcado en el tiempo, o trigger, para elicitar el potencial. Esto dificulta el uso de estos potenciales en situaciones de control realistas como por ejemplo un robot móvil. En este caso, no está claro cuándo el usuario va a percibir un error y si se va a generar el potencial de error correspondiente. Los objetivos de esta tesis de Máster son analizar la posibilidad de eliminar el trigger de este tipo de señales 1) estudiando un nuevo tipo de características en el dominio de la frecuencia y analizando si estas últimas son más robustas ante variaciones en la latencia de respuesta del potencial de error; y 2) evaluando la capacidad de estas características para proporcionar información de retro-alimentación durante el control en continuo de un dispositivo. Para ello, este trabajo se divide en tres partes: 1) Estudio y comparación de la generalización de las características temporales y frecuenciales de los potenciales de error cuando se hace transferencia entre tareas en protocolos con un marcador bien definido, es decir, acciones discretas. Refiriéndose con transferencia a entrenar un clasificador con las características extraídas de una tarea y emplearlo para reconocer eventos en una tarea distinta. 2) Diseño de un protocolo (en pantalla) para el estudio de los potenciales en continuo (acciones continuas donde no existe marcador del evento, o si lo existe no se conoce dónde está). Adquisición de datos de EEG con varios sujetos. Procesamiento de datos para analizar la presencia de potenciales de error y su detección en continuo. 3) Diseño de un protocolo experimental para el control en línea de un robot móvil mediante el uso de potenciales de error y su clasificación en continuo. Experimentación preliminar con varios sujetos y análisis de los resultados obtenidos

    Engineering data compendium. Human perception and performance. User's guide

    Get PDF
    The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

    The memory glasses : wearable computing for just-in-time memory support

    Get PDF
    Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2004.Includes bibliographical references (p. 173-181).This thesis documents a body of wearable computing research surrounding the development of the Memory Glasses, a new type of proactive memory support technology. The Memory Glasses combines features of existing memory support technologies (such as PDAs) with a context aware delivery system and a low-attention cuing interface. The goal of the Memory Glasses is to provide effective just-in-time memory support while mitigating some of the distraction and over-reliance problems that can result from the use of more conventional memory support technology. The Memory Glasses research is a synthesis of the author's six years of work on wearable computing. This thesis documents the author's intellectual contributions in the areas of wearable computing hardware architectures, software architectures, and human-computer interaction. Specific topics include the MIThril wearable computing research platform, the Enchantment middlewear, the MIThril Real-Time Context Engine, the author's modified Seven Stages of Action model and five principles of low-attention wearable human computer interaction, as well as the author's research in the use of subliminal cuing for just-in-time memory support. Although memory support is the unifying theme of this dissertation, the author's research has seen application in a number of other areas, including the mapping of social networks, research in human physiology and biomedical applications, and group situation awareness and command, control, and communications. A selection of these applications is briefly presented as support for the importance of the author's intellectual contributions.by Richard W. DeVaul.Ph.D
    corecore