44 research outputs found

    Humanoid Robots

    Get PDF
    For many years, the human being has been trying, in all ways, to recreate the complex mechanisms that form the human body. Such task is extremely complicated and the results are not totally satisfactory. However, with increasing technological advances based on theoretical and experimental researches, man gets, in a way, to copy or to imitate some systems of the human body. These researches not only intended to create humanoid robots, great part of them constituting autonomous systems, but also, in some way, to offer a higher knowledge of the systems that form the human body, objectifying possible applications in the technology of rehabilitation of human beings, gathering in a whole studies related not only to Robotics, but also to Biomechanics, Biomimmetics, Cybernetics, among other areas. This book presents a series of researches inspired by this ideal, carried through by various researchers worldwide, looking for to analyze and to discuss diverse subjects related to humanoid robots. The presented contributions explore aspects about robotic hands, learning, language, vision and locomotion

    From locomotion to cognition: Bridging the gap between reactive and cognitive behavior in a quadruped robot

    Full text link
    The cognitivistic paradigm, which states that cognition is a result of computation with symbols that represent the world, has been challenged by many. The opponents have primarily criticized the detachment from direct interaction with the world and pointed to some fundamental problems (for instance the symbol grounding problem). Instead, they emphasized the constitutive role of embodied interaction with the environment. This has motivated the advancement of synthetic methodologies: the phenomenon of interest (cognition) can be studied by building and investigating whole brain-body-environment systems. Our work is centered around a compliant quadruped robot equipped with a multimodal sensory set. In a series of case studies, we investigate the structure of the sensorimotor space that the application of different actions in different environments by the robot brings about. Then, we study how the agent can autonomously abstract the regularities that are induced by the different conditions and use them to improve its behavior. The agent is engaged in path integration, terrain discrimination and gait adaptation, and moving target following tasks. The nature of the tasks forces the robot to leave the ``here-and-now'' time scale of simple reactive stimulus-response behaviors and to learn from its experience, thus creating a ``minimally cognitive'' setting. Solutions to these problems are developed by the agent in a bottom-up fashion. The complete scenarios are then used to illuminate the concepts that are believed to lie at the basis of cognition: sensorimotor contingencies, body schema, and forward internal models. Finally, we discuss how the presented solutions are relevant for applications in robotics, in particular in the area of autonomous model acquisition and adaptation, and, in mobile robots, in dead reckoning and traversability detection

    Ontogeny and Adaptation: A Cross-Sectional Study of Primate Limb Elements

    Get PDF
    How primates achieve their adult skeletal form can be ascribed to two broad biological mechanisms: genetic inheritance, where morphological characters are regulated by an individual's phenotype over development; and plastic adaptation, where morphology responds to extrinsic factors engendered by the physical environment. While skeletal morphology should reflect an individual’s ecological demands throughout its life, only a limited amount of published research has considered how ontogeny and locomotor behaviour influence limb element form together. This thesis presents an investigation of long bone cross-sectional shape, size and strength, to inform how five catarrhine taxa adapt their limbs over development, and further, evaluate which limb regions more readily emit signals of plasticity or constraint along them. The sample includes Pan, Gorilla, Pongo, Hylobatidae and Macaca, subdivided into three developmental stages: infancy, juvenility and adulthood. Three-dimensional models of four upper (humerus and ulna) and lower (femur and tibia) limb elements were generated using a laser scanner and sectioned at proximal, midshaft and distal locations along each diaphysis. Three methods were used to compare geometry across the sample: 1) principal and anatomical axis ratios served as indices of section circularity, 2) polar section moduli evaluated relative strength between limb sections and 3) a geometric morphometric approach was developed to define section form. The results demonstrated that irrespective of taxonomic affinity, forelimb elements serve as strong indicators of posture and locomotor ontogenetic transitions, while hindlimb form is more reflective of body size and developmental shifts in body mass. Moreover, geometric variation at specific regions like the midhumerus was indistinguishable across all infant taxa in the sample, only exhibiting posture-specific signals among mature groups, while sections like the distal ulna exhibited little or no intraspecific variation over development. Identifying patterns of plasticity and constraint across taxonomic and developmental groups informs how limb cross-sections either allometrically or isometrically scale their form as they grow. These findings have direct implications to extant and extinct primate research pertaining to body mass estimation, functional morphology and behavioural ecology
    corecore