702 research outputs found

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 324)

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    This bibliography lists 200 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during May, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 297)

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    This bibliography lists 89 reports, articles and other documents introduced into the NASA scientific and technical information system in April, 1987

    Small business innovation research. Abstracts of 1988 phase 1 awards

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    Non-proprietary proposal abstracts of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA are presented. Projects in the fields of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robots, computer sciences, information systems, data processing, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered

    Vision Based Robotic Grasping Tracking of a Moving Object

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    Real-time vision allows the direct steering of a robotic manipulator. In this thesis we use a stereo rig mounted on an industrial robot (ABB IRB-6/2) which gives us information about the end effector position of a second robot (ABB IRB-2000/3). This second robotic manipulator performs the task of tracking a moving object, which in our case is a rolling ball. The first concern of this project is to deal with the different kinds of problems occurring in such a system. After measuring the time-delays in our system we can establish the degree in which they effect it. We can then use these results for the actual control loop. More specifically a Kalman predictor scheme is implemented to produce estimates of coordinates for requested times, based on the time delay analysis. This Kalman predictor also helps us when we have lost track of either the robotic manipulator or the rolling ball. Finally we perform the actual experiment of tracking the rolling ball. The experimental setup consists of the two robots and the stereo rig mentioned above, as well as a metallic ball rolling on a metallic board. The IRB-6 is mounted with the stereo rig and is set in a pre-decided position to be able to observe the movement of the rolling ball throughout the whole of its course. The other robotic manipulator performs the task of tracking the rolling ball, using as feedback the data received from the stereo rig.</p

    Learning to reach and reaching to learn: a unified approach to path planning and reactive control through reinforcement learning

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    The next generation of intelligent robots will need to be able to plan reaches. Not just ballistic point to point reaches, but reaches around things such as the edge of a table, a nearby human, or any other known object in the robot’s workspace. Planning reaches may seem easy to us humans, because we do it so intuitively, but it has proven to be a challenging problem, which continues to limit the versatility of what robots can do today. In this document, I propose a novel intrinsically motivated RL system that draws on both Path/Motion Planning and Reactive Control. Through Reinforcement Learning, it tightly integrates these two previously disparate approaches to robotics. The RL system is evaluated on a task, which is as yet unsolved by roboticists in practice. That is to put the palm of the iCub humanoid robot on arbitrary target objects in its workspace, start- ing from arbitrary initial configurations. Such motions can be generated by planning, or searching the configuration space, but this typically results in some kind of trajectory, which must then be tracked by a separate controller, and such an approach offers a brit- tle runtime solution because it is inflexible. Purely reactive systems are robust to many problems that render a planned trajectory infeasible, but lacking the capacity to search, they tend to get stuck behind constraints, and therefore do not replace motion planners. The planner/controller proposed here is novel in that it deliberately plans reaches without the need to track trajectories. Instead, reaches are composed of sequences of reactive motion primitives, implemented by my Modular Behavioral Environment (MoBeE), which provides (fictitious) force control with reactive collision avoidance by way of a realtime kinematic/geometric model of the robot and its workspace. Thus, to the best of my knowledge, mine is the first reach planning approach to simultaneously offer the best of both the Path/Motion Planning and Reactive Control approaches. By controlling the real, physical robot directly, and feeling the influence of the con- straints imposed by MoBeE, the proposed system learns a stochastic model of the iCub’s configuration space. Then, the model is exploited as a multiple query path planner to find sensible pre-reach poses, from which to initiate reaching actions. Experiments show that the system can autonomously find practical reaches to target objects in workspace and offers excellent robustness to changes in the workspace configuration as well as noise in the robot’s sensory-motor apparatus

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 343)

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    This bibliography lists 125 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during January, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance
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