13 research outputs found

    (A) Vision for 2050 - Context-Based Image Understanding for a Human-Robot Soccer Match

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    We believe it is possible to create the visual subsystem needed for the RoboCup 2050 challenge - a soccer match between humans and robots - within the next decade.  In this position paper, we argue, that the basic techniques are available, but the main challenge will be to achieve the necessary robustness. We propose to address this challenge through the use of probabilistically modeled context, so for instance a visually indistinct circle is  accepted as the ball, if it fits well with the ball's motion model and vice versa.Our vision is accompanied by a sequence of (partially already conducted) experiments for its verification.  In these experiments, a human soccer player carries a helmet with a camera and an inertial sensor and the vision system has to extract all information from that data, a humanoid robot would need to take the human's place

    The long memory of the efficient market

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    For the London Stock Exchange we demonstrate that the signs of orders obey a long-memory process. The autocorrelation function decays roughly as τα\tau^{-\alpha} with α0.6\alpha \approx 0.6, corresponding to a Hurst exponent H0.7H \approx 0.7. This implies that the signs of future orders are quite predictable from the signs of past orders; all else being equal, this would suggest a very strong market inefficiency. We demonstrate, however, that fluctuations in order signs are compensated for by anti-correlated fluctuations in transaction size and liquidity, which are also long-memory processes. This tends to make the returns whiter. We show that some institutions display long-range memory and others don't

    Rapid Calibration of a Multi-Sensorial Humanoid's Upper Body: An Automatic and Self-Contained Approach

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    This paper addresses the problem of calibrating a pair of cameras, a Microsoft Kinect sensor and an inertial measurement unit (IMU) mounted at the head of a humanoid robot with respect to its kinematic chain. As complex manipulation tasks require an accurate interplay of all involved sensors, the quality of calibration is crucial for the outcome of the intended tasks. Typical procedures for calibrating are often time-consuming, involve multiple people overseeing a series of subsequent calibration steps and require external tools. We therefore propose to auto-calibrate all sensors in a single, completely automatic and self-contained procedure, i.e. without a calibration plate. By automatically detecting a single point feature on each wrist while moving the robot’s head, the stereo cameras’, the Kinect’s infrared camera’s intrinsic and extrinsic and an IMU’s extrinsic parameters are calibrated while considering the arm joint elasticities and joint angle offsets. All parameters are obtained by formulating the calibration problem as a single least-squares batch-optimization problem. The procedure is integrated on DLR’s humanoid robot Agile Justin allowing to obtain an accurate calibration in around 5 minutes by simply “pushing a button”. The proposed approach is experimentally validated by means of standard metrics of the calibration errors. </jats:p

    SSLvision: The shared vision system for the RoboCup Small Size League

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    Abstract. The current RoboCup Small Size League rules allow every team to set up their own global vision system as a primary sensor. This option, which is used by all participating teams, bears several organizational limitations and thus impairs the league’s progress. Additionally, most teams have converged on very similar solutions, and have produced only few significant research results to this global vision problem over the last years. Hence the responsible committees decided to migrate to a shared vision system (including also sharing the vision hardware) for all teams by 2010. This system – named SSL-Vision – is currently developed by volunteers from participating teams. In this paper, we describe the current state of SSL-Vision, i. e. its software architecture as well as the approaches used for image processing and camera calibration, together with the intended process for its introduction and its use beyond the scope of the Small Size League.
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