28 research outputs found

    AIBA: An AI Model for Behavior Arbitration in Autonomous Driving

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    Driving in dynamically changing traffic is a highly challenging task for autonomous vehicles, especially in crowded urban roadways. The Artificial Intelligence (AI) system of a driverless car must be able to arbitrate between different driving strategies in order to properly plan the car's path, based on an understandable traffic scene model. In this paper, an AI behavior arbitration algorithm for Autonomous Driving (AD) is proposed. The method, coined AIBA (AI Behavior Arbitration), has been developed in two stages: (i) human driving scene description and understanding and (ii) formal modelling. The description of the scene is achieved by mimicking a human cognition model, while the modelling part is based on a formal representation which approximates the human driver understanding process. The advantage of the formal representation is that the functional safety of the system can be analytically inferred. The performance of the algorithm has been evaluated in Virtual Test Drive (VTD), a comprehensive traffic simulator, and in GridSim, a vehicle kinematics engine for prototypes.Comment: 12 page

    Mid-infrared interferometry with K band fringe-tracking I. The VLTI MIDI+FSU experiment

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    Context: A turbulent atmosphere causes atmospheric piston variations leading to rapid changes in the optical path difference of an interferometer, which causes correlated flux losses. This leads to decreased sensitivity and accuracy in the correlated flux measurement. Aims: To stabilize the N band interferometric signal in MIDI (MID-infrared Interferometric instrument), we use an external fringe tracker working in K band, the so-called FSU-A (fringe sensor unit) of the PRIMA (Phase-Referenced Imaging and Micro-arcsecond Astrometry) facility at VLTI. We present measurements obtained using the newly commissioned and publicly offered MIDI+FSU-A mode. A first characterization of the fringe-tracking performance and resulting gains in the N band are presented. In addition, we demonstrate the possibility of using the FSU-A to measure visibilities in the K band. Methods: We analyzed FSU-A fringe track data of 43 individual observations covering different baselines and object K band magnitudes with respect to the fringe-tracking performance. The N band group delay and phase delay values could be predicted by computing the relative change in the differential water vapor column density from FSU-A data. Visibility measurements in the K band were carried out using a scanning mode of the FSU-A. Results: Using the FSU-A K band group delay and phase delay measurements, we were able to predict the corresponding N band values with high accuracy with residuals of less than 1 micrometer. This allows the coherent integration of the MIDI fringes of faint or resolved N band targets, respectively. With that method we could decrease the detection limit of correlated fluxes of MIDI down to 0.5 Jy (vs. 5 Jy without FSU-A) and 0.05 Jy (vs. 0.2 Jy without FSU-A) using the ATs and UTs, respectively. The K band visibilities could be measured with a precision down to ~2%.Comment: 11 pages, 13 figures, Accepted for publication in A&

    An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status

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    MATISSE is the second-generation mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric instrument will allow significant advances by opening new avenues in various fundamental research fields: studying the planet-forming region of disks around young stellar objects, understanding the surface structures and mass loss phenomena affecting evolved stars, and probing the environments of black holes in active galactic nuclei. As a first breakthrough, MATISSE will enlarge the spectral domain of current optical interferometers by offering the L and M bands in addition to the N band. This will open a wide wavelength domain, ranging from 2.8 to 13 um, exploring angular scales as small as 3 mas (L band) / 10 mas (N band). As a second breakthrough, MATISSE will allow mid-infrared imaging - closure-phase aperture-synthesis imaging - with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. Moreover, MATISSE will offer a spectral resolution range from R ~ 30 to R ~ 5000. Here, we present one of the main science objectives, the study of protoplanetary disks, that has driven the instrument design and motivated several VLTI upgrades (GRA4MAT and NAOMI). We introduce the physical concept of MATISSE including a description of the signal on the detectors and an evaluation of the expected performances. We also discuss the current status of the MATISSE instrument, which is entering its testing phase, and the foreseen schedule for the next two years that will lead to the first light at Paranal.Comment: SPIE Astronomical Telescopes and Instrumentation conference, June 2016, 11 pages, 6 Figure

    The Return of the Mid-infrared to the VLT: News from the VISIR Upgrade

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    The VLT mid-infrared imager and spectrometer VISIR returns to science operations following an extended upgrade period. Among the most important modifications are: the imaging and spectroscopic detectors have been replaced with larger AQUARIUS (1024 by 1024 pixel) detector arrays; the N-band low-resolution grating has been exchanged; and support is now provided for precipitable water vapour monitoring, in order to select the best observing conditions. The AQUARIUS detectors stem from a development for very low background applications which result in excess noise under ground-based conditions. A series of interventions was needed to find a scheme that effectively exploits these detectors for ground-based use, involving the implementation of faster chopping. VISIR has been returned to service at the VLT with enhanced capabilities

    First light for GRAVITY: Phase referencing optical interferometry for the Very Large Telescope Interferometer

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    MATISSE, the VLTI mid-infrared imaging spectro-interferometer

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    GalaxiesStars and planetary systemsInstrumentatio

    Mid-infrared circumstellar emission of the long-period Cepheid l Carinae resolved with VLTI/MATISSE

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    Stars and planetary system

    Research on the ACC Autonomous Car

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    The aim of this paper is to present a general view about the autonomous driving researches made in the University of Applied Science Heilbronn, Germany. More exactly we will present aspects about our autonomous car design and construction. We will point out the original elements of our achievements: the driving robot construction and the control system structure design. This will be also the occasion to focus on the tactical level of the mentioned control system in order to present results on the trajectory tracking strategies

    Sensitivity Analysis of Fuzzy Signatures Using Minkowski’s Inequality

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