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arXiv 2018年

作者： Donner, Reik V. Stolbova, Veronika Balasis, Georgios Donges, Jonathan F. Georgiou, Marina Potirakis, Stelios M. Kurths, Jürgen Research Domain IV-Transdisciplinary Concepts and Methods Potsdam Germany Department of Physics Humboldt University Berlin Germany Department of Banking and Finance University of Zurich Switzerland Department of Control Theory Nizhny Novgorod State University Nizhny Novgorod Russia Institute for Astronomy Astrophysics Space Applications and Remote Sensing National Observatory of Athens Penteli Athens Greece Research Domain I-Earth System Analysis Potsdam Germany Stockholm Resilience Centre Stockholm University Stockholm Sweden Department of Physics Section of Astrophysics Astronomy and Mechanics National and Kapodistrian University of Athens Zografos Athens Greece Department of Space and Climate Physics University College London Dorking Surrey United Kingdom Aigaleo Athens Greece Institute for Complex Systems and Mathematical Biology University of Aberdeen Aberdeen United Kingdom

Magnetic storms constitute the most remarkable large-scale phenomena of nonlinear magnetospheric dynamics. Studying the dynamical organization of macroscopic variability in terms of geomagnetic activity index data by means of complexity measures provides a promising approach for identifying the underlying processes and associated time-scales. Here, we apply a suite of characteristics from recurrence quantification analysis (RQA) and recurrence network analysis (RNA) in order to unveil some key nonlinear features of the hourly Disturbance storm-time (Dst) index during periods with magnetic storms and such of normal variability. Our results demonstrate that recurrence-based measures can serve as excellent tracers for changes in the dynamical complexity along non-stationary records of geomagnetic activity. In particular, trapping time (characterizing the typical length of "laminar phases" in the observed dynamics) and recurrence network transitivity (associated with the number of the system's effective dynamical degrees of freedom) allow for a very good discrimination between magnetic storm and quiescence phases. In general, some RQA and RNA characteristics distinguish between storm and non-storm times equally well or even better than other previously considered nonlinear characteristics like Hurst exponent or symbolic dynamics based entropy concepts. Our results point to future potentials of recurrence characteristics for unveiling temporal changes in the dynamical complexity of the magnetosphere. Copyright © 2018, The Authors. All rights reserved.

关键词： Degrees of freedom (mechanics)

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Online Fault Detection and Diagnosis of In-Core Neutron Detectors Using Generalized Likelihood Ratio Method

Online Fault Detection and Diagnosis of In-Core Neutron Dete...

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作者： Vidya Sagar, Yellapu Mishra, A.K. Tiwari, A.P. Degweker, S.B. Homi Bhabha National Institute Anushaktinagar Mumbai400094 India Reactor Control Systems Design Section Bhabha Atomic Research Centre Trombay Mumbai400085 India Mathematical Physics and Reactor Theory Section Bhabha Atomic Research Centre Trombay Mumbai400085 India

Vanadium self-powered neutron detectors (VSPNDs) have been proposed to be used in the Advanced Heavy Water Reactor for flux mapping purposes. However, response of VSPNDs to neutron flux variations is slow, and they might also develop faults. This paper proposes a hybrid scheme for state estimation based on the Kalman filtering approach and fault detection, diagnosis, and correction based on the generalized likelihood ratio (GLR) method for VSPNDs. The Kalman filter estimates prompt neutron flux variations from the delayed signal of VSPND, while the GLR method analyzes the innovations to detect fault in VSPND. Subsequently, the scheme also corrects for the step changes in the measurement emanating from fault in VSPND. Performance of the proposed hybrid scheme has been evaluated from simulation of neutron flux variations occurring due to simultaneous movement of regulating rods and demand power variations. It is shown that the magnitude and time of occurrence of step change in signal due to the fault are effectively estimated, and thus the step change can be corrected online. © 1963-2012 IEEE.

关键词： Kalman filters

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26th Annual Computational Neuroscience Meeting (CNS*2017) of the Organization for Computational Neuroscience Antwerp, Belgium, July 15-20, 2017

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BMC NEUROSCIENCE 2017年第SUPPL 1期18卷 59-59页

作者： [Anonymous] Indiana University Purdue University Indianapolis Indianapolis IN 46032 USA Stark Neurosciences Research Institute Indiana University School of Medicine Indianapolis IN 46032 USA Department of Mathematics East Carolina University Greenville NC 27858 USA Jülich Supercomputing Centre Forschungszentrum Jülich 52425 Jülich Germany Future Systems Swiss National Supercomputing Centre 8092 Zurich Switzerland User Engagement and Support Swiss National Supercomputing Centre 6900 Lugano Switzerland Institut de Neurosciences des Systèmes Aix Marseille Univ 13005 Marseille France Simulation Lab Neuroscience Forschungszentrum Jülich Jülich Germany Department of Experimental Psychology Ghent University 9000 Ghent Belgium Donders Center for Cognitive Neuroimaging Radboud University 6525HR Nijmegen The Netherlands Department of Electrical Computer and Energy Engineering University of Colorado Boulder CO 80309 USA Department of Neurosurgery Johns Hopkins School of Medicine Baltimore MD 21287 USA Department of Neurology Johns Hopkins School of Medicine Baltimore MD 21287 USA Department of Otolaryngology Johns Hopkins School of Medicine Baltimore MD 21287 USA INSERM U968 Paris France Sorbonne Universités UPMC University Paris 06 UMR_S 968 Institut de la Vision Paris France CNRS UMR_7210 Paris France Department of Computer Architecture and Technology University of Granada (CITIC) Granada Spain Sorbonne Universités UPMC Univ Paris 06 INSERM CNRS Institut de la Vision Paris France Department of Adaptive Machine Systems Osaka University Osaka Japan Department of Computer Science University of Cergy-Pontoise Cergy-Pontoise France Department of Physics and Astronomy College of Charleston Charleston SC 29424 USA School of Physics Faculty of Science University of Sydney Sydney NSW 2006 Australia Center of Excellence for Integrative Brain Function Australian Research Council Sydney Australia Max Planck Institute for Human Cognitive and Brain Sciences Saxony Lei

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A simple adaptive scheme for indirect field orientation of an induction motor

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EUROPEAN TRANSACTIONS ON ELECTRICAL POWER 1997年第4期7卷 243-249页

作者： Branco, PJC [?]Paulo Jose da Costa Branco (1965) received the B.Sc. and M.Sc. degrees in Electrical Engineering from the Universidade Federal do Rio de Janeiro (UFRJ) Rio de Janeiro/Bnsil in 1988 and 1991 respectively. Since 1992 he has been an Assistant at the Department of Electrical and Computing Engineering Section of Electrical Machines and Power Electronics in the Instituto Superior Tecnico (I.S.T.). He is currently working toward the Ph.D. degree in Electrical Engineering in an application of fuzzy learning theory in the design of “intelligent” electromechanica1 systems. His majorfieldsof interest are Control of Electrical Drives mainly their rncdellization and control using fuzzy logic and neural networks energy conservation and non-linear dynamic systems. In April I992 he joined at Centro de Automictica of Universidade Tecnica de Lisboa (CAUTL) as a researchassistant and in 1993 joined to the Mechatronics Laboratory in the same university. (Instituto Superior TCcnico (I.S.T.) Department of Electrical and Computing Engineering. Section of Electrical Machines and Power Electronics Lisboflortugal Phone: +35 I 1/8417432 Fax: +3511/848 29 87 E-mail: pbranco@alfa.ist.utl.pt)

A self-adaptive scheme is described for automatically tracking the temperature and saturation-dependent rotor time constant T-r in indirect vector control. This method is based on a monitoring signal injected into the process. A cross-correlation function between the monitoring signal and the speed error indicates the T-r changes in direction (increase or decrease) and magnitude. The proposed identification algorithm presents unique characteristics: it does not use current or voltage sensors;it is not motor-parameter dependent;the amplitude of the monitoring signal can be reduced but with an increase on the speed-error sensibility to control interference in drive's performance and it works either on steady-and dynamic transient-state. it will need some load to operate but this condition is satisfied in all practical cases. Tests were conducted with a 1.2 kW four-quadrant AC drive. The adaptive indirect vector-control was implemented in a microcomputer with the motor supplied by a voltage-source inverter with current control using IGBT Experimental and simulated results using this adaptive digital scheme for different loads and values of model T-r(representing a detuned operation) are presented showing good performances.

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BioX ++ -Extended Learning control of Biotechnological Processes

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IFAC Proceedings Volumes 1993年第2期26卷 997-1000页

作者： K.D. Bettenhausen H. Tolle Section Control Systems Theory and Robotics Institute of Control Engineering Technical University of Darmstadt Darmstadi Germany

The technical use of biological or biochemical processes requires additionally to the biological preparation and process engineering an intelligent automatic control engineering whose performance characteristics excel the classical approaches. Most fermentations are operated in a phase-building batch mode, which does not allow a linearization of the not or only inexact known process model and the operation near one or several different working points. With Bio X + + an intelligent control system was successfully designed, whose fundamentals and extensions will be the contents of the article at hand

关键词： Biotechnology batch fermentations learning systems associative memories expert systems fuzzy systems

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Integration of Expert systems and Neural Networks for the control of Fermentation Processes

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IFAC Proceedings Volumes 1992年第2期25卷 379-382页

作者： S. Gehlen H. Tolle J. Kreuzig P. Friedl Technical University of Darmstadt Institute of Control Engineering Section Control Systems Theory and Robotics Londgraf-Georg-Str. 46100 Darmstadt Germany Technical University of Darmstadt Institute of Biochemistry Petersenstr. 22 6100 Darmstadt Germany

Expert systems and neural networks are new tools for the control of fermentation processes. With expert systems the fermentation plant and the process itself is modelled via a generalized, qualitative system description based on the experience of human experts. On the other hand neural networks and interpolating associative memories can learn the process behaviour directly by process observation. The paper at hand reports, how both control techniques can be combined for purposes like process supervision, modelling and optimization of biological plants.

关键词： Expert systems neural networks associative memories learning control fermentation processes biotechnology

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Computational Complexity of Path Planning Algorithms Based on Safe Triangles and Quadtree as Work Space Representations: A Comparison †

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IFAC Proceedings Volumes 1991年第9期24卷 277-281页

作者： Xiaozhao Mao Institute of Control Engineering Section Control Systems Theory and Robotics Technical University Darmstadt Schlossgraben 1 D-6100 Darmstadt Germany

Computational complexity of two path planning approaches for a two-dimensional (2D) work space is considered: The approach using safe triangles and the approach based on quadtree. The average cost of establishing work space representation, i.e. of building the safe triangles and the quadtree respectively, are estimated. Both approaches are simulated to plan paths for numerous work spaces with obstacles which are generated at random. The results of the simulation are summarized to show the expected behavior of each approach. Comparison based on analyses and simulation is presented.

关键词： Computational complexity path planning robotics space representation

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A three fingered, multijointed gripper for experimental use

A three fingered, multijointed gripper for experimental use

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1990 IEEE International Workshop on Intelligent Robots and systems, IROS 1990

作者： Paetsch, W. Kaneko, M. Technical University of Darmstadt Department of Control Engeneering Control Systems Theory and Robotics Section Germany Kyushu Institute of Technology Computer Science and System Engeneering Kawazu 680-4 Iizuka820 Japan

A three fingered, multijointed robot gripper for experimental use is presented. The mechanics as well as the control architecture are designed for this special purpose. The gripper system provides the basic means in terms of position and force control to perform experiments about grasping and object motion in a useful way. The gripper will be used to develop and evaluate different approaches of stable grasping and object manipulation. First results of the control of the gripper on joint level as well as the cartesian behaviour of the fingers and some results and experiences with first grasping and manipulation experiments using the presented system are reported. © 1990 Institute of Electrical and Electronics Engineers Inc.. All rights reserved.

关键词： Grippers

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A three fingered, multijointed gripper for experimental use

A three fingered, multijointed gripper for experimental use

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EEE International Workshop on Intelligent Robots and systems, Towards a New Frontier of Applications

作者： W. Paetsch M. Kaneko Department of Control Engeneering Control Systems Theory and Robotics Section Technical University of Darmstadt Germany Computer Science and System Engeneering Kyushu Institute of Technology Iizuka Japan

A three fingered, multijointed robot gripper for experimental use is presented. The mechanics as well as the control architecture is designed for this special purpose. The gripper system provides the basic means in terms of position and force control to perform experiments about grasping and object motion in a useful way. The gripper can be used to develop and evaluate different approaches of stable grasping and object manipulation. Results of the control of the gripper on joint level, the Cartesian behaviour of the fingers and some experiences with the grasping and manipulation experiments using the presented system are reported.< >

关键词： Grippers control systems Robot sensing systems Space technology Force control Fingers Orbital robotics Computational modeling Computer simulation Grasping

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On the design and simulation-based validation of an active compliance law for multi-arm robots

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Robotics and Autonomous systems 1989年第4期5卷 307-321页

作者： Bruhm, H. Deisenroth, J. Schädler, P. Technical University of Darmstadt Department of Control Engineering Control Systems Theory and Robotics Section Schloßgraben 1 Darmstadt6100 Germany

A special active compliance law is presented as the feedback element in a non-master/slave (i.e. symmetric) coordination strategy with explicit force distribution for robots with multiple cooperating arms. The method used to design the compliance controller comprise a structural design phase and dynamics design phase. The proposed controller structure simplifies the design problem as it maps the multivariate system onto two decoupled SISO loops with PI controllers describing internal and external compliance behavior. The conditions for the validity of this conceptual system model are discussed and the significance of task parameters such as grasp configuration, force distribution law and mechanical compliance values for the controller structure is explored. The dynamic behavior of internal and external compliance is determined in the second design phase by the choice of gain and integral action time of the respective controllers. An example shows the applicability of classical SISO control system design tools such as the root locus technique. The validity of the design method has been verified by means of the multi-arm robot simulation program MAROSIM, which is also presented in the paper. © 1989

关键词： controllers

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