Publikationen BV: Bibliographie 2005 BibTeX
@inproceedings {INPROC-2005-81,
author = {V. Avrutin and M. Schanz},
title = {{On special Types of two- and three-parametric Bifurcations in piecewise-smooth dynamical Systems}},
booktitle = {Proc. of 4th WSEAS Int. Conf. on non-linear Analysis, non-linear Systems and Chaos NOLASC 2005},
editor = {V. Mladenov and N. Bardis and A. Slavova and S. Yordanova and V. Damgov},
address = {Sofia},
publisher = {n. a.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--7},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {The aim of this paper is to present a brief overview about a special kind of
two-parametric (or co-dimension two) bifurcations in piecewise-smooth dynamical
systems. The characteristic property of these bifurcations is, that at the
bifurcation point in a 2D parameter space an infinite number of bifurcation
curves intersect. Several types of these bifurcations are discussed.
Additionally, a new type of three parametric (or co-dimension three)
bifurcations is reported.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-81&engl=0}
}
@inproceedings {INPROC-2005-80,
author = {Mohamed Oubbati and Michael Schanz and Paul Levi},
title = {{Mobile Robot Motion using Neural Networks: An Overview}},
booktitle = {Autonome Mobile Systeme 2005 (AMS)},
editor = {P. Levi and Schanz M. and et. al},
address = {Berlin, Heidelberg, New York},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Informatik Aktuell},
pages = {303--309},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2005},
isbn = {978-3-540-30291-9},
keywords = {neural network, mobile robot control},
language = {Englisch},
cr-category = {I.2.8 Problem Solving, Control Methods, and Search},
contact = {Mohamed.Oubbati@informatik.uni-stuttgart.de Michael.Schanz@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {In this paper, we provide a summary of our recent results in motion control of
mobile robots using recurrent neural networks. The most important asociated
problems are discussed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-80&engl=0}
}
@inproceedings {INPROC-2005-79,
author = {V. Avrutin and A. Koch and R. Lafrenz and P. Levi and M. Schanz},
title = {{A Unified Architecture for the Control Software of a Robot Swarm: Design and Investigation Results}},
booktitle = {Autonome Mobile Systeme 2005 (AMS)},
editor = {P. Levi and Schanz M. and R. Lafrenz and V. Avrutin},
address = {Berlin, Heidelberg, New York},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Informatik Aktuell},
pages = {41--48},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2005},
isbn = {978-3-540-30291-9},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
contact = {Viktor.Avrutin@informatik.uni-stuttgart.de Michael.Schanz@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {In this work a unied approach for modeling of micro-robot swarms and for
development of the controlling software architecture for individual robots is
presented. The approach leads to swarm models with self-organized behavior and
re ects the complexity of the considered swarm scenarios. The application of
the presented approach is demonstrated by example scenarios with several
complexity levels. Additionally, some techniques for the investigation of the
phenomena of self-organization are discussed. These techniques allow for
instance the determination of areas in the parameter space, i.e. the parameter
settings leading to a specic aimed behavior. Through our simulation experiments
we demonstrated, that the hardware requirements for applications using real
micro-robots can be determined.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-79&engl=0}
}
@inproceedings {INPROC-2005-76,
author = {V. Avrutin and M. Schanz},
title = {{AnT 4.669 - A Tool for Simulating and Investigating dynamical Systems}},
booktitle = {Proc. of XXV Int. Conf. Dynamic Days Europe},
editor = {E. Sch{\"o}ll and K. L{\"u}dge},
address = {Berlin, Germany},
publisher = {n. n.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Europhysics Conference Series},
volume = {29 E},
pages = {101--102},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {A software package for the simulation and investigation of dynamical systems
called AnT 4.669 will be presented in this paper. Due to its flexible
architecture, the AnT 4.669 software package is able to cope with dynamical
systems belonging to various classes, such as ordinary and recurrent maps,
ordinary, delayed, functional and partial differential equations currently with
only one spatial component. Further supported classes are: coupled maps,
coupled ordinary and delayed differential equations lattices as well as hybrid
systems, stochastic systems and external data. Many investigation methods are
implemented in the AnT 4.669 software package, like for instance general
trajectory evaluations, basic statistics, period and region analysis,
calculation of bifurcation diagrams, spectral analysis, principal component
decomposition, symbolic sequence evaluation and the calculation of Lyapunov
exponents using two different algorithms. Additionally a generalized
implementation of Poincar{\'e} sections and Poincar{\'e} return maps exists, with
several pre-implemented conditions and an additional possibility with a user
defined condition. Furthermore, the box-counting based calculation of the
invariant measure, the entropy and several fractal dimensions are available.
Additionally, a collection of investigation methods based on the calculation of
the symbolic image of a dynamical system is implemented. Using these methods,
one is able to determine stable and unstable invariant sets, stable and
unstable manifolds of fixed points and periodic orbits, as well as basins of
attraction. For dynamical systems discrete in time, the calculation of backward
orbits is implemented.
Another important feature of the AnT 4.669 software package, is the capability
to perform so-called scan runs, that is the ability to investigate a dynamical
system by varying one, two or even more relevant influence quantities, such as
the control parameters, initial values, or even some parameters of the
investigation methods, which is interesting in the context of optimizing the
results obtained by an investigation method. When dealing with scans in
high-dimensional parameter and/or state spaces, a significant advantage of the
AnT 4.669 software package is the distributed computing capability. This
capability is based on a client/server architecture and allows the calculation
of time consuming scan runs on an arbitrary number of computing nodes (both, in
homogeneous clusters as well as in heterogeneous networks).
The AnT 4.669 software package possesses also an interactive visualization
module, based on the OpenGL standard, which supports animations of trajectories
and an intuitive graphical user front-end, that guides a user of the system
through the complex initialization phase of a simulation run.
Finally there exists a web front-end to the AnT computation engine, which
allows the remote execution of simulation runs.
AnT 4.669 is free software (published under the GPL) and is available for
several UNIX as well as Windows platforms. More information about the
AnT-project can be found on the website: www.AnT4669.de.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-76&engl=0}
}
@inproceedings {INPROC-2005-75,
author = {V. Avrutin and M. Schanz},
title = {{On multi-parametric Bifurcations in piecewise-smooth dynamical Systems}},
booktitle = {Proc. of XXV Int. Conf. Dynamic Days Europe},
editor = {E. Sch{\"o}ll and K. L{\"u}dge},
address = {Berlin, Germany},
publisher = {n. n.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Europhysics Conference Series},
volume = {29 E},
pages = {100--101},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {Dynamical systems with a discontinuous system function represent a central
topic of many scientific works published in the recent years. This research
area is motivated by several practical applications, ranging from power
electronic circuits (for instance DC/DC converters) to mechanical systems with
impact or stick-slip phenomena, as well as hybrid and relay controlled systems.
In the field of nonlinear dynamics 1D maps with a piecewise-smooth system
function are well-known as return maps, obtained by the investigation of
Poincar$\backslash$'e sections of dynamical systems continuous in time. The discontinuity
of these return maps is caused by the stretching, squeezing and folding
phenomena, which are inherent for chaotic attractors. This discontinuity
represents a border in the state space, which leads to the basic property of
piecewise-smooth dynamical systems, namely their ability to undergo
border-collision bifurcations.
Multi-parametric bifurcations (also known as co-dimension-\$n\$ bifurcations with
\$n$>$1\$) are bifurcations, which can be adequately described only in an
\$n\$-dimensional parameter space. The characteristic property of these
bifurcations is, that at these points a number \$m$>$1\$ of \$(n-1)\$-dimensional
bifurcation hyper-surfaces (for instance, curves for \$n=2\$) intersect each
other. The fundamental consequence of this property is, that a single
bifurcation point of this type can dominate the dynamic behavior of the
investigated system in a large area of the \$n\$-dimensional parameter space.
Until now these phenomena were mostly investigated for smooth dynamical
systems. Several types of these bifurcations are known, like cusps,
double-Hopf, Shilnikov-Hopf, etc., which are induced by simple local
bifurcations (saddle-node, Hopf). In piecewise-smooth dynamical systems,
multi-parametric bifurcations can be induced by border-collision bifurcations
as well. In this work, we investigate an important special case of such a
bifurcation, where the aforementioned number \$m\$ is infinite.
Therefore, a 1D dynamical system, discrete in time, with a single point of
discontinuity is considered. This map has \$3\$ parameters and represents some
kind of normal form for maps with discontinuous system function. The part of
the 3D parameter space, where this map shows periodic dynamics, is investigated
in detail. It is demonstrated, that the behavior of the investigated map is
determined by border collision bifurcations, whereby the areas in the parameter
space leading to specific limit cycles can be obtained analytically. The main
result of the presented work is a detailed description of the multi-parametric
bifurcations in the investigated piecewise-linear map. The complete structure
of the 3D parameter space is described, and it is shown, that the investigated
map shows not only the usual one-parametric bifurcations, but also an infinite
number of two-parametric bifurcations. Additionally, it is shown, that in the
investigated system a three-parametric bifurcation occurs. It turns out, that
the complete structure of the 3D parameter space is reflected in the structure
of an infinite small vicinity of this bifurcation point. In other words: the
complete structure of the 3D parameter space can be explained and described by
the investigation of the single point, where this three-parametric bifurcation
occurs.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-75&engl=0}
}
@inproceedings {INPROC-2005-64,
author = {T. Buchheim and U. K{\"a}ppeler and R. Lafrenz and M. Oubbati and H. Rajaie and M. Schanz and F. Schreiber and O. Zweigle and P. Levi},
title = {{Team Description Paper 2005 CoPS Stuttgart}},
booktitle = {RoboCup 2005},
address = {Osaka, Japan},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--2},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {n. n.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-64&engl=0}
}
@inproceedings {INPROC-2005-60,
author = {M. Schanz and J. Starke and R. Lafrenz and O. Zweigle and M. Oubbati and H. Rajaie and F. Schreiber and T. Buchheim and U. K{\"a}ppeler and P. Levi},
title = {{Dynamic Task Assignment in a Team of Agents}},
booktitle = {Autonome Mobile Systeme 2005 (AMS)},
editor = {P. Levi and Schanz M. and et. al},
address = {Berlin, Heidelberg, New York},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Informatik Aktuell},
pages = {11--18},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2005},
isbn = {978-3-540-30291-9},
keywords = {combinatorial optimization; self-organization; coupled-selection equations; autonomous systems; soccer playing robots},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
contact = {Michael.Schanz@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {In dynamic and complex multi-robot scenarios, the task assignment is a
challenging and crucial topic, because it has to be very exible and robust or
in some sense fault-tolerant to achieve a certain degree of redundancy which is
often required in these scenarios. To cope with these requirements, a dynamic
task assignment approach based on selforganization principles adopted from
nature is presented. In this work, a team of soccer playing robots is used to
validate the suggested selforganized dynamic task assignment in dynamic domains
with real-time constraints.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-60&engl=0}
}
@inproceedings {INPROC-2005-53,
author = {Kornienko and Kornienko and Levi},
title = {{Informationstechnologien f{\"u}r den Wandel}},
booktitle = {Wandlungsf{\"a}hige Unternehmensstrukturen},
editor = {E. Westk{\"a}mper and E. Zahn},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Das Stuttgarter Unternehmensmodell},
pages = {160--183},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Deutsch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {n. n.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-53&engl=0}
}
@inproceedings {INPROC-2005-52,
author = {S. Kornienko and O. Kornienko and P. Levi},
title = {{Minimalistic Approach towards Communication and Perception in Microrobotic Swarms}},
booktitle = {Proceedings of IROS 2005},
address = {Edmonton, Canada},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--2},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {n. n.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-52&engl=0}
}
@inproceedings {INPROC-2005-51,
author = {S. Kornienko and O. Kornienko and P. Levi},
title = {{Collective AI: Context-Awareness via Communication}},
booktitle = {Proceedings of the 19th European Conference on Artificial Intelligence (IJCAI)},
address = {Edinburgh, Great Britain},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--2},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {n. n.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-51&engl=0}
}
@inproceedings {INPROC-2005-47,
author = {M. Oubbati and M. Schanz and P. Levi},
title = {{Fixed-Weight RNN Adaptive Controller for an Omnidirectional Robot}},
booktitle = {Proceedings of the 9th International Conference on Engineering Applications of Neural Networks (EANN05)},
address = {Lille, France},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--2},
type = {Konferenz-Beitrag},
month = {August},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {n. n.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-47&engl=0}
}
@inproceedings {INPROC-2005-46,
author = {M. Oubbati and M. Schanz and Th. Buchheim and P. Levi},
title = {{Velocity Control of Omnidirectional RoboCup Player with Recurrent Neural Networks}},
booktitle = {Proceedings of the RoboCup Symposium},
address = {Osaka},
publisher = {n. n.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--2},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {n. n.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-46&engl=0}
}
@inproceedings {INPROC-2005-45,
author = {V. Avrutin and C. Constantinescu and A. Koch and M. Schanz and P. Levi},
title = {{Hierarchical Self-Organization in Swarms of Nano-Robots}},
booktitle = {Proceedings of the XXV Int. Conf. Of Dynamic Days Europe},
editor = {E. Sch{\"o}ll and K. L{\"u}dge},
address = {Berlin (TU Berlin), Germany},
publisher = {Europhysics Conference Series},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Europhysics Conference Series},
volume = {29 E},
pages = {272--273},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {The fundamental vision of modern nano-robotics is a swarm of micro-robots,
which is capable of performing tasks that are not possible with either a single
micro-robot, or even with a small group of micro-robots. Using principles of
artificial physics and self-organization for the control algorithms of such a
swarm of micro-robots, it is expected, that the swarm controlled in such a way
shows self-organized behavior similar to the self-organization phenomena
occurring in many biological or ecological systems like ant tribes, bee
colonies and other insect aggregations or flocking birds and shoals. There are
many potential benefits of such a system including greater flexibility and
adaptability to the environment, robustness to failures, compensation of
breakdowns from one or several units, etc.
In this work we describe a basic mathematical approach for modeling of the
swarm behavior and for developing the control software of individual
micro-robots. The approach is based on laws of artificial physics and coupled
hybrid automata. Designing the interaction patterns between robots, we are able
to achieve the desired self-organized behavior. For the modeling of these
interactions we use so-called virtual power functions (also known as social
powers). Depending on the complexity of the considered swarm scenarios,
specific classes of hybrid automata, namely degenerated, standard or
hierarchical ones, are used. In the last case complex swarm scenarios are
implemented using the concept of hierarchical self-organization. According to
this concept, the whole system consists of a hierarchy of subsystems. The most
simple subsystems (atomic entities, robots) build simple formations via a usual
self-organization process. In the presented approach these simple formations
are chains of robots with a pre-defined or variable length. Then the simple
formations operate as entities (non-atomic self-organized entities) and build
more complex formations via a self-organization process on the next hierarchy
level. Theoretically, the number of the self-organization levels in a
hierarchical self-organization process is not restricted, however in our
approach we restrict it firstly to two levels. This restriction is sufficient
in order to demonstrate the applicability of the presented concept and can be
extended in future work.
The application of the presented approach is demonstrated by example scenarios
with several complexity levels. Additionally, some techniques for the
investigation of the self-organization phenomena, applied from the fields of
coupled map lattices and hybrid systems, are discussed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-45&engl=0}
}
@inproceedings {INPROC-2005-44,
author = {V. Avrutin and P. Levi and M. Schanz},
title = {{Border-Collision induced Bifurcation Phenomena and multi-parametric Bifurcations in a piecewise-quadratic map on the Interval}},
booktitle = {Proceedings of Fifth EUROMECH Nonlinear Dynamics Conf. (ENOC'2005)},
address = {Eindhoven, NL},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {This article describes some bifurcation phenomena, induced by border-collisions
in a piecewise--quadratic map on interval representing a special kind of
Poincar{\'e} return map for dynamical systems of the Lorenz type. It is shown that
the structure of the 2D parameter space of this map is dominated by
singularities, which we denote as big bang bifurcation points. These
bifurcations can be observed only if two parameters are varied simultaneously
and cause an infinite number of different periodic dynamics. The investigated
system shows an infinite number of the big bang bifurcations, which lead to the
complex self-similar structure of the 2D parameter space.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-44&engl=0}
}
@inproceedings {INPROC-2005-35,
author = {Mohamed Oubbati and Schanz Michael and Paul Levi},
title = {{Kinematic and dynamic adaptive control of a nonholonomic mobile robot using a RNN}},
booktitle = {Proceedings of the 6th IEEE Symposium on Computational Intelligence in Robtics and Automation (CIRA05)},
address = {Helsinki, Finland},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {27--33},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2005},
keywords = {Nonholonomic mobile robots; adaptive control; recurrent neural networks; meta-learning},
language = {Englisch},
cr-category = {I.2.9 Robotics,
I.2 Artificial Intelligence},
contact = {Mohamed.Oubbati@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {In this paper, an adaptive neurocontrol system with two levels is proposed for
the motion control of a nonholonomic mobile robot. In the first level, a
recurrent network improves the robustness of a kinematic controller and
generates linear and angular velocities, necessary to track a reference
trajectory. In the second level, another network converts the desired
velocities, provided by the first level, into a torque control. The advantage
of the control approach is that, no knowledge about the dynamic model is
required, and no synaptic weight changing is needed in presence of parameters
variation. This capability is acquired through prior meta-learning. Simulation
results are demonstrated to validate the robustness of the proposed approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-35&engl=0}
}
@inproceedings {INPROC-2005-34,
author = {Mohamed Oubbati and Paul Levi and Michael Schanz},
title = {{Meta-learning for Adaptive Identification of Non-linear Dynamical Systems.}},
booktitle = {Proceedings of the Joint 20th IEEE International Symposium on Intelligent Control \& 13th Mediterranean Conference on Control and Automation (2005 ISIC-MED).},
address = {Limassol, Cyprus},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {473--478},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2005},
keywords = {Adaptive Identification; RNNs; Non-linear Dynamical Systems; Meta-learning.},
language = {Englisch},
cr-category = {I.2.8 Problem Solving, Control Methods, and Search},
contact = {Mohamed.Oubbati@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {Adaptive Identification of Non-linear Dynamical Systems via Recurrent Neural
Networks (RNNs) is presented in this paper. We explore the notion that a
fixed-weight RNN needs to change only its internal state to change its behavior
policy. This ability is acquired through prior training procedure that enable
the learning of adaptive behaviors. Some simulation results are presented.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-34&engl=0}
}
@inproceedings {INPROC-2005-20,
author = {Mohamed Oubbati and Paul Levi and Michael Schanz},
title = {{A Fixed-Weight RNN Dynamic Controller for Multiple Mobile Robots}},
booktitle = {Proceedings of the 24th IASTED International Conference on MODELLING, IDENTIFICATION, AND CONTROL: MIC 2005; Innsbruck, Austria, February 16-18, 2005.},
address = {Austria},
publisher = {ACTA Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {277--282},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2005},
keywords = {Mobile Robot; Recurrent Neural Networks, Meta-Learning; Adaptive Control},
language = {Englisch},
cr-category = {I.2.9 Robotics},
contact = {Mohamed.Oubbati@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {In this paper, we demonstrate the ability of a single fixed-weight RNN to act
as a dynamic controller for several (here 3) distinct wheeled mobile robots,
without exact knowledge about their dynamics parameters. The controller is
properly trained to exhibit adaptive behaviour after its weights have been
fixed. This capability is a natural consequence of prior meta-learning used
recently in the area of RNNs.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-20&engl=0}
}
@inproceedings {INPROC-2005-05,
author = {Uwe-Philipp K{\"a}ppeler and Georg Kindermann and Daniela Nicklas and Nicola H{\"o}nle and Dominique Dudkowski},
title = {{Shared Dynamic Context Models: Benefits for Advanced Sensor Data Fusion for Autonomous Robots}},
booktitle = {Proceedings of Artificial Intelligence and Applications 2005; Innsbruck, Austria, February, 14-16, 2005},
publisher = {IASTED},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2005},
keywords = {Autonomous; Robots; Sensor; Fusion; Nexus; Context; Sensorfusion},
language = {Englisch},
cr-category = {H.3.3 Information Search and Retrieval,
I.2.9 Robotics},
contact = {kaeppeler@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {Information provided by a shared dynamic context model offers new possibilities
in the realm of autonomous robots. The availability of external context
information can be used by a robot to extend and to validate the locally
acquired knowledge about its dynamic environment. A lot of helpful context
information is already available in digital form and its quantity will increase
rapidly, according to the vision of ubiquitous computing.
In this paper we present the Nexus Platform capable of managing a global
dynamic context model that can be addressed and accessed in an easy and uniform
way by all kinds of context-aware applications (like robots). Advantages for an
autonomous wheelchair robot using the Nexus Platform are depicted within an
airport scenario. We further present a framework for a sensor fusion agent,
able to perform multi-sensor data fusion with selective attention control,
concerning the current situation of the environment.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-05&engl=0}
}
@inproceedings {INPROC-2005-04,
author = {Nicola H{\"o}nle and Uwe-Philipp K{\"a}ppeler and Daniela Nicklas and Thomas Schwarz},
title = {{Benefits Of Integrating Meta Data Into A Context Model}},
booktitle = {Proceedings of 2nd IEEE PerCom Workshop on Context Modeling and Reasoning (CoMoRea) (at 3rd IEEE International Conference on Pervasive Computing and Communication (PerCom'05)); Hawaii, March 12, 2005},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2005},
keywords = {meta data; context model; context-aware applications},
language = {Englisch},
cr-category = {H.2.1 Database Management Logical Design},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {Meta data—data about data—improves the value of the operational data by giving
applications and users additional information on the data’s origin, its
precision or staleness. We outline the benefits of modeling meta data in
context models: it can be used for resource finding, enhanced data selection,
trust and data quality issues and sensor fusion. We show how meta data included
into an object-based context model influences the data modeling and the
selection process in the query language. Finally, we describe our
implementation of the presented functionality in the Nexus platform.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-04&engl=0}
}
@inproceedings {INPROC-2005-03,
author = {Matthias Grossmann and Martin Bauer and Nicola H{\"o}nle and Uwe-Philipp K{\"a}ppeler and Daniela Nicklas and Thomas Schwarz},
title = {{Efficiently Managing Context Information for Large-scale Scenarios}},
booktitle = {Proceedings of the 3rd IEEE Conference on Pervasive Computing and Communications: PerCom2005; Kauai Island, Hawaii, March 8-12, 2005},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2005},
language = {Englisch},
cr-category = {H.3.0 Information Storage and Retrieval General,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {matthias.grossmann@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we address the data management aspect of large-scale pervasive
computing systems. We aim at building an infrastructure that simultaneously
supports many kinds of context-aware applications, ranging from room level up
to nation level. This allembracing approach gives rise to synergetic benefits
like data reuse and sensor sharing. We identify major classes of context data
and detail on their characteristics relevant for efficiently managing large
amounts of it. Based on that, we argue that for large-scale systems it is
beneficial to have special-purpose servers that are optimized for managing a
certain class of context data. In the Nexus project we have implemented five
servers for different classes of context data and a very flexible federation
middleware integrating all these servers. For each of them, we highlight in
which way the requirements of the targeted class of data are tackled and
discuss our experiences.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-03&engl=0}
}
@article {ART-2005-10,
author = {J. Starke and T. Kaga and M. Schanz and T. Fukuda},
title = {{Experimental Study on Self-organized and Error Resistant Control of Distributed Autonomous Robotic Systems}},
journal = {The International Journal of Robotics Research},
publisher = {Sage Publications},
volume = {24},
number = {6},
pages = {465--486},
type = {Artikel in Zeitschrift},
month = {Juni},
year = {2005},
doi = {10.1177/0278364905053239},
keywords = {self-organization; selection equation; distributed robotic systems; assignment problem},
language = {Englisch},
cr-category = {I.2.9 Robotics,
G.1.6 Numerical Analysis Optimization,
G.2.1 Discrete Mathematics Combinatorics},
contact = {Michael.Schanz@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {The assignment of distributed mobile autonomous robots to targets, which occurs
for instance as an important task in flexible manufacturing environments, is
solved by using a self-organization approach motivated by pattern formation
principles in biological, chemical and physical systems. Similar to
observerations in many natural systems, like ant tribes, pattern formation of
coloured shells or convection patterns in the Rayleigh-B{\'e}nard problem of fluid
dynamics, the selforganization principles lead to a robust and fault tolerant
behaviour where the patterns or structures recover from disturbances. The
considered problem is the dynamic assignment of a number of robots to given
targets where the mobile robots have to move to the targets in order to perform
some tasks there. Hereby, each robot uses only local information, i.e., no
world coordinate system is necessary. The underlying mathematical problem of
the robot-target assignment is the so-called two-index assignment problem from
combinatorial optimization. The used approach guarantees always feasible
solutions in the assignment of robotic units to targets. As a consequence, for
scenarios with only convex obstacles with large enough distances to each other,
no spurious states cause the assignment process to fail. The error resistant
control method for distributed autonomous robotic systems is demonstrated by
several experiments with mobile robots. These results are compared and
supplemented with computer simulations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-10&engl=0}
}
@article {ART-2005-09,
author = {V. Avrutin and M. Schanz},
title = {{On special types of two- and three-parametric bifurcations in piecewise-smooth dynamical systems}},
journal = {WSEAS Transactions on Mathematics},
publisher = {WSEAS Press},
volume = {3},
number = {4},
pages = {224--230},
type = {Artikel in Zeitschrift},
month = {Juli},
year = {2005},
keywords = {multi-parametric bifurcations, big bang bifurcations, co-dimension two bifurcations, co-dimension three bifurcations, period increment, period adding, piecewise smooth systems},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
contact = {Michael.Schanz@informatik.uni-stuttgart.de Viktor.Avrutin@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {The aim of this paper is to present a brief overview about a special kind of
two-parametric (or co-dimension two) bifurcations in piecewise-smooth dynamical
systems. The characteristic property of these bifurcations is, that at the
bifurcation point in a 2D parameter space an infinite number of bifurcation
curves intersect. Several types of these bifurcations are discussed.
Additionally, a new type of three parametric (or co-dimension three)
bifurcations is reported.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-09&engl=0}
}
@article {ART-2005-04,
author = {Viktor Avrutin and Michael Schanz},
title = {{Period-doubling Scenario without Flip Bifurcations in a one-dimensional Map}},
journal = {International Journal of Bifurcation and Chaos},
publisher = {World Scientific Publishing Company},
volume = {15},
number = {4},
pages = {1267--1284},
type = {Artikel in Zeitschrift},
month = {April},
year = {2005},
doi = {10.1142/S0218127405012752},
keywords = {Period-doubling; border collision; piecewise-smooth vector field; kneading orbits},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications,
J.2 Physical Sciences and Engineering},
contact = {Michael.Schanz@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {In this work a one-dimensional piecewise-smooth dynamical system, representing
a Poincar{\'e} return map for dynamical systems of the Lorenz type, is
investigated. The system shows a bifurcation scenario similar to the classical
period-doubling one, but which is influenced by so-called border collision
phenomena and denoted as border collision period-doubling bifurcation scenario.
This scenario is formed by a sequence of pairs of bifurcations, whereby each
pair consists of a border collision bifurcation and a pitchfork bifurcation.
The mechanism leading to this scenario and its characteristic properties, like
symmetry-breaking and symmetry-recovering as well as emergence of coexisting
attractors, are investigated.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-04&engl=0}
}
@inbook {INBOOK-2005-03,
author = {V. Avrutin and M. Schanz and P. Levi},
title = {{AnT 4.669 - a tool for simulating and investigating dynamical systems}},
series = {Book of Abstracts},
address = {Berlin, Germany},
publisher = {European Physical Society},
series = {XXV Dynamics Days Europe 2005},
volume = {29 E},
pages = {1--2},
type = {Beitrag in Buch},
month = {Juli},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {A software package for the simulation and investigation of dynamical systems
called AnT 4.669 will be presented in this paper. Due to its flexible
architecture, the AnT 4.669 software package is able to cope with dynamical
systems belonging to various classes, such as ordinary and recurrent maps,
ordinary, delayed, functional and partial differential equations currently with
only one spatial component. Further supported classes are: coupled maps,
coupled ordinary and delayed differential equations lattices as well as hybrid
systems, stochastic systems and external data. Many investigation methods are
implemented in the AnT 4.669 software package, like for instance general
trajectory evaluations, basic statistics, period and region analysis,
calculation of bifurcation diagrams, spectral analysis, principal component
decomposition, symbolic sequence evaluation and the calculation of Lyapunov
exponents using two different algorithms. Additionally a generalized
implementation of Poincare sections and Poincare return maps exists, with
several pre-implemented conditions and an additional possibility with a user
defined condition. Furthermore, the box-counting based calculation of the
invariant measure, the entropy and several fractal dimensions are available.
Additionally, a collection of investigation methods based on the calculation of
the symbolic image of a dynamical system is implemented. Using these methods,
one is able to determine stable and unstable invariant sets, stable and
unstable manifolds of fixed points and periodic orbits, as well as basins of
attraction. For dynamical systems discrete in time, the calculation of backward
orbits is implemented.
Another important feature of the AnT 4.669 software package, is the capability
to perform so-called scan runs, that is the ability to investigate a dynamical
system by varying one, two or even more relevant influence quantities, such as
the control parameters, initial values, or even some parameters of the
investigation methods, which is interesting in the context of optimizing the
results obtained by an investigation method. When dealing with scans in
high-dimensional parameter and/or state spaces, a significant advantage of the
AnT 4.669 software package is the distributed computing capability. This
capability is based on a client/server architecture and allows the calculation
of time consuming scan runs on an arbitrary number of computing nodes (both, in
homogeneous clusters as well as in heterogeneous networks). The AnT 4.669
software package possesses also an interactive visualization module, based on
the OpenGL standard, which supports animations of trajectories and an intuitive
graphical user front-end, that guides a user of the system through the complex
initialization phase of a simulation run. Finally there exists a web front-end
to the AnT 4.669 computation engine, which allows the remote execution of
simulation runs.
AnT 4.669 is free software (published under the GPL) and is available for
several UNIX as well as Windows platforms. More information about the AnT
4.669-project can be found on the website: www.AnT4669.de.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2005-03&engl=0}
}
@inbook {INBOOK-2005-02,
author = {V. Avrutin and M. Schanz and P. Levi},
title = {{On multi-parametric bifurcations in piecewise-smooth dynamical systems}},
series = {Book of Abstracts},
address = {Berlin, Germany},
publisher = {European Physical Society},
series = {XXV Dynamics Days Europe 2005},
volume = {29 E},
pages = {25--28},
type = {Beitrag in Buch},
month = {Juli},
year = {2005},
language = {Englisch},
cr-category = {G.1.10 Numerical Analysis Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {Dynamical systems with a discontinuous system function represent a central
topic of many scientific works published in the recent years. This research
area is motivated by several practical applications, ranging from power
electronic circuits (for instance DC/DC converters) to mechanical systems with
impact or stick-slip phenomena, as well as hybrid and relay controlled systems.
In the field of nonlinear dynamics 1D maps with a piecewise-smooth system
function are well-known as return maps, obtained by the investigation of
Poincar{\'e} sections of dynamical systems continuous in time. The discontinuity of
these return maps is caused by the stretching, squeezing and folding phenomena,
which are inherent for chaotic attractors. This discontinuity represents a
border in the state space, which leads to the basic property of
piecewise-smooth dynamical systems, namely their ability to undergo
border-collision bifurcations.
Multi-parametric bifurcations (also known as co-dimension-n bifurcations with
n$>$1) are bifurcations, which can be adequately described only in an
n-dimensional parameter space. The characteristic property of these
bifurcations is, that at these points a number m$>$1 of (n-1)-dimensional
bifurcation hyper-surfaces (for instance, curves for n=2) intersect each other.
The fundamental consequence of this property is, that a single bifurcation
point of this type can dominate the dynamic behavior of the investigated system
in a large area of the n-dimensional parameter space. Until now these phenomena
were mostly investigated for smooth dynamical systems. Several types of these
bifurcations are known, like cusps, double-Hopf, Shilnikov-Hopf, etc., which
are induced by simple local bifurcations (saddle-node, Hopf). In
piecewise-smooth dynamical systems, multi-parametric bifurcations can be
induced by border-collision bifurcations as well. In this work, we investigate
an important special case of such a bifurcation, where the aforementioned
number m is infinite.
Therefore, a 1D dynamical system, discrete in time, with a single point of
discontinuity is considered. This map has 3 parameters and represents some kind
of normal form for maps with discontinuous system function. The part of the 3D
parameter space, where this map shows periodic dynamics, is investigated in
detail. It is demonstrated, that the behavior of the investigated map is
determined by border collision bifurcations, whereby the areas in the parameter
space leading to specific limit cycles can be obtained analytically. The main
result of the presented work is a detailed description of the multi-parametric
bifurcations in the investigated piecewise-linear map. The complete structure
of the 3D parameter space is described, and it is shown, that the investigated
map shows not only the usual one-parametric bifurcations, but also an infinite
number of two-parametric bifurcations. Additionally, it is shown, that in the
investigated system a three-parametric bifurcation occurs. It turns out, that
the complete structure of the 3D parameter space is reflected in the structure
of an infinite small vicinity of this bifurcation point. In other words: the
complete structure of the 3D parameter space can be explained and described by
the investigation of the single point, where this three-parametric bifurcation
occurs.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2005-02&engl=0}
}
@proceedings {PROC-2005-01,
editor = {Paul Levi and Michael Schanz},
title = {{Autonome Mobile Systeme 2005}},
address = {Berlin, Heidelberg, New York},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Informatik Aktuell},
pages = {332},
type = {Tagungsband},
month = {Dezember},
year = {2005},
isbn = {978-3-540-30291-9},
keywords = {Autonome Mobile Systeme},
language = {Deutsch},
cr-category = {I.2.9 Robotics,
I.2.10 Vision and Scene Understanding,
I.2.11 Distributed Artificial Intelligence,
I.4.7 Image Processing and Computer Vision Feature Measurement,
I.4.8 Image Processing and Computer Vision Scene Analysis,
I.5.4 Pattern Recognition Applications,
J.7 Computers in Other Systems},
contact = {Michael.Schanz@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {Die Fachgespr{\"a}che Autonome Mobile Systeme (AMS) repr{\"a}sentieren ein Forum, in
dem die neuesten Entwicklungen auf dem Gebiet wissenschaftlicher und
industrieller autonomer Robotersysteme, sowie verwandter Gebiete vorgestellt
werden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=PROC-2005-01&engl=0}
}
