@inproceedings {INPROC-2007-75, author = {Oliver Zweigle and Uwe-Philipp K{\"a}ppeler and Thomas R{\"u}hr and Kai H{\"a}u{\ss}ermann and Reinhard Lafrenz and Frank Schreiber and Andreas Tamke and Hamid Rajaie and Avinash Burla and Michael Schanz and Paul Levi}, title = {{CoPS Stuttgart Team Description 2007}}, booktitle = {Proceedings of the RoboCup International Symposium; Atlanta, Georgia, July 9-10, 2007}, address = {Atlanta}, publisher = {RoboCup Organization}, institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany}, pages = {1--8}, type = {Conference Paper}, month = {July}, year = {2007}, keywords = {Robot soccer}, language = {English}, cr-category = {I.2.9 Robotics, I.2.10 Vision and Scene Understanding, I.2.11 Distributed Artificial Intelligence, I.2 Artificial Intelligence}, ee = {http://robocup.informatik.uni-stuttgart.de/, www.robocup.org}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {The CoPS robot soccer team is used as a testbed for multiagent software architecture principles in dynamic real time domains. The current research activities focus on reliable fast communication, situation recognition, communication and reliable ball detection.}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-75&engl=1} } @inproceedings {INPROC-2007-56, author = {Hamid Rajaie and Reinhard Lafrenz and Oliver Zweigle and Uwe-Philipp K{\"a}ppeler and Frank Schreiber and Thomas R{\"u}hr and Andreas Tamke and Paul Levi}, title = {{Physical Simulation of the Dynamical Behavior of Three-wheeled Omni-directional Robots}}, booktitle = {RoboCup International Symposium 2007, Atlanta, Georgia}, editor = {Ubbo Visser and Fernando Ribeiro and Frank Dellaert and Takashi Ohashi}, publisher = {CD-Proceedings}, institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany}, pages = {1--12}, type = {Conference Paper}, month = {July}, year = {2007}, keywords = {RoboCup, Simulation}, language = {English}, cr-category = {I.2.9 Robotics}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {Hardware simulation is a very e{\"\i}¬ƒcient way for parameter tuning. We developed a Simulink-based simulator for the navigation components of our robotic soccer team. This physical simulation has interfaces to be interconnected with the higher levels of the real control software and is therefore able to perform an overall simulation of single robots.}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-56&engl=1} } @inproceedings {INPROC-2007-47, author = {Reinhard Lafrenz and Frank Schreiber and Oliver Zweigle and Michael Schanz and Hamid Rajaie and Uwe-Philipp K{\"a}ppeler and Paul Levi and Jens Starke}, title = {{Evaluating coupled selection equations for dynamic task assignment using a behavior framework}}, booktitle = {Autonome Mobile Systeme 2007}, editor = {K. Berns and T. Luksch}, address = {Berlin,Heidelberg}, publisher = {Springer-Verlag}, institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany}, series = {Informatik Aktuell}, pages = {118--125}, type = {Conference Paper}, month = {October}, year = {2007}, isbn = {978-3-540-74763-5}, issn = {1431-472-X}, language = {English}, cr-category = {I.2.9 Robotics, I.2.11 Distributed Artificial Intelligence}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {In this paper we focus on methods for a reliable and robust mechanism to distribute roles among a team of cooperating robots. In previous work, we showed the principal applicability of a novel approach based on self organization using coupled selection equations. To show the applicability in the robocup scenario we used a simple scenario to assign the roles attacker and defender. In this paper we present the application of the novel approach to more realistic and complex scenarios like kick-off or pass play. One of the critical parts in this method is the parameterization of utility and activation functions used to determine the additional parameters.}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-47&engl=1} } @inproceedings {INPROC-2007-17, author = {Norbert Oswald and Andr{\'e} Windisch and Stefan Stefan F{\"o}rster and Herwig Moser and Toni Reichelt}, title = {{A Service-oriented Framework for Manned and Unmanned Systems to Support Network-centric Operations}}}, booktitle = {Proceedings of the Fourth International Conference on Informatics in Control, Automation and Robotics}, editor = {Control and Communication (INSTICC) Institute for Systems and Technologies of Information}, address = {Angers, France}, publisher = {INSTICC Press}, institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany}, pages = {284--291}, type = {Conference Paper}, month = {May}, year = {2007}, isbn = {978-972-8865-82-5}, keywords = {network-centricity, infrastructure for unmanned autonomous air vehicles}, language = {English}, cr-category = {I.2.9 Robotics, J.7 Computers in Other Systems}, contact = {Norbert.Oswald@eads.com}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {Network-centricity and autonomy are two buzzwords that have found increasing attention since the beginning of this decade in both, the military and civil domain. Although various conceptions exist of which capabilities are required for a system to be considered network-centric or autonomous, there can hardly be found proposals or prototypes that describe concrete transformations for both capabilities into software. The presented paper reviews work accomplished at EADS Military Air Systems driven by the need to develop an infrastructure that supports the realisation of both concepts in software with respect to traditional and modern software engineering principles, e.g., re-use and service-oriented development. This infrastructure is provided in form of a prototypical framework, accompanied by configuration and monitoring tools. Tests in a complex scenario requiring network-centricity and autonomy have shown that a significant technical readiness level can be reached by using the framework for mission software development.}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-17&engl=1} } @inproceedings {INPROC-2007-102, author = {Michael Schanz and Viktor Avrutin}, title = {{On some generic types of discontinuity induced codimension-3 bifurcations.}}, booktitle = {Abstracts for ICIAM 07}, publisher = {Online}, institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany}, pages = {312--312}, type = {Conference Paper}, month = {July}, year = {2007}, language = {English}, cr-category = {G.1.10 Numerical Analysis Applications}, contact = {Michael.Schanz@informatik.uni-stuttgart.de Viktor.Avrutin@informatik.uni-stuttgart.de}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {In this work we consider two families of piecewise-linear maps with a discontinuity, which is motivated by modeling of several power electronic circuits (DC/DC converters, Sigma-Delta modulators) and which is already investigated by many authors. However, the focus of these works lie on the investigation of the dynamics by variation of one or at most two system parameters. In many of these publications a great variety of bifurcation phenomena is revealed but unfortunately, a profound explanation of the complicated and often self-similar bifurcation structures and the systematics behind is missing. In contrast to that, we investigate the full 3D parameter space of these families of systems and detect a number of discontinuity induced codimension-3 bifurcations. Some of them belong to an already known generic type [1,2], while others represent some new types not investigated so far. Unfolding these bifurcations we are able to explain the systematics for a large number of the above mentioned bifurcation phenomena. In particular, several bifurcation scenarios observed under variation of one or two parameters represent an intersection of the extended bifurcation structures induced by codimension-3 bifurcation with the corresponding 1D or 2D parameter subspace. The codimension-3 bifurcations reported here are characterized by two manifolds in the 3D parameter space, a 1D and a 2D one. The 1D manifold represents a codimension-2 bifurcation curve, whereas in the 2D manifold an infinite number of codimension-2 bifurcation curves are located. At the codimension-3 bifurcation point all these curves intersect. The reported bifurcations serve as organizing centers of periodic and aperiodic dynamics in the overall parameter space. [1] V. Avrutin and M. Schanz, Nonlinearity 19, 531 (2006). [2] V. Avrutin, M. Schanz, and S. Banerjee, Nonlinearity 19, 1875 (2006).}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-102&engl=1} } @inproceedings {INPROC-2007-101, author = {Viktor Avrutin and Michael Schanz}, title = {{On the bandcount adding bifurcation scenario.}}, booktitle = {Abstracts for ICIAM07}, publisher = {Online}, institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany}, pages = {312--312}, type = {Conference Paper}, month = {July}, year = {2007}, language = {English}, cr-category = {G.1.10 Numerical Analysis Applications}, contact = {Michael.Schanz@informatik.uni-stuttgart.de Viktor.Avrutin@informatik.uni-stuttgart.de}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {An aperiodic and especially a chaotic attractor may consist of some number K $>$= 1 of bands (also denoted as connected components). Multi-band chaotic attractors (MBCAs) defined by the bandcount K $>$ 1, represent a well-known phenomenon on the field of nonlinear dynamics and are often involved in several bifurcations. It is for instance well-known, that the period doubling cascade is typically followed by an inverse band merging cascade, which represents a sequence of MBCAs with p0 2^n bands, whereby n decreases from infinity to zero. We report a novel bifurcation scenario (bandcount adding scenario), which involves an infinite number of MBCAs organized not sequentially, but according to an infinite adding scheme. This adding scheme which is similar to the well-known Farey-trees, implies that between two MBCAs with bandcounts K1 and K2 there is an MBCA with K1 + K2 - K0 bands (with some constant offset K0). This scenario continues ad infinitum and resembles the period adding scenario known from many applications, but in contrast to this is formed by chaotic and not by periodic attractors. We study this scenario using a discontinuous map, which is actually considered by many authors as some kind of normal form of the discrete-time representation of many non-smooth systems of practical interest in the neighborhood of the point of discontinuity. By investigation of the structure of the 2D parameter space, we find out, that the bandcount adding scenario is related with discontinuityinduced codimension-1 bifurcations of unstable periodic orbits and with some specific discontinuity-induced codimension-2 bifurcations. Consequently, we describe the self-similarity of the chaotic area in parameter space and show, that in this area there are much more non-robust chaotic attractors than typically assumed.}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-101&engl=1} } @article {ART-2007-04, author = {Viktor Avrutin and Michael Schanz and Soumitro Banerjee}, title = {{Codimension-3 bifurcations: Explanation of the complex 1-, 2- and 3D bifurcation structures in nonsmooth maps}}, journal = {Physical Review E}, publisher = {American Physical Society (APS)}, volume = {75}, number = {6}, pages = {1--7}, type = {Article in Journal}, month = {June}, year = {2007}, doi = {10.1103/PhysRevE.75.066205}, keywords = {discontinuity induced bifurcations; big bang bifurcations; period adding; period increment}, language = {English}, cr-category = {J.2 Physical Sciences and Engineering}, ee = {http://link.aps.org/abstract/PRE/v75/e066205}, contact = {Viktor.Avrutin@informatik.uni-stuttgart.de Michael.Schanz@informatik.uni-stuttgart.de}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {Many physical and engineerings systems exhibit cascades of periodic attractors arranged in period increment and period adding sequences as a parameter is varied. Such systems have been found to yield piecewise smooth maps, and in some cases the obtained map is discontinuous. By investigating the normal form of such maps, we have detected a new type of codimension-3 bifurcation which serves as the organizing center of periodic and aperiodic dynamics in the parameter space. The results will help in understanding the occurrence and structure of such cascades observed in many nonsmooth systems in science and engineering.}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2007-04&engl=1} } @article {ART-2007-03, author = {Viktor Avrutin and Bernd Eckstein and Michael Schanz}, title = {{On detection of multi-band chaotic attractors}}, journal = {Proceedings of the Royal Society A}, publisher = {The Royal Society}, volume = {463}, number = {2081}, pages = {1339--1358}, type = {Article in Journal}, month = {March}, year = {2007}, doi = {10.1098/rspa.2007.1826}, keywords = {multi-band chaotic attractors; discontinuous maps; bandcount adding}, language = {English}, cr-category = {G.1.0 Numerical Analysis General, G.4 Mathematical Software, J.2 Physical Sciences and Engineering}, contact = {Michael.Schanz@informatik.uni-stuttgart.de Viktor.Avrutin@informatik.uni-stuttgart.de}, department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding}, abstract = {In this work we present two numerical methods for the detection of the number of bands of a multi-band chaotic attractor. The first method is more efficient but can be applied only for dynamical systems with a continuous system function, whereas the second one is applicable for dynamical systems with a discontinuous system function as well. Using the developed methods, we investigate a 1D piecewise-linear map and report for both cases of a continuous and a discontinuous system function some new bifurcation scenarios involving multi-band chaotic attractors.}, url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2007-03&engl=1} }