2008:RoboCup-TDP-GermanTeam, cirpicme:2008, pmi:2008, wtonline2008, 2008-Kropf-etal-MMULATOR, 2008:RCS-BeckerRisler, 2008:Robotik2008-Klugetal, robotik2008_ptw_sim, 2008:RislervonStryk, 2008:ReinlRuhStolzenburgStryk, 2007:InsectMimetics-Moehl-etal, 2008:StelzervonStryk, 2008:IJHR-Friedmann-etal, 2007:OptEng-HemkerFowlervonStryk, 2008:IJRR-Hemkeretal, 2008:IJRR-Seyfarthetal, 2007:RCS-FriedmannPetersenvonStryk, 2007:RCS-JuengelRisler, 2007:FriedmannPetersenVonStryk_WsHumSoc, 2007:RoboCup-TDP-GermanTeam, hemker_et_al_2008, 2007:IROS-WS-Architectures-PettersThomasvonStryk, 2007:ReinlVonStryk_RoboMat, 2007:AMS-Friedmannetal, 2007:IROS-Kiener-vonStryk, 2007:ReinlVonStryk_ROBOCOMM, 2007:RoboCup-TDP-Dribblers, 2007:Compumag-Hemkeretal, 2007:AIM-Kratzetal, biomed:2006, icmmb:2006, 2006:HumanoidsSoccerWS-DarmstadtDribblersandHajimeTeam, 2006:ROBIO-Friedmannetal, 2006:ROBIO-Kratzetal, 2006:ZAMM_Stelzer_vonStryk, 2006:BionikGothavonStryk, 2006:IROSLoetzschRislerJuengel, 2006:IFAC-MVS-Friedmann-etal, 2006:IFAC-MVS-GlockerReinlvonStryk, 2006:CLAWARHemkeretal, 2006:CLAWARSeyfarthetal, 2006:IFACKratzStelzervStryk, 2006:MoehlvonStryk-Bionikbuch, 2006_hemker_CMWR, 2006:ACTUATORKratzStelzervonStryk, 2006BioRob:KlugvonStrykMoehl, MATHMOD2006, 2006_hemker_CEM, 2005:SpringerVideoRettig-etal, ASIM:2005, 2005:GlockerMartinvonStryk, 2005:ButzEhmann, kiener05, StelzervonStryk2005, RettigvonStryk:2005, RoefervonStryk:2005, ButzStryk:2005, 2005AMAM:KlugMoehlvonStrykBart, AMAM2005, DD:2005, KlugMoehlvonStrykBarth:2005, tropea:bionik2004, MechRob:2004, HoeplerStelzervonStryk:2004, Kiener:2004, DD:2004, GT:2004, Glocker:04, Butz-etal:2004, BussHardtetal.Humanoids:2003, ZulaufKieferEffenberger:2003, wollherr:aim03, vonStryk:Habil, GT:2003, PAMM:2003, ICRA:2003, RC:2002, GTTDP:2003, VoegelvonStrykBulirschWolterChucholowski2003, StelzerHardtvonStryk2003, HardtvonStryk2003, IFAC:2002, GlockervonStryk:2002, LNCSE:2002, ZAMM:2002, TF:2002-2, BussHardtvonStryk:2002, KONDISK:2002, IROS:2002, hardt:clawar02, TF:2002, GT:2002, vonStrykGlocker:2001, ISNM:2001, CACE:2001, LNCSE:2001, LNAI:2002, AISDG:2001, GT:2001, LNCSE:2001-2, vonStrykGlocker:2000, LAM:2000, HeimvonStryk:2000, CLAWAR:2000, LNCS:2000, SIAM:2000, BussvonStrykBulirschSchmidt:2000, DIRCOL, vonStrykVoegel:1999, vonStryk-CCG:1999, LNCSE:1999-2, LNCSE:1999, vonStryk:1998, KoslikRillvonStrykZampieri:1998, HeimvonStryketal:1996, BreitnerRettigvonStryk:1997, AnzillvonStryk:1994, HeimvonStryk:1996, AnzillvonStrykBulirschRusser:1994, BreitnerKoslikvonStrykPesch:1994, 1994:vonStrykDISSVDI, vonStrykSchlemmer:1993, vonStryk:1994, KiehlvonStryk:1994, vonStrykPeschBulirsch:1993, vonStryk:1993, BreitnerKoslikvonStrykPesch:1993, BulirschNerzPeschvonStryk:1991, vonStrykBulirsch:1992, KiehlvonStryk:1992,
@INCOLLECTION{2007:InsectMimetics-Moehl-etal,
author = {B. Möhl and S. Klug and T. Lens and O. von Stryk},
title = {Elasticity in insect wings: applications to compliant robot joints (in Japanese)},
year = {2008},
pages = {submitted},
publisher = {tba},
editor = {M. Matsukaze},
booktitle = {Insect Mimetics (in Japanese)},
}
@ARTICLE{2007:OptEng-HemkerFowlervonStryk,
author = {T. Hemker and K.R. Fowler and M.W. Farthing and O. von Stryk},
title = {A mixed-integer simulation-based optimization approach with surrogate functions in water resources management},
journal = {Optimization and Engineering},
year = {2008},
pages = {to appear},
doi = {10.1007/s11081-008-9048-0},
}
@INPROCEEDINGS{2007:RCS-FriedmannPetersenvonStryk,
author = {M. Friedmann and K. Petersen and O. von Stryk},
title = {Tailored real-time simulation for teams of humanoid robots},
year = {2008},
volume = {5001},
pages = {425-432},
publisher = {Springer-Verlag},
editor = {U. Visser and F. Ribeiro and T. Ohashi and F. Dellaert},
series = {Lecture Notes in Computer Science/Artificial Intelligence},
address = {Berlin/Heidelberg},
booktitle = {RoboCup 2007: Robot Soccer World Cup XI},
doi = {http://www.springerlink.com/content/41251kv140217484/},
url = {http://www.springer.com/computer/artificial/book/978-3-540-68846-4},
abstract = {Developing and testing the key modules of autonomous humanoid soccer robots (e.g., for vision, localization, and behavior control) in software-in-the-loop (SIL) experiments, requires real-time simulation of the main motion and sensing properties. These include humanoid robot kinematics and dynamics, the interaction with the environment, and sensor simulation, especially the camera properties. To deal with an increasing number of humanoid robots per team the simulation algorithms must be very efficient. In this paper, the simulator framework MuRoSimF (Multi-Robot-Simulation-Framework) is presented which allows the flexible and transparent integration of different simulation algorithms with the same robot model. These include several algorithms for simulation of humanoid robot motion kinematics and dynamics (with O(n) runtime complexity), collision handling, and camera simulation including lens distortion. A simulator for teams of humanoid robots based on MuRoSimF is presented. A unique feature of this simulator is the scalability of the level of detail and complexity which can be chosen individually for each simulated robot and tailored to the requirements of a specific SIL test. Performance measurements are given for real-time simulation on a moderate laptop computer of up to six humanoid robots with 21 degrees of freedom, each equipped with an articulated camera.},
}
@INPROCEEDINGS{2008-Kropf-etal-MMULATOR,
author = {Matthias Kropff and Christian Reinl and Kim Listmann and Karen Petersen and Katayon Radkhah and Faisal Karim Shaikh and Arthur Herzog and Armin Strobel and Daniel Jacobi and Oskar von Stryk},
title = {MM-ulator: Towards a Common Evaluation Platform for Mixed Mode Environments},
year = {2008},
publisher = {Springer (ACCEPTED FOR PUBLICATION)},
booktitle = {Proceedings of Int. Conference on Simulation, Modeling, and Programming (SIMPAR)},
abstract = {We investigate the interaction of mobile robots, relying on information provided by heterogeneous sensor nodes, to accomplish a mission. Cooperative, adaptive and responsive monitoring in Mixed-Mode Environments (MMEs) raises the need for multi-disciplinary research initiatives. To date, such research initiatives are limited since each discipline focusses on its domain specific simulation or testbed environment. Existing evaluation environments do not respect the interdependencies occurring in MMEs. As a consequence, holistic validation for development, debugging, and performance analysis requires an evaluation tool incorporating multi-disciplinary demands. In the context of MMEs, we discuss existing solutions and highlight the synergetic benefits of a common evaluation tool. Based on this analysis we present the \emph{MM-ulator}: a novel architecture for an evaluation tool incorporating the necessary diversity for multi-agent hard-/software-in-the-loop simulation in a modular and scalable way.},
}
@ARTICLE{2008:IJHR-Friedmann-etal,
author = {M. Friedmann and J. Kiener and S. Petters and H. Sakamoto and D. Thomas and O. von Stryk},
title = {Versatile, high-quality motions and behavior control of humanoid robots},
journal = {International Journal of Humanoid Robotics},
year = {2008},
pages = {submitted, under review},
}
@ARTICLE{2008:IJRR-Hemkeretal,
author = {T. Hemker and H. Sakamoto and M. Stelzer and O. von Stryk},
title = {Efficient walking speed optimization of a humanoid robot},
journal = {International Journal of Robotics Research},
year = {2008},
pages = {accepted for publication},
abstract = {The development of optimized motions of humanoid robots that guarantee a fast and also stable walking is an important task especially in the context of autonomous soccer playing robots in RoboCup. We present a walking motion optimization approach for the humanoid robot prototype HR18 which is equipped with a low dimensional parameterized walking trajectory generator, joint motor controller and an internal stabilization. The robot is included as hardware-in-the-loop to define a low dimensional black-box optimization problem. In contrast to previously performed walking optimization approaches we apply a sequential surrogate optimization approach using stochastic approximation of the underlying objective function and sequential quadratic programming to search for a fast and stable walking motion. This is done under the conditions that only a small number of physical walking experiments should have to be carried out during the online optimization process. For the identified walking motion for the considered 55 cm tall humanoid robot we measured a forward walking speed of more than 30 cm/sec. With a modified version of the robot even more than 40 cm/sec could be achieved in permanent operation.},
}
@ARTICLE{2008:IJRR-Seyfarthetal,
author = {A. Seyfarth and R. Tausch and M. Stelzer and F. Iida and A. Karguth and O. von Stryk},
title = {Towards bipedal jogging as a natural result for optimizing walking speed for passively compliant three-segmented legs},
journal = {International Journal of Robotics Research},
year = {2008},
pages = {accepted for publication; see also the video},
abstract = {Elasticity in conventionally built walking robots is an undesired side effect that is suppressed as much as possible because it makes control very hard and thus complex control algorithms must be used. The human motion apparatus, in contrast, shows a very high degree of flexibility with sufficient stability. In this research we investigate how compliance and damping can deliberately be used in humanoid robots to improve walking capabilities. A modular robot system consisting of rigid segments, joint modules and adjustable compliant cables spanning one or more joints is used to configure a human-like biped. In parallel, a complex simulation model of the robot has been established. Walking motion is gained by oscillatory out-of-phase excitations of the hip joints. An optimization of the walking speed has been performed by improving the viscoelastic properties of the leg and identifying the appropriate hip control parameters. A good match was found between real robot experiments and numerical simulations. At higher speeds, transitions from walking to running are found in both the simulation as well as in the robot.},
}
@INPROCEEDINGS{2008:RCS-BeckerRisler,
author = {D. Becker and M. Risler},
title = {Mutual localization in a team of autonomous robots using acoustic robot detection},
year = {2008},
month = {July 15-18},
address = {Suzhou, China},
booktitle = {RoboCup International Symposium},
abstract = {In order to improve self-localization accuracy we are exploring ways of mutual localization in a team of autonomous robots. Detecting team mates visually usually leads to inaccurate bearings and only rough distance estimates. Also, visually identifying teammates is not possible. Therefore we are investigating methods of gaining relative position information acoustically in a team of robots. The technique introduced in this paper is a variant of code-multiplexed communication (CDMA, code division multiple access). In a CDMA system, several receivers and senders can communicate at the same time, using the same carrier frequency. Well-known examples of CDMA systems include wireless computer networks and the Global Positioning System, GPS. While these systems use electro-magnetic waves, we will try to adopt the CDMA principle towards using acoustic pattern recognition, enabling robots to calculate distances and bearings to each other. First, we explain the general idea of cross-correlation functions and appropriate signal pattern generation. We will further explain the importance of synchronized clocks and discuss the problems arising from clock drifts. Finally, we describe an implementation using the Aibo ERS-7 as platform and briefly state basic results, including measurement accuracy and a runtime estimate. We will briefly discuss acoustic localization in the specific scenario of a RoboCup soccer game.},
}
@INPROCEEDINGS{2008:ReinlRuhStolzenburgStryk,
author = {C. Reinl and F. Ruh and F. Stolzenburg and O. von Stryk},
title = {Multi-Robot Systems Optimization and Analysis Using MILP and CLP },
year = {2008},
month = {May 12-16},
address = {Estoril, Portugal},
booktitle = {AAMAS08-Workshop on Formal Models and Methods for Multi-Robot Systems},
abstract = {Formal methods for multi-robot system analysis, specially logic-based methods, operate on discrete models. Optimization methods for simultaneous trajectory and task allocation, namely mixed integer dynamic optimization, operate on hybrid dynamical models which take into account a model of the motion dynamics of the physical robot. In this paper, ongoing work towards a coherent treatment of both approaches is described. A benchmark problem from robot soccer is introduced and used as an illustrative example.},
}
@INPROCEEDINGS{2008:RislervonStryk,
author = {M. Risler and O. von Stryk},
title = {Formal behavior specification of multi-robot systems using hierarchical state machines in XABSL},
year = {2008},
month = {May 12-16},
address = {Estoril, Portugal},
booktitle = {AAMAS08-Workshop on Formal Models and Methods for Multi-Robot Systems},
abstract = {This paper presents the latest developments of the Extensible Agent Behavior Speci cation Language (XABSL), a modular and scalable tool for engineering complex multiagent behavior. It is based on hierarchical finite state machines. By the new extensions the development of cooperative multi agent behavior is supported through language elements which allow to conveniently specify how the state machines of multiple agents interact. Basic properties of XABSL are illustrated in direct comparison with Petri Net Plans and the COLBERT language using examples of basic robot behavior. More complex examples from robot soccer are used to illustrate the new extensions of XABSL. The complete system is available online on the XABSL website (http://www.xabsl.de).},
}
@TECHREPORT{2008:RoboCup-TDP-GermanTeam,
author = {David Becker and Jörg Brose and Daniel Göhring and Matthias Jüngel and Max Risler and Thomas Röfer},
title = {GermanTeam 2008 - The German National RoboCup Team},
year = {2008},
institution = {DFKI Bremen, TU Darmstadt, HU Berlin},
}
@INPROCEEDINGS{2008:Robotik2008-Klugetal,
author = {Sebastian Klug and Thomas Lens and Oskar von Stryk and Bernhard Möhl and Andreas Karguth},
title = {Biologically Inspired Robot Manipulator for New Applications in Automation Engineering},
year = {2008},
number = {2012},
month = {June 11-12},
publisher = {VDI Wissensforum GmbH},
series = {VDI-Berichte},
address = {Munich, Germany},
booktitle = {Proceedings of Robotik 2008},
owner = {FG SIM, TUD},
abstract = {The fast growing interest in flexible, versatile and mobile robotic manipulators demands for robots with inherent high passive safety suited for direct human-robot interaction. To gain access to these new applications in the field of automation engineering where close vicinity and direct cooperating with humans are required, the ""BioRob"" project demonstrates the applicability of a new biologically inspired, lightweight and elastic ""bionic"" robot manipulator specifically designed for safe human-robot interaction. This paper presents the mechanical design and controller structure used for the new demonstrators with up to four compliant joints. The advantages of the design and potential application areas for the manipulator are discussed.},
}
@INCOLLECTION{2008:StelzervonStryk,
author = {M. Stelzer and O. von Stryk},
title = {Walking, running and kicking of humanoid robots and humans},
year = {2008},
pages = {175-192 and 337},
publisher = {Springer Verlag},
editor = {M.H. Breitner and G. Denk and P. Rentrop},
booktitle = {From Nano to Space - Applied Mathematics Inspired by Roland Bulirsch},
abstract = {In this paper key aspects and several methods for modeling, simulation, optimization and control of the locomotion of humanoid robots and humans are discussed. Similarities and differences between walking and running of humanoid robots and humans are outlined. The presented methods are different steps towards the ultimate goals of understanding and predicting human motion by validated simulation models and of developing humanoid robots with human like performance in walking and running. Numerical and experimental results are presented for model-based optimal control as well as for hardware-in-the-loop optimization of humanoid robot walking and for forward dynamics simulation and optimization of a human kicking motion.},
}
@INPROCEEDINGS{cirpicme:2008,
author = {E. Abele and J. Bauer and C. Bertsch and R. Laurischkat and H. Meier and S. Reese and M. Stelzer and O. von Stryk},
title = {Comparison of Implementations of a Flexible Joint Multibody Dynamic System Model for an Industrial Robot},
year = {2008},
pages = {to appear},
booktitle = {6th CIRP International Conference on Intelligent Computation in Manufacturing Engineering},
}
@INPROCEEDINGS{pmi:2008,
author = {E. Abele and J. Bauer and S. Rothenbücher and M. Stelzer and O. von Stryk},
title = {Prediction of the Tool Displacement by Coupled Models of the Compliant Industrial Robot and the Milling Process},
year = {2008},
pages = {to appear},
booktitle = {International Conference on Process Machine Interactions, Hannover, Germany},
}
@INPROCEEDINGS{robotik2008_ptw_sim,
author = {M. Stelzer and O. von Stryk and E. Abele and J. Bauer and M. Weigold},
title = {High speed cutting with industrial robots: Towards model based compensation of deviations},
year = {2008},
booktitle = {Proceedings of Robotik 2008, Munich, Germany},
}
@ARTICLE{wtonline2008,
author = {E. Abele and J. Bauer and M. Stelzer and O. von Stryk},
title = {Wechselwirkungen von Fräsprozess und Maschinenstruktur am Beispiel des Industrieroboters},
journal = {WT online},
year = {2008},
pages = {submitted},
}
@INPROCEEDINGS{2007:AIM-Kratzetal,
author = {R. Kratz and M. Stelzer and M. Friedmann and O. von Stryk},
title = {Control approach for a novel high power-to-weight ratio SMA muscle scalable in force and length},
year = {2007},
pages = {to appear},
month = {September 4-7},
address = {Zürich, CH},
booktitle = {IEEE/ASME Intl. Conf. on Advanced Intelligent Mechatronics (AIM)},
abstract = {The development of a control approach for a novel, soundless, lightweight and multifunctional shape memory alloy (SMA) actuator scalable in force and length for personal assistance or home-help robots is presented in this paper. The SMA actuator is based on lightweight bundles of thin wires of prestrained shape memory alloy that change their length when heated above their transformation temperature. The design approach of the actuator allows arranging the point of actuation in any direction and ensures a short cool down time to guarantee a frequency of contraction/stress cycles that is high enough to allow fast joint motions. This is needed for the generation of fast joint motions. For the use of the actuator the novel control approach has been experimentally validated. The approach uses the resistance of the actuator as a linear position encoder and there are no additional external sensors needed. The application of the new actuator to a novel lightweight humanoid robot is outlined. One advantage of the actuator over electric motors lies in the large variety of user-defined points of actuation of the in pull-force and length free scalable actuators and the high power-to-weight ratio. The results demonstrate that it is possible to build a large humanoid robot actuated with SMA actuator in a new way.},
}
@INPROCEEDINGS{2007:AMS-Friedmannetal,
author = {M. Friedmann and S. Petters and M. Risler and H. Sakamoto and D. Thomas and O. von Stryk},
title = {A new, open and modular platform for research in autonomous four-legged robots},
year = {2007},
pages = {254 - 260},
month = {18 - 19 Oct.},
publisher = {Springer Verlag},
editor = {K. Berns and T. Luksch},
series = {Informatik aktuell},
address = {Kaiserslautern},
booktitle = {Autonome Mobile Systeme 2007},
abstract = {In this paper the design goals for a new, open and modular, four-legged robot platform are described that was developed in reaction to the open call for a standard platform issued by the RoboCup Federation in 2006. The new robot should have similar motion and sensing capabilities like the previously used Sony AIBO plus several new ones. The hardware and software should be open, modular and reconfigurable. The robot should be resonably priced and allow annually upgrades.},
}
@INPROCEEDINGS{2007:Compumag-Hemkeretal,
author = {T. Hemker and O. von Stryk and H. De Gersem and T. Weiland},
title = {Simulation-based design improvement of a superconductive magnet by mixed-integer nonlinear surrogate optimization},
year = {2007},
pages = {449-450},
month = {June 24-28},
address = {Aachen, Germany},
booktitle = {16th Intl. Conf. on the Computation of Electromagnetic Fields - Compumag 2007},
}
@INPROCEEDINGS{2007:FriedmannPetersenVonStryk_WsHumSoc,
author = {M. Friedmann and K. Petersen and O. v. Stryk},
title = {Adequate Motion Simulation and Collision Detection for Soccer Playing Humanoid Robots},
year = {2007},
month = {Nov. 29 - Dec. 1},
address = {Pittsburgh, PA, USA},
booktitle = {Proc. 2nd Workshop on Humanoid Soccer Robots at the 2007 IEEE-RAS Int. Conf. on Humanoid Robots},
url = {http://www.humanoidsoccer.org/ws07/program.html},
abstract = {In this paper a humanoid robot simulator built with the Multi-Robot-Simulation-Framework (MuRoSimF) is presented. Among the unique features of the this simulator is the scalability in the level of physical detail in both the robot’s motion and sensing systems. It facilitates the development of control software for humanoid robots which is demonstrated for several scenarios from the RoboCup Humanoid Robot League. Different requirements exist for a humanoid robot simulator. E.g., testing of algorithms for motion control and postural stability require high fidelity of physical motion properties where as testing of behavior control and role distribution for a robot team requires only a moderate level of detail for real-time simulation of multiple robots. To meet such very different requirements often different simulators are used which makes it neccessary to model a robot multiple times and to integrate different simulations with high-level robot control software. MuRoSimF provides the capability of exchanging the simulation algorithms used for each robot transparently, thus allowing a trade-off between computational performance and fidelity of the simulation. It is therefore possible to choose different simulation algorithms which are adequate for the needs of a given simulation experiment, for example, motion simulation of humanoid robots based on kinematical, simplified dynamics or full multibody system dynamics algorithms. In this paper the sensor simulation capabilities of MuRoSimF are revised and the algorithms for motion simulation and collision detection and handling are presented in detail. An algorithm is presented which allows the real time simulation of the full dynamics of a 21 DOF humanoid robot. Special consideration is given to the merits and drawbacks of the different algorithms depending on the scenario. The simulation’s performance is measured and comparisons with the experimental performance of the humanoid robots are given.},
}
@INPROCEEDINGS{2007:IROS-Kiener-vonStryk,
author = {J. Kiener and O. von Stryk},
title = {Cooperation of heterogeneous, autonomous robots: A case study of humanoid and wheeled robots},
year = {2007},
pages = {959-964},
month = {Oct. 29 - Nov. 2},
address = {San Diego, CA, USA},
booktitle = {Proc. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)},
abstract = {In this paper we present a case study of cooperation of a strongly heterogeneous robot team, composed of a highly articulated humanoid robot and a wheeled robot with largely complementing and some competing capabilities. By combining two strongly heterogeneous robots the diversity of accomplishable tasks increases as the variety of sensors and actuators in the robot systems is extended compared with a team consisting of homogeneous robots. The scenario describes a tightly cooperative task, where the humanoid robot and the wheeled robot follow for a long distance a ball, which is kicked finally by the humanoid robot into a goal. The task can be fulfilled successfully by combining the abilities of both robots. For task distribution and allocation, a newly developed objective function is presented which is based on a proper modeling of the sensing, perception, motion and onboard computing capabilities of the cooperating robots. Aspects of reliability and fault tolerance are considered.},
}
@INPROCEEDINGS{2007:IROS-WS-Architectures-PettersThomasvonStryk,
author = {S. Petters and D. Thomas and O. von Stryk},
title = {RoboFrame - A Modular Software Framework for Lightweight Autonomous Robots},
year = {2007},
month = {Oct. 29},
address = {San Diego, CA, USA},
booktitle = {Proc. Workshop on Measures and Procedures for the Evaluation of Robot Architectures and Middleware of the 2007 IEEE/RSJ Int. Conf. on Intelligent Robots and Systems},
url = {http://wiki.robot-standards.org/index.php/IROS_2007_WS},
abstract = {The complexity of autonomous robot systems has increased dramatically in recent years. Besides an increased variety of robots, sensors, actuators, onboard computers and intelligent algorithms, the architecture of the software has gained crucial relevance with respect to the efficiency for adopting a robotic system to new hardware, new software or new tasks. For evaluation of different robot architectures and middleware not only a set of set of evaluation criterias is required. At least equally important for an evaluation is to define a representative set of the boundary conditions, i.e., different types of robots, tasks and scenarios as well as robot programmers. How the different criteria of an evaluation will be weighted also depends on these boundary conditions. To address the special needs of heterogeneous teams of autonomous lightweight robots, the software framework RoboFrame has been developed. Its main characteristics are platform independency, modularity and high efficiency. It is also bundled with a library of common components for robot control software, which provides much more support to the robot programmer than a robot middleware system alone. },
}
@INPROCEEDINGS{2007:RCS-JuengelRisler,
author = {Matthias Jüngel and Max Risler},
title = {Self-Localization Using Odometry and Horizontal Bearings to Landmarks},
year = {2007},
note = {to appear},
publisher = {Springer},
editor = {U. Visser and F. Ribeiro and T. Ohashi and F. Dellaert},
series = {Lecture Notes in Artificial Intelligence},
booktitle = {RoboCup 2007: Robot Soccer World Cup XI},
}
@INPROCEEDINGS{2007:ReinlVonStryk_ROBOCOMM,
author = {Christian Reinl and Oskar von Stryk},
title = {Optimal Control of Multi-Vehicle Systems Under Communication Constraints Using Mixed-Integer Linear Programming},
year = {2007},
month = {Oct. 15-17},
address = {Athens, Greece},
booktitle = {Proceedings of the. First International Conference on Robot Communication and Coordination (RoboComm)},
organization = {ICST},
keywords = {connectivity network, mobile communication network, linearized optimal control, mixed-integer linear optimal control, cooperative multi-vehicle system},
abstract = {A new planning method for optimal cooperative control of heterogeneous multi-vehicle systems is investigated which enables to account for each vehicle’s nonlinear physical motion dynamics in a structured environment as well as for connectivity constraints of wireless communication. A general formulation as nonlinear hybrid optimal control problem (HOCP) is presented. A transformation technique is proposed to reduce the large computational efforts for solving HOCPs towards a future online application of this approach. Hereby the general problem is transcribed to a linearized mixed-integer linear programming problem (MILP) which can be solved much more efficiently. The proposed approach is successfully applied to the numerical solution of a representative, cooperative monitoring problem involving heterogeneous vehicles and conditions.},
}
@INPROCEEDINGS{2007:ReinlVonStryk_RoboMat,
author = {C. Reinl and O. von Stryk},
title = {Optimal Control of Cooperative Multi-Robot Systems Using Mixed-Integer Linear Programming},
year = {2007},
pages = {145 - 151},
month = {Sept. 17-19},
editor = {Centro Internacional de Mathematica},
address = {Coimbra, Portugal},
booktitle = {Proc. RoboMat 2007},
url = {http://labvis.isr.uc.pt/robomat/},
abstract = {A new planning method for optimal control of multi-robot systems is discussed which accounts for the (continuous) physical locomotion dynamics of the robots and its tight coupling to the distribution and allocation of (discrete) subtasks to the robots to fulfill a joint mission. The point of departure is a nonlinear and nonconvex hybrid optimal control problem (HOCP) formulation which incorporates a detailed hybrid automaton model. Because of the many difficulties involved in solving this problem like large computational times and the lack of good or global convergence properties it is transcribed into a mixed- integer linear program (MILP). This can be solved much more efficiently using existing algorithms. The proposed approach is outlined for an example problem of cooperative soccer robots. The MILP solution itself may serve either as a good initial solution estimate for a method addressing the nonlinear HOCP or may later become the kernel of a model predictive control method for cooperative multi-robot systems. Despite the promising results obtained so far a variety of open questions yet remains to be answered including the ”best” way of transcribing HOCP to MILP with respect to both computational efficiency and good HOCP solution approximation. },
}
@TECHREPORT{2007:RoboCup-TDP-Dribblers,
author = {M. Friedmann and J. Kiener and S. Petters and D. Thomas and O. von Stryk},
title = {Darmstadt Dribblers: Team Description for Humanoid KidSize League of RoboCup 2007},
year = {2007},
note = {11 pages},
institution = {Technisch Universität Darmstadt},
abstract = {This paper describes the hardware and software design of the kidsize humanoid robot systems of the Darmstadt Dribblers in 2007. The robots are used as a vehicle for research in control of locomotion and behavior of autonomous humanoid robots and robot teams with many degrees of freedom and many actuated joints. The Humanoid League of RoboCup provides an ideal testbed for such aspects of dynamics in motion and autonomous behavior as the problem of generating and maintaining statically or dynamically stable bipedal locomotion is predominant for all types of vision guided motions during a soccer game. A modular software architecture as well as further technologies have been developed for efficient and effective implementation and test of modules for sensing, planning, behavior, and actions of humanoid robots.},
}
@TECHREPORT{2007:RoboCup-TDP-GermanTeam,
author = {T. Röfer and J. Brose and D. Göhring and M. Jüngel and T. Laue and M. Risler},
title = {GermanTeam 2007 - The German National RoboCup Team},
year = {2007},
institution = {DFKI Bremen, TU Darmstadt, HU Berlin, Universität Bremen},
}
@INPROCEEDINGS{biomed:2006,
author = {M. Stelzer and O. von Stryk},
title = {Human Kicking Motion Using Efficient Forward Dynamics Simulation and Optimization},
year = {2007},
volume = {15},
pages = {192--196},
publisher = {Springer, Berlin},
editor = {F. Ibrahim and N. A. Abu Osman and J. Usman and N. A. Kadri},
booktitle = {3rd Kuala Lumpur International Conference on Biomedical Engineering 2006: Biomed 2006, 11-14 December 2006, Kuala Lumpur, Malaysia},
doi = {10.1007/978-3-540-68017-8},
}
@ARTICLE{hemker_et_al_2008,
author = {T. Hemker and H. De Gersem and O. von Stryk and T. Weiland},
title = {Mixed-Integer Nonlinear Design Optimization of a Superconductive Magnet},
journal = {IEEE Transactions on Magnetics},
year = {2007},
volume = {44},
number = {6},
pages = {1110-1113},
month = {June},
abstract = {The numerical optimization of continuous parameters in electrotechnical design using electromagnetic field simulation is already standard. When integer-valued variables are involved, the complexity of the optimization problem rises drastically. In this paper, we describe a new sequential surrogate optimization approach for simulation-based mixed-integer nonlinear programming problems. We apply the method for the optimization of combined integer- and real-valued geometrical parameters of the coils of a superconductive magnet.},
}
@INPROCEEDINGS{2006:ACTUATORKratzStelzervonStryk,
author = {R. Kratz and M. Stelzer and O. von Stryk},
title = {Design, measurement experiments and application of a macroscopic shape memory alloy actuator system},
year = {2006},
month = {June 14-15},
address = {Bremen, Germany},
booktitle = {ACTUATOR 2006 - 10th International Conference on New Actuators},
abstract = {Prestrainend shape memory alloys (SMA) change their length when heated above their transformation temperature. Based on this property various micro-technical actuators have been developed in the past. This paper presents the design of novel macroscopic SMA actuators scalable in force and length. Our design approach allows arranging the point of actuation in any direction and ensures a short cool down time to guarantee a high frequency of contraction/stress cycles. The use of the new actuator also necessitates a novel control approach. A model to describe the actuators behavior has been developed and experimentally validated. It offers the possibility of using the resistance of the actuator as a linear position encoder and provides a basis for the control approach of the actuator. The application to a new bipedal walking robot demonstrates one envisioned future use of the actuators. One advantage over electric motors lies in the large variety of user-defined points of actuation of the scalable actuators on a mechanical structure. This allows generating joint movements without the common restrictions holding for electric motors on the possible point of actuation. },
}
@INCOLLECTION{2006:BionikGothavonStryk,
author = {O. von Stryk},
title = {Ihr intelligenter "Personal Robot" im Jahr 2050: Haushaltshilfe, Terminator oder Fußballspieler?},
year = {2006},
pages = {48-50},
publisher = {Stiftung Schloss Friedenstein Gotha},
editor = {Museum der Natur Gotha},
address = {Gotha, Germany},
booktitle = {Bionik - Vom Ursaurier zum laufenden Roboter},
}
@INPROCEEDINGS{2006:CLAWARHemkeretal,
author = {Th. Hemker and H. Sakamoto and M. Stelzer and O. von Stryk},
title = {Hardware-in-the-loop optimization of the walking speed of a humanoid robot},
year = {2006},
pages = {614-623},
month = {September 11-14},
address = {Brussels, Belgium},
booktitle = {CLAWAR 2006: 9th International Conference on Climbing and Walking Robots},
abstract = {The development of optimized motions of humanoid robots that guarantee a fast and also stable walking is an important task especially in the context of autonomous soccer playing robots in RoboCup. We present a walking motion optimization approach for the humanoid robot prototype HR18 which is equipped with a low dimensional parameterized walking trajectory generator, joint motor controller and an internal stabilization. The robot is included as hardware-in-the-loop to define a low dimensional black-box optimization problem. In contrast to previously performed walking optimization approaches we apply a sequential surrogate optimization approach using stochastic approximation of the underlying objective function and sequential quadratic programming to search for a fast and stable walking motion. This is done under the conditions that only a small number of physical walking experiments should have to be carried out during the online optimization process. For the identified walking motion for the considered $55$ cm tall humanoid robot we measured a forward walking speed of more than $30$ cm/sec. With a modified version of the robot even more than $40$ cm/sec could be achieved in permanent operation.},
}
@INPROCEEDINGS{2006:CLAWARSeyfarthetal,
author = {A. Seyfarth and R. Tausch and M. Stelzer and F. Iida and A. Karguth and O. von Stryk},
title = {Towards bipedal running as a natural result of optimizing walking speed for passively compliant three-segmented legs},
year = {2006},
pages = {396-401},
month = {September 12-14},
address = {Brussels, Belgium},
booktitle = {CLAWAR 2006: 9th International Conference on Climbing and Walking Robots},
abstract = {Elasticity in conventionally built walking robots is an undesired side-effect that is oppressed as much as possible because it makes control very hard, and thus complex control algorithms must be used. The human motion apparatus, in contrast, shows a very high degree of flexibility with suffcient stability. In this research we investigate how elasticities and damping can sensibly be used in humanoid robots to improve walking capabilities. A modular robot system consisting of rigid segments, joint modules and adjustable elastic strings spanning one or more joints is used to configure a human-like biped. In parallel, a complex simulation model of the robot has been established. Walking motion is gained by oscillatory out-of-phase excitations of the hip joints. An optimization of the walking speed has been performed by improving the viscoelastic properties of the leg and identifying the appropriate hip control parameters. Experiments on the real robot very well matched the numerical results. At higher speeds, transitions from walking to running are found in both the simulation as well as in the robot.},
}
@INPROCEEDINGS{2006:HumanoidsSoccerWS-DarmstadtDribblersandHajimeTeam,
author = {M. Friedmann and J. Kiener and S. Petters and H. Sakamoto and D. Thomas and O. von Stryk},
title = {Versatile, high-quality motions and behavior control of humanoid soccer robots},
year = {2006},
pages = {9-16},
month = {Dec. 4-6},
address = {Genoa, Italy},
booktitle = {Proc. Workshop on Humanoid Soccer Robots of the 2006 IEEE-RAS Int. Conf. on Humanoid Robots},
url = {http://www.dei.unipd.it/~emg/whs2006/schedule.html},
abstract = {Many different and high-quality humanoid otions have been developed based on a tailored, 55cm tall humanoid robot kinematics and design using 21 servo motors and inertial sensors for stabilization. These include fast forward walking of about 1.5 km/h in permanent operation, multidirectional walking capabilities, a variety of standard and spectacular kicks, standing up motions as well as motions displaying an emotional state of the robot. While all robot motions are executed in real-time on a controller board an adaptive selection of different motions and autonomous robot behavior are controlled by hierarchical state machine executed on an onboard Pocket PC. Information about the current state of the dynamic environment in a soccer game is obtained from two directed cameras with wide and narrow angles. During RoboCup 2006 the robot demonstrated the fastest walking of all kid- and teen-size humanoid robots on regular terrain as well as in the rough terrain challenge. Also a large variety of different motions as well as individual and team behaviors during successful autonomous soccer games have been demonstrated including the scoring of a goal with the first autonomously performed backheel kick of a humanoid robot.},
}
@INPROCEEDINGS{2006:IFAC-MVS-Friedmann-etal,
author = {M. Friedmann and J. Kiener and S. Petters and D. Thomas and O. von Stryk },
title = {Reusable architecture and tools for teams of lightweight heterogeneous robots},
year = {2006},
pages = {51-56},
month = {October 2-3},
address = {Salvador, Brazil},
booktitle = {Proc. 1st IFAC Workshop on Multivehicle Systems},
abstract = {The software framework RoboFrame has been designed to meet the special requirements for teams of lightweight autonomous heterogeneous robot systems. Due to platform abstraction and modern object oriented design, it allows the reuse of components of common robot control software. It can also efficiently be implemented on new platforms and enables different control architectures for different tasks. For the exemplary application in autonomous robot soccer teams configurable and portable algorithms for vision, world modeling, behavior and motion control have been developed on top of the framework. For debugging, controlling and monitoring, an extendable graphical user interface and a generic simulator package have been implemented around the framework. Based on these instruments, different applications for homogeneous and heterogeneous robot teams can be realized in short time.},
}
@INPROCEEDINGS{2006:IFAC-MVS-GlockerReinlvonStryk,
author = {M.Glocker and C. Reinl and O. von Stryk},
title = {Optimal task allocation and dynamic trajectory planning for multi-vehicle systems using nonlinear hybrid optimal control},
year = {2006},
pages = {38-43},
month = {October 2-3},
address = {Salvador, Brazil},
booktitle = {Proc. 1st IFAC-Symposium on Multivehicle Systems},
abstract = {Based on a nonlinear hybrid dynamical systems model a new planning method for optimal coordination and control of multiple unmanned vehicles is investigated. The time dependent hybrid state of the overall system consists of discrete (roles, actions) and continuous (e.g. position, orientation, velocity) state variables of the vehicles involved. The evolution in time of the system’s hybrid state is described by a hybrid state automaton. The presented approach enables a tight and formal coupling of discrete and continuous state dynamics, i.e. of dynamic role and action assignment and sequencing as well as of the physical motion dynamics of a single vehicle modeled by nonlinear differential equations. The planning problem of determining optimal hybrid state trajectories that minimize a cost function as time or energy for optimal multi-vehicle cooperation subject to constraints including the vehicle’s motion dynamics is transformed to a mixed-binary dynamic optimization problem being solved numerically. The numerical method consists of an inner iteration where multiphase optimal control problems are solved using a direct collocation method and an outer iteration based on a branch-and-bound search of the discrete solution space. The approach presented in this paper is applied to the scenarios of optimal simultaneous waypoint or target sequencing and dynamic trajectory planning for a team of unmanned aerial vehicles in a plane and to optimal role assignment and physics-based trajectories in robot soccer.},
}
@INPROCEEDINGS{2006:IFACKratzStelzervStryk,
author = {R. Kratz and M. Stelzer and O. von Stryk},
title = {Macroscopic SMA wire bundle actuator/sensor system: design, measurement, control approach},
year = {2006},
month = {September 12-14},
address = {Heidelberg},
booktitle = {Proc. 4th IFAC-Symposium on Mechatronic Systems},
}
@INPROCEEDINGS{2006:IROSLoetzschRislerJuengel,
author = {M. Lötzsch and M. Risler and M. Jüngel},
title = {XABSL - A Pragmatic Approach to Behavior Engineering},
year = {2006},
pages = {5124-5129},
month = {October 9-15},
address = {Beijing, China},
booktitle = {Proceedings of IEEE/RSJ International Conference of Intelligent Robots and Systems (IROS)},
abstract = {This paper introduces the Extensible Agent Behavior Specification Language (XABSL) as a pragmatic tool for engineering the behavior of autonomous agents in complex and dynamic environments. It is based on hierarchies of finite state machines (FSM) for action selection and supports the design of longterm and deliberative decision processes as well as of short-term and reactive behaviors. A platform-independent execution engine makes the language applicable on any robotic platform and together with a variety of visualization, editing and debugging tools, XABSL is a convenient and powerful system for the development of complex behaviors. The complete source code can be freely downloaded from the XABSL website (http://www.informatik.huberlin.de/ki/XABSL/). The language has been successfully applied on many robotic platforms, mainly in the domain of RoboCup robot soccer. It gave the GermanTeam the crucial advantage over other teams to become the 2004 and 2005 world champion in the Four-Legged League and helped the team CoPS Stuttgart to become third in the Middle Size League in 2004.},
}
@INCOLLECTION{2006:MoehlvonStryk-Bionikbuch,
author = {Bernhard Möhl and Oskar von Stryk},
title = {Menschen aus Stahl},
year = {2006},
pages = {174-180},
publisher = {Bionik Media},
editor = {K.G. Blüchel and F. Malik},
booktitle = {Faszination Bionik - Die Intelligenz der Schöpfung},
}
@INPROCEEDINGS{2006:ROBIO-Friedmannetal,
author = {M. Friedmann and J. Kiener and S. Petters and D. Thomas and O. von Stryk},
title = {Modular software architecture for teams of cooperating, heterogeneous robots},
year = {2006},
pages = {613-618},
month = {December 17-20},
address = {Kunming, China},
booktitle = {Proc. IEEE International Conference on Robotics and Biomimetics (ROBIO)},
abstract = {For teams of cooperating autonomous lightweight robots with challenging dynamical locomotion properties a platform independent modular software architecture and platform independent modules for sensor data processing, planning and motion control have been developed. The software architecture allows high level communication between modules on different abstraction levels of the control architecture within one robot system as well as communication between different and heterogeneous robots and computers using wireless network. Very different behavior control paradigms may be realized on the basis of the developed architecture. The application to teams of cooperating small and medium size humanoid robots is investigated in this paper. Scenarios for inter robot communication and cooperative task accomplishment are described.},
}
@INPROCEEDINGS{2006:ROBIO-Kratzetal,
author = {R. Kratz and S. Klug and M. Stelzer and O. von Stryk},
title = {Biologically inspired reflex based stabilization control of a humanoid robot with artificial {SMA} muscles},
year = {2006},
pages = {1089-1094},
month = {December 17-20},
address = {Kunming, China},
booktitle = {Proc. IEEE International Conference on Robotics and Biomimetics (ROBIO)},
abstract = {Suddenly occurring collisions or unintentional motions represent a high safety risk in robotics and must be prevented. Especially for humanoid robots, the influence of disturbances that occur unexpectedly during bipedal locomotion are difficult to compensate. A model based online control approach for stabilization of a humanoid robot with many degrees of freedom may require too much time for computing and implementing an adequate compensating motion. In addition, such a control approach usually requires accurate sensor information about the type and magnitude of the disturbance. The goal of the present paper is a reflex based online stabilization control of a humanoid robot actuator based on artificial SMA muscles. The design of a humanoid robot actuated with SMA muscles allows a lightweight robot design and simplifies the direct implementation of reflexes. The reflex that is integrated into the robot depends on an evaluation of the pressure distribution of the feet. An instable position of the center of mass of the robot leads to a known specific pressure disturbance that should be avoided. The experiments show that the implementation of a reflex for the actuators in the calf leads to a stabilization of the entire robot. Additional reflexes are required when the strength or speed of disturbances are increased, such as in the upper leg or arms.},
}
@ARTICLE{2006:ZAMM_Stelzer_vonStryk,
author = {Maximilian Stelzer and Oskar von Stryk},
title = {Efficient Forward Dynamics Simulation and Optimization of Human Body Dynamics},
journal = {ZAMM, Zeitschrift für Angewandte Mathematik und Mechanik, Journal of Applied Mathematics and Mechanics},
year = {2006},
volume = {86},
number = {10},
pages = {828-840},
keywords = {Forward dynamics simulation, forward dynamics optimization, multibody systems, optimal control, biomechanics, human motion},
}
@INPROCEEDINGS{2006BioRob:KlugvonStrykMoehl,
author = {S. Klug and O. von Stryk and B. Möhl},
title = {Design and Control Mechanisms for a 3 DOF Bionic Manipulator},
year = {2006},
number = {210},
month = {February 20-22},
address = {Pisa, Italy},
booktitle = {Proc. 1st IEEE / RAS-EMBS Intl. Conf. on Biomedical Robotics and Biomechatronics (BioRob)},
url = {http://www.biorob.de},
abstract = {Functionality and design of a bionic robot arm consisting of three joints driven by elastic and compliant actuators derived from biologically inspired principles are presented. In the first design standard springs with linear characteristics are utilized in combination with electrical drives. Different control approaches for the bionic robot arm are presented, discussed and evaluation in numerical simulations and experiments with regards to the long-term goal of a natural-like control perfomance.},
}
@INPROCEEDINGS{2006_hemker_CEM,
author = {Th. Hemker and M. Glocker and H. De Gersem and O. von Stryk and Th. Weiland},
title = {Mixed-integer simulation-based optimization for a superconductive magnet design},
year = {2006},
month = {4-6 April},
booktitle = {Proc. of the Sixth International Conference on Computation in Electromagnetics},
organization = {VDE},
abstract = {The optimization of continuous parameters in electrotechnical designs using electromagnetic field simulation is already standard. Typically, the simulation tools only carry out evaluations of the objective function and do not provide gradient information. If in addition to continuous design parameters also integer design parameters have to be optimized, only computational expensive random search methods like genetic algorithms are well known. In this paper, we present a new sequential modeling approach to solve mixed-integer simulation-based optimiza-tion problems for an electrotechnical design problem for superconductive magnets. Each step of this approach uses stochastic modeling techniques to predict the simulation output by a surrogate function. The surrogate function treats the integer variables as real-valued ones. New promising parameter con-figurations are predicted by a “branch-and-bound” method, which solves the purely continuous subproblems by classical optimization methods for continuous and differentiable functions. The additional information of these simulation runs improves the quality of the surrogate function step by step. The proposed approach is applied to optimize the distribution of coil blocks and coil windings of a superconduc-tive magnet such that a maximal homogeneity of the magnetic field in the aperture is achieved.},
}
@INPROCEEDINGS{2006_hemker_CMWR,
author = {Th. Hemker and K.R. Fowler and O. von Stryk},
title = {Derivative-Free Optimization Methods for Handling Fixed Costs in Optimal Groundwater Remediation Design},
year = {2006},
month = {19-22 June},
booktitle = {Proc. of the CMWR XVI - Computational Methods in Water Resources},
abstract = {Groundwater remediation design problems are routine in water resource management. The starting point for such a design problem is to formulate an objective function that represents a measure of the manager´s goal. For example, in plume migration control, we need to determine the cost to design a well field to alter the direction of groundwater flow and thereby control the destination of a contaminant. Constraints must be specified to ensure that the plume is captured, the physical domain is protected, and the wells operate under realistic conditions. Optimization algorithms must work in conjunction with groundwater flow and possibly contaminant transport simulators to determine the minimal cost well design subject to the constraints, but typically these numerical simulation codes have been developed for many years and have usually not been designed to meet the specific needs of optimization methods as, e.g., providing gradient information. Decision variables can be real-valued, in the case of pumping rates and well locations, or integer valued in the case of the number of wells in the design. In this work we focus on formulations that include a fixed installation cost as well as an operating cost, resulting in a simulation-based nonlinear mixed-integer optimization problem. The motivation is that our preliminary studies have shown that convergence to an unsatisfactory, local minimum with many wells operating at low pumping rates is common when the fixed cost is ignored. The challenge in the fixed cost formulation is the integer variable for the number of wells in the design. Removing a well from the design space leads to a large decrease in cost meaning optimizers must be equipped to either handle a mixed-integer or approximate mixed integer, black-box problem and discontinuities in the objective function. Moreover since evaluation of the objective function requires numerical results from a simulation, derivative information is unavailable. Gradient based optimization methods are not appropriate for these applications, hence methods that rely only on function values are more appealing. We compare three methods for handling the installation cost on a hydraulic capture benchmarking problem proposed in the literature. All the approaches described below do not use the gradient of the objective function, only function values for minimization. In one approach, we use penalty coefficients proposed in the literature for the installation term to transform the discontinuous problem into a continuous one. In another approach, we bypass including the number of wells as a decision variable by defining an inactive-well threshold. In the course of the optimization, if a well rate falls in this threshold, the well is removed from the design space, leading to large discontinuities in the objective function. For the two above formulations, we use the implicit filtering algorithm, a method which uses a sequence of finite difference gradients, for minimization. In the third approach, we use sequential stochastic modeling to build surrogate functions to approximate the original objective function. With this procedure the use of a branch and bound technique becomes possible to solve the mixed integer problem in contrast to methods working directly on the simulation results, which impedes relaxation of integer variables. We present promising preliminary numerical results on the benchmarking problem and point the way towards improvement and future work. },
}
@INPROCEEDINGS{icmmb:2006,
author = {M. Stelzer and O. von Stryk},
title = {Applications of Efficient Forward Dynamics Simulation in Biomechanics},
year = {2006},
booktitle = {Proceedings of the XVth International Conference on Mechanics in Medicine and Biology, Singapore},
}
@INPROCEEDINGS{MATHMOD2006,
author = {R. Höpler and M. Stelzer and O. von Stryk},
title = {Object-Oriented Dynamics Modeling of Walking Robots for Model-Based Trajectory Optimization and Control},
year = {2006},
number = {30},
editor = {I. Troch and F. Breitenecker},
series = {ARGESIM Reports},
booktitle = {Proc. 5th MATHMOD Vienna, February 8-10},
abstract = {Modeling walking robot dynamics is an intricate subject when dealing with optimization and model based control. When modeled as multibody systems with a free floating base walking robots lead to high dimensional equation systems. Walking involves frequent changes in the kinematic structure due to varying contact situations. However, specialized algorithms that treat the contacts separately and thus can make use of the tree structure of the system can be used. This paper discusses the dynamics algorithms used and discusses the development and application of objectoriented modeling and implementation techniques to achieve a representation of the mechanical model amenable to the various requirements by legged robot applications. Optimal control techniques are involved to generate optimal walking trajectories of a biped and a quadruped robot. Numerical results are shown.},
}
@INPROCEEDINGS{2005:ButzEhmann,
author = {T. Butz and M. Ehmann},
title = {Virtuelle Rundenzeitoptimierung mittels realistischer Rennfahrzeugsimulation},
year = {2005},
month = {13.-14. Oktober 2005},
publisher = {TÜV Süd Gruppe},
address = {Garching},
booktitle = {Proc. race.tech},
abstract = {Der Einsatz von maßeschneiderten Fahrdynamik-Simulationspaketen ist Stand der Technik bei der Entwicklung von Rennfahrzeugen. Neben dem virtuellen Prototypenbau können schnelle Simulationsmodelle zu Konzeptuntersuchungen und zur Optimierung einzelner Fahrzeugkomponenten dienen. Die Entwicklung von Fahrdynamikreglern wird während des gesamten Entwicklungszyklus unterstützt, vom ersten Entwurf des Regelalgorithmus bis hin zu Funktionstests und Abstimmung des Steuergeräts in Echtzeitumgebungen, wo eine Implementierung des Reglers in Software oder Hardware mittels Sensoren und Aktuatoren mit der Vollfahrzeugsimulation verbunden ist. Zur Simulation der Rennfahrzeugdynamik wird neben einem präisen physikalischen Fahrzeugmodell ein Fahrermodell benötigt, das das virtuelle Fahrzeug im fahrdynamischen Grenzbereich präzise langs zeitoptimaler Führungsgrößen für die Ideallinie und das Geschwindigkeitsprofil führen kann. In diesem Beitrag wird eine Strategie zur Rundenzeitoptimierung vorgestellt, in der eine näherungsweise optimale Startlösung für die Sollgeschwindigkeit durch den Einsatz von nichtlinearen Optimierungsverfahren iterativ verbessert wird. Ergebnisse der Optimierung und die Grenzen der Vorgehensweise werden diskutiert.},
}
@INCOLLECTION{2005:GlockerMartinvonStryk,
author = {Markus Glocker and Alexander Martin and Oskar von Stryk},
title = {Optimale kooperative Steuerung von Mehrflugzeugsystemen},
year = {2005},
number = {3/2005},
pages = {14-18},
publisher = {Technische Universität Darmstadt},
editor = {Uwe Klingauf},
series = {thema Forschung},
address = {Darmstadt},
booktitle = {thema Forschung - Im Aufwind: Luftverkehr},
url = {http://www.tu-darmstadt.de/aktuell/thema-forschung/},
abstract = {Die Untersuchung und Optimierung von Koordination und Flugtrajektorien zur Erhöhung von Kapazität und Sicherheit im Luftverkehr unter Berücksichtigung von Freiflugphasen und neuen Möglichkeiten der Flugregelung führt bei realitätsnaher Modellierung der Flugzeugdynamik auf eine gänzlich neue Klasse von diskret-kontinuierlichen dynamischen Optimierungsproblemen. Damit können die simultane Optimierung von Flugtrajektorien und Landereihenfolge bei Flughäfen ebenso beschrieben werden wie die Koordination und Trajektorienoptimierung einer Flotte unbemannter Flugsysteme zur Verkehrsüberwachung oder Aufklärung bei Katastrophen. Erste Ansätze für numerische Berechnungsverfahren werden diskutiert und an Beispielen illustriert.},
}
@INCOLLECTION{2005:SpringerVideoRettig-etal,
author = {U. Rettig and R. Bulirsch and O. von Stryk and R.H.W. Hoppe},
title = {Modeling, simulation and control of electrorheological fluid dampers},
year = {2005},
publisher = {Springer-Verlag},
editor = {H.-J. Bungartz, R.-P. Mundani, A.C. Frank},
series = {Springer VideoMATH},
type = {DVD, Video, PAL},
booktitle = {Bubbles, Jaws, Moose Tests, and More: The Wonderful World of Numerical Simulation},
abstract = {This video introduces the mathematical challenges in modeling, simulation and control of new continuously controllable shock absorbers based on electrorheological fluids (ERF) within automobiles. The basic mode of operation of an ERF is demonstrated by an experiment. Simulations demonstrate the interaction between controllable shock absorbers with a wide range of characteristics, the road and the multibody system of the motor vehicle. Mathematical questions considered during this project concern modeling, parameter estimation, optimal control and dynamic simulation. Parametric models predicting the dynamic behavior of the damper characteristics must be developed but also validated and calibrated by ERF flow simulations and experimental results. New optimal control strategies based on quarter car or half car models enable almost optimal use of the ERF shock absorbers with respect to dring safety and comfort. A well known driving maneuver, performed in three different configurations, demonstrates the innovative potential of optimally controlled ERF shock absorbers. The simulation is based on a full vehicle dynamics model augmented with the new ERF shock absorbers and the new optimal controllers, and it includes complex submodels not only for the vehicle"s multibody system, drive train, axle kinematics and tires but also for the driver and the road.},
}
@INPROCEEDINGS{2005AMAM:KlugMoehlvonStrykBart,
author = {S. Klug and B. Möhl and O. von Stryk and O. Barth},
title = {Design and application of a 3 DOF bionic robot arm},
year = {2005},
month = {September 25-30},
note = {in press},
address = {Ilmenau, Germany},
booktitle = {Proc. 3rd Intl. Symposium on Adaptive Motion in Animals and Machines (AMAM)},
url = {http://www.biorob.de},
abstract = {Regarding to concrete industrial applications, we examined the functionality and the systematic design of a bionic robot arm developed and driven by biologically inspired principles. Based on a laboratory model a scalable multi-bodydynamics-simulation model has bin developed. Although it is driven by elastically coupled linkages which require additional control efforts for oscillation damping, we can show possible advantages of a lighter and bending relieved structure and a significant reduction of danger in case of collisions.},
}
@INPROCEEDINGS{AMAM2005,
author = {M. Stelzer and O. von Stryk},
title = {Efficient forward dynamics simulation and optimization of locomotion: from legged robots to biomechanical systems},
year = {2005},
month = {September 25-30},
booktitle = {Proc. 3rd Intl. Symposium on Adaptive Motion in Animals and Machines (AMAM)},
}
@INPROCEEDINGS{ASIM:2005,
author = {R. Höpler and M. Stelzer and O. von Stryk},
title = {Object-oriented dynamics modeling for simulation, optimization and control of walking robots},
year = {2005},
pages = {588--593},
month = {September 12-15},
booktitle = {Proc. 18th Symposium on Simulation Technique, ASIM, Erlangen},
}
@INPROCEEDINGS{ButzStryk:2005,
author = {T. Butz and O. von Stryk},
title = {Optimal control based modeling of vehicle driver properties},
year = {2005},
number = {SAE Paper 2005-01-0420},
month = {April 11-14},
address = {Detroit, MI},
booktitle = {Society of Automotive Engineers (SAE) 2005 World Congress},
abstract = {In this paper, we present a two-level driver model for the use in real-time vehicle dynamics applications. On the anticipation level of this model, nominal trajectories for the path and the speed profile of the vehicle along a given course are determined by reducing the driving task to a parametric optimal control problem and using an efficient direct collocation method for its solution. Typical optimality criteria and control-state constraints serve to depict driving properties of different driver types. On the stabilization level, a nonlinear position controller guides the full vehicle dynamics model along the prescribed trajectories in real-time. This synthetic driver model allows easy implementation of different driving strategies to simulate a wide range of driver types and vehicles. The expediency of the proposed model is shown by comparing simulation results with measured data from several drivers performing ISO double lane changes with a passenger car.},
}
@TECHREPORT{DD:2005,
author = {M. Friedmann and J. Kiener and R. Kratz and T. Ludwig and S. Petters and M. Stelzer and O. von Stryk and D. Thomas},
title = {Darmstadt Dribblers 2005: Humanoid Robot (Team Description Paper)},
year = {2005},
note = {10 pages},
institution = {Technische Universität Darmstadt},
abstract = {This paper describes the hardware and software design of the two humanoid robot systems of the Darmstadt Dribblers. The robots are used as a vehicle for research in control of locomotion and behavior of humanoid robots with many degrees of freedom and many actuated joints. The Humanoid League of RoboCup provides an ideal testbed for such aspects of dynamics in motion and autonomous behavior as the problem of generating and maintaining statically or dynamically stable bipedal locomotion is predominant for all types of motions during a soccer game. A new modular software architecture has been developed for efficient and effective implementation and test of modules for sensing, planning, behavior, and actions.},
}
@INPROCEEDINGS{kiener05,
author = { Jutta Kiener and Sebastian Petters and Dirk Thomas and Martin Friedmann und Oskar von Stryk},
title = {Architektur und Komponenten für ein heterogenes Team kooperierender, autonomer humanoider Roboter},
year = {2005},
number = {19},
pages = {3 - 10},
month = {08 - 09 December},
publisher = {Springer},
editor = {P. Levi and M. Schanz and R. Lafrenz and V. Avrutin},
series = {Informatik aktuell},
address = {Stuttgart},
booktitle = {Autonome Mobile Systeme 2005 },
organization = {Gesellschaft f\"ur Informatik},
abstract = {Für ein kooperierendes Team autonomer, humanoider Roboter, das derzeit aus insgesamt vier unterschiedlichen, ca. 37 - 68 cm großen Robotertypen besteht, werden eine plattformübergreifende, modulare Softwarearchitektur sowie plattformübergreifende und individuelle Module zur Sensordatenverarbeitung, Planung und Bewegungssteuerung entwickelt. Das entwickelte funktionale Framework ermöglicht die Kommunikation der Softwaremodule, d.h. Algorithmen für die unterschiedlichen Aufgaben innerhalb der Architektur untereinander, sowie die Kommunikation per WLAN zwischen verschiedenen Rechnern und Robotern. Als Anwendungsszenario für die Teamkooperation in einer dynamischen und strukturierten Umgebung wird Roboterfußball untersucht. Die entwickelten Methoden wurden im Juli 2005 von den Darmstadt Dribblers beim RoboCup in Osaka bei der Premiere von Teamspielen in der Humanoid Robot League eingesetzt. Daneben werden Kooperationsszenarien von heterogenen Robotersystemen bestehend aus vierbeinigen und humanoiden Robotern untersucht.},
}
@ARTICLE{KlugMoehlvonStrykBarth:2005,
author = {S. Klug and B. Möhl and O. von Stryk and O. Barth},
title = {Der bionische Roboterarm},
journal = {Konstruktion},
year = {2005},
pages = {48-49},
month = {May},
}
@INPROCEEDINGS{RettigvonStryk:2005,
author = {U. Rettig and O. von Stryk},
title = {Optimal and robust damping control for semi-active vehicle suspension},
year = {2005},
pages = {paper no. 20-316},
month = {August 7-12},
address = {Eindhoven, The Netherlands},
booktitle = {5th EUROMECH Nonlinear Dynamics Conference (ENOC)},
abstract = {The paper focusses on optimal control issues arising in semi-active vehicle suspension motivated by the application of continuously controllable ERF-shock absorbers. Optimality of the damping control is measured by an objective consisting of a weighted sum of criteria related to safety and comfort which depend on the state variables of the vehicle dynamics model. In the case of linear objectives and linear quarter or half car dynamics models the well-known linear quadratic regulators can be computed. However, to account for maximum robustness with respect to unknown perturbations, e.g., by the ground, linear robust-optimal H-infinity controllers are investigated which can be computed iteratively. The linear H-infinity controller can be viewed as the solution of a linear dynamic zero-sum differential game. Thus, a nonlinear H-infinity controller can be obtained in principle as the solution of a nonlinear zero-sum dynamic game problem. Such a problem formulation enables to consider nonlinear vehicle dynamics as well as nonlinear objectives and constraints. A computational method is discussed which computes approximations of robust-optimal trajectories for nonlinear damping control. The method is based on a reformulation of the dynamic game and the application of a control and state parameterization approach in combination with sparse nonlinear programming methods. Numerical results for the different approaches and their validation by software-in-the-loop simulation using a full motor vehicle dynamics model are presented. },
}
@ARTICLE{RoefervonStryk:2005,
author = {Th. Röfer and O. von Stryk},
title = {Softwarearchitektur: Ein Erfolgsfaktor beim Roboterfußball!},
journal = {OBJEKTspektrum},
year = {2005},
volume = {2005},
number = {4},
pages = {31-32},
month = {July/August},
abstract = {Seit 1997 wird jährlich der RoboCup, die Fußballweltmeisterschaft autonomer Roboter, in mehreren Ligen laufender, rollender oder simulierter Roboter ausgetragen. Am RoboCup 2004 in Lissabon, an dem 346 Teams aus 37 Ländern teilnahmen, hat erstmals ein deutsches Team den Weltmeistertitel in der Liga der vierbeinigen Roboter gewonnen. Das GermanTeam will den Titel auch beim diesjährigen RoboCup im Juli in Osaka verteidigen.},
}
@INPROCEEDINGS{StelzervonStryk2005,
author = {Maximilian Stelzer and Oskar von Stryk},
title = {From Robots to Humans: Towards Efficient Forward Dynamics Simulation and Optimization Exploiting Structure and Sensitivity Information},
year = {2005},
booktitle = {Proceedings of ECCOMAS Multibody Dynamics 2005, Advances in Computational Multibody Dynamics, Madrid, June 21-24},
}
@ARTICLE{Butz-etal:2004,
author = {T. Butz and M. Ehmann and T.-M. Wolter and O. von Stryk},
title = {Realistische Straßenmodellierung für die Fahrdynamiksimulation in Echtzeit},
journal = {ATZ},
year = {2004},
volume = {2/2004, Jahrgang 106},
pages = {118-125},
url = {http://www.all4engineers.de/},
}
@TECHREPORT{DD:2004,
author = {J. Kiener and M. Stelzer and O. von Stryk},
title = {Darmstadt Dribblers 2004: Humanoid Robot (Team Description Paper)},
year = {2004},
note = {9 pages},
institution = {Technische Universität Darmstadt},
url = {http://www.sim.informatik.tu-darmstadt.de/},
abstract = {This paper describes the design and implementation of the first humanoid robot prototype of the Darmstadt Dribblers, which participated in the Humanoid League of RoboCup for the first time in 2004. The robot is used as a vehicle for research in control of locomotion and behavior of humanoid robots with many degrees of freedom and many actuated joints. For humanoid robots highly nonlinear physical dynamical effects must be considered on all levels of a reactive-deliberative control architecture realizing autonomous robot behaviour. The Humanoid League of RoboCup provides an ideal testbed as the problem of generating and maintaining statically or dynamically stable bipedal locomotion is predominant for all types of motions during a soccer game. The team has evolved from the Darmstadt Dribbling Dackels team which continuously has participated as part of the German Team in the Sony Four-Legged League since 2001.},
}
@ARTICLE{Glocker:04,
author = {M. Glocker},
title = {A decomposition approach for optimal control problems with integer inner point state constraints},
journal = {Proceedings in Applied Mathematics and Mechanics (PAMM)},
year = {2004},
volume = {4},
number = {1},
pages = {608-609},
month = {Dec.},
note = {Beitrag zur GAMM-Jahrestagung 2004 in Dresden, eingereicht zur Veröffentlichung in PAMM},
abstract = {A large class of optimal control problems for hybrid dynamic systems can be formulated as mixed-integer optimal control problems (MIOCPs). A decomposition approach is suggested to solve a special subclass of MIOCPs with mixed integer inner point state constraints. It is the intrinsic combinatorial complexity of the discrete variables in addition to the high nonlinearity of the continuous optimal control problem that forms the challenges in the theoretical and numerical solution of MIOCPs.
During the solution procedure the problem is decomposed at the inner time points into a multiphase problem with mixed integer boundary constraints and phase transitions at unknown switching points. Due to a discretization of the state space at the switching points the problem can be decoupled into a family of continuous optimal control problems (OCPs) and a problem similar to the asymmetric group traveling salesman problem (AGTSP).
The OCPs are transcribed by direct collocation to large-scale nonlinear programming problems, which are solved efficiently by an advanced SQP method. The results are used as weights for the edges of the graph of the corresponding TSP-like problem, which is solved by a Branch-and-Cut-and-Price (BCP) algorithm.
The proposed approach is applied to a hybrid optimal control benchmark problem for a motorized traveling salesman.},
}
@TECHREPORT{GT:2004,
author = {T. Röfer and T. Laue and H.-D. Burkhard and J. Hoffmann and M. Jüngel and D. Göhring and M. Lötzsch and U. Düffert and M. Spranger and B. Altmeyer and V. Goetzke and O. von Stryk and R. Brunn and M. Dassler and M. Kunz and M. Risler and M. Stelzer and D. Thomas and S. Uhrig and U. Schwiegelshohn and I. Dahm and M. Hebbe and W. Nistico and C. Schumann and M. Wachter},
title = {GermanTeam 2004, Technical Report of the RocoCup-Team in the Sony Legged Robot League},
year = {2004},
note = {299 pages},
institution = {HU-Berlin, U-Bremen, TU-Darmstadt, U-Dortmund},
abstract = {The GermanTeam is a joint project of four German universities in the Sony Legged Robot League. This report describes the software developed for the RoboCup 2004 in Lisbon. It presents the software architecture of the system as well as the methods that were developed to tackle the problems of motion, image processing, object recognition, self-localization, and robot behavior. The approaches for both playing robot soccer and mastering the challenges are presented. In addition to the software actually running on the robots, this document will also give an overview of the tools the GermanTeam used to support the development process.
The report serves as detailed documentation of the work that has been done and aims at enabling other researchers to make use of it. In an extensive appendix, several topics are described in detail, namely the installation of the software, how it is used, the implementation of inter-process communication, streams, and debugging mechanisms, and the approach of the GermanTeam to model the behavior of the robots.},
}
@INPROCEEDINGS{HoeplerStelzervonStryk:2004,
author = {R. Höpler and M. Stelzer and O. von Stryk},
title = {Integrated, object-oriented dynamics modeling for design, trajectory optimization and control of legged robots},
year = {2004},
month = {March 1-4},
address = {Halle (Saale), Germany},
booktitle = {EUROMECH Colloquium 452 on Advances in Simulation Techniques for Applied Dynamics},
}
@TECHREPORT{Kiener:2004,
author = {J. Kiener},
title = {Direkte und Inverse Kinematik eines sechsgelenkigen humanoiden Roboterarms},
year = {2004},
note = {Interner Bericht},
institution = {Technische Universität Darmstadt, Fachgebiet Simulation und Systemoptimierung},
}
@INPROCEEDINGS{MechRob:2004,
author = {R. Höpler and M. Stelzer and O. von Stryk},
title = {Object-oriented dynamics modeling for legged robot trajectory optimization and control},
year = {2004},
pages = {972-977},
month = {Sept. 13-15},
publisher = {Sascha Eysoldt Verlag},
address = {Aachen},
booktitle = {Proc. IEEE Intl. Conf. on Mechatronics and Robotics (MechRob)},
abstract = {This paper discusses the development and application of object-oriented modeling and implementation techniques to achieve a representation of the mechanical model amenable to the various requirements by legged robot applications. This leads to a uniform, modular, and flexible code generation while reaping the performance of efficient domain-specific articulated body algorithms. Trajectory optimization problems of bipedal and quadrupedal robots are investigated as applications. It is shown how a high-level specification of multibody dynamics models using component libraries serves as a basis for generation of a number of modules forming an ìoverall computational dynamics model. The selected examples illustrate how one copes with the emerging complexity by integrating various modules for, e.g., equations of motion, non-linear boundary conditions, symmetry and transition conditions, for multiple phases during motion. Variations of the mechanical structure, e.g., contact conditions can be treated either by multiple models or by reconfiguration of one model. Numerical results are presented for time- and energy-optimal trajectories of full three-dimensional models of a humanoid robot and a Sony four-legged robot. },
}
@INCOLLECTION{tropea:bionik2004,
author = {M. Stelzer and O. von Stryk},
title = {Laufbewegungen bei Roboter, Tier und Mensch: Analyse, Modellierung, Simulation und Optimierung},
year = {2004},
pages = {145-158},
publisher = {Springer-Verlag},
editor = {T. Rossmann and C. Tropea},
booktitle = {Bionik},
url = {http://www.springeronline.com/sgw/cda/frontpage/0,11855,1-185-22-32104490-detailsPage%253Dppmmedia%257CaboutThisBook%257CaboutThisBook,00.html},
}
@INPROCEEDINGS{BussHardtetal.Humanoids:2003,
author = {M. Buss and M. Hardt and J. Kiener and M. Sobotka and M. Stelzer and O. von Stryk and D. Wollherr},
title = {Towards an autonomous, humanoid, and dynamically walking robot: modeling, optimal trajectory planning, hardware architecture, and experiments},
year = {2003},
pages = {to appear},
month = {Sept. 30 - Oct. 3},
publisher = {Springer Verlag},
address = {Karlsruhe, München},
booktitle = {Third IEEE International Conference on Humanoid Robots},
abstract = {The complete development process for achieving walking motion with a recently constructed humanoid robot is discussed. The desired motion is based on the solution of an optimal control problem whose constraints depend upon the high-dimensional nonlinear multibody system dynamics of a 17~DoF humanoid and physical contact constraints with the environment. On-line control strategies are developed for tracking the precalculated trajectories. Experimental walking results with the humanoid robot are presented.},
}
@TECHREPORT{GT:2003,
author = {T. Röfer and H.-D. Burkhard and U. Düffert and J. Hoffmann and D. Göhring and M. Jüngel and M. Lötzsch and O. von Stryk and R. Brunn and M. Kallnik and M. Kunz and S. Petters and M. Risler and M. Stelzer and I. Dahm and M. Wachter and K. Engel and A. Osterhues and C. Schumann and J. Ziegler},
title = {GermanTeam 2003},
year = {2003},
note = {199 pages},
type = {Technical Report of the RocoCup-Team in the Sony Legged Robot League},
institution = {Humboldt-Universität Berlin, Universität Bremen, Technische Universität Darmstadt, Universität Dortmund},
owner = {SIM},
abstract = {The GermanTeam is a joint project of several German universities in the Sony Legged Robot League. This report describes the software developed for the RoboCup 2003 in Padova. It presents the software architecture of the system as well as the methods that were developed to tackle the problems of motion, image processing, object recognition, self-localization, and robot behavior. The approaches for both playing robot soccer and mastering the challenges are presented. In addition to the software actually running on the robots, this document will also give an overview of the tools the GermanTeam used to support the development process.
In an extensive appendix, several topics are described in detail, namely the installation of the software, how it is used, the implementation of inter-process communication, streams, and debugging mechanisms, and the approach of the GermanTeam to model the behavior of the robots.},
}
@TECHREPORT{GTTDP:2003,
author = {I. Dahm and U. Düffert and J. Hoffmann and M. Jüngel and M. Kallnik and M. Lötzsch and M. Risler and T. Röfer and M. Stelzer and J. Ziegle},
title = {German Team 2003},
year = {2003},
note = {4 Seiten},
type = {Team Description Paper},
institution = {Humboldt-Universität Berlin, Universität Bremen, Technische Universität Darmstadt},
owner = {SIM},
abstract = {The GermanTeam participates as a national team in the Sony Legged Robot League. It currently consists of students and researchers from the following four universities: the Humboldt-Universität zu Berlin, the Universität Bremen, the Technische Universität Darmstadt, and the Universität Dortmund. The members of the GermanTeam participate as separate teams in the national contests such as RoboCup German Open, but jointly line up for the international RoboCup championship as a single team. To support this cooperation and concurrency, the GermanTeam introduced an architecture that provides mechanisms for parallel development. The entire information processing and control of the robot is divided into modules that have well-defined tasks and interfaces. For each module, many different solutions can be developed. Solutions for a module can be switched at runtime. Currently, for most modules various solutions exist. Approaches to a problem can thereby easily be compared and benchmarked.
This paper gives a brief overview of the current work of all four universities in the GermanTeam.},
}
@ARTICLE{HardtvonStryk2003,
author = {M. Hardt and O. von Stryk},
title = {Dynamic modeling in the simulation, optimization and control of legged robots},
journal = {ZAMM: Zeitschrift für Angewandte Mathematik und Mechanik},
year = {2003},
volume = {83},
number = {10},
pages = {648-662},
url = {http://www.wiley-vch.de/publish/en/journals/alphabeticIndex/2233/},
owner = {SIM},
abstract = {Fundamental principles and recent methods for investigating the nonlinear dynamics of legged robot motions with respect to control, stability and design are discussed. One of them is the still challenging problem of producing dynamically stable gaits. The generation of fast walking or running motions requires methods and algorithms adept at handling the nonlinear dynamical effects and stability issues which arise. Reduced, recursive multibody algorithms, a numerical optimal control method, and new stability and energy performance indices are presented which are well-suited for this purpose.Difficulties and open problems are discussed along with numerical investigations into the proposed gait generation scheme. Our analysis considers both biped and quadrupedal gaits. },
}
@INPROCEEDINGS{ICRA:2003,
author = {M. Hardt and O. von Stryk and D. Wollherr and M. Buss},
title = {Development and control of autonomous, biped locomotion using efficient modeling, simulation, and optimization techniques},
year = {2003},
pages = {1356--1361},
month = {Sept. 14-19},
address = {Taipeh, Taiwan},
booktitle = {Proc. IEEE Int. Conf. on Robotics and Automation (ICRA)},
url = {http://www.icra2003.org/},
abstract = {Methods for modeling, simulating and optimizing the dynamics, stability and performance of legged robot locomotion are discussed in this paper. It is demonstrated how these tools are used in the design, implementation and operation of a humanoid robot. The selection and integration of fundamental hard- and software needed for autonomous operation and high agility is presented for a recently developed fully-actuated 17 DoF humanoid. The results are additionally reported from simulations and gait optimizations completed during its development using a 3D dynamic biped model coupled with multiple physical and stability constraints.},
}
@INPROCEEDINGS{PAMM:2003,
author = {A. Helm and M. Hardt and R. Höpler and O. von Stryk},
title = {Development of a toolbox for model-based real-time simulation and analysis of legged robots},
year = {2003},
volume = {2},
number = {1},
pages = {130-131},
month = {25 March},
booktitle = {PAMM - Proceedings in Applied Mathematics and Mechanics},
doi = {10.1002/pamm.200310050},
url = {http://www3.interscience.wiley.com/cgi-bin/jhome/91016652},
abstract = {Multibody systems such as legged robots require sophisticated and efficient methods for their modeling, control and simulation. This paper discusses the development of a software library based on modern tools such as C++, OpenGL and XML for highly efficient dynamics modeling. A primary focus lies on modularity permitting its easy extensibility in connection with different actuation and contact models, optimization algorithms, localized and centralized on-line control schemes as well as animation and simulation environments.},
}
@INPROCEEDINGS{RC:2002,
author = {M. Hardt and O. von Stryk},
title = {The role of motion dynamics in the design, control and stability of bipedal and quadrupedal robots},
year = {2003},
volume = {2752},
pages = {206-223},
month = {June 24-25},
publisher = {Springer-Verlag},
editor = {G.A. Kaminka and P.U. Lima and R. Rojas},
series = {Lecture Notes in Artificial Intelligence},
address = {Fukuoka, Japan},
booktitle = {RoboCup 2002 International Symposium (Robot Soccer World Cup VI)},
abstract = {Fundamental principles and recent methods for investigating the nonlinear dynamics of legged robot motions with respect to control, stability and design are discussed. One of them is the still challenging problem of producing dynamically stable gaits. The generation of fast walking or running motions require methods and algorithms adept at handling the nonlinear dynamical effects and stability issues which arise. Reduced, recursive multibody algorithms, a numerical optimal control package, and new stability and energy performance indices are presented which are well-suited for this purpose. Difficulties and open problems are discussed along with numerical investigations into the proposed gait generation scheme. Our analysis considers both biped and quadrupedal gaits with particular reference to the problems arising in soccer-playing tasks encountered at the RoboCup where our team, the Darmstadt Dribbling Dackels, participates as part of the German Team in the Sony Legged Robot League.},
}
@INPROCEEDINGS{StelzerHardtvonStryk2003,
author = {M. Stelzer and M. Hardt and O. von Stryk},
title = {Efficient dynamic modeling, numerical optimal control and experimental results for various gaits of a quadruped robot},
year = {2003},
pages = {601-608},
month = {Sept. 17-19},
booktitle = {CLAWAR 2003: 6th International Conference on Climbing and Walking Robots, Catania, Italy},
owner = {SIM},
abstract = {Numerical simulation and optimization of gaits for quadruped robots based on nonlinear multibody dynamics models of legged locomotion have made progress recently. A fully threedimensional dynamical model of Sony’s four-legged robot is used to state an optimal control problem for a symmetric, dynamically stable gait. The optimal control problem is solved by a sparse direct collocation method. Numerical problems related to the high-index differential algebraic equations of motion are avoided by substituting the differential algebraic equations by an equivalent set of reduced dynamics ordinary differential equations. Numerical and experimental results validate the model and the methods used for gait generation.},
}
@INCOLLECTION{VoegelvonStrykBulirschWolterChucholowski2003,
author = {M. Vögel and O. von Stryk and R. Bulirsch and T.-M. Wolter and C. Chucholowski},
title = {An optimal control approach to real-time vehicle guidance},
year = {2003},
pages = {84-102},
publisher = {Springer-Verlag},
editor = {W. Jäger and H.-J. Krebs},
booktitle = {Mathematics - Key Technology for the Future},
owner = {SIM},
abstract = {A newly developed two-level driver model is presented. On the anticipation level, optimal control problems for a reduced vehicle dynamics model are solved repeatedly on a moving prediction horizon to yield near optimal setpoint trajectories for the full model. On the stabilization level, a nonlinear position controller is developed to accurately track the setpoint trajectories with a full motor vehicle dynamics model in real-time. The formulation of the optimal control problems on the anticipation level is based on a nonlinear single track model which is extended by a complex tire model and further nonlinear model details such as to match the main properties of the full vehicle dynamics model. The optimal control problems are solved efficiently by a recently developed sparse direct collocation method. Numerical results for various vehicle maneuvers are presented, including a time-optimal double lane change at high speed.},
}
@BOOK{vonStryk:Habil,
author = {O. von Stryk},
title = {Numerical Hybrid Optimal Control and Related Topics},
year = {2003},
publisher = {Habilitationsschrift, Technische Universität München},
editor = { },
address = {München, Germany},
}
@INPROCEEDINGS{wollherr:aim03,
author = {D. Wollherr and M. Buss and M. Hardt and O. von Stryk},
title = {Research and Development Towards an Autonomous Biped Walking Robot},
year = {2003},
pages = {968--973},
address = {Kobe, Japan},
booktitle = {Proceedings of the IEEE/ASME International Conference on Advanced Intelligent Mechatronics AIM2003},
}
@TECHREPORT{ZulaufKieferEffenberger:2003,
author = {A. Zulauf and M. Kiefer and J. Effenberger},
title = {Entwicklung eines Roboterarms und eines Kamerasystems für einen mobilen Roboter},
year = {2003},
type = {Studienarbeit},
institution = {Technische Universität Darmstadt, Fachgebiet Simulation und Systemoptimierung},
}
@INPROCEEDINGS{BussHardtvonStryk:2002,
author = {M. Buss and M. Hardt and O. von Stryk},
title = {Numerical solution of hybrid optimal control problems with applications in robotics},
year = {2002},
pages = {2077-2082},
month = {July 21-26},
publisher = {Elsevier Science},
address = {Barcelona, Spain},
booktitle = {Proc. 15th IFAC World Congress on Automatic Control},
keywords = {hybrid optimal control, mechatronics, underactuated robots},
url = {http://www.ifac2002.org/},
abstract = {Numerical solution techniques for a class of hybrid (discrete event / continuous variable) optimal control problems (HOCP) are described, and their potential use in robotic applications is demonstrated. HOCPs are inherently combinatorial due to their discrete event aspect which is one of the main challenges when numerically solving for optimal hybrid trajectories. One may associate a continuous nonlinear multi-phase problem with each possible discrete state sequence. Two solution techniques for obtaining suboptimal solutions are presented (both based on numerical direct collocation): one fixes interior point constraints on a grid, another uses branch-and-bound. Numerical results of a robotic multi-arm transport task and an underactuated robot are presented.},
}
@INPROCEEDINGS{GlockervonStryk:2002,
author = {M. Glocker and O. von Stryk},
title = {Hybrid optimal control of motorized traveling salesmen and beyond},
year = {2002},
pages = {987-992},
month = {July 21-26},
publisher = {Elsevier Science},
address = {Barcelona, Spain},
booktitle = {Proc. 15th IFAC World Congress on Automatic Control},
keywords = {nonlinear hybrid dynamical systems, mixed-integer optimal control, branch-and-bound, direct collocation transcription, sparse sequential quadratic programming, motorized traveling salesmen, genetic algorithm},
url = {http://www.ifac2002.org/},
abstract = {Numerical methods for optimal control of hybrid dynamical systems are considered where the discrete dynamics and the nonlinear continuous dynamics are tightly coupled. A decomposition approach for numerically solving general mixed-integer continuous optimal control problems (MIOCPs) is discussed. In the outer optimization loop a branch-and-bound binary tree search is used for the discrete variables. The multiple-phase optimal control problems for the continuous state and control variables in the inner optimization loop are solved by a sparse direct collocation transcription method. A genetic algorithm is applied to improve the performance of the branch-and-bound approach by providing a good initial upper bound on the MIOCP performance index. Results are presented for motorized traveling salesmen problems, new benchmark problems in hybrid optimal control.},
}
@TECHREPORT{GT:2002,
author = {H.-D. Burkhard and U. Düffert and J. Hoffmann and M. Jüngel and M. Lötzsch and R. Brunn and M. Kallnik and N. Kuntze and M. Kunz and S. Petters and M. Risler and O. v. Stryk and N. Koschmieder and T. Laue and T. Röfer and K. Spiess and A. Cesarz and I. Dahm and M. Hebbel and W. Nowak and J. Ziegler},
title = {German Team 2002},
year = {2002},
note = {178 Seiten},
type = {Technical Report of the RocoCup-Team in the Sony Legged Robot League},
institution = {Humboldt-Universität Berlin, Universität Bremen, Technische Universität Darmstadt},
}
@INPROCEEDINGS{hardt:clawar02,
author = {M. Hardt and D. Wollherr and M. Buss and O. von Stryk},
title = {Design of an autonomous fast-walking humanoid robot},
year = {2002},
pages = {391-398},
month = {Sept. 25-27},
publisher = {Bury St. Edmunds and London, UK: Professional Engineering Publishing},
editor = {P. Bidaud and F.B. Amar},
address = {Paris, France},
booktitle = {CLAWAR: International Conference on Climbing and Walking Robots},
abstract = {The design considerations for a small, relatively fast walking, autonomous humanoid robot are presented. The robot must be energy efficient but also produce sufficient torque to reach greater speeds. On the basis of previous investigations into gait optimization for multilegged systems, dynamical modeling and nonlinear optimization tools are used for design optimization and choosing the motor size and gear ratios. Gait trajectories for relatively fast steps and different prototypes were calculated. The design decisions are described for the humanoid robot with 6 degrees-of-freedom (DoF) in each leg and 2 DoF in each arm based on numerical results and preliminary investigations with a 4 DoF test robot.},
}
@INPROCEEDINGS{IFAC:2002,
author = {M. Hardt and O. von Stryk},
title = {Increasing stability in dynamic gaits using numerical optimization},
year = {2002},
pages = {1636-1641},
month = {July 21-26},
publisher = {Elsevier Science},
address = {Barcelona, Spain},
booktitle = {Proc. 15th IFAC World Congress on Automatic Control},
keywords = {walking, path planning, dynamic stability, robot dynamics, optimization problems, nonlinear programming, numerical methods},
url = {http://www.ifac2002.org/},
abstract = {Optimal gait planning is applied in this work to the problem of improving stability in quadruped locomotion. In many settings, it is desired to operate legged machines at high performance levels where rapid velocities and a changing environment make stability of utmost concern. Since gait planning still remains a vital component of legged system control design, an efficient method of determining periodic paths is presented which optimize a dynamic stability criterion. Efficient recursive multibody algorithms are used with numerical optimal control software to solve the minimax performance stability criteria.},
}
@INPROCEEDINGS{IROS:2002,
author = {D. Wollherr and M. Hardt and M. Buss and O. von Stryk},
title = {Actuator selection and hardware realization of a small and fast-moving autonomous humanoid robot},
year = {2002},
pages = {2491-2496},
month = {Sept. 30 - Oct. 4},
address = {Lausanne, Switzerland},
booktitle = {Proc. 2002 IEEE/RSJ Int. Conf. on Intelligent Robots and Systems (IROS)},
url = {http://iros02.epfl.ch/},
abstract = {This paper discusses the design concept and system development of a small and relatively fast walking, autonomous humanoid robot with 17 degrees-offreedom (DoF). The selection of motor size and gear ratios is based on numerical optimization of detailed multibody dynamics and optimal control corresponding to fast steps of the robot with an envisioned target speed of more than 0.5m/s. In this paper the design considerations based on numerical optimal control studies and the mechanical realization of the robot are presented including first investigations on the achievable performance of a decentralized, microcontrollerbased control architecture.},
}
@INPROCEEDINGS{KONDISK:2002,
author = {M. Buss and M. Glocker and M. Hardt and O. von Stryk and R. Bulirsch and G. Schmidt},
title = {Nonlinear hybrid dynamical systems: modeling, optimal control, and applications},
year = {2002},
volume = {279},
pages = {311-335},
publisher = {Springer-Verlag},
editor = {S. Engell, G. Frehse, E. Schnieder},
series = {Lecture Notes in Control and Information Sciences (LNCIS)},
address = {Berlin, Heidelberg},
booktitle = {Modelling, Analysis and Design of Hybrid Systems},
abstract = {Nonlinear hybrid dynamical systems are the main focus of this paper. A modeling framework is proposed, feedback control strategies and numerical solution methods for optimal control problems in this setting are introduced, and their implementation with various illustrative applications are presented. Hybrid dynamical systems are characterized by discrete event and continuous dynamics which have an interconnected structure and can thus represent an extremely wide range of systems of practical interest. Consequently, many modeling and control methods have surfaced for these problems. This work is particularly focused on systems for which the degree of discrete/continuous interconnection is comparatively strong and the continuous portion of the dynamics may be highly nonlinear and of high dimension. The hybrid optimal control problem is defined and two solution techniques for obtaining suboptimal solutions are presented (both based on numerical direct collocation for continuous dynamic optimization): one fixes interior point constraints on a grid, another uses branch-and-bound. These are applied to a robotic multi-arm transport task, an underactuated robot arm, and a benchmark motorized traveling salesman problem.},
}
@INPROCEEDINGS{LNCSE:2002,
author = {T. Butz and O. von Stryk and C. Chucholowski and S. Truskawa and T.-M. Wolter},
title = {Modeling techniques and parameter estimation for the simulation of complex vehicle structures},
year = {2002},
volume = {21},
pages = {333-340},
publisher = {Springer-Verlag},
editor = {M. Breuer, F. Durst, C. Zenger},
series = {Lecture Notes in Computational Science and Engineering},
booktitle = {High Perfomance Scientific and Engineering Computing},
}
@ARTICLE{TF:2002,
author = {M. Hardt and M. Stelzer and O. von Stryk},
title = {Modellierung und Simulation der Dynamik des Laufens bei Roboter, Tier und Mensch},
journal = {thema Forschung},
year = {2002},
volume = {2/2002},
pages = {56-63},
url = {http://www.tu-darmstadt.de/for/thema_forschung/thema-forschung.tud},
abstract = {In den neunziger Jahren des zwanzigsten Jahrhunderts begann weltweit das wissenschaftliche und kommerzielle Interesse an Laufmaschinen und laufenden Robotern (z.B. Honda P3, Sony AIBO) stark anzuwachsen. Konstruktion, Steuerung und Regelung laufender Roboter sind um ein Vielfaches aufwendiger zu realisieren als beispielsweise die Fortbewegung auf Rädern. Die Fortbewegung auf Beinen ermöglicht jedoch das Schreiten über Hindernisse und Gräben, das Treppen steigen und allgemein eine gleichmäßige Fortbewegung über unebenem Untergrund durch Kompensation von Unebenheiten durch Anpassung von Schrittlänge und -höhe. Auch besteht auf weichem Grund ein geringeres Risiko des Einsinkens gegenüber Rädern. Computerbasierte Modellierung und Simulation bietet neben Theorie und Experiment einen neuen Zugang zum Verständnis und zur Lösung vieler noch offener, grundlegender Fragen im Verständnis der Dynamik des Laufens bei Mensch, Tier und Roboter.},
}
@ARTICLE{TF:2002-2,
author = {T. Butz and C. Chucholowski and M. Ehmann and U. Rettig and O. von Stryk and T.-M. Wolter},
title = {Test und Validierung von Fahrdynamikregelungen mittels Hardware- und Software-in-the-Loop Simulation},
journal = {thema Forschung},
year = {2002},
volume = {1/2002},
pages = {45-50},
}
@ARTICLE{ZAMM:2002,
author = {T. Butz and O. von Stryk},
title = {Modelling and simulation of electro- and magnetorheological fluid dampers},
journal = {ZAMM: Zeitschrift für Angewandte Mathematik und Mechanik},
year = {2002},
volume = {82},
number = {1},
pages = {3-20},
url = {http://www.wiley-vch.de/publish/en/journals/alphabeticIndex/2233/},
abstract = {Electro- and magnetorheological fluids are smart, synthetic fluids changing their viscosity from liquid to semi-solid state within milliseconds if a sufficiently strong electric or magnetic field is applied. When used in suitable devices, they offer the innovative potential of very fast, adaptively controllable interfaces between mechanical devices and electronic control units. This paper gives an overview on the basic properties of electro- and magnetorheological fluids and discusses various phenomenological models for whole devices and their applications. Numerical simulation results are presented for the passive suspension of a quarter vehicle model.},
}
@INPROCEEDINGS{AISDG:2001,
author = {M.H. Breitner and U. Rettig and O. von Stryk},
title = {On optimal missile guidance upgrades with dynamic Stackelberg game linearizations},
year = {2001},
volume = {6},
pages = {277-294},
publisher = {Boston, Basel, Berlin: Birkhäuser},
editor = {E. Altman, O. Pourtallier},
booktitle = {Advances in Dynamic Games and Applications. Annals of the International Society of Dynamic Games},
}
@INPROCEEDINGS{CACE:2001,
author = {A. Kröner and T. Kronseder and G. Engl and O. von Stryk},
title = {Dynamic optimization for air separation plants},
year = {2001},
pages = {433-438},
month = {May 27-30},
publisher = {Elsevier},
editor = {R. Gani, S.B. Jorgensen},
address = {Kolding, Dänemark},
booktitle = {Proc. European Symposium on Computer Aided Process Engineering (ESCAPE-11)},
}
@TECHREPORT{GT:2001,
author = {H.-D. Burkhard and U. Düffert and M. Jüngel and M. Lötzsch and N. Koschmieder and T. Laue and T. Röfer and K. Spiess and O. von Stryk and A. Sztybryc and R. Brunn and M. Risler},
title = {GermanTeam 2001},
year = {2001},
note = {41 Seiten},
type = {Technical Report of the RocoCup-Team in the Sony Legged Robot League},
institution = {Humboldt-Universität Berlin, Universität Bremen, Technische Universität Darmstadt},
abstract = {The GermanTeam is a joint project of several German universities in the Sony Legged Robot League. This report describes the software developed for the RoboCup 2001 in Seattle. It presents the software architecture of the system as well as the methods that were developed to tackle the problems of motion, image processing, object recognition, self-localization, and robot behavior. The approaches for both playing robot soccer and mastering the challenges are presented. In addition to the software actually running on the robots, this document will also give an overview of the tools the GermanTeam used to support the development process.},
}
@INPROCEEDINGS{ISNM:2001,
author = {U. Rettig and O. von Stryk},
title = {Numerical optimal control strategies for semi-active vehicle suspension with electrorheological fluid dampers},
year = {2001},
volume = {138},
pages = {221-241},
publisher = {Birkhäuser Verlag},
editor = {K.-H. Hoffmann, R.H.W. Hoppe, V. Schulz},
series = {International Series in Numerical Mathematics},
booktitle = {Fast Solution of Discretized Optimization Problems},
}
@INPROCEEDINGS{LNAI:2002,
author = {R. Brunn and U. Düffert and M. Jüngel and T. Laue and M. Lötzsch and S. Petters and M. Risler and T. Röfer and K. Spiess and A. Sztybryc},
title = {GermanTeam 2001},
year = {2001},
volume = {2377},
pages = {705-708},
publisher = {Springer-Verlag},
editor = {A. Birk, A. Coradeschi, S. Tadokoro},
booktitle = {RoboCup 2001: Robot Soccer World Cup V. - Lecture Notes in Artificial Intelligence},
abstract = {The GermanTeam is the successor of the Humboldt Heroes who already participated in the Sony Legged Robot League competitions in 1999 and 2000. Because of the strong interest of other German universities, in March 2001, the GermanTeam was founded. It consists of students and researchers of five universities: Humboldt-Universität zu Berlin, Universität Bremen, Technische Universität Darmstadt, Universität Dortmund, and Freie Universität Berlin. However, for the system presented in this document, the Humbold Heroes only had reinforcements from Bremen and Darmstadt. The two other universities will actively participate with the beginning of the winter semester.},
}
@INPROCEEDINGS{LNCSE:2001,
author = {T. Kronseder and O. von Stryk and R. Bulirsch and A. Kröner},
title = {Towards nonlinear model-based predictive optimal control of large-scale process models with application to air separation plants},
year = {2001},
pages = {385-410},
publisher = {Springer Verlag},
editor = {M. Grötschel, S.O. Krumke, J. Rambau},
address = {Heidelberg},
booktitle = {Online Optimization of Large Scale Systems},
url = {http://www.zib.de/dfg-echtzeit/Publikationen/Preprints/Preprint-01-14.html},
}
@INPROCEEDINGS{LNCSE:2001-2,
author = {T. Binder and L. Blank and H.G. Bock and R. Bulirsch and W. Dahmen and M. Diehl and T. Kronseder and W. Marquardt and J.P. Schlöder and O. von Stryk},
title = {Introduction to model based optimization of chemical processes on moving horizons},
year = {2001},
pages = {295-339},
publisher = {Springer Verlag},
editor = {M. Grötschel and S.O. Krumke and J. Rambau},
address = {Heidelberg},
booktitle = {Online Optimization of Large Scale Systems},
}
@ARTICLE{vonStrykGlocker:2001,
author = {O. von Stryk and M. Glocker},
title = {Numerical mixed-integer optimal control and motorized traveling salesmen problems},
journal = {APII-JESA (Journal europeen des systemes automatises - European Journal of Control)},
year = {2001},
volume = {35},
number = {4},
pages = {519-533},
abstract = {A general approach for the numerical solution of hybrid, mixed-integer optimal control problems is presented. In an outer level iteration a branch-and-bound procedure is applied to search the entire feasible discrete variable space. An inner level iteration contains for each actual value of the discrete variable a continuous nonlinear optimal control problem with its nonlinear dynamics defined in multiple phases and phase transitions occuring at unknown switching points (events) which must be solved numerically subject to nonlinear constraints. For this purpose, a robust and efficient direct collocation method is employed that parameterizes both the continuous state and control variables and exploits the sparse structure in the resulting nonlinearly constrained optimization problems. The proposed approach is successfully applied to two new hybrid optimal control benchmark problems for a motorized traveling salesman and for a team of two cooperating, motorized salesmen.},
}
@ARTICLE{BussvonStrykBulirschSchmidt:2000,
author = {M. Buss and O. von Stryk and R. Bulirsch and G. Schmidt},
title = {Towards hybrid optimal control},
journal = {at-Automatisierungstechnik},
year = {2000},
volume = {48},
number = {9},
pages = {448-459},
url = {http://www.oldenbourg.de/cgi-bin/roabstracts?A=1494},
abstract = {In this article a general class of hybrid optimal control problems with continuous and discrete state variables and control inputs is defined. After a brief review of conventional optimal control, major novel challenges resulting from the hybrid nature are discussed. Some application problems are comparatively easy to solve because of the fixed or known sequence of discrete events; however, if the number and the sequence of discrete phases is not known a priori, the solution must then be found among a combinatorial number of possible sequence candidates. The article presents several preliminary approaches to the (numerical) solution of hybrid optimal control problems by hybrid dynamic programming, by decomposition using branch-and-bound, or fixing transversality conditions to obtain suboptimal solutions. The last two methods rely on the capabilities of the direct collocation method DIRCOL to solving multi-phase optimal control problems robustly and efficiently. Results obtained by the proposed methods are presented in two examples: an underactuated robotic system with a holding brake as the discrete component, and a hybrid, motorized traveling salesman problem. },
}
@INPROCEEDINGS{CLAWAR:2000,
author = {M. Hardt and O. von Stryk},
title = {Towards optimal hybrid control solutions for gait patterns of a quadruped},
year = {2000},
pages = {385-392},
month = {Oktober 2 - 4},
publisher = {Bury St. Edmunds and London, UK: Professional Engineering Publishing},
editor = {M. Armada, P. Gonzalez de Santos},
address = {Madrid},
booktitle = {Proc. CLAWAR 2000 - 3rd International Conference on Climbing and Walking Robots},
url = {http://www.iai.csic.es/clawar2000/},
abstract = {We consider the problem of finding optimal gaits for a quadruped robot. Paths are sought which minimize the actuation energy required for walking in an attempt to approximate natural motion. The number of possible gaits for a quadruped is quite large when one considers varied orders of leg motion, different liftoff times, and various ground contact combinations for the legs. The problem is treated as a fully nonlinear optimal hybrid path planning problem on a 22-dimensional state space. Modeling aspects, our numerical approach, and experimental results are discussed in this paper.},
}
@ARTICLE{HeimvonStryk:2000,
author = {A. Heim and O. von Stryk},
title = {Trajectory optimization of industrial robots with application to computer-aided robotics and robot controllers},
journal = {Optimization},
year = {2000},
volume = {47},
pages = {407-420},
}
@INPROCEEDINGS{LAM:2000,
author = {R.H.W. Hoppe and G. Mazurkevitch and U. Rettig and O. von Stryk},
title = {Modeling, simulation and control of electrorheological fluid devices},
year = {2000},
pages = {251-276},
note = {Preprint SFB-438-9917, Sonderforschungsbereich 438, Technische Universität München -- Universität Augsburg (1999), 26 S.},
publisher = {Springer-Verlag},
editor = {H.-J. Bungartz, R.H.W. Hoppe, Chr. Zenger},
booktitle = {Lectures on Applied Mathematics},
url = {http://www-lit.mathematik.tu-muenchen.de/veroeff/html/SFB/992.34006.html},
}
@INPROCEEDINGS{LNCS:2000,
author = {T. Butz and O. von Stryk and T.-M. Wolter},
title = {A parallel optimization scheme for parameter estimation in motor vehicle dynamics},
year = {2000},
volume = {1900},
pages = {829-834},
publisher = {Springer-Verlag},
editor = {A. Bode, T. Ludwig, W. Karl, R. Wismüller},
series = {Lecture Notes in Computer Science},
booktitle = {Euro-Par 2000 - Parallel Processing},
}
@ARTICLE{SIAM:2000,
author = {T. Butz and O. von Stryk and M. Vögel and T.-M. Wolter and C. Chucholowski},
title = {Parallel parameter estimation in full motor vehicle dynamics},
journal = {Cover story of SIAM News/Applications on Advanced Architecture Computers},
year = {2000},
volume = {33},
number = {4},
pages = {1-5},
month = {May},
note = { The video of the article is also available from the SIAM website (http://www.siam.org/siamnews/05-00/animations/)},
}
@INPROCEEDINGS{vonStrykGlocker:2000,
author = {O. von Stryk and M. Glocker},
title = {Decomposition of mixed-integer optimal control problems using branch and bound and sparse direct collocation},
year = {2000},
pages = {99-104},
month = {September 18-19},
publisher = {Shaker},
editor = {S. Engell, S. Kowalewski, J. Zaytoon},
address = {Aachen},
booktitle = {ADPM 2000 - The 4th International Conference on Automation of Mixed Processes: Hybrid Dynamic Systems},
abstract = {A large class of optimal control problems for hybrid dynamic systems can be formulated as mixed-integer optimal control problems (MIOCPs). It is the intrinsic combinatorial complexity, in addition to the nonlinearity of the continuous, multi-phase optimal control problems that is largely responsible for the challenges in the theoretical and numerical solution of MIOCPs. We present a new decomposition approach to numerically solving fairly general MICOPs with binary control variables. A Branch and Bound (B&B) technique is applied to efficiently search the entire discrete solution space performing a truncated binary tree search for the discrete variables maintaining upper and lower bounds on the performance index. The partially relaxed binary variables at an inner node define an optimal control problem with dynamic equations defined in multiple phases. Its global solution provides a lower bound on the performance index for all nodes of the subtree. If the lower bound for a given subtree is greater than the current global upper bound then that entire subtree need no longer be searched. The many optimal control problems with nonlinear, continuous state dynamics defined in multiple phases subject to nonlinear constraints are solved most efficiently by a sparse direct collocation transcription. Hereby, the multi-phase optimal control problem is transcribed to a sparse, large-scale nonlinear programming problem being solved efficiently by a tailored SQP method. Despite the high efficiency of the sparse direct collocation method, the efficiency of the decomposition technique for MIOCPs strongly depends on the determination of good lower and upper bounds on the performance index being used to fathoming entire subtrees throughout the binary tree search. The proposed approach is successfully applied to two new benchmark problems for hybrid optimal control: a motorized traveling salesman and a team of two cooperating, motorized salesmen.},
}
@TECHREPORT{DIRCOL,
author = {O. von Stryk},
title = {User`s Guide for DIRCOL (Version 2.1): A direct collocation method for the numerical solution of optimal control problems},
year = {1999},
month = {November},
address = {Technische Universität Darmstadt},
institution = {Fachgebiet Simulation und Systemoptimierung},
}
@INPROCEEDINGS{LNCSE:1999,
author = {C. Chucholowski and M. Vögel and O. von Stryk and T.-M. Wolter},
title = {Real time simulation and online control for virtual test drives of cars},
year = {1999},
volume = {8},
pages = {157-166},
publisher = {Springer-Verlag},
editor = {H.-J. Bungartz, F. Durst, Chr. Zenger},
booktitle = {High Performance Scientific and Engineering Computing. Lecture Notes in Computational Science and Engineering},
}
@INPROCEEDINGS{LNCSE:1999-2,
author = {G. Engl and A. Kröner and T. Kronseder and O. von Stryk},
title = {Numerical simulation and optimal control of air separation plants},
year = {1999},
volume = {8},
pages = {221-231},
publisher = {Springer-Verlag},
editor = {H.-J. Bungartz, F. Durst, Chr. Zenger},
booktitle = {High Performance Scientific and Engineering Computing. Lecture Notes in Computational Science and Engineering},
}
@TECHREPORT{vonStryk-CCG:1999,
author = {O. von Stryk},
title = {Numerische Verfahren zur Parameteridentifikation in Mehrkörpersystemen},
year = {1999},
month = {March 8-11},
note = {64 pages},
institution = {Manuskript zum Lehrgang TV 1.03 der Carl-Cranz-Gesellschaft e.V., Weßling-Oberpfaffenhofen},
}
@ARTICLE{vonStrykVoegel:1999,
author = {O. von Stryk and M. Vögel},
title = {A guidance scheme for full car dynamics simulations},
journal = {ZAMM: Zeitschrift für angewandte Mathematik und Mechanik},
year = {1999},
volume = {79},
number = {Suppl. 2},
pages = {363-364},
}
@TECHREPORT{KoslikRillvonStrykZampieri:1998,
author = {B. Koslik and G. Rill and O. von Stryk and D. Zampieri},
title = {Active suspension design for a tractor by optimal control methods},
year = {1998},
note = {23 S., Eingereicht bei: Optimal Control, Applications and Methods},
type = {Preprint SFB-438-9801},
institution = {Sonderforschungsbereich 438, Technische Universität München - Universität Augsburg},
keywords = {optimal active suspension; steady-state LQR problem; closed-loop solution; open-loop solution; direct transcription method},
abstract = {An active suspension system for improving the ride comfort and safety of a tractor is investigated. The underlying planar dynamic tractor model and a suitable objective for optimal suspension are introduced. The problem of optimal active suspension leads to a linear-quadratic optimal control problem. Classical Linear-Quadratic Regulator (LQR) theory provides a closed-loop control for the steady state problem which is optimal only for an initial disturbance input from the road. A direct transcription method can handle more general disturbances and models but provides only an open-loop solution, where the time history of the optimal control is given along the optimal trajectory for one type of deterministic disturbance and initial value only. Simulation results for two different road disturbances are given comparing both approaches.},
}
@ARTICLE{vonStryk:1998,
author = {O. von Stryk},
title = {Optimal control of multibody systems in minimal coordinates},
journal = {ZAMM: Zeitschrift für Angewandte Mathematik und Mechanik},
year = {1998},
volume = {78},
number = {Suppl. 3},
pages = {1117-1120},
}
@INPROCEEDINGS{BreitnerRettigvonStryk:1997,
author = {M.H. Breitner and U. Rettig and O. von Stryk},
title = {Robust optimal control with large neural networks emulated on the neuro-computer board SYNAPSE-PC},
year = {1997},
pages = {487-492},
publisher = {Wissenschaft & Technik, Berlin},
editor = {A. Sydow},
booktitle = {Application in Modelling and Simulation},
}
@INPROCEEDINGS{HeimvonStryketal:1996,
author = {A. Heim and O. von Stryk and H.J. Pesch and H. Schäffler and K. Scheuer},
title = {Parameteridentifikation, Bahnoptimierung und Echtzeitsteuerung von Robotern in der industriellen Anwendung},
year = {1997},
pages = {551-564},
publisher = {Springer},
editor = {K.-H. Hoffmann, T. Lohmann, W. Jäger, H. Schunck},
booktitle = {Mathematik - Schlüsseltechnologie für die Zukunft},
url = {http://www.iwr.uni-heidelberg.de/groups/amj/bmbf/bmbf.html},
}
@INPROCEEDINGS{AnzillvonStryk:1994,
author = {W. Anzill and O. von Stryk},
title = {Optimum design of microwave oscillators with minimized phase noise},
year = {1996},
pages = {301-306},
publisher = {J. Wiley & Sons Ltd and B. G. Teubner},
editor = {H. Neunzert},
booktitle = {Progress in Industrial Mathematics at ECMI 94},
}
@TECHREPORT{HeimvonStryk:1996,
author = {A. Heim and O. von Stryk},
title = {Documentation of PAREST - A multiple shooting code for optimization problems in differential-algebraic equations},
year = {1996},
note = {31 Seiten},
type = {Report TUM-M9616},
institution = {Mathematisches Institut, Technische Universität München},
}
@ARTICLE{AnzillvonStrykBulirschRusser:1994,
author = {W. Anzill and O. von Stryk and R. Bulirsch and P. Russer},
title = {Phase noise minimization of microwave oscillators by optimal design},
journal = {IEEE MTT-S Digest, Orlando, Florida, USA},
year = {1995},
pages = {1565-1568},
}
@ARTICLE{BreitnerKoslikvonStrykPesch:1994,
author = {M. H. Breitner and B. Koslik and O. von Stryk and H. J. Pesch},
title = {Iterative design of economic models via simulation, optimization and modeling},
journal = {Mathematics and Computers in Simulation},
year = {1995},
volume = {39},
pages = {527-532},
month = {Feb. 2-4},
}
@BOOK{1994:vonStrykDISSVDI,
author = {O. von Stryk},
title = {Numerische Lösung optimaler Steuerungsprobleme: Diskretisierung, Parameteroptimierung und Berechnung der adjungierten Variablen.},
year = {1994},
number = {441},
publisher = {VDI Verlag},
editor = { },
series = {Fortschritt-Berichte VDI, Reihe 8: Meß-, Steuer- und Regelungstechnik},
address = {Düsseldorf},
pdf_short = {1994-diss-abstract.pdf},
}
@ARTICLE{KiehlvonStryk:1994,
author = {M. Kiehl and O. von Stryk},
title = {Generalized necessary conditions for optimal control problems of Bolza type: theory and application},
journal = {ZAMM: Zeitschrift für Angewandte Mathematik und Mechanik},
year = {1994},
volume = {74},
number = {6},
pages = {T591-T593},
}
@INPROCEEDINGS{vonStryk:1994,
author = {O. von Stryk},
title = {Optimization of dynamic systems in industrial applications},
year = {1994},
pages = {347-351},
month = {Sep. 20-23},
editor = {H. J. Zimmermann},
address = {Aachen, Germany},
booktitle = {Proc. 2nd European Congress on Intelligent Techniques and Soft Computing (EUFIT)},
}
@INPROCEEDINGS{vonStrykSchlemmer:1993,
author = {O. von Stryk and M. Schlemmer},
title = {Optimal control of the industrial robot Manutec r3},
year = {1994},
volume = {115},
pages = {367-382},
publisher = {Basel: Birkhäuser},
editor = {R. Bulirsch, D. Kraft},
booktitle = {Computational Optimal Control, International Series of Numerical Mathematics},
}
@INPROCEEDINGS{BreitnerKoslikvonStrykPesch:1993,
author = {M. H. Breitner and B. Koslik and O. von Stryk and H. J. Pesch},
title = {Optimal control of investment, level of employment and stockkeeping},
year = {1993},
pages = {60-63},
publisher = {Heidelberg: Physica Verlag},
editor = {A. Bachem, U. Derigs, M. Jünger, R. Schrader},
booktitle = {Operations Research "93},
}
@INPROCEEDINGS{BulirschNerzPeschvonStryk:1991,
author = {R. Bulirsch and E. Nerz and H. J. Pesch and O. von Stryk},
title = {Combining direct and indirect methods in optimal control: range maximization of a hang glider},
year = {1993},
volume = {111},
pages = {273-288},
publisher = {Basel: Birkhäuser},
editor = {R. Bulirsch, A. Miele, J. Stoer, K.-H. Well},
booktitle = {Optimal Control - Calculus of Variations, Optimal Control Theory and Numerical Methods, International Series of Numerical Mathematics},
}
@INPROCEEDINGS{vonStryk:1993,
author = {O. von Stryk},
title = {Numerical solution of optimal control problems by direct collocation},
year = {1993},
volume = {111},
pages = {129-143},
publisher = {Birkhäuser},
editor = {R. Bulirsch, A. Miele, J. Stoer, K. H. Well},
series = {International Series of Numerical Mathematics},
address = {Basel},
booktitle = {Optimal Control - Calculus of Variations, Optimal Control Theory and Numerical Methods},
abstract = {By an appropriate discretization of control and state variables, a constrained optimal control problem is transformed into a finite dimensional nonlinear program which can be solved by standard SQP-methods~\\cite{Gilletal1986}. Convergence properties of the discretization are derived. From a solution of this method known as direct collocation, these properties are used to obtain reliable estimates of adjoint variables. In the presence of active state constraints, these estimates can be significantly improved by including the switching structure of the state constraint into the optimization procedure. Two numerical examples are presented.},
}
@ARTICLE{vonStrykPeschBulirsch:1993,
author = {O. von Stryk and H. J. Pesch and R. Bulirsch},
title = {Zeit ist Geld? Nicht für Roboter! },
journal = {Sonderreihe: Forschung für Bayern},
year = {1993},
number = {6},
pages = {22-23},
publisher = {Technische Universität München},
}
@ARTICLE{KiehlvonStryk:1992,
author = {M. Kiehl and O. von Stryk},
title = {Real-time optimization of a hydroelectric power plant},
journal = {Computing},
year = {1992},
volume = {49},
pages = {171-191},
}
@ARTICLE{vonStrykBulirsch:1992,
author = {O. von Stryk and R. Bulirsch},
title = {Direct and indirect methods for trajectory optimization},
journal = {Annals of Operations Research},
year = {1992},
volume = {37},
pages = {357-373},
}