Matthias Fuchs

ICRA Conference 2011 Conference Paper

Catching flying balls and preparing coffee: Humanoid Rollin'Justin performs dynamic and sensitive tasks

• Berthold Bäuml
• Florian Schmidt 0001
• Thomas Wimböck
• Oliver Birbach
• Alexander Dietrich
• Matthias Fuchs
• Werner Friedl
• Udo Frese

The mobile humanoid Rollin'Justin is a versatile experimental platform for research in manipulation tasks. Previously, different state of the art control methods and first autonomous task execution scenarios have been demonstrated. In this video two new applications with challenging task requirements are presented. One is the catching of one or even two flying balls using all of Justin's degrees of freedom. The other is the autonomous preparation of coffee. Both applications need adequate sensors to support local referencing. The required precision in position and timing is realized in software, using the sensor information, taking the varying precision of Justin's kinematic sub-chains into account and handling all timings in sub-millisecond range.

ICRA Conference 2009 Conference Paper

On the kinematic modeling and control of a mobile platform equipped with steering wheels and movable legs

• Paolo Robuffo Giordano
• Matthias Fuchs
• Alin Albu-Schäffer
• Gerhard Hirzinger

Mobile platforms equipped with several steering wheels are known to be omnidirectional, i. e. , able to independently translate and rotate on the plane. As an improvement to this design, the Justin mobile platform also possesses the ability to vary its footprint over time by extending/retracting the wheel legs during motion. In this paper, we discuss the kinematic modeling and control issues for such a platform. The goal is to obtain a tracking controller which is able to realize an arbitrary linear/angular platform motion while, at the same time, independently expanding/retracting each leg. Experimental results support the proposed approach.

ICRA Conference 2009 Conference Paper

Rollin' Justin - Design considerations and realization of a mobile platform for a humanoid upper body

• Matthias Fuchs
• Christoph Borst 0001
• Paolo Robuffo Giordano
• Andreas Baumann
• Erich Krämer
• Jörg Langwald
• Robin Gruber
• Nikolaus Seitz

Research on humanoid robots for use in servicing tasks, e. g. fetching and delivery, attracts steadily more interest. With Rollin' Justin a mobile robotic system and research platform is presented that allows the implementation and demonstration of sophisticated control algorithms and dexterous manipulation. Important problems of service robotics such as mobile manipulation and strategies for using the increased workspace and redundancy in manipulation task can be studied in detail. This paper gives an overview of the design considerations for a mobile platform and their realizations to transform the formerly table-mounted humanoid upper body system Justin into Rollin' Justin, a fully self-sustaining mobile research platform.

ICRA Conference 2009 Conference Paper

Rollin' Justin - Mobile platform with variable base

• Christoph Borst 0001
• Thomas Wimböck
• Florian Schmidt 0001
• Matthias Fuchs
• Bernhard Brunner
• Franziska Zacharias
• Paolo Robuffo Giordano
• Rainer Konietschke

Research on humanoid robots for use in servicing tasks, e. g. fetching and delivery, attracts steadily more interest. With “Rollin' Justin” a mobile robotic system and research platform is presented that allows sophisticated control algorithms and dexterous manipulation. This video gives an overview of the mobile humanoid robotic system “Rollin' Justin” with special emphasis on mechanical design features, control issues and high-level system capabilities such as human robot interaction.

IROS Conference 2008 Conference Paper

The DLR-Crawler: A testbed for actively compliant hexapod walking based on the fingers of DLR-Hand II

• Martin Görner
• Thomas Wimböck
• Andreas Baumann
• Matthias Fuchs
• Thomas Bahls
• Markus Grebenstein
• Christoph Borst 0001
• Jörg Butterfaß

Walking is a fascinating way of locomotion that is very robust, especially in unstructured terrain. Many researchers devote their time to understanding its underlying principles and to build robots based on their findings. Using the fingers of DLR-Hand II a six-legged actively compliant walking robot is developed. It is intended to be used as testbed for the evaluation of different force- and position-based leg and gait control algorithms for hexapod walking in rough terrain. Following a brief overview of the finger hardware, the use of fingers as legs is analyzed and discussed. The body geometry as well as the systems constituting the robot are described. The compliance control algorithm used is explained and finally some experimental results are presented.

IROS Conference 2007 Conference Paper

Dynamics of step-climbing with deformable wheels and applications for mobile Robotics

• Alexander Wilhelm
• William W. Melek
• Jan Paul Huissoon
• Christopher Michael Clark
• Gerhard Hirzinger
• Norbert Sporer
• Matthias Fuchs

Wheeled-mobile robots operating in human environments typically encounter small steps. Surmounting steps is normally not considered when determining peak torque needs, yet it can be the maximum requirement. This work looks at the statics and dynamics of this situation to determine the necessary peak torque. It finds that using a dynamic model that includes the wheel elasticity is essential for properly representing a real-world tire. When torque is increased using a step function, energy is stored in the tire - higher tire elasticity eases climbing. Knowledge of this phenomenon could facilitate the use of smaller actuators. The model is numerically integrated and results are found to agree with experiment.

AAAI Conference 1998 Conference Paper

A Feature-Based Learning Method for Theorem Proving

• Matthias Fuchs

Automatedreasoning or theorem proving essentially amounts to solving search problems. Despite significant progress in recent years theorem provers still have manyshortcomings. The use of machine-learning techniques is acknowledged as promising, but difficult to apply in the area of theorem proving. Wepropose here to learn search-guiding heuristics by employing features in a simple, yet effective manner. Features are used to adapt a heuristic to a solved source problem. The adapted heuristic can then be utilized profitably for solving related target problems. Experiments have demonstrated that the approach not only allows for significant speed-ups, but also makesit possible to prove problems that were out of reach before.

IJCAI Conference 1997 Conference Paper

High Performance ATP Systems by Combining Several Al Methods

• Jorg Denzinger
• Marc Fuchs
• Matthias Fuchs

We present a design for an automated theorem prover that controls its search based on ideas from several areas of artificial intelligence (AI). The combination of case-based reasoning, several similarity concepts, a cooperation concept of distributed AI and reactive planning enables a system to learn from previous successful proof attempts. In a kind of bootstrapping process easy problems are used to solve more and more complicated ones. We provide case studies from two domains in pure equational theorem proving. These case studies show that an instantiation of our architecture achieves a high grade of automation and outperforms state-of-the-art conventional theorem provers.

ICML Conference 1995 Conference Paper

Learning Proof Heuristics by Adaptive Parameters

• Matthias Fuchs