27 research outputs found
Estimating the non-linear dynamics of free-flying objects
This paper develops a model-free method to estimate the dynamics of free-flying objects. We take a realistic perspective to the problem and investigate tracking accurately and very rapidly the trajectory and orientation of an object so as to catch it in flight. We consider the dynamics of complex objects where the grasping point is not located at the center of mass. To achieve this, a density estimate of the translational and rotational velocity is built based on the trajectories of various examples. We contrast the performance of six non-linear regression methods (Support Vector Regression (SVR) with Radial Basis Function (RBF) kernel, SVR with polynomial kernel, Gaussian Mixture Regression (GMR), Echo State Network (ESN), Genetic Programming (GP) and Locally Weighted Projection Regression (LWPR)) in terms of precision of recall, computational cost and sensitivity to choice of hyper-parameters. We validate the approach for real-time motion tracking of 5 daily life objects with complex dynamics (a ball, a fully-filled bottle, a half-filled bottle, a hammer and a pingpong racket). To enable real-time tracking, the estimated model of the object's dynamics is coupled with an Extended Kalman Filter for robustness against noisy sensing. (C) 2012 Elsevier B.V. All rights reserved
Bimanual Interaction with Clothes. Topology, Geometry, and Policy Representations in Robots
Twardon L. Bimanual Interaction with Clothes. Topology, Geometry, and Policy Representations in Robots. Bielefeld: Universität Bielefeld; 2019.If anthropomorphic robots are to assist people with activities of daily living, they must be able to handle all kinds of everyday objects, including highly deformable ones such as garments. The present thesis begins with a detailed problem analysis of robotic interaction with and perception of clothes. We show that handling items of clothing is very challenging due to their complex dynamics and the vast number of degrees of freedom. As a result of our analysis, we obtain a topological, geometric, and functional description of garments that supports the development of reduced object and task representations. One of the key findings is that the boundary components, which typically correspond with the openings, characterize garments well, both in terms of their topology and their inherent purpose, namely dressing. We present a polygon-based and an interactive method for identifying boundary components using RGB-D vision with application to grasping. Moreover, we propose Active
Boundary Component Models (ABCMs), a constraint-based framework for tracking garment openings with point clouds. It is often difficult to maintain an accurate representation of the objects involved in contact-rich interaction tasks such as dressing assistance. Therefore, our policy optimization approach to putting a knit cap on a styrofoam head avoids modeling the details of the garment and its deformations. The experimental results suggest that a heuristic performance measure that takes into account the amount of contact established between the two objects is suitable for the task
Robotics 2010
Without a doubt, robotics has made an incredible progress over the last decades. The vision of developing, designing and creating technical systems that help humans to achieve hard and complex tasks, has intelligently led to an incredible variety of solutions. There are barely technical fields that could exhibit more interdisciplinary interconnections like robotics. This fact is generated by highly complex challenges imposed by robotic systems, especially the requirement on intelligent and autonomous operation. This book tries to give an insight into the evolutionary process that takes place in robotics. It provides articles covering a wide range of this exciting area. The progress of technical challenges and concepts may illuminate the relationship between developments that seem to be completely different at first sight. The robotics remains an exciting scientific and engineering field. The community looks optimistically ahead and also looks forward for the future challenges and new development
Visual Dexterity: In-hand Dexterous Manipulation from Depth
In-hand object reorientation is necessary for performing many dexterous
manipulation tasks, such as tool use in unstructured environments that remain
beyond the reach of current robots. Prior works built reorientation systems
that assume one or many of the following specific circumstances: reorienting
only specific objects with simple shapes, limited range of reorientation, slow
or quasistatic manipulation, the need for specialized and costly sensor suites,
simulation-only results, and other constraints which make the system infeasible
for real-world deployment. We overcome these limitations and present a general
object reorientation controller that is trained using reinforcement learning in
simulation and evaluated in the real world. Our system uses readings from a
single commodity depth camera to dynamically reorient complex objects by any
amount in real time. The controller generalizes to novel objects not used
during training. It is successful in the most challenging test: the ability to
reorient objects in the air held by a downward-facing hand that must counteract
gravity during reorientation. The results demonstrate that the policy transfer
from simulation to the real world can be accomplished even for dynamic and
contact-rich tasks. Lastly, our hardware only uses open-source components that
cost less than five thousand dollars. Such construction makes it possible to
replicate the work and democratize future research in dexterous manipulation.
Videos are available at:
https://taochenshh.github.io/projects/visual-dexterity
Advanced Knowledge Application in Practice
The integration and interdependency of the world economy leads towards the creation of a global market that offers more opportunities, but is also more complex and competitive than ever before. Therefore widespread research activity is necessary if one is to remain successful on the market. This book is the result of research and development activities from a number of researchers worldwide, covering concrete fields of research