Shared Grasping: a Combination of Telepresence and Grasp Planning

''Shared Grasping'' describes a new approach to shared autonomy for grasping and manipulation tasks to be used in a telepresence system. It is realized with two assistance functionalities, which simplify the grasping, and a user interface, which merges haptic feedback and visual assistance. User studies confirm a reduction in operator workload and an increase in task performance while maintaining a high immersion of the operator into the remote environment when using the assistance functions

Shared Grasping: a Combination of Telepresence and Grasp Planning

''Shared Grasping'' describes a new approach to shared autonomy for grasping and manipulation tasks to be used in a telepresence system. It is realized with two assistance functionalities, which simplify the grasping, and a user interface, which merges haptic feedback and visual assistance. User studies confirm a reduction in operator workload and an increase in task performance while maintaining a high immersion of the operator into the remote environment when using the assistance functions

Erweiterung eines passivitätsbasierten Reglers für haptisches Rendering

In dieser Arbeit wird der von J.-H. Ryu, Y. Kim und B. Hannaford 2004 vorgestellte Time Domain Passivity Controller für ein haptisches System mit Totzeiten und sieben aktuierten Gelenken sowie sechs kartesischen Freiheitsgraden erweitert. Dazu wird zum einen die Totzeit im Passivity Observer berücksichtigt und die Energiebeobachtung durch verschiedene Schätzmethoden verbessert, zum anderen die Berechnung der Kraft des Passivity Controllers durch die Verallgemeinerung der Dämpfung auf mehrere Freiheitsgrade angepasst. Sowohl für den Fall mit einem Freiheitsgrad sowie für den mit mehreren Freiheitsgraden wird zusätzlich eine Begrenzung der Dämpfung des Passivity Controllers vorgestellt, durch die Instabilität des Systems verhindert wird. Das Konzept wird durch Simulation verifiziert und wird mit verschiedenen Implementierungen des erweiterten Reglers (gelenkbasiert und kartesisch) an den Leichtbaurobotern des Deutschen Zentrums für Luft- und Raumfahrt angewandt. Die Implementierungen werden anhand von Experimentergebnissen miteinander verglichen und bestätigen das Konzept des erweiterten Time Domain Passivity Controllers

Constraint-based Sample Propagation for Improved State Estimation in Robotic Assembly

In fast changing assembly scenarios, it is required to adapt the task execution to the current state of the setup without extensive calibration routines. Therefore, it is important to estimate the geometric uncertainties and contact states during the assembly execution. We use a sequential Monte Carlo (SMC) method to track the relative poses between workpieces during a robotic assembly based on joint torque and position measurements only. In contrast to existing approaches, we focus on assembly tasks where the workpiece is not fixed in the workcell, but can, for example, slide on a table surface. We propose a new constraint-based propagation model for the SMC approach: a compensation motion for the samples dependent on the violation of contact constraints is derived. This allows us to track the motion of the workpieces in cases where a common random diffusion model fails. The method is evaluated with experiments using an assembly scenario with two KUKA LBR iiwa robot arms and shows accurate tracking performance

A Platform for Bimanual Virtual Assembly Training with Haptic Feedback in Large Multi-Object Environments

We present a virtual reality platform which addresses and integrates some of the currently challenging research topics in the field of virtual assembly: realistic and practical scenarios with several complex geometries, bimanual six-DoF haptic interaction for hands and arms, and intuitive navigation in large workspaces. We put an especial focus on our collision computation framework, which is able to display stiff and stable forces in 1 kHz using a combination of penalty- and constraint-based haptic rendering methods. Interaction with multiple arbitrary geometries is supported in realtime simulations, as well as several interfaces, allowing for collaborative training experiences. Performance results for an exemplary car assembly sequence which show the readiness of the system are provided