Merging Position and Orientation Motion Primitives

In this paper, we focus on generating complex robotic trajectories by merging sequential motion primitives. A robotic trajectory is a time series of positions and orientations ending at a desired target. Hence, we first discuss the generation of converging pose trajectories via dynamical systems, providing a rigorous stability analysis. Then, we present approaches to merge motion primitives which represent both the position and the orientation part of the motion. Developed approaches preserve the shape of each learned movement and allow for continuous transitions among succeeding motion primitives. Presented methodologies are theoretically described and experimentally evaluated, showing that it is possible to generate a smooth pose trajectory out of multiple motion primitives

Detection of Collaboration and Collision Events during Contact Task Execution

This work introduces a contact event pipeline to distinguish task-contact from Human-Robot interaction and collision during task execution. The increasing need for close proximity physical human-robot interaction (pHRI) in the private, health and industrial sector demands for new safety solutions. One of the most important issues regarding safe collaboration is the robust recognition and classification of contacts between human and robot. A solution is designed, that enables simple task teaching and accurate contact monitoring during task execution. Besides an external force and torque sensor, only proprioceptive data is used for the contact evaluation. An approach based on demonstrated task knowledge and the offset resulting from human interaction is designed to distinguish contact events from normal execution by a contact event detector. A contact type classifier implemented as Support Vector Machine is trained with the identified events. The system is set up to quickly identify contact incidents and enable appropriate robot reactions. An offline evaluation is conducted with data recorded from intended and unintended contacts as well as examples of task-contacts like object manipulation and environmental interactions. The system's performance and its high responsiveness are evaluated in different experiments including a real world task