Abstract-The framework of dynamic movement primitives (DMPs) contains many favorable properties for the execution of robotic trajectories, such as indirect dependence on time, response to perturbations, and the ability to easily modulate the given trajectories, but the framework in its original form remains constrained to the kinematic aspect of the movement. In this paper, we bridge the gap to dynamic behavior by extending the framework with force/torque feedback. We propose and evaluate a modulation approach that allows interaction with objects and the environment. Through the proposed coupling of originally independent robotic trajectories, the approach also enables the execution of bimanual and tightly coupled cooperative tasks. We apply an iterative learning control algorithm to learn a coupling term, which is applied to the original trajectory in a feed-forward fashion and, thus, This paper has supplementary downloadable material available at http:// ieeexplore.ieee.org, provided by the author. The video shows the application of the proposed algorithm in four distinct tasks. The first part of the video shows the applicability of the algorithm for modulating a given trajectory in order to achieve a desired contact force with the environment. In ten epochs, the algorithm is first applied to achieve the desired contact force 0 N, i.e., to approach and not touch the object, and later 15 N. The second experiment shows the performance of the approach when coupling two trajectories in a bimanual task, where the force along the manipulated object is minimized. In the third part, we show the performance of the approach for minimizing the force along the object when one or both of the arms in a bimanual task have to avoid obstacles. The final, fourth part, shows a bimanual human-robot cooperative task, where the robots and the person have to put a lid with a tight fit on a box. The box is moved and the proposed algorithm is used to adapt the trajectories of the robots with respect to the forces exerted by the person and from contact with the box, so that by the final, eighth epoch, the robots do not need any interference to place the lid on the box. properties, which is demonstrated with temporal modulation and in a two-agent obstacle avoidance task. Index Terms-Bimanual operation, cooperative task, dynamic movement primitives (DMPs), interaction with environment.
REF extends the DMP framework by adding a modulation term that allows interaction with objects and the environment.
Coupling Movement Primitives: Interaction With the Environment and Bimanual Tasks
IEEE Transactions on Robotics
IEEE Transactions on Robotics
Computer Science