Abstract

Mapping the operator’s six-DoF hand pose to the follower system’s end-effector with inverse kinematics is a common approach in pose-tracking teleoperation. However, this approach suffers from non-intuitive orientation motion mapping caused by follower-side singularities, especially when the follower system follows the Pieper kinematics structure. In this work, we propose two singularity-avoiding motion mapping strategies to resolve this problem. One approach locks one DoF on the follower side to avoid wrist singularity, while the other approach appends additional joints but preserves all six DoFs of the follower’s end-effector. Additionally, we introduce the concept of an operational Jacobian to formally analyze the smoothness of follower joint motions under pose-tracking teleoperation. Using global-local interface as the experiment platform, we demonstrate the significant improvements in control dexterity and robustness against singularities compared to conventional motion mapping based in inverse kinematics.

Publications

J. Zhou, B. Liang, J. Huang, H. Zhang, I. Zhang, Y. Wang, P. Abbeel, & M. Tomizuka. “Singularity-Avoidant Motion Mappings for Pose-Tracking Teleoperation with Operational Jacobian Analysis”. Under Review for IEEE/ASME Transaction on Mechatronics