Design and Evaluation of Finger-operated Teleimpedance Interface Enabling Simultaneous Control of 3D Aspects of Stiffness Ellipsoid

In this paper, we present a design and evaluation of a novel finger-operated teleimpedance interface used to command stiffness ellipsoids to the remote robot. The proposed interface provides a practical alternative to the state-of-the-art teleimpedance interfaces based on physiological signals that can be impractical in daily use. On the other hand, as opposed to existing practical interfaces that lack in terms of controlled degrees of freedom, the proposed interface enables control of 3D aspects of the ellipsoid. The remote robot stiffness ellipsoid is controlled with a single hand using the thumb, index, and middle fingers to operate two scroll wheels, a joystick, and a force sensor. These combinations of inputs can be mapped to control different aspects of the stiffness ellipsoid, i.e., orientation and shape/size. To investigate different modes of input mapping, we perform a human factors experiment to evaluate the performance and user acceptance of the proposed interface modes. The results of the experiments indicate that the participants can successfully operate the interface to complete 3D stiffness configuration alignment tasks in different modes. To further demonstrate the functionality of the proposed teleimpedance interface, we performed an additional experiment utilising a Force Dimension Sigma7 haptic device to control the motion of a KUKA LBR iiwa robotic arm while performing a complex physical interaction task.