%0 Journal Article
%T A variable admittance control strategy for stable physical human¨Crobot interaction
%A Cesare Fantuzzi
%A Chiara Talignani Landi
%A Cristian Secchi
%A Federica Ferraguti
%A Lorenzo Sabattini
%A Marcello Bonf¨¨
%J The International Journal of Robotics Research
%@ 1741-3176
%D 2019
%R 10.1177/0278364919840415
%X Admittance control allows a desired dynamic behavior to be reproduced on a non-backdrivable manipulator and it has been widely used for interaction control and, in particular, for human¨Crobot collaboration. Nevertheless, stability problems arise when the environment (e.g. the human) the robot is interacting with becomes too stiff. In this paper, we investigate the stability issues related to a change of stiffness of the human arm during the interaction with an admittance-controlled robot. We propose a novel method for detecting the rise of instability and a passivity-preserving strategy for restoring a stable behavior. The results of the paper are validated on two robotic setups and with 50 users performing two tasks that emulate industrial operations
%K physical human¨Crobot interaction
%K cooperative manipulators
%K admittance control
%K human-in-the-loop
%U https://journals.sagepub.com/doi/full/10.1177/0278364919840415