Dynamical estimation of human arm stiffness in context of sEMG based teleoperation

Abstract

Impedance based teleoperation (teleimpedance) is believed to be safer and more intuitive than conventional techniques. And a relationship between human arm stiffness and its surface EMG signal (sEMG) is expected. Therefore, the ultimate goal of the project aims at building up a map between sEMG and human arm stiffness and apply it to teleimpedance. During the course of the project, a methodology that measures dynamic human arm stiffness has been invented using a specialized 2D manipulandum. A series of experiments have been conducted with EMG data recorded by a novel sensor with short overall duration (under 20min) while having abundance of data (over 3000 stiffness-EMG pairs). The methodology is able to give estimations of full dynamics of human arm, including endpoint stiffness, mass, and damping. The estimated mass has good quality and great correspondence with experimental facts; while the dynamic stiffness shows both variance and correspondence to static stiffness, theoretical support is lacking under the setupped situation. A preliminary investigation has shown EMG linear regression of estimated stiffness is insufficient and more complicated models need to be applied.