TY - JOUR T1 - A Spherical Active Joint for Humanoids and Humans JF - IEEE Robotics and Automation Letters Y1 - 2019 A1 - S. Mghames A1 - M. G. Catalano A1 - A. Bicchi A1 - G. Grioli VL - Volume: 4 , Issue: 2 , April 2019 ER - TY - CONF T1 - Design, control and validation of the variable stiffness exoskeleton FLExo T2 - International Conference on Rehabilitation Robotics (ICORR) Y1 - 2017 A1 - S. Mghames A1 - M. Laghi A1 - C. Della Santina A1 - M. Garabini A1 - M. G. Catalano A1 - G. Grioli A1 - A. Bicchi KW - Robotics AB -

In this paper we present the design of a one degree of freedom assistive platform to augment the strength of upper limbs. The core element is a variable stiffness actuator, closely reproducing the behavior of a pair of antagonistic muscles. The novelty introduced by this device is the analogy of its control parameters with those of the human muscle system, the threshold lengths. The analogy can be obtained from a proper tuning of the mechanical system parameters. Based on this, the idea is to control inputs by directly mapping the estimation of the muscle activations, e.g. via ElectroMyoGraphic(EMG) sensors, on the exoskeleton. The control policy resulting from this mapping acts in feedforward in a way to exploit the muscle-like dynamics of the mechanical device. Thanks to the particular structure of the actuator, the exoskeleton joint stiffness naturally results from that mapping. The platform as well as the novel control idea have been experimentally validated and the results show a substantial reduction of the subject muscle effort.

JF - International Conference on Rehabilitation Robotics (ICORR) PB - IEEE CY - London, UK, 17-20 July 2017 UR - http://ieeexplore.ieee.org/document/8009304/ ER -