Section: New Results

Modeling and simulation of a human hand

Participants : Daniel Simon, Ahmed Farek.

The AGILIS stimulation system is intended to generate grasping action on some objects such as balls and cans. A high-fidelity hand model and associated simulation software was developed to anticipate real experiments and help for the system identification and tuning [30]. The hand model uses 23 degrees of freedom for the wrist and fingers. 28 muscles are considered, including the 12 muscles which are expected to be activated using electrical stimulation of the median and radial nerves. Others are also considered in the model as, even if not stimulated, they contribute to the hand and fingers movements through passive forces when extended. Several actuation models are investigated to allow for the identification of muscles-to-movements relations.

The active forces provided by the stimulated muscles are computed thanks to the original model developed over the past years by the team, where the inputs are currents injected to muscles or nerves. The fingers are assumed to interact with the grasped object through elastic contacts and limited friction.

Figure 11. Simulation of a stimulated hand grasping a can