Modeling and Control of an Upper-Body Exoskeleton

In this paper we propose an upper body exoskeleton to augment a soldier´s ability to maneuver and fire a heavy weapon. After describing the initial design concept, we model the system dynamics both using Lagrange´s method and the SimMechanics software package. We derive a controller for our upper body exoskeleton, loosely inspired by the novel approach used on the Berkeley lower body exoskeleton (BLEEX). The approach is to combine the computed torque method, along with a nearly marginally stable linear feedback law. The resulting controller can track the wearer´s movement with without the need to measure muscular activation levels. We simulation results for the controller with a human torque input. The contributions, while modest, are an important first step in evaluating the feasibility of this approach for an upper body exoskeleton.