Design of Matlab/Opensim Robust Controller of an Exoskeleton for Disuse Muscular Atrophy Rehabilitation of A Human Arm

Abstract

The mean goal of this paper is to describe the design and control approach of an exoskeleton for rehabilitation of the disuse muscular atrophy of a human arm. This work includes three main parts: Firstly, the exoskeleton model wes design by Autodesk Inventor 3D software. Secondly, the dynamic simulation of the designed exoskeleton model attached to the human arm was performed using OpenSim software and its Matlab API extension, and finally a robust control law was simulated in order to ensure tracking of the rehabilitation trajectories applied by the exoskeleton to the human arm. OpenSim software makes it possible to simulate movements with musculoskeletal models, namely, the human arm. Rehabilitation in this case consists in a precise exercises given by the therapist. In our case, it is the repetitive trajectories given to the exoskeleton that must be controlled. A sliding mode controller was used since it is a robust control and ensures the best solutions to uncertainty issues. Through simulation, we tested some rehabilitation reference trajectories for the elbow and shoulder. The controller ensures high performances in terms of trajectory tracking in the presence of initial errors and also in the presence of model parameter errors. That showed the effectiveness of the exoskeleton control.