Force Observer for an Upper Limb Rehabilitation Robotic Device using Iterative Learning Control

This paper focuses on detecting the forces exerted by stroke patients in the repetitive exercises using the rehabilitation robotic system: EMU, without using any external force sensor. As the model of such a system is hard to identify precisely, a simple feedback-based iterative learning control algorithm is proposed to identify such forces. The convergence analysis of such force estimators is provided in this paper. The simulation and experimental results illustrates the effectiveness of the proposed force observers.