Reference-model-based control including human torque estimation for cable-driven rehabilitation system

Abstract

This paper presents a reference-model-based control strategy for human-interactive rehabilitation devices designed to ensure robust assistance during movement. The proposed approach combines feedforward and feedback actions to control the nonlinear system along physiotherapist-defined trajectories. The human torque, which represents the patient’s contribution to movement, is estimated in real-time using a Proportional-Integral Observer. This real-time estimation allows the system to adjust the level of assistance according to the user’s capabilities. Experimental validation in a prototype demonstrates the effectiveness of the proposed approach.