Design and Analysis of a 2-DoF Exoskeleton Utilizing Force Sensors for Adaptive Trajectory Tracking

Abstract

This study develops a Two-Degree-of-Freedom (2-DoF) lower-limb exoskeleton for rehabilitation applications. The system combines trajectory tracking control with a force-feedback control system to improve human–exoskeleton interaction during rehabilitation movements. Real-time force information is incorporated into the control framework to adjust joint motion according to the interaction conditions between the user and the exoskeleton. A kinematic and dynamic model of the system is established and evaluated through MATLAB simulation. Experimental evaluations are conducted using both single- and dual-force sensor configurations. The results show that the dual-force sensor configuration provides enhanced motion stability and lower oscillatory behavior compared with the single-force sensor configuration. The integration of trajectory tracking control and force-feedback control contributes to smoother movement, enhanced stability, and better rehabilitation performance. These results support the application of force-based interaction control in lower-limb rehabilitation exoskeletons.