Adaptive CPG-Based Impedance Control for Assistive Lower Limb Exoskeleton

Abstract

Adaptation to user's impedance properties has been viewed imperative in developing assistive exoskeletons. However, most exoskeletons are still rather controlled with predefined joint trajectories. Inspired by the success in locomotion control for humanoid robots using central pattern generator (CPG) and impedance control for human-robot interaction, an impedance control based on CPG that can adapt to human's impedance properties is presented in this work. The proposed method is validated by a simulation in MATLAB/Simulink, integrating a 6-DOF lower limb exoskeleton model with a musculoskeletal human model. Simulation results indicate that the lower limb exoskeleton, incorporating the proposed adaptive CPG-based impedance controller, can effectively assist human walking.