An Impedance Control of Human Ankle Joint Using Functional Electrical Stimulation

During human gait, the mechanical impedances of lower limb joints are modulated to achieve better stabilization and energy efficiency. Therefore, modulating impedance is a promising method to assist the patients with impaired gait. In this paper, we have attempted to implement the impedance modulation of ankle joint by using an impedance control scheme based on functional electrical stimulation. The control scheme, position-based impedance control, contains desired impedance model and a robust inner loop position controller using time delay estimation. The feasibility of the proposed impedance modulation using impedance control was shown through an experiment.