Task-Invariant Control of a Knee-Ankle Exoskeleton over the Primary Activities of Daily Life

A single control law provides biomimetic assistance torques over the primary activities of daily life (level walking, ramp ascent/descent, stair ascent/descent, and sit-to-stand) without any intent or environment detection. The control law was designed by a data-driven optimization of energy-shaping basis functions. Activation of dominant muscles is compared between two versions of the controller and no exoskeleton whatsoever. Supplemental multimedia for the article: J. Lin, N. Divekar, G. Thomas, and R. Gregg, “Optimally Biomimetic Passivity-Based Control of a Lower-Limb Exoskeleton over the Primary Activities of Daily Life,” IEEE Open Journal of Control Systems, 2022. This work was supported by the National Science Foundation and the National Institutes of Health.