Design and control of a hydraulic-actuated leg exoskeleton for load-carrying augmentation

Abstract

For the research on control method of leg exoskeleton for carrying payload, a leg exoskeleton prototype called ELEBOT (ECUST Leg Exoskeleton roBOT) has been built. To increase the load-carrying ability of exoskeleton, pseudo-anthropomorphic mechanical structure, a kind of efficient, low-flow pump-valve hybrid controlled hydraulic actuator, custom sensing shoes and other electrical components for control have been developed. A knee torque estimate algorithm based on GRF (ground reaction force) was applied to ELEBOT via a hydraulic direct force feedback PD controller. Experiments indicated ELEBOT could support itself and 30 kg additional payload with above control method when it was walking at a speed up to 3.2 km/h while following the operator's maneuvers. These results indicate the control method discussed in this work is valid. © 2010 Springer-Verlag.