A Control Strategy for a Lower Limb Exoskeleton with a Toe Joint

摘要

In this paper a lower limb exoskeleton with a toe joint is studied. A mathematical model of the exoskeleton is presented, and the equations of motion are given. The exoskeleton is controlled with a feedback controller. The control system attempts to move the center of mass of the exoskeleton along the desired trajectory. To find the joint space trajectory that allows to perform the desired motion a numerical optimization-based iterative algorithm for solving inverse kinematics is given. The algorithm allows to engage and disengage the toe joint, based on how close the mechanism is to a singular position. That gives us an automatic human-like toe joint engagement, that can be controlled though certain parameters, which is discussed in the paper. The results of the numerical simulation of the exoskeleton motion are presented.