Design and modeling of a joystick control scheme for an upper limb powered exoskeleton

This paper presents a control scheme for a 5 DOFs upper limb powered exoskeleton. A joystick-based interface was chosen in order to receive the desired cartesian position and relative orientation of the end effector from the user. The control scheme verifies the belonging of the commanded position to the exoskeleton workspace before proceeding with the inverse kinematic optimization. As assistive device, the exoskeleton has to operate according to user’s intention. Therefore, control scheme’s capacity to track the desired cartesian trajectory is investigated. Robot redundancy is here exploited in order to minimize joint torques and avoiding singularities.