Development of a 3DOF mobile exoskeleton robot for human upper-limb motion assist

In order to assist physically disabled, injured, and/or elderly persons, we have been developing exoskeleton robots for assisting upper-limb motion, since upper-limb motion is involved in a lot of activities of everyday life. This paper proposes a mechanism and control method of a mobile exoskeleton robot for 3DOF upper-limb motion assist (shoulder vertical and horizontal flexion/extension, and elbow flexion/extension motion assist). The exoskeleton robot is mainly controlled by the skin surface electromyogram (EMG) signals, since EMG signals of muscles directly reflect how the user intends to move. The force vector at the end-effector is taken into account to generate the natural and smooth hand trajectory of the user in the proposed control method. An obstacle avoidance algorithm is applied to prevent accidental collision between the user’s upper-limb and the robot frame. The experiment was performed to evaluate the effectiveness of the proposed exoskeleton robot.