A semi-direct drive hand exoskeleton using ultrasonic motor

In this paper, we address an exoskeletal type haptic device which helps the human actively feel the sense of touch in palmar and dorsal directions. The device consisting of two finger-like parts taken by thumb and index finger, is designed in modular type to expand easily for five fingers. The proposed device is semi-directly driven by ultrasonic motors which have high power-to-weight ratio, and it provides haptic feedback to each joint of fingers. Methods for measuring the angular displacements and torques of the fingers are proposed and basic experiments are performed to verify the effectiveness of the system.