Development of the Ultrasonic Motor-Powered Assisted Suit System

This paper reports the development of a power-assisted suit system actuated by ultrasonic motors. The proposed assisted suit is designed to support a caretaker performing nursing care tasks. The structure of the assisted suit has been designed to cover the caretaker´s motions as much as possible, and the suit is equipped with ultrasonic motors mounted in areas close to the joint rotation axis of the elbow, shoulder, waist, and knee. The suit frame is designed as an exoskeleton structure that can protect the wearer from bearing the suit´s weight because the foot part contacts the ground. A Phi60 double sandwich-type motors are used for the upper body part of the assisted suit. The torque of the double sandwich-type motor is about 3.8 times compared to the torque of the single sandwich-type motor. From the above results, the double sandwich-type motor is less space-saving but has high torque efficiency, and is therefore suitable as the actuator for the upper part of the assisted suit.