Feasibility study of a slack enabling actuator for actuating tendon-driven soft wearable robot without pretension

Abstract

A soft wearable robot with a tendon drive is a promising technology that enables a wearable robot to be compact and lightweight. A soft tendon routing system was previously proposed to apply a tendon drive to a soft wearable robot. In this study, a slack enabling mechanism was proposed to increase the efficiency and guarantee the safety of the soft tendon routing system. The proposed mechanism eliminates the pre-tension of the tendons and minimizes the friction induced by the pre-tension, which causes inefficiency and a lack of safety. Furthermore, the slack enabling mechanism mechanically prevents the derailing of the tendon from the spool. In order to verify the benefits of the proposed mechanism, a prototype was built and tested on the Exo-Glove, which is a soft wearable robot for the hand. The experiment results showed that the prototype could completely remove the pre-tension, whichproposed to apply a tendon drive to a soft wearable robot. In this study, a slack enabling mechanism was proposed to increase the efficiency and guarantee the safety of the soft tendon routing system. The proposed mechanism eliminates the pre-tension of the tendons and minimizes the friction induced by the pre-tension, which causes inefficiency and a lack of safety. Furthermore, the slack enabling mechanism mechanically prevents the derailing of the tendon from the spool. In order to verify the benefits of the proposed mechanism, a prototype was built and tested on the Exo-Glove, which is a soft wearable robot for the hand. The experiment results showed that the prototype could completely remove the pre-tension, which allowed the Exo-Glove to function well with the prototype.