TSA-BRAG: A Twisted String Actuator-powered Biomimetic Robotic Assistive Glove
Thulani Tsabedze, E. Frederick Hartman, Edwin Abrego, Cianan Brennan, Jun Zhang
Abstract
It is highly desirable but challenging to create assistive robot systems and devices that are inherently safe, compact, and can produce sufficient power and force. Twisted string actuators (TSAs) are appealing for assistive robotic applications because they are compliant, energy-efficient, capable of producing large translational force, and exhibit high power density. This paper presents the first performance comparison of motor-spool and TSA configurations, and shows that TSAs generate 5 times more force output than that of the motor-spool configuration. TSAs are then employed to power a biomimetic robotic assistive glove (BRAG). The design and control of the developed TSA-BRAG are detailed. Preliminary experiments show that the TSA-BRAG can be used to effectively pick up everyday objects using an unpowered three-dimensionally printed robotic hand and an able-bodied human hand. Being compliant, compact, and powerful, the proposed TSA-BRAG shows strong potential in human augmentation and rehabilitation.