Investigation of friction characteristics of a tendon driven wearable robotic hand

Wearable robots can assist people with disabilities to perform their daily tasks. However, the size, weight and wearability are important factors in the design because it is worn by the person controlling it. Various disabilities can be assisted with wearable robot technology, from the lower to upper body. The hand is an important part of the body for the disabled to perform their daily tasks. However, compared to the arms or legs, the degree of freedom is much higher, which makes it difficult to fabricate a compact wearable robot. We propose a frameless structure and modified differential mechanism to make the wearable robot compact. For the evaluation and control, it is necessary to analyze the friction force because the mechanism we proposed delivers power through more tube than the previous tendon tube transmission. Different from the previous friction model, we consider the friction at the edge of tube ends. This paper contains the design concept of the developed wearable robotic hand and its friction characteristics.