Design of tendon mechanism for soft wearable robotic hand and its fuzzy control using electromyogram sensor

Abstract

This study proposes a wearable robotic hand using an improved tendon mechanism enhanced compared to the existing link one with heavy and hard-to-ware. The enhanced wearable robot hand is controlled using the electromyogram (EMG) sensor. In previous tendon mechanism of wearable robotic hand, it only implemented the flexor digitorum profundus (FDP) tendon. Therefore, the fingertip is flexed much more, which means that the radius of curvature is large, so the motion of gripping an object became unstable. Prototype of the first proposed tendon-driven wearable robotic hand is implemented to both FDP and flexor digitorum superficialis tendon, so that the middle phalanx can flex with the distal phalanx. This leads the motion of gripping objects become stable. However, it is difficult to move the distal phalanx and middle phalanx together to grab the object completely. The second improved tendon mechanism of wearable robotic hand is implemented to only FDP, but it sets different friction force to each guide; thus, it can grip the object completely. The EMG sensor is used to detect the motion of the finger, and the fuzzy controller is used to control the finger of the wearable robotic hand according to the amount of muscle used.