Underactuated Three-Finger Robot Hand with Human-Like Flexion

Numerous studies have been conducted on three-finger robot hands, which are widely used in industries. These studies led to the development of motorized prosthetic hands for amputees. Although many developers have focused on the functionality of motorized prosthetic hands, prosthetic users place more importance on the human-like motion of the device owing to social implications. Therefore, this study aims to achieve human-like flexion of a three-finger robot hand. Each finger contains three phalanges joined by pivots and torsional return springs. A tendon wire runs through guide pins inside the phalanges up to the linear actuator located in the forearm. When the tendon wire is pulled, the finger is flexed. The return springs are optimally selected based on ADAMS simulations and kinesiology of the human hand. The selection is then verified by experiments