The invention relates to a finger device of a unilateral-
coupling and self-adaption composite type underactuated
robot, belonging to the technical field of
humanoid robot hands. The finger device comprises a base, a motor, a speed
reducer, a near joint shaft, a
middle finger section, a far joint shaft, a
tail-end finger section, a unilateral-
coupling transmission mechanism, an underactuated transmission mechanism and a spring piece. In the device, a single
tendon rope coupling transmission mechanism, a self-adaption transmission mechanism and the spring piece are adopted to comprehensively realize a composite underactuated capture mode formed by combining coupling capture and self-adaption capture; as the single
tendon rope coupling transmission mechanism does not interfere the self-adaption capture process, the decoupling mode is very natural, so that the internal
power consumption in the capture process is reduced to the maximum extent and the transmission efficiency is reduced; the capture process of the device is humanized and the finger device has self-adaption capability to the size of the captured object; the finger device has a simple structure, low cost and little
energy consumption, is easy to control, has similar appearance and action as the hands of a
human body and is suitable for the
humanoid robot hands.