Design of a tendon-driven force-controlled dexterous hand

Designing a dexterous robot hand that is flexible, force controllable and capable of grasping objects of various shapes and materials is very important in robot design. The difficulties lie in the flexible structure and the adaptive grasping strategies to handle different shapes of objects, and how to avoid contact damages to the target object. In this paper, a tendon-driven force-controlled hand is proposed, which adopts the design of differential gear and tendon arrangement similar to human fingers. This allows it to have higher degrees of freedom than the general underactuated gripper, so it has better adaptability and flexibility. Firstly, the mechanical design of the robot hand is introduced. Then, the kinematical model of the robot hand is analyzed. The dynamic model is established which could be used evaluate the performance of the robot. An admittance control scheme is adopted to grasp soft fragile objects. Finally, simulation and experiments are carried out. Experiments show that the proposed tendon-driven force-controlled dexterous hand is able to grasp objects with different shapes and materials and is capable of grasping soft fragile objects without crushing.