A Method for Hand Kinematics Designers 7 Billion Perfect Hands

Abstract

In the past decade the design of kinematic models for hands has been addressed using several different approaches such as numerical optimization or direct measurement of human hands. However, once the mechanical and structural design constraints are included, no existing kinematic model of the hand fits the needs of the DLR Hand Arm System. The diversity of human hands reveals that the functional aspects are more important than the kinematics itself. In order to develop a suitable model for the hand arm system a more empirical method was developed. Based on an basic hand skeleton, that incorporates the structural constraints, incremental variations are performed to improve the parameters to fit the functional needs of the hand. The tests are derived from a set of common grasps as well as some tests performed by surgeons. To be able to rapidly appreciate the results simple cardboard prototypes are constructed. The resulting kinematics revealed to be a promising and suitable hand kinematics for the DLR Hand Arm System. The design is realized in hardware.