The impressive manipulation capabilities of the human hand are undoubtedly related to the thumb opposition. Such a versatility is highly desirable in the context of humanoid robots, in particular when performing object manipulation. In the present case, a robotic hand with size, forces, velocity, and shape comparable to the human one, is envisioned. Unlike most robotic designs — where the fingers are modular and the thumb is simply a finger placed in opposition — the thumb benefits from an intensive functional analysis. This paper details the design method of the thumb of the Awiwi hand, the hand of the Integrated Hand Arm System project of DLR. First, several guidelines are presented that are fused and, with the help of a novel optimization method, lead to the final design. Finally, the design is evaluated by the means of biomedical tests on the realized hardware.
Proprioceptive shape signatures for object manipulation and recognition purposes in a robotic hand
