Dimensional Synthesis of One-Jointed Multi-fingered Hands

Wristed, multi-fingered hands can be designed for specific tasks, leading to an optimized performance and simplicity. In this work we present the design of the simplest family of multi-fingered hands, with one revolute joint at the wrist and a set of fingers attached to the palm with a single revolute joint each. It is shown that hands with two to five fingers can be designed for meaningful tasks, and that two arbitrary positions can be defined at most for these hands, yielding a good tool for pick-and-place, or grasp-and-release, tasks. For each of those possible designs, dimensional synthesis is performed and an algebraic solution is derived. It is proved that two solutions exist for the general case of this family of hands. Coupled actuation for the grasp-and-release task can be easily implemented for these hands, to create an underactuated design able to be driven with a single actuator. Some examples are presented.