Influence of fingertip and object shape on the manipulation ability of underactuated hands

This paper presents a kinetostatic framework to analyze the grasping and in-hand object manipulation abilities of two-finger underactuated hands. The framework includes a procedure to compute the Grasp Matrix and the Hand Jacobian for objects and fingertips of arbitrary shape considering rolling contacts without slipping. The usefulness of the proposed approach is illustrated in a case study of a pair of underactuated fingers driven by a tendon-pulley differential transmission mechanism and capable of performing in-hand object manipulation. The manipulability region for different object and fingertip shapes is computed and the results are discussed.