Mobility of bodies in contact. I. A new 2/sup nd/ order mobility index for multiple-finger grasps

Using a configuration-space approach, this paper develops a coordinate invariant 2/sup nd/ order mobility index for a body, B, in frictionless contact with finger bodies A/sub 1/,...,A/sub k/. The index captures the inherent mobility of B in an equilibrium grasp due to 2/sup nd/ order, or surface curvature, effects. It differentiates between grasps which are deemed equivalent by the classical 1/sup st/ order theories, but are physically different. In a companion paper we discuss applications and provide physical justification for using 2/sup nd/ order immobility effects.<
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