Active-external enveloping grasps: dynamical-balance based motion analysis

Enveloping grasp systems not in static equilibrium result in dynamical motion. In this article, we develop a method based on dynamical-balance to solve motion analysis problem for an active-external grasp, that is to determine contact forces and accelerations consistent with the dynamics and friction law for a given torque-wrench pair. Since the method is analytic in nature, it may give the chance for better efficiency and more direct insight than a relevant linear complementarity formulation, although the solutions are the same. The method is verified using two examples: one is a simple grasp system with one frictional contact, and the other is a relatively general one with all frictionless contacts.