On computation of grasping forces in dynamic manipulation using a three-fingered grasp

Computation of the grasping force between the fingers and object is one of the main requirements for object manipulation. Traditionally the upper bound on the magnitudes of the grasping forces have been determined based on some local static constraints using optimization techniques. These methods usually do not incorporate the actual properties of the motion trajectories and external forces which can act on the grasped object. In addition, in most cases, various subproblems of the general grasping have been considered and a comprehensive method for modelling and analysis of such a system has not been addressed in the literature. This paper presents a general, efficient and elegant frame-work for computing the grasping forces in dynamics manipulation of objects. The presented frame-work is general and does not rely on any special relationships between the configuration of the end-effector and properties of the grasped object. The method takes into account the external task forces and the inertia force and then adaptively determines the required grasping forces as a function of the local contact friction properties. It utilizes the screw geometry, Lie algebra, inner product spaces and information regarding the grasp geometry and its motion trajectories. The method of the paper is also demonstrated through an example. (C) 1997 Elsevier Science Ltd.