Controlled slip: an approach within planning dexterous manipulation in three-fingered grasp

Manipulation of objects by multiple agents such as fingers of dexterous mechanical hand is considered in this paper. In particular, the type of manipulation where the object slides between the fingers in a predefined direction. It is assumed that the sliding motion of the object is due to the external forces acting on the object. These forces can be the controlled interaction of the object and the environment or the force acting by another contacting agent. The proposed method takes advantage of the duality between the force (wrench) and velocity (twist) to determine the direction of slip velocity and magnitude of the friction force required to have local slip at the contact point(s). The method presents novel utilization of tools from screw geometry and linear algebra to determine the location of the desired slip at contact points and the magnitude of the friction forces for allowing the local slippage.