Planning Grasps for a Robot Hand in the Presence of Obstacles

In grasp planning for a robot hand, the impact of the environment geometry on grasp choice is often of paramount importance. This paper presents a partial solution to the problem of tting a hand to an object in a given environment. Information provided by a set of ngertip contact regions or by a grasp prototype is exploited to e ciently compute the space of wrist con gurations from which the grasp speci cations can be met. The size and shape of this solution space re ect the constraints imposed by the environment geometry; they can be used to compare a grasp to others or to resolve grasp symmetries (e.g. in a wrap grasp of a cylinder). A quality metric computed over the solution space can be used to optimize a grasp. The paper describes a general method for computing this solution space, and presents a parallel implementation. Examples demonstrate grasp comparison and symmetry resolution.