Evaluating the quality of grasp configurations for dextrous hands

We investigate methods for evaluating grasp configurations of multifingered robot hands. When a grasped object is subjected to externally applied forces and moments, an equilibrium of the object is achieved by contact forces which are generated by the joint torques of the fingers. Assuming that the object and fingers comprise a rigid body system, we provide a general formulation relating the contact forces with the joint torques, external forces, and moments. We define three criteria to evaluate optimal grasp configurations. The computation of the criteria requires determining eigenvalues of a matrix. The method is applicable to all types of grasps. It is not limited by the number of contacts for each fingers, the geometry of the object, nor the contact models. In the examples, several grasp configurations are compared using these criteria.