This article examines the grasping quality problem and suggests a formulation that can capture the major mechanisms that generate the human grasping quality sense. Here, the quality of a grasp is examined from the gripper, object, and grasping‐configuration perspectives. These perspectives are incorporated into the formulation by selecting an appropriate objective function that is minimized subject to constraints that represent the geometry, friction, and force‐balance conditions of a grasp. The quality of a grasp is depicted as a polar plot that demonstrates the dependency of grasping quality on the external‐loading direction. The suggested grasping quality measures possess characteristics that are in agreement with basic human intuition. In particular this article proves that the three proposed quality measures are improved when the number of contact points is increased. In summary, the suggested grasping quality formulation captures some of the physical mechanisms that characterize a human grasp, and therefore it may lead to a powerful mathematical model of the human grasping quality sense. © 1995 John Wiley & Sons, Inc.

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We consider an optimization formulation that captures the quality of a grasp. In this model the object geometry, finger contact points and the magnitude of the external load are given. Perturbation of these parameters from their nominal values might lead to significant variations on the predicted grasping quality measures. In this paper we study the sensitivity of a class of grasping quality functions subject to these perturbations and introduce a global sensitivity measure together with a computational procedure to evaluate it. Our analysis is developed within the framework of sensitivity theory and dual methods of nonlinear programming. Numerical simulations supporting the theoretical analysis are presented.