STATIC STABILITY ANALYSIS OF GRASPING MULTIPLE OBJECTS IN 2D

Abstract

Human hands perform dexterous and fine manipulation of multiple objects. Multifingered robotic hands also have potential ability executing similar manipulation. This paper analyzes static stability of grasping multiple objects in two dimensions to enhance dexterity of robotic hands. Each finger is replaced with a 2D spring model. Not only frictional contact but also frictionless contact is considered. Grasp stiffness matrices of multiple planar objects are derived with consideration of contact friction property. Grasp stability is evaluated by eigenvalues of the matrices. Configuration (position and orientation) displacement of the objects is decomposed into stable directions and unstable directions by using corresponding eigenvectors. Effectiveness of our proposed method is demonstrated through numerical examples. Our proposed method is applicable to grasp position planning and fixture position planning.