Grasp stability analysis of multiple planar objects

This paper analyzes static grasp stability of multiple planar objects. To accomplish tasks efficiently, multiple objects are grasped and manipulated by a robot hand. In order to design stable grasp, grasp stability of multiple objects is quantitatively evaluated. Each finger is replaced with a 2D spring model, and the grasp stability is evaluated from the viewpoint of potential energy stored in the grasp. From this analysis, we have the following contributions: grasp stiffness matrices are derived for multiple planar objects with any friction property. The effect of grasp parameters (contact position, direction of contact normal, curvature at contact point, contact force, and contact friction) is clarified. The grasp stability is evaluated from eigenvalues and eigenvectors of the matrices. Effectiveness of our proposed method is demonstrated through numerical examples.