On the stability of an object in multi-finger grasping

Deals with the stability of a rigid body under multiple contact forces. First, the problem considered at the force planning level, and the stability of a force distribution is formulated. Analytical conditions for the stability of a force distribution, considered under unilateral frictional constraints, are studied on an illustrative example, Next, it is shown that stabilization of an unstable force distribution can be done by a simple control law. The stability conditions for this control law are formulated in terms of the force-induced stiffness tensor and the control-spring-induced stiffness tensor calculated at the stiffness center. Finally, comments on the contradiction between the Lyapunov stability and the contact stability of the objects are drawn