Hand-Object Contact Force Synthesis for Manipulating Objects by Exploiting Environment

In this paper, we study the problem of computing grasping forces for quasi-static manipulation of large and heavy objects, by exploiting object-environment contacts. We present a general formulation of this problem as a Second-Order Cone Program (SOCP) that considers (i) contact friction constraints at the object-manipulator contacts and object-environment contacts, (ii) force/moment equilibrium constraints, and (iii) manipulator joint torque constraints. The SOCP formulation implies that the optimal grasping forces for manipulating objects with the help of the environment can be computed efficiently. Different optimization objectives like minimizing contact forces at the object-manipulator contacts or minimizing joint torques of manipulators can be considered. We evaluated our method by simulations of single-handed and dual-handed manipulation scenarios.