Simultaneous and Realistic Contact and Force Planning in Grasping

Traditional approaches in grasping consider separately the planning of contact points and forces. This often leads to optimally simulated grasps that fail in a real execution when the forces applied at the chosen contact points cannot resist expected perturbations like the own object weight. This paper presents a method that combines a grasp planner with the computation of grasp forces, which provides contact points and contact forces that take into account joint and torque limits of the robotic hand for fingertip grasps. The planner starts with a given hand pose relative to the object, and uses the concept of reachable independent contact regions to obtain a set of force closure grasps. Within this set, the grasp that best counteracts a given external wrench is chosen. The evaluation examples illustrate how the capabilities of the robotic hand can be used more effectively by this joint planning approach