Improved method for computation of grasp quality metric using minimal breaking force on objects

In grasping, one fundamental question is to ask how well a grasp can resist external disturbance. Canonically, the solution of this question lies in calculating the set of wrenches that can be generated by the grasp assuming some limitation of the hand and measurement of the extreme point in some direction of that set. Using wrenches comes with two issues: the dependency on the choice of the origin and the difference of unit of force and torque. Strandberg and Wahlberg proposed another quality metric that takes into account the object being grasp [1]. This solves the aforementioned problem but with the higher cost of computation. Our work proposes improvement that significantly reduces the running time of the method. Our key observation is that the original quality metric spends most of the time iterating object vertices and wrenches that is not needed. By applying a convex hull, we are able to reduce the number of vertices needed in the calculation. We also implement some other implementation and include numerical example that illustrates the speed up of our method.