Unknown object grasping by using concavity

Reducing the grasp candidates for unknown object grasping while maintaining grasp stability is the goal of this paper. In this paper, we propose an efficient and straight forward unknown object grasping method by using concavities of the unknown objects to significantly reduce the grasp candidates. Shortest path concavity is first employed to work out the concavity value for every vertex of the unknown objects followed by concavity extraction to obtain the most salient concave areas. Grasp candidates are then generated on the most salient concave areas and evaluated by using force balance computation. Grasp candidates are ranked according to the result of force balance computation and the manipulability of every grasp candidate. The grasp with the best force balance and manipulability is chosen as the final grasp. In order to verify the effectiveness of our algorithm, some unknown objects commonly used by other papers about unknown object grasping are used to do simulations and favorable performance is obtained.