Empty the Basket - A Shape Based Learning Approach for Grasping Piles of Unknown Objects

This paper presents a novel approach to emptying a basket filled with a pile of objects. Form, size, position, orientation and constellation of the objects are unknown. Additional challenges are to localize the basket and treat it as an obstacle, and to cope with incomplete point cloud data. There are three key contributions. First, we introduce Height Accumulated Features (HAF) which provide an efficient way of calculating grasp related feature values. The second contribution is an extensible machine learning system for binary classification of grasp hypotheses based on raw point cloud data. Finally, a practical heuristic for selection of the most robust grasp hypothesis is introduced. We evaluate our system in experiments where a robot was required to autonomously empty a basket with unknown objects on a pile. Despite the challenging scenarios, our system succeeded each time.