Scattering or Pushing for Object Singulation in Cluttered Environment: Case Study with Soma Cube

Abstract

This paper proposes a hybrid singulation approach combining dynamic scattering and pushing techniques. Using the impulse-based dynamic model, a guideline is provided to decide whether scattering or pushing is conducted for object singulation. The Soma cube consisting of seven blocks is used as the test example. The target is to singulate all the blocks. The dynamic scattering technique was initially applied to separate blocks in the formation. However, scattering alone does not provide target singulation in all the cases. So we combine the quasi-static pushing technique to complete the singulation of all the blocks. In pushing, image segmentation based on principal component analysis (PCA) algorithm was employed to singulate multiple blocks in clutter and prehensile manipulation was used to remove isolated blocks. Several 2-D formations of the Soma cube are used as the test cases. To validate the effectiveness of our approach, we have conducted comparative analysis which clearly shows that the hybrid singulation achieves singulation in much less time as compared to the pure pushing approach.

Domain-Independent Disperse and Pick Method for Robotic Grasping

“…This method assumes that the pushing surface is planar with a homogeneous friction coefficient and the objects are identifiable in the scene which is not the case given a clutter of novel objects with various shapes and sizes. Similarly, a dynamic-push (impulsed based controlled scattering of objects by collision) [24] and a hybrid (staticdynamic) approach [25] are also proposed that use an analytical method to estimate push velocity, starting point, and principal component analysis to define push vector on the segmented images. This method heavily depends on learning certain properties of the scene (i.e.…”