  Many fabric handling and 2D deformable material tasks in homes and industry
require singulating layers of material such as opening a bag or arranging
garments for sewing. In contrast to methods requiring specialized sensing or
end effectors, we use only visual observations with ordinary parallel jaw
grippers. We propose SLIP: Singulating Layers using Interactive Perception, and
apply SLIP to the task of autonomous bagging. We develop SLIP-Bagging, a
bagging algorithm that manipulates a plastic or fabric bag from an unstructured
state, and uses SLIP to grasp the top layer of the bag to open it for object
insertion. In physical experiments, a YuMi robot achieves a success rate of 67%
to 81% across bags of a variety of materials, shapes, and sizes, significantly
improving in success rate and generality over prior work. Experiments also
suggest that SLIP can be applied to tasks such as singulating layers of folded
cloth and garments. Supplementary material is available at
https://sites.google.com/view/slip-bagging/.
