Learning to Singulate Objects using a Push Proposal Network

Learning to act in unstructured environments, such as cluttered piles of objects, poses a substantial challenge for manipulation robots. We present a novel neural network-based approach that separates unknown objects in clutter by selecting favourable push actions. Our network is trained from data collected through autonomous interaction of a PR2 robot with randomly organized tabletop scenes. The model is designed to propose meaningful push actions based on over-segmented RGB-D images. We evaluate our approach by singulating up to 8 unknown objects in clutter. We demonstrate that our method enables the robot to perform the task with a high success rate and a low number of required push actions. Our results based on real-world experiments show that our network is able to generalize to novel objects of various sizes and shapes, as well as to arbitrary object configurations. Videos of our experiments can be viewed at http://robotpush.cs.uni-freiburg.deComment: International Symposium on Robotics Research (ISRR) 2017, videos: http://robotpush.cs.uni-freiburg.d

Simple one-pot syntheses and characterizations of free fluoride- and bifluoride-containing polymers soluble in non-aqueous solvents

One of the problems that arise with bifluoride- or fluoride-containing compounds is their poor solubility in non-aqueous solvents. We report herein a facile one-pot synthesis and the chemical analysis of fluoride/bifluoride-containing polymers, which are soluble in MeCN. Different polymers, such as Polyvinylacetate or Polyethylene imine and saccharides, such as maltodextrin, were complexed with ammonium (bi)fluoride using hydrogen bonds to form the desired (bi)fluoride-containing compounds. The newly formed hydrogen bonding (bi)fluoride-doped polymer matrices were analyzed using infrared and nuclear magnetic resonance spectroscopies, and X-ray diffraction. The promising materials also underwent impedance spectroscopy, conductivity measurements and preliminary tests as electrolytes for room temperature fluoride ion batteries along with an analysis of their performance

Insights into the petrogenesis of an intraplate volcanic province: Sr-Nd-Pb-Hf isotope geochemistry of the Bathymetrists Seamount Province, eastern equatorial Atlantic

Unlike the well-studied narrow hotspot tracks, the origin of broadly distributed seamount provinces remains a topic of conjecture. Here we present major and trace element and Sr-Nd-Hf-Pb double spike isotope data of a comprehensive sample suite from the Bathymetrists Seamount Province, a broad belt of submarine volcanoes in the eastern equatorial Atlantic, and from the neighboring Cape Verde Ridge, a topographic high on the shoulder of a local fracture zone. The major and trace element results are consistent with the Bathymetrists Seamount Province having formed in an intraplate setting. The isotopic composition of the seamount lavas resemble a HIMU-like signature (206Pb/204Pbin = 19.23–20.35) similar to the nearby St. Helena hotspot composition. Based on plate tectonic reconstructions, a formation of the Bathymetrists Seamount Province by the postulated Sierra Leone plume, believed to be responsible for the geochemical anomaly at the mid ocean ridge at 1.7°N and the nearby St. Peter and Pauls rocks, is not supported. An alternative model that the Bathymetrists Seamount Province was created by edge driven convection in the upper mantle along the boundary of the neighboring Sierra Leone Rise plateau is also not supported by the available data. Plate tectonic reconstructions, however, are consistent with a hotspot origin for the Bathymetrists Seamount Province, as is the presence of a seismic tomographic anomaly at the southwest end of the seamount belt