90,905 research outputs found
3D Object Reconstruction from Hand-Object Interactions
Recent advances have enabled 3d object reconstruction approaches using a
single off-the-shelf RGB-D camera. Although these approaches are successful for
a wide range of object classes, they rely on stable and distinctive geometric
or texture features. Many objects like mechanical parts, toys, household or
decorative articles, however, are textureless and characterized by minimalistic
shapes that are simple and symmetric. Existing in-hand scanning systems and 3d
reconstruction techniques fail for such symmetric objects in the absence of
highly distinctive features. In this work, we show that extracting 3d hand
motion for in-hand scanning effectively facilitates the reconstruction of even
featureless and highly symmetric objects and we present an approach that fuses
the rich additional information of hands into a 3d reconstruction pipeline,
significantly contributing to the state-of-the-art of in-hand scanning.Comment: International Conference on Computer Vision (ICCV) 2015,
http://files.is.tue.mpg.de/dtzionas/In-Hand-Scannin
Grasping unknown objects in clutter by superquadric representation
© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper, a quick and efficient method is presented for grasping unknown objects in clutter. The grasping method relies on real-time superquadric (SQ) representation of partial view objects and incomplete object modelling, well suited for unknown symmetric objects in cluttered scenarios which is followed by optimized antipodal grasping. The incomplete object models are processed through a mirroring algorithm that assumes symmetry to first create an approximate complete model and then fit for SQ representation. The grasping algorithm is designed for maximum force balance and stability, taking advantage of the quick retrieval of dimension and surface curvature information from the SQ parameters. The pose of the SQs with respect to the direction of gravity is calculated and used together with the parameters of the SQs and specification of the gripper, to select the best direction of approach and contact points. The SQ fitting method has been tested on custom datasets containing objects in isolation as well as in clutter. The grasping algorithm is evaluated on a PR2 robot and real time results are presented. Initial results indicate that though the method is based on simplistic shape information, it outperforms other learning based grasping algorithms that also work in clutter in terms of time-efficiency and accuracy.Peer ReviewedPostprint (author's final draft
Component-wise modeling of articulated objects
We introduce a novel framework for modeling articulated objects based on the aspects of their components. By decomposing the object into components, we divide the problem in smaller modeling tasks. After obtaining 3D models for each component aspect by employing a shape deformation paradigm, we merge them together, forming the object components. The final model is obtained by assembling the components using an optimization scheme which fits the respective 3D models to the corresponding apparent contours in a reference pose. The results suggest that our approach can produce realistic 3D models of articulated objects in reasonable time
Near-infrared polarimetric study of the bipolar nebula IRAS 19312+1950
We obtained H-band polarimetric data of IRAS 19312+1950 using the
near-infrared camera (CIAO) on the 8 m Subaru telescope. In order to
investigate the physical properties of the central star and the nebula, we
performed dust radiative transfer modeling and compared the model results with
the observed spectral energy distributions (SEDs), the radial profiles of the
total intensity image, and the fraction of linear polarization map. The total
intensity image shows a nearly spherical core with ~3" radius, an S-shaped arm
extending ~10" in the northwest to southeast direction, and an extended lobe
towards the southwest. The polarization map shows a centro-symmetric vector
alignment in almost the entire nebula and low polarizations along the S-shaped
arm. These results suggest that the nebula is accompanied by a central star,
and the S-shaped arm has a physically ring-like structure. From our radiative
transfer modeling, we estimated the stellar temperature, the bolometric
luminosity, and the current mass-loss rate to be 2800 K, 7000 L_sun, and
5.3x10^{-6} M_sun yr^{-1}, respectively. Taking into account previous
observational results, such as the detection of SiO maser emissions and
silicate absorption feature in the 10 m spectrum, our dust radiative
transfer analysis based on our NIR imaging polarimetry suggests that (1) the
central star of IRAS 19312+1950 is likely to be an oxygen-rich, dust-enshrouded
AGB star and (2) most of the circumstellar material originates from other
sources (e.g. ambient dark clouds) rather than as a result of mass loss from
the central star.Comment: 8 pages with 4 figure
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