8,533 research outputs found
TVL<sub>1</sub> Planarity Regularization for 3D Shape Approximation
The modern emergence of automation in many industries has given impetus to extensive research into mobile robotics. Novel perception technologies now enable cars to drive autonomously, tractors to till a field automatically and underwater robots to construct pipelines. An essential requirement to facilitate both perception and autonomous navigation is the analysis of the 3D environment using sensors like laser scanners or stereo cameras. 3D sensors generate a very large number of 3D data points when sampling object shapes within an environment, but crucially do not provide any intrinsic information about the environment which the robots operate within.
This work focuses on the fundamental task of 3D shape reconstruction and modelling from 3D point clouds. The novelty lies in the representation of surfaces by algebraic functions having limited support, which enables the extraction of smooth consistent implicit shapes from noisy samples with a heterogeneous density. The minimization of total variation of second differential degree makes it possible to enforce planar surfaces which often occur in man-made environments. Applying the new technique means that less accurate, low-cost 3D sensors can be employed without sacrificing the 3D shape reconstruction accuracy
Joint Compressed Sensing and Manipulation of Wireless Emissions with Intelligent Surfaces
Programmable, intelligent surfaces can manipulate electromagnetic waves
impinging upon them, producing arbitrarily shaped reflection, refraction and
diffraction, to the benefit of wireless users. Moreover, in their recent form
of HyperSurfaces, they have acquired inter-networking capabilities, enabling
the Internet of Material Properties with immense potential in wireless
communications. However, as with any system with inputs and outputs, accurate
sensing of the impinging wave attributes is imperative for programming
HyperSurfaces to obtain a required response. Related solutions include field
nano-sensors embedded within HyperSurfaces to perform minute measurements over
the area of the HyperSurface, as well as external sensing systems. The present
work proposes a sensing system that can operate without such additional
hardware. The novel scheme programs the HyperSurface to perform compressed
sensing of the impinging wave via simple one-antenna power measurements. The
HyperSurface can jointly be programmed for both wave sensing and wave
manipulation duties at the same time. Evaluation via simulations validates the
concept and highlight its promising potential.Comment: Published at IEEE DCOSS 2019 / IoT4.0 workshop
(https://www.dcoss.org/workshops.html). Funded by the European Union via the
Horizon 2020: Future Emerging Topics - Research and Innovation Action call
(FETOPEN-RIA), grant EU736876, project VISORSURF (http://www.visorsurf.eu
A Semi-Lagrangian Scheme with Radial Basis Approximation for Surface Reconstruction
We propose a Semi-Lagrangian scheme coupled with Radial Basis Function
interpolation for approximating a curvature-related level set model, which has
been proposed by Zhao et al. in \cite{ZOMK} to reconstruct unknown surfaces
from sparse, possibly noisy data sets. The main advantages of the proposed
scheme are the possibility to solve the level set method on unstructured grids,
as well as to concentrate the reconstruction points in the neighbourhood of the
data set, with a consequent reduction of the computational effort. Moreover,
the scheme is explicit. Numerical tests show the accuracy and robustness of our
approach to reconstruct curves and surfaces from relatively sparse data sets.Comment: 14 pages, 26 figure
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