Obstacle Detection by Three Dimensional Frontal Imaging with Laser-Induced Breakdown

2002 ◽  
pp. 477-484
Author(s):  
Yoshihiro Yasumuro ◽  
Osamu Oshiro ◽  
Kunihiro Chihara ◽  
Motonori Doi ◽  
Tadao Sugiura ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Obstacle Detection ◽  
Laser Induced Breakdown

Gold Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy and Three-Dimensional Contour Imaging of an Aluminum Alloy

2020 ◽  
pp. 000370282097304
Author(s):  
Amal A. Khedr ◽  
Mahmoud A. Sliem ◽  
Mohamed Abdel-Harith
Keyword(s):  
Gold Nanoparticles ◽  
Aluminum Alloy ◽  
Three Dimensional ◽  
Plasma Temperature ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Al Alloy ◽  
Boltzmann Plot ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

In the present work, nanoparticle-enhanced laser-induced breakdown spectroscopy was used to analyze an aluminum alloy. Although LIBS has numerous advantages, it suffers from low sensitivity and low detection limits compared to other spectrochemical analytical methods. However, using gold nanoparticles helps to overcome such drawbacks and enhances the LIBS sensitivity in analyzing aluminum alloy in the current work. Aluminum was the major element in the analyzed samples (99.9%), while magnesium (Mg) was the minor element (0.1%). The spread of gold nanoparticles onto the Al alloy and using a laser with different pulse energies were exploited to enhance the Al alloy spectral lines. The results showed that Au NPs successfully improved the alloy spectral lines intensity by eight times, which could be useful for detecting many trace elements in higher matrix alloys. Under the assumption of local thermodynamic equilibrium, the Boltzmann plot was used to calculate the plasma temperature. Besides, the electron density was calculated using Mg and H lines at Mg(I) at 285.2 nm and Hα(I) at 656.2 nm, respectively. Three-dimensional contour mapping and color fill images contributed to understanding the behavior of the involved effects.

High-resolution three-dimensional compositional imaging by double-pulse laser-induced breakdown spectroscopy

2016 ◽  
Vol 11 (08) ◽  
pp. C08002-C08002 ◽  
Author(s):  
C. Schiavo ◽  
L. Menichetti ◽  
E. Grifoni ◽  
S. Legnaioli ◽  
G. Lorenzetti ◽  
...  
Keyword(s):  
High Resolution ◽  
Pulse Laser ◽  
Three Dimensional ◽  
Double Pulse ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Double Pulse Laser

scholarly journals Quantitative Determination of Cd in Soil Using Laser-Induced Breakdown Spectroscopy in Air and Ar Conditions

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2492 ◽  
Author(s):  
Xiaodan Liu ◽  
Fei Liu ◽  
Weihao Huang ◽  
Jiyu Peng ◽  
Tingting Shen ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Least Squares ◽  
Three Dimensional ◽  
Accurate Method ◽  
Laser Induced Breakdown Spectroscopy ◽  
Quantitative Detection ◽  
Support Vector ◽  
Least Squares Regression ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

Rapid detection of Cd content in soil is beneficial to the prevention of soil heavy metal pollution. In this study, we aimed at exploring the rapid quantitative detection ability of laser- induced breakdown spectroscopy (LIBS) under the conditions of air and Ar for Cd in soil, and finding a fast and accurate method for quantitative detection of heavy metal elements in soil. Spectral intensity of Cd and system performance under air and Ar conditions were analyzed and compared. The univariate model and multivariate models of partial least-squares regression (PLSR) and least-squares support vector machine (LS-SVM) of Cd under the air and Ar conditions were built, and the LS-SVM model under the Ar condition obtained the best performance. In addition, the principle of influence of Ar on LIBS detection was investigated by analyzing the three-dimensional profile of the ablation crater. The overall results indicated that LIBS combined with LS-SVM under the Ar condition could be a useful tool for the accurate quantitative detection of Cd in soil and could provide reference for environmental monitoring.

scholarly journals Rules to fly by: pigeons navigating horizontal obstacles limit steering by selecting gaps most aligned to their flight direction

2017 ◽  
Vol 7 (1) ◽  
pp. 20160093 ◽  
Author(s):  
Ivo G. Ros ◽  
Partha S. Bhagavatula ◽  
Huai-Ti Lin ◽  
Andrew A. Biewener
Keyword(s):  
Flight Control ◽  
Three Dimensional ◽  
Obstacle Detection ◽  
Head Movements ◽  
Flight Mechanics ◽  
Unmanned Aerial Systems ◽  
Natural Environments ◽  
Motion Vision ◽  
Flight Direction ◽  
Wing Stroke

Flying animals must successfully contend with obstacles in their natural environments. Inspired by the robust manoeuvring abilities of flying animals, unmanned aerial systems are being developed and tested to improve flight control through cluttered environments. We previously examined steering strategies that pigeons adopt to fly through an array of vertical obstacles (VOs). Modelling VO flight guidance revealed that pigeons steer towards larger visual gaps when making fast steering decisions. In the present experiments, we recorded three-dimensional flight kinematics of pigeons as they flew through randomized arrays of horizontal obstacles (HOs). We found that pigeons still decelerated upon approach but flew faster through a denser array of HOs compared with the VO array previously tested. Pigeons exhibited limited steering and chose gaps between obstacles most aligned to their immediate flight direction, in contrast to VO navigation that favoured widest gap steering. In addition, pigeons navigated past the HOs with more variable and decreased wing stroke span and adjusted their wing stroke plane to reduce contact with the obstacles. Variability in wing extension, stroke plane and wing stroke path was greater during HO flight. Pigeons also exhibited pronounced head movements when negotiating HOs, which potentially serve a visual function. These head-bobbing-like movements were most pronounced in the horizontal (flight direction) and vertical directions, consistent with engaging motion vision mechanisms for obstacle detection. These results show that pigeons exhibit a keen kinesthetic sense of their body and wings in relation to obstacles. Together with aerodynamic flapping flight mechanics that favours vertical manoeuvring, pigeons are able to navigate HOs using simple rules, with remarkable success.

scholarly journals Breaking the absorption limit of Si toward SWIR wavelength range via strain engineering

2020 ◽  
Vol 6 (31) ◽  
pp. eabb0576
Author(s):  
Ajit K. Katiyar ◽  
Kean You Thai ◽  
Won Seok Yun ◽  
JaeDong Lee ◽  
Jong-Hyun Ahn
Keyword(s):  
Wavelength Range ◽  
Near Infrared ◽  
Three Dimensional ◽  
Strain Engineering ◽  
Obstacle Detection ◽  
Optical Bandgap ◽  
Engineering Material ◽  
Infrared Spectral Range ◽  
Infrared Spectral ◽  
Microelectronics Industry

Silicon has been widely used in the microelectronics industry. However, its photonic applications are restricted to visible and partial near-infrared spectral range owing to its fundamental optical bandgap (1.12 eV). With recent advances in strain engineering, material properties, including optical bandgap, can be tailored considerably. This paper reports the strain-induced shrinkage in the Si bandgap, providing photosensing well beyond its fundamental absorption limit in Si nanomembrane (NM) photodetectors (PDs). The Si-NM PD pixels were mechanically stretched (biaxially) by a maximum strain of ~3.5% through pneumatic pressure–induced bulging, enhancing photoresponsivity and extending the Si absorption limit up to 1550 nm, which is the essential wavelength range of the lidar sensors for obstacle detection in self-driving vehicles. The development of deformable three-dimensional optoelectronics via gas pressure–induced bulging also facilitated the realization of unique device designs with concave and convex hemispherical architectures, which mimics the electronic prototypes of biological eyes.

Three-dimensional elemental imaging of Li-ion solid-state electrolytes using fs-laser induced breakdown spectroscopy (LIBS)

2015 ◽  
Vol 30 (11) ◽  
pp. 2295-2302 ◽  
Author(s):  
Huaming Hou ◽  
Lei Cheng ◽  
Thomas Richardson ◽  
Guoying Chen ◽  
Marca Doeff ◽  
...  
Keyword(s):  
Solid Electrolytes ◽  
Three Dimensional ◽  
Chemical Imaging ◽  
Laser Induced Breakdown Spectroscopy ◽  
Li Ion Battery ◽  
Elemental Imaging ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Fs Laser ◽  
Li Ion

We demonstrate a new way for direct 3D chemical imaging of Li-ion battery solid-electrolytes by combining femtosecond-LIBS with advanced visualization protocols.

scholarly journals A MATLAB-Based Application Development Using a 3D PMD Camera for a Mobile Robot

2011 ◽  
Author(s):  
Mohammad Chami ◽  
Holger Voos
Keyword(s):  
Mobile Robot ◽  
Mobile Robotics ◽  
Three Dimensional ◽  
Obstacle Detection ◽  
Application Development ◽  
Communication Interface ◽  
Pose Determination ◽  
Data Acquisition Board ◽  
Time Distance ◽  
Robotic Applications

Three-dimensional sensing is a vital field in mobile robotic applications. This work proposes an application of a Time-of-Flight 3D Photonic Mixer Device (PMD) camera for the navigation of an Omni-directional mobile robot. The 3D PMD camera enables real time distance detection as well as the capturing of grayscale images. In our framework, the application of the 3D PMD camera is aimed at solving the problem of environmental perception in mobile robotics. In this paper, we present the development of a MATLAB-based kit for the control of an Omni-directional mobile robot supported by a data acquisition board. The communication interface of the camera, used to close the system’s control loop, has been also developed. We further present results of different experiments including online obstacle detection and avoidance. In addition, an adaptive pose determination for the robot is proposed.

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