scholarly journals Vision-Less Sensing for Autonomous Micro-Drones

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5293
Author(s):  
Simon Pikalov ◽  
Elisha Azaria ◽  
Shaya Sonnenberg ◽  
Boaz Ben-Moshe ◽  
Amos Azaria
Keyword(s):  
Optical Flow ◽  
Field Experiments ◽  
Total Darkness ◽  
Complete Model ◽  
Complex Tasks ◽  
Obstacle Avoiding ◽  
Complex Building

This work presents a concept of intelligent vision-less micro-drones, which are motivated by flying animals such as insects, birds, and bats. The presented micro-drone (named BAT: Blind Autonomous Tiny-drone) can perform bio-inspired complex tasks without the use of cameras. The BAT uses LIDARs and self-emitted optical-flow in order to perform obstacle avoiding and maze-solving. The controlling algorithms were implemented on an onboard micro-controller, allowing the BAT to be fully autonomous. We further present a method for using the information collected by the drone to generate a detailed mapping of the environment. A complete model of the BAT was implemented and tested using several scenarios both in simulation and field experiments, in which it was able to explore and map complex building autonomously even in total darkness.

scholarly journals An Improved Fractional-Order Optical Flow Model for Motion Estimation

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Bin Zhu ◽  
Lianfang Tian ◽  
Qiliang Du ◽  
Qiuxia Wu ◽  
Lixin Shi
Keyword(s):  
Flow Field ◽  
Motion Estimation ◽  
Optical Flow ◽  
Fractional Order ◽  
Field Experiments ◽  
Flow Model ◽  
Lagrange Equation ◽  
Taylor Series Expansion ◽  
Constraint Equation ◽  
Optical Flow Field

The Horn and Schunck (HS) optical flow model cannot preserve discontinuity of motion estimation and has low accuracy especially for the image sequence, which includes complex texture. To address this problem, an improved fractional-order optical flow model is proposed. In particular, the fractional-order Taylor series expansion is applied in the brightness constraint equation of the HS model. The fractional-order flow field derivative is also used in the smoothing constraint equation. The Euler-Lagrange equation is utilized for the minimization of the energy function of the fractional-order optical flow model. Two-dimensional fractional differential masks are proposed and applied to the calculation of the model simplification. Considering the spatiotemporal memory property of fractional-order, the algorithm preserves the edge discontinuity of the optical flow field while improving the accuracy of the estimation of the dense optical flow field. Experiments on Middlebury datasets demonstrate the predominance of our proposed algorithm.

Electron Microscopy of the Shape of Small Metal Particles

1977 ◽  
Vol 35 ◽  
pp. 300-301
Author(s):  
M. Jose Yacaman
Keyword(s):  
Electron Microscopy ◽  
Metal Particle ◽  
Field Experiments ◽  
Size Range ◽  
Dark Field ◽  
Metal Particles ◽  
Bragg Condition ◽  
Crystal Particle ◽  
Small Metal Particle ◽  
Small Metal Particles

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.

Iron–oxygen interaction in silicon: A combined XBIC/XRF-EBIC-DLTS study of precipitation and complex building

2009 ◽  
Vol 404 (23-24) ◽  
pp. 4645-4648
Author(s):  
M. Trushin ◽  
O. Vyvenko ◽  
W. Seifert ◽  
G. Jia ◽  
M. Kittler
Keyword(s):  
Complex Building ◽  
Oxygen Interaction

Enhancing Learning, Performance, and Adaptability for Complex Tasks

2005 ◽  
Author(s):  
Steve W. J. Kozlowski ◽  
◽  
Richard P. DeShon
Keyword(s):  
Learning Performance ◽  
Complex Tasks

Successful field experiments: Getting in, getting the data, getting published

2010 ◽  
Author(s):  
Susan M. Kochanowski ◽  
Charles F. Seifert ◽  
Gary A. Yukl ◽  
Dov Eden ◽  
Gary P. Latham
Keyword(s):  
Field Experiments

Motion correction in PET/CT

2005 ◽  
Vol 44 (S 01) ◽  
pp. S46-S50 ◽  
Author(s):  
M. Dawood ◽  
N. Lang ◽  
F. Büther ◽  
M. Schäfers ◽  
O. Schober ◽  
...  
Keyword(s):  
Optical Flow ◽  
Motion Correction ◽  
Motion Vector ◽  
Emission Tomography ◽  
Cardiac Pet ◽  
Novel Approach ◽  
Positron Emission ◽  
Pet Ct ◽  
Flow Algorithm ◽  
Motion Vector Field

Summary:Motion in PET/CT leads to artifacts in the reconstructed PET images due to the different acquisition times of positron emission tomography and computed tomography. The effect of motion on cardiac PET/CT images is evaluated in this study and a novel approach for motion correction based on optical flow methods is outlined. The Lukas-Kanade optical flow algorithm is used to calculate the motion vector field on both simulated phantom data as well as measured human PET data. The motion of the myocardium is corrected by non-linear registration techniques and results are compared to uncorrected images.

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