scholarly journals Accuracy test of laser station under conditions of air turbulence

2017 ◽  
Vol 11 (3) ◽  
pp. 67
Author(s):  
Janusz Kwiecień ◽  
Adam Bujarkiewicz
Keyword(s):  
Author(s):  
Janusz Kwiecien

Laser tracking for interior industrial metrology is discussed. In this work, the effects of air turbulence on the angle of laser wave propagation is analyzed in the absence of the effects associated with other meteorological parameters (pressure, humidity) and particulate pollutants (dust, smoke). This analysis establishes the effectiveness of laser tracking under turbulent air conditions and quantification of deviations in the angular and linear accuracy from those provided by the manufacturer. An experimental setup and associated measurement method to determine the turbulence structure coefficient are described. It was found that turbulent air conditions resulted in a radical decrease in measurement accuracy. The reduction in accuracy was evidenced by a decrease in power and an increase in standard deviation of the laser beam, as well as a decline in the angle and distance measurement precision. The experimental measurements show a high correlation to predicted values.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Sumedh Yadav ◽  
Mathis Bode

Abstract A scalable graphical method is presented for selecting and partitioning datasets for the training phase of a classification task. For the heuristic, a clustering algorithm is required to get its computation cost in a reasonable proportion to the task itself. This step is succeeded by construction of an information graph of the underlying classification patterns using approximate nearest neighbor methods. The presented method consists of two approaches, one for reducing a given training set, and another for partitioning the selected/reduced set. The heuristic targets large datasets, since the primary goal is a significant reduction in training computation run-time without compromising prediction accuracy. Test results show that both approaches significantly speed-up the training task when compared against that of state-of-the-art shrinking heuristics available in LIBSVM. Furthermore, the approaches closely follow or even outperform in prediction accuracy. A network design is also presented for a partitioning based distributed training formulation. Added speed-up in training run-time is observed when compared to that of serial implementation of the approaches.


Author(s):  
Masaki Michihata ◽  
Zhao Zheng ◽  
Daiki Funaiwa ◽  
Sojiro Murakami ◽  
Shotaro Kadoya ◽  
...  

AbstractIn this paper, we propose an in-process measurement method of the diameter of micro-optical fiber such as a tapered optical fiber. The proposed technique is based on analyzing optically scattered light generated by standing wave illumination. The proposed method is significant in that it requires an only limited measurement range and does not require a high dynamic range sensor. These properties are suitable for in-process measurement. This experiment verified that the proposed method could measure a fiber diameter as stable as ± 0.01 μm under an air turbulence environment. As a result of comparing the measured diameter distribution with those by scanning electron microscopy, it was confirmed that the proposed method has a measurement accuracy better than several hundred nanometers.


1959 ◽  
Vol 16 (5) ◽  
pp. 588-592 ◽  
Author(s):  
Werner Schwerdtfeger ◽  
Uwe Radok
Keyword(s):  

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