scholarly journals Evaluation of Surface Slope Irregularity in Linear Parabolic Solar Collectors

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
F. Francini ◽  
D. Fontani ◽  
P. Sansoni ◽  
L. Mercatelli ◽  
D. Jafrancesco ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Solar Collector ◽  
Digital Camera ◽  
Surface Slope ◽  
Logistic Management ◽  
Measuring Surface ◽  
Light Rays ◽  
Surface Irregularities ◽  
Reflector Surface ◽  
Defective Surface

The paper describes a methodology, very simple in its application, for measuring surface irregularities of linear parabolic collectors. This technique was principally developed to be applied in cases where it is difficult to use cumbersome instruments and to facilitate logistic management. The instruments to be employed are a digital camera and a grating. If the reflector surface is defective, the image of the grating, reflected on the solar collector, appears distorted. Analyzing the reflected image, we can obtain the local slope of the defective surface. These profilometric tests are useful to identify and monitor the mirror portions under mechanical stress and to estimate the losses caused by the light rays deflected outside the absorber.

scholarly journals Deep Quality Assessment of a Solar Reflector Based on Synthetic Data: Detecting Surficial Defects from Manufacturing and Use Phase

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5481
Author(s):  
Alexios Papacharalampopoulos ◽  
Konstantinos Tzimanis ◽  
Kyriakos Sabatakakis ◽  
Panagiotis Stavropoulos
Keyword(s):  
Quality Assessment ◽  
Computer Aided Design ◽  
Synthetic Data ◽  
Small Time ◽  
Self Monitoring ◽  
Time Period ◽  
Surface Irregularities ◽  
Reflector Surface ◽  
Aided Design ◽  
Full Utilization

Vision technologies are used in both industrial and smart city applications in order to provide advanced value products due to embedded self-monitoring and assessment services. In addition, for the full utilization of the obtained data, deep learning is now suggested for use. To this end, the current work presents the implementation of image recognition techniques alongside the original the quality assessment of a Parabolic Trough Collector (PTC) reflector surface to locate and identify surface irregularities by classifying images as either acceptable or non-acceptable. The method consists of a three-step solution that promotes an affordable implementation in a relatively small time period. More specifically, a 3D Computer Aided Design (CAD) of the PTC was used for the pre-training of neural networks, while an aluminum reflector surface was used to verify algorithm performance. The results are promising, as this method proved applicable in cases where the actual part was manufactured in small batches or under the concept of customized manufacturing. Consequently, the algorithm is capable of being trained with a limited number of data.

scholarly journals Measurement Accuracy Investigation of Touch Trigger Probe with Five-Axis Machine Tools

2016 ◽  
Vol 63 (4) ◽  
pp. 495-510 ◽  
Author(s):  
Md. Mizanur Rahman ◽  
J.R.R. Mayer
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Accuracy Assessment ◽  
Cutting Fluid ◽  
Surface Wetness ◽  
Measuring Surface ◽  
Surface Irregularities ◽  
Touch Trigger Probe ◽  
Compact Design ◽  
Five Axis

Abstract The touch trigger probe plays an important role in modern metrology because of its robust and compact design with crash protection, long life and excellent repeatability. Aside from coordinate measuring machines (CMM), touch trigger probes are used for workpiece location on a machine tool and for the accuracy assessment of the machine tools. As a result, the accuracy of the measurement is a matter of interest to the users. The touch trigger probe itself as well as the measuring surface, the machine tool, measuring environment etc. contribute to measurement inaccuracies. The paper presents the effect of surface irregularities, surface wetness due to cutting fluid and probing direction on probing accuracy on a machine tool.

Comparative Study of Solar Optics for Paraboloidal Concentrators

1980 ◽  
Vol 102 (4) ◽  
pp. 305-315 ◽  
Author(s):  
L. Wen ◽  
L. Huang ◽  
P. Poon ◽  
W. Carley
Keyword(s):  
Flux Distribution ◽  
Computational Method ◽  
Optical Parameters ◽  
Solar Concentrator ◽  
Surface Slope ◽  
Algebraic Form ◽  
Reflector Surface ◽  
Slope Error ◽  
Definition Of ◽  
Limb Darkening

Different analytical methods for computing the flux distribution on the focal plane of a paraboloidal solar concentrator are reviewed. An analytical solution in algebraic form is also derived for an idealized model. The effects resulting from using different assumptions in the definition of optical parameters used in these methodologies are compared and discussed in detail. These parameters include solar irradiance distribution (limb darkening and circumsolar), reflector surface specular spreading, surface slope error, and concentrator pointing inaccuracy. The type of computational method selected for use depends on the maturity of the design and the data available at the time the analysis is made.

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