scholarly journals Uncertainty Evaluation in Vision-Based Techniques for the Surface Analysis of Composite Material Components

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4875
Author(s):  
Giulio D’Emilia ◽  
Antonella Gaspari ◽  
Emanuela Natale ◽  
Davide Ubaldi
Keyword(s):  
Process Optimization ◽  
Vision System ◽  
Uncertainty Budget ◽  
Angle Measurement ◽  
Uncertainty Evaluation ◽  
Spherical Object ◽  
Automotive Components ◽  
Complete Uncertainty ◽  
Simulation Validation ◽  
Processing Techniques

In this paper, a methodology is discussed concerning the measurement of yarn’s angle of two different glass-reinforced polypropylene matrix materials, widely used in the production of automotive components. The measurement method is based on a vision system and image processing techniques for edge detection. Measurements of angles enable, if accurate, both useful suggestions for process optimization to be made, and the reliable validation of the simulation results of the thermoplastic process. Therefore, uncertainty evaluation of angle measurement is a mandatory pre-requisite. If the image acquisition and processing is considered, many aspects influence the whole accuracy of the method; the most important have been identified and their effects evaluated with reference to two different materials, which present different optical-type characteristics. The influence of piece geometry has also been taken into account, carrying out measurements on flat sheets and on a semi-spherical object, which is a reference standard shape, to verify the effect of thermoforming and to tune the process parameters. Complete uncertainty in the order of a few degrees has been obtained, which is satisfactory for purposes of simulation validation and consequent process optimization. The uncertainty budget also allowed individuation of the most relevant causes of uncertainty for measurement process improvement.

Parachute Swing Angle Measurement in Wind Tunnel Test Based on Stereo Vision System

2013 ◽  
Vol 380-384 ◽  
pp. 837-840
Author(s):  
Jin Song ◽  
Jun Ma ◽  
Min Jiang
Keyword(s):  
Wind Tunnel ◽  
Stereo Vision ◽  
Measurement Problem ◽  
Vision System ◽  
Wind Tunnel Test ◽  
Angle Measurement ◽  
Test Method ◽  
Swing Angle ◽  
Stereo Vision System ◽  
Parachute System

Parachute system is a significant composing part of aircraft, and the swing angle is one of system security targets. To the complicated measurement problem of parachute angle in wind tunnel test, this paper describes a test method based on stereo vision system, the system is mainly composed of two CCD cameras, image acquisition card and computer. It can get 3D coordinates by stereo vision calibration and digital image processing technology, and calculate the parachute swing angle by geometry relationship. The result shows that the method succeeds, and gets the vertical and horizontal angles which are projected onto two orthogonal planes. The method has the advantage of simple system composing and good compatibility, displays much better application value.

Uncertainty Evaluation in Distance Measurement by CMM Based on Monte Carlo Method

2013 ◽  
Vol 684 ◽  
pp. 429-433 ◽  
Author(s):  
Hong Li Li ◽  
Xiao Huai Chen ◽  
Hong Tao Wang
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Evaluation Process ◽  
Mathematic Model ◽  
Distance Measurement ◽  
Uncertainty Evaluation ◽  
Measured Quantity ◽  
Complete Uncertainty ◽  
End Distance ◽  
Influence Measurement

There is presented a complete uncertainty evaluation process of end distance measurement by CMM. To begin with, the major sources of uncertainty, which would influence measurement result, are found out after analyzing, then, the general mathematic model of end distance measurement is established. Furthermore, Monte Carlo method (MCM) is used, and the uncertainty of the measured quantity is obtained. The complete results are given out, so the value of CMM is enhanced. Moreover, seen from the evaluation example, the results of uncertainty evaluation obtained from MCM method and from GUM method are compared, the comparison result indicates that the mathematic model is feasible, and using MCM method to evaluate uncertainty is easy and efficient, having practical value.

scholarly journals Optimal Estimation Method Retrievals of Stratospheric Ozone Profiles from a DIAL Lidar

2018 ◽  
Author(s):  
Ghazal Farhani ◽  
Robert J. Sica ◽  
Sophie Godin-Beekmann ◽  
Alexander Haefele
Keyword(s):  
Stratospheric Ozone ◽  
A Priori ◽  
Estimation Method ◽  
Optimal Estimation ◽  
Uncertainty Budget ◽  
Small Contribution ◽  
Vertical Resolution ◽  
Density Profiles ◽  
Complete Uncertainty ◽  
The Difference

Abstract. This paper provides a detailed description of the first principle Optimal Estimation Method (OEM) which is applied to ozone retrieval analysis using Differential Absorption Lidar (DIAL) measurements. The air density, detector dead times, background coefficients, and lidar constants are simultaneously retrieved along with ozone density profiles. Using an averaging kernel, the OEM provides the vertical resolution of the retrieval as a function of altitude. A maximum acceptable height at which the a priori has a small contribution to the retrieval is calculated for each profile as well. Moreover, a complete uncertainty budget including both systematic and statistical uncertainties is given for each individual retrieved profile. Long term stratospheric DIAL ozone measurements have been carried out at the Observatoire de Haute-Provence (OHP) since 1985. The OEM is applied to 3 nights of measurements at OHP during an intensive ozone campaign in July 2017 where coincident lidar-ozonesonde measurements are available. The retrieved ozone density profiles are in good agreement with both traditional analysis and the ozonesonde measurements. For the three nights of measurements, below 15 km the difference between the OEM and the sonde profiles is less than 25 %, at altitudes between 15 km to 25 km the difference is less than 10 %, and the OEM can successfully catch many variations of ozone which are detected in the sonde profiles due to its ability to adjust its vertical resolution as the signal varies. Above 25 km the difference between the OEM and the sonde profiles does not exceed 20 %.

scholarly journals Optimal estimation method retrievals of stratospheric ozone profiles from a DIAL

2019 ◽  
Vol 12 (4) ◽  
pp. 2097-2111 ◽  
Author(s):  
Ghazal Farhani ◽  
Robert J. Sica ◽  
Sophie Godin-Beekmann ◽  
Alexander Haefele
Keyword(s):  
Stratospheric Ozone ◽  
A Priori ◽  
Estimation Method ◽  
Optimal Estimation ◽  
Uncertainty Budget ◽  
Small Contribution ◽  
Vertical Resolution ◽  
Density Profiles ◽  
Complete Uncertainty ◽  
The Difference

Abstract. This paper provides a detailed description of a first-principle optimal estimation method (OEM) applied to ozone retrieval analysis using differential absorption lidar (DIAL) measurements. The air density, detector dead times, background coefficients, and lidar constants are simultaneously retrieved along with ozone density profiles. Using an averaging kernel, the OEM provides the vertical resolution of the retrieval as a function of altitude. A maximum acceptable height at which the a priori has a small contribution to the retrieval is calculated for each profile as well. Moreover, a complete uncertainty budget including both systematic and statistical uncertainties is given for each individual retrieved profile. Long-term stratospheric DIAL ozone measurements have been carried out at the Observatoire de Haute-Provence (OHP) since 1985. The OEM is applied to three nights of measurements at OHP during an intensive ozone campaign in July 2017 for which coincident lidar–ozonesonde measurements are available. The retrieved ozone density profiles are in good agreement with both traditional analysis and the ozonesonde measurements. For the three nights of measurements, below 15 km the difference between the OEM and the sonde profiles is less than 25 %, and at altitudes between 15 and 25 km the difference is less than 10 %; the OEM can successfully catch many variations in ozone, which are detected in the sonde profiles due to its ability to adjust its vertical resolution as the signal varies. Above 25 km the difference between the OEM and the sonde profiles does not exceed 20 %.

scholarly journals Sistem Computer Vision Pengenalan Pola Angka dan Operator Matematika Pada Permainan Kartu Angka Berbasis Jaringan Syaraf Tiruan Perceptron

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Rian Rahmanda Putra ◽  
Fery Antony
Keyword(s):  
Image Processing ◽  
Computer Vision ◽  
Vision System ◽  
Computer Vision System ◽  
Image Processing Techniques ◽  
Perceptron Algorithm ◽  
Card Number ◽  
Training Stage ◽  
Processing Techniques ◽  
Real Time Application

<p align="center"><strong><em>Abstract <br /></em></strong></p><p><em>Computer vision is an image processing by a computer to obtain information from image captured through the camera generally used in real-time application. This paper reports on the results of research conducted on computer vision system designed to be able to recognize the image number (0-9) and mathematical operators (addition (+) and subtraction (-)) in a card number figures. Computer vision system designed in this study consists of a camera on the android phone that used to captured images on the card number and the computer that has artificial neural network perceptron algorithm in identifiying images. Both components of the computer vision system are connected wirelessly through the TCP/IP Protocol. At the training stage of Perceptron ANN, 10 samples for each number and mathematical operators are used. Computer vision system built in this study also have several image processing techniques such as greyscalling, thresholding, cropping and resizing. This techniques is used to filter the information from the images captured by camera in order to get the adequate and smaller image to be processed by ANN Perceptron. Stages of testing performed three times. First testing is given picture numbers 0-3, second testing is given picture number 4-7 and third testing is given number 8-9, addition symbol and subtraction symbol. Based on testing result, system built are able to recognize 10 from 12 image rendered with a success rate of 83.33%.</em></p><p><strong><em>Keywords</em></strong><em> : Computer vision, perceptron, card number</em></p><p><em> </em></p><p align="center"><strong><em>Abstrak <br /></em></strong></p><p><em>Computer vision merupakan proses pengolahan citra oleh computer untuk mendapatkan informasi dari citra yang ditangkap melalui kamera yang umumnya digunakan pada aplikasi waktu nyata. Tulisan ini melaporkan tentang hasil penelitian yang dilakukan tentang sistem computer vision yang dirancang untuk dapat mengenali gambar angka (0-9) dan operator matematika(penjumlahan (+) dan pengurangan (-)) pada permainan kartu angka. Sistem computer vision yang dirancang pada penelitian ini terdiri dari kamera pada ponsel android yang digunakan untuk menangkap gambar pada kartu angka dan komputer yang memiliki algoritama Jaringan Syaraf Tiruan Perceptron dalam melakukan identifikasi gambar. Kedua komponen sistem computer vision tersebut dihubungkan memlaui jaringan wireless melalui protocol TCP/IP. Pada tahapan pelatihan JST perceptron, digunakan 10 sample citra untuk masing – masing angka dan operator matematika yang akan dikenali oleh sistem. Pada penelitian ini juga dilakukan tahapan pemrosesan citra sebelum diolah oleh JST Perceptron baik dalam tahapan pelatihan maupun pada saat sistem dijalankan. Tahapan pengolahan citra yang digunakan pada penelitian ini adalah greyscalling, thresholding, cropping dan resizing. Hal ini dilakukan untuk menyaring informasi pada citra yang ditangkap oleh kamera agar didapatkan citra yang berukuran kecil dengan  informasi yang lengkap untuk diproses oleh JST Perceptron. Pada saat sistem diuji coba, diberikan 4 deret kartu angka di depan kamera. Pada pengujian pertama diberikan gambar angka 0-3, pengujian kedua diberikan gambar angka 4-7 dan pada pengujian ketiga diberikan angka 8-9 serta gambar operator penjumlahan dan pengurangan. Berdasarkan pengujian yang dilakukan, sistem computer vision yang dirancang mampu mengenali 10dari 12 gambar yang diberikan dengan tingkat keberhasilan sebesar 83.33%.</em></p><p><strong><em>Kata Kunci </em></strong><em>: computer vision, perceptron, kartu angka</em></p>

scholarly journals IMAGE PROCESSING METHOD BASED QUALITY TEST ON A SMART FLEXIBLE ASSEMBLY MECHATRONIC SYSTEM WITH COMPONENT RECOVERY

2020 ◽  
Vol 20 (4) ◽  
pp. 1037-1048
Author(s):  
MARIUS-ADRIAN PAUN ◽  
ION VALENTIN GURGU ◽  
OCTAVIAN GABRIEL DUCA ◽  
EUGENIA MINCA MINCA
Keyword(s):  
Image Processing ◽  
Vision System ◽  
Future Research ◽  
Mechatronic System ◽  
Quality Test ◽  
New Approach ◽  
Flexible Assembly ◽  
M Estimator ◽  
Processing Techniques ◽  
And Storage

. The article presents a new approach for image processing algorithms based on image processing techniques: edge detection, normal cross correlation (NCC) and M-estimator Sample Consensus (MASC). The new algorithm is integrated into the station dedicated to the quality test (QT) on a SMART flexible assembly mechatronic system with component recovery. As a result of the QT analysis, the manufacturing flow can continue with either the following operations: disassembly and recovery of components or transport and storage of good products. It is obvious the importance of implementing a high accuracy analysis function for products quality. The new algorithm increases the performance of the detection function both in terms of identification but also in the speed of QT execution. The results obtained in this article will be used in future research for the development of a machine vision system adapted to modern Industry 4.0 technologies, in which it will have the control structure specific to an integrated IoT sensor.

Uncertainty Evaluation of the Electrical Transient Rise Time

2021 ◽  
Author(s):  
Pedro O.C. Machado Neto ◽  
Keyword(s):  
Rise Time ◽  
Sampling Rate ◽  
Uncertainty Budget ◽  
Uncertainty Evaluation ◽  
Interpolation Function ◽  
Voltage Measurement ◽  
Expanded Uncertainty ◽  
Relative Contribution ◽  
Uncertainty Sources ◽  
The Impact

This paper deals with the uncertainty evaluation of the rise time of one pulse of an electrical fast transient burst (EFT/B), as carried out by the National Institute of Metrology, Quality and Technology (Inmetro) of Brazil. The main goal is to analyse the impact of two uncertainty sources not included in the uncertainty budget example in IEC 61000-4-4 standard, and not very well explored in the literature: Voltage Measurement and Horizontal Accuracy. The uncertainty sources considered in this evaluation were: the oscilloscope’s resolution and calibration of the voltage scale (Voltage Measurement) and the time scale (Horizontal Accuracy); the bandwidth of the measurement system; the oscilloscope sampling rate; and the repeatability of ten different measurements. Two sets of measurements were taken from two different oscilloscope settings: in the first one, the interpolation function was enabled, and in the other one was disabled. In both cases two components stood out for their huge relative contribution: time reading and repeatability. Considered together, these two components added up approximately 87% of the expanded uncertainty for interpolated samples, and 95% for non-interpolated samples. Also, the results indicate that the oscilloscope interpolation function (OIF), if available, should be used, as the expanded uncertainty decreases by 27% due to a better oscilloscope resolution. A discussion of the uncertainty budget example in Annex C of IEC 61000-4-4 is presented. In conclusion, once the OIF is enabled, the two additional uncertainty components discussed in this paper should be considered in the uncertainty budget. They should not be neglected since the combined relative contribution of these components is larger than the relative contribution of repeatability.

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