Uncertainty Estimation for the Optical System of Optical Measuring Machines

This paper presents the problem of optical measuring machine calibration, emphasizing the calibration of the "optical system", omitting the calibration of the "machine system". The calibration of an optical measuring machine is the first step before using the instrument for any application. For this purpose, a mathematical model has been developed to transform the coordinates of a point in space (3D) into coordinates of a point in an image (2D). Using this camera model, a calibration procedure has been developed using a grid distortion pattern. Finally, a procedure for calculating the uncertainty of the camera and geometric distortion parameters based on the Monte Carlo method has been developed.

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Proposed New AV-Type Test-Bed for Accurate and Reliable Fish-Eye Lens Camera Self-Calibration

Sensors ◽

10.3390/s21082776 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2776

Author(s):

Kang Hyeok Choi ◽

Changjae Kim

Keyword(s):

Outer Part ◽

Calibration Procedure ◽

Geometric Distortion ◽

Eye Lens ◽

Wide Field ◽

Test Bed ◽

Self Calibration ◽

Type Test ◽

Balanced Distribution ◽

Fish Eye

The fish-eye lens camera has a wide field of view that makes it effective for various applications and sensor systems. However, it incurs strong geometric distortion in the image due to compressive recording of the outer part of the image. Such distortion must be interpreted accurately through a self-calibration procedure. This paper proposes a new type of test-bed (the AV-type test-bed) that can effect a balanced distribution of image points and a low level of correlation between orientation parameters. The effectiveness of the proposed test-bed in the process of camera self-calibration was verified through the analysis of experimental results from both a simulation and real datasets. In the simulation experiments, the self-calibration procedures were performed using the proposed test-bed, four different projection models, and five different datasets. For all of the cases, the Root Mean Square residuals (RMS-residuals) of the experiments were lower than one-half pixel. The real experiments, meanwhile, were carried out using two different cameras and five different datasets. These results showed high levels of calibration accuracy (i.e., lower than the minimum value of RMS-residuals: 0.39 pixels). Based on the above analyses, we were able to verify the effectiveness of the proposed AV-type test-bed in the process of camera self-calibration.

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Measurement Uncertainty Estimation for Laser Doppler Anemometer

Energies ◽

10.3390/en14133847 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3847

Author(s):

Karolina Weremijewicz ◽

Andrzej Gajewski

Keyword(s):

Power Plants ◽

Thermal Power ◽

Regression Line ◽

Estimation Algorithm ◽

Calibration Procedure ◽

Uncertainty Estimation ◽

Two Phase ◽

Mass And Heat Transfer ◽

Preliminary Study ◽

Measurement Uncertainty Estimation

Twenty percent of global electricity supplied to the buildings is used for preventing air temperature increase; its consumption for this prevention will triple by 2050 up to China’s present needs. Heat removed from the thermal power plants may drive cold generation in the absorption devices where mass and heat transfer are two-phase phenomena; hence liquid film break-up into the rivulets is extensively investigated, which needs knowledge of the velocity profiles. Laminar flow in a pipe is used in the preliminary study, velocity profile of developed flow is used as a benchmark. The study account writes the applied apparatus with their calibration procedure, and the uncertainty estimation algorithm. The calibration regression line with the slope close to one and a high Pearson’s coefficient value is the final outcome. Therefore, the apparatus may be applied in the principal research.

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Articulated Arm Coordinate Measuring Machine Calibration by Laser Tracker Multilateration

The Scientific World JOURNAL ◽

10.1155/2014/681853 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11 ◽

Cited By ~ 32

Author(s):

Jorge Santolaria ◽

Ana C. Majarena ◽

David Samper ◽

Agustín Brau ◽

Jesús Velázquez

Keyword(s):

Coordinate Measuring Machine ◽

Spatial Localization ◽

Model Parameters ◽

Nominal Data ◽

Identification Procedure ◽

Calibration Algorithm ◽

Measuring Machine ◽

Euclidean Distances ◽

Machine Calibration ◽

Nonlinear Optimization Algorithm

A new procedure for the calibration of an articulated arm coordinate measuring machine (AACMM) is presented in this paper. First, a self-calibration algorithm of four laser trackers (LTs) is developed. The spatial localization of a retroreflector target, placed in different positions within the workspace, is determined by means of a geometric multilateration system constructed from the four LTs. Next, a nonlinear optimization algorithm for the identification procedure of the AACMM is explained. An objective function based on Euclidean distances and standard deviations is developed. This function is obtained from the captured nominal data (given by the LTs used as a gauge instrument) and the data obtained by the AACMM and compares the measured and calculated coordinates of the target to obtain the identified model parameters that minimize this difference. Finally, results show that the procedure presented, using the measurements of the LTs as a gauge instrument, is very effective by improving the AACMM precision.

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Camera Model and Calibration Procedure for Oblique-Viewing Endoscope

Lecture Notes in Computer Science - Medical Image Computing and Computer-Assisted Intervention - MICCAI 2003 ◽

10.1007/978-3-540-39903-2_46 ◽

2003 ◽

pp. 373-381 ◽

Cited By ~ 9

Author(s):

Tetsuzo Yamaguchi ◽

Masahiko Nakamoto ◽

Yoshinobu Sato ◽

Yoshikazu Nakajima ◽

Kozo Konishi ◽

...

Keyword(s):

Calibration Procedure ◽

Camera Model

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A Simplified Software for Uncertainty Estimation Using Monte Carlo Method

Advanced Science Engineering and Medicine ◽

10.1166/asem.2020.2667 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1050-1053

Author(s):

Jasveer Singh ◽

L. A. Kumaraswamidhas ◽

Neha Bura ◽

Kapil Kaushik ◽

Nita Dilawar Sharma

Keyword(s):

Monte Carlo ◽

Standard Deviation ◽

Monte Carlo Method ◽

Measurement Uncertainty ◽

Standard Uncertainty ◽

Uncertainty Estimation ◽

End Points ◽

The Monte Carlo Method ◽

Adaptive Trials ◽

Coverage Interval

The current paper discusses about the application of Monte Carlo method for the evaluation of measurement uncertainty using in-house developed program on C++ platform. The Monte Carlo method can be carried out by fixed trials as well as adaptive trials using this program. The program provides the four parameters viz. estimate of measurand, standard uncertainty in the form of standard deviation and end points of coverage interval as an output.

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Adjustable-tip internal horseshoe gauges for a horizontal optical measuring machine

Measurement Techniques ◽

10.1007/bf00822336 ◽

1976 ◽

Vol 19 (9) ◽

pp. 1369-1370

Author(s):

V. M. Sterzhakov ◽

I. M. Shcherbakov

Keyword(s):

Optical Measuring ◽

Measuring Machine

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Calibrator for 2D Grid Plate Using Imaging Coordinate Measuring Machine with Laser Interferometers

International Journal of Automation Technology ◽

10.20965/ijat.2015.p0541 ◽

2015 ◽

Vol 9 (5) ◽

pp. 541-545 ◽

Cited By ~ 2

Author(s):

Mariko Kajima ◽

◽

Tsukasa Watanabe ◽

Makoto Abe ◽

Toshiyuki Takatsuji

Keyword(s):

Measurement Method ◽

Laser Interferometer ◽

Coordinate Measuring Machine ◽

Calibration Procedure ◽

Expanded Uncertainty ◽

Geometrical Error ◽

Grid Plate ◽

Measuring Machine ◽

Laser Interferometers

A calibrator for 2D grid plates have been developed. The calibrator was based on a commercial imaging coordinate measuring machine (imaging CMM). A laser interferometer for the calibration of the x-coordinate and two laser interferometers for the calibration of the y-coordinate were attached to the imaging CMM. By applying multistep measurement method for the calibration procedure, the geometrical error in the calibrator was reduced. The calibration of a precision 2D grid plate was demonstrated, and the expanded uncertainty was estimated to be 0.2 μm (k =2).

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RATIONAL RADIAL DISTORTION MODELS OF CAMERA LENSES WITH ANALYTICAL SOLUTION FOR DISTORTION CORRECTION

International Journal of Information Acquisition ◽

10.1142/s0219878904000173 ◽

2004 ◽

Vol 01 (02) ◽

pp. 135-147 ◽

Cited By ~ 18

Author(s):

LILI MA ◽

YANGQUAN CHEN ◽

KEVIN L. MOORE

Keyword(s):

Analytical Solution ◽

Polynomial Approximation ◽

Distortion Correction ◽

Camera Model ◽

Distortion Model ◽

Radial Distortion ◽

New Class ◽

Comparable Accuracy ◽

The Common ◽

Distortion Parameters

The common approach to radial distortion is by the means of polynomial approximation, which introduces distortion-specific parameters into the camera model and requires estimation of these distortion parameters. The task of estimating radial distortion is to find a radial distortion model that allows easy undistortion as well as satisfactory accuracy. This paper presents a new class of rational radial distortion models with easy analytical undistortion formulae. Experimental results are presented to show that with this class of rational radial distortion models, satisfactory and comparable accuracy can be achieved.

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UNCERTAINTY ESTIMATION OF CONSTRUCTED METROLOGY FRAME

International Journal Advanced Quality ◽

10.25137/ijaq.n2.v45.y2017.p37-42 ◽

2017 ◽

Vol 45 (2) ◽

pp. 37

Author(s):

Ryoshu Furutani

Keyword(s):

Uncertainty Estimation ◽

New Method ◽

Displacement Sensor ◽

Profile Error ◽

Measuring Machine ◽

Profile Errors

In general, the profile measuring machine uses the displacement sensor attached on movable mechanism in order to measure the object. It could measure the object profile by the amount of movement of the displacement sensor and output of the displacement sensor. When measuring the object, metrological frame is important as a reference. If the metrological frame has some profile errors, the output of the displacement sensor includes the profile error of the metrological frame. We proposed a new method to distinguish the profile error of the metrological frame from the output of the displacement sensor. This method requires two linear stages and a displacement sensor. The object profile and profile error of the movable mechanism are determined by calculation using output of the displacement sensor. The validity of the new method was confirmed by the simulation andexperiment. It was confirmed to be possible to construct metrological frame below 1μm. As a lot of number of iteration are required, the reduction of iteration was discussed. As a result of reduction of measurement, the uncertainties of measurement are shown and compared.

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