Investigation of the influence of the main error sources on the capacitive displacement measurements with cylindrical artefacts

2013 ◽  
Vol 37 (3) ◽  
pp. 721-737 ◽  
Author(s):  
Hichem Nouira ◽  
Alain Vissiere ◽  
Mohamed Damak ◽  
Jean-Marie David
Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1630
Author(s):  
Pablo Puerto ◽  
Beñat Estala ◽  
Alberto Mendikute

A laser triangulation system, which is composed of a camera and a laser, calculates distances between objects intersected by the laser plane. Even though there are commercial triangulation systems, developing a new system allows the design to be adapted to the needs, in addition to allowing dimensions or processing times to be optimized; however the disadvantage is that the real accuracy is not known. The aim of the research is to identify and discuss the relevance of the most significant error sources in laser triangulator systems, predicting their error contribution to the final joint measurement accuracy. Two main phases are considered in this study, namely the calibration and measurement processes. The main error sources are identified and characterized throughout both phases, and a synthetic error propagation methodology is proposed to study the measurement accuracy. As a novelty in uncertainty analysis, the present approach encompasses the covariances of correlated system variables, characterizing both phases for a laser triangulator. An experimental methodology is adopted to evaluate the measurement accuracy in a laser triangulator, comparing it with the values obtained with the synthetic error propagation methodology. The relevance of each error source is discussed, as well as the accuracy of the error propagation. A linearity value of 40 µm and maximum error of 0.6 mm are observed for a 100 mm measuring range, with the camera calibration phase being the main error contributor.


1988 ◽  
Vol 31 (2) ◽  
pp. 137-138
Author(s):  
A. D. Kuznetsov ◽  
E. V. Pashkevich ◽  
L. I. Golovenchits ◽  
N. K. Akkuratova
Keyword(s):  

2010 ◽  
Vol 148-149 ◽  
pp. 299-303
Author(s):  
Yue Peng Chen ◽  
Hong Wei Fu ◽  
Biao Wang

The paper presented a set of PRS-XY hybrid PMT, made up of a set of 3-PRS parallel mechanism and an X-Y table. For advancing the motion accuracy of the PRS-XY type hybrid CNC machine tool, the forward kinematics model and inverse kinematics model have been made, and main error sources affect to machine tool’s precision was established. The relative position of workpiece and the tool of PRS-XY PMT wad discussed, and the coordinate of tool surface was calculated in various process models. The chamfer shape with variation of main error sources was drawn in simulation software, and the processing experiment results prove the correctness of analysis and simulation.


1986 ◽  
Vol 109 ◽  
pp. 557-565 ◽  
Author(s):  
M. Miyamoto ◽  
M. Yoshizawa

In meridian observations, the main error sources of the declination observation reside in determination of the atmospheric refraction, the flexure of the telescope and the division errors of the graduated circle. In order to obtain higher accuracy in the declination observation, besides a full automation device, the photoelectric meridian circle at Tokyo Astronomical Observatory (Tokyo PMC) is equipped with photoelectric devices for circle reading and a zenith mirror in addition to the conventional mercury horizon. We report here on a preliminary determination of the horizontal and vertical flexures, and of the division errors of the glass circle.


2016 ◽  
Vol 8 (11) ◽  
pp. 937 ◽  
Author(s):  
Chao Ding ◽  
Guangcai Feng ◽  
Zhiwei Li ◽  
Xinjian Shan ◽  
Yanan Du ◽  
...  

2000 ◽  
Vol 44 (02) ◽  
pp. 120-139
Author(s):  
F. Lalli ◽  
F. Di Felice ◽  
P. G. Esposito ◽  
A. Moriconi ◽  
R. Piscopia

Some of the main error sources in wave pattern resistance determination were investigated. The experimental data obtained at the Italian Ship Model Basin (longitudinal wave cuts concerned with the steady motion of the Series 60 model and a hard-chine catamaran) were analyzed. It was found that, within the range of Froude numbers tested (0.225 ≤ Fr ≤ 0.345 for the Series 60 and 0.5 < Fr < 1 for the catamaran) two sources of uncertainty play a significant role: (i) the presence of a wave pattern generated by the air pressure disturbance, related to the carriage motion, and (ii) the unsteadiness of the free-surface flow (precision error). The importance of these effects increases, of course, with the model speed. The propagation of experimental errors in the wave resistance determination by the longitudinal cut method was next examined: within the elaboration of measured wave cuts experimental uncertainties are shown to be significantly damped. The wave resistance coefficient can be obtained therefore, with reasonable accuracy, from the measurement uncertainty point of view. Moreover, the errors related to wave cut truncation, as well as to probe transverse location, typical of the longitudinal cut method, were estimated. Systematic tests were performed by means of a numerical approach, which allows one to compare the wave resistance evaluated by the longitudinal cut method (applied in this case to the computed wave pattern) with the value obtained by pressure integration on the hull. As a result, the longitudinal cut method can be applied without introducing any severe limitation for the ratio b/L (tank width over model length), provided the wave cuts are measured at a proper transverse distance.


2013 ◽  
Vol 333-335 ◽  
pp. 207-214
Author(s):  
Si Yuan Lin ◽  
Ke Wang ◽  
Yue Chen Fan ◽  
Tao Yan ◽  
Neng He

The error of displacement measurements by digital image correlation method is examined from a pratical perspective. Different from previous research, this study focuses on external factors influencing the accuracy of displacement measurement in the study of cooperative mark recognition and camera placement. Our major objectives of this research include indentificating the chief error sources and assessing their influences on the testing results. There are 5 parts in this paper. We start with a brief introduction of the necessity of analyzing the errors. After reviewing the principles of digital image correlation method, an detailed discussion of error soureces of this method is provided. Then we design a pratical experiment measuring the characteristics of a spring vibrator using the digital image correlation mesurement systems and laser displacement sensor. By comparing the results from two ways of measurment, we end the study with the conclusion that the accuracy of displacement measuring by digital image correlation method is tightly related to the choice of cooperative mark and camera intersection angle.


2014 ◽  
Vol 621 ◽  
pp. 443-449
Author(s):  
Wen Xuan Liu ◽  
Hui Feng Wang ◽  
Guang Lin Wang ◽  
Dong Xiang Shao

This article analyzes the deviation of existing stiffness measurement method and comes to the main components of the measurement error. Focus on the influence of the bending deformation all of aspects and contact deformation between the various links to the measurement accuracy. Establish the relationship between the actual deformation and the measured deformation to the spring tube through homogeneous coordinate transformation and finite element analysis, in order to identify the error sources impact on the measurement greatest, and improve the measure methods to against the main error source, eliminate the influence of the main error source to the stiffness measurement, then achieve the purpose of improving the measure accuracy.


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