scholarly journals Spectral Characteristics of Rail Surface by Measuring the Growth of Rail Corrugation

2021 ◽  
Vol 11 (20) ◽  
pp. 9568
Author(s):  
Wootae Jeong

Continuous interaction between wheels and rails during train operation results in rail wear and tear. Corrugation of the rail surface is particularly caused by the contact mechanism between train wheel and rail and increases the vibration and dynamic wheel load, and if continued, leads to various defects and breakage of the track. Many devices are used to measure corrugation accurately, but measurement deviation varies greatly by measuring device. The most common corrugation measurement system measures surface roughness with a vibration acceleration sensor or displacement sensor. Corrugation with different pitches can be calculated by assuming the longitudinal rail surface as a chord with variable wavelength. Recent systems use a measurement model applying multiple sensors for more accurate measurement. This study investigated spectral characteristics of rail surface roughness based on long time measurement results. In particular, spectral changes upon the growth of rail surface wear and corrugation were analyzed when using the measurement system applying the chord offset method with multiple sensors. The results of analysis were verified through the field subway section, a running track undergoing corrugation, three months after initial measurement, and compared the measurement results according to the number of sensors. Additionally, the rail surface wavelength bands that affected measurement value according to the number of sensors were analyzed.

2019 ◽  
Vol 3 (2) ◽  
pp. 54-61
Author(s):  
Risse Entikaria Rachmanita ◽  
Haerul Ahmadi

Arduino UNO R3 is one of the cheapest and easiest microcontroller boards that has great potential to be used as a basis for the measurement system. This study aims to develop measurement system of crude oil capacitance by using IDCs(Interdigital Capacitors). By knowing the value of crude oil capacitance, the crude oil permittivity value can be calculated. The crude oil permittivity value data is extremely needed in making crude oil heating systems using microwaves. The study used IDC sprinted on a PCB board with a copper layer as the electrode. Then, the system measurement results were compared with the results of PM 6303 RCL meter Phillip type A frequency measurement of 1 kHz which was used as reference data to determine the extent of measurement errors. From the results obtained, it is known that the error value of the Arduino UNO R3 based capacitance repeatability measurement is 0.47%. While the results of the linearity test measurement of crude oil capacitance measurement of temperature increases using the Arduino Uno-based IDCs sensor, the R2 value is 0.87. Thus it can be seen that the Arduino UNO R3-based capacitance measuring device has quite good sensor characteristics.


Author(s):  
Tossenko O.M.

The development of measuring instruments requires a specialist to know the principles of operation of advanced measuring systems. This article describes guidelines for creating a virtual appliance in LabVIEW. LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is a graphical application programming environment used as a standard tool for measuring, analyzing their data, further ma­ naging devices and objects under study. LabVIEW language is not like other programming languages. It does not create a program, but a virtual tool, designed not only for the simulation of certain processes, but also for the management of hardware and the study of real physical objects. The article deals with the task of designing application software for a specific information-measuring device, analyzes the capabilities of the LabVIEW environment for spectral analysis of various signals, outlines the basic principles and techniques of programming within the framework of the LabVIEW graphical environment during the basic stages of development. The procedure for creating a virtual device is described, which allows to evaluate the spectral composition of the signals, presents a graphical code of execution (diagram) to the program and a graphical tool interface of the virtual device. A number of basic elements used to develop the program are described. The simplicity of the graphic designs, the ease of installation on the field of the program, the clarity and readability of the program — all of which makes LabVIEW preferred over other languages of programming. In most cases, the experiment is the only source of reliable information. And the result is achieved much faster than the methods of "pure" theory. The article substantiates the effectiveness of using a development tool that allows to obtain a software product and ensure the fulfillment of all the basic functions of an automated system. Developing a software algorithm for calculating statistical parameters will help engineering students understand the order of determining spectral characteristics and their place in the structure of experimental research.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1744
Author(s):  
Fernando Rodríguez Varela ◽  
Manuel José López Morales ◽  
Rubén Tena Sánchez ◽  
Alfonso Tomás Muriel Barrado ◽  
Elena de la Fuente González ◽  
...  

This paper introduces a near-field measurement system concept for the fast testing of linear arrays suited for mass production scenarios where a high number of nominally identical antennas needs to be measured. The proposed system can compute the radiation pattern, directivity and gain on the array plane, as well as the array complex feeding coefficients in a matter of seconds. The concept is based on a multi-probe antenna array arranged in a line which measures the near field of the antenna under test in its array plane. This linear measurement is postprocessed with state-of-the-art single-cut transformation techniques. To compensate the lack of full 3D information, a previous complete characterization of a “Gold Antenna” is performed. This antenna is nominally identical to the many ones that will be measured with the proposed system. Therefore, the data extracted from this full characterization can be used to complement the postprocessing steps of the single-cut measurements. An X-band 16-probe demonstrator of the proposed system is implemented and introduced in this paper, explaining all the details of its architecture and operation steps. Finally, some measurement results are given to compare the developed demonstrator with traditional anechoic measurements, and show the potential capabilities of the proposed concept to perform fast and reliable measurements.


2020 ◽  
Vol 26 (3) ◽  
pp. 469-483
Author(s):  
Nicholas W. M. Ritchie

AbstractThis is the first in a series of articles which present a new framework for computing the standard uncertainty in electron excited X-ray microanalysis measurements. This article will discuss the framework and apply it to a handful of simple, but useful, subcomponents of the larger problem. Subsequent articles will handle more complex aspects of the measurement model. The result will be a framework in which sophisticated and practical models of the uncertainty for real-world measurements. It will include many long overlooked contributions like surface roughness and coating thickness. The result provides more than just error bars for our measurements. It also provides a framework for measurement optimization and, ultimately, the development of an expert system to guide both the novice and expert to design more effective measurement protocols.


Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 560 ◽  
Author(s):  
Arkadiusz Kampczyk

In rail transport, measuring the actual condition of a circular curve of a railway track is a key element of track position monitoring not only during operation but also during final works. Predicting changes in its position in the horizontal plane is one of the most important related scientific issues. This paper presents the results of measurements performed with an innovative measuring device called the Magnetic-Measuring Square (MMS). The aim of the research was to demonstrate the acceptability of using the MMS. Horizontal versines of a rail track curve were measured as three neighboring points on a curve (using the method of lacing/stringlining, also called the three-point or the Hallade method), and the perpendicularity of rail joints and shortenings were measured. The MMS device presented in this article was used to measure versines and differences in rails lengths (rail shortenings in the curve) in the operating mode involving a laser distance meter with a laser beam (laser power P < 1 mW, laser wavelength λ = 635 nm) with a target cross, a camera, and a surveying measuring disk. The measurement results confirmed that it is possible to employ the MMS to monitor the geometry of railway track fragments such as track transition curves and railway track curves in rail transport.


2006 ◽  
Vol 321-323 ◽  
pp. 497-500
Author(s):  
Hak Joon Kim ◽  
Sung Jin Song ◽  
Lester W. Schmerr

For the proper interpretation of ultrasonic measurement results from a side-drilled hole (SDH) using a rectangular transducer, it is very helpful to have a complete ultrasonic measurement model. A highly efficient ultrasonic beam model of a rectangular transducer and an accurate scattering model of a SDH are currently available. However, to develop such a complete measurement model, a reference model for the system efficiency factor is also needed. In this study a reference model suitable for a rectangular transducer is given and combined with existing models to develop a complete ultrasonic measurement model that can the predict ultrasonic signals from a SDH. Based on this model, we have calculated the ultrasonic signals from a SDH at different transducer orientations and compared the model-based predictions with experiments.


2009 ◽  
Vol 59 (7) ◽  
pp. 1409-1413 ◽  
Author(s):  
T. Higuchi

Estimation of uncertainty in odour measurement is essential to the interpretation of the measurement results. The fundamental procedure for the estimation of measurement uncertainty comprises the specification of the measurement process, expression of the measurement model and all influences, evaluation of the standard uncertainty of each component, calculation of the combined standard uncertainty, determination of a coverage factor, calculation of the expanded uncertainty and reporting. Collaborative study such as interlaboratory comparison of olfactometry yields performance indicators of the measurement method including repeatability and reproducibility. Therefore, the use of collaborative test results for measurement uncertainty estimation according to ISO/TS 21748 and ISO 20988 is effective and reasonable. Measurement uncertainty of the triangular odour bag method was estimated using interlaboratory comparison data from 2003 to 2007 on the basis of the simplest model of statistical analysis, and the expanded uncertainty of odour index ranged between 3.1 and 6.7. On the basis of the establishment of the estimation procedure for uncertainty, a coherent interpretation method for the measurement results will be proposed and more effective and practical quality control of olfactometry will be available.


2015 ◽  
Vol 105 (06) ◽  
pp. 377-383
Author(s):  
F. Klocke ◽  
R. Brocker ◽  
F. Vits ◽  
P. Mattfeld

Beim Vibrationsgleitschleifen wird der Werkstoffabtrag maßgeblich durch die vorherrschenden Kontaktkräfte zwischen dem Werkstück und den Schleifkörpern bestimmt. Dieser Fachartikel stellt ein Messsystem vor, mit dem die messtechnische Erfassung der Kontaktkräfte beim ungeführten Vibrationsgleitschleifen möglich ist. Ein Alleinstellungsmerkmal ist dabei die vollständig kabellose Ausführung des Messsystems. Somit wurden die Messergebnisse nicht durch Kabel beeinflusst, die üblicherweise für die Energieversorgung und Datenübertragung notwendig sind. Mithilfe dieses Messsystems wurde der Einfluss folgender Prozesseingangsgrößen systematisch untersucht: Schleifkörpergröße, Unwuchtmotordrehzahl, Versatzwinkel der Unwuchtgewichte sowie die Masse des unteren und oberen Unwuchtgewichts auf die Kontaktkräfte. &nbsp; In vibratory finishing the material removal is influenced by the contact forces between work piece and media. In this paper a measurement system is presented which is able to measure contact forces between work piece and media in unguided vibratory finishing. The unique feature of the measurement system is its completely wireless construction so that the measurement results are not influenced by wires of the force sensor system including the electrical power supply and the data logging. By means of this measurement system, contact forces can be measured in unguided vibratory finishing processes for the first time. Furthermore, the influence of media size and adjustment of the unbalance motor like revolution speed, phase angle and mass distribution between the upper and the lower eccentric weight on the contact forces was investigated.


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