An Innovative Approach to Surveying the Geometry of Visibility Triangles at Railway Level Crossings

Railway level crossings (RLCs) in Poland are classified according to their protection systems. Category D, which is a form of passive RLC, aims to ensure safe and efficient operation. Surveying is essential to prepare and control the geometry of the visibility triangles used at RLCs. This article presents a new approach to monitoring the geometry of visibility triangles of RLCs using an electronic total station and a magnetic measuring square (MMS). Its main assumptions are presented together with the application of the innovative measuring instruments. Visibility is demonstrated taking into account the angles of intersection of the road axis with the track axis of the railway line and additional attributes related to the analysis and evaluation of general visibility conditions. The research highlights controversies that have received special attention against the background of the safety status of railway level crossings. As a case study, the RLC located on a single-track railway line in Poland is examined. The final section presents applications of the results obtained according to the proposed methodology. It is shown that the proposed approach is practical and effective. In addition to surveyors, the survey methodology can be used by road and rail traffic engineers and policy makers to further improve traffic safety at RLCs. This is an important global research task.

Measurement of the Geometric Center of a Turnout for the Safety of Railway Infrastructure Using MMS and Total Station

The turnouts in railway infrastructure constitute bottlenecks, limiting the capacity of the entire railway network. Due to their design and geometry, these turnouts force speed limits. The need to ensure the proper technical condition of turnouts has prompted ongoing scientific research and the use of modern technological solutions. Until now, there have been no tests for the correct location of the geometric center of a double and outside slip turnout with the related geometric relationships. Therefore, the main objective of this research was to demonstrate the position of the geometric centre of a double slip turnout and the geometric conditions of the curves of circular diverted tracks by measuring the horizontal versines and geometric irregularities of turnouts. The application of this surveying method, with reference to obtuse crossings and arising from geometric dependencies in the double and outside slip turnout, is defined and implemented (also known as a method for checking the correct location of the geometric center of a turnout—Surveying and Monitoring of the Geometric Center of a Double and Outside Slip Turnout (SMDOST)) via the Magnetic-Measuring Square (MMS) and electronic Total Station. This method also recommends measuring the horizontal versines of the diverted tracks. This paper presents the results of field measurements using the SMDOST and MMS methods, which were applied to carry out an analysis and evaluation of the turnout geometry conditions, thereby presenting the irregularities that cause turnout deformations. The validity of the SMDOST method using MMS and Total Station was thus confirmed. The observations from the conducted research indicate that neglecting measurements of the geometry of the turnouts resulted in additional irregularities in their conditions.

Magnetic-Measuring Square in the Measurement of the Circular Curve of Rail Transport Tracks

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.

Multiparametric quality by design-fuzzy model applied in the development of a biomedical measuring system

This work presents the adaptation of the Quality by Design (QbD) approach for application in the quality assurance of a biomedical measuring system under development. First attempts in applying QbD to biomedical technologies indicated a significantly higher number of parameters than its traditional application in the pharmaceutical industry. These preliminary studies did not fulfill the QbD stage of Design Space (DS) configuration for biomedical devices, an essential step to identifying the proper operating ranges of parameters and guaranteeing quality features. Therefore, it persisted the challenge of configuring DS for health devices, overcoming dependences in the interaction of multiple process parameters and critical attributes. The present work develops a hybrid QbD-Fuzzy approach for multiparametric DS configuration. The proposed method was applied in the development phase of a low-cost and high-sensitive magnetic measuring system for locating metallic foreign bodies in patients, employing sensors based on the Giant Magnetoimpedance effect. The results provided the acceptable operating ranges of the multiple process parameters to ensure the biomedical equipment's suitability. The proposed strategy contributes to the QbD implementation in biomedical technologies and, therefore, promotes the reliability of diagnostic and therapeutic results in the clinical environment.

Estimation of informative and background signals ratio in the registration of magnetic fields of surface defects by magnetic measuring transducers

Authors propose algorithms for quantitative ratio determining of informative and background components of the output signal of magnetic measuring transducers, used as a means of recording and measuring the parameters of locally distributed magnetic fields that occur over defective surface areas of the tested object in an applied permanent magnetic field. The method of separating the informative and background components based on the summation property and the deterministic nature of the distributions of the magnetic field intensity of the defect and the background magnetic field along the coordinate axis parallel to the controlled surface, and analysis of the topography of the distribution of magnetic field intensity is described. The approach to selection and experimental determination of estimated parameters characterizing the levels of informative and background signals is justified. Authors give the formulas for calculating the signal-to-background ratio based on the measured values of the estimated parameters applied to single magnet-static, differential magnet-static and differentiating magnetic measuring transducers taking into account the orientation direction (normal, tangential) of their sensitivity axis. The signal-to-background ratio calculation results are presented using an example of an analysis of the magnetic measuring transducers output signal when registering the distribution of the magnetic field intensity over the surface of a control sample with artificial defects of a given size. The comparative analysis of considered magnetic measuring transducers according to signal-to-background ratio is carried out. General recommendations to increase the value of the signal-to-background ratio parameter are given.

Measurement of the geometric conditions of the visibility of the level railroad crossing

The article discusses the issues related to the visibility conditions of level railroad crossing - taking into account the author's measurements. The results of the work on the geometric visibility conditions were obtained with the use of the manual adapters used to mount the geodetic prisms on the manual or digital gauges. The measurements also used a magnetic-measuring device with a disc. The technical and operational documentation of a railway / road crossing or passage, called the rail / road crossing / passage meter, requires geodetic and diagnostic work. Obligatory preparation of this documentation leads to improvement of its quality and uniformity throughout the country. The article presents author's observations and conclusions. This work was performed within the statutory audit of AGH US 11.11.150.005.