scholarly journals INDUCTION COUPLING BETWEEN JOINTLESS TRACK CIRCUITS AND TRACK-CIRCUIT-READER ANTENNA

2013 ◽  
Vol 138 ◽  
pp. 173-196 ◽  
Author(s):  
Linhai Zhao ◽  
Weishi Shi
Keyword(s):  
Reader Antenna ◽  
Track Circuits ◽  
Track Circuit

Clustering Algorithms for Direct Current Track Coded Signals

2019 ◽  
Author(s):  
Song Qin ◽  
Nenad Mijatovic ◽  
Jeffrey Fries ◽  
James Kiss
Keyword(s):  
Clustering Algorithm ◽  
Clustering Algorithms ◽  
High Availability ◽  
Digital Analysis ◽  
Signaling Systems ◽  
Track Circuits ◽  
Service Conditions ◽  
Track Circuit ◽  
Fail Safe

Designed for detecting train presence on tracks, track circuits must maintain a level of high availability for railway signaling systems. Due to the fail-safe nature of these critical devices, any failures will result in a declaration of occupancy in a section of track which restricts train movements. It is possible to automatically diagnose and, in some cases, predict the failures of track circuits by performing analytics on the track signals. In order to perform these analytics, we need to study the coded signals transmitted to and received from the track. However, these signals consist of heterogeneous pulses that are noisy for data analysis. Thus, we need techniques which will automatically group homogeneous pulses into similar groups. In this paper, we present data cleansing techniques which will cluster pulses based on digital analysis and machine learning. We report the results of our evaluation of clustering algorithms that improve the quality of analytic data. The data were captured under revenue service conditions operated by Alstom. For clustering algorithm, we used the k-means algorithm to cluster heterogeneous pulses. By tailoring the parameters for this algorithm, we can control the pulses of the cluster, allowing for further analysis of the track circuit signals in order to gain insight regarding its performance.

scholarly journals STUDY OF METHODS OF IMPROVING THE RELIABILITY OF THE INSTRUMENT IS FUNCTIONING TONAL TRACK CIRCUITS WHEN THE RESISTANCE OF THE BALLAST

2015 ◽  
Vol 1 (158) ◽  
Author(s):  
V. Sh. Khismatulin ◽  
V. Tikhonyuk
Keyword(s):  
Automatic Control ◽  
Control Systems ◽  
Output Voltage ◽  
Insulation Resistance ◽  
Automatic Control Systems ◽  
Track Circuits ◽  
Track Circuit ◽  
Further Development ◽  
Generator Output ◽  
Ballast Resistance

Based on the general principles of automatic control systems are considered options for the structureof tonal track circuit equipment with automatic correction tracking generator output voltage depending on the ballast resistance. For further development, a system of automatic control of the output voltage of thegenerator with the stabilization of its prescribed value. The prescribed value is set in accordance with the results of measurements of the insulation resistance (ballast).

scholarly journals Variability and uncertainty of Track Circuit band-pass modeling for interference evaluation

ACTA IMEKO ◽  
2013 ◽  
Vol 2 (1) ◽  
pp. 32
Author(s):  
Andrea Mariscotti
Keyword(s):  
Degrees Of Freedom ◽  
Evaluation Process ◽  
Rolling Stock ◽  
Definitive Answer ◽  
Normative Approach ◽  
The Status ◽  
Track Circuits ◽  
Band Pass ◽  
Track Circuit ◽  
Added Uncertainty

When evaluating track circuits (TC) interference, the latest normative approach indicates the use of band-pass filters that emulate the TC receiver response. The rms value of the output, when compared to the interference limit, indicates whether a specific signal might create interference or not. The implementation of the filter has some degrees of freedom and needs thus to be characterized in terms of added uncertainty to the interference evaluation process. The latter is relevant to safety, strictly related to the incorrect assignment of the status of the track section monitored and protected by the TC itself. When giving a definitive answer about the immunity of a specific TC and the compatibility with the tested rolling stock, it is thus necessary to completely evaluate the uncertainty associated to the chosen model and to the related signal processing operations, even if - it is recognized - their influence may be considered of second order with respect to infrastructure and rolling stock non-idealities.

scholarly journals Transient analysis on track circuits in crack state

2018 ◽  
Vol 173 ◽  
pp. 02046
Author(s):  
Zhao Bin
Keyword(s):  
Frequency Domain ◽  
Normal State ◽  
Traveling Wave ◽  
Transient Analysis ◽  
Complex Frequency ◽  
Track Circuits ◽  
Zero Moment ◽  
Track Circuit ◽  
Electro Magnetic ◽  
The Time Domain

The transient transformation of track circuit between the normal state and crack state is analyzed. Firstly, the model of crack state of track circuit in the complex frequency domain is established. According to the boundary conditions of crack state of track circuit, the expression of current traveling wave in the receiving end is obtained in complex frequency domain. Based on it, the numerical solution in the time domain is got by FFT&IFFT conjunction with quotient-difference (Q-D) algorithm. Then, the steady state of circuit in normal state is taken as state of zero moment of track circuit, the transient process from normal state transform into crack state is solved. Thirdly, the Electro-Magnetic Transient Program (EMTP) model of crack operation is established to prove that the transient analysis result is correct. It provides a power theoretical basis to distinguish the operation state of track circuit by transient analysis.

scholarly journals Mapping of the electromagnetic environment on the railway: Condition monitoring of signalling assets

2018 ◽  
Vol 234 (3) ◽  
pp. 246-256
Author(s):  
Alexander Knight-Percival ◽  
Christopher Johnson ◽  
Benjamin Richards ◽  
Scott Palmer ◽  
Nicholas Bowring
Keyword(s):  
Condition Monitoring ◽  
Detection System ◽  
Low Cost ◽  
Capital Outlay ◽  
Electromagnetic Environment ◽  
Analysis Techniques ◽  
Track Circuits ◽  
Condition Monitoring Systems ◽  
Advanced Analysis ◽  
Track Circuit

Conventional track circuit condition monitoring systems are fixed at the wayside, with each installation reporting on a single track circuit. In this work, we present a custom-built, sensitive, magnetic field detection system, which can be fitted to the underside of a rail vehicle. With this system installed, some characteristics of an operating track circuit can be monitored from the vehicle whilst it is in motion. By using appropriate analysis techniques, it is possible to identify the signatures of equipment relating to audio frequency track circuits, the topic of this work. Analysing the signatures of track circuit equipment demonstrated that there were clear differences between track circuit assets. By building on other research into the behaviours of failing track circuits, and continuing to conduct this research, the authors believe that it is possible, and beneficial, to perform condition monitoring of track circuits from low-cost equipment mounted on the train. Coupling this with advanced analysis techniques will allow predictive maintenance of track circuits with very little capital outlay.

A solution to transient failures of HVI track circuits caused by inrush interference based on wavelet analysis

2016 ◽  
Vol 231 (3) ◽  
pp. 359-369
Author(s):  
Zanwu Huang ◽  
Clive Roberts ◽  
Lei Chen ◽  
Shaobin Li ◽  
Hongguang Wang
Keyword(s):  
Fourier Transform ◽  
Control System ◽  
Wavelet Analysis ◽  
Failure Mode ◽  
Railway Systems ◽  
Wrong Side ◽  
Track Circuits ◽  
Inrush Currents ◽  
Track Circuit ◽  
Feature Frequency

A track circuit never reporting block failure means a track section is reported as vacant to a railway control system, even if it is occupied by a train. This is a wrong side failure which may cause an accident. A high-voltage impulse (HVI) track circuit based on the fast Fourier transform is currently in use in China to solve this problem, but it has been observed that when used in electric railway systems large inrush currents can lead to another track circuit failure mode, which is referred to as a transient reporting block (TRB) in this paper. The root causes and impact of TRB track circuit failures are analyzed and a solution to the TRB failure mode based on wavelet analysis is proposed. Computer simulations and onsite experiments are carried out and the results show that the proposed approach can accurately extract the feature frequency and then effectively avoid the TRB failure, even if the HVI track signal is disturbed by a significant inrush of traction-return current.

scholarly journals Elektromagnetiese modelle vir elektriese spoorbaanstelsels

1997 ◽  
Vol 16 (2) ◽  
pp. 86-95
Author(s):  
B. M. Steyn ◽  
J. D. Van Wyk
Keyword(s):  
Performance Analysis ◽  
Transmission Line ◽  
Current Distribution ◽  
Electromagnetic Interference ◽  
Railway Track ◽  
Traction Current ◽  
Different Types ◽  
Track Circuits ◽  
Track Circuit ◽  
Electromagnetic Models

The use of electromagnetic models is very expedient when railway track circuits are designed or when their operation is being studied. These electromagnetic models include models for performance analysis of the different types of track circuits as well as models used to study the effect of electromagnetic interference. Before these models can produce useful results they all require accurate input parameters. These parameters include the transmission line parameters of the track and the traction current distribution along the length of the track. Models that have been developed for these parameters are presented in this paper, together with an overview of the available track circuit models.

scholarly journals Reducing noise influence on an audio frequency track circuit

2019 ◽  
Vol 294 ◽  
pp. 03015
Author(s):  
Inna Saiapina ◽  
Mykhailo Babaiev ◽  
Olha Аnanіevа
Keyword(s):  
Electromagnetic Interference ◽  
Pulse Generator ◽  
Signal To Noise Ratio ◽  
Single Pulse ◽  
Audio Frequency ◽  
Railway Transport ◽  
Traction Current ◽  
Useful Signal ◽  
Track Circuits ◽  
Track Circuit

In connection with electromagnetic interference influence on the track circuits, the purpose of the research is finding the means to increase the noise immunity of an audio frequency track circuit. The authors propose a new engineering solution, which enables reducing the effect of noises on the input of the track receiver in the intervals between signal current pulses. The proposed noise-immune audio frequency track circuit is based on inserting a delay line, an adjustable single-pulse generator and a controlled electronic switch into the existing audio frequency track circuit equipment. To analyze its efficiency, the operation of the audio frequency track circuit was simulated under conditions of traction current disturbances, impulse and fluctuation interferences with the known parameters. The results show that proposed device for railway transport allows to increase a signal-to-noise ratio on the track receiver input from 8% to 30%, depending on the interference parameters and the level of the useful signal.

Risk Based Broken Rail Detection on Railways

2014 ◽  
Author(s):  
David F. Thurston
Keyword(s):  
Control Systems ◽  
Risk Mitigation ◽  
New Technology ◽  
General System ◽  
The United States ◽  
Practical Application ◽  
Train Control ◽  
Rail Systems ◽  
Track Circuits ◽  
Track Circuit

There has been a long debate among train control professionals related to broken rail detection; where it is required and how it is achieved. Despite this ongoing discussion, there has been little research in terms of the actual practical application of new technology or risk mitigation approaches since conventional track circuits have been applied to detect broken rails. This paper first looks at conventional broken rail detection as implemented with various track circuit types, then reviews the current research on alternate means of detection throughout the world. The paper will then quantify a risk based approach utilizing existing technologies to mitigate the broken rail requirements currently mandated for higher speed rail systems in the United States. Further, the implications for train control systems for both transit and the general system of railroads will be examined.

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