Rail Circuits Research Articles

Remaining useful life prediction method for jointless track circuits based on multivariate feature fusion and nonlinear Wiener process

Abstract Predicting the Remaining Useful Life (RUL) of track circuits is essential to ensure the safe and reliable operation of high-speed railways. In response to the challenges faced by current machine-learning-based RUL prediction methods, which struggle to represent the uncertainty in the probability distribution of RUL predictions, this paper suggests a hybrid-driven method for estimating remaining life. Firstly, the track circuit Health Index (HI) is constructed by feature dimensionality reduction and fusion of the original multivariate monitoring data through Kernel Principal Component Analysis (KPCA) and Autoencoder (AE); Secondly, the degraded state of the rail circuit is modelled using a nonlinear Wiener degradation model. Finally, the principle of First Hitting Time (FHT) is used to derive the Probability Density Function (PDF) of the anticipated RUL. The efficacy and superiority of the approach presented in this paper are validated by experimental research on the track circuit monitoring dataset. The method enhances forecast accuracy and reduces prediction uncertainty, offering robust technical support for track circuit maintenance decision-making.

TRACK CIRCUITS INTERFERENCE RESISTANCE INCREASE UNDER THE TRACTION CURRENT INFLUENCE

Purpose. The aim of the work is to increase the electromagnetic compatibility of track circuits with the traction power supply system of railways under the influence of reverse traction current disturbances. Conducting research and analysis of the causes of malfunctions of rail circuits on electrified sections of the railway, existing means and methods of increasing the interference resistance of track circuits and ensuring the electromagnetic compatibility of signaling, centralization and blocking devices with the traction power supply system, and the development of effective technical solutions for normalizing the operation and rail circuits in the conditions influence of traction current interference. Conducting a study of the electromagnetic characteristics of the DT-1-150 track choke-transformer in normal mode and under the influence of external factors on the magnetic system. Methods. During the research, methods of comparative analysis, theories of electric and magnetic circuits, methods of spectral analysis of signals, as well as mathematical, schematic and physical modeling were used. Findings. Situations in which the traction current significantly affects the operation of the rail wheel equipment have been analyzed in the work. The effect of the traction current constant component on the normal operation mode of the track circuits is considered. The coefficients value of the choke-transformer DT-1-150 with traction current asymmetry was determined. A comparative analysis of resistance to reverse traction current disturbances of track receivers of station rail wheels used at the docking station was conducted. The principle-structural scheme of the protective unit for blocking the leakage of direct traction current interference on the section of alternating current traction was developed. The scientific novelty. The scientific novelty of the work consists in identifying and justifying the causes of some specific failures of track circuit; in confirming the integral effect of choke-transformer steel core saturation, created by the constant component of the traction current in the railway power supply system. Practical significance. Based on the conducted research, the interference resistance of the 25 Hz track circuit with the DSSH-16 track relay and DT-06-500S was confirmed. A protective valve block was developed, which prevents the flow of the first periods of the largest amplitude transient current in the track circuit its protects and ensures, thereby, normal operation of track circuit.

Creation of a Mathematical Model of a Stationary Rail Circuit in the Form of a Finite Discrete Automaton

Purpose. Ensuring the safety of train traffic is a mandatory task in the development of technical equipment of railway transport in Ukraine. To diagnose and verify the performance of such systems, simulation models of overhead devices, in particular, the rail circle, are used. The most commonly used models are in the form of differential equations and in operator form. Unfortunately, they are not fully suitable for solving this problem. In this regard, there is a need to create a mathematical model that is easier to integrate for checking both relay electrical interlocking and microprocessor-based interlocking systems. Methodology. To achieve this goal, the authors proposed to create a mathematical model in the form of a finite discrete automaton. This paper considers the creation of a model of a station rail circuit as a directed graph. During the creation of the model, the input and output values of the model and the states are determined. The tables of inputs and outputs of the automaton are constructed, sequential expressions for the abstract model of the automaton are created, and their minimization is performed. The states of the automaton are coded using trigger circuits. Findings. In the course of the research, a mathematical model of the rail circle in the form of a Moore model finite automaton was created, and its performance was tested in the Proteus software environment. The developed model allows to simulate the operation of a stationary rail circuit at the level of abstraction, which operates with binary signals. This makes it possible to simplify the coordination of the model with microprocessor-based centralization software. In general, it is now possible to more effectively check the performance of microprocessor-based interlocking systems at the design and commissioning stages. Originality. The developed mathematical model makes it possible to determine the response of the microprocessor-based centralization software to the behavior of the rail circuit in various, in particular atypical, operating modes, as well as to determine the response of the station electrical centralization system to individual failures and to the occurrence of several failures simultaneously. Practical value. The proposed mathematical model can be used both to check the operation of microprocessor-based centralization systems at the design and implementation stages and for relay centralization systems when developing diagnostic complexes for monitoring their performance.

Statement of the problem of selecting and justifying the technical and operational characteristics of rail circuits on high-speed rail transport

Statement of the problem of selecting and justifying the technical and operational characteristics of rail circuits on high-speed rail transport

Математическое моделирование дополнительной зоны шунтирования в рельсовых цепях с потенциальным приемником: алгоритм и расчеты

The paper presents an algorithm and methodology for calculating the additional shunt zone in track circuits with a potential receiver. The issues of mathematical modeing of a seamless track circuit are considered, and a method is proposed for determining the maximum shunting zone when the train moves away from the track circuit. The calculation results make it possible to conduct research and determine the optimal parameters of rail circuits with a potential receiver, which is important for taking technical easures to improve the operation of transport systems.

Экспертная система для диагностики неисправности рельсовой цепи с использованием искусственного интеллекта

The paper presents an algorithm and programs for an expert system designed to determine the failure of a rail circuit in railway transport. Mathematical and simulation models have been studied to determine the operating modes of a rail circuit with current collection. Algorithms and programs have been developed to create expert systems based on these models, which allows to quickly diagnose faults and provide recommendations for their elimination.

Urban Rail System Modeling and Simulation Based on Dynamic Train Density

To further improve the simulation calculation ability of urban rail traction systems during the peak operation period and provide an accurate and reliable simulation tool for the subsequent train schedule and energy storage system design, a multi-train circuit model with a bilateral power supply was established in this paper, and a power calculation algorithm based on dynamic train density was designed. The circuit topology in the model can be dynamically adjusted according to the number of trains to improve the operation rate. Based on the spatial and electrical data of a real section of the subway, the urban rail circuit model was built on the MATLAB platform, and the actual operation data of the subway was imported for verification. The experimental results show that the multi-train model can accurately reflect the influence of voltage fluctuations on the traction system under different train running conditions, and the results fit the actual operation conditions. By comparing the influence of different train intervals on the RBE (regenerative braking energy) utilization, the results show that the optimal RBE utilization rate can be achieved by adjusting the train interval in the peak period.

Mathematical models and algorithms for determining the modes of an intelligent stage control sensor

In article discusses models of unlimited track circuits with a receiver, adapting to different working conditions, applied double receiver with one power supply in the middle, which allows you to extend the length of the continuous rail circuit. For this, a goal is set, in which is the development of models of jointless track circuits with an adaptive receiver, in which the rail line must take into account the total stress distribution along the rail line and disturbing factors. The article presents the equivalent circuits of continuous welded rail circuits with an adaptive receiver, algorithmic expressions for determining currents and voltages at the ends of the rail circuit, the coefficients of rail lines with an adaptive receiver are developed, calculation algorithms are presented. In conclusion, a graph is given, according to which it is shown that a continuous rail circuit with an adaptive receiver can operate with an insulation resistance three times lower than the threshold value in any modes of the rail circuit, taking into account the fact that, minimum allowable insulation resistance for tone-on-tone continuous rail circuits is taken as Ri=0,7ohm*km. Derived for the theory and synthesis of solutions, and also proposed new approaches to ensure the operating modes of the rail circuit, taking into account the real and weather conditions of operation.

Analysis of research on smart rail circuits

The purpose of the article is to study intelligent continuous-type rail circuits with current receivers, respectively, to identify the possibility of determining the unit located on the rail lines with a standard shunt prescribed in the operating rules, as well as monitoring for breakage of a continuoustype rail circuit. To study smart railway circuits, it is necessary to take into account the circuit diagram of this track circuit and its operation with various factors influencing it. One of the points of the study is to determine the maximum and minimum resistance at the beginning and at the end of this rail line and also taking into account the worst influencing parameters on an intelligent rail circuit of unlimited length, carry out calculations and determine on the graphs the probability of failure-free operation in all modes. The study took into account fluctuations in temperature decline, both during the seasons, winter, summer, etc., and sharp continental changes within an hour in operating mode. When conducting the study, we also took into account the insulating resistance that affects the power supply of the composition determination sensor, which leads to a dependence on the length of the smart sensor. The parameters of changes in the sensor supply voltage, its variability from the supplier and the resistance of the rails and their fluctuations were taken. For this purpose, the requirements for the length of the intelligent rail circuit, shunt resistance and insulation resistance used on the road were applied, as well as determining the influence of all unfavorable conditions.

MATHEMATICAL MODELING OF THE OPERATION OF AUDIO FREQUENCY (NO JUNCTION) AND JUNCTION RAIL CIRCUITS

Rail circuits are the basic elements of modern railway automation and telemechanics systems, performing the functions of track sensors and telemechanical channels. It is shown that the calculation of their operating boundary conditions becomes more complicated with the application of junctionless audio frequency rail circuits. The analysis of track circuits consists of studying the changes in their operation in various modes when the circuit parameters are changed. During the analysis, the optimal values of the parameters of the circuit elements and the frequency of the power source are determined for the given operating conditions. An analysis of the factors affecting the operating currents and voltages of such rail circuit schemes has been carried out. When analyzing and calculating a track circuit, it is assumed that the track line and equipment elements are linear, that is, their parameters do not depend on the flowing currents. To simplify the calculations, the track circuit is represented by the corresponding mathematical model (equivalent circuit) for each mode. Depending on the type of equivalent circuit used, four-pole and multi-pole models are distinguished. At the same time, the analysis and reporting of jointed rail circuits are carried out. Based on their results, the directions that allow for more accurate modeling of the operating modes of the circuits of the non-joint audio frequency rail circuits have been determined. Keywords: Rail circuits, train traffic safety, audio frequency (no junction) track circuits, junction rail circuits, signaling system, track sensors, mathematical model, remote conditioning monitoring.

Алгоритмы принятия решений для автоматизированного выполнения и планирования работ по проверке рельсовых цепей на шунтовую чувствительность

The article considers the issues of practical application of the approach on performance automation and scheduling of works on the maintenance of railway automatics and remote controlling devices in the process of planned preventive maintenance realization which includes the analysis of known ways to automate railway circuit inspections on shunt sensitivity and shunt effect performance control in the process of finding a moving unit on a rail circuit. At present, topical problem is the reduction of labor costs on the maintenance of dispersed objects of automatics and remote control which to solve for, we propose to use algorithms providing for technological situation identification and determination of the many of works which will be considered automatically as accomplished as well as the many of ones which will be needed to be accomplished in due time. The essence of the proposed approach to automation of being considered processes is in the following: if in the process of rail circuit functioning in regular mode, the situation, that’s analogous to the performance of work on shunt sensitivity testing (that’s stipulated by work operation technology), is realized, then work is considered to be accomplished at the presence of means of reliable control for the values of rail circuit parameters.

КОНТРОЛЬ ЦЕЛОСТНОСТИ РЕЛЬСОВЫХ НИТЕЙ ПРОТЕКАЮЩИМ ТОКОМ

Violations of the integrity of rails on railway sections pose a serious threat to traffic safety, cause accidents and wrecks, lead to significant economic damage and human casualties. The integrity of rails is controlled by flaw detection methods, as well as by a special mode of operation of rail circuits due to the signal current flow around track circuits. The widespread use of AC rail circuits which reliably perform the control mode made it possible to organize a simple method of integrity control over a significant length of railway lines. The complexity of maintenance and low reliability of track circuits, in turn, led to emergence of alternative technical solutions for monitoring the vacancy of railway sections. However, these solutions are not able to control the integrity of rails and prevent elimination of track circuits. On the other hand, the joint use of continuous monitoring of rails and low-maintenance solutions for monitoring the vacancy of track sections will ensure reduction in operating costs with a constant level of traffic safety. The article analyzes technical solutions for monitoring the integrity of rails due to continuous current flow. The maximum length of the contour formed by two rails is set to control the integrity of the rails. The prospects of solutions for monitoring the integrity of rails based on the electrical circuit formed by rails and a cable running along them are shown.

Insulating joints as a destabilizing factor in the operation of the track circuit

The role of railway transport in the modern economy is highlighted in the article. Directions for improving automation and telemechanics devices have been determined: the creation and implementation of modern devices for monitoring track occupancy of a new type, as well as increasing the reliability of track devices to a large extent, and putting into operation systems for interval regulation of train traffic. The importance of such an element of the railway infrastructure as a rail circuit is also determined. The authors of the work revealed the function of track circuits. In addition to this, the article presents an information diagram of the search for failures in an extensive rail circuit of electrical centralization. The concept of a decision device is disclosed. Possible expressions of the Bayes criterion are also considered. A priori probabilities of finding rail lines are singled out. As a result, a decision rule is revealed that leads to the minimization of the average damage.

Research on the Armature–Rail Dynamic Contact Characteristics of the Series Enhanced Electromagnetic Rail Launcher

To study the dynamic contact characteristics of the armature–rail of the series-enhanced electromagnetic rail launcher, the electrical connection of the launcher is divided into an armature circuit, an arc suppression circuit, and a vice rail circuit to construct an effective electrical model that considers the actual motion of the armature. The mathematical relationship model of the armature–rail contact resistance and outlet voltage, rail current, armature speed–displacement, and device parameters (inductance gradient, resistance gradient, mutual inductance gradient) and other physical quantities is obtained, and the change curve of the contact resistance of the armature–rail is measured through experiments and finite element/boundary element simulation calculations. The results show that the contact state of the armature–rail can be divided into three stages by the change curve, which is consistent with the rail damage state obtained by the actual measurement. The work done in this article can provide an effective reference for predicting the rail damage and armature thermal load design of the series-enhanced electromagnetic rail launcher.

MODEL OF A RAIL LINE WITH DISCRETELY DISTRIBUTED PARAMETERS

The article provides equivalent circuits for an adaptive rail circuit with discrete-distributed parameters and offers its mathematical model.

Analysis, development of a model and an algorithm in the concept of the growth of tone jointless rail circuits

An increasing increase in freight and passenger traffic, as well as an increase in train speeds, which reach up to 350 km/h, sets the task of improving sensors for controlling track sections and ensuring the reliability in work of the sensors. Throughout the world, one of the sensors are track circuits, as with insulating joints, so and without insulating joints. To realize a more reliable system, intelligent track circuits are proposed based on a jointless voice frequency connections, in which different principles can be used: regulation of the power supply voltage, correlation methods for switching on rail lines and devices of rail circuits with electromagnetic dependences, receiver sensitivity adjustment, comparison of electrical parameters of several track circuits at different block sections, as well as the combination of these methods and the continuity of the incoming information. Therefore, such improvement of continuous welded rail circuits becomes relevant, which would improve the reliability of the elements, use a modern microprocessor element base in devices for monitoring the state of track sections, thereby ensure the quality of synthesis of information processing. This will significantly reduce the cost of building and operating interval control systems and increase the safety of train traffic. These requirements are met by intelligent, jointless rail circuits of tone frequency, which take into account the current value of the insulation resistance, longitudinal asymmetry, rate of change in the resistances of these circuits and the disturbing factors that affect the operation of the track circuits.

Methods calculation for station tonal rail circuits with current receiver

At present, at stations, for controlling station sector mainly applied phase-sensitive and tonal track circuits with insulating joints. One of the disadvantages of currently used tonal track circuits without insulating joints is that when the train approaches the controlled section, train begins to shunt this section at some distance before entry on it. This distance depends on many variables and constantly changes depending on these variables. To eliminate this drawback, it is proposed to use a current track receiver instead of the traditional potential receiver, which has a clear boundary for fixing the train entrance to the controlled section. By the present time, methods have been developed and are used to determine the main analytical expressions for the analysis and synthesis of tonal track circuits with potential receivers in various modes of operation, and the theoretical issues of tonal track circuits with current receivers were practically not considered, in this connection, the article discusses the development of mathematical models for determining the absolute shunt sensitivity of tonal track circuits without insulating joints with current receivers and calculation methods for determining the critical point of minimum shunt sensitivity. The obtained expressions differ from the well-known equations of absolute shunt sensitivity and the critical point of the minimum value of shunt sensitivity and will allow for analysis, synthesis and design of tonal track circuits without insulating joints with current receivers, which will increase the safety of train traffic.

METHOD DETERMINATION OF THE SENSORS CONTROL OF CONDITION TRACK SECTION WITH AN ADAPTIVE RECEIVER

The article presents one of the most promising methods for detecting a moving unit by a sensor for monitoring the condition of track sections, namely, rail circuits with an adaptive receiver. The scheme for realizing control sections using a computer is presented.

Mathematical model of the sensor for controling the condition of the track section with an adaptive receiver at the free condition of the controlled section

One of the promising areas of improvement of sensors for monitoring the condition of track sections is the development of controlling sensors, which are less dependent on changes in ballast resistance, longitudinal asymmetry and standard value of shunt sensitivity, such a direction is the development of adaptive track circuits [1-5]. The article proposes a control sensor with an adaptive receiver, principle of operation of which is that monitoring the state of the track section depends on the parameters of adjacent monitoring sensors, included in the common controlled zone CZ.Mathematical model and analytical expressions have been developed taking into account the resistance of the rails and the resistance of the insulation being carried out [6]. Proposed the coefficients of a rail fourpole with one of the choke-transformer, powered with one side. The calculated expressions of the fourpole and the criteria for the sensitivity of the rail circuit when one line is broken are presented and derived, and also the minimum transmission resistance [6].

Synthesis of a device for anti-jamming reception of signals of tonal rail circuits on the background of additive five-component interference

An optimal receiving device for information signals of tonal rail circuits has been synthesized. The signals are observed against the background of an additive five-component interference. The first component of the interference is broadband Gaussian noise. The other four components of the interference are structurally determined: single impulse interference, interference from an adjacent tonal rail circuit, and multiharmonic interference from alternating traction current combined with the power line and from the locomotive traction converter. The presence of a complex of interference leads to errors in decision-making regarding the regulation of train traffic. This puts the participants in this movement before the danger of threatening emergencies. Therefore, it is necessary to develop and study means of noise-immune reception of information signals and the formation of dispatch decisions. The decision on the presence or absence of a signal is made by comparing two values of the mean square of the approximation error. This error is understood as the difference between the input voltage of the receiver and the sum of the signal with structurally determined interference. The first value of the error is calculated assuming the presence of a signal in a mixture with structurally determined noise. The second error value is calculated on the assumption that there is no signal in this mixture. The noise component is assumed to be present in both cases. The solution corresponds to a channel with a lower mean squared error. The block diagram of the device is presented. Analytically, it has been shown that the average value of the error in recognizing situations of presence or absence of a signal is two orders of magnitude less than the admissible value according to regulatory requirements. High noise immunity of the developed device will improve the safety of train traffic