Railway Signalling Research Articles

Homogenous and interoperable signaling computer interlocking through IEC 61499 standard

The technological evolution of signaling systems has created a dependency from infrastructure managers to suppliers and industrials dominating the market. Indeed, for each deployed computer interlocking, the modification of field equipment is required to allow an adaptation with the new interlocking in terms of communication protocols and logical interface. In addition, to ensure safe traffic of trains, the communication of railway signaling data is necessary between interlockings. However, delayed deployments from one station to another make the establishment of communication channels costly and difficult, or even impossible, since each supplier keeps confidential its communication protocols and usually opts for interfacing based on wired logic. This paper presents our approach to a homogeneous architecture of interlocking meeting modularity requirements, interoperability, and logical interfacing between interlockings. This approach relies on a classification of internal functions of the computer interlocking, a distribution of the execution of those functions and making useful information available for interfaces between adjacent interlockings through the IEC 61499 standard coupled with service-oriented architecture (SOA).

Risk Assessment in the Design of Railroad Control Command and Signaling Devices Using Fuzzy Sets

Risk assessment in the design of control command and signaling devices (CCS) is one of the elements required by law. These analyses should be carried out at many stages of investment with the participation of various teams. This article presents a risk analysis method based on fuzzy sets, which can support and increase the safety of investment processes involving the railroad traffic control industry. The article analyzes hazards identified in CCS design. These risks were identified using a survey method based on a set of questions prepared by the authors and by conducting interviews among experts from design offices. As part of the survey, responses were obtained from 28 respondents who are specialists in the railway traffic control industry. Workshop meetings were held in six different design offices and at manufacturing plants of motion control systems. The identified risks were analyzed using the FMEA (failure mode and effect analysis) method and the fuzzy set method, as well as various methods of fuzzification and defuzzification. The results of all of the methods were compared with each other. The best solution from the analyzed ones was proposed.

Fault diagnosis of a computer interlocking system for railway signal control

The signal control of the railway transportation system is crucial for operational safety. This paper briefly introduces the computer interlocking system for railway signal control, describes the tree-structured neural network used for fault diagnosis of the interlocking system, and introduces the particle swarm optimization (PSO) algorithm for improvement. Finally, a simulation experiment was conducted on a railway station to compare the traditional back-propagation neural network (BPNN), the support vector machine, the traditional tree-structured neural network, and the improved tree-structured neural network for fault diagnosis. It was found that the topological structure of the device distribution in the railway station could be transformed into a tree structure, and with the introduction of hidden nodes, it could become a binary tree structure where each leaf node represents a device; the improved tree-structured neural network had the highest recognition performance for both two-class tasks (determining system failure or not) and multi-class tasks (identifying fault type).

A train timetable rescheduling approach based on multi-train tracking optimization of high-speed railways

PurposeThis paper aims to propose a train timetable rescheduling (TTR) approach from the perspective of multi-train tracking optimization based on the mutual spatiotemporal information in the high-speed railway signaling system.Design/methodology/approachFirstly, a single-train trajectory optimization (STTO) model is constructed based on train dynamics and operating conditions. The train kinematics parameters, including acceleration, speed and time at each position, are calculated to predict the arrival times in the train timetable. A STTO algorithm is developed to optimize a single-train time-efficient driving strategy. Then, a TTR approach based on multi-train tracking optimization (TTR-MTTO) is proposed with mutual information. The constraints of temporary speed restriction (TSR) and end of authority are decoupled to calculate the tracking trajectory of the backward tracking train. The multi-train trajectories at each position are optimized to generate a time-efficient train timetable.FindingsThe numerical experiment is performed on the Beijing-Tianjin high-speed railway line and CR400AF. The STTO algorithm predicts the train’s planned arrival time to calculate the total train delay (TTD). As for the TSR scenario, the proposed TTR-MTTO can reduce TTD by 60.60% compared with the traditional TTR approach with dispatchers’ experience. Moreover, TTR-MTTO can optimize a time-efficient train timetable to help dispatchers reschedule trains more reasonably.Originality/valueWith the cooperative relationship and mutual information between train rescheduling and control, the proposed TTR-MTTO approach can automatically generate a time-efficient train timetable to reduce the total train delay and the work intensity of dispatchers.

Key technologies and applications of intelligent dispatching command for high-speed railway in China

PurposeThe intelligent Central Traffic Control (CTC) system plays a vital role in establishing an intelligent high-speed railway (HSR) system. As the core of HSR transportation command, the intelligent CTC system is a new HSR dispatching command system that integrates the widely used CTC in China with the practical service requirements of intelligent dispatching. This paper aims to propose key technologies and applications for intelligent dispatching command in HSR in China.Design/methodology/approachThis paper first briefly introduces the functions and configuration of the intelligent CTC system. Some new servers, terminals and interfaces are introduced, which are plan adjustment server/terminal, interface for automatic train operation (ATO), interface for Dynamic Monitoring System of Train Control Equipment (DMS), interface for Power Supervisory Control and Data Acquisition (PSCADA), interface for Disaster Monitoring, etc.FindingsThe key technologies applied in the intelligent CTC system include automatic adjustment of train operation plans, safety control of train routes and commands, traffic information data platform, integrated simulation of traffic dispatching and ATO function. These technologies have been applied in the Beijing-Zhangjiakou HSR, which commenced operations at the end of 2019. Implementing these key intelligent functions has improved the train dispatching command capacity, ensured the safe operation of intelligent HSR, reduced the labor intensity of dispatching operators and enhanced the intelligence level of China's dispatching system.Originality/valueThis paper provides further challenges and research directions for the intelligent dispatching command of HSR. To achieve the objectives, new measures need to be conducted, including the development of advanced technologies for intelligent dispatching command, coping with new requirements with the development of China's railway signaling system, the integration of traffic dispatching and train control and the application of AI and data-driven modeling and methods.

Knowledge Management in Public Transport: a Portuguese Empirical Study

This paper aims to investigate knowledge management processes in a metro company. We focused on core knowledge and its impact on the overall performance of a public transport operator. It presents a case study from the Lisbon-based public transport operator Metropolitano de Lisboa, E.P.E. The challenges of knowledge management in a metro company, such as time savings and efficiency, can be mitigated by the creation of a structured and target-oriented knowledge framework and information architecture that enables knowledge reuse throughout KM aims the company or/and in specific communities of practices. The current study seeks to investigate the role of signalling experts in knowledge management in a metro company through the use of a case study based on accessing the documentation required to deliver their technical outputs. Qualitative methods were used to conceive, design, and implement the specific experience under analysis. The approach involved semi-structured interviews with a sample of five core operational managers and an online questionnaire directed at the study’s core knowledge actors (90 experts) and a Delphi Study applied to the five signalling experts. The results showed that optimizing knowledge management leads to increased operator efficiency and decision-making. The findings of the empirical case analysis combined with the literature review provide useful insights to construct a target-oriented knowledge management methodology in a metro company. One of the study’s key findings is the relationship between decision-making and knowledge management tools. The findings of the empirical case analysis, combined with the literature review, provide useful insights into the awareness of an urgent target-oriented knowledge management framework in a metro company. This study was built on the available data from Railway signalling metro experts, which may be perceived as limited in the overall context. We consider that there is no special bias associated with this area of expertise and that the overall approach could be adopted and further tested in any other metro company, regardless of size. This essay added novel information to the available body of knowledge by providing an in-depth analysis of a core discipline of metro mode by addressing the accessibility to information by Railway signalling professionals.

Choice of the Parameters of an EMI Monitoring System for an AC Traction Network

The problem of ensuring the electromagnetic compatibility of the traction network with railway signaling lines is of practical interest, since electromagnetic interference from the traction network can cause malfunctions in the signaling systems. In order to ensure the electromagnetic compatibility of traction current with track circuits, which are widely used as track vacancy sensors in front of a moving train, electromagnetic interference in rails is periodically monitored in accordance with their maintenance schedule, which makes it possible to detect excessive increases in the level of interference in the rails in a timely manner and prevent possible failures in signaling systems. The problem of developing embedded systems for continuous monitoring of harmonics in the traction network lies in the need to ensure the necessary measurement accuracy of the interference monitoring system for a traction network in accordance with the strict requirements of standards. The correct choice of control system parameters is difficult because the traction current is a non-stationary random process, and the alternating traction current, in addition, has a large dynamic range of harmonic values, their proximity to each other and to a powerful fundamental harmonic, as well as the limitations inherent in the discrete Fourier transform, associated with the impossibility of simultaneously improving the accuracy of measurements in the time and frequency domains, which leads to the need for compromises when choosing the parameters of the monitoring system. The work is devoted to the practice of applying the theory of analog-to-digital conversion and the windowed Fourier transform to develop a technique for correctly choosing the parameters of an electromagnetic interference monitoring system for traction lines.

Proposing a Train Speed Profile Generation Method in Railway Signalling Systems Based on Internet of Things (IoT): Performance and Stability Assurance

In the past years, the Internet of Things has created tremendous changes in various industries, including transportation systems and especially railway signalling systems. One of the issues that is very important in signalling systems is the design of trains speed profiles to control the movement of trains based on the defined headway and line conditions such as other trains positions. Information packet loss is one of the issues that should be considered in the field of Internet of Things and if this issue occurs, effective solutions should be adopted in the system for optimal performance. In this article, a method for generating speed profiles for moving block signalling systems in case of packet loss is proposed and the stability of the system is checked using the proposed method. Finally, we will implement the proposed method on a part of a railway line and examine the results.

Mechanical Characteristics and Vibration Control of Railway Signal Relay

Introduction: In order to solve the problems of time-consuming and poor effects of traditional mechanical vibration control methods for the relay, the mechanical characteristics and vibration control of railway signal relays are studied in this paper. Based on the analysis of the mechanical characteristics of railway signal relays, the mechanical characteristic parameters of the relay, such as contact force, initial pressure, contact clearance, and overtravel are explored. On this basis, mechanical vibration control is completed based on particle swarm optimization. Methods: First, sensors are used to collect the data on the railway signal relay, and the mechanical vibration control model of the railway signal relay is built. Then, the structure of the PID vibration controller and LQR vibration controller in the model is analyzed. Finally, the controller parameters are adjusted through particle swarm optimization to improve the mechanical vibration control effect of the relay. Results: The simulation results show that the average signal-to-noise ratio of the method is 67dB, the collected data has low noise, and the control time is short, which is 1.4 s. Conclusion: The displacement of the railway signal relay controlled by the method is always less than 0.15 mm, and the control effect is good, which can be widely used in practice.

A Microservices-Based Approach to Designing an Intelligent Railway Control System Architecture

The symmetry between customer expectations and operator goals, on one hand, and the digital transition of the railways, on the other hand, is one of the main factors affecting green transport sustainability. The European Train Control System (ETCS) was created to improve interoperability between different railway signaling systems and increase safety and security. While there are a lot of ETCS Level 2 deployments all over the world, the specifications of ETCS Level 3 are under development. ETCS Level 3 is expected to have a significant impact on automatic train operation, protection, and supervision. In this paper, we present an innovative control system architecture that allows the incorporation of artificial intelligence (AI)/machine learning (ML) applications. The architecture features control function virtualization and programmability. The concept of an intelligent railway controller (IRC) is introduced as being a piece of cloud software responsible for the control and optimization of railway operations. A microservices-based approach to designing the IRC’s functionality is presented. The approach was formally verified, and some of its performance metrics were identified.

Uninsulated Track Circuit Parameter Adjustment and Ballast Resistance Analysis

Uninsulated track circuits are increasingly used in railroad signaling equipment, but the external environment dramatically influences operating conditions. Using the relationship between uninsulated track circuits and ballast resistance, an equivalent four-terminal network model of track circuit transmission characteristics is constructed based on uniform transmission line theory to analyze the influence law of ballast resistance on track surface current. It also makes corresponding adjustments to the track circuit parameters to ensure that the track circuit can work reliably in all four different operating conditions to ensure the safety of railroad transportation.

Vibration signal-based defect detection method for railway signal relay using parameter-optimized VMD and ensemble feature selection

Railway signal relay (RSR) plays a critical role in the railway signaling system and its failure may bring serious consequences. At present, the manual-based RSR defect detection method has many shortcomings. A vibration-based defect detection method for RSR is proposed to solve this problem. First, since most of the variational mode decomposition (VMD) optimization strategies do not apply to the vibration signal of RSR, a parameter-optimized VMD based on a hybrid criterion of sample entropy (SampEn) and Pearson correlation coefficient (PCC) is proposed. Second, an ensemble feature selection method combining Filter method and Embedded method is proposed to select defect-sensitive features. The ensemble is considered as a multi-criteria decision-making (MCDM) problem and solved using the VIKOR method, which can integrate the advantages of each feature selection method to select the optimal feature subset. Finally, the effectiveness of the proposed method is verified by real vibration signals of RSR.

From Sensibility to Sublimity: Worshipping Land Community in Pearl S. Buck’s The Good Earth

This paper explores and analyses the kind of ecological sublimity the protagonist goes through despite poverty and significant modern development in China in Pearl S. Buck’s The Good Earth (1931) from an eco-critical perspective. Wang Lung, the protagonist, experienced wonderful transformations in China during his lifetime. The colonization, arrival of Christian missionaries, urbanization and construction of a railroad signal modernity in China. However, Lung feels ecological sublimity despite the ups and downs brought about by the series of transformations in China. The paper draws on ideas from the eco-critical insights anticipated by Aldo Leopold and E. O. Wilson. As a qualitative applied research, the focus lies on Leopold's concept of “land community” and Wilson’s idea of “biophilia”. Ecological sensibility is the only way to feel the earth’s community’s bliss even during modern development. The reverence for land community unbelievably renders the vibration of ecological sublimity. It provides spiritual freedom to people of all classes, religions and nationalities from around the world. In this sense, the land community offers sublime happiness in the world if we stop coveting its domain.

Research on the Visualization of Railway Signal Operation and Maintenance Based on BIM + GIS

To adapt to the “fine” and “extensive” management characteristics of railway signal equipment operation and maintenance, achieving real-time and interactive monitoring of signal equipment operation status, and developing an integrated approach to equipment operation and maintenance, this paper takes a comprehensive management perspective. To create a lightweight BIM model, the Garland folding algorithm is utilized to simplify the IFC file format. Building on this approach, the data are divided based on building component division standards to obtain separate files containing geometric information and semantic attributes. The geometric information files are converted to a 3D Tiles format, combining BIM semantic attributes with semantic attribute files through an intermediate format. Dynamic data management is achieved by setting the octree space index structure in combination with a view-frustum culling algorithm. Then, the 3D Tiles target file is imported into the Cesium platform, and Node.js is used to achieve three-dimensional visualization of railway signal operation and maintenance. The proposed method is verified using an inbound signal as an example to assess its feasibility. The results demonstrate the potential of the proposed method to achieve stable integration between BIM equipment full lifecycle maintenance and GIS geographical space display. Railway signal equipment is endowed with comprehensive one-click information query functions for equipment positioning and spatial analysis, improving the efficiency and scientific decision-making level of equipment operation and maintenance.

Rule-based anomaly detection for railway signalling networks

We propose a rule-based anomaly detection system for railway signalling that mitigates attacks by a Dolev-Yao attacker who is able to inject control commands to perform semantic attacks by issuing licit but mistimed control messages. The system as well mitigates the effects of a signal box compromised by an attacker with the same effect. We consider an attacker that could cause train derailments and collisions, if our countermeasure is not employed. We apply safety principles of railway operation to create a distributed anomaly detection system that inspects incoming commands on the signals and points. The proposed anomaly detection system detects mistimed control messages against light signals, points and train detection systems that lead to derailments and collisions without producing false positives, while it requires only a small amount of overhead in terms of network communication and latency compared to normal train operation.

GIS-Based Electric Service Resource Management System

<p>With the increasing investment in railway construction, China’s railway transport network is now very sound, the number of operating miles is growing, and the operating speed has also made a qualitative leap. At the same time, the safety and reliability of the operation of railway signal cables and other electrical equipment has also put forward higher requirements. At the present stage, the management of railway electrical services equipment mainly relies on manual management, which is cumbersome, inefficient and unsuitable for multi-user sharing. At the same time, the structure of railway electrical equipment is complex, and the components of the equipment are prone to aging, which can easily cause equipment failure. How to professionally manage electrical service equipment and improve the safety and reliability of electrical service equipment has become an urgent problem for railway electrical service departments. Geographic Information System (GIS) architecture uses spatial data layering technology to achieve multi-level and proportional display of equipment and facilities, which can provide visual display of professional facilities such as railway engineering, electricity and power supply, and carry out multi-source and multi-temporal intelligent analysis of data, provide geographical information service interface for various professions of engineering and electricity to meet their own functional requirements. Knowledge mapping is a key technology for acquiring knowledge and building a knowledge database in the era of big data. In order to explore the hidden information between railway electrical resources, integrate seemingly independent data into the knowledge base and apply them. In this paper, we design a GIS-based electric service resource management system in combination with knowledge mapping that can make data complete and well-structured after processing scattered and redundant information, and analyze and discuss the system’s architecture, functional requirements, key technologies and development prospects.</p> <p> </p>

Services interfaces for interoperability of signaling computer interlocking on borders

<p>Technological developments in the field of railway signaling have allowed more and more flexibility in the management of rail traffic, especially with computer interlocking. However, differences in signaling principles from one country to another as well as differences in the structure of interlocking software and communication protocols depending on suppliers lead to interoperability difficulties at the borders between computer interlocking. Some deployed projects deal with interoperability issues regarding the communication of signaling information between the train and interlocking like the European rail traffic management system (ERTMS) project. Unfortunately, the interoperability between interlocking themselves is still not achieved. Some deployed projects deal with interoperability issues regarding the communication of signaling information between the train and interlocking like the ERTMS project. Unfortunately, the interoperability between interlocking themselves is still not achieved. This article draws up a proposed model for interfacing at the interlocking boundaries based on service-oriented architecture (SOA). In addition, to ensure the coupling of SOA services to the internal functions of the signaling computer interlocking, a distributed architecture of programmable logic controller according to the IEC 61499 standard is suggested.</p>

Advanced Railway Signaling System

Advanced Railway Signaling System

<b>Trends in Research and Development Activities Related to Railway Signalling and Telecommunication Systems</b>

<b>Trends in Research and Development Activities Related to Railway Signalling and Telecommunication Systems</b>

Onboard train speed optimization for energy saving using the prediction of block clearing times under real-time rescheduling

Energy-saving driving is crucial during railway operation, especially in case of disturbances that require timetable rescheduling. This paper presents a method for the dynamic onboard tuning of energy-efficient speed profiles after the real-time train rescheduling process under a fixed block signaling system for mixed traffic. Similar to the idea of connected driver advisory systems, trains constantly communicate with a central traffic management system. After the rescheduling process, this system provides recommended time corridors for the passing of block signals that depend on the predicted clearing times of the block sections. These recommendations are then used for individual energy optimization of single train runs by avoiding unnecessary braking in front of block signals and maximizing cruising distances. The method is tested and evaluated on a representative line segment of the ELVA, the Railway Signaling Lab at RWTH Aachen University under realistic conditions. Energy consumptions are compared for different prediction time horizons at which the recommendations are available to the train's onboard system. In the examined test case of two trains, the energy-consumption could be decreased by up to 53% compared to operation without any rescheduling system. Thus, the proposed method is able to reduce energy consumption significantly.