CBTC System Research Articles

CBTC 시스템에서 무선통신 두절 시 이동 폐색 확장 방호 기능에 관한 연구

CBTC 시스템에서 무선통신 두절 시 이동 폐색 확장 방호 기능에 관한 연구

Design and research of train-centric autonomous control CBTC system

Existing CBTC systems suffer from a number of limitations, some of which include convoluted communication between the ground and trains, costly construction, and high costs associated with the installation of ground equipment. The purpose of this study is to further improve the operational efficiency of a train-centric autonomous CBTC system by analyzing the system design, control principles, and module functioning. The planning of ground and onboard equipment will be the main research objects of the novel system. When compared to conventional CBTC systems, the TACS architecture, most notably in the OC and train-train communication modules, changes the control mode from ground-centric to train-centric. This results in an increase in the overall efficiency of the system, and a new train operation scenario of the virtual coupling is introduced to increase the flexibility. The TACS architecture that was designed paves the way for the engineering advancement of the system and establishes the groundwork for it.

Research on the virtual coupling scenario of the CBTC system based on vehicle-to-vehicle communication

In order to simplify trackside equipment and realize shorter travel intervals, this paper proposes a virtual coupling CBTC system. The system structure, key technology, and train function module of the virtual coupling CBTC system scheme are analyzed. This paper also analyzes the system operation in the normal and fault operation scenarios and gives suggestions on the safety measures taken in the fault scenario, which provides reference for the engineering application of the system. It is found that the virtual coupling operation based on vehicle-to-vehicle communication can effectively reduce the operation cost and improve the operation efficiency.

Research on urban rail train control system based on train to train communication

The new train control system VBTC based on train to train communication adopts the idea of on-board centralization, regards switches and sections as trackside resources, integrates the functions of interlocking and zone controller into on-board, and the train independently manages line resources and determines the train operation control scheme. Compared with the existing CBTC system, VBTC system not only simplifies trackside equipment, but also improves operation efficiency, reduces operation and maintenance costs, and can better solve the problems of shortage of commissioning time and limited room space during overhaul and reconstruction of old lines. This paper analyzes the key technologies of train control system under train to train communication technology, designs the structure of VBTC system on-board module and object controller, and analyzes the control line resource flow of trackside object controller. VBTC train control system breaks through the inherent mode that all rail transit train control systems rely on station and trackside equipment to realize train operation control, and completely relies on on-board train control, which is in line with the development trend and direction of train control system.

Comparison of Energy Optimization Strategies in CBTC System for a Tolerable Travel Time Increase

Günümüzde, birçok metro hattı projesinde sinyalizasyon sistemi olarak haberleşme tabanlı tren kontrolü (CBTC) sistemleri kullanılmaktadır. Otomasyon seviyesi-2 (GoA2) veya üzerinde bir otomasyon seviyesine sahip sinyalizasyon sistemi trenleri, önceden tanımlanmış hız profillerini dikkate alarak sürmekte ve tren trafiğini yönetmektedir. CBTC sistemlerine ilişkin IEEE std. 1474 standardı özellikle trenin hızlanması (ivmesi), trenin boşta gitmesi ve trenin frenlemesi gibi parametreleri enerji optimizasyon algoritması için kullanabileceğini tanımlamaktadır. Bu makalede trenlerin gidiş ve dönüş yönlerindeki toplam seyahat süresinde tam performanslı kullanıma (tam güç modu) göre, işletme firmalarının kabul edebileceği ve tren sayısını arttırmayacak olan, %4 uzatmaya yol açan farklı parametre setlerinin ve boşta gitme stratejisinin, sistemin enerji tüketiminde ne kadar avantaj sağladığı örnek bir metro hattı verileri ile incelenmiş ve ele alınan durumlarda boşta gitme stratejisinin %21,34’e kadar daha az enerji tüketimi oluşturacağı gösterilmiştir. Çalışmada hem tren performans/hareket hem de cer gücü sistemi yük akış analizini birlikte gerçekleştirebilen güçlü bir raylı sistem simülasyon yazılımı olan Hi-SimuX - Raylı Sistem Simülasyon Yazılımı ile farklı performans parametre setleri ve boşta gitme stratejisine ait simülasyonlar gerçekleştirilmiştir. Tek tren durumuna ilişkin senaryolarda tren performans simülasyonları ve ardından çok sayıda trenin farklı işletme sıklıkları ile koşturulduğu çoklu tren senaryolarına ait cer gücü sistemi simülasyonları gerçekleştirilmiştir. Hem tek tren durumu için yapılan tren performans simülasyonları hem de farklı işletme sıklıklarının olduğu çoklu tren durumu için koşturulan cer gücü simülasyonlarındaki enerji tüketimi değerleri kıyaslanmıştır. Yapılan simülasyonlar, tam güç moduna göre aynı miktarda süre uzatımına yol açan boşta gitme stratejisinin kullanımının performans parametrelerinin kullanıldığı diğer enerji optimizasyon yaklaşımlarına göre daha fazla enerji tasarrufu imkânı verdiğini göstermiştir. Çoklu tren işletme durumunda işletme sıklığına bağlı olarak, boşta gitme stratejisi %14,11-21,34 arasında tasarruf sağlarken ikinci iyi olan stratejide ise %8,7-11,46 arasında enerji tasarrufu sağlamaktadır.

Correction of Tunnel Wireless Propagation Model Based on TD-LTE

Because WLAN uses the open frequency band of 2.4GHz or 5.8GHz and does not need to be approved by the radio management department, it is inevitable that it will interfere with the wireless transmission of rail transportationt vehicles. The rail transit system of some cities introduces TD-LTE into the CBTC system, but the path loss generated during the transmission has a non-negligible impact on the urban rail transit network propagation plan. Therefore, the accuracy of the radio wave transmission model has an impact on the urban rail transit system. The importance of transportation is self-evident. This paper selects the SPM propagation model for correction, and uses the PSO algorithm to make up for the problem of BP easily falling into local optimality, and obtains the corrected propagation model and the measured data is closer.

Research and design of data communication subsystem of urban rail transit CBTC system

With the intensive development of urban rail transit in China, urban rail transit has increasingly become the preferred mode of transportation for citizens due to its convenience and speed. The design and construction of an efficient and highly reliable urban rail transit system has become an urgent requirement for urban rail transit construction. This article mainly introduces the research and design of the data communication subsystem of the urban rail transit CBTC system, and intends to provide some ideas and directions for studying the data communication subsystem of the urban rail transit CBTC system. This article uses a variety of methods, such as consulting literature and information research on trademark system suppliers. The development status of CBTC system and data communication subsystem is analyzed, and the importance of data communication subsystem and the necessity of the entire CBTC system are analyzed. The experimental results of this article show that in the design, development and application engineering of the CBTC system, the DCS subsystem accounts for 55%, the system is complex, and the environment is changeable, occupying an important position. When the DCS has a problem, it may cause drive failure, affect normal functions, cause greater losses, and even cause huge safety accidents. Therefore, the reasonable, reliable and safe design of the DCS subsystem is of great significance.

Modeling and Verification of CBTC system security Communication protocol based on time Automaton

With the rapid growth of population and economy, passengers’ demand for urban rail transit is increasing, and it is difficult for single-line rail transit to meet passengers’ demand for rapid transfer. Therefore, the interconnection between urban rail lines has been the focus of development in recent years. Therefore, the secure communication between various devices is a very important link in the interconnection test. Chongqing Metro Line 10 is the first metro line to realize the interconnection based on the secure communication protocol, in which the specific parameter setting in the secure communication protocol is specified, so the method is needed to verify the security of the protocol. In this paper, the time automaton theory is adopted to carry out the corresponding modeling work for the two key safety key contents of the safety communication protocol in the railway, namely the protocol chain building process and the protocol retransmission process, and verify its security and timeliness. Finally, a test platform is built to test the communication function between the systems.

A Method of Generating Engineering Test Sequence for Urban Rail Transit CBTC System Based on Formalization

In recent years, with the rapid development of urban rail transit, Communication Based Train Control system is very important to improve the operation efficiency and ensure the traffic safety. Before urban rail transit lines are put into operation, they need to be tested strictly. In view of the lack of unified test standards, specifications and low test efficiency, a formal test sequence generation method for CBTC system is proposed. Firstly, the test line is divided into several test segments; secondly, analyze the constraint conditions of test cases and get the expression of constraint relationship of test cases; thirdly, analyze the characteristic quantity that can represent the line characteristics, and get the line characteristic expression; and then match test cases with test segments using matching algorithm; finally, concatenate test cases into test sequences using the concatenation algorithm. The results show that the test sequences generated by this method meets the test requirements of CBTC system. The test sequences cover all test cases. And the method can effectively improve the test efficiency.

Research on the Generation Method of CBTC Test Sequence

Before the CBTC line is opened for operation, it should be tested on site to verify whether the system meets functional requirements, design specifications, and operational requirements. At present, there is no uniform test standard for the field test work of the CBTC system, especially the lack of standard and systematic field test sequence generation methods. In this paper, the test-trip based field test scheme is studied, and the test-trip based field test sequence generation method is proposed, and various rules and definitions under the framework of the method are explained.

Towards Safety-Risk Prediction of CBTC Systems With Deep Learning and Formal Methods

Communication-Based Train Control System (CBTC) system is an automated system for train control based on bidirectional train-ground communication. Safety-risk estimation is a vital approach that strives to guide the CBTC system to guarantee the safe operation of vehicles. We propose a deep learning method to predict safety-risk states that combined with formal methods. First, the impact factors are selected, and the movement authorization (MA) failure rate is calculated by statistical model checking. Then, we use a deep neural network to model the relationship between the safe-risk states and the train operation status. Experimental results show that our method can achieve an accuracy of 97.4% on safety-risk prediction, and exceeds the baseline methods.

Safety monitor for train‐centric CBTC system

Train-centric communications-based train control (TcCBTC) system is a new solution for urban transit signalling. Compared to traditional train control systems, the on-board equipment is becoming more powerful and more complex. Due to its safety-critical nature, specialised technologies must be adopted to guarantee the safety of the system. To address the safety verification difficulty of the control logic for the new system, this study presents an innovative topology-based method for guaranteeing the train control safety. First, a railway network is described as a metric space, and then, topological spaces are introduced to express the movement authority and train trajectory. On the basis of the topological description, the safety rules are checked by performing a series computation of topology theorems. Finally, a case study has been carried out on a real metro line in China. The result shows that the proposed method strictly meets the safety verification and achieves excellent performance.

Characteristics of event recorders in Automatic Train Control systems

The development of railway transport in the current times is very noticeable, it is connected with the growing needs of movement as well as the development of information engineering. The increase in the demand for transport requires the implementation of solutions that increase the efficiency of the transport system. Both long-distance, agglomeration and metro railways can use different systems due to their specificity. Nevertheless, there is a noticeable trend in the development of systems supporting or even replacing the driver by the automation of selected activities. Such systems allow to reduce trains headway and thus increase the capacity of the line. CBTC class systems (Communications-based train control) belong to automatic train systems and are based on wireless transmission. The main purpose of using such systems is to increase the frequency of running trains while maintaining the level of safety. Computers that are on the system equipment record, process and analyse very large amounts of data. An essential element of such systems are recording units. The parameter recorders can be divided into technical and legal ones. However, for CBTC class systems, there is no obligation or requirement to use legal recorders as it is in the case of ETCS. However, it is necessary to use event recorders, and these are subject to the requirements set out in the PN-EN 62625-1: 2014 standard. The recorders are a very important component of safety systems, which is why they were analysed in this article. Both the driver, the vehicle and the infrastructure should be subject of continuous monitoring. The occurrence of an adverse event (not necessarily leading to an incident or accident) should be analysed and used to improve safety procedures. Currently, automatic systems are still developing and we are not able to accurately assess what the causes and effects of certain events may be, which is why data collection and analysis is particularly important. The article presents the general specification of the CBTC system. The parameters and properties of driving recorders should be presented. This article is co-financed by the European Union POIR.01.01.01-00-0276/17

Research and Implementation of CBTC Simulation Test Platform Based on CS Architecture

This article has described the simulation test platform system researched and developed on the basis of the CBTC system and has introduced the overall architecture and requirements of the system. It has proposed a design and implementation solution to the CS architecture. This solution makes the entire system which has distributed functions with simple deployment and great extensibility.

The research of automatic speed control algorithm based on Green CBTC

Automatic speed control algorithm is one of the core technologies of train operation control system. It’s a typical multi-objective optimization control algorithm, which achieve the train speed control for timing, comfort, energy-saving and precise parking. At present, the train speed automatic control technology is widely used in metro and inter-city railways. It has been found that the automatic speed control technology can effectively reduce the driver’s intensity, and improve the operation quality. However, the current used algorithm is poor at energy-saving, even not as good as manual driving. In order to solve the problem of energy-saving, this paper proposes an automatic speed control algorithm based on Green CBTC system. Based on the Green CBTC system, the algorithm can adjust the operation status of the train to improve the efficient using rate of regenerative braking feedback energy while ensuring the timing, comfort and precise parking targets. Due to the reason, the energy-using of Green CBTC system is lower than traditional CBTC system. The simulation results show that the algorithm based on Green CBTC system can effectively reduce the energy-using due to the improvement of the using rate of regenerative braking feedback energy.

Axle Counter System 국산화 개발을 위한 현장시험 결과분석

A track circuit has used stably more than 100 years for detecting train position, but solution of track circuit sort circuit incapacity due to a rust is necessary for side line in station yard, coast line and level crossing for conventional line in rural line. Domestically, Axle Counter System(ACS) has partially used for Hot Box System for high speed line and turnout for CBTC system. In contrast, most of countries has used ACS not only trunk line but also rural line and its application has increased for metro, electric car and industrial railway. In this paper, we has verified the operating status of ACS which installed with existing track circuit through log analsis to implement pilot application in mail track and turnout in station yard. And interface test with interlocking system has conducted at Obong shunting yard, as well as Cheongju station and has analyzed test result. Based on a test result, we made fail safe design, manufacturing skill and established system requirement specification for the smooth operation and maintenance.

CBTC System Dynamic Data Security Verification Method

Communication based train control system as a train control system is designed to ensure driving safety, the system description and system function of the real environment is driven by different types of data. Data security is an important component part of CBTC system security, the dynamic data as interactive data within the system is more important influence on system safety, it is necessary to put forward the formal modeling for dynamic data security verification. This paper puts forward a kind of dynamic data security verification method for train control system based on UPPAAL. The unified modeling language (UML) is adopted to train control scene modeling analysis, through model transformation method to convert the UML sequence diagram to timed automata model, using UPPAAL validation tool for train control scenario simulation analysis, through dynamic data to meet security constraint conditions shows that the dynamic data security.

CBTC Simulation Platform Design and Study

In order to train and test the functionality of the CBTC signal system, this paper designs simulation platform’s architecture and function module based on the CBTC principle firstly. Then, it detailedly discusses the main content and key algorithms about train module and trackside module. Finally, it builds CBTC simulation test platform, used for training of rail transit signal related specialized student and detecting the main function of actual CBTC system based on Shanghai Metro Line 9.

고속 철도 채널 환경에서 시공간 블록 부호 성능 비교

현대의 철도는 인력 및 물류 수송에 대한 요구의 급증으로 인하여 기존의 궤도 회로 기반의 제한적인 선로 용량 개선에 대한 방안으로 통신 기반 열차 제어(CBTC) 시스템이 제안되었다. CBTC에서는 열차와 승객의 안전을 위해 신뢰도가 높은 통신 시스템이 요구된다. 다양한 간섭 및 잡음 요인을 포함하는 무선 채널 환경에서 성능 향상을 위한 방안 중 하나인 다이버시티 기법은 다수의 송수신 안테나를 이용하여 데이터 전송의 신뢰도를 향상시킨다. 본 논문에서는 시공간 블록 부호화 기법을 철도 채널 환경에 적용하여 그 성능을 분석한다. 이를 위해 철도 환경에 적합한 채널 모델 적용으로 철도의 중요한 부분을 차지하는 교량 환경에 대해 라이시안 페이딩 모델을 가정하였다. 또한 이동 통신 시스템에서 성능 열화의 가장 큰 요인 중 하나인 도플러 현상을 고려하여 다양한 채널 환경에서 시공간 블록 부호화 기법의 성능을 시뮬레이션을 통해 분석하였다. 시뮬레이션 결과, 교량 환경에서는 위상오차에 대한 성능의 열화 정도가 다이버시티 차수에 무관하며, 변조 방식의 성상도에 관계됨을 알 수 있다. Due to the rapid increase in demand for transportation of human and freight in modern railway systems, the CBTC system has been proposed, which is the solution for improvement of the line capacity that has been limited by the conventional track circuit based train control system. In the CBTC system, higher reliability of the communication system should be guaranteed for the safety of passengers and trains. However, due to the inherent characteristics of the wireless channel environment, performance degradations are inevitable. The diversity techniques can increase the reliability of data transmission using multiple antennas. In this paper, we investigate the performance of the STBC in the railway channel environment. Rician fading model is used for the viaduct scenarios which take important roles in the railway system. Also, considered is the Doppler effect which is an important factor in the mobile communication system. Simulations are performed to analyze the performance of the STBC in various channel environments. Results show that the performance degradation due to the phase error in viaduct scenarios is independent of the diversity order but is affected by the constellation of the modulation.

Independent Technology of CBTC System and Management Innovation in Urban Rail Transit

This paper introduces two technical innovations in the signal demonstration project of Beijing Subway Yizhuang Line: the “free wave antenna + waveguide” combined transmission and the "minimum system" simulation. It also summaries the demonstration project management concepts and innovative practice experiences. Analyzing the technology and management innovation, we expect to provide a reference for the progress of the autonomy of the other rail transport high-end and core technology.