• Research on Scheme and Experimental Verification of Adding Automatic Turn-back Function Based on High-speed Railway ATO
• Wu Peidong, Wang Shuo, Zhang Youbing
• 2023 Vol. 20 (8): 1-7,22. DOI:10.3969/j.issn.1673-4440.2023.08.001
• Abstract ( ) PDF (2803KB)( )
• To further extend the automation scope of the high-speed railway ATO system, a brief analysis of the high-speed railway automatic turn-back operation scenario is presented. Based on the high-speed railway ATO system, a scheme is proposed to add the automatic turn-back function, and the interfaces and functions of the ground equipment, the head on-board equipment and the tail on-board equipment are defined and assigned. The different state transitions during the automatic turn-back process are described. Based on the semi-physical simulation platform, the scheme is experimentally verifi ed and the results prove its eff ectiveness.
  
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• Research and Analysis of Railway Signal Circuit Design Safety
• Zhang Changping, Bai Shuhan
• 2023 Vol. 20 (8): 8-12. DOI:10.3969/j.issn.1673-4440.2023.08.002
• Abstract ( ) PDF (1177KB)( )
• Railway signal circuits are used to control signal equipment to ensure driving safety and improve transportation efficiency with safety and reliability. However, in the actual use of relay circuit equipment, it is possible that the circuits fail to respond in a safe manner in the event of failure. This paper analyzes the potential unsafe factors in signal circuit design, conducts research and fault hypotheses, analyzes the risk factors of circuit design, eliminates loopholes and hidden dangers through checking and benchmarking, prevents problems before they occur, and ensures that the signal circuit design conforms to the "fail-safe" principle. 
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• Discussion on Special Scenarios of Switchable Balise Group for Large Number Turnouts in CTCS-2 Level Train Control System
• Zhang Huizhi
• 2023 Vol. 20 (8): 13-16. DOI:10.3969/j.issn.1673-4440.2023.08.003
• Abstract ( ) PDF (1054KB)( )
• This paper fi rstly describes the setting of switchable balise group for large size turnouts and the method of sending telegrams in the high-speed railways. Then an analysis is conducted on the reasons for train speed reduction when passing through large turnouts in special scenarios such as inconsistent telegram data, insuffi  cient distance of approaching sections and short sections. Finally,  it summarizes several types of problems frequently encountered in engineering design and data compilation, and proposes the corresponding solutions, which have certain guiding signifi cance for improving the operational effi  ciency of high-speed railways.
  
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• Scope of Integration Test and Commissioning and Problem Analysis of Signal System for Yancheng-Nantong High-speed Railway
• Jin Dong, Zhou Yongjian
• 2023 Vol. 20 (8): 17-22. DOI:10.3969/j.issn.1673-4440.2023.08.004
• Abstract ( ) PDF (1030KB)( )
• Due to its unique characteristics, the Yancheng-Nantong High-speed Railway involves many signal equipment manufacturers, complex interface relationships, and frequent modifi cations to adjacent line stations. How to complete the integration test and commissioning safely and effi  ciently has become the primary goal of each signal integration manufacturer. Based on the test outline of the testers and the actual engineering situation on site, the scope of test cases applicable to the Yancheng-Nantong High-speed Railway and the test scope of train operation on related lines are analyzed and clarifi ed. In view of the problems found in the test process, with the help of various auxiliary tools such as Train Control Engineering Data Sheet for this Railway, JRU software, RBC data analysis software, etc., the papper introduces the root causes of the problem from different perspectives, provides solutions, and summarizes the importance of the test scope and problem analysis to the integration test  and commissioning, and it also provides an important scientifi c basis for the operation of the line.
  
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• Research on Implementation and Application of CTC Regional Centralized Control System
• Li Yongqiang, Fang Yubao, Xi Chunhua
• 2023 Vol. 20 (8): 23-27. DOI:10.3969/j.issn.1673-4440.2023.08.005
• Abstract ( ) PDF (2334KB)( )
• In order to meet the demand for centralized control of CTC central stations of common speed railways and realize the goal of reducing personnel and increasing effi  ciency in modern railway transportation, the CTC regional centralized control system scheme can be deployed according to the transportation demand of lines and stations on the premise that the overall system structure and operation organization principle of CTC remain unchanged. Through in-depth analysis of CTC regional centralized control system structure, system function realization and system deployment scheme, this paper discusses the system function realization, project implementation and the improvement eff ect on railway construction and operation benefi ts. It provides support and reference for the high-quality development of railway transportation in China. 
  
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• Research on Realizing Automatic Change of Train Numbers of Inter-city Railway Turn-back Stations Based on CTC System
• Wang Baobao
• 2023 Vol. 20 (8): 28-31，46. DOI:10.3969/j.issn.1673-4440.2023.08.006
• Abstract ( ) PDF (1176KB)( )
• Based on the principle of CTC system to realize the tracking of train number, this paper expounds the process of realizing the logic of automatic change of train number of CTC system after the train arrives at the turnback station. Taking Baiyun International Airport North Turnback Station as an example, the process and operation mode of realizing the automatic change function of train number in the situation of turning back in or after the station are illustrated. It solves the problem that the signal cannot be cleared according to the plan due to the train number modifi cation error and the train number modifi cation delay caused by the dispatcher manually modifying the train number at the turnback station. 
  
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• Research on Interference Coordination Between Public and Private Network Systems in Next Generation Railway Mobile Communication
• Zhang Chi, Kou Ming, Liu Xing, Guo Ruibin
• 2023 Vol. 20 (8): 32-36. DOI:10.3969/j.issn.1673-4440.2023.08.007
• Abstract ( ) PDF (1424KB)( )
• This paper mainly focuses on the frequency interference between public and private network systems in the next generation of railway mobile communication technology, and studies the causes of the interference, the scenarios of the interference and the methods to suppress the interference. The requirements of base station isolation degree in 3GPP are studied and the deployment requirements of wireless system between public and private networks are given. This paper shows that the parameters of VSWR, out-of-band signal rejection ratio and fi lter insertion loss are mutually restrictive. Through simulation, the relationship among the three parameters and the fi lter index requirements of wireless communication systems in the railway private networks are obtained.
  
  
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• Comparative Analysis of Three Architecture Platforms of Railway Integrated Video Monitoring Systems
• Liu Yueyao, Chen Qian, Cao Kun
• 2023 Vol. 20 (8): 37-40，58. DOI:10.3969/j.issn.1673-4440.2023.08.008
• Abstract ( ) PDF (1325KB)( )
• Traditional architecture, cloud computing & cloud storage architecture, and hyper-converged architecture are the three mainstream solutions for the construction of integrated video platforms. This paper conducts some quantitative comparative analysis from the aspects of technical architecture, equipment scheme and power consumption under certain constraints, and presents the specifi c calculation process, the advantages and disadvantages of each platform architecture scheme and the scope of application. It provides a reference for the selection of railway integrated video transformation platform. 
  
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• Research on Selection of Video Surveillance Cameras for Railways
• Chen Hongyu
• 2023 Vol. 20 (8): 41-46. DOI:10.3969/j.issn.1673-4440.2023.08.009
• Abstract ( ) PDF (1077KB)( )
• Taking customer demands into consideration, this paper analyzes and sorts out the development and changes in camera types and specifi c technical indicators of comprehensive video surveillance systems of railways. It systematically summarizes the crucial technical information about the cameras that are widely used in projects, identifi es the key issues to be considered when selecting cameras for engineering construction, and puts forward recommendations for camera selection. This paper provides guidance for the maintenance of existing video systems and for new, improved and expanded projects.
  
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• Research and Application of Apriori Algorithm in Analyzing C3 Wireless Communication Timeout
• Feng Yingchen
• 2023 Vol. 20 (8): 47-51. DOI:10.3969/j.issn.1673-4440.2023.08.010
• Abstract ( ) PDF (1327KB)( )
• Wireless timeout has become one of the main problems affecting the safe and stable operation of CTCS-3 train control system.Traditionally, analysis of such timeout issues relies on manual processing, resulting in a heavy workload and low effi  ciency. Aiming at solving the problem of CTCS-3 train control system wireless timeout, this paper presents an intelligent analysis technology based on data mining analysis algorithm, and uses the Apriori algorithm to comprehensively analyze all kinds of monitoring data so that  fault causes are located more effi  ciently and accurately. 
  
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• Research on Stress Detection Technology for Suspended Permanent-magnet Maglev Track Box Girder Based on FBG and EMD
• He Hangyu, Wang Suier, Wu Chunxiao, Wang Sheng, Li Qing
• 2023 Vol. 20 (8): 52-58. DOI:10.3969/j.issn.1673-4440.2023.08.011
• Abstract ( ) PDF (2798KB)( )
• This paper proposes a Fiber Bragg Grating (FBG) stress detection technology based on Empirical Mode Decomposition (EMD) for suspended permanent magnet maglev box girder, which is used to detect the stress of the track box girder when the vehicle passes through, check whether the stress is within the safe range, and ensure the operation safety and stability of vehicles.Considering the infl uence of strong magnetic fi eld and electromagnetic interference, the FBG grating sensing stress 
  detection scheme without electricity on the track is adopted, and a test point is respectively arranged at the travel position of the upper and lower guide wheels. The FBG test point is subject to both low-frequency flexure stress and high-frequency guide wheel stress, and the EMD method is used to separate the two stresses. The experimental results show that the test results of vehicle passing stress in line with expectations. The stress detection technology for track box girder described in this paper can effectively ensure the health of track box girder and the operation safety of vehicles. 
  
  
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• Exploration of Intelligent Application of 5G Public Network Specialized in Nanjing Metro
• Yang Yong, Sun Shumiao, Wang Guohua, Wu Ke
• 2023 Vol. 20 (8): 59-65. DOI:10.3969/j.issn.1673-4440.2023.08.012
• Abstract ( ) PDF (2121KB)( )
• This paper takes the exploration of the application of 5G in Nanjing Metro as the starting point, makes use of the high bandwidth and low latency characteristics and resource isolation means of 5G on the public network to empower the urban rail transit industry, covers all the scenarios of rail transit, creatively proposes a cross-industry business model, explores a green and low-carbon development path suitable for the urban rail transit industry, and achieves noticeable results in the coordinated development of digitalization and greenization, promoting the high-quality sustainable development of the urban rail transit industry.
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• Correlation Analysis Between Quality of Curve Rail Grinding Operations and Metro Vehicle Body Vibration Response
• Li Xianpeng, Bai Lei, Lü Jintong, Ding Ming, Li Qing
• 2023 Vol. 20 (8): 66-71. DOI:10.3969/j.issn.1673-4440.2023.08.013
• Abstract ( ) PDF (1832KB)( )
• Curve rail grinding for metros can effectively reduce the lateral and vertical vibration acceleration of the vehicle, thereby improving the running stability of vehicles. Using the running stability measurement of vehicles, the paper proposes a vibration evaluation index to evaluate the vibration response degree of the vehicle body passing through a curve and to assess the quality of the curve equipment. To comprehensively evaluate the immediate effect and the ongoing effect of the maintenance quality, a recovery coeffi  cient of the rail grinding operation is proposed. Furthermore, a correlation analysis model between vehicle body vibration response and the quality of the curve rail grinding operation is established. The actual data of Zhengzhou Metro Line 1  is used to verify the 
  proposed model. The calculation results show that the model can eff ectively analyze the correlation between the vehicle body vibration response and the quality of rail grinding operations, and play a major role in guiding the track maintenance.
  
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• Research on On-board ATP Control of Gear Rail and Wheel Rail Switching of Rack Railway Trains
• Liu Junfeng, Jiang Biao, Wang Cheng
• 2023 Vol. 20 (8): 72-77. DOI:10.3969/j.issn.1673-4440.2023.08.014
• Abstract ( ) PDF (1414KB)( )
• This paper introduces the characteristics of mountain rack railway trains and their starting status  in China. The particularities of the signal system in the safety control of the rack railway trains are analyzed. The control strategy of the signal system in the process of "gear in" and "gear out" of the mountain rack railway trains is described emphatically. It also analyzes and discusses the calculation of safety protection curves of signal system when a rack railway train switches between the gear rail area and the wheel rail area. The methods of stationary-train switching and dynamic switching are proposed. 
  
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• Switching Scheme of OCC and BOCC in Fully Automatic Operation
• Xue Qiang, Zhang Yonghui
• 2023 Vol. 20 (8): 78-82. DOI:10.3969/j.issn.1673-4440.2023.08.0015
• Abstract ( ) PDF (1270KB)( )
• Fully automatic operation system has the characteristics of strong professionalism, complex technical equipment and strong timeliness in urban rail transit. However, operating control center (OCC) may become paralyzed in times of extreme disasters, resulting in the failure of all professional  systems to complete normal functions, thus affecting the normal operation of urban rail transit. The backup operational control center (BOCC) is defi ned as the essential confi guration of the fully automatic operation system of urban rail transit, and the overall availability and safety of system are greatly improved with the addition of BOCC. This paper analyzes the internal redundant switching mechanism, the typical configuration of the equipment, and the impact of switching between the interfaces of the core professional system and the switching scenarios of the core system of OCC and BOCC of signal systems, data communication system and integrated supervision and control systems. Based on the above description and the comparison of the advantages and disadvantages of switching design, this paper provides reference and guidance for the core professional system switching design of the OCC and BOCC for fully automatic operation in urban rail transit. 
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• Application and Optimization of Industrial Ethernet PROFINET in Platform Door Systems
• Li Anfu
• 2023 Vol. 20 (8): 83-89. DOI:10.3969/j.issn.1673-4440.2023.08.016
• Abstract ( ) PDF (1313KB)( )
• This paper introduces the system composition and working principles of the platform door systems, as well as two mainstream fieldbus control systems in the platform door industry of urban rail transit at home and abroad: the systems  with the first generation of fi eldbus as the core, represented by CAN-BUS or Modbus; and the systems with the second generation fi eldbus as the core, represented by Profinet industrial Ethernet. Their network composition, topology, and system advantages and disadvantages are detailed in this paper. Aiming at solving the problems of complex communication network and a large number of nodes in the existing systems, an improved scheme is proposed, which is enhancing the DCU function through integration and adopting dual-master redundancy. The scheme has good engineering applications and guiding signifi cance in the fi eld of the industrial upgrading of the platform door systems and the popularization and application of industrial Ethernet in such systems. 
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• Analysis and Optimized Design of Approach Signal Lighting Circuit of a Station
• Li Sha
• 2023 Vol. 20 (8): 90-94. DOI:10.3969/j.issn.1673-4440.2023.08.017
• Abstract ( ) PDF (1165KB)( )

• For the automatic inter-station block section with a design speed of 120 km/h in the signal construction drawing of a station, the lighting circuit for the approach signal in this drawing is analyzed. When setting the straight receiving route going through the turnout, the home signal displays a yellow aspect and the approach signal displays a green and yellow aspect. When the train moves into the second approach section and the approach signal aspect changes from green and yellow to yellow, the filament

  supervision relay (DJ) and the second fi lament supervision relay (2DJ) are energized at the same time, causing the lighting current of the approach signal to exceed the working current range of the fi lament relay. This poses a certain risk when using the approach signal.Therefore, it is necessary to optimize the design of the approach signal circuit. This paper analyzes the connection formulas of the signal lighting circuit in diff erent scenarios, simulates the signal aspects when the train enters the first and second approach sections, carries out comparative calculations, identifi es the key points of inconsistency, and provides solutions. 

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• Problem Analysis and Improvement of Liaison Circuit Between Stations
• Hu Jinghai, Wang Yucong, Cai Weiwei
• 2023 Vol. 20 (8): 95-100. DOI:10.3969/j.issn.1673-4440.2023.08.018
• Abstract ( ) PDF (1355KB)( )
• When it is not possible to install a distant signal between two adjacent railway stations, a liaison circuit between the stations can be used as a block device. This paper mainly studies the typical problems that involve the acquisition drive circuit which occur when Computer Based Interlocking (CBI) is combined with the liaison circuit between the stations, including the problem of automatic reversal of section direction when the CBI system of the receiving station restarts, and the problem of“double approaching” when a departure route is set and then immediately canceled.This paper analyzes the causes, and puts forward improvement ideas and specifi c solutions in order to provide reference for similar engineering problems. 
  
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• Research on Temperature Characteristics of PN Junction Capacitance of Bipolar Transistor
• Wen Shulai, Zhang Lei, Yu Shuyong, Lu Jiang
• 2023 Vol. 20 (8): 101-106. DOI:10.3969/j.issn.1673-4440.2023.08.019
• Abstract ( ) PDF (1887KB)( )
• In this paper, taking a commonly-used model of bipolar junction transistor as an example, the patterns of the eff ect of environmental temperature on the PN junction capacitance are investigated based on the signal features of track circuit systems. The results show that the PN junction capacitance between the base and emitter has the same variation trend as the PN junction capacitance between the base and collector. This means that as the external electric field rises, the value of the PN junction capacitance also increases, changing from barrier  to diff usion capacitance. The PN junction capacitance decreases as the temperature increases when the external electric fi eld is higher than built- in fi eld. However, when the external fi eld is lower than built-in fi eld, the PN junction capacitance increases as the temperature rises. The study result is valuable to device selection, maintenance and fault analysis in practical engineering. 
  
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• Analysis of Infl uencing Factors of PCB Current Carrying Capacity
• Niu Yingcong
• 2023 Vol. 20 (8): 107-111. DOI:10.3969/j.issn.1673-4440.2023.08.020
• Abstract ( ) PDF (1494KB)( )
• This paper mainly introduces the important factors aff ecting the PCB current carrying capacity: copper thickness, temperature rise, trace width, trace positioning and other conditions that can change the current carrying capacity, and analyzes the infl uence of each factor on the change of PCB current carrying capacity. By controlling a single variable at a time, it studies the changes in such capacity so as to choose the appropriate board parameters for the printed boards, which makes PCB design more reasonable. According to the research results, the PCB parameters of ZPW•F-K transmitters are calculated to confi rm that the selection 
  of transmitter parameters meet the design requirements. 
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