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Major Results of Research and Development in Fiscal 2024

This publication is a collection of the major results obtained from research undertaken by the Japanese public body, the Railway Technology Research Institute, in 2024. We would like to take this opportunity to thank all JR companies in particular and all the research centers, universities, industrial partners and other entities which have offered their cooperation, commitment and support to achieve these results and without whom none of this work would have been possible.

Ⅰ. Improvement of Safety

1. Performance Evaluation Method for Earthquake Early Warning Systems

  • We have developed a performance evaluation method and simulator for earthquake early warning systems that can quantitatively assess the implementation effects and the transportation impact due to a new earthquake early warning.
  • The results of the performance evaluation can be used to support decision-making when implementing a new warning method into an earthquake early warning system.

  • We have developed a performance evaluation method and simulator for earthquake early warning systems that can quantitatively assess the implementation effects and the transportation impact due to a new earthquake early warning.
  • The results of the performance evaluation can be used to support decision-making when implementing a new warning method into an earthquake early warning system.

2. Method for Setting Regulation Values for Operation Control Under Rainfall Using Radar Rain Gauges

  • We have proposed a method for setting regulation values for operation control under rainfall using radar rain gauges by converting the regulation values of existing railway rain gauges.
  • Although the regulation time increases slightly, more disaster events are captured, leading to improved safety.

  • We have proposed a method for setting regulation values for operation control under rainfall using radar rain gauges by converting the regulation values of existing railway rain gauges.
  • Although the regulation time increases slightly, more disaster events are captured, leading to improved safety.

3. Method for Estimating Track Buckling Risk Based on On-board Measurements

  • We have developed a method to estimate the lateral ballast resistance using the gap between a sleeper and a ballast estimated from track measurements and ballast shape data obtained by on-board LiDAR.
  • We have developed a system that identifies locations with potential risk of buckling on the track maintenance management database by using the estimated lateral ballast resistance and the maximum track curvature.

  • We have developed a method to estimate the lateral ballast resistance using the gap between a sleeper and a ballast estimated from track measurements and ballast shape data obtained by on-board LiDAR.
  • We have developed a system that identifies locations with potential risk of buckling on the track maintenance management database by using the estimated lateral ballast resistance and the maximum track curvature.

4. Method for Identifying Wheel Usage Limit Temperature and Evaluating Safety While in Service

  • We have developed a method to identify the safety limit temperatures for various types of wheels when abnormal overheating occurs and to easily estimate the resulting residual stresses based on the deformation amount specific to each wheel type.
  • As a more accurate method to assess wheel safety while the vehicle is in service, we have developed a residual stress estimation technique using an ultrasonic measurement device.

  • We have developed a method to identify the safety limit temperatures for various types of wheels when abnormal overheating occurs and to easily estimate the resulting residual stresses based on the deformation amount specific to each wheel type.
  • As a more accurate method to assess wheel safety while the vehicle is in service, we have developed a residual stress estimation technique using an ultrasonic measurement device.

5. Investigation of Front Rod Fracture Causes and Maintenance Methods to Prevent Fracture

  • We have identified the causes of fractures of front rods, which are part of the switch and lock movement, through both experiments and analysis, and found that they are caused by impacts during vehicle passage and improper lateral length adjustment.
  • We have proposed inspection items, adjustment methods, and evaluation criteria necessary to prevent fractures of front rod L type connection devices during inspections conducted by railway operators.

  • We have identified the causes of fractures of front rods, which are part of the switch and lock movement, through both experiments and analysis, and found that they are caused by impacts during vehicle passage and improper lateral length adjustment.
  • We have proposed inspection items, adjustment methods, and evaluation criteria necessary to prevent fractures of front rod L type connection devices during inspections conducted by railway operators.

6. Detection System for DC High-resistance Ground Faults by Utilizing the Current Data of Both Substations and Vehicles

  • We have developed a system capable of detecting high-resistance ground faults by utilizing the current data of both substations and vehicles simultaneously, while taking into account the position of trains within the feeding sections.
  • The system is compatible with configurations involving multiple trains and multiple feeding section, and is capable of detecting ground faults of several hundred amperes that are difficult to detect with conventional protection systems.

  • We have developed a system capable of detecting high-resistance ground faults by utilizing the current data of both substations and vehicles simultaneously, while taking into account the position of trains within the feeding sections.
  • The system is compatible with configurations involving multiple trains and multiple feeding section, and is capable of detecting ground faults of several hundred amperes that are difficult to detect with conventional protection systems.

7. Forward Obstacle Detection System for Trains in Preparation for Future Driverless Operation

  • We have developed a forward obstacle detection system for trains in preparation for future driverless operation on lines with level crossings and similar features.
  • Using railway-specific information for calibration, high-precision sensor fusion of multiple sensors can be achieved without the need for special adjustments.

  • We have developed a forward obstacle detection system for trains in preparation for future driverless operation on lines with level crossings and similar features.
  • Using railway-specific information for calibration, high-precision sensor fusion of multiple sensors can be achieved without the need for special adjustments.

8. Validation of the Long-term Effectiveness of Automatic Deerdeterrent Sound Devices

  • The installation of automatic deer-deterrent sound devices was found to reduce collisions between trains and deer by approximately 30 to 40%, and this reduction was confirmed to be statistically significant.
  • A validation test conducted over 2 years and 9 months confirmed that the above effect is sustained over the long term.

  • The installation of automatic deer-deterrent sound devices was found to reduce collisions between trains and deer by approximately 30 to 40%, and this reduction was confirmed to be statistically significant.
  • A validation test conducted over 2 years and 9 months confirmed that the above effect is sustained over the long term.

Ⅱ. Cost Reduction

9. Design Method for Post-installed Anchor Joint Members in the Reconstruction of Concrete Structures

  • We clarified the stiffness and capacity of the joint surface according to the quantity and drilling positions of post-installed anchors, as well as the shear transfer capacity based on the treatment method of the joint surface, and developed a design method for joint members.
  • Compared to conventional methods, the amount of post-installed anchors can be reduced by approximately 30%, making construction and quality assurance easier for existing structures with overcrowded reinforcement.

  • We clarified the stiffness and capacity of the joint surface according to the quantity and drilling positions of post-installed anchors, as well as the shear transfer capacity based on the treatment method of the joint surface, and developed a design method for joint members.
  • Compared to conventional methods, the amount of post-installed anchors can be reduced by approximately 30%, making construction and quality assurance easier for existing structures with overcrowded reinforcement.

10. Reinforcement Method for Preventing Fatigue Cracks at Steel Girder Support Sections

  • We have developed a reinforcement method that prevents fatigue crack occurrence at steel girder support sections without the need for temporary girder supports.
  • By driving in bearing bolts to press the backing plate against the bottom flange, the plate efficiently shares the load, reducing stress concentration at the lower end of the edge stiffener where fatigue cracks tend to initiate.
  • This reinforcement method can be implemented in a short time at less than 10% of the cost of conventional methods.

  • We have developed a reinforcement method that prevents fatigue crack occurrence at steel girder support sections without the need for temporary girder supports.
  • By driving in bearing bolts to press the backing plate against the bottom flange, the plate efficiently shares the load, reducing stress concentration at the lower end of the edge stiffener where fatigue cracks tend to initiate.
  • This reinforcement method can be implemented in a short time at less than 10% of the cost of conventional methods.

11. Method for Identifying Potentially Critical Locations of Loose Bearing Based on On-board-measured Track Geometry

  • We have developed a method for identifying bridge loose bearing locations by utilizing the difference between track geometry measured under loaded conditions obtained from a track inspection car and track geometry measured under unloaded conditions obtained from a simplified track measurement device.
  • This method enables the high-accuracy identification of loose bearing locations with vibration or with an uplift gap of 0.5 mm or more in sections where steel bridges with ballastless tracks are continuous.

  • We have developed a method for identifying bridge loose bearing locations by utilizing the difference between track geometry measured under loaded conditions obtained from a track inspection car and track geometry measured under unloaded conditions obtained from a simplified track measurement device.
  • This method enables the high-accuracy identification of loose bearing locations with vibration or with an uplift gap of 0.5 mm or more in sections where steel bridges with ballastless tracks are continuous.

12. Extension of Rail Replacement Cycles Considering Fatigue/Soundness

  • Fatigue tests conducted on rails that had reached their replacement cycles while remaining in sound condition revealed little to no reduction in fatigue strength, indicating that periodic replacement may no longer be necessary.
  • To identify locations where rail defects are likely to occur, we have developed a method for evaluation of health using track measurement data and implemented it in the track maintenance management database system.

  • Fatigue tests conducted on rails that had reached their replacement cycles while remaining in sound condition revealed little to no reduction in fatigue strength, indicating that periodic replacement may no longer be necessary.
  • To identify locations where rail defects are likely to occur, we have developed a method for evaluation of health using track measurement data and implemented it in the track maintenance management database system.

13. Support Method for Extending Inspection Periods Based on Statistical Analysis of Equipment Inspection Records

  • We have developed a statistical framework to estimate the relationship between service life and failure occurrence rate, considering heterogeneity among individual equipment, based on equipment inspection records and ledger data.
  • We have proposed an approach to optimizing inspection periods based on failure occurrence rates, and applied to support a railway operator’s decision-making to extend the period for point machines on a certain actual railway section from three months to four months.

  • We have developed a statistical framework to estimate the relationship between service life and failure occurrence rate, considering heterogeneity among individual equipment, based on equipment inspection records and ledger data.
  • We have proposed an approach to optimizing inspection periods based on failure occurrence rates, and applied to support a railway operator’s decision-making to extend the period for point machines on a certain actual railway section from three months to four months.

14. Automated Visual Inspection System for Vehicle Underbody

  • We have developed a system that captures high-resolution continuous images of the underbody of passing vehicles and diagnoses any external abnormalities, replacing manual visual inspection.
  • Recognizing the vehicle number displayed on the carbody from these images eliminates the need for RFID tags and reduces cost.
  • The system enables high-frequency inspections outdoors regardless of the time of day or weather conditions.

  • We have developed a system that captures high-resolution continuous images of the underbody of passing vehicles and diagnoses any external abnormalities, replacing manual visual inspection.
  • Recognizing the vehicle number displayed on the carbody from these images eliminates the need for RFID tags and reduces cost.
  • The system enables high-frequency inspections outdoors regardless of the time of day or weather conditions.

15. Autonomous Train Operation System

  • We have developed an autonomous train operation system that enables trains to make operation decisions and control point machines & level crossings autonomously, based on the status information on railway tracks and along waysides.
  • In the future, this system has the potential to reduce labor and manpower across the entire train operation process, including driving, maintenance, and traffic control.
  • Sharing information through the Railway Dynamic Map can be effectively used to enhance traffic control.

  • We have developed an autonomous train operation system that enables trains to make operation decisions and control point machines & level crossings autonomously, based on the status information on railway tracks and along waysides.
  • In the future, this system has the potential to reduce labor and manpower across the entire train operation process, including driving, maintenance, and traffic control.
  • Sharing information through the Railway Dynamic Map can be effectively used to enhance traffic control.

16. General Purpose Real-time Algorithm for Generating Driving Curves for Driver Advisory System

  • We have developed a real-time algorithm for generating driving curves for driver advisory system that can be applied to various types of trains and railway routes.
  • We have confirmed that the driving method to achieve on-time operation is presented within a short time.
  • The algorithm was validated across numerous railway routes and trains, receiving generally favorable evaluations from train drivers.

  • We have developed a real-time algorithm for generating driving curves for driver advisory system that can be applied to various types of trains and railway routes.
  • We have confirmed that the driving method to achieve on-time operation is presented within a short time.
  • The algorithm was validated across numerous railway routes and trains, receiving generally favorable evaluations from train drivers.

17. Method for Updating On-board Databases Using Public Communication Networks

  • The update of on-board databases for train control, which was previously performed manually by staff for each vehicle, can now be automated, enabling significant time reduction and labor-savings in the update process.
  • Since updates can be performed even while the train is stopped at a station, it becomes easier to introduce on-board database-based train protection systems on through service lines where diverse vehicles are running.

  • The update of on-board databases for train control, which was previously performed manually by staff for each vehicle, can now be automated, enabling significant time reduction and labor-savings in the update process.
  • Since updates can be performed even while the train is stopped at a station, it becomes easier to introduce on-board database-based train protection systems on through service lines where diverse vehicles are running.

18. Labor-saving for Generating Crew Schedule to Enable Workforce Efficiency and Reduce Labor Burden

  • We have developed a method for automatically generating crew schedules that balance workforce efficiency and labor burden reduction, specifically for train timetable revisions.
  • The method can generate crew schedules in approximately five hours even for high-density lines with over 500 trains per day, resulting in labor-saving in the planning process.

  • We have developed a method for automatically generating crew schedules that balance workforce efficiency and labor burden reduction, specifically for train timetable revisions.
  • The method can generate crew schedules in approximately five hours even for high-density lines with over 500 trains per day, resulting in labor-saving in the planning process.

Ⅲ. Harmonization with the Environment

19. Two-Step Cross-Sectional Tunnel Entrance Hood

  • As an effective tunnel entrance hood extension for reducing micro-pressure waves, we proposed a twostep cross-sectional tunnel entrance hood with an extended section that has a larger cross-sectional area than the existing section.
  • Field measurements were conducted in a tunnel equipped with the two-step cross-sectional tunnel entrance hood, confirming that the micro-pressure waves did not worsen compared to the current condition before and after the speed increase.

  • As an effective tunnel entrance hood extension for reducing micro-pressure waves, we proposed a twostep cross-sectional tunnel entrance hood with an extended section that has a larger cross-sectional area than the existing section.
  • Field measurements were conducted in a tunnel equipped with the two-step cross-sectional tunnel entrance hood, confirming that the micro-pressure waves did not worsen compared to the current condition before and after the speed increase.

20. Method for Detailed Prediction of Contribution of Each Noise Source on Wayside Noise Generated by Shinkansen Vehicles

  • We developed a method for predicting wayside noise at an evaluation point 25 m away from the center of the nearest track by using high-resolution measured noise source distributions around vehicles and applying sound propagation characteristics of point source.
  • Since the method enables the calculation of the detailed contribution ratio of each noise source at the evaluation point, it allows for the prediction of the noise when modifying the shape of specific vehicle components or changing the height of noise barriers.

  • We developed a method for predicting wayside noise at an evaluation point 25 m away from the center of the nearest track by using high-resolution measured noise source distributions around vehicles and applying sound propagation characteristics of point source.
  • Since the method enables the calculation of the detailed contribution ratio of each noise source at the evaluation point, it allows for the prediction of the noise when modifying the shape of specific vehicle components or changing the height of noise barriers.

21. Integrated Control Method for Railway Energy Storage Systems Enabling the Use of Renewable Energy

  • We have developed an algorithm that integrally controls the charge/discharge of both stationary and on-board energy storage systems in order to enable the stable use of fluctuating renewable energy.
  • We have implemented the control function of the on-board energy storage system based on charge/ discharge demands at an in-house test track, and demonstrated that it is possible to utilize both regenerative energy and renewable energy.

  • We have developed an algorithm that integrally controls the charge/discharge of both stationary and on-board energy storage systems in order to enable the stable use of fluctuating renewable energy.
  • We have implemented the control function of the on-board energy storage system based on charge/ discharge demands at an in-house test track, and demonstrated that it is possible to utilize both regenerative energy and renewable energy.

22. Development and Commercial Operation Demonstration of High-capacity Superconducting Feeding for Urban Commuter Lines

  • We have developed a high-capacity superconducting feeding system for urban commuter lines.
  • Demonstration tests on actual railway lines confirmed that the system can suppress voltage drops even under a high-density timetable, enabling electric power transmission to commercial trains with stability.
  • The superconducting feeding system enables a reduction in substation load and a decrease in the number of substations.

  • We have developed a high-capacity superconducting feeding system for urban commuter lines.
  • Demonstration tests on actual railway lines confirmed that the system can suppress voltage drops even under a high-density timetable, enabling electric power transmission to commercial trains with stability.
  • The superconducting feeding system enables a reduction in substation load and a decrease in the number of substations.

23. Safety Assessment of Hydrogen Fuel Cell Multiple Units

  • For the social implementation of hydrogen fuel cell multiple units we have conducted a risk assessment and proposed safety measures including leak and pressure sensor, safety valves and shut-off valves, as well as structural protections.
  • In particular, we conducted simulations to verify safety regarding small leaks from rooftop equipment piping and large releases from thermal safety valves during fires inside tunnels.

  • For the social implementation of hydrogen fuel cell multiple units we have conducted a risk assessment and proposed safety measures including leak and pressure sensor, safety valves and shut-off valves, as well as structural protections.
  • In particular, we conducted simulations to verify safety regarding small leaks from rooftop equipment piping and large releases from thermal safety valves during fires inside tunnels.

Ⅳ. Improvement of Convenience

24. Automatic Pantograph Drop System Using Real-time Abnormality Detection in the Current Collection System

  • We have developed a system that detects pantograph part detachments and foreign objects attached to the overhead contact line in real time using camera images and automatically lowers the pantograph when abnormalities are detected.
  • This system helps prevent a chain of equipment damage caused by the current collection system, thereby reducing downtime.

  • We have developed a system that detects pantograph part detachments and foreign objects attached to the overhead contact line in real time using camera images and automatically lowers the pantograph when abnormalities are detected.
  • This system helps prevent a chain of equipment damage caused by the current collection system, thereby reducing downtime.

25. Development of a Low-cost Primary and Secondary Vertical Semi-active Suspension System

  • We have developed a system that achieves high vibration reduction performance at low cost by designing variable dampers suitable for mass production and optimizing the combination and placement of sensors used.
  • This system is suitable for reducing vertical and roll vibrations of high-speed Shinkansen trains, thereby improving ride comfort.
  • In vibration excitation tests simulating actual running, we confirmed the system’s effectiveness in improving ride comfort.

  • We have developed a system that achieves high vibration reduction performance at low cost by designing variable dampers suitable for mass production and optimizing the combination and placement of sensors used.
  • This system is suitable for reducing vertical and roll vibrations of high-speed Shinkansen trains, thereby improving ride comfort.
  • In vibration excitation tests simulating actual running, we confirmed the system’s effectiveness in improving ride comfort.

26. Thermal Comfort Evaluation Method Using Air Conditioning Log Data from Commuter Trains

  • We have proposed a method to evaluate thermal comfort by utilizing existing air conditioning log data.
  • We have conducted thermal sensation surveys inside operating trains during summer and winter, and confirmed that the comfort evaluations using the proposed method closely matched the actual evaluations.
  • The method is able to detect hot or cold conditions inside the train and be used to examine measures for improving air conditioning control.

  • We have proposed a method to evaluate thermal comfort by utilizing existing air conditioning log data.
  • We have conducted thermal sensation surveys inside operating trains during summer and winter, and confirmed that the comfort evaluations using the proposed method closely matched the actual evaluations.
  • The method is able to detect hot or cold conditions inside the train and be used to examine measures for improving air conditioning control.

Ⅴ. Basic Research

27. Method for Estimating the Density of Newly Fallen Snow Using Dual-polarization Radar

  • We have developed a method that uses dual-polarization radar to estimate the density of newly fallen snow according to the snowfall types, such as aggregate or graupel, which could not be distinguished by conventional methods using air temperature.
  • Our method can improve the accuracy of avalanche risk assessment, snowfall depth on railway tracks, and the amount of snow accretion under vehicle floors.

  • We have developed a method that uses dual-polarization radar to estimate the density of newly fallen snow according to the snowfall types, such as aggregate or graupel, which could not be distinguished by conventional methods using air temperature.
  • Our method can improve the accuracy of avalanche risk assessment, snowfall depth on railway tracks, and the amount of snow accretion under vehicle floors.

28. Prediction Method for Long-term Deformation Behavior of Concrete Bridges Considering Water Content Conditions

  • We have developed a program that analyzes shrinkage strain based on water content conditions and mix proportions using information available in practical applications, and proposed a method to predict the long-term deformation behavior of concrete bridges.
  • This advancement in design methods for long-term deformation of concrete bridges is expected to be utilized for designs that control the effects of shrinkage, addressing issues such as track irregularities caused by deflection.

  • We have developed a program that analyzes shrinkage strain based on water content conditions and mix proportions using information available in practical applications, and proposed a method to predict the long-term deformation behavior of concrete bridges.
  • This advancement in design methods for long-term deformation of concrete bridges is expected to be utilized for designs that control the effects of shrinkage, addressing issues such as track irregularities caused by deflection.

29. Non-contact Disc Brake Enabling Power Regeneration in Trailers

  • To pursue energy saving, reduced maintenance, and reduced consumable parts in railway vehicles, we have proposed a non-contact disc brake capable of power regeneration in trailers.
  • We have demonstrated that power regeneration can be achieved with a simple circuit using resonance phenomenon between an electromagnet and a capacitor, without the need for an inverter.

  • To pursue energy saving, reduced maintenance, and reduced consumable parts in railway vehicles, we have proposed a non-contact disc brake capable of power regeneration in trailers.
  • We have demonstrated that power regeneration can be achieved with a simple circuit using resonance phenomenon between an electromagnet and a capacitor, without the need for an inverter.

30. Method for Reducing Unstable Vibrations of Pantographs Caused by Sliding Friction

  • We have clarified that the mechanism causing unstable pantograph vibrations is a phenomenon that occurs when vertical and longitudinal natural modes of vibrations come close and amplify each other under conditions of a high coefficient of friction.
  • We have proposed a method to evaluate the proximity and amplification of natural modes to reduce unstable vibrations.
  • This method enables the design of pantographs that can slide with stability.

  • We have clarified that the mechanism causing unstable pantograph vibrations is a phenomenon that occurs when vertical and longitudinal natural modes of vibrations come close and amplify each other under conditions of a high coefficient of friction.
  • We have proposed a method to evaluate the proximity and amplification of natural modes to reduce unstable vibrations.
  • This method enables the design of pantographs that can slide with stability.

• 4 includes collaborative research results with Chalmers University of Technology. • 8 includes collaborative research results with Hokkaido Development Engineering Center. • 10 was conducted by collaborative research with Shibaura Institute of Technology and Kawada Industries, Inc. • 12 was conducted by collaborative research with University of Toyama. • 13 was conducted by collaborative research with Shikoku Railway Company and Osaka University. • 18 was conducted by collaborative research with Waseda University. • 22 includes Railway Technology Development Subsidy of Ministry of Land, Infrastructure, Transport and Tourism. • 23 includes contract research results with AIST Solutions Co., Ltd. • 25 was conducted by collaborative research with Astemo, Ltd. • 27 was conducted by collaborative research with Yamaguchi University and Japan Weather Association. • 30 was conducted by collaborative research with Kyushu University.

Major Results of Research and Development