Major Results of Research and Development in Fiscal 2017
This publication is a collection of the major results obtained from research undertaken by the Japanese public body, the Railway Technology Research Institute, in 2017.
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
- A simulator was built to be able to estimate the behavior of railway structures, electric poles and railway vehicles during earthquakes.
- A self-correcting function for input parameters corresponding to observed ground motions and railway damage data was added.
- A simulator makes it possible to reduce the time required to resume railway services after an earthquake by ranking structures in order of priority for inspection.
- An earthquake early warning method utilizing ocean bottom seismometer data was developed, to which observation data was applied to investigate the suitability of the specified values used in the method and its effectiveness in preventing false alerts.
- This method is expected to be able to generate warnings 10 secs earlier than with the previous method for subduction-zone earthquake.
- The mechanisms of ballasted track buckling during earthquakes resulting from subsidence of abutment backfill, were clarified.
- A countermeasure to prevent buckling was proposed, consisting of an integrated ballast retaining wall and contiguous pile wall for reinforcing the abutment backfill.
- A method for testing soil deformation characteristics was developed for conducting dynamic ground response analyses.
- A hybrid ground response testing device was developed in order to take into account ground including unusual soil.
- The proposed method can contribute to seismic design for railway structures and assessing soil liquefaction potential.
- An anti-seismic reinforcement method was developed for suspended ceilings with small spaces at stations, using square pipes.
- Structural tests demonstrated the strong anti-seismic reinforcement performance of this method.
- This technique could reduce costs to less than half of that for existing methods.
- An algorithm has been created to estimate strong wind areas due to gusts etc., based on meteorological radars.
- The algorithm can predict strong wind areas due to gusts up to 10 minutes ahead, at 5 minute intervals.
- A decision-making flowchart was proposed for determining if a bridge can be reused after scouring damage.
- This method shortens traffic downtime and contributes to improving the resilience of the railways.
- It has been clarified that bogie hunting is caused by a combination of running speed and lateral displacement of the wheelset..
- It is now possible to accurately evaluate running stability through a test method.
- A method has been developed for projecting images onto a monitor of outside views a driver cannot see from the driving cab due to lines of vision obstructed by parts of the driving cab, in a way which appears natural to the driver.
- This equipment will alleviate driver load as a visual support.
- Using an invisible ray laser Doppler vibrometer, it is possible to determine the overall health of an entire structure from a distance of 300m.
- The laser’s automatically controlled scanner allows the device to detect the points on the target surface which can offer the highest level of measurement accuracy.
- Using simultaneous measurements made from two devices it is possible to measure the natural frequency of a continuous viaduct remotely.
- The change in pinion bearing endplay due to the temperature variations of the pinion and its peripheral parts was clarified.
- Assembly methods capable of not reducing the endplay to near 0 mm during the shaft rotation, and structures capable of eliminating the adjustment of the endplay, were found to be effective in preventing pinion bearing seizure.
12. Development of early restoration and reinforcement technologies for embankments damaged by natural disasters
- A effective method for rapidly restoring and reinforcing embankments damaged by severe weather events, using a combination of earth bank reinforcing materials, gabions and drainage pipes has been developed, and an accompanying design and work manual has been drafted.
- The proposed restoration method increases resistance to rain damage 1.7 times and 1.5 times to earthquakes.
- The proposed method can reduce work time by approximately 30%.
- An improved performance rock bolt was developed that is effective even in loosened ground.
- Test work confirmed that the new design was workable and maintained axial force over the long term.
- Compared to existing rock bolts, the new design can reduce work related costs by about 40%.
- A simple catenary has been developed with fewer components and good maintainability for lines with running speeds of over 300km/h.
- Tests on a revenue line confirmed that the contact loss ratio and contact wire uplift were both within admissible limits, and that the new design posed no problem for the current collecting function of the new system.
- A system has been developed to optimize five-year maintenance plans for track irregularity and ballast replacement.
- This system makes it possible to decide track irregularity maintenance and ballast replacement plans that reduce the total cost of maintaining tracks to a satisfactory level over the medium term.
- An automatically controlled hot rail correcting machine was developed as a rail head defect repair method.
- The new machine can reduce working time by 2/3 compared to existing methods, to within three hours.
- In order to generalize the use of this method, a “Working handbook” was compiled.
- A train control system has been developed, designed for regional railways using wireless communication which does not require track circuits and wayside signals in station yards.
- Trains are protected when running from one station to the next by an onboard device installed with a database.
- Since a generic wireless LAN is used, and IP telephone connection can be used for ground facility-train communication
- A method to synthesize hydrogen-ion type geopolymer with a high-performance concrete deterioration inhibitory effect has been developed.
- The new compound is as effective against ASR concrete deterioration as existing lithium based products, for one-fifth of the material cost.
Ⅲ.Harmonization with the Environment
- A DC feeding voltage control technology has been developed to allow more efficient use of regenerative electric power.
- With the new technique, voltage can be controlled to within approximately 25% of the rated value, whilst the cost is about 20% of the latest existing technology.
20. Model for predicting wayside noise considering sound reflection from structures close to the railway track
- A model for predicting wayside noise has been designed which takes into account the influence of sound reflected or shielded by cut slopes, overpasses and other buildings.
- This model can be applied for investigating noise control for complex situations, for example if a new building or overpass has been constructed adjacent to railway tracks.
Ⅳ.Improvement of Convenience
- An active bogie angle steering system has been developed which can reduce the yawing moment of a bogie by 77% and the average lateral force by 56% in curved sections.
- The new system includes a robust failsafe function, and can be fitted onto existing vehicles.
22. Improvement of the effectiveness of tunnel entrance hoods by enlargement of their cross-sectional area to reduce micro-pressure waves
- A cross-sectional area ratio of the tunnel entrance hood to the main tunnel has been proposed which is effective in reducing micro-pressure waves.
- It has been found that if the tunnel-entrance-hood-to-main-tunnel cross-section ratio is increased to 2.5, the hood will still be effective in reducing micro-pressure waves even if all side-wall openings are closed, and the hood is less than 40m. It was also found that for cases where the extension is over 40m, a graduated increase in the cross-sectional area ratio of the tunnel entrance hood to the main tunnel is also effective.
23. Communication network and train operation simulator for designing train control system using radio communication
- A simulator was developed to evaluate train delays and stability of the train control system using radio communication.
- The simulator will help to reduce the cost of designing radio communication networks and also satisfy the requirement of ensuring transmission quality and recovery from train delays.
24. Method for supporting decisions on planning Shinkansen transport services based on forecast demand fluctuations
- A method to forecast half-hourly demand fluctuations on a daily basis was developed based on past actual Shinkansen ridership records, calendar arrays and large events scheduled to be held near stations.
- With the developed decision-making support system for planning Shinkansen transport services, it is possible to determine the need to operate or not daily pre-planned extra trains based on the result of demand fluctuation forecasts.
- A method has been proposed for measuring dynamic deformation on the friction surface of brake discs heated to high temperature during high speed rotation, which up until now has been difficult to do.
- Better understanding of the dynamic deformation of the disc and the pad can be used for verifying their design and examining relevant mechanisms.
- A current collection HILS system was developed which enables simulated running tests to be conducted using stationary pantographs to examine the interaction between pantographs and overhead contact lines.
- Verifications were made to check that the system was able to reproduce OCL vibrations up to 20 Hz generated at running speeds of 300 km/h by the span length between support points and distance between droppers.
- The HILS system could reduce the time required to develop new pantograph designs.
- Based on an analysis of airflows around a railway vehicle including the bogie, it was possible to reproduce the meandering airflows occurring underneath the carbody.
- Comparison of calculated airflows and wind tunnel test results showed that the tendencies in power spectra for lateral airflow velocity fluctuations between the two were almost identical.
- The results of this work can be used to examine measures for reducing train oscillation in tunnels.
28. Wind tunnel tests reproducing the wind force resulting from natural wind and vehicle velocity to evaluate aerodynamic forces acting on railway vehicles
- In order to evaluate the effect of wind force resulting from natural wind and vehicle velocity, a wind tunnel test method was developed to evaluate the aerodynamic forces exerted on a moving vehicle model.
- It was found that on flat ground and on top of embankments, the influence of running on the side force coefficient is small, and it is therefore possible to evaluate the performance of a railway vehicle in resistance to overturning in windy conditions by using a static train model.
- A measuring method for detecting the sources of aerodynamic noise from bogies was developed using a “sound transmission plate”
- It was found that the main sources of aerodynamic noise were the traction motor and the gear unit.
- This method will now allow the reduction of the aerodynamic bogie noise more efficiently.
- It is now possible to objectively monitor changes in the physiological state of drivers as they carry out their driving tasks, based on simultaneous measurement of various physiological indices using high performance multipoint electroencephalographs etc.
- By combining various physiological indices, it is possible to detect moments of concentration or psychological upset.
- A multi-segment pantograph head has been proposed which not only produces less noise but also offers high compliance to contact wire fluctuation .
- Compared to a conventional type pantograph head fitted with flexible contact strip support, tests confirmed that the multi-segment panhead had ten times more compliance and a 50% lower contact loss ratio.
・Ⅰ.1, Ⅰ.7, Ⅰ.10, Ⅱ.13 received funding from the Ministry of Land, Infrastructure, Transport and Tourism.
・Ⅰ.2 is collaborative research with National Research Institute for Earth Science and Disaster Resilience.
・Ⅰ.3 is collaborative research with Yokohama National University.
・Ⅰ.6 is collaborative research with Kochi University.
・Ⅱ.12 is collaborative research with Raito Kogyo Co., Ltd., OKASAN LIVIC Co., Ltd., and Koiwa Kanaami Co., Ltd..
・Ⅴ.26 is collaborative research with University of Bristol.
・Ⅴ.30 is collaborative research with Keio Gijuku.