RTRI was involved in approximately 300 research themes in the fiscal year 2018 to 2019. Among them, 48 were related to rolling stock technology, covering a wide range of themes, in practical, applied and fundamental research, such as: the increase in train running speed and improvement of ride comfort, applied research such as running stability and reliability of rolling stock, and elucidation of the mechanisms leading to wheel wear. The three topics from amongst this research and described in this paper are: "Evaluation of bogie hunting stability," "Active bogie frame steering system ensuring both running stability and curving performance," and "Technique for predicting bogies vibration according to running conditions based on the transfer characteristics between axle boxes and evaluated Points."

Three current focal areas of research at RTRI aim to make railways more sustainable:

(1) Labor-saving and automation of track maintenance in order to counter the effects of an expected fall in the number of experienced engineers and growing labor shortages, by engaging in basic and applied R&D on the utilization of information and communication technology for track maintenance.

(2) Rail maintenance and management: with particular emphasis on rail corrugation, with a view to proposing fundamental countermeasures within the next few years, based on understanding the underlying mechanisms behind the problem.

(3) Development of track technology for regional railways: development of lower cost track improvement methods, in order to drastically improve the LCC of regional railways within the allowable range of public economic support for railway services.

The Human Science Division of the Railway Technical Research Institute in Japan, has been conducting research into education and training aimed at preventing human error, providing driver support and improving car interiors and station environments, in order to improve the safety, convenience and comfort of railways. This paper outlines the recent topics on the fundamental research based on the current issues of the railway and new technological trends.

The critical wind speed of overturning obtained by RTRI's detailed equation tends to be lower than the empirically estimated speed, because it assumes the superposition of the worst conditions. In order to improve the accuracy of the evaluation, previous research has focused on the evaluation of aerodynamic forces that have the greatest influence on calculation results. Only few studies however, have been conducted on the lateral vibrational inertia force. Therefore, in order to evaluate the critical wind speed of overturning reflecting real conditions, an examination was made of the evaluation method based on the measured values of the lateral vibrational acceleration.

This paper describes the development of a bogie equipped with a new type of tilt mechanism capable of providing a tilt of up to 5 degrees which is the same maximum tilt angle as the conventional bolster-type tilt mechanism, though with simpler structure. The tilt mechanism proposed provides the tilting forces to the carbody by adding torsional torque to the torsion bar on the anti-rolling device. The rotary actuator, which is inserted between the torsion bar and the arm in series, generates the torsional torque. The arms and the vertical links transmit the torque to the carbody. A bench test for simulating running on a curve and carbody tilting was conducted. The results demonstrate that it is possible to tilt the carbody with high responsiveness according to the target tilt pattern up to 5 degrees.

Much research on detecting machinery faults in the early stage is being conducted for the purpose of preventing failure and reducing maintenance effort simultaneously. In this paper, a bearing fault detection method for a railway traction motor through leakage currents is proposed. The proposed detection method combines octave band analysis and machine learning. Experiments simulating abnormalities due to defective bearings were conducted and the effectiveness of the proposed method was verified. These experiments showed that the proposed method can successfully detect failures in railway traction systems in relation to specific conditions and that leakage current could potentially be used to detect bearing faults.

A hazard sensing technology has been developed for track maintenance that can extract hazard factors related to the expansion of the damage caused by a derailment accident. In addition, a risk-based maintenance method was developed for track irregularity management using the hazard sensing results and a statistical risk model. As a result, it is now possible to extract the factor of magnification of derailment damage (collision with structures and the public, falls from elevated locations) through image analysis using images recorded from the front of commercially operated trains. In addition, a maintenance and management model was created to calculate the appropriate values of the management value of track irregularity and the inspection cycle time, considering the track maintenance cost and the damage scale of the derailment accident.

In Japan, turnout structures are usually designed on the basis of verified experience or JIS specifications. Consequently, there is no established method yet for evaluating original turnout structures. This study examines an evaluation method for turnout structures based on dynamic analyses. When considering new turnout structures, it is necessary to carry out evaluations of running safety and track material strength. In order to implement them efficiently, it was decided to evaluate them separately.

Rail breakages due to transverse cracks originating from gauge corner cracks have been occurring in heat-treated rails. Railway Operators conduct periodic maintenance by replacing rails, through visual inspection and rail ultrasonic flaw detection. These measures represent a significant cost, creating the need for research on crack propagation. As part of this research, rail bending tests were carried out on rails which have been given artificially introduced cracks on the rail head, to investigate the transverse crack growth rate. In addition, a method was developed for estimating transverse crack growth using FEM. This method was verified by comparing estimated values with actual rail bending test results.

The purpose of this research is to identify situations where a driver is unable to perform tasks properly because of psychological stress, etc., and devise means to help them. Basic research began with the aim of developing a technology to gauge the mental state of without relying on subjective evaluation of drivers, such as physiological indices and behavioral data. A system that can measure various physiological and behavioral data including electroencephalograms (EEG) was constructed. As a result of experimenting with the system, it was found that the occurrence and recovery of psychological sway appeared in physiological changes such as EEG and pupil diameter.

The purpose of this study is to investigate visual-searching behaviors that are effective for recognizing the extraordinary events based on the eye movements of railway drivers. Track subsidence ahead of drivers was set as an extraordinary event. Two driving scenarios were associated with this extraordinary event, namely high velocity (approximately 90 km/h) and low velocity (approximately 15 km/h). In the high velocity driving scenario, drivers that maintained a longer gaze during each visual search recognized the subsidence easily. In the low velocity driving scenario, drivers that had a wider gazing angle in the horizontal direction during each visual search recognized the subsidence easily.

It is of vital importance to enhance on-board passenger safety in the event of a train collision. In order to design the interior fittings to reduce passenger injury levels, it is necessary to examine the probability of such injuries. The purpose of this study is to grasp the severity of injuries suffered by occupants of longitudinal seats and to consider mitigation measures using FEM simulation. For this simulation, bench-end partitions were modeled on the basis of an FEM model. It was found that passengers seated on a longitudinal seat with a high risk of injury were those seated second-furthest and third-furthest away from the bench-end partition and that the severity of head injury decreased significantly with the presence of handrails.