The COVID-19 pandemic continues to have a significant impact on railway business. Although it is still difficult to have a clear vision about a Post-Covid Society will be like for the moment railway services must be more reliable in order to avoid concentrations of passengers due to delays or cancellation of trains. In the longer term, railways must focus on lowering carbon emissions and improving maintenance. To this end, RTRI has been engaged in research to improve the reliability of power supply equipment, to save energy during train operation and to improve maintainability of power supply systems. This paper describes some of the outcomes achieved at RTRI through this recent research.

With the recent developments in information and communication technology (ICT), various research and development projects are ongoing in the world to propose new train control technology for safer and more stable transportation services. These technologies are expected to reduce costs and the number of equipment used for safe train operation.

RTRI has been challenging to develop new technology to realize digitalization of railway systems, and RTRI sets up a new project to accelerate R & D on utilization of ICT from FY2020. This paper introduces the plan for the R & D on the new autonomous train operation control system using ICT in the new master plan of RTRI started from FY 2020, after surveying the R & D that has been undertaken in the previous master plan of RTRI from FY2015 to FY2019.

The Railway Technical Research Institute (RTRI) has been developing "railway simulators" as a common platform for developing advanced railway simulation technology and has successively implemented research projects every five years since 2010. In the last five years (2015-2019), RTRI has developed a "virtual railway test line" and a "coupling environment for individual simulators". The virtual railway test line, which reproduces the dynamic behavior of the railway system during train operation under various conditions, is used to perform virtual running tests. The railway simulator coupling environment, which uses coupled calculations by linking multiple simulators, is used to carry out comprehensive analyses. This report outlines these achievements and introduces future research prospects.

The detection of high-resistance ground faults in DC 1.5 kV traction power supply systems has remained an unresolved problem for years. There are several methods to detect such faults using additional devices and/or wires installed along tracks. However, due to cost and maintenance problems, there has been a demand for a fault detection method which uses only electrical measurements inside traction substations. To this end, we analyzed a recorded current waveform of an actual fault to find out its characteristics. Based on the results obtained, we proposed a novel method for detecting high-resistance ground faults with a discharging arc of more than a thousand amperes DC current.

Chromium-zirconium precipitation-hardened copper alloy (PHC) contact wire was developed for high speed lines to address issues relating to cost and the environment. However, the problem with PHC contact wire is that is not easily produced in small quantities, to meet the demand for small lots from railway operators. Therefore, the authors of this paper developed a new contact wire, Cobalt-phosphorus precipitation-hardened copper alloy (CPS) contact wire which can be produced in smaller quantities. The resulting low-cost CPS contact wire has the same strength and electric conductivity as PHC contact wire. This paper describes results from performance tests conducted with the CPS contact wire.

Simulation of Catenary/Pantograph dynamic interaction is used for understanding the dynamic behavior of overhead contact lines (OCL) and pantographs, and stability to supply electric power to a vehicle. The authors developed a new simulation tool using a three-dimensional model of OCL and a pantograph, which can calculate their full three-dimensional dynamic behavior. Each node in the OCL model has 6 degrees of freedom; this tool can evaluate contact quality between the OCL and a pantograph system even on curved sections. Furthermore, it can evaluate the expansion/contraction of OCL due to temperature change, which affects contact quality. This paper describes this simulation tool in detail, through the example of an analysis of the contact between contact lines and a pantograph from the results of a simulation of a pantograph passing a crossing section.

It is often difficult to determine the intervals at which trackside electronic equipment for railway signalling system needs to be replaced. In a previous study, Fujita et al. proposed a lifetime evaluation method for electronic interlocking equipment installed in an indoor environment. In this paper, the authors focus on the electronic equipment used in wayside signalling systems, which is exposed to more severe outside conditions. We evaluated the lifetimes not only of electronic components but also of substrates. The results of a case study using the developed evaluation method are also reported. Lifetimes depend on operating environment stress factors, especially temperature changes. Therefore, we recommend that replacement intervals should be adjusted according to the operating environment.

When a something occurs that could hinder a train passing a level crossing, obstruction warning signals are turned on to show that trains must stop. At present, this system relies on the driver's visual observation. This research aims to make this system more reliable and secure. This paper proposes a method to detect blinking obstruction warning signals and describes evaluation tests that were performed. Evaluation test results showed that these blinking signals could be detected with a detection rate of about 90 percent at a distance 600 meters under running conditions.

Since many Railway facilities are visually inspected, the use of camera images is being encouraged to improve inspection efficiency. A hyperspectral camera can acquire two-dimensional spatial information of a photographed object and spectral information spectroscopically divided into several dozens or more wavelengths. Using this camera, we expect to be able to capture changes in materials that are difficult to detect visually, from changes in wavelength distribution and intensity of specific wavelengths. This paper describes a basic test applying the proposed method using a hyperspectral camera for detecting rail deterioration, and reports on the obtained results.

This paper describes a study to develop a method for simulating structure borne noise on reinforced concrete viaducts, consisting of structural vibration and acoustic analyses. Results of acoustic analyses and measurements found that there was a high possibility of certain frequency bands where structure-borne noise was the main factor generating noise along the railway. Analytical evaluation of the results revealed that reinforcement of the center slab could reduce structure-borne noise by 1.1 dB at the 12.5 m point and 1.8 dB at the 25 m point.

In order to efficiently determine the weak points of the running safety in railway sections during large-scale earthquakes or existing structures with low yield seismic intensity, this paper proposed a simple evaluation method for running safety of railway vehicle during large scale earthquakes based on numerical simulations which quantified the degree of influence of nonlinear behavior of structures on the wheel derailment limit. The method can evaluate the occurrence of derailment only from the structural response such as the acceleration of the structure top and the angular rotation at the structural boundary.

Whereas air suspension is widely used for railway vehicles as secondary suspension, its hysteretic behavior possibly exerts a non-negligible influence on a vehicle's running characteristics, including unwanted wheel load variations in curves. To enable accurate and quick prediction of vehicle curve negotiation performances considering hysteretic air suspension behavior, this study proposes a new quasi-static curve negotiation analysis procedure using a thermodynamic air suspension system model that expresses in detail nonlinear airflow characteristics. This approach allows the elimination of the limitations of existing full dynamic simulation models associated with high computational intensity and is suited for vehicle running simulations over long-distances.