Railroad Rolling Stock Control Technology for the Next Generation

Railway Technical Research Institute
Vehicle Technology Development Division

 It has been said that the technologies used in railroad are based on experimental engineering and they are, by now, quite mature technologies. However, most of the latest technologies supporting today's railroads are new technologies developed in the late twentieth century or in past 20 years. These technologies include: light-weight cars using aluminum and stainless steel; highly stable high-performance lightweight railway trucks that enable high-speed operation at 200 - 300 km/h; environmentally friendly technologies; car vibration control technology to make trains more comfortable to ride; electromagnetic induction motor drive control technology using VVVF inverters; and the car-tilt controlling technology that enables trains to run on curved tracks without sacrificing either passengers' comfort or speed. With competition from automobiles and airplanes intensifying, for the railroad to remain an important means of transport, it is imperative to upgrade our technology standard toward the next generation by developing new technologies that meet the requirements of passengers and railroad operating companies in a timely fashion.

  To this end, the Railway Technical Research Institute's Vehicle Technology Development Division is undertaking research and development to achieve:
- Reliable railroads with high-levels of safety and stability of operation
- Low costs with energy and labor saving
- Railroads that make passengers happier through shorter commuting times, better convenience realized by joining different lines and more comfortable rides.
- Environmentally friendly railroads with low noise and less vibration.

  Among these research subjects, those concerning "the control of rolling stock" have always been important ones. I believe that research on these subjects is very important in order to achieve intelligent rolling stock by realizing the above-mentioned targets: i.e. improved reliability of rolling stock, energy saving, labor saving, cost reduction, a higher degree of convenience and comfort for passengers, harmony with the environment, and so on. Actual examples of the controls we need include:
- the axle steering control which enables stable high-speed operations and high cornering performance at the same time
- higher-level, more effective vibration and tilt control with learning capability
- electric brake control which is capable of making use of all the braking power from the high-speed area till the moment of stopping
- equipment diagnosis and repair control that aims for the improved reliability and labor-efficient maintenance of carrier equipment
- driving control that detects obstacles in front and automatically stops the car to ensure safety
- moving and braking control that minimizes the spinning and sliding
- main circuit control that restricts the generation of harmful noise such as high-frequency currents

  In controlling the various instruments and functions of railroad rolling stock, the following points must be noted.
- Understand the characteristics of rolling stock and each of the devices to be controlled and use the control methods that match the characteristics.
- Make sure that the control is always fail-safe.
- Make thorough investigation to lower the initial, operating and maintenance costs of the implementation of control.

  In this edition, examples of the following controls are introduced.
- car vibration control to make trains more comfortable to ride
- car list control and axle steering control of swinging cars
- permanent magnet main electric motor control for electric engines
- high-frequency current control for electric engines
- spinning and re-gripping control for electric engines

  The Railway Technical Research Institute's Vehicle Technology Development Division will continue to work on its research and development to fulfil the expectations of customers and railroad companies such as JR, while always staying aware of the needs of society.