N700A Shinkansen Train Thinks For Itself, Using Automatic Operations To Follow the Schedule Exactly

2012-10-16

Rail Update Japan

N700A Shinkansen Train Thinks For Itself, Using Automatic Operations To Follow the Schedule Exactly

Shinkansen trains are entering a new age, getting closer to operating on their own. On August 21, JR Central gathered the press at its Hamamatsu Workshop to unveil its new N700A train for the Tokaido Shinkansen line. (The workshop is located in Hamamatsu’s Naka-ku district.) The most exciting feature of the new train is its ability to “think for itself” while slowing down or speeding up. It will do this using an on-board “automatic drive” system to run exactly according to schedule.

The company currently operates about 120,000 runs a year on its Tokaido Shinkansen track between Tokyo and Osaka, and the average delay per train is a mere 36 seconds. This super-punctual record is a matter of pride, but the new trains will push average delays down from 36 seconds to as close to zero as possible. They will make their commercial debut in February 2013.

The automatic drive system is a first for the Shinkansen in its almost 50-year history. What makes it possible is the company’s own computer program, installed on the trains as a Fixed Speed Running Device.

The device will read information on track gradient, curves, tunnels, etc. from computer terminals installed trackside at intervals of several kilometers along the approximately 552 km of line between Shin-Osaka and Tokyo. Then it will automatically cause the train to accelerate, decelerate or maintain speed in each track section, to run at the maximum speed for that section.

At the present time, Shinkansen drivers maintain the prescribed speed by continually making small adjustments to the throttle (notch) position. On curves and descending slopes, the driver reduces the throttle to decelerate to the prescribed speed, and applies more power on ascending slopes to maintain speed.

The driver has to continually check the schedule and correlate it with the track gradient, etc., to maintain the prescribed speed. The problem is that the Tokaido Shinkansen track has many curves and slopes, making it difficult for the driver to fully grasp every aspect of the track and operate the throttle accordingly. And in any case, human operations alone are bound to result in non-optimal acceleration and deceleration.

The Fixed Speed Running Device uses data on the curves and gradients ahead to calculate how much power to send to the motor, and how much throttle reduction is required. In this way, the train maintains the speed determined to be the maximum for its present track section. Human operation involves only pushing a button at the driver’s seat. However the driver will still operate the throttle as before, for station stops and the like.

Actually, though, the Fixed Speed Running Device will only be used after a delay caused by some incident, such as a natural disaster, to bring the train back on schedule. If it were used all the time, speeds would be so optimum that the train would jump ahead of the schedule and arrive at stations too early.

JR Central’s rolling stock manager explains: “If a train falls behind, to get back on schedule it has to maintain speed in the most effective way possible. But this is difficult using a human driver. That’s why we thought of having an automatic device do its part.”

The 36-second average delay experienced by Tokaido Shinkansen trains is the figure arrived at after including delays caused by natural disasters and other disruptions. So the automatic drive system will certainly help bring the number down.

The new trains are undergoing test runs, and six will begin revenue services in February 2013. By fiscal 2013, new trains will replace some of the current Series N700 models, making a total of 13 in service.

During the same time, and subsequently, the device will be installed in some existing N700s, so that by fiscal 2015 about 70% of the N700 fleet will have it.

When more than half the fleet has it, JR Central will be able to reflect this in a new schedule, running more trains and speeding up operations further.

The new rolling stock is the N700’s first modification in five years. By the way, the “A” of N700A stands for “Advanced.”

The exterior appearance of the N700A is the same as that of the N700. However, in addition to the automatic drive system, there are a number of other major innovations that are not visually apparent, such as a new type of brake capable of achieving a 10% reduction in stopping distance during emergency braking.

(Written by Tomohiko Uchiyama)

This article is taken from the SankeiBiz column that appeared in Japanese in the Sankei Shimbun newspaper on August 25, 2012. We thank the publisher, Sankei Digital, for granting permission to present the article translated under the auspices of JORSA.


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