The Japan Society of Mechanical Engineers
International Symposium on Speed-up, Safety and Service Technology for Railway and Maglev Systems 2009 (STECH’09) 2009.6.16-19 Niigata JAPAN
THE BODY INCLINING SYSTEM OF THE SERIES N700 SHINKANSEN
Yasuki Nakakura *1 and Kosuke Hayakawa *2
*1 Shinkansen Operations Division, Central Japan Railway Company, [email protected] *2 Shinkansen Operations Division, Central Japan Railway Company, [email protected]
ABSTRACT 2. OVERVIEW OF THE BODY INCLINING The Series N700 is the first Shinkansen rolling stock to SYSTEM employ a body inclining system, which allows speed increases on curves while maintaining riding comfort. 2.1 Requirements of the body inclining system for a For use in the Tokaido Shinkansen, such a system needs Tokaido Shinkansen train-set to be light-weight and possess a reliable means to provide Over the years, body inclining system has been used with high precision position data. Reliability is a crucial factor conventional trains, but no such system has been when considering that the Tokaido Shinkansen operates a employed in Shinkansens excluding cases of test use. maximum of 13 train-sets per hour. In order to meet these Looking at high-speed trains in Europe, there exist cases requirements, the Series N700 adopts a simple and light where body-inclining mechanisms have been adopted weight air-spring based body inclining mechanism, such as the Italian ETR450 and the Swedish X2000. which combines the new automatic train control (ATC) However, their mechanisms are complex and heavy, technology capable of providing reliable high-precision making them unsuitable for use in the Tokaido position data, and control transmission technology that Shinkansen, where axle load restriction is strict. In simultaneously transmits position data digitally to all the addition, with trains operating at high speeds, accurate cars in a 16 car trainset. speed and position data are crucial. Furthermore, with a maximum of 13 train-sets operating per hour, a high level of reliability is a prerequisite to ensure reliable 1. INTRODUCTION transportation.
The Series N700 was jointly developed by JR Central and JR West under the concept "latest, fastest and the best rolling stock for direct operations on the Tokaido and Sanyo Shinkansen". It commenced commercial operation in July, 2007 and has been operating in a good state.
The body inclining system adopted in the Series N700 was developed to shorten travel time without sacrificing ride comfort. The quest to develop a body inclining system for a Shinkansen train-set began in 1999, with the 300X experimental train. The system has been refined Fig.1 The Series N700 Shinkansen through tests on one of the Series 300 train-sets and the prototype of the Series N700, taking into consideration In developing the body inclining system these the durability of the hardware. We also made use of the requirements had to be met. Vehicle Dynamic Simulator (a simulator that can simulate the vibration acceleration of rolling stocks) at 2.2 Necessity for body inclination in the Tokaido the JR Central Research Center in order to assess ride Shinkansen comfort with the body inclining system in action. There are curves of radius 2,500m on the Tokaido Shinkansen, which is relatively small for a line operating It is with the maturation of this system that made possible high-speed trains. Since the debut of the Series 300 in the speed increase at curves of radius 2,500m from 1992, the maximum operating speed was increased from 250km/h to 270km/h, the maximum speed on the 220km/h to the current 270km/h, but when traveling Tokaido section. This speed increase has made a big through curves of radius 2,500m, speed is reduced to contribution to shorten travel time between Tokyo and 250km/h to ensure ride comfort. Due to this speed Shin-Osaka by 5 minutes from 2 hours and 30 minutes to restriction, we are only able to operate at the maximum 2 hours and 25 minutes. speed of 270km/h on 1/3 of the whole line. By removing this restriction, 2/3 of the whole line can be operated at
Transportation and Logistics Division Japan Society of Mechanical Engineers (JSME)
NII-Electronic Library Service The Japan Society of Mechanical Engineers
International Symposium on Speed-up, Safety and Service Technology for Railway and Maglev Systems 2009 (STECH’09) 2009.6.16-19 Niigata JAPAN
the maximum speed of 270km/h, thus making it possible structure of the bogie. Since the bogie structure is to reduce travel time between Tokyo and Shin-Osaka by fundamentally identical to those in commercial operation, approximately 5 minutes. running stability is basically guaranteed.
Fig.4 Overview of the body inclining system
Fig.2 Running Curve 2.4 Position detection To achieve smooth inclining at high speeds, accurate Restriction of speed at curves, as already mentioned, is to position detection is necessary. With the Series N700 the ensure ride comfort. It is necessary to keep lateral new ATC technology is utilized to obtain accurate acceleration felt by passengers to less than 0.9m/s2. With position data together with accurate speed data. The train a train traveling through curves of radius 2,500m at a control and communication network is used to transmit speed of 270km/h, this demand can be met by inclining these data simultaneously to all 16 cars over a distance of the body by only 1 degree. Thus our body inclining 400m. system was developed to meet this target. The new ATC and train control and communication network technology have both been developed by JR Central independently of the body inclining system. We fused these technologies and the air-spring based inclining mechanism in such a way to achieve a light-weight, safe and reliable body inclining system.
3. COMPONENTS OF THE BODY INCLINING SYSTEM
3.1 System Formation Fig.3 Lateral Acceleration Since the Tokaido Shinkasen operates a maximum of 13 trains per hour, the body inclining system as a whole 2.3 Air-spring based inclining mechanism needs to be extremely reliable. The component systems When a train travels through curves, passengers feel the which are used to obtain and deliver the speed and lateral acceleration from the centrifugal force. position data to all 16 cars of the train-set, namely the Conventional trains have been taking advantage of new ATC and the train and communication network, are various forms of body inclining systems for decades, both dual control systems and for added reliability there none however, suitable for Shinkansen use due to its is redundancy of transmission routes. Further, to ensure complex and heavy mechanism. safety, a cyclic redundancy check (CRC) is performed to each transmitted data. In order to adopt a body inclining system in a Shinkansen train, the system needs to be simple and light weight. The Each car is equipped with one body inclining control system used in conventional trains requires the bogie to device, two electro-magnetic valve units that injects and possess tilt mechanisms such as tilting beams and withdraws air in and out of the air-springs, and height bearings, making it heavy. Such a system is unsuitable sensors equipped near each of the air-springs. The circuit for the Tokaido Shinkansen, since there is a stringent axle for sending commands from the control device to the load restriction. electro-magnetic valve units to switch on and off the valves, and the pneumatic circuit for inflating and Since the required body inclining angle is 1 degree, deflating the air-springs have been designed to be failure which is small in comparison with angles required in tolerant. The height sensors equipped near the air-springs conventional trains, we were able to select the air-spring to feedback the height of the car to the control device are based inclining mechanism, which is relatively light dual sensors making them tolerant to failures as well. weight and does not require a major modification in the Further, for added reliability and safety, there is a “limit
Transportation and Logistics Division Japan Society of Mechanical Engineers (JSME)
NII-Electronic Library Service The Japan Society of Mechanical Engineers
International Symposium on Speed-up, Safety and Service Technology for Railway and Maglev Systems 2009 (STECH’09) 2009.6.16-19 Niigata JAPAN
switch” equipped near each air-spring to detect an abnormal inclination to abort inclination of the whole 3.3 Electro-magnetic valve unit train-set. When this “limit switch” is activated, an There is one electro-magnetic valve unit per bogie, and it all-time active line drawn through all 16 cars of the is composed of electro-magnetic valves and an air tank in train-set is cut off, thereby allowing to abort body order to inject and withdraw air in and out of the inclination all together. This circuit is used to abort body air-springs. It is located near the bogie (the air-springs) as inclination for other failures that may lead to an abnormal much as possible to shorten and optimize the pneumatic inclination. circuit. For reliability, proven technology used in brakes has been utilized where possible.
There are altogether 6 electromagnetic valves for each air-spring, three for inflating and three for deflating, with each valve having different air flow capacity. These valves are switched on and off according to the command from the control device. On the input end of the 6 valves there is a cut-off valve. When the control device detects a malfunction in the system, the cut-off valve is shut to stop the air from being injected into the air-spring. In the output end of the 6 valves, there is a valve that switches the passage of air flow from the body inclining Fig.5 System diagram of the body inclining system pneumatic circuit, to the body leveling pneumatic circuit used in conventional Shinkansen rolling stocks. This 3.2 Body inclining control device valve switches the air flow to the conventional body Each car is equipped with one body inclining control leveling pneumatic circuit at the same time as the cut-off device. The body inclining control device sends valve is shut. commands to the electro-magnetic valve units to switch on and off the valves to inflate and deflate the air-springs. It is a dual-control device utilizing a highly reliable dual CPU with proven performance in the new ATC.
The device receives accurate speed and position data via the train and communication network. It then collates these data with the preinstalled map data, and calculates the necessary inclining angle and target body height. Then it determines the deviation of the actual height of the body from the target body height and selects the necessary output required from the electro-magnetic valve units.
The dual-control body inclining control device has two Fig.7 Electro-magnetic valve unit sets of software installed to carry out the above mentioned calculation in order to avoid malfunction from programming errors. In this way, it is possible to reduce the chances of the body inclination system from failing altogether due to a bug in programming.
Fig.8 Pneumatic circuit
3.4 Height sensors and “limit switch” There is a height sensor equipped with a “limit switch” for each air-spring. The height sensor is a non-contact Fig.6 The body inclining control device rotational type dual sensor, which is simple in structure
Transportation and Logistics Division Japan Society of Mechanical Engineers (JSME)
NII-Electronic Library Service The Japan Society of Mechanical Engineers
International Symposium on Speed-up, Safety and Service Technology for Railway and Maglev Systems 2009 (STECH’09) 2009.6.16-19 Niigata JAPAN
and capable of detecting coil severance with certainty. It inclining system. The body inclining system allows 2/3 detects the angle of the lever of the body leveling of the whole line to be operated at the maximum speed of mechanism which is converted into body height by the 270km/h, thus succeeding to reduce the frequency of control device. The “limit switch” detects an abnormal acceleration and deceleration, thereby substantially inclination and aborts inclination of the whole train-set. cutting down on energy consumption.
The body inclining system we developed is a failure tolerant and extremely reliable system for a high speed train-set that is as long as 400m long. Currently, we are steadily increasing the number of Series N700 train-set equipped with this body inclining system put into operation. Thus, the reliability of the system will be further put to the test, but we are confident that the system will stand to it as there has been no major problem with the system since the start of operation in July, 2007. In the coming future we will make Fig.9 Height sensor modifications where necessary by analyzing in detail data obtained from the monitoring system and data from 3.5 Monitoring of the body inclining system maintenance to perfect the system further. Body inclination of the train cars is monitored by a status monitoring system installed on all Series N700 train-sets. Data related to the status of operation of the REFERENCES body inclining system, such as train speed, air-spring target height, and actual air-spring height, are [1] Sakanoue, K.,Kanbayashi, K., Usui, S. and Furuya, automatically transmitted from the monitoring device M.: The developing of the first body inclining system installed on the rolling stock to on-ground servers via for the Shinkansen, JREA, Vol.46, No.10. SS radio. [2] Usui, S. and Furuya, M.: Overview of the Body Inclining System in the Series N700, JREA, Vol.48,
No.9 (2005). Data stored in the servers is analyzed by computers in [3] Kanbayashi, K., Sakanoue, K., Otsuka, T., Ueno, M., ground terminals thereby ensuring the soundness of Usui, S. and Furuya, M.: The Body Inclining System operation of the body inclining systems on all of the Series N700 Shinkansen Utilizing the New ATC train-sets. System, J-Rail (2007).
We can also output this data in chart form for confirmation purposes. With this status monitoring system, we can predict failures of the body inclining system before they happen and compare data between the various train-sets.
Fig.10 Monitoring of the body inclining system
4. SUMMARY
We have succeeded in shortening travel time between Tokyo and Shin-Osaka by 5 minutes with the body
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