-
Tomoki WADA, Katsuyuki MURAKI
2010 Volume 3 Issue 1 Pages
27-34
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
We have developed an on-car platform detection system using ultrasonic sensors. If a crew member tries to open the train doors when all or part of the train is not at a platform, this system could prevent passengers from falling from the train. But irregular reflection of the ultrasonic waves, due to the roughness of the slab of platform, caused unstable detection. Therefore, we have improved the system.
View full abstract
-
Yu HIBINO, Takayuki SHIMOMURA, Katsuya TANIFUJI
2010 Volume 3 Issue 1 Pages
35-43
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
In order to verify the validity of “a Detailed Equation,” a full scale experiment was conducted. The Detailed Equation is an equation of the equilibrium of the forces that act on a railway vehicle, which is similar to an equation for solving the overturning problem of a rigid body, but the external forces and the displacement of the car body are taken into account in detail. In the full scale experiment, a lateral force (representing the crosswind) was applied to the test vehicle, and the behavior of the vehicle was examined. As a result, it has been verified that the Detailed Equation is valid for evaluating the critical wind speed of overturning or the wheel unloading ratio.
View full abstract
-
Kazuhisa ABE, Shingo FUJISHITA, Kazuhiro KORO
2010 Volume 3 Issue 1 Pages
44-52
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
This paper presents a numerical method to construct transmitting boundaries for periodically supported railway tracks. This is realized by the derivation of impedance matrix for a half-infinite track. To achieve this, dynamic response of the infinite track corresponding to the half-infinite model is analyzed for a series of harmonic loading modes. The infinite problems are solved by virtue of Floquet transform. The developed method is applied to a periodically supported rail having a finite irregular zone subjected to harmonic loads. It is reduced to a dynamic problem of a finite track with the transmitting boundaries attached on both ends. Through comparison with the present method and a conventional way using a very long but finite railway model, the superiority over the truncated model is demonstrated.
View full abstract
-
Kiwamu TSUNO, Masaru FURUTA, Kazuhisa ABE
2010 Volume 3 Issue 1 Pages
53-62
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
This paper describes the development of prediction method for ground-borne vibration from railway tunnels. Field measurement was carried out both in a subway shield tunnel, in the ground and on the ground surface. The generated vibration in the tunnel was calculated by means of the train/track/tunnel interaction model and was compared with the measurement results. On the other hand, wave propagation in the ground was calculated utilizing the empirical model, which was proposed based on the relationship between frequency and material damping coefficient
α in order to predict the attenuation in the ground in consideration of frequency characteristics. Numerical calculation using 2-dimensinal FE analysis was also carried out in this research. The comparison between calculated and measured results shows that the prediction method including the model for train/track/tunnel interaction and that for wave propagation is applicable to the prediction of train-induced vibration propagated from railway tunnel.
View full abstract
-
Takeshi KURITA, Masaaki HARA, Haruo YAMADA, Yuusuke WAKABAYASHI, Fumio ...
2010 Volume 3 Issue 1 Pages
63-74
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
In order to reduce the pantograph noise that greatly contributes to overall noise, we have developed two types of low-noise pantograph. Further noise reduction was realized by the effects of attenuation of the pantograph noise insulation plate and by using only one pantograph per trainset. A multi-segment slider was also developed to increase the performance of following the overhead contact wire, which is imperative when running with only one pantograph per trainset. These countermeasures for pantograph noise have been installed on FASTECH 360 (high-speed test trains of East Japan Railway Company). The results measured by use of a microphone array show that the pantograph peak noise level is reduced by more than 2 dB compared to that of the series E2 trains now in operation.
View full abstract
-
Masakazu ADACHI, Yasuhiro SATO, Hiroyuki OHNO, Akira MATSUMOTO, Atsush ...
2010 Volume 3 Issue 1 Pages
75-82
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
Gauge widening has been set in order that rolling stock runs safely and smoothly on curved tracks. Recently gauge widening has been reduced due to the change of vehicle structures and track maintenance. The reduction of gauge widening may lead the decrease of steering ability of wheelsets and running safety of vehicles. The purpose of this study is to grasp curving performance and running safety when gauge widening was varied. Stand tests were carried out by a bogie test stand, and the authors concluded that the curving performance can be increased according to gauge widening, but the effect is limited in perfect rolling region, and not so effective for normal setting range.
View full abstract
-
Tsutomu WATANABE, Masamichi SOGABE, Kiyoshi ASANUMA, Hajime WAKUI
2010 Volume 3 Issue 1 Pages
83-91
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
A number of steel railway bridges have been constructed in Japan. Thin steel members used for the bridges easily tend to vibrate and generate structure-borne noise. Accordingly, the number of constructions of steel railway bridges tends to decrease in the urban areas from a viewpoint of environmental preservation. Then, as a countermeasure against structure-borne noise generated from steel railway bridges, we have developed a new type of the steel railway bridge equipped with a floating-ladder track and a floating reinforced-concrete (RC) deck. As a result of train-running experiment, it became apparent that the new steel railway bridge installed by double floating system has reduced a vibration velocity level by 10.5 dB(A) at main girder web as compared with a steel railway bridge installed by directly fastened track. This reduction effect was achieved by the ladder track and RC deck supported by resilient materials.
View full abstract
-
Masahiro SUZUKI, Koji NAKADE
2010 Volume 3 Issue 1 Pages
92-99
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
A basic study of flow controls using air blowing was conducted to reduce unsteady aerodynamic force acting on trains running in tunnels. An air blowing device is installed around a model car in a wind tunnel. Steady and periodic blowings are examined utilizing electromagnetic valves. Pressure fluctuations are measured and the aerodynamic force acting on the car is estimated. The results are as follows: a) The air blowing allows reducing the unsteady aerodynamic force. b) It is effective to blow air horizontally at the lower side of the car facing the tunnel wall. c) The reduction rate of the unsteady aerodynamic force relates to the rate of momentum of the blowing to that of the uniform flow. d) The periodic blowing with the same frequency as the unsteady aerodynamic force reduces the aerodynamic force in a manner similar to the steady blowing.
View full abstract
-
Gordana VASIC, Francis J. FRANKLIN, David I. FLETCHER, Ajay KAPOOR
2010 Volume 3 Issue 1 Pages
100-109
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
This paper describes a method to predict wear rates and time until fatigue crack initiation. A computer simulation of ratcheting wear is used to model the accumulation of plastic shear deformation in the rail and predict the wear rate, based on wheel-rail contact conditions. Contact data for two types of high speed trains at two sites on the East Coast Mainline, U.K., have been obtained from multi-body simulations of train-track interaction. Material microstructure has been modeled as grains of pearlite and ferrite in order to represent the real rail steel. Results showed that the wear rate increases as the proportion of Class-91/Mark-4 vehicles increases. Conditions for crack initiation arise at Harringay within 10,000 wheel passes. At Sandy, conditions for crack initiation do not arise until after 100,000 wheel passes, and arise soonest when traffic consists of only Class-91/Mark-4 vehicles. Together with fracture mechanics models for larger cracks, these models provide guidelines for rail grinding in order to optimize rail life and safety.
View full abstract
-
Yutaka SAKUMA, Masahiro SUZUKI, Atsushi IDO, Hiroshi KAJIYAMA
2010 Volume 3 Issue 1 Pages
110-118
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
Air velocity and pressure distributions on the sides of 16-car high-speed trains both in open and tunnel sections are measured to investigate the flow structure around the trains, especially in tunnels. For on-board measurement, hot-film probes, pitot tube rakes and pressure gauges are fixed on both sides of the 3rd car from the head end of the outbound train (and the 14th of the inbound). Two glass windows of the 3rd car are replaced with iron plates equipped with the apparatus. For on-the-ground measurement, ultrasonic anemometers and a pressure gauge are installed inside a tunnel at a point 800 m from a tunnel portal. The cruising speeds of the trains are set at between 250 and 290 km/h. It was found that the air velocity in the narrower space between the train side and the tunnel wall in the train coordinate system gradually decreases from the head toward the tail of the train while that in the other wider space increases, and that the features of the velocity and pressure fields observed on board in tunnel sections can be also detected on the ground.
View full abstract
-
Hynek MOCEK, Aleš FILIP, Lubor BAZANT
2010 Volume 3 Issue 1 Pages
119-130
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
Global Navigation Satellite System (GNSS) Galileo is expected to play an essential role in railway transport with view to reduce operational, investment and maintenance costs. However, quality requirements of the GNSS originate mainly from the aviation suggestions. Different safety philosophies used in aviation domain and in railway signaling complicate direct employment of the GNSS quality measures to the railway telematic applications. The objective of this paper is to outline the conception of railway requirements specification for the GNSS in order to cover a large amount of the appropriate applications in the non-safety and safety related domains. The elaborated methodology enables to provide specification of minimal quantitative requirements for GNSS system by means of railway attributes RAMS. This process generally represents contribution for GNSS system certification, when it is necessary to demonstrate that the GNSS system meets requirements, and the system outputs are correct. In the second level, certification of the specific GNSS application must follow subsequently.
View full abstract
-
Takahiro TOMIOKA, Tadao TAKIGAMI, Atsushi FUKUYAMA, Takashi SUZUKI
2010 Volume 3 Issue 1 Pages
131-142
Published: 2010
Released on J-STAGE: January 29, 2010
JOURNAL
FREE ACCESS
This paper discusses the issue of carbody excitation of railway vehicles due to rotation of imbalanced wheelsets and proposes a simple and cost-effective countermeasure. The basic mechanisms of the carbody excitation are first described, then a displacement-dependent rubber bush, which is used for the connection between bogie frame and carbody, is proposed. The displacement-dependent property is realized by introducing a small gap between the rubber and the inner fixture, and the transmission of excitation force with high-frequency and small displacement are isolated by the gap. The small gap can be created naturally just by skipping the bonding process of rubber and inner fixture, so it is very simple and cost-effective countermeasure against this issue. The stiffness property can be tailored to meet the requirements from motional properties of the bogie by applying a Finite Element Analysis (FEA). The effectiveness and validity of the displacement-dependent rubber bushes applied for traction links are investigated and confirmed by both numerical calculation and excitation test using a full-scale test vehicle in the rolling stock testing plant.
View full abstract
-
Stefano ALFI, Stefano BRUNI, Egidio DI GIALLEONARDO, Alan FACCHINETTI
2010 Volume 3 Issue 1 Pages
143-153
Published: 2010
Released on J-STAGE: February 02, 2010
JOURNAL
FREE ACCESS
The aim of this paper is to explore the possible benefits brought by the use of active control of the airspring secondary suspension for high speed railway vehicles; in this regard, active control is applied to reduce the vertical and pitch carbody oscillations in the low frequency range, according to the concept of skyhook damping. A concept is developed for the active airspring suspension, and a numerical model is derived for the vehicle equipped with the active suspension. The results obtained show that the use of active suspension control offers an important improvement of ride quality, by far larger than that achievable with semi-active suspensions. On the other hand, the issue of air consumption is outlined as a critical point of the proposed concept, requiring further research.
View full abstract
-
Hirotaka MORI, Hitoshi TSUNASHIMA, Takashi KOJIMA, Akira MATSUMOTO, Ta ...
2010 Volume 3 Issue 1 Pages
154-165
Published: 2010
Released on J-STAGE: February 02, 2010
JOURNAL
FREE ACCESS
This paper summarizes the development of a portable track-condition-monitoring system for easy installation on in-service vehicles. In this system, rail irregularities are estimated from the vertical and lateral acceleration of the car body. The roll angle of the car body, calculated using a rate gyroscope, is used to distinguish line irregularities from level irregularities. Rail corrugation is detected from cabin noise with spectral peak calculation. A GPS system and a map-matching algorithm are used to pinpoint the location of faults on tracks. Field test using in-service vehicle was carried out to evaluate the developed system. The results show that the condition of rail irregularity and rail corrugation can be estimated effectively.
View full abstract
-
Mohd Azman ABDULLAH, Yohei MICHITSUJI, Masao NAGAI, Naoki MIYAJIMA
2010 Volume 3 Issue 1 Pages
166-177
Published: 2010
Released on J-STAGE: February 12, 2010
JOURNAL
FREE ACCESS
Railway transport has been developed for a variety of requirements with a diversity of studies and technologies in recent years. In particular, the intercity railway transport that can be operated at speed of more than 350 km/h is the goal for the railway industry. Due to vibration and drag forces at high speed, contact force variation occurs between pantograph and catenary. This variation also causes instability in the pantograph and catenary interaction. In this study, multibody dynamics analysis is used to model the catenary. The integration of the catenary model and the pantograph model in the simulation flow produces contact force variations. A sinusoidal feed forward force and a simple feedback control force are applied to control the wave-like contact force fluctuations by means of active dampers. Evaluation of the combination of active control forces will produce optimized forces that may be able to maintain, thus improve the contact force variations.
View full abstract
-
Masafumi OGATA, Ken NAGASHIMA, Yoshiki MIYAZAKI, Masaru IWAMATSU
2010 Volume 3 Issue 1 Pages
178-186
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
The superconducting magnets (SCM) of electromagnetic vibration apparatus for MAGLEV ground coils operate in a persistent current mode for long periods of time. In addition, almost all of the time, the current lead of the SCM acts as a route for heat leak to the inside; therefore, the authors have developed low-heat-load current lead equipment. This equipment consists of a high-temperature superconductor (HTS) lead and the low-duty metallic lead allows the SCM to magnetize and demagnetize without a gas cooling system. This realizes a simplification of work procedure and reliable operations for magnetizing and demagnetizing the SCM. This result is also valuable for further improving the SCM of the MAGLEV vehicle.
View full abstract
-
Koichiro WAKI, Hiroshi SEINO, Ken NAGASHIMA
2010 Volume 3 Issue 1 Pages
187-195
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
The resonance modes of the on-board superconducting magnet for the JR Maglev system actually obtained at the durability test were two (propulsion and levitation modes). To reduce the durability test period of the specimen by half, it was investigated in this study how those two resonance modes were simultaneously reproduced. It appears that those two resonance modes are simultaneously reproducible if the three accelerating points to reproduce its levitation mode are used, and if proper beams to shift the resonance frequencies of its propulsion and levitation modes are added.
View full abstract
-
Erimitsu SUZUKI, Ken WATANABE, Hironori HOSHINO, Takenori YONEZU, Masa ...
2010 Volume 3 Issue 1 Pages
196-205
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
An experiment apparatus using a 1/12 scale model of a train car body was constructed to study the characteristics of vehicle dynamics of magnetically levitated high speed surface transport (Maglev) systems that differ from conventional railway systems. Consisting of six-axis parallel link motion bases to reproduce bogie motions, an aluminum car body, and secondary suspension units, this apparatus is expected to be useful in examinations of control methods to reduce vehicle vibrations and to generate data useful in eventually improving the precision of computer simulations. This report provides an overview of the Maglev vehicle model experiment apparatus and results of initial tests examining its fundamental characteristics.
View full abstract
-
Anneli ORVNÄS, Sebastian STICHEL, Rickard PERSSON
2010 Volume 3 Issue 1 Pages
206-215
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
A combination of increased vehicle speeds and non-improved railway tracks may have a negative impact on passenger comfort. Active technology can replace the conventional passive solution of the secondary suspension of a rail vehicle in order to maintain good passenger comfort even when vehicle speed is increased and track conditions are inferior. This paper focuses on the benefits of using a so-called Hold-Off-Device (HOD) function in the lateral secondary suspension. On-track tests have been performed with the active secondary suspension concept implemented in a two-car Regina train during the summers of 2007 and 2008. The evaluated measurement results have been very satisfactory and the device will be implemented in long-term tests in service operation. These tests were carried out in the beginning of 2009.
View full abstract
-
Paul HYDE, David FLETCHER
2010 Volume 3 Issue 1 Pages
216-225
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
Rail grinding is a widely used rail industry technique for maintaining the quality and safety of railway track. Rail grinding can be used to restore the profile of the rails, remove surface plastic damage and remove or reduce in size very early stage surface breaking rolling contact fatigue cracks. This paper focuses on the use of rail grinding to extend the safe life of a rail that would otherwise be limited by rolling contact fatigue (RCF) defects. The optimum grinding strategy for a variety of conditions has been investigated using a model that predicts the growth of surface breaking cracks in rails loaded by rail vehicle wheel contacts, taking into account natural wear of the rail and rail grinding. It was found that a grinding strategy which removes incipient cracks in a specific period of time without being over-conservative and producing excessive material loss must take into account all traffic using the line, not just the traffic perceived to be most damaging. A mixed traffic case is modelled, revealing the potential for interaction between different vehicle types in determining maintenance requirements.
View full abstract
-
Massimiliano PAU, Bruno LEBAN, Mario GUAGLIANO
2010 Volume 3 Issue 1 Pages
226-235
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
The ability to predict the criticality of internal cracks in railway wheels requires accurate knowledge of stress intensity factors K
I, K
II, K
III under contact loads. These factors depend both on the total load acting on the wheel and on how the load is transmitted through the wheel/rail interface, that is to say, they depends on the pressure distribution between wheel and rail. However, till today the solutions commonly used consider a theoretical (Hertzian) pressure distribution, even though the real contact patch may be far different for most of the lifespan of the wheel due to wear or to the dynamic conditions. In this paper an approach is developed with the aim of solving the case of an internally cracked wheel subjected to an arbitrary contact patch and pressure distribution. In particular, attention is focused on the case of hollow wear, which makes it possible to obtain very conformal contacts. The results are discussed and compared with the analytical solutions that consider Hertzian pressure distributions with the same total load.
View full abstract
-
Akiko MURAKOSHI, Taketoshi KUNIMATSU, Ayano SAITO
2010 Volume 3 Issue 1 Pages
236-242
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
This paper aims to reveal the fundamental features of customer satisfaction with train schedules, which is one of the most basic services provided by a railway company. A customer satisfaction survey of passengers who frequently utilize three lines in the metropolitan area was conducted; we obtained the following findings: (a) out of nine factors to evaluate a train schedule from a passenger's viewpoint, the four most important ones are the frequency of trains running, punctuality, congestion rate, and time distance; (b) the ride-frequency influences the degree of satisfaction with train schedules in a particular line; and (c) it is important to set a numeric goal for the level of customer satisfaction by grasping the relationship between the transport service and a passenger's satisfaction with that service. The difference between customer satisfaction and passenger disutility is also discussed. The findings are expected to help conduct customer satisfaction surveys and also to form the basis for establishing a method by which to evaluate a train schedule from passengers' satisfaction ratings.
View full abstract
-
Hirotaka MORI, Hitoshi TSUNASHIMA
2010 Volume 3 Issue 1 Pages
243-258
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
This paper demonstrates the possibility to detect suspension failures of railway vehicles using a multiple-model approach from on-board measurement data. The railway vehicle model used in this study includes lateral and yaw motions of wheelsets and bogie, and the lateral motion of the vehicle body. These motions are measured by on-board sensors for lateral acceleration and yaw rate. The detection algorithm is formulated based on the interacting multiple-model (IMM) algorithm adding a method updating estimation model. The IMM method has been applied for detecting faults in vehicle suspension systems in a simulation study. The mode probabilities and states of vehicle suspension systems are estimated based on a Kalman filter (KF). This algorithm is evaluated in simulation examples. Simulation results indicate that the algorithm effectively detects on-board faults of railway vehicle suspension systems in realistic situation.
View full abstract
-
Takahiro SAITOH, Sohichi HIROSE
2010 Volume 3 Issue 1 Pages
259-270
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
This paper presents the influence of a pile on ground vibration induced by a moving train in an underground tunnel. A coupling of 2.5-D and 3-D boundary element method (BEM) is used to obtain displacement amplitudes on a surface around the pile top. First, a 2.5-D BEM is used to obtain an incident wave field in a 3-D half space, without a pile, subjected to an underground moving load. Second, 3-D BEM is carried out for a soil-pile model using the obtained incident wave field. Numerical results show that the presence of a pile may increase the ground vibration level around the pile top at low frequencies.
View full abstract
-
Tomoko HORISHITA
2010 Volume 3 Issue 1 Pages
271-276
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
In this paper, I describe the Safety Research Institute and give details concerning the institute's human factors textbook and the educational program that has been developed using this textbook. The human factors textbook was created in order to shed light on human factors and mechanisms leading to human error. Thirty-two items were selected from general knowledge about human factors and these items were discussed using familiar examples and clear, non-technical explanations. An educational program, consisting of a series of lectures based on the principles covered in the textbook, has been created in order to further the understanding of human factors. The contents of the educational program have been arranged based on the needs of the students. Furthermore, we conducted a survey in which students were given a questionnaire in order to examine the educational effects of the textbook and lectures, and we are using these results to refine our programs. According to the results of the questionnaire, the lectures have received high ratings in terms of understandability and satisfaction. The results regarding the level of difficulty indicate the material covered in the lectures was at a level appropriate for the students.
View full abstract
-
Tatsuya IIZUKA, Katsuya TANIFUJI, Hitoshi SOMA
2010 Volume 3 Issue 1 Pages
277-286
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
This paper deals with the potential of an active-steering bogie to reduce the large lateral axle load that arises at worn welded joints of the outer rail in a curved track when high-speed trains pass. The shape of the worn joint, called lateral ‘angular bent’, is modeled on the basis of the measured irregularity shape of actual joints. Then, numerical simulation of running on a curved track is carried out for a two-axle bogie vehicle to compare an active-steering bogie and a conventional nonsteering bogie. The behavior of the vehicle negotiating the curve is evaluated from the viewpoints of decreasing the peak value of lateral axle load within the allowance limit and maintaining the running stability. To satisfy the requirements, wheelset-supporting parameters and feedback gains for active-steering are optimized on a curved section of 400 m radius by the Genetic Algorithm. On the basis of the optimized wheelset-supporting parameter values, additional sets of feedback gains, which are adjusted for the curves of different radii, are proposed. The numerical simulation shows that the operation speed of a vehicle with active-steering bogies having the optimized parameter values has the potential to be raised to the possible speed for tilting trains while satisfying the criterion of riding comfort.
View full abstract
-
Chizuru NAKAGAWA, Ryohei SHIMAMUNE, Ken WATANABE, Erimitsu SUZUKI
2010 Volume 3 Issue 1 Pages
287-293
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
To develop a more suitable method of evaluating ride comfort of high speed trains, a fundamental study was conducted on sensitivity of passengers to various frequencies of vibration with respect to ride comfort. Experiments were performed on 55 subjects using an electrodynamic vibration system that can generate vibrations in the frequency range of 1 to 80 Hz in the vertical direction. Results of experiments indicated that the subjects tend to experience greater discomfort when exposed to high frequency vibrations than that presumed by the conventional Japanese ride comfort assessment method, the "Ride Comfort Level."
View full abstract
-
Atsushi IDO, Shuya YOSHIOKA
2010 Volume 3 Issue 1 Pages
294-304
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
We developed a model running facility to study the flow of the under-floor of railway car. The facility was set up in the test section of the Towing Wind Tunnel Facility where by a hood we can eliminate disturbances, such as natural wind. We carried out the model running tests and measured the velocity distribution under the model car. The velocity distribution was almost the same as in the rear cars from the car No.3, and the velocity between the rails was less than the velocity outside of the rail.
View full abstract
-
Toshiyuki SHIMAZOE, Hideto ISHIKAWA, Tsuyoshi TAKEI, Kenji TANAKA
2010 Volume 3 Issue 1 Pages
305-314
Published: 2010
Released on J-STAGE: February 23, 2010
JOURNAL
FREE ACCESS
Recent types of train protection systems such as ATC require the large amounts of low-level configuration data compared to conventional types of them. Hence management of the configuration data is becoming more important than before. Because of this, the authors developed an error-proof system focusing on human operations in the configuration data management. This error-proof system has already been introduced to the Tokaido Shinkansen ATC data management system. However, as effectiveness of the system has not been presented objectively, its full perspective is not clear. To clarify the effectiveness, this paper analyses error-proofing cases introduced to the system, using the concept of QFD and the error-proofing principles. From this analysis, the following methods of evaluation for error-proof systems are proposed: metrics to review the rationality of required qualities are provided by arranging the required qualities according to hazard levels and work phases; metrics to evaluate error-proof systems are provided to improve their reliability effectively by mapping the error-proofing principles onto the error-proofing cases which are applied according to the required qualities and the corresponding hazard levels. In addition, these objectively-analysed error-proofing cases are available to be used as error-proofing-cases database or guidelines for safer HMI design especially for data management.
View full abstract
-
Yasukuni NAGANUMA, Mikihito KOBAYASHI, Takayuki OKUMURA
2010 Volume 3 Issue 1 Pages
315-325
Published: 2010
Released on J-STAGE: March 03, 2010
JOURNAL
FREE ACCESS
We have developed three inertial measurement processing techniques to measure the longitudinal level of tracks using the devices mounted on the commercial shinkansen trains. Two of them, labeled as the ”Frequency variable difference filter” and the ”Speed variable moving summation”, employ digital processing, while the other employs analogue processing applying a frequency variable low-pass filter. Through a series of the simulation tests, the above all methods were found to be capable of deriving a 10 m versine longitudinal level directly from the measured acceleration with high precision without causing any waveform distortion. An experimental prototype of a digital inertial device applying the ”Frequency variable difference filter” that can help to minimize the processing load was produced, and its reliability was investigated. As a result, the output by means of the proposed prototype revealed good correlation with the data collected from an existing track geometry car. After the successful test results were obtained, the devices have so far been manufactured and installed in six N700 commercial trains. The repeatability was also found to be excellent, thus the device is expected to detect even a slight change of the track.
View full abstract
-
Qinghua GUAN, Jing ZENG
2010 Volume 3 Issue 1 Pages
326-337
Published: 2010
Released on J-STAGE: March 25, 2010
JOURNAL
FREE ACCESS
It is known to all that derailment is the vital problem in railway transportation. As the increase of vehicle speed, the possibility of derailment due to the lateral impact between the wheel flange and the rail increases. An impact model for the impact between the wheel and rail together with an accurate kinematic analysis is presented in order to shed some light on the wheel lift derailment of high-speed vehicles.
View full abstract
-
Yoshitaka MARUMO, Hitoshi TSUNASHIMA, Takashi KOJIMA, Yasushi HASEGAWA
2010 Volume 3 Issue 1 Pages
338-348
Published: 2010
Released on J-STAGE: March 29, 2010
JOURNAL
FREE ACCESS
The safety devices for train systems are activated in emergency situations when a risk becomes obvious, and the emergency brake is applied. If such systems are faulty, the drivers' operating errors may cause immediate accidents. So it is necessary to evaluate potential risks by detecting improper driving behavior before overt risks appear. This study analyzes the driving behavior of train drivers using a train-driving simulator. We focus on braking behavior when approaching a station. Two methods for detecting unusual braking operation are examined by giving drivers mental calculation problems as a mental workload. The first is a method monitoring the driver's brake handle operation, and the second is a method measuring vehicle deceleration. These methods make it possible to detect unusual driving.
View full abstract
-
-Efficiency Calculation Assuming Perfect Regenerative Braking-
Takafumi KOSEKI, Takashi NODA
2010 Volume 3 Issue 1 Pages
349-357
Published: 2010
Released on J-STAGE: April 06, 2010
JOURNAL
FREE ACCESS
Mechanical brakes are often used by electric trains. These brakes have a few problems like response speed, coefficient of friction, maintenance cost and so on. As a result, methods for actively using regenerative brakes are required. In this paper, we propose the useful pure electric braking, which would involve ordinary brakes by only regenerative brakes without any mechanical brakes at high speed. Benefits of our proposal include a DC-electrification system with regenerative substations that can return powers to the commercial power system and a train that can use the full regenerative braking force. We furthermore evaluate the effects on running time and energies saved by regenerative substations in the proposed method.
View full abstract
-
Hiroshi MOCHIZUKI, Sei TAKAHASHI, Hideo NAKAMURA, Satoshi NISHIDA, Min ...
2010 Volume 3 Issue 1 Pages
358-371
Published: 2010
Released on J-STAGE: April 06, 2010
JOURNAL
FREE ACCESS
To realize high-speed data transmission for railway signaling systems, we propose a novel modulation method combining code-division multiple access (CDMA) and quadrature amplitude modulation (QAM), called the CDMA-QAM method. We evaluated the effectiveness of the proposed method and developed a CDMA-QAM rail transmission system based on DSPs and an FPGA. In addition, we conducted a field trial using an actual rail.
View full abstract
-
Pingbo WU, Ren LUO, Yan HU, Jing ZENG
2010 Volume 3 Issue 1 Pages
372-379
Published: 2010
Released on J-STAGE: April 13, 2010
JOURNAL
FREE ACCESS
The light rail vehicle with Linear Induction Motor (LIM) bogie, which is a new type of urban rail traffic tool, has the advantages of low costs, wide applicability, low noise, simple maintenance and better dynamic behavior. This kind of vehicle, supported and guided by the wheel and rail, is not driven by the wheel/rail adhesion force, but driven by the electromagnetic force between LIM and reaction plate. In this paper, three different types of suspensions and their characteristic are discussed with considering the interactions both between wheel and rail and between LIM and reaction plate. A nonlinear mathematical model of the vehicle with LIM bogie is set up by using the software SIMPACK, and the electromechanical model is also set up on Simulink roof. Then the running behavior of the LIM vehicle is simulated, and the influence of suspension on the vehicle dynamic performance is investigated.
View full abstract