This short paper briefly summarizes some key events in the history of the speed-up of railways. Some of the factors inhibiting speed-up of the railway as a system are reviewed : safety, passenger comfort, economics and environmental performance. Finally, some speculations are made on the future of railway speed-up.

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This paper deals with the addition of centering control to the active suspension of a tilting rail vehicle. The H_∞ control that aims cooperative control of the centering with the vibration suppression is examined by numerical simulation and verified in the experiment with 1/6 scaled half-vehicle model. The cooperative control is executed by same actuator, and the H_∞ controller is confirmed to be available also to tilting vehicles negotiating curved tracks at high-speeds.

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In this paper we introduce "active-bogie-steering (ABS) truck", that is one of the methods to realize the compatibility between curving performance and hunting stability. The ABS truck has active steering mechanism only between car body and truck frame, and truck flame is steered by actuators toward "radial steering position", which realizes no "bogie angle shortage". Validity tests were carried out on the truck rolling test stand in NTSEL, which can simulate curve-running condition. According to the test results, 1) "lateral contact force of front/outside wheel" in curving is proportional to "bogie angle shortage", 2) "bogie angle shortage" is proportionally reduced by bogie-steering actuator force. So the lateral force of the front/outside wheel in curving can be reduced by active-bogie-steering, and it is possible to realize zero lateral force even in sharp curve.

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Magnetically levitated vehicles, also called as MAGLEV vehicles, have been gaining attention as the next generation of high-speed public transportation that has advantages such as high speed and low emission. One of the problems in development of the MAGLEV vehicle has been its unsatisfactory ride comfort. In this research, a half vehicle cross-sectional model is used to explore the design and effects of a vibration control system applied to the secondary suspension between the car body and bogie. When vibration reduction is done only with lateral actuators between the car body and bogie, the roll vibration of the car body could increase in the low frequency range, although the lateral vibration is reduced. On the other hand, the use of both lateral and vertical actuators leads to higher costs though obviously is more effective. To solve these problems, this paper clarifies the vibration modes of the car body and bogie by modal analysis of the coupled vibration system. Based on that result, a configuration of reduction devices and actuators that takes the vibration mode into account is proposed, and its effect is confirmed by computer simulation.

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In recent years, there has been growing needs to improve maximum speed on curved tracks. For this purpose, there are many tilting systems. However, vehicles that have special tilting mechanism, are much different from the ordinary ones and expensive. Thus we have developed a tilt control system that is constituted from the ordinary car body and bogie truck with less remodeling. Therefore the maximum tilting angle of this system is restricted to 2 degrees. This system mainly consists of a Controller, Air supply valves, Exhaust valves and Height sensors. The control method is programmed. The tilting operation is performed by the controller, which all data of the curved tracks have been memorized. The location of the vehicle is measured by the tachometer generator and the devices (ground coil) that are attached on the sleeper in order to correct running position. From several running test results, we confirmed that stationary lateral acceleration of car body was reduced by tilt control. The running stability and riding comfort was also adequate so the vehicle equipped with this system could run rapidly than the vehicle with the former restricted speed limit on curved track.

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This paper aims to analyze fundamental dynamic characteristics of tilting railway vehicle using variable link mechanism for compensating both lateral acceleration that passengers feel and wheel load imbalance between inner and outer rails In this report, geometric relations between the center of rotation, the center of gravity, and the positions of all four links of tilting system are analyzed. Then, equations of the pendulum motions of railway vehicle body with four-link mechanism are derived. Then, "perfect tilting condition", which is the control target of feedforward tilting control, is derived by linear equation of tilting motion.

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This study aims to analyze fundamental dynamical characteristics of a tilting railway vehicle using variable link mechanism for compensating both lateral acceleration that passengers feel and wheel load imbalance between inner and outer rails. To realize the "Perfect tilting condition" on curved section, optimal control theory using LQI regulator is applied to the vehicle body tilting system with a newly developed variable link mechanism. From computer simulation and experiment it is clarified that the proposed system is effective to suppress both over-centrifugal acceleration and wheel load imbalance.

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On curved rail, the speed of train must be reduced in order to keep riding comfort. So, the train has the speed limitation in conventional railway line. But if the train has the tilting mechanism, the speed of train is able to be increased while maintaining the riding comfort. Generally, the tilting train is faster than the non-tilting train about 30% in curve. The tilting train technology and reduction of travel time has been carefully investigated by KRRI (Korea Railroad Research Institute). Based on the primary research result from KRRI, tilting control system and tilting operation interface are considered its core technology to apply tilting train to Korean conventional railway. Passenger comfort is controlled by amount of tilted car body. So the smoothness of interface between tilting bogie and car body during the tilting system operation is very important factors to estimate its capability.

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We describe the development of the diagnostic device using low frequency elastic wave and the results of the tests by this device to verify this diagnostic method for detecting existence and depth of interior defect of real tunnel lining concrete.

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In this study, the authors discuss the methods to assess the future/actual damage of RC structures by using the numerical simulation and the vibration measurement. First, the applicability of the AEM is examined as an assessment tool for the seismic performance of RC structures. with/without retrofit construction, by means of the simulation of cyclic loading test and seismic response of RC structures. Next, the method to improve the accuracy of vibration diagnoses of earthquake-damaged RC structure is discussed by using the damage judgment criteria calculated by AEM.

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Deflections of consecutive bridges excite vehicles at a constant period. The current design standard provides the deflection limit value of bridge from viewpoints of running safety and riding comfort for the speed up to 260km/h. In this study, influences of dominant parameters on dynamic responses of bridges and vehicles were examined by numerical analyses to expand the applicability of design standard in the high-speed range. In addition, dynamic responses of 17 bridges of various structure types with different span lengths were measured that consisted by vehicle running tests. The carbody accelerations of vehicles were also measured relating to bridge deflections and they were studied from viewpoints of length and rigidity of bridge. Peak-to-peak amplitudes of carbody accelerations were approximately 1.5m/s^2 or less on all bridges. A new provision for the railway design standard was proposed based on this study.

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It is very important to understand the mechanism of track deterioration and predict track settlement or track irregularity growth rate for reducing track maintenance cost and designing new components of track structures. Some prediction models of track settlement which mainly consists of a vehicle/track dynamic model and a track settlement law have been so far proposed. In this paper, a prediction model of track settlement based on dynamic simulation and Japanese ballast settlement law is described and its adequacy has been studied in comparison between analytical results and measured results obtained during almost five years at a track site. As a result, good agreement with the analytical results and the measured results has been obtained.

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The increased track work due to the cause of wheel flat is calculated using the analyzed results on the wheel drop test, on the deterioration of track and on the convergence of track irregularity. The first gives the equivalent rail roughness to the impact of wheel flat. The second selects an adequate track deterioration law. The third calculates the increase of track maintenance work.

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Recently, as the velocity of train has been improved and the operation of the express train has been increased, the ground-transmitted vibrations can be a serious problem. For example, the location of a precision machine shop near a railway, or of delicate laboratory apparatus in a plant area containing heavy drop forging machinery or unbalanced rotating machinery are typical situations in which ground-transmitted vibrations may pose serious problems. This paper investigated the reduction effects on ground vibration before and after installing the continuous welded rail on the basis of field tests.

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We are developing the energy evaluation simulator which performs a public transportation running on digital maps in a computer as a selecting tool for urban transportation construction planning. Using the simulator, it is easy to calculate various running characteristics such as total travel time or total consumption of electric power of public transit systems traveling along routes specified on street map. In this paper, features of the simulator and calculated results are discussed.

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This paper deals with a fault tolerant architecture of Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) based train position locator (TPL) intended for railway signalling and train control. Sensor and process fault detectability is outlined within the proposed architecture. Main attention is paid to sensor data validation by means of the Probability Data Association Filtering (PDAF) approach. Further, train routing detection on a switch using gyro-odometry and Bayes' theorem is proposed. The experimental verification of the presented procedures has been performed by means of 3kV DC electric locomotive on the experimental track.

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To communicate between a train and various destinations were very difficult resent days. But development of radio technologies and 'everything on IP' make it possible. We are aiming 'Unified IP Network' for train drivers, conductors, rail-side workers and passengers boarding the trains to provide data and voice communications, over wireless IP network. But broadband radio network was very expensive and spread spectrum modulation was very special past days. Development of Wireless LAN system makes it real. We are decided to put IEEE802.11b radio stations every 400-600m at wayside to communicate to the rolling stocks to experiment. To keep in touch between ground and rolling stock, the system decides a radio station, which can communicate with best signal quality. And the train pass that station, it hands over to neighbor station. We try 120km/h hand over test and we can communicate smoothly.

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This paper would explain concept and system of innovative train control and communication network for Shinkansen train, then examine best balance of performance, reliability, system redundancy, backup system, weight reduction and total cost performance. Test results of data communication on actual Shinkansen train set are also introduced. Finally, we would propose new total and optimum train set control method with train control and communication network for future Shinkansen trains.

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The new wave of signalling in Europe heralded by ETCS opens the opportunity to rethink and restructure the way railways do business. Swiss federal railways is embarking upon a program to systematically exploit the possibilities of that system to increase track slot capacity on its network. This paper reports on that program which has 4 key foci : 1. Streamlining of the ETCS technology itself to maximize resulting track slot capacity, 2. Systematic saturation of the network to maximise the effect on a network wide basis, 3. Flexibilising scheduling procedures to maximise the uptake of the newly available track slots, 4. Developing a new approach to rail traffic management to ensure the success of a dense future timetable. Swiss federal railways plan to increase its network capacity by 30% by implementing this program.

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Trains are often forced to decelerate or stop between stations on commuter lines because the preceding train has been delayed. If a train stops between stations, both the travel time and the interval between trains will increase. This situation has an adverse effect on energy consumption. To solve this problem. we propose a new train control method based on the prediction of train movement and data communications between railway sub-systems. Computer simulations are carried out to verify the effect of the proposed method, and it was proved that the new method reduces the train stopping time between stations and the energy consumption at substations.

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An ATC (Automatic Train Control) system with an autonomous on-board device had been developed to deal with flexibly : the variation of train performance; improvement of riding comfort; train speed-up; and reduction of headway. The brand-new ATC system is already put in service. Then, an integrated train protection system was developed by unifying said ATC-function wayside and electronic-interlocking function within a device. Developed technology is expected to reduce the replacing cost with aged signal equipment and also to improve the transportation performance of railway lines.

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The Tokaido Shinkansen will introduce a new ATC train control system which will enables more comfortable "continuous" brake control from existing system's "multistep" brake control. Compared from the existing system which receives allowable speed signal from the ground, this new system, with its main constituent of the control shifted to the device on the train, computes a necessary brake beginning point from the distance between the train itself and the train preceding. To secure high reliability, all devices on the ground and on the train are made of dual redundant composition. The devices on the train are also functionally redundant by adopting two sets of control unit. One is the operation control unit that chooses optimal brake notch. The other is security control unit that does the simple control only for the emergency braking. Each unit is working by different program. By realizing redundant composition at both the hardware and the software, we have attempted to improve its security level. This paper presents an outline of the Tokaido Shinkansen's new ATC system and its development status.

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This study, from the operator's viewpoint, combines the advantages of the headway adjustment models in both Middle and Heavy Rapid Transit systems in Taipei to develop a hat-curve straightening model to deal with the headway recovery problems when train delays occur. In the first step, a dynamic objective schedule is generated automatically for all service trains to catch up with. The model then updates the objective schedule step-by-step in order to gradually make the system recover from the delay situation.

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In order to reduce the wayside noise caused by passing high speed train, we have to clarify the noise sources and their characteristics and also grasp the contribution of each noise source to the overall sound level. We have been attempted to identify the noise sources by using counter maps of sound intensity level and grasp the contribution of noise sources from a noise profile of a passing Shinkansen train. Based on those data, we have developed a prediction model of Shinkansen noise. The prediction model calculates noise profiles during passage of Shinkansen train at a receiver point. The predicted noise profile agreed well with a measurement one for varied conditions.

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A hybrid statistical energy analysis (SEA) model for predicting the interior noise in a passenger cabin of a high-speed train was constructed. SEA parameters for the dominant transmission paths of the noise were estimated experimentally using the approximated power injection method (APIM). And parameters for the non-dominant transmission paths were obtained theoretically (for example, from the mass law). The passenger-cabin noise could then be calculated by the hybrid SEA model. This calculation was compared with the experimentally measured interior noise in a moving train. The comparison showed that the accuracy of the calculation model is 1 dB. It is thus concluded that this accurate hybrid SEA model can find the dominant paths of propagated sound and vibration in the passenger cabin and will, thus, lead to design of more comfortable highspeed train.

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Commuter train for Hong Kong KCRC were developed and manufactured as one of the worlds quietest train. This is achieved by the development series, such as 1) Noise measurement of the existing EMU, 2) Noise prediction 3) Comparison between the prediction results and criteria 4) Requesting noise criteria to sub-contractors 5) Making car body structure mock up and measurement transmission loss and structure borne noise in reverberant room 6) Manufacturing train and test it.

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By proceed various trials, the discharge of carbon oxide was decreased 5.4% compared the present with 1995. In addition to the strengthening of our stand with respect to environmental problems, we intend to direct continuous efforts, and introduce fully also about these trials with which we proceed prospectively, in this paper.

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The paper reviews the progress made during the research project "Low Emission Railway System (LERM)" funded by the German Ministry of Education and Research. The construction of test tracks and in-situ measurements of air-borne and ground-borne sound emission is carried out together with partners from academics (IASP at Humboldt University, Berlin), industry (Edilon, Munich) and from railway infrastructure operators (City of Munich). Modelling of the acoustic properties of ballast track and slab track superstructures is carried out at the University of Karlsruhe.

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Japanese rail has improved environmental performance while enhancing several sorts of transportation value. This paper describes how rail has conquered this inconsistency with some examples of Tokaido Shinkansen. In addition, the role which railroad should play in the traffic system and the efforts which rail hereafter should make are shown.

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This paper studied factors and effects of energy saving of Shinkansen trains, focusing on traction system change of innovative Shinkansen series 300 and 700. This study analysed contribution of regenerative brake energy and reduction of loss of running resistance for energy saving quantitatively. In addition, actual energy saving effect of high efficient trains was indicated by reduction of yearly electricity consumption.

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Compatibility between high speed running stability and good curving performance of railway vehicles has long been considered. In the design of vehicle parameters, the axle supporting stiffness is important to solve the problem. In order to realize higher level of compatibility, the authors propose the single-axle self-steering bogie based upon extending the theory of equivalent stiffness model into frequency domain. The proposed secondary longitudinal suspension mechanism replacing springs to dampers enables both of leading and trailing wheelsets to realize ideal curving performance on tight curved track while achieving high speed running stability. In order to verify the performance of the newly developed steering truck, experimental platform with 1/10 scale model vehicle is originally made. In this paper, the idea and theory of steering bogie are explained while considering the actual bogie mechanism consists of a single-axle bogie, bolster and yaw dampers. Experimental results using the scale model vehicle with two single-axle bogies show excellent performance in which creep forces are dramatically reduced while having enough hunting stability.

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According to the decrease of the three-axle bogie for locomotives in Japan, the need for diminution of the gauge widening in curved track has been pointed out by rail maintenance division. Meanwhile, bolsterless bogies which can have more steering ability are employed in many rail vehicles, and wheels with profiled tread have been used widely. For vehicles which have such bogies and wheels, it is expected that the gauge widening still keeps its effect on the curve negotiation even now. In this paper, the curving performance under the presence of gauge widening is investigated in detail considering the recent trend. The wheel lateral forces during curve negotiation obtained by numerical simulation are compared among vehicle types classified with truck mechanisms and wheel tread shapes. As a result, it is shown that the effectiveness of gauge widening exists for bolsterless truck and steering truck, but the availability to the trucks with profiled wheel is little because the change of wheel shape, from conical tread to profiled one, gives much effect on the performance. Then, a modification of shape in profiled tread is examined to get further availability of gauge widening.

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The structure of a high speed passenger car bogie is designed. The lateral semi-active damper for the secondary suspension is introduced . The stress of the bogie frame is analyzed by the use of finite element method in order to meet the requirement of strength at high running speed. The dynamic simulation of the bogie is undertaken and the ride performance of the bogie with passive damper and semi-active damper are compared. Finally, the roller rig test for the dynamic performance of the bogie prototype is carried out and the theoretical work is validated.

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The lateral mathematical model of a high speed vehicle system with 17 degrees of freedom is set up and the nonlinearities arising duo to suspension parameters and wheel/rail interactions are considered. The traction force in tension and compression cases which is the function of vehicle speed and position in the train set is also taken into account in the model. The critical speed at the Hopf bifurcation point on straight and circular curved tracks are studied by utilizing efficient numerical methods. The influence of track curve radius and superelevation on the critical speed is investigated.

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Railway vehicles of pneumatic suspension have a tendency to produce large wheel road variation on a twisted curve due to operation of the height control valve of air springs installed between both side air springs of the truck. In this paper, equations of moment equilibrium of the pneumatic suspension vehicle on the twisted curves are introduced quasi-statically, and effects of nonlinear characteristics of the height control system on the wheel load variation are analyzed. Analytical results are also examined by using the full size model test apparatus. The result shows preset pressure value of the air pressure balance valve plays an important role on the wheel load.

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This paper presents the curving performance of rail vehicles with air suspensions. Air suspensions sometimes cause reduction of wheel load at transition curve at low speed, so it is very important to evaluate the performance on transition curve. The air suspensions have non-linear characteristics, consequently that the performance might be influenced by the initial condition, the entrance transition curve condition and so on. In this study, the effects of track and running condition on curving performance at the transition curve section were examined by computer simulations and experiments using the full scaled one-car-modeled test bench. It was found that that the performance was influenced by the air flow through the levering valve into or out the air suspensions and the experimental results agrees with computer simulations. So it is effective to consider the characteristics of air suspension system to improve safety of running.

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The research was requested by Meridian Rail Corporation in United States. The Swing Motion Bogie can application by Korea style if synthesize study result of bogie strength evaluation, bogie dynamic characteristics analysis, actual test (maximum speed, derailment coefficient, lateral force, vertical force, vibration acceleration, steady state lateral acceleration) etc..

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This research was performed to examine the fundamental running stability of KTX (Korea Train Express) theoretically. Train set system consisting of 20 cars was the subject for analysis. Because train set consisting of 20 cars has so much DOF that commercial programs can't do modeling, 'in-house' program being able to assess the running stability of lateral of train set was developed and used for this research. Analysis was concentrated on the lateral motion of the train set. Analytical results were reported as the results of some important material property and conicity. In the end the characteristics of train set based on the analytical results were reported.

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To improve the ride comfort of tilting train, a lateral semi-active suspension system has been developed and subjected to a running test. Because to improve the passive tilting performance of tilting train, the resistance of tilting mechanism of typical Japanese trains are set up to small value. This feature gives many advantages on tilting performance of train, but it is a hard condition to apply a lateral semi-active suspension. To make an effective semi-active suspension system for the tilting trains, a changeable tilting damper has been developed and tested with semi-active suspension. As a result, the following have been verified. (1) The semi-active suspension without changeable tilting damper suppresses the lateral vibration of carbody about 20-30%. (2) Its performance becomes worse at the end of a traverse curve. (3) The changeable tilting damper improves the performance of semi-active suspension. (4) The combination of semi-active suspension and changeable tilting damper is an effective way to improve the ride comfort of tilting trains.

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To improve the riding comfort of high-speed trains, advanced semi-active suspension for railway vehicles is becoming more and more necessary. The goal of this work is to develop a semi-active suspension with better performance than the ones in current use, at a lower cost. By a reexamination of system design, a new type semi-active suspension utilizing electrical relief valves was designed and the cost of equipment was cut by 40%. Running tests of this system were performed on the Tokaido Shinkansen line and the test results assure that the new system is more effective at damping vibration than the ones in use.

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The advanced railway vehicles require a variety of technology and service for improving the riding comfort in the vehicle. One of them is to reduce the lateral vibration of the car body. Then we have developed an active suspension system and achieved success. Now we put this system to commercial use on Series E2-1000 Shinkansen cars as shown in Fig. 1 and Series E3 Shinkansen cars as shown in Fig. 2.

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