This paper describes two examples of human factors analyses on driver support systems: (i) a quantitative analysis on time-to-collision (TTC) using naturalistic driving data, (ii) a field operational test of the distance control assist system. The first analysis is to understand usual driving behavior in the real traffic condition and utilize the fundamental knowledge for concept making and design of driver support systems. The other is to identify changes in driving behaviors or driver's workloads using the system and clarify the system effectiveness. These kinds of human factors analyses are essential to the development of driver support systems.

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In order to realize smooth curving of LRV, active steering control of railway bogie with indepedently rotating wheel is discussed. In previous study, smooth curving is realized with feedback and feedforward control whereas high speed running stability still problem to be solved. In this study, a roller rig test bench is developed so as to validate the effectiveness of proposed bogie control and structure.

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Flywheel was considered as long life and high energy density auxiliary power source in hybrid traction system of railway vehicles. However, it is necessary to evaluate the gyro-dynamic interaction between current vehicle and additional flywheel. This paper proposes a new method on tilting control of railway vehicles using gyroscopic moment obtained from onboard flywheel primarily used as auxiliary power source. Uncontrolled pendulum railway vehicle cannot neutralize sensory lateral stationary acceleration in transient process. In order to prevent comfort deterioration in transient process, active control torque is necessary. Differing from conventional methods, we utilize gyroscopic moment of flywheel in hybrid powered railway vehicle. We developed a simulation model of railway vehicle considering onboard flywheel as a controllable gyroscope. Controller consists of feed-forward and energy needed for the control was calculated by numerical simulation.

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In recent years, the tilting vehicle of air spring type, which uses air springs as the car-body tilt mechanism, has been employed even for Shinkansen trains to speed up on curved sections. In this study, with an analytical model of the tilting vehicle of air spring type, numerical simulation is carried out to investigate the high-speed curving behavior in the compound curve. Then, anti-roll damper, which is equipped between the car-body and the existing anti-roll device, is examined as a counter measure. As a result, it is shown that the vibration phenomena occurred in compound curves is caused by the centrifugal force due to the vertical curve and the unbalanced stiffness between the right and left air springs for the car-body tilting, and that the anti-roll damper has a potential to reduce the car-body vibration increased in the compound curve.

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In order to improve the lateral riding quality of railway vehicles, various type of Full-Active or Semi-Active Suspension Systems have been developed and in use. Semi-Active System is announced more useful in energy saving and fail-safe than Full-Active System; but the efficiency of Semi-active System is half of Full-Active System and is none in the crossing section. So we have been researching new control method to improve the skyhook Semi-Active System. One of our trials is a Collaboration Control of Semi-Active damper and Short Stroke Actuator in series connection. As a result, we have achieved the decrease of lateral acceleration to the level of Full-Active System with small energy.

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The motion simulator we call "Vehicle Dynamic Simulator" can regenerate train ride comfort exactly. It has been used for development of Tokaido-Shinkansen effectively. On the other hand, vibration of high frequency attracts our attention as train ride comfort gets improved. To solve the problem, the performance of the Vehicle Dynamic Simulator is improved by broadening the band of motion. To realize the high performance, the model cabin is newly made as smaller size. Another point is a controller which can compute much more data. As a result, it can generate vibration up to 90Hz. Using this simulator, maintenance of railway, reduction of noise through the floor of cabin, and development of seats are promoted.

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This paper describes the analysis of the vibration characteristics of backrest in high frequency domain. In this paper, running test, impulse hammer blow test and 3D shaking table test are carried out in order to clarify the dynamic characteristics of the seat with backrest of a high-speed vehicle, for example Shinkansen bullet train, and measurement test are done to identify the support stiffness of backrest. In addition, the analysis of the backrest vibration from the numerical simulation is compared with the test results. The numerical analysis model produces 10Hz translational vibration and 30Hz torsional of the backrest. The results from numerical analysis are compared with experimental analysis for model validation. In conclusion, the mechanism of vibration occurrence of the backrest is clarified.

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Vertical vibration (including high frequency vibration) of Tokaido-Shinkansen is tangible with the improved lateral riding comfort, maximum speed and body stiffness. However the seat for Shinkansen that can suppress high frequency vibration effectively isn't developed, because it isn't clear why vibration on several parts of the seat is greater than that on the floor. Therefore we investigated the vibration characteristic of the seat for Shinkansen, both the seat frame and the cushion, using Vehicle Dynamic Simulator. The results show that because of the sympathetic vibration of the cushion and the seat frame, vibration on the seat is increased compared with that on the floor.

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We investigated the vibration characteristics of Shinkansen seat by performing vibration tests with tri-axial shaking table. By measuring the vibration accelerations of each parts of the seat and table floor under the seat, frequency response analysis and modal analysis were conducted. In the frequency response analysis, we introduced the multiple inputs frequency response function. We also identified the modal characteristics such as the natural frequency and mode shape of the seat. From these analyses, effects of human on the seat and number of the input on the vibration characteristics are discussed.

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A simulator for railway vehicle floor acceleration was devised by combining a universal shaking table and an inclination table. By the simulator riding comfort can be evaluated. The shaking table cannot produce sufficient amplitude in the region of lower-frequencies. Combining the inclination table that uses gravitational acceleration by inclination and the universal shaking table, railway vehicle floor acceleration can be reproduced. That is to say, the inclination table takes a part for lower-frequencies, and the universal shaking table takes part for higher-frequencies. We show the folding frequency which enables the simulator to reproduce railway vehicle floor acceleration properly.

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As the maximum speed of high-speed trains increases in Japan, flow-induced vibration of trains in tunnels has become a subject of discussion. In this paper, we report results of a study on use of modifications of train shapes as a countermeasure for reducing an unsteady aerodynamic force by on-track-tests and a wind tunnel experiment. First, we conduct a statistical analysis of running test data to identify the parts which affect unsteady aerodynamic force. Next, we develop a wind tunnel test to measure unsteady aerodynamic force acting on a train in a tunnel and examine train shapes with a particular emphasis on parts listed by the statistical analysis. The wind tunnel test shows fins under the car body are highly effective to reduce the unsteady aerodynamic force. Finally, we test the fins by a running test and confirm its effectiveness.

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One of the aerodynamic issues affecting high-speed trains is the flow-induced vibration of the tail car when cruising through a tunnel, which results in reduced passenger comfort. The objective of this study is to develop a method to evaluate the fluid force acting on high-speed trains. We conducted wind tunnel tests of a simplified train model using a flat plate to simulate the effect of the tunnel wall. Pressure transducers were used to measure unsteady pressure fluctuations on the tunnel wall, and Pressure Sensitive Paint (PSP) was applied to measure time-averaged surface pressure distribution on the train model. We also conducted Large Eddy Simulation (LES) for the same model and test conditions. The results indicated that by applying LES, we were also to reconstruct the spectrum of pressure fluctuation on the tunnel wall that we observed in the wind tunnel experiment.

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Compression waves, generated when a high-speed train enters a tunnel, were examined by scaled model experiments and numerical simulations. We used two nose models with different cross-sectional variations. Model experiments were carried out with train models traveling between 270 and 300 km/h, and the pressure changes in the tunnel were measured. It was found that the nose of model2 had a lower maximum pressure gradient than that of model1, which means that the nose of model2 performs better for micro-pressure waves. Numerical simulations running at the same speed were also carried out. Pressure and pressure gradient at the same tunnel surface location with the experiment were calculated. Maximum pressure gradient difference between the calculation and the experiment was within 5%.

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We investigated the microstructure of the brake rotor used in service, and the re-heated specimen in order to clarify the effects of heat process on the micro structural change of brake rotor. 1) The microstructure of brake rotor transforms to austenite crystal forms when heated to the point of AC3 transition temperature. Since the austenite crystal size in steel becomes larger in proportion to heating temperature, heat history of the used brake rotor can be presumed by measuring the crystal grain size of the rotor. 2) When the brake rotor is heated to the transition temperature, the refinement of grain size and the phase transformation occur simultaneously. The crystal size of white layer is smaller than that of re-heated specimen, which seemes to be caused by the dynamic recrystallization due to strain on the white layer. 3) Analysing the surface temperature of the brake rotor using the infrared thermography revealed that the brake rotor temperature rises locally at the hot spot when braking. The analysis also enabled us to estimate the maximum surface temperature of the brake rotor at braking

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We conducted a research on reducing weight under the spring of the Shinkansen rolling stock. As a way of reducing the weight, we developed a new brake disk made of Aluminum alloys instead of conventional steel. The conclusions are as follows. 1) A lining for the aluminum disc is newly developed. By softening the lining and by improving the contact surface condition of the lining, we were able to stabilize friction coefficient from the initial braking and also prevent temperature rise during braking. 2) The new hybrid brake disc using MMC for sliding surface and AC4CH for matrix was developed. The optimum thickness of the MMC was found to be 7mm from visual inspection and the shape measurement after testing. 3) The brake testing was performed using the new lining and the new brake disc in sets. We measured the friction coefficient, disc temperature, lining temperature and the amount of lining wear. We believe these data are useful in putting the new lining and brake disc into practical use in the future.

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At the time of the Niigata Chuetsu Earthquake, Shinkansen derailed for the first time in our country, but was able to prevent the secondary damage by the derailment because the train did not deviate largely from the track and stopped miraculously. In this article, the behavior of the buckling phenomenon of a train was analyzed likely to occurred after the derailment by the numerical simulation. And to reduce the damage by the derailment by the earthquake, the inspection results are derived that was performed by the 1/87 reduced scale model train experiments. To act on each coupler force to the pulling side by the braking force of the later vehicles is important, not to cause the train-buckling phenomenon.

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Performance of acceleration or deceleration of railway vehicles is limited to adhesion force. It is well known that adhesion factor between wheel and rail tread has some difficult characteristics; one of them is its descending tendency with the ascent of rolling speed particularly under water lubricant condition. We need to know these characteristics as quantitative descriptions, and arrange them to an easy-to-use way for design of running gear such as powering or braking devices. In this paper, a measurement technique on operating train and an advanced evaluation method of the adhesion coefficients are introduced.

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Most of the bogies used for LRT have independently rotating wheels (IRW) so that the floor of the passenger compartment can be lower. IRW, however, do not have a sufficient ability to self-steer, and generate large lateral forces in curved sections of track. The EEF (a German acronym for Single-wheel Single-running-gear) bogie, on the other hand, has IRW that have the self-steering ability. The nonlinear profile of the wheels creates the gravity stiffness that gives them their self-steering ability. In this paper, a multibody dynamics model of the vehicle is developed, and a numerical simulation is conducted. Experiments with a 1/10 scale model vehicle has also been developed. From these results, a design method for the self-steering mechanism of a railway bogie, considering the nonlinear effects of linkage arrangement, is proposed.

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An elevator rope for a high-rise building is excited forcibly by the displacement of the building caused by earthquakes and wind forces. In this paper, simplified calculation method, single degree of freedom (SDOF) system, for estimating rope deflection during earthquake is presented by using building's acceleration. Finite difference analyses of rope vibration are also performed to verify the validity of this simplified calculation method. The calculated results of this simplified calculation method is in fairly good agreement with that of the finite difference analyses.

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Elevator ropes for a high-rise building are excited forcibly by the deflection of the building caused by wind forces and earthquakes. In this paper, Rope Swing Model, from the displacement of upper extremity of the rope to the displacement of middle point of the rope, is expressed as Multi-degree of Freedom model. And the damping coefficient of rope as model parameter is identified by experiments of free vibration. We compare the analysis results of the Rope Swing Model to experimental results using plural ropes by shaking test. Analysis results of the Rope Swing Model are in fairly agreement with the experimental results.

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Hinged-leg type continuous unloaders in which each leg on the sea side is fixed by a pin to the main body are often used for bulk handling in sea ports. For such type of unloaders, we proposed an antiseismic device using linear ball bearing and laminated rubber bearing installed between the traveling gears and the fixed-legs on the land side. Vibration experiments using 1/15 scale model of an actual unloader, and transient response analysis were conducted to evaluate the analysis method and the performance of proposed antiseismic device. From experiments under the El-Centro, Hachinohe and Port Island seismic waves excitation, with using the antiseismic device, the response acceleration was as low as 5 to 12% compared with the case without the device.

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In recent years, electromagnetic suspension, which absorbs vibration as electric energy, is being developed. It has many applied functions such as damping, actuator, energy regeneration, and sensing, and thus many researches are conducted. These researches were focused on the control methods, nonetheless there are few researches considering vehicle characteristics. In this research, torsional of the body frame, which is one of particular traits of a heavy vehicle, is considered. The torsional body is modeled as a continuous cylinder, therefore differences of roll angles of the front and the rear axis can be expressed. The authors propose to install electromagnetic actuators in suspensions of a large vehicle. With electric circuits coupled with electromagnetic devices and supplied electric energy, electromagnetic actuators can reduce torsional movement of the body frame to improve the maneuverability and the stability of the heavy vehicle. The effects of electromagnetic suspensions on the performances are examined through numerical simulations.

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This paper aims to formulate a method of estimating distances and velocities between platooning vehicles from a few vehicles' accelerations in the platoon by using Kalman filter. At the beginning of this paper, seven vehicles are assumed to they are platooning in a row, and two of them are able to measure their accelerations. Secondly, a state and measurement equations of Kalman filter are formulated by defining the distances and velocities of all seven vehicles as state variables and the accelerations of two vehicles as measurement variables. Besides the formulating, the coefficient matrices of the two equations are analytically derived. Although the estimate accuracy of this approach has not been confirmed, this paper theoretically establishes a method of estimating the distances and velocities between platooning vehicles from the measured accelerations in the platoon.

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This paper suggests that pavement irregularity is extracted from the acceleration data by independent component analysis (ICA). ICA is method to divide an original signal from mixed signals. Eight accelerometers are set up, and measured unsprung. The road is a tile road, and the road input is one response. Therefore, as ICA processing result, one waveform by the tile unevenness is divided. Even if the composition of the vehicle is changed, pavement irregularity is extracted. From PSD of wave form extracted by ICA, the peak frequency is different on dry road and wet road.

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Recently the technology of active safety that prevents the traffic accidents is developed. In particular, electronic control technologies such as ABS and DYC are developed remarkably. The performance of these control systems are influenced a great deal by friction between tire and road. Therefore grasping the road condition leads to improve the performance of control system and safety technology. There is a road friction coefficient such as parameter that determines road condition. The road friction coefficient is needed to estimate, because it is difficult to measure. In past studies, it was estimated by IMM method and brush model identification method. In this study, it is estimated by Bayesian Network that is stochastic model. Result of simulation and experiment, effectiveness was confirmed.

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The steering assist for the automobile gives possibility that the emergency avoidance performance in the human-vehicle system can improve. This paper examines about the variable characteristics steering system which can change the dynamic properties of the steering system as the steering assist system. Various composition of the variable characteristics steering system can be thought of but we analyze the characteristics of the way of using PID control by the computer simulation. As a result, it is clarified that the P-element and the D-element contribute for the emergency avoidance performance to improve.

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This study seeks to design a lane keeping controller for motorcycles and to evaluate it by using a rider control model. We applied the optimal control theory to evaluate a lateral displacement at a virtual point ahead of the vehicle. By examining the computer simulation with the rider-in-the-loop system consisting of the motorcycle, the controller, and the rider control model, good lane following performance is achieved without interference between the control input and the rider's input. In addition, the virtual point regulator corresponds to not only the steering torque disturbance but also the lateral force disturbance by choosing the distance to the virtual point.

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We have developed a new steering control system in order to reduce a driver's workload in parking maneuver. In this paper, a concept of the system and an outline of the steering control method are described. Then, effects of a control logic which is applied to solve a characteristic problem of the system are verified by simulation and actual vehicle test.

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In this study, the four-wheel steering to handle follow-up control of a bus lane. Vehicles with two goals before and after the course and to detect a deviation, according to Difference around the steering wheel angle for separately. In the current system with PID control, but the road running by Kant, such as disturbance of the difficulty of improving results. Therefore, control of multi-input multiple-output system in recent years, researchers have been getting a lot Sliding-Mode have tried to apply control.

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Recently, Light Rail Transit attracts attention as urban traffic system of the next generation, because it is economical and clean. In order to realize barrier-free design, LRT often has independently rotating wheels. However bogie with I.R.W. is hard to keep running neutral position. To keep running neutral position, it is required active steering control method. In previous research, feedforward control and feedback control were proposed. Using feedforward control, the bogie cannot run neutral position on rail track which has irregularity. Using feedback control, the bogie becomes oscillating in straight section running under the big feedback gain. This paper proposes introduction of the learning control and experimental results with scaled model vehicle show the effectiveness of learning control.

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We propose new vehicle dynamics management of in-wheel electric motor vehicle based on tire force usage rate. In the vehicle dynamics management, we adopted non-linear optimizing controller using direct yaw-moment control, tire force usage rate and each tire force. In cornering performance test simulation of 3 degree freedom model, we confirmed that by using this vehicle dynamics management, saturating tire force could be avoided and higher critical speed also could be achieved. We did the simulation and the run test by the in-wheel electric motor vehicle. By these simulation and run test, it was confirmed that the 4 wheel drive in-wheel motor electric vehicle with the proposed vehicle dynamics management system could have higher stability performance comparing to the same vehicle without control.

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A newly developed parameter design procedure for generic control systems based on Quality Engineering is applied to the design of 2-DOF vehicle steering controller. The controller has 15 design parameters need to be determined for improved vehicle performance. The proposed procedure makes it possible interactive design of the controller using sensitivities on design parameters considering trade-offs among objective functions with low computational cost. Results of statistical evaluation using Monte Carlo simulation and time-series data show that the designed controller has high robustness to variations in vehicle parameters and improved stability in limit maneuvering region.

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We have proposed yaw moment observer (YMO) for a direct yaw control (DYC) of electric vehicles (EVs). So far, we applied YMO to various yaw-rate control systems, and verified the effectiveness of these systems. However, because it was possible to experiment only in the campus of the university, the robustness of YMO was not examined in high speed region. The dead time of yaw-rate sensor and variation of vehicle inertia influence the yaw-rate control system based on. So, in this paper we consider the robustness of YMO in high speed region by simulations and experiment.

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