In railway vehicles technologies, to provide a comfortable ride quality is an eternal challenge. However, a mechanical suspension design has the technical limits to improve the ride quality. To break through this issue, we have developed the active suspension from 1990s and as the result of these studies, the pneumatic active suspension as the 1^st generation and the electro mechanical active suspension as the 2^nd generation were put into the practical use on JR EAST Shinkansen and the conventional line express trains in Japan. In this paper, the author reports the configuration and development history of the active suspension in Japan.

The Autonomous Transportation ARM (Academic Road Map) Research Working Group formed inside the JSME Technology Roadmap Committee. The purpose of the Working Group is the trial of collaboration activity between many divisions of JSME. The activity is concentrated in forming the two-dimensional Academic Road Map named 2D-ARM. Industrial revolution is studied at the same time.

In order to obtain insight about weave phenomenon of wheel set of rail vehicle, this paper starts with formulating its natural frequencies and damping ratios. Interpreting these formulas, this paper points out that larger ratio of creep coefficient normalized by wheel set mass reduces the weave at lower speed than a given speed and the smaller ratio does it at higher speed.

This paper deals with a parameter design for a nonlinear hunting motion of a railway wheelset. If a railway vehicle runs under a critical speed, a hunting motion might occur by an effect of a nonlinearity of a hunting motion. In order to remove a factor for hunting motion under a critical speed, a nonlinear analysis of a hunting motion was carried out. In order to analyze a nonlinear hunting motion, equations of motion with third-order polynomial approximation based on a single axle truck was used. A center manifold theory was applied to the equations of motion and equations of motion of a normal form were derived. An equation of a limit cycle amplitude was obtained using the equations of motion of the normal form. By using the equation of a limit cycle amplitude, a relationship between an amplitude of a limit cycle and vehicle parameters were considered.

In this this work, the bogie pseudo-hunting motion of a reduced-scale model railway vehicle, running on doublecurved rails is theoretically and experimentally investigated. Bogie hunting motion occurs for the real railway vehicles (e.g., bullet trains) during running on straight rails at high travelling speeds (e.g., 200-300 km/h) and long wavelengths (e.g., 20-30 m). Since due to the speed and space limitations, such conditions cannot be duplicated in laboratory, a pseudo-hunting motion was induced by employing convex-concave curvilinear rails. Firstly, the test rig, the system of vibration measurement and ride-comfort evaluation, and the experimental procedure are described. Next, a model to clarify the kinematics of the carriage and bogies, as well as, the stroke of the yaw damper, against the particular geometry of the curvilinear rails, is suggested. Resonant peaks observed on the recorded vibration spectra during the travelling of the vehicle, on straight and double-curved rails, are interpreted based on the natural frequencies of various elastic elements used in the construction of the railway vehicle. Ride-comfort is evaluated according to the ISO 2631 standard, and also by using the specific frequency weightings (filters) that account for the discomfort sensation, during the reading and writing activities.

In recent years, railway system is attracting attention in terms of energy efficiency and environment friendliness. Rail of railway is one of the most important elements in constructing railway system. Railheads are subjected to severe contact with wheels during repeated passage of vehicles. As a results of severe contact with wheels, wear of rail or rail defect have been occurred on railheads. Rail profile will be changed due to wear development. Worn profiles of rail have changed complexity in each section because the condition of wheel / rail contact has changed gradually, according to the running condition of vehicle and track geometry condition. It is very important to predict the worn profiles of rail based on the analysis of vehicle dynamics. Previously, we constructed the predicting model of worn profiles of rail with SIMPACK. In this study, we conducted the wear test by use of a full-scaled wheel / rail rolling contact equipment to distinct the coefficient of wear and to measure the worn profile for validating the prediction model.

It is important to predict the development of rail and wheel wear. However, the observation of wear development in practical railway systems requires a great deal of time and cost, so, that is not an efficient approach. To predict the wear profile of wheel and rail, numerical procedure with the aid of Multi-body dynamics software is proposed in this paper. We propose a model for the prediction of wear development by embedding the proposed model of wear development into Simpack. First, from the motion analysis using Simpack, the contact pressure, slip ratio and some necessary parameters are obtained. To create worn profile of rail and wheel, the wear depth is derived using the proposed model. The current profile is updated by worn profile, and set as the new profile in Simpack model. The wear depth is calculated based on Archerd wear theory. Calculation of wear development is performed in Wheel/Rail contact area, and nodes are replaced with the calculated wear depth. The present study investigate the validity of this worn profile prediction model. These results of model analysis are compared with the result of experiments which obtained previous study. Wear coefficient, depth and amount are discussed from the viewpoint of mechanical and tribological contact problems.

Brain Computer Interface (BCI) is a system that controls machines and devices by extracting neural information from human brain activity and it is expected for nursing robot such as an artificial hand. Near Infrared Spectroscopy (NIRS) is a measurement method using near infrared light for detecting brain activity. However, NIRS signal has noise and trend which disturbs detection of brain activity. In this study, we propose a signal processing method for improving detection accuracy and carried out the detection experiment to compare previous method and proposed method. The experimental results show that the proposed method is effective for NIRS-BCI system.

Helicopter has an emergency landing function that is called autorotation. Autoratation is a maneuver that we can land safely in case of engine failure. It is carried out by pulling down collective pitch (average pitch angle of blade) in order to keep mainrotor’s rotational speed. However, autorotation is said to be very dangerous because failure is equal to an accident. So it is considered that automation of it leads to grow helicopter’s safety. In this paper, aiming at automation of autorotation, flight dynamics of a small scale helicopter during autorotation is analyzed to improve our dynamics model. For that, 2 mainrotor downwash models are focused on and precision of them are analyzed by 2 types of analysis: one is by autortation flight data, and the other is by the calculation result of downwash distribution using CFD tools. In the former analysis, dynamics of thrust and attitude is considered with developing an approach to remove wind influence, and succeeded to improve the precision of dynamics model. In addition to that, the latter analysis showed that the effect on adding downwash distribution to dynamics model is large enough to change the downwash model.

Electric Vehicles (EVs) are penetrating into the market as countermeasures against environmental problems. Electric mileage is use to change sensitively affected by driving conditions. Therefore, mileage measurements in real driving conditions and accurate mileage simulations are in great concerns of EV users. Mileage measurements are normally done in some predetermined pattern driving. Accurate running resistance measurements to analyze mileage are used to done in special simple pattern tests. The authors introduced running resistance measurements in “usual driving conditions” for EVs. This study evaluates the measured data in “usual driving conditions” by comparing with the data in a “simple pattern test.”

An off-road two-wheeled vehicle runs at the dart road surface which tends to be slippery including the steep slope and unevenness mainly. An analysis method of the movement limit of the vehicle and its operation conditions suitable for a movement analysis under these conditions was considered. It was focused on movement of a longitudinal direction of a vehicle and formulated the movement limit which considered the friction coefficient and the road surface slope by basic physical law. Data measurement by an all-Japan top-ranking rider was performed. It could be confirmed that data is distributed in the reach of the assumed movement limit. There is also a possibility that the movement limit of the vehicle and the operation conditions can be grasped by measurement in an off-road two-wheeled vehicle.

Research of the motorcycle dynamics research of linear motion has been done many. However, there are few in regards to nonlinear motion. As a cause of the one, it is to have difficult analysis becomes complicated equation. When considering the motorcycle safety, there are many nonlinear motions that have to discuss. In this research, investigate for vehicle motion characteristics in the non-linear region of the motorcycle. As a first step, we constructed the equation of motion in order to perform the study of the motorcycle nonlinear.

In the case of four-wheeled vehicles, as a method to indicate the cornering limit performance, the G-G diagram is used. In a G-G diagram the longitudinal acceleration and lateral acceleration of the vehicle are set as the two axes. A visible outline of the data when the vehicle is being driven at the limit is drawn on these axes to show the height of the cornering limit. Further, another type of G-G diagram that also indicates which of the front or rear wheels have reached their limit has been proposed. Since the height of the cornering limit, as well as which of the wheels has reached the limit at that time will all be discussed for the cornering limit performance of the motorcycle, it was determined that this G-G diagram should also be suitable for studying motorcycles. However, this G-G diagram cannot be applied to motorcycles as is. This is because the yaw moment balance conditions are different for motorcycles and four-wheeled vehicles. During the cornering of a four-wheeled vehicle, there are two yaw moments acting around the center of gravity of the vehicle due to the cornering force of the front wheels and the rear wheels. However, during the cornering of a motorcycle, there is another yaw moment that acts on the vehicle in addition to these two yaw moments. This third yaw moment is due to a braking and driving force. Therefore, in this paper, the three moments acting on the motorcycle will be converted into the two moments that act on a four-wheeled vehicle so that this G-G diagram can be applied to motorcycles. Further, the front wheel braking force distribution ratio that would produce the maximum height of the cornering limit was studied to propose a criterion assuming combined brake system (CBS) control during cornering.

Because of the limited payload and cost-performance, GPS/INS hybrid navigation system is general on small unmanned helicopter. However when GPS wave is blocked, the precision of the measured position is not guaranteed and GPS navigation-based flight control fails. One of the solution for this problem is to use Air-data Sensor (ADS), which measures airspeed. In addition, using airspeed for automatic control improves robustness for wind disturbance. This paper describes the development and the verification of the airspeed sensing and navigation system to cope with these problems by using ADS. An ADS, which has lightweight Pitot tube made from 50mm length acrylic resin on the head of the helicopter, is produced. And GPS/INS/ADS hybrid navigation system based on Extended Kalman-filter is designed by the sensor model built from the measured data on flight experiment of the ADS. By verifying GPS/INS/ADS hybrid navigation system for estimating airspeed and redundancy for invisibility of GPS, the improvement of the precision is restrictively confirmed when GPS wave is blocked. However, some problems are found; the estimating is possible only when the helicopter goes forward, and deteriorated by down wash. To solve these problems, new ADS, which has honeycomb structure for straightening flow and orifices for measuring wind angle, is produced. From the experimental result of new ADS, some points to notice are examined for the future design; inflow to Pitot tube should be kept fully, it should be designed under streamline shape, and prevention of turbulence is required.

For practical use of autonomous driving vehicles, technical development has been promoted. And the systems are planned to use a road map data in addition to sensors information to autonomous driving system. In ZENRIN Co., the road map data has been studied the method of obtaining road curvatures using a vehicle trajectory that was measured by using a mobile mapping system. However, calculated curvatures include fluctuation component because of wobbles caused by vehicle characteristics and road geometry. So, this study proposed the description method to obtain curvatures without fluctuation component. The proposed method consists of two processes. The first process estimate curvature-changing-points. And in the second process, curvature changing points are moved exploratory so that a maximum deviation between a vehicle trajectory and a generated trajectory from estimated curvature-changing-points is minimized. In order to investigate the appropriateness of the proposed method, it was verified in different scenes. As a result, the proposed method was confirmed that is possible to obtain non-fluctuation curvatures within an allowable error in the all scenes.

Autonomous driving in highway uses lane markers detection with stereo camera, LiDAR, and radar. However, when we drive in the city, an intersection has no lane markers, so we cannot detect them. Therefore, we need control method without using lane markers detection. We propose a method to drive right/left cornering in an intersection with smoother steering. We use self-position data from GPS and map information composed of nodes and links of road. First, we generate target steering angle, which follows vehicle trajectory to clothoid curve from map information. Next, we calculate gain value, which leads commanded steering angle to target steering angle by least square method. Simulation results showed that we can generate commanded steering angle, which makes vehicle trajectory to clothoid curve in any corner with gain value we calculated.

This study discusses the lane-keeping performance of the stability control for multi-articulated vehicles. The vector follower control system is applied to multi-articulated vehicles to stabilize the trailers. The effects of the vector follower control system are evaluated by examining computer simulation with the driver-vehicle system which consists of the multi-articulated vehicle model, the vector follower control system and the driver model. The vector follower control system improves the stability of the trailers, while the system deteriorates the lane-keeping performance under the lateral disturbance. In addition, the lane-keeping-assistance system is also applied to the multi-articulated vehicle with the vector follower control system. The lane-keeping-assistance system improves both the stability of the trailers and the lanekeeping performance.

It has become more necessary to find a way to fly safely under turbulence since external disturbances are still major cause of the air traffic accidents. One possible solution for this problem is to develop a control advisory system for pilots using wind speed information ahead of the aircraft measured with the Doppler LIDAR. This paper mainly focuses on how to calculate such control advice from the LIDAR information. We propose a control advisory calculation based on the Energy Principle. It provides advice to control the longitudinal aircraft dynamics from the viewpoint of the mechanical energy, a concept that is intuitive to pilots. In order to understand the Energy Principle, the aircraft’s equations of motion will be derived starting with the mechanical energy transformation law. Owing to the Energy Principle, the thrust controls the mechanical total energy and the elevator distributes the total energy between the kinetic and potential energies. The total energy and the energy distribution are fed back to calculate the control advice. For evaluating how well the proposed system calculates suitable control advice, numerical simulations were carried out. The results clearly show that the preparation of the energy for the expected wind shear can be achieved.

If the automation surprise occurs in Intelligent Transport Systems, the driver and the vehicle may run into a dangerous situation. In this paper, the condition of the occurrence of the automation surprise in case of following the preceding vehicle in the curve road is explored by the driving simulator experiment. A smart glass, which is new warable device, is also used as a human machine interface to prevent the automation surprise and the validity is clarified.

This study examines the driver assistance system informing the necessity of deceleration at a signalized intersection ahead during the red signal. The assistance system indicates the evaluation indices on the road ahead virtually or with the onboard monitor in the own vehicle. The driving simulator experiments are carried out to compare the on-road indication with the onboard monitor. The on-road indicaton shortens the driver’s reaction time to the emegancy deceleration of the precceding vehicle. The proposed system helps the driver to decelerate earlier and avoid the higher deceleration. These effects make it possible to suppress the collition risk to the precceding vehicle.

This paper proposes and evaluates mathematical models to predict driver’s deceleration intent. Assuming a four-vehicle convoy, an unscented Kalman filter (UKF) integrated with a car-following model attempt to estimate the headway and velocity of all vehicles in the platoon. The car following model used in this research is the conventional Gazis-Herman-Rothery model (GHR model). Then, another GHR model is used to predict the deceleration intent of the preceding car based on the estimated headways and velocities of the platooning vehicles. In addition, this study proposes an interface how to inform the predicted intention to the following vehicle by using a windshield display (WSD). A numerical analysis showed that the UKF integrated with the GHR model succeeded in predicting the intention accurately. The WSD interface should be designed more precisely and driving simulator experiments will be carried out to evaluate the performance of the proposed system in the future development.

Because of construction of skyscrapers, ultra-high-speed elevators have been developed to carry people faster. The buffer applied for the ultra-high-speed elevator is very long because the buffer's stroke is determined by the speed. Generally, some experiements are necessary to develop a new buffer. But, in the case of very long buffers, it is difficult to repeat some experiements because it takes time to manufacture. To reduce the number of the experiements, it is important to predict the result of the experiement. This paper shows the dynamics analysis model developed to evaluate the dynamics characteristic of the buffer applied for the ultra-high-speed elevator, and verification of the model by the experiment.

Programmable electronic system (PES) is spread to much industrial fields like car, railway and so on because of establishing functional safety standard IEC61508 in 2000. There are some discussions to PES for elevator safety devices in Japan. To computerize safety devices, new safety system using PES is developed. The proposed system is focused on the safety devices on overspeed protection, and the system computerizes the safety device using dual encoder. To detecting failure on dual encoder, there are two methods that one is to stop in a moment by comparison, the other is to continue the safety operation after detecting a failure.

This paper describes wind analysis results in a ropeway installation and simulation results of carrier responses to wind gust. A carrier collision accident happened in a ropeway installation in 2015. One of the accident causes is pointed out to be wind gust. This report has its beginning with overview of the accident and brief results of our accident investigations. Analysis results are also reported for wind direction and wind speed which were measured in the ropeway installation after the accident. In addition, simulation results are reported for carrier swing when wind gust acted to the carrier. Finally this paper provides control charts to wind gust in this ropeway installation.

In this study, the relation between the thermal environment and thermal comfort of passengers in a main line vehicle in summer was investigated. At first, to understand the characteristics of the thermal environment in a main line vehicle, a field survey was conducted by measuring the temperature and humidity in regular passenger services from the morning to the night. The observation range of the temperature was from 23℃ to 28℃, and that of the humidity was from 38%rh to 68%rh. Then, to obtain the fundamental data about the passengers’ thermal comfort, a subjective experiment in which 44 subjects in total participated was carried out. The subjects rode a main line vehicle stationed at a rolling stock center, and they experienced the temperature changing approximately in the observation range in the field survey and answered questionnaires about their thermal comfort. Furthermore, the relationships between the thermal indices called PMV/PPD and the subjective evaluation values were analyzed. As a result, it was indicated that the error of the PPD in predicting the percentage of dissatisfied subjects became large in the range PMV>0, where the effect of the sweat sensation became significant. However, the PPD agreed well with the actual percentage of people who reported feeling ‘slightly cold’, ‘cold’ or ‘slightly hot’, ‘hot’. Our results suggest that the PPD can be used as an index of the variability of thermal sensation, but not of thermal comfort in a main line vehicle in summer.

Linear Chuo Shinkansen is expected to bring an economic impact on areas along the line as well as all over Japan.This study applies spatial computable general equilibrium (SCGE) model for the quantitative estimate of an economic effect created by the construction of Linear Chuo Shinkansen, and examines its impact on local communities. Linear Chuo Shinkansen provides fast connections between regions and creates a large metropolitan area. An economic impact of ¥300 billion is expected in the inaugural year (2027) when Tokyo-Nagoya stretch opens, ¥590 billion by the time Tokyo-Osaka stretch opens (2045), and ¥12.7 trillion by the 50^th anniversary of the opening of the entire route. Tokyo is estimated to benefit most, far exceeding other areas along the Linear Chuo Shinkansen route, leading to further agglomeration of economic and business functions as well as cultural activities in Tokyo. Issues of Linear Shinkansen trackside areas, the social environment development that takes advantage of regional characteristics, is how to achieve.

With the electrification of the automobile, requests to the measures of brake noise and drag has been increasing more and more. In the future, it will be need to consider measures from the functional design which is more upstream stage in order to respond to the required accuracy. In the stage of functional design, firstly, it is important to elucidate the fundamental mechanisms and it needs model which can be represent the mechanisms. In this paper, we reproduced the theoretical model of brake squeal by using a physical model based on 1DCAE which is one of the effective method in the functional design. Then, we considered about the two possibility to deal with more complex phenomenon by extending the reproduced model. One is effect of the pressure dependence of the pad rigidity. As a result, we showed that even if the system is in a stable state in the initial state, depending on conditions, the system changes in an unstable state. Another is consideration of multiple mode. We reduced the degree of freedom of cantilever FEM model and disc FEM model by using a reduction technique of FEM model and applied them to physics model. As a result, we showed the unstable mode changes by the combination of eigenvalue of cantilever and disc. Finally, we verified the friction point position δ₀ by creating a FEM model of disc brake. We were able to confirm that the center of contact of pad and disk deviates from the center of the shape.

In automobile brake systems, high friction coefficient pad materials are required for mass reduction of economic run. Brake noise problems are sometimes caused by high friction coefficient pad materials. Therefore it is very important to make a research of brake noise. In basic experimental brake squeal research, chattering noise was also observed. In the future, there is a possibility of chattering noise caused by high friction coefficient pad materials and mass reduction. This paper describes the basic research of chattering noise 0.5 kHz. First chattering noise vibration mode is shown here. Next, theoretical analysis of chattering noise is shown here for understanding of its mechanism. As a result, chattering noise is considered to be caused by dynamic instability due to frictional vibration. This research describes how to reduce chattering noise, such as reduction of the friction point offset, increasing rigidity of cantilever, arrangement for no coupled vibration between cantilever and disc.

In recent years, increment of speed and power of automobiles, railways and aircrafts contribute to be required high load power, durability and safety for the machine parts. In the automotive industry, it has been advocated to secure competitiveness by quiet and comfort of the car. However, complex friction vibration resulting from the pursuit of high-functionality has become a problem frequently. In particular, in the disc brake, although braking and safety driving at high speed driving has been demanded, still vibration problems that occur have needed to be solved. In late years, in these development trends, the problem of new vibration that called hot judder that produce heat occurs frequently in disc brakes. However, the automotive industry has not been clarified also generation mechanism not only prevent method because hot judder has phenomena due to heat and vibration. Also, in previous study, hot Judder cause a buckling due to thermoelastic instabilities (TEI) over time by causing disc and brake pad induce thermal expansion to unevenness the contact force. However, studies from the viewpoint of the self-excited vibration with thermoelastic due to friction has not been researched, the generation mechanism of hot judder is not clarified. We deal with hot judder as one of the pattern formation phenomena that is occurred a self-excited vibration with time delay, and clarify the generation mechanism of the vibration by an analysis model.

Since acoustic emissions (AEs) are elastic stress waves resulting from deformation and fracture of materials, the detected AE signals include a lot of information from deformation and fracture phenomenon. The AE waves generated from the interaction of frictional surfaces can be detected as AE signals using an AE sensor attached to the objective material. Although friction force is mostly used for the evaluation of frictional properties of tribomaterials, it is difficult to gain high sensitivity because the rigidity of the friction system could easily be changed by the installation of a spring. On the other hand, the AE signal measurement has a high sensitivity against microscopic deformation and fracture phenomena comparing with frictional resistance measurement. In this study, the relationships between the frictional properties and the AE signals were examined in two experiments: the in situ observation experiments with a pin-on-block sliding friction tester and the long sliding distance experiments with a pin-on-disk-type sliding friction tester. It was found from the results that microscopic deformation and fracture between the sliding surfaces are mainly caused by a crack growth (slip deformation) and separation of brake pad materials, abrasion of the rotor material, and adhesion of metallic fiber to the rotor material. The difference in the fluctuations of the AE signal is caused by the rapid fracture immediately under the sliding surface. In addition, the fluctuations in the AE signals increase because of the deformation and fracture of the tribofilm. It was also found that the average friction force has a correlation with the AE signals mean amplitude value because the amplitude of AE signals vary with the scale of the phenomenon.

The virtual reality technologies, such as Virtual Reality, Augmented Reality, and Mixed Reality are reviewed and the perspective of the driving simulator along with the technologies are discussed. Using the Head-mounted display “Oculus” and the stereo camera device “Ovrvision”, this paper introduces the MR-oriented driving simulator, in which the stereo camera image of the front view of the driver is processed by the chromakey technique to replace the green-screen with the computer graphics of the outer view of the driving car. This feature of the system will be rather useful for the simulators of bikes and bicycles, which require to show the view of all around, than that of cars.

Recently, driving simulator(DS) has been widely used in various research fields such as assessment of traffic safety countermeasure. To be used at more diverse research areas, it is important to improve realistic sensation of DS. In this paper, we have focused on driver’s cognition status for sign and information boards in highway. By using measurement of cortical brain activity, we will analyze data. With data from analyzing, we will compare real car experiment environment and DS experiment environment and find mechanism to improve the realistic sensation of DS.