Using Global Navigation Satellite System (GNSS) is one of methods which a train detects its position by itself. It is required a preliminary evaluation for the accuracy of train detection position using GNSS on actual railways expected for application of GNSS. We proposed the evaluation technique for the accuracy of train detection position using GNSS and evaluated it with our technique on utility railways and streetcars. Now using GNSS is considered in the rail freight sector. We apply our technique for the accuracy evaluation of cargo handling forklift position detection using GNSS at the rail freight terminal station.

This paper introduces a study on the efficacy of an animal deterrent, the “Marine Saponin”, to deer in a real railway operation environment. This deterrent has been developed for years but has not yet been tested in the transportation aspect. The field experiment is explained, and the staged achievements of data acquisition and object recognition is described.

Vehicle localization is one of the important technical factors for autonomous vehicles on roads. The conventional methods use GNSS and/or visual sensors such as optical cameras or LiDAR. However, even the combination of existing methods has difficulty in some cases. Here, we propose a new method of using the environmental magnetic field (EMF) for localization. EMF consists of the Earth’s geomagnetic field and the local fluctuations caused by man-made objects. The proposed method includes using magnetic markers to enhance the accuracy of localization and building a 2-dimensional EMF map. The EMF map is constructed by Gaussian process regression. The proposed localization algorithm incorporates the Monte Carlo localization method. A simulation environment was built where a car-like robot ran through the EMF-mapped field while collecting magnetic field data and simultaneously localized the vehicle. EMF map was generated using actual sensing data as training inputs. Results showed that the proposed method can successfully generate a 2D EMF map and accurately localize the vehicle.

In this study, we propose a method for automatically generating driving routes for sections where no parcel lines exist, such as at intersections, in the production of high-precision digital road maps for automated vehicles. For route generation, the entrance and exit points of intersections are set based on recorded location information such as curbstones and white lines, and a driving route with smooth curvature change is generated by connecting the two points using a deflection curve of a beam. The beam deflection curve is calculated as a discrete element beam using a multi-rigid discrete element spring mass model. The generated path was compared with the paths in previous studies, and it was confirmed that the curvature change of the path was smooth and the bulge was small.

In recent years, the development of automated parking systems has progressed, and parking can be completed at the touch of a button. These automated parking systems are not applicable in urban areas or on residential roads where road widths are narrow. Therefore, this study proposed a route generation method that enables automatic parking even in parking lots facing narrow roads. The simulation results show that the proposed method successfully generates a route that reaches the target point on narrow roads. The proposed method was found to be useful in narrow parking lots, for example, to provide a space for drop-off.

The purpose of this study is to present the derailment behavior of a railway vehicle caused by an earthquake using a two-dimensional planar vehicle model including wheels with vertical flange. Equations of motion for the vehicle are established and calculated after defining wheel load, lateral pressure, etc. When a sinusoidal vibration is given to the track using the simulation, the motion of the vehicle, including the case of derailment, can be reproduced, and the results are generally equivalent to the 3D simulation for the limits of the occurrence of derailment. On the other hand, when the track is given large seismic vibration, no derailment occurs.

Differences in induced velocity models are made clear from experimental results of autorotation landing control by using two small helicopters with similar size and gross mass. In addition, a new desired trajectory of translational speed which is designed to reduce the descent speed and load factor at touchdown is demonstrated by flight experiments. By comparing simulation results with experiment results, the difference of the induced velocity can be approximately twice in spite of using airframes of the same size. Therefore, the design of the trajectory of the desired vertical velocity is changed and the suppression of the descent speed at touchdown is achieved; the flare starting altitude is reduced, and the formulation of the trajectory function is made to decelerate immediately after the flare started rather than to decelerate immediately just before touchdown. Furthermore, it becomes clear that the higher horizontal speed can further suppress the descent speed at touchdown.

A lot of vehicles pass through the main line road. Therefore, traffic jams occur when the traffic volume of vehicles increases rapidly, such as during commuting hours in the morning and evening. And when a traffic jam occurs, some cars will flow into the surrounding roads which will be as a “loophole”. In a previous study, the authors found that: vehicles that have entered a “loophole” will continue to drive on this road until the “loophole” connects to a road that makes it easier to return to the main line road, even in the section beyond which the traffic jam on the main line road has been resolved. The authors conducted a questionnaire survey of nearby junior high schools to clarify the places where they felt “dangerous”, and compared and collated places where sudden braking occurred using ETC2.0 data or places where traffic accidents occurred using GIS information. As a result, it was shown that the safety of roads designated as "loophole‘’ is declining, even in sections where traffic jam on the main line road has been resolved. However, in previous studies authors did not analyze in detail the following: regarding vehicles passing through the " loophole", the increase or decrease in the number of vehicles returning to the main line road is "linked to the traffic jam situation“ or the velocity of the vehicle traveling through the "loophole", etc.. In this study, as in the previous study, the analysis target was the road that was regarded as a "loophole" parallel to the section of the main road where the traffic jam was resolved. And the authors conducted a detailed analysis of the traffic routes and velocity of vehicles passing through the "loophole'' and the frequency of sudden braking, and evaluated the traffic environment.

At port container terminals, there's a significant traffic jam of outbound trailers at the entrance gate. To address this issue, the Port and Harbor Bureau of the Ministry of Land, Infrastructure, Transport, and Tourism has introduced a system called CONPAS (Container Fast Pass), which allows for reservations when carrying-in and out containers at these terminals. The primary goal is to reduce trailer wait times. In this study, we developed a discrete system simulator specifically for terminals that have implemented the carrying-in and out reservation function. Using this simulator, we evaluated the effectiveness of this reservation system. Additionally, we investigated how various factors, such as the percentage of trailers utilizing the reservation system and the conditions under which users access priority lanes, impact trailer wait times at different ports.

Interest in autonomous vessels has increased, and efforts to realize autonomous vessels are underway in Japan. One of the most important issues for the realization of autonomous vessel operation is the automatic collision avoidance navigation. Simulation is an effective method for developing such an algorithm, and this paper discusses the generation of a simulation scenario that takes into account the navigation area by using AIS information, which is traffic flow data in actual sea areas. First, using the entrance of Tokyo Bay as the target sea area, the characteristics of the sea area were determined by analyzing AIS data. Next, the procedure for creating a simulator scenario by extracting congested traffic flows from the AIS data was confirmed, and by using indices such as TCPA, it was possible to create a scenario that eliminated the subjectivity of the creator.

Hunting oscillation, a type of self-excited oscillation, is unfavorable due to its negative affect on both running stability and ride comfort. Hunting occurs at a certain speed even without any external disturbance. However, even below the hunting speed, hunting can occur when disturbance is input. The former study showed that there exists a clear point where initial lateral displacement of the wheelset causes hunting oscillation, and the point originates from unstable limit cycle. And it was also revealed that the limit cycle in question can be calculated by shooting method. Meanwhile, there could exist another type of steady state oscillation of which mode is different from the hunting oscillation observed on the previous study. Therefore, the author tried to apply the shooting method to calculate that type of steady state oscillation. This paper reports summary of the periodic solution calculated using the method and verifies the results by comparing them to the measured value. And it also discusses the relationship between the periodic solution and eigenvalue.

Evaluation for ride comfort in vehicle development is mainly performed by a testing expert who has been trained. Hence determining of which wheel receives road input is also determined by him when comfortable or uncomfortable vehicle vibration happens. If we can understand the relationship between input and output of the vehicle vibration quantitatively instead of deeming with human sensation, it could be one of ways that we understand human sensation for ride comfort more and it may lead to a development of new components and control methods which affect human sensation directly. Frequency analysis like Fourier transform, Short-time Fourier transform and Wavelet transform with magnitude-squared coherence are often used for finding the relationship between input and output signal. However those frequency analysis methods and magnitude-squared coherence aren’t suitable for non-stationary vibration like which is measured when a vehicle runs on rough road and off road. In this report the method to find the relationship between input from road and non-stationary output at a vehicle body is described with Hilbert-Huang Transform (HHT) which suits non-stationary and non-liner signals and ideas which comes from magnitude-squared coherence.

The motion of a linear two-wheel vehicle model is described using a one-degree-of-freedom damped vibration system with the rear wheel attack angle as a state variable. The transfer function of the attack angle of the rear wheel to the front steering angle input is the 0th order of the second order. Also，the numerator of the transfer function of the rear wheel attack angular velocity has only the first-order term. Using these two transfer functions，we interpreted the physical meaning of the numerator of the transfer function of the yaw rate and vehicle sideslip angle with respect to the front wheel steering angle. It was shown that each transfer function can be expressed by a combination of the turning (orbital) motion of the rear wheels and the rotational motion of the car body with respect to the turning trajectory.

4WS is a system developed to improve handling characteristics. In the tire linear region, the transient characteristics and sideslip angle of the vehicle can be controlled. However, 4WS is said to be less effective in tire nonlinear regions with high lateral acceleration. In this paper, the effects of 4WS in the nonlinear region were investigated using state transition vector diagrams. Unlike trial-and-error time-series simulations, the state transition vector diagram captures the entire vehicle motion state at each time. In the case of 4WS, the tire attack angle differs by the same amount as the rear wheel steering angle in all conditions. Therefore, 2WS and 4WS can be easily compared by shifting the state transition vector group left and right in parallel. As a result of the study, it was theoretically shown that 4WS can be on a more stable state transition trajectory than 2WS, and that it has a larger margin to reach the instability boundary.

We are developing a gyro-effect bicycle fall prevention device for the elderly to prevent them from falling or slipping. First, a simulation using a low-speed bicycle running model was used to evaluate the device, and a new machine was designed and fabricated based on the simulation. Then, the control design of the motor for flywheel swinging was conducted using simulation, and upright experiments were conducted to confirm the validity of the calculated gain values and to evaluate the assist function of the second prototype.

In the natural sciences, a common methodology is to observe phenomena, formulate a hypothesis, and verify it. However, human errors such as pedal mis-operation occur very infrequently, making it difficult to apply this methodology. Therefore, we established a method to artificially generate a pedal mis-operation situation on a driving simulator, and acquired video and driving data. In this paper, we extracted driver features from the accumulated data and investigated them. The results showed that aging slows down the transition from gas pedal mis-operation to correct brake operation. It was also found that the influence of driving frequency and gender was small. Furthermore, decision tree analysis was used to analyze the driver features that allow the driver to operate the brakes correctly even if there is a gas pedal mis-operation.

In order to reduce traffic accidents, it is necessary to take measures against accidents caused by the sudden appearance or sudden behavioral change of transportation participants. In this paper, we conducted analysis for two objectives: to clarify the most frequent patterns of the above accidents, and to understand driver’s behavior that avoided them. In the case of the sudden appearance, the most frequent pattern of a collision is a traffic participant's failure to yield the right-of-way at a blind intersection. Drivers who avoided the collision tended to keep their vehicle velocity low and/or decelerate before the participant was visible. In the case of the sudden behavioral change, the most frequent pattern of a collision is abrupt deceleration of a leading vehicle while driving straight and the following driver unaware of the change. Drivers who avoided the collision tended to reduce acceleration before the leading vehicle's deceleration. Based on these results, we are going to develop a driver assistance system measured to the above accidents.

One of the research issues for automated vehicles is path planning and following control. In a previous study, obstacle avoidance maneuver by the optimal path generator embedded model predictive controller (PG-MPC) was investigated. However, this study did not consider changes in vehicle speed and driving on a course with varying curvature. In this study, an optimal path generator that takes into account changes in vehicle speed is constructed, and a course coordinate system is used in the vehicle dynamics to enable driving on a course with variable curvature. The utility of the proposed controller is evaluated by both the numerical simulation and experimental testing of the obstacle avoidance maneuver of the micro-unmanned vehicle. Results show that the proposed real-time optimal controller successfully performs obstacle avoidance.

This paper addresses covariance control for a stochastic discrete-time linear system under correlated uncertainties. The covariance control problem with chance constraints can be formulated as a convex programming problem. Numerical simulations for uncrewed aerial vehicle path planning compare two control laws: covariance control laws considering correlated noise and non-correlated noise. Through the numerical simulations, it is verified that the covariance control law considering correlated noise generates a trajectory that satisfies the constraints appropriately. The effect of considering correlated noise within the covariance control law is clarified.

On ship navigation field, one of the most important operation is collision avoidance. To avoid collision, it is essential to acquire other ships. As of now, navigators’ eyes and navigational devices such as RADAR and AIS (Automatic Identification System) are used for the acquisition. Recently other technologies and devices such as image processing technology using deep learning, smartphones and LiDAR have been proposed as new sensors. It is worth to use multiple sensors to detect other ships. On the other hand, data fusion technology called as association is needed. In this paper, the characteristics of each sensor including advantages and disadvantages were described. As preliminary research, the gaps of distance between ships, direction, course over ground and speed over ground of the target ship based on RADAR data and AIS data on a ferry were shown.

The concept of the vehicle has changed with technological innovations on last decade. Today we can call these changes basically as "CASE" (Connected, Autonomous/Automated, Shared, and Electric)．The ease of product access on the user side and the mass production related works have increased worldwide production volumes. This issue has resulted in a greater demand for manpower in the sector．In addition，management， productivity and profitability related difficulties have occurred. In this project, improvements were made mainly around the productivity through the automation of "vehicle transfer operations in plant operations", which is one of a major problem and a manpower/hour consuming task. This system named as Remote-Control Auto Driving System (RCD)．The advance technology used system enabling unmanned, secured operations, were implemented in mass production environment earlier than the rest of the world

This paper describes a method for continuously measuring contact position between wheel and rail using strain gauges. Using the result of finite element analysis for instrumented wheelset, the author investigated the relationship between the bridge output and the change in the strain gauges attachment position and contact position (load position). From the obtained bridge outputs, the bridge output sensitivity rate was obtained. It is noted that the bridge output sensitivity rate is defined as the bridge output change per unit distance of the contact position. Based on the result, strain gauges position suitable for continuous measurement was identified. On the other hand, the relationship between contact force (wheel weight, lateral pressure, tangential force) and bridge output was also investigated. Static load tests were carried out on the instrumented wheelset with the strain gauges attached to measure contact forces and contact positions, respectively. It was confirmed that the test results generally agreed with the results of the finite element analysis and that the load position of each force influenced each bridge output, respectively. Finally, a method for calculating contact position by solving nonlinear equation is proposed, using contact variables obtained from the tests and a wheel rotation angle, bridge outputs, wheel load, and tangential force.

This paper presents the results of numerical analysis of the instantaneous temperature generated by frictional heat on the contact surface between wheel/rail during braking. Damage to the contact surface may occur due to wheel sliding during hard braking in wet conditions. The damage is generally considered to be due to changes in the mechanical properties of the wheel steel under high temperature conditions, however it was not clear to what extent the temperature rises from wheel sliding to wheel sticking. This study focused on the relationship between the temperature rise due to frictional heat generated on the contact surface and the coefficient of friction between wheel and rail, and estimated the instantaneous temperature rise on the contact surface between wheel/rail until the wheel sticks by combining the vehicle dynamics analysis using SIMPACK and the frictional heat analysis we developed. The results of numerical analysis showed that the instantaneous temperature rise on the contact surface generated by friction heat is the highest when the coefficient of friction between wheel and rail is slightly less than its adhesion coefficient, and that the smaller the coefficient of friction between wheel and rail, the lower the instantaneous temperature on the contact surface.

In recent years, the use of vehicles using electric motors for braking and driving has been expanding in rail and road transportation. At the same time, many attempts are being made to utilize autonomous and automated driving technology. From a safety perspective, vehicles that have the responsiveness and controllability of modern electric motors must be used with high responsiveness in mind. The purpose is to prevent passengers from falling during road and rail transportation. In this paper, the current status of transportation systems including railways was investigated. Actual data such as acceleration, deceleration, and jerk values from several commercially operated transportation systems were introduced. Furthermore, the concept of acceleration and deceleration was reconsidered.

Rolling stocks have tachometer generators on their axle ends. The only function of the tachometer generator is measuring rotational speed of the axle based on the frequency of the output signal. On the other hand, the amplitude of the output signal reflects not only the speed but also the gap between the tachometer-generator sensor and the axle-end gear. First, this paper shows that the amplitude of the output signal can change during running and the amplitude has a strong correlation with the position of the rolling stock. Generally, the sensor is fixed on the axle box and there is a small allowance between the axle box and the axle journal bearing. Therefor, the relative position between the axle box and the axle can change due to the interaction among the bogie, the axle, and the rail. This fact indicates the possibility that the tachometer generators can be used for some sort of anormaly detections. Based on this, this paper shows some experimental results of the anormaly detection on the rail by means of the tachometer generator.

In the case of long freight trains, there may be a delay in recognizing a derailment if a freight car that is far from the locomotive derails. In such cases, there is concern that the damage caused by the derailment may increase. Therefore, early detection of derailments is required. On the other hand, it is difficult to apply the derailment detection method using vibration acceleration sensors for passenger cars to freight cars. This is due to the unique characteristics of freight cars, such as the fact that they are subject to significant changes in running condition and running on a wide variety of tracks. Therefore, a derailment detection method applying mechanical contact sensors, which are easy to detect, was studied. The reason for considering the applying of contact sensors is that past studies have shown that certain parts of freight car bogies contact with other parts or rails during derailment. In this study, two locations were selected as the installation points of contact sensors on the bogies based on past findings and simulation results. Derailment detection tests were conducted by derailing a bogie with contact sensors installed at selected locations on a real track to evaluate the detection performance. As a result, it was found that the contact sensors were able to detect derailment immediately after it occurred.

Instrumented wheelsets are widely used in the railway industry for the purpose of measurement of the wheel-rail interaction forces, which are crucial factors in a running safety assessment. The lateral force, which is the lateral component of the wheel-rail interaction forces, is measured using bending strains induced on the wheel web in popular configuraions of instrumented wheelset. In addition to the use of bending strains, the author has proposed a new configuration of instrumented wheelset which usitilizes shear strains of wheel web as a measure of lateral force. In those principles of lateral force measurement using bending or shear strains, the measurement accuracy descreases when a loading point of wheel load, which is the vertical component of wheel-rail interaction forces, is shifted laterally since the wheel load also induces the bending and shear strains. In this research, output characteristics of several types of bridge circuits, which are categolized as “axially-asymmetric bridge circuit,” are investigated for the purpose of reducing the influence of wheel load and improving the measurement accuracy of lateral force. Static load tests are carried out and the results show that the axially-asymmetrization of the bridge circuits is effective to reduce the infuluence of wheel load.

In this study, an analytical investigation was conducted for the purpose of assessing whether commercially available wheelchairs have the potential to comply the requirements of aviation safety regulations in terms of structural strength under dynamic loading conditions. A manual rigid wheelchair for automobile use was used as a test article, and wheelchair securement system by means of holding an anchor bar was applied. Dynamic analyses of the wheelchair model using Radioss of the explicit solver were conducted on conditions of dynamic loading based on the aircraft airworthiness regulations. As a result of the analyses, the wheelchair frame and the anchor bar withstood the dynamic loading while the wheelchair caster broke down. The reason is considered improper material properties of the caster, and consequently a component structural test of the actual caster was conducted. The caster withstood the test and that means the caster is presumed to withstand the dynamic loading. Finally, it was determined that the structure of the wheelchair could comply the dynamic load requirements.