This study proposes an inverted pendulum-type tilting rail car with stable body motion by oscillating a weight, to which the phenomenon called Kapitza's pendulum is applied.The stability of its motion is predicted by using the method called time-averaged method. The proposed method is modeled on a simple bogie frame - body model to predict the stability of the car body motion.The simulation results are compared for each condition to confirm that the prediction is highly accurate.

The trolley contactors installed on trolley wires are used to detect streetcars' positions and control their routes. The passage of a streetcar is detected when the pantograph contacts the mechanical switch of the trolley contactor. This requires periodic maintenances in high places, which are heavy burdens. Global Navigation Satellite System (GNSS) has been considered as an alternative to the trolley contactors. The accuracy of GNSS varies greatly depending on the surrounding environment. It is necessary to evaluate the accuracy of streetcar position detection using GNSS in advance. We propose the evaluation technique for the accuracy of streetcar position detection using GNSS.

When level 2 automated driving is put to practical use on general roads, it is expected drivers have to take over driving more frequently as the road environment is more complex than on highways. Then three types of Human Machine Interfaces, HMIs, were proposed to support the smooth takeover from the automated driving. Two driving simulator experiments were conducted to evaluate them. In the experiments, 15 and 16 participants were asked to take over driving at the signalized intersection on the general road, and the results were evaluated based on the vehicle motion, the gaze of the participants, and the questionnaire. As a result, it was found the proposed HMI reduced the maximum deceleration and speeded up the takeover process.

Monitoring the condition of railway tracks effectively increases the safety of railways. A system that uses a compact on-board sensing device was previously developed for monitoring the track condition of railways. The system's position identification method uses GPS map-matching.However, this system had an error of several tens of meters depending on GPS reception conditions. In this study, the position correction method was tested using curvature calculated from yaw angular acceleration. The results of the test study indicated that it is possible to diagnose the location of track irregularities more clearly.

A minimal risk maneuver (MRM) stops a vehicle in a case when an event occurs that interferes with safety driving such as a driver unwellness, system malfunction, or unforeseeable events in the driving environment. Appropriate stopping methods for each MRM tigger have been considered, such as evacuation to a safe zone or stopping in the same lane, depending on the situation. However, few studies have compared and evaluated the influence of different stopping methods on the surrounding traffic flow. In this study, this manuscript evaluates the impact of the stopping methods on traffice safety and efficiency by traffic simulation.

In this study,we propose a method to automatically design driving lanes in the section where no lane lines exist, such as intersections, with the intension of using it in the process of producing high-precision digital road maps for automated driving vehicles. The lanes are generated by setting the entrances and exits of intersections based on the location information of landmarks such as curbstones and white lines recorded in the high-precision digital road map, and connecting the entrances and exits using deflection curves of beams to which distributed loads are added to generate travel lanes with smooth curvature changes. The travel lanes generated by the proposed method were compared with the routes in previous studies, and it was confirmed that the curvature change of the continuous curvature lane at the start and end points is smooth.

The passenger of vehicles experiences a variety of vibration and sound stimulation from the surrounding environments. We are exposed to an environment with vibration and noise generated simultaneously in vehicles such as automobiles and trains. This study investigates the effect of sound on vibration sensations such as strength and uncomfortable sensations. This report focused on the difference in sound volume change that cannot determine the superiority of vibration and sound. We report the results of measuring the vibration sensation when exposed to horizontal whole-body vibration and sound by a psychological questionnaire.

In railways and buses, air sterilization equipment is required to reduce the anxiety of passengers to infectious diseases. For this reason, the air sterilization equipment using UV-C LED with a peak wavelength of 265nm has been developed for applied to railway’s air conditioners.

In order to improve sterilization performance, ultraviolet irradiation intensity of the internal space of this air sterilization equipment was investigated using the lighting analysis software. As a result, we confirmed that the UV irradiation intensity could be 2.6 times as a condition with a curved surface, a reflectance of 0.90, and an offset of the LED. Additionally, it was confirmed that the spatial illuminance decreased as the directivity angle of the LEDs increased. This result means that it is more effective to narrow the directivity angle by applying the lens on the LED than the loss caused by the lens transmittance.

Finaly, the sterilization performance of this air sterilization equipment have been evaluated for floating virus. As a result, the higher reflectance conditions decrease in the virus concentration than the low reflectance conditions. It means the inactivation effect is increased by increasing the reflectance. And also, it means that it is possible to inactivate the virus in the air in the train by installing this air sterilization equipment inside the air conditioner for the railway.

Railways running in the Tokyo metropolitan area have the problem that snowfall and snow accumulation can cause disruptions to timetables. In order to solve this problem, the mechanism of the running resistance force acting on wheels rolling through granular material is investigated using a scale experimental running resistance meter. Results of previous studies have shown that a rolling model wheel generates a greater running resistance force than a non-rolling plate. In this report, the running resistance force acting on the non-rolling model wheel is measured and compared with the result of previous studies.

Driving a car is a complex task involving a series of cognition, judgment, and action processes. When the driver falls into a state of fatigue, it is thought that human error is caused by the deterioration of these processing capabilities, leading to traffic accidents. This study aims to establish an index to quantitatively evaluate the physiological and psychological fatigue of the driver and occupant during automobile moving. In this report, we report on the fatigue of the driver and the occupant during 3-hour continuous driving, which was examined from both physiological and psychological responses in the actual vehicle experiment.

In this study, as basic research toward the automation of aircraft taxiing, we developed an automatic running system using position information. Specifically, the travel position correction program developed in the previous year was improved to a program that uses two P-controls to change the amount of movement of the servomotor based on the amount of deviation from the straight route and the difference in the direction the aircraft is facing. As a result, it was confirmed that the improved traveling position correction program worked properly, but the amount of motion needed to be further examined. Future work includes adjustment of the proportional gain, improvement of the traveling position correction program for traveling in a curved line, installation of the automatic traveling system on the model aircraft and traveling experiments using the model aircraft.

It is crucial to grasp dynamic characteristics of leveling valves (LV) and differential pressure valves (DPV) used for railroad vehicles when discussing the dynamic motion property of the vehicle, in particular the running safety. From this viewpoint, it is desirable to evaluate the LV and DPV responses while they are actually mounted on the vehicle. However, the test method which able to evaluate such responses have not been established yet. In this paper, the author proposes a stationary test method to evaluate in-situ responses of LV and DPV by utilizing “pneumatically controllable leveling rod.”

Tangential forces caused by micro slippage between the wheels and rails of a railway vehicle are referred to as creep forces. Creep forces play a significant role in the dynamics of rolling stock, and therefore must be properly understood. Scale model wheel machines can simply measure the creep forces, however the problem is that the scale model rules of the creep force characteristics between the real and the model vehicles has not yet been established. In this study, longitudinal creep forces were measured using scale model wheels and rails as a basic study for establishing dynamically similar creep force characteristics in scale model wheels and rails. A device was developed to add micro running resistance torque by connecting a motor or electrical resistance to the axle, and the relationship between longitudinal slip rate and longitudinal creep force in the micro-slip region was investigated and is reported.

When the vehicle system controls in automatic driving and driving assistant, it is important for the system side to match the driver. In this study, in order to examine the characteristics of driving preferred by the driver, we extracted by using driving simulator, characteristics of driving that the driver subjectively felt was good and investigated the items that are important when judging whether driving is good or bad.

In this study, dynamic maps are being constructed for the road stability of autonomous vehicles and vehicles equipped with ADAS (Advanced Driver-Assistance Systems), which are currently undergoing demonstration experiments. Tire and road surface friction characteristics, which govern vehicle motion performance, are important, and a database is being built to add road surface characteristics data, which vary in various driving environments, to the dynamic map. In previous research, a measurement method of road friction coefficient and an estimation method of road friction characteristics were proposed. However, there is a problem that the overall estimation accuracy is affected by the estimation accuracy of the coefficient of friction at the time of tire lock, and the estimation accuracy decreases. Therefore, in this paper, the friction coefficient, at the time of tire lock is estimated by the estimation method from the correlation between each coefficient of Magic Formula and the curvature of the friciton characteristic. This paper describes the results of an attempt to improve the estimation accuracy of overall road surface friction characteristics. In the future, we will ivestigate wheter the method studied can be used for other tires. Also, we will study vehicle dynamics control using the database constructed by using these method.

When an elevator rope for a high-rise building is forcibly excited by long-period ground motion, rope displacement becomes large even if the ground acceleration and the buildings acceleration is small. Therefore, in order to prevent damage to the elevator, an accurate estimation of rope behavior is required. This paper introduces the following topics;(1) relation between damping factor and magnification factor/response curve of rope (string model), (2) vibration characteristics of rope (string model) with vibration suppressors, (3) estimation method of 3 parameters (equivalent flexural rigidity, viscous damping ratio, structural damping ratio) of rope (beam model).

Instrumented wheelset is widely utilized for the measurement of wheel load and lateral force between wheel and rail. Those forces are fundamental quantities in the context of running safety assessment of railway vehicles. The calibration of instrumented wheelset is implemented by applying force to a certain point on the wheel tread, while there exists a variety of contact conditions between wheel and rail in running. A testing apparatus is proposed in order to clarify characteristics of strain output of instrumented wheelset which depend on the contact condition. The overview of the testing apparatus and an example of test results is described in this paper.

In recent years, the handling volume of 40-ft ocean high-cube containers has increased in logistics in Japan. In Japan, the height of 40-ft ocean high-cube containers limits the number of sections where they can be transported by rail. To solve this problem, it is necessary to develop a new freight car with a cargo bed height of 700 mm, which is 300 mm lower than a conventional freight car (cargo bed height: 1000 mm) currently in use. For this purpose, a new carbon fiber reinforced plastic (CFRP) model secondary suspension spring with a lowered spring height has been developed to expand the possibilities of lowered bed height.

Previous research has shown that the CFRP model secondary suspension is effective as a space- saving spring and have nonlinear spring characteristics. This report, the performance model bogie with a lowered bed height with the CFRP model secondary suspension attached was evaluated using a three-dimensional vibration table. As a result, the CFRP model secondary suspension was found to have better vibration dampening than coil springs.

The purpose of this study is to build an evaluation method of a railway running safety more realistically using information about contact condition between wheel and rail in a railway vehicle. To achieve this purpose, the authors have proposed an estimation method for motion variables of a wheelset and friction coefficient between wheel and rail by observer based on a Kalman filter using a single-wheel creep-force model with an instrumented wheelset. In the previous studies, the authors mainly have examined effectiveness of the proposed method using numerical simulations but scarcely have been carried out investigation using measurement data. This paper reports the results of the validity test of the proposed method using the measurement data and simulation data mimicking them. The verification results show that the proposed method managed to estimate reasonable values of the friction coefficient, the lateral displacement of the wheel/rail contact point in outer side and the angle of attack in the curve section to some extent.

Steer by wire technology realizes a change of relationship between the steering wheel angle and the tyre steer angle in accordance with the running state of the vehicle or the environmental conditions during driving. In this research, a variable characteristics steering system (VCSS) using the steer by wire is proposed. Fuzzy control is used for the control of the VCSS. A computer simulation assuming an emergency avoidance situation is performed. According to comparing the vehicle with the VCSS to the normal vehicle, the relationship among driver's operation characteristics, vehicle motion, and each parameter of the VCSS is investigated. The possibility of improving emergency avoidance performance is found.

This paper considered the effect on the stability limit of adding roll motion to the equation of motion under force control.．The results show an increase in the unstable region compared to the stability limit under force control without the addition of roll motion. Increasing the roll stiffness and decreasing the roll angle approached the stability limits under force control with no added roll motion．Therefore, it seems that the roll angle generated by the roll motion affects the stability limit．

The centrifugal pendulum vibration absorber (CPVA) is developed to suppress the torsional vibration of automatic transmission. However, the natural frequency of the CPVA varies due to the nonlinear when the vibration amplitude of CPVA is large. To overcome this problem, a new physical pendulum type of centrifugal pendulum vibration absorber is developed. Physical pendulum type of centrifugal pendulum vibration absorber is possible to rotate depending on the control angle. In this study, the optimal design for the physical pendulum type of centrifugal pendulum vibration absorber is discussed by changing the parameters such as the link length ratio and the control angle.

In order to solve the problem regarding the shortage of truck and bus drivers in recent years, manpower-saving and unmanned operation of commercial vehicles is currently being actively researched and developed. However, when traveling on narrow road widths and curves with large curvatures, such as urban roads, commercial vehicles have larger internal wheel truck differences and overhang swing than passenger cars. Therefore, the path tracking control focusing on CG position tracking applied to passenger cars cannot be applied directly to commercial vehicles. Therefore, the purpose of this study is to develop a path planning and motion control system for automated operation of commercial vehicles in urban areas. In designing the control system, a risk potential field was used to express the driver's sense of danger with respect to obstacles and road boundaries. A simulation is conducted on a course that recostructs a real intersection, and a parameter study is conducted. Finally, the simulation results of this method are compared with those of a general path-following method, and the results show that this method is effective for avoiding obstacles in intersection situations.

A method of controlling the acceleration required for merging between the vehicles on a main road was investigated. The vehicles on the main road usually keep speed near junctions. In order to prevent collisions, at the time of merging, the speed of ego vehicle, and the inter-vehicle distance of object vehicles on the main road and the distance to the merging point are measured previously. Using these parameters, we derived a calculation method of the acceleration required for safe merging between the vehicles on a main road. In addition, as the acceptable upper and lower limits of the vehicle's acceleration are defined. It is possible to predict whether the vehicle can safely merge with acceptable acceleration/deceleration.

In recent years, explosions caused by homemade improvised explosive devices, known as IEDs, have occurred while vehicles are in conflict area. Therefore, as one of the measures to prevent IED damage, research and development of a vehicle body structure to prevent the occupants is necessary. In a previous study, an explosion impact was applied to the bottom centre of a vehicle body, which is a reduced model of a vehicle body, and the reaction of the vehicle body model was discussed. However, actual explosion accidents do not only occur at the bottom centre of the vehicle body, so this study is confirmed the reaction of the vehicle body model when the position of the impact is changed and contributes to future consideration of the vehicle body structure.

In Japan, the vehicle-cyclyist collisions at blind intersections account for approximately half of all traffic accidents, and the fatal accidents are more frequent at night than during the daytime. One technology that improves the visibility of vehicles at night is the use of road surface projection lamps. The purpose of this study is to investigate the effect of the road surface projection lamps on increasing the safety margin of cyclists in avoiding crashes at blind intersections. The methods of the study are based on (1) numerical simulation to calculate safety margins under assumed scenarios and (2) data analysis to calculate safety margins under events extracted from the near-miss incident database. The results s visualized the potential of the road surface projection lamps in increasing the safety margin of cyclists.

One of the major important issues in road traffic safety is to reduce the number of vehicle-cyclist (or pedestrian) collisions at blind intersections with poor visibility. Relying on information of speed limits, an Intelligent Speed Assistance system (ISA) indicates the speed limit information to the driver or performs a control intervention to avoid exceeding the speed limit. The purpose of this study is to investigate the effect of compliance with the speed limit by the ISA on reducing the number of vehicle-cyclist collisions, by using near-miss incident data at blind intersections. The investigation is based on the visualization of a safety margin observed as drivers adjust their vehicle speed to a given road environment context. First, the relationship between the vehicle speed and the safety margin was analyzed. Next, the effect of guiding the vehicle speed to the speed limit on the reduction of collisions under hazardous events of smaller safety margins was analyzed. Finally, this study investigated limitations of the effect of ISA-induced speed reductions on vehicle safety. The main finding of this study was that the ISA-induced speed reductions could lead approximately half of hazardous events into acceptable events with the enough safety margin.

This paper presents a method for simultaneous localization, mapping, detection, and tracking of moving objects (SLAMDATMO) using LiDAR and IMU set on a helmet of micro-mobility rider. An environmental obstacle map built by SLAMDATMO represents stationary objects, road boundaries and road surface conditions in roadway and sidewalk environments. This map can be used to active safety for micro-mobility, such as bicycles, e-bikes, and e-scooters. Distortion in the LiDAR scan data is corrected by estimating the helmet’s pose (three-dimensional position and attitude angle) based on the information from Normal Distributions Transform (NDT)-based SLAM and IMU. The road surface, boundary, stationary and moving-object scan data are classified from the corrected LiDAR scan data. The moving scan data are used for DATMO, whereas the stationary scan data are used for point-cloud mapping. The boundary scan data are used to detect obstacles, such as curbs, gutters, and steps. The road surface scan data from LiDAR are in conjunction with IMU, and potholes and humps, such as manhole cover and cracks, are detected to reduce the falling risk of micro-mobility. The experimental results in a road environment of our university campus show the effectiveness of the proposed SLAMDATMO method.

The Tokyo University of Agriculture and Technology has a database that collects driving data in near-miss situations. The database is intended to be used f to investigate the causes of human error through accident analysis, to verify the functions of new driving support devices and to do etc., but there is a problem that the speed of the driving data has a low resolution. The purpose of this work is to study a method to estimate the vehicle speed with high resolution and high sampling rate using the acceleration and speed of the driving recorder for utilization of drive recorder speed data. Estimation was performed using the least-squares method and the Kalman filter. In each estimation, speed data was used in two different ways. The performance of these four methods was compared and evaluated. The comparison showed that the least-squares method produced the smallest error in the four estimated velocities. The estimated vehicle speeds by this method were used in the near-miss database.

Research and development are actively conducted for recent advances in the self-driving and unmanned vehicles, along with further efficiency and safety. In such fields, obstacle avoidance is frequently addressed in control applications through the concept of active safety technology. This paper investigates the real-time optimal obstacle avoidance control that the optimal path generator embedded model predictive controller. By offline computation, a large number of optimal obstacle avoidance control solutions are calculated to generate the supervised learning data for the deep-learning neural network used for the optimal path generator. Then, constructed optimal path generator is embedded in the model predictive controller to generate the reference command for the tracking task during the optimization process. 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.

Since the limit performance of an integrated chassis control vehicle depends on the combination of control inputs such as steering angle, braking torque, and so on, it is important to clarify how the combination of control inputs affects the limit performance. In this study, the performances of integrated chassis control systems with various input combinations are evaluated in an obstacle avoidance situation. The obstacle avoidance problem is formulated as an optimal control problem that maximizes the avoidable obstacle width at the predefined distance and is solved by using a numerical optimization technique. In the optimization, a full-vehicle model equipped with actuators that can independently control the steering angles, braking torques, and active suspension forces of four wheels is used, and the optimization results are compared for various combinations of control inputs. From the optimization results for four combinations of control inputs, the effects of integrated control are examined.

It is difficult for drivers to prevent pedal misapplications by themselves. In this paper, we propose a system that immediately informs the driver that he/she is pressing the accelerator pedal by means of a tactile vibration of the pedal. An eccentric motor mounted on the back of the pedal generates a constant vibration with a fixed period only when the accelerator pedal is depressed. An experiment has been conducted with a driving simulator to investigate whether the pedal vibration system is effective in preventing pedal misapplication accidents and whether it is accepted by drivers. We induced pedal misapplications on a driving simulator and observed reactions of experiment participants. As a result, it was found that the pedal vibration system allowed drivers to notice pedal misapplication more quickly and to correct their foot position more rapidly. Therefore, the pedal vibration system is effective in preventing accidents caused by pedal misapplications. However, many experimental participants felt discomfort while driving.

The most famous and tallest volcano in Japan is Mt. Fuji. If the volcano erupts, volcanic ash accumulates on pavements and affects to travelling of vehicles, such as causing them to slip and get stuck. Therefore, we collected data by driving over volcanic ash spread on paved roads with a vehicle equipped with instruments that can measure the force applied to the running tires. We used three types of volcanic ash with different grain sizes and cover thickness. The experiments were conducted at constant speeds of 10 to 40 km/h and at rapid acceleration and deceleration. Data were collected not only on flat straight roads but also on curved roads with a radius of 30 m. From these data, the characteristics of rolling resistance, driving force, and side force on an ash-fall road surface can be obtained. This paper presents the driving roads on which the experiments were conducted and the effects of volcanic ash on driving by processing the tire data obtained. As the rolling resistance increases according by thickness of the volcanic ash increases, but as the driving speed increases, the rolling resistance tends to decrease.

Methods for reducing lift force of conventional pantographs in a crosswind were investigated using large-eddy simulations (LESs). In our previous study, wind tunnel tests and numerical simulations using a full-scaled pantograph were carried out, and the mechanism how the lift force increase in a crosswind was clarified. There are mainly two mechanisms: one is a stational large-scale vortex generated on the upper surface of the pantograph head, and the other is positive pressure generated on the lower surface of the pantograph head. In this study, LESs were carried out using a modified pantograph head shape based on the mechanisms described above, in order to investigate methods for reducing the lift force of the pantograph head. As a result, the lift force decreased in the cases of a shape with a diagonal cut on the lower surface of the pantograph head, and a shape with an opening sections on both the upper and lower surface of the pantograph head. The former shape generates a negative pressure area under the pantograph head, while the latter shape attenuates the large-scale vortex on the upper surface of the pantograph head. Thus, they achieve the lift reduction by different mechanisms and can be used together. The lift reduction rate reaches approximately 60% when both methods are used together, indicating that this is an effective method for lift force reduction.

In recent years, inverted pendulum personal transporters ( PT ) which have excellent visibility and operability have been used mainly in Europe and the USA, but accidents due to driver inattention have been reported. Therefore, a driving assistance system is needed to help the driver notices obstacles. In the evaluation of driving assistance systems, experiments using simulators are important to ensure safety and to unify conditions. The aim of this study is construction of a simulator and applying it to safety performance evaluation of driving assistance systems. In order to simulate driving in a actual PT, a PT model is constructed using simulator software that moves according to the driver's centre of mass. The view of the PT model is projected. The behaviour of the PT model was compared with the actual PT to evaluate its reproducibility. An evaluation experiment was conducted with a driving assistance device mounted on the control interface. The PT model drives toward the obstacle in the simulator and the driver applies the brakes when the driving assistance device is activated. Drivers were surveyed after simulated driving. Braking distances were compared with speeds.

The authors have been developed a flow-field integrated adaptive control system, which use in-flight surface pressure fields for real-time flight control. A simple mechanism for dynamic wind tunnel experiments is designed to run design and evaluation cycle for flow-field-integrated flight control. This system is not a tethered system using wires, but a yaw-rotatable seesaw system in which a lightweight aircraft model is supported from the lower fuselage at the center of gravity position. In this paper, we first explain the mechanism of the dynamic support system. The equations of motion of the model airplane on the support system are then derived, and the accuracy of the model is verified by comparing the motion quantities by simulation experiments and wind tunnel experiments. Once the validity of the simulation model is verified, the control law can be brushed up by repeating the design and verification cycle that goes back and forth between control law design by simulation and demonstration in the wind tunnel.

Vehicle motion is realized through forces generated between the tires and the road surface and is closely related to the road surface. Steering torque generated at the steering wheel due to forces from the road surface and friction in the mechanical system is important information for understanding road surface conditions and driving conditions. In this study, we attempted to reproduce the steering torque characteristics in a simulator that takes road surface inputs into account. The force that the tires receive from the road surface during driving was calculated. This force was input to a multibody model of the steering system, and the resulting steering torque was output by the simulator. The simulator's reproducibility was evaluated by comparing the results of the simulator with the results of the model calculations.

This paper describes several trials performed CHIBA test track 2 in the university of tokyo. These trials including a low-speed wheel climbing test using test trolley, expansion of facilities on CHIBA test track 2, coloring of track and bogie with water-based rust prevention and improved visibility, suppression of track temperature rise, Visualization of the contact position between wheel and rail, suppression of squeak noise, trials of non-contact speedometers, and data collection for detecting obstacles in the running space.

This paper introduces the data acquisition efforts of abnormal condition data including wheel climbing on the Test Track, and the approach to data analysis. This is part of research on derailment sign detection for railway vehicles.