A compliance matrix, which expresses the relation between bearing deformation and oil film pressure, is used in an elasto-hydrodynamic lubrication, EHL. The compliance matrix is derived with a structural analysis of a con-rod using design data of a 3D-CAD. Force distributions on the boundary of the con-rod are obtained from the oil film pressure on the bearing surface calculated with the EHL. Stress analysis is performed using the structural analysis in the 3D-CAD and the stress distributions in the con-rod are clarified over an engine cycle. The results under low and high engine speeds are shown in comparison with each other. Finally, the effect of engine speed on the stress distribution and the maximum stress is discussed.

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Understanding of piston skirt friction is important for reducing piston friction in internal combustion engines. For this purpose, the oil film distribution on the piston skirt is visualized and observed in a gasoline engine with a transparent sapphire cylinder. In this study, friction calculations are carried out for the striated oil film area of skirt. It is supposed that the area has a Couette flow by analyzing oil film images. It is found that the friction of the striated oil film area is around 3.5 to 9.9% of the friction of whole skirt.

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Increased pressure, which has been strongly desired for diesel fuel injection equipment, has many technological challenges. One of the biggest ones is the increase in temperature caused by leakage fuel. The investigation of constant leakage from sliding portions inside injectors reveals that the deformed structure due to the increased pressure substantially affects leakage quantity. It also indicates that the leakage quantity which is in proportion to pressure by the base equation, is not, and takes higher degree than 1. Based on the results, the estimated leakage quantity has approximately threefold increase when pressure increases from 200 MPa to 300 MPa.

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Interactions of gas parcels with different histories of composition, temperature and reaction during the mixture formation in spray combustion may either enhance or inhibit the ignition depending on the cases. In this study, the impact of the history of low-temperature oxidation has been investigated by using zero-dimensional kinetic simulations with a multistage adiabatic mixing model developed to mimic the pilot injection and dual-fuel combustion. The results can be well interpreted in terms of the evolution of chain carrier species in the low-temperature oxidation and the occurrence of cool flames with the formation of the inhibitive intermediate such as formaldehyde.

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Two dimensional (2D) temperature and concentration distribution plays an important role for the combustion structure and the combustor efficiency in engines, burners, gas turbines and so on. In high temperature and pressure fields such as engines, the non-contact 2D temperature distribution cannot be attained by thermocouples, which are intrinsically a point measurement method. In this study, the experimental research has been conducted in order to develop the non-contact and fast response 2D temperature and concentration distribution measurement method in high pressure and high temperature fields using CT-tunable diode laser absorption spectroscopy (TDLAS).

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Extinction characteristics of both diffusion and premixed hydrocarbon (CH₄, C₃H₈, and DME) flames at elevated pressures were studied using counter flow configuration. Experiments were conducted under N₂ dilution and CO₂ dilution conditions. For all fuels, flames were found to become hard to be extinguished either with increasing pressure or using CO₂ dilution in place of N₂ dilution with keeping the same adiabatic flame temperature. The effect of pressure on extinction characteristics was quantitatively discussed in terms of Damkohler number using numerical simulation. In addition, the difference in extinction characteristics between N₂ dilution and CO₂ dilution was investigated in terms of Lewis number effect.

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Diesel oxidation catalyst (DOC) stores unburned hydrocarbons at low temperatures, such as during long-term idle operation, and then releases them rapidly at high temperatures during acceleration. The high level of unburned hydrocarbons result in visible white smoke emission at tailpipe. The purpose of this work is to get a better understanding of the phenomenon of white smoke emission originated from HC accumulation on DOC. Firstly, the component and size distribution of the HC white smoke has been analyzed. It was clarified that semi-volatile organic compounds and water are condensed around SOF component (e.g. C17~C24 heavy hydrocarbons in fuel), leading to a submicron-sized particulate emission. Furthermore, the effect of distillation characteristic and molecular structure of the HC accumulated on DOC has been examined. The experimental results show that the amount of adsorbed HC is strongly influenced by the 50% distillation temperature and also that aromatic hydrocarbons tend to increase white smoke emission compared with paraffinic hydrocarbons.

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This study analyzes the factors influencing the thermal efficiency of HCCI combustion in an over-expansion cycle engine. There are many influencing factors when combining the over-expansion cycle and HCCI combustion since 80 experimental conditions were included when varying compression ratio, expansion ratio, intake air temperature and equivalence ratio. The combustion efficiency is shown to be one of the dominant factors. Since the correlation coefficient between the combustion efficiency and ISFC_g was -0.90. The over-expansion cycle is also shown to be effective to improve the thermal efficiency. The late-closing of intake valves contributes to extending the operating range of HCCI combustion.

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The characteristics of knocking performance under turbocharged conditions were studied. To clarify the mechanism from the viewpoint of auto ignition processes of fuel/air mixtures, fuels with independently different Research Octane Number (RON), Motor Octane Number (MON), and ethanol content were prepared. The knocking performance of these fuels, under both natural aspirated and turbocharged condition, were experimentally evaluated in a single cylinder research engine. Results show that contributions of RON and MON to knocking performance changes with engine operating conditions. For further analysis, elementary reaction calculations with reaction schemes which can simulate given RON and MON properties were performed. The mechanism was explained with characteristics of low temperature oxidation with each fuel.

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The development of the material for pinion shaft in planetary gear set was performed to solve the durability problem of downsized auto-transmission. Resistance to softening of pinion shaft in hot environment was increased by adding Si and resistance to crack initiation due to dent was increased by adding Mn. As a result of this study, thrust rolling contact fatigue specimen with developed material showed increasing fatigue life and there was no flaking on the surface of pinion shaft after transmission durability test.

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Idling stop system and charging control system have been established widely as an efficient measure to improve fuel efficiency for conventional powertrain vehicles. The effect of charging control system is higher at lower SOC (State Of Charge) of the lead acid battery. However, if Idling stop system works at the same time, SOC becomes lower level and makes it difficult to maintain two functions. The purpose of this study is to satisfy both functions by appropriate SOC control based on driving environment and to improve fuel efficiency.

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This paper mainly focuses on the internal resistance sensing technology that has been newly developed for an automotive fuel cell system. Precise feedback control of water balance inside fuel cell stack contributes to cost reduction of fuel cell system by system simplification. To achieve this, the stack internal resistance measurement technique using Impedance Bridge has developed to detect the water content of a MEA precisely. And that sensing prototype circuit was verified to meet the requirements of a water management system. By using this sensing technology realized the cost reduction of PEFC system via simplification.

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The company to which authors belong sold 650 PHVs through lease programs for the validation test in Japan, the U.S. and Europe from December 2009 to August 2013 and got the detail driving data by the data loggers which are installed on some vehicles. Influence on the environmental performance of the charging infrastructure, EV range of PHV and other factors were analyzed based on the data. This paper discusses the analysis results.

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This paper develops the method of estimation of tire model for static steering effort. In order to estimate tire force and moment during static steering, the tire model parameters used so-called Dahl friction model are identified by measurement data on actual road. Moreover static steering effort is calculated by using the steering model, and steering effort is compared between measurement values and simulation results. The measurement values and simulation results show good correlations during static steering.

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Distraction due to thinking or reduction in arousal level make a driver difficult to notice the surrounding hazard. Therefore, it is important to notify the surrounding hazard so that the driver can recognize it so quickly. However, it has not been considered the appropriate way to notify the hazard. This study proposes warning sound localization, which allows the driver to recognize the direction of the hazard intuitively. Its superiority is revealed by following experiments: 1) While a driver performs driving task, reaction time and distraction rate were measured until the driver recognizes the hazard. It was found that localized warning sound could shorten the reaction time, and could keep concentration of the driving task. 2) Driver’s brain activity was measured by NIRS (Near-infrared spectroscopy) while the driver is notified the hazard by blinking LED or by localized warning sound. It was found that the localized warning sound could reduce the brain load than blinking LED. Thus, localized warning sound allows the driver to recognize the hazard quickly with little brain load.

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In recent years, careless driving by fall asleep is frequently because of poor concentration and loosening tension in car driving. In this study, the support of the awareness level maintenance to a driver was applied into a vehicle interior, and then audiovisual information with the effective visual stimuli and auditory stimuli for the application was studied. First, it was observed that the effective stimulus obtained by the past study shows a similar trend in awareness level maintained simply in the environment simulating the vehicle interior. Next, the effectiveness of the awareness level maintenance was compared with different ages to examine the generality. Further, the effect of the complex stimuli was verified for the purpose of application to the vehicle compartment space.

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In this study, an influence of vehicle styling impression on acceleration sound quality rating was investigated. Luxury or sporty vehicle images were presented to the participants as the acceleration sounds were being replayed. The results indicated the participants rated the acceleration sound presented with the luxury vehicle image as louder and less luxury than that with sporty vehicle image. However, they rated the sound sportier with the sporty vehicle image. Consequently, it was clarified that rating to sound quality changed depending on the vehicle styling but the tendency was different in each term for the sound quality evaluation.

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Recently, comfortable automobile running sounds are considered to be an added value to attract the attention of automobile users. This study, in order to develop an automobile running sound on which people can feel comfortable with their multiple sensations, an objective sound quality evaluation based on physiological information will be focused on. However, dispersion can occur in a measurement result because physiological information is not stable due to a difference of their internal thoughts or their physiological conditions. Therefore, the method to reduce the dispersion in the physiological evaluation result will be proposed by using the tasks that are helpful to regulate subjects’ conditions. In this paper, following three studies will be discussed; (1) consideration of the effective task to reduce the dispersion by objective evaluation, (2) construction of experimental condition using the driving simulator to evaluate car running sound in conditions similar to actual vehicle ,and (3) trial of an objective evaluation of car running sounds in simulated driving condition using the task

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This paper introduces a smart phone application, which gives feedback to drivers about their braking performance using artificial vehicle information created within the smart phone. This application offers an added value that improves driving technique while having great driving experiences by making connections between various drivers. As a result of using this application, improvements in drivers' skills have been confirmed and an increase in car safety has been made.

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The purpose of this study was to establish an injury prediction algorithm for an Advanced Automatic Collision Notification (AACN) system for vulnerable road users such as the pedestrian and bicycle users. The injury prediction algorithm was based on two independent samples of ITARDA macro data, one of which was used for training and the other as for validation. The AACN algorithm was developed using the Japanese large scale accident database by a logistic regression modeling technique. The Risk factors associated with severe injury for pedestrians and cyclists were travel speed, the frontal shape of striking vehicle, pedestrian and cyclist age, type of road and pedestrian and cyclist behavior. Validation of both AACN algorithms were verified using ROC analysis. The results indicate that for a 10% rate of under triage, the threshold values are 8.8% and 2.9% for pedestrians and cyclists respectively.

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A ladder frame structure of a pickup truck absorbs most part of energy in frontal crash. The frame structure consists of thick steel plates, and to simulate buckling phenomena of the thick plates by using shell element is sometimes difficult. In this report, characteristic curves of force against displacement of the frame's parts under compression and bending load are evaluated by both shell and solid elements, and limitations of applying shell elements to simulate post-buckling phenomena such as effective width of the frame are discussed.

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This paper investigates the shared driving characteristics of a steering assistance system for obstacle avoidance maneuver as one of the functionalities of autonomous driving intelligence. It is important to study how such autonomous control function should be designed in order to obtain good driver acceptance when both human and the system act in parallel as a shared control task. This paper evaluates the shared driving characteristics when the degree of the steering assistance function is set at different levels. Using the driving simulator, elderly drivers are employed in the experiment. The obstacle avoidance performance and the handling quality of the vehicle are discussed.

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A human body finite element (FE) model including discrete internal organs and whole body muscles was developed to elucidate injury mechanisms of occupant internal organs in real-world automotive accidents. The discrete internal organ models were validated against experimental test data using porcine specimens while the whole body FE model was validated against five cadaver test data on frontal impacts. In addition, the human FE model with and without a braced condition was applied to frontal impact analysis. Simulation results suggest that occupant postures could alter according to muscle activation level and have some effects on occupant internal organ injury mechanisms.

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A simple dynamic human model in side impact crash is introduced based on finite element (FE) model. The simple dynamic model consists of three masses corresponding to the thorax, the upper body and the lower body. The thorax mass was introduced in order to consider the thoracic deflection. The thorax and the upper body were connected by a linear spring and a linear damper in parallel. Numerical simulations show that the simple dynamic model can approximate the thoracic deflection, the upper body displacement, and the lower body displacement of the human FE model in side impact crash.

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In this paper, it is investigated by focusing to stiffness balance of seat-frame as one of the measures to reduce neck injury. The balance of the seat-frame stiffness, it is thought that to reduce the motion difference between the head and torso causing neck injury. First, we will describe an idea of balance the seat-frame stiffness to reduce neck injury. Next, the experiments for carrying out the verification of the energy absorption that is considered essential to the balance of the seat-frame stiffness. Finally, we will discuss the control of motion difference between the head and torso in the experimental results and the seat frame stiffness.

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Image and vehicle data recorded by drive recorders are analyzed to clarify the difference of rear-end near-miss incidents between the low-speed (20 km/h or lower) and the high speed (40 km/h or higher) regions. The major understandings to be drawn from the analysis are as follows. There are significantly fewer relevant factors involved in the low-speed incidents than high-speed incidents. In the cases of low speed, small overlap cases account for a comparatively high percentage in the number of incidents whereas the actual accidents have different tendency. In the case of high speed, rear-end incidents after another car cuts in front of a subject car accounts for a considerably higher percentage compared with the low-speed cases.

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In-vehicle information systems become more convenient by various functions. But those systems increase driver distraction and causes careless driving. With these situations as a background, development of in-vehicle information systems that limit user operation and presentations of information by driver workload have been extensively studied. In this paper, we reported a workload estimation method for drivers that breaks down a series of driving operations into its each operation and quantifies the workload by the VACP method. Results of evaluation experiments by NASA-TLX show that the proposed method is worth to estimate driver workload.

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This paper describes the difference of injury mechanisms between THOR FE model and Human FE model. The National Highway Traffic Safety Administration plans to introduce a new test method that uses RMDB and THOR. However, injury mechanisms of THOR dummy necessary for the development of occupant protection equipments are not explained enough. The injury values and injury mechanism of THOR dummy in oblique condition were compared with the human FE model (THUMS). Mechanisms of BrIC and Acetabulum Force were investigated in relation to the horizontal movement of THOR dummy.

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In auditory signal design for vehicle on-board systems, it is possible to freely select the combinations of tone characters, harmony/chords or melodies to provide the signal with the desired function. Higher harmonics, harmony and sustaining time are discussed as the tone characteristics of information sound in this study. The sensibility/Kansei values of these factors were subjectively evaluated by 135 participants with a wide range of ages. The adjectives were classified into two stages that related to “physical property” and “sensibility/Kansei value”. The results give a clearer understanding of the relation/structure between the “physical property” of the information sound and the “sensibility/Kansei value”, and clarified guidelines for how to design tone characteristics to realize the sensibility/Kansei targets.

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Evaporative emissions from gasoline vehicles in Japan has been estimated using a real world model. This model consists of a model of permeations from fuel tank and fuel pipes, and breakthrough emissions from canister. Since user operation has an influence on breakthrough emissions, the investigation took place in three regions: metropolis, provincial cities, and rural areas. In areas with similar weather conditions, the daily maximum and minimum temperatures were adapted to the model. The estimated total amount of evaporative emissions was 34459 ton per year. Estimated results show that evaporative emissions in metropolis area is relatively high in Japan. Evaporative emissions from gasoline vehicles account for almost 4.7% of all the stationary sources in Japan; this is the fourth largest amount among all stationary sources.

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This paper deals with the friction coefficient μ variation of a disc brake system with moisture. In our previous studies, it was experimentally found that wet wear debris between the brake pad and the disc rotor affect μ variation and μ of the wet wear debris increases with decreasing their moisture content. Based on the experimental results, we propose a hypothesis that clusters composed of the wet wear debris induce μ variation when the clusters stand between friction surfaces. In this paper, for supporting the hypothesis, we tested the shear properties with different kinds of liquid, and simulated the wear debris behavior under wet condition between friction surfaces using the discrete element method. From these results, we clarified that the wet wear debris made the clusters due to the capillary force, and their behavior contributed the increase of μ.

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The specific dissolution and exfoliation of chrome plating in Russia is studied. As a result of investigation and analysis of organic compounds in Russian soil, it was found they contained high concentrations of fulvic acid. Additionally, it was found that fulvic acid, together with CaCl₂ (a snow melting agent), cause chrome plating corrosion. The fulvic acid generates a compound which prevents the reformation of the passivation film and which deteriorates the effect of sacrificial protection of nickel for corrosion.

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