An analytical method was developed to compare the effects of vertical spring of suspension, dumping force, height of the center of gravity, roll-center height, roll steer, and initial toe angle to the easiness to change direction, by introducing the lateral displacement of the tire contact point relative to the center of gravity according to the roll movement, into the dynamic equation that was reported in the previous paper. This paper introduces the analytical method and presents samples of the effects of those factors to the easiness to change direction.

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In a pedestrian accident, the loading direction to the pedestrian thorax is affected by the posture of the pedestrian upon impact and a subsequent rotation of the upper body. In order to evaluate thoracic fractures due to loadings in different directions using a pedestrian dummy, as opposed to existing criteria for one single loading direction (frontal or lateral), this study investigated a technique for two-dimensional evaluation of thoracic deflection using human and dummy FE models and formulated injury probability functions for thorax of a pedestrian dummy.

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To pursue the possibility of engine thermal efficiency improvement, the effect of individual setting for compression and expansion ratio was investigated. Huge improvement of the thermal efficiency was confirmed with super high expansion ratio (20 or more) under the restriction such as self-ignition to be caused by a high compression ratio, through the theoretical calculation. The efficiency improvement of 10%or more was confirmed with the actual experiment using four cylinder compact engine.Moreover, from the analysis of efficiency improvement along with the engine load change, it is revealed that high thermal efficiency area is extended to low load, with utilizing variable mechanisms of compression ratio and intake valve closing timing.

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In this paper, the effects of cylinder temperature and oil film thickness distribution around cylinder on the evaporated oil from the cylinder were examined by using the developed oil evaporation model in consideration with cylinder bore deformation. Moreover, the calculated evaporative oil was compared with the measured oil consumption of a gasoline engine. The results showed that the calculated oil evaporation from the cylinder wall closely corresponded to the measured oil consumption. The majority of measured oil consumption is the oil evaporated from the cylinder wall.

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A two-zone engine combustion model has been developed to determine engine design and operating parameters enabling to improve thermal efficiency by avoiding the occurrence of knock. This model is combined with modified Shell′s knock prediction scheme for unburned zone reactions as well as with a heat loss model predicting the combustion chamber surface temperature. Simulation results indicate that Exhaust gas recirculation is very effective to improve thermal efficiency avoiding knock at high compression ratios or advanced ignition timings.

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Model based control is an important technology to optimize engine operating conditions for improvements in thermal efficiency and emissions simultaneously. Modeling of intake system that includes an intake throttle valve, an EGR valve and a variable geometry turbocharger was constructed based on conservation laws combined with maps. Calculated results were examined the predictive accuracy of fresh charge mass flow, EGR ratio and boost pressure.

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A premixed type diesel combustion was developed, which achieves significant low emissions and low fuel consumptions. Its features examined by CFD withφ–T analysis and engine experiment are as follows: On φ–T map, combustion gas should use low temperature side (T<2000K) from the NOx formation area. Although the gas may slightly enter the soot formation area, it should frequently reach the ideal area (1500K<T<2000K,φ<1) where the oxidation of soot and CO•HC can be expected at the combustion latter term. The gas behavior can be realized by the extremely cooled intake gas and the reduced intake oxygen density.

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A premixed type diesel combustion was developed, which achieves significant low emissions and low fuel consumptions. The issues for its practical use were settled as follows: The control requirements of intake oxygen density and intake gas temperature are clarified. A low-pressure-loop and high-pressure-loop combined EGR system to realize the control requirements are constructed. Combustion mode switching control between the premixed and conventional type combustion without deterioration of emissions and combustion noise are constructed. Finally in the vehicle test that had installed this system, the emissions performance was examined to meet the Japan Post-New-Long-Term regulation, where the fuel consumptions improved considerably.

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Better indicated thermal efficiency by high expansion ratio on the premise of variable valve actuation using and optimization of fuel injection timing was demonstrated on single cylinder engine testing. From the standpoints of this result, further improvement of indicated thermal efficiency of a diesel engine requires high expansion ratio and high degree of constant volume with reduction of in-cylinder heat loss.

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BDF has high viscosity and poor volatility. In this study, it aims at the reformulation of physical properties of BDF by mixing with ethanol. In this paper, it describes that the effect of ethanol mixture to BDF on combustion and exhaust characteristics. The ignition characteristics, soot temperature and soot concentration were evaluated to conduct chemiluminescence photography and two color method in the constant volume combustion vessel. The exhaust emissions are measured with a stationary engine. The experimental results show that the ignition timing can be controlled and the formation of smoke and NOx can be reduced simultaneously by mixing ethanol.

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It is important for downsizing of double-cavity toroidal CVT to equalize the amount of torque transmission of four power rollers as mid-rolling element. For equalization, the structure that supports power rollers using hydraulic pistons has been applied. However, inappropriate design of trunnions and link mechanism supporting rollers and pistons brings relative displacement, resulting in interference force. The force makes differences of transmission torque among power rollers, which leads to reduction of total transmission torque. This paper presents the causes and solutions for interference between the link mechanism and trunnions and experimental results of a 20 percent reduction of interference force.

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A new ignition-combustion concept named PCC (Plume Combustion Concept), which ignites rich mixture plume right after injection of hydrogen is finished, is proposed by the authors in order to reduce NOx emissions without offering any tradeoffs on decreasing output power and thermal efficiency. In this study fundamental requirements of hydrogen jet to optimize PCC are investigated by using single hydrogen jet. As a result it was clarified that reducing jet penetration to piston bowl, reducing hydrogen wetting to cylinder head wall and igniting in the middle of mixture plume are effective to minimize NOx emissions and maximize thermal efficiency.

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Formaldehyde, carbon monoxide and hydrogen are the typical intermediates during blue flame period in low-temperature ignition of hydrocarbons. A mixture composed of only these three components and oxidizer air was compressed up to a blue-flame-dominant temperature regime using a premixed compression-ignition engine, and a two-stage ignition behavior was observed. Chemiluminescence spectra during the induction period of CO/HCHO/Air ignitions were detected in low-temperature flames. The formaldehyde was consumed much earlier than H₂ and CO; which would not be oxidized until the phase that the formaldehyde concentration becomes very low. Ignition delays are very sensitive to the presence of formaldehyde even though the amount was small. The final heat release could be recognized as a carbon monoxide explosion.

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The present paper discusses the reduction ratio of the transmission in order to minimize the energy dissipated in an electric vehicle. The motion of equation is represented by using the parameters of inverter, motor, transmission and body. The dissipated energy due to electrical and mechanical power losses is totalized. The velocity function is assumed to be linear for simplicity since the optimal one can not be obtained analytically. By using the linear velocity function, the optimal reduction ratio minimizing the total dissipated energy can be determined analytically by solving a quartic equation. The proposed method is applied to the design of optimal reduction ratio when an electric vehicle is driven with the 10 modes pattern.

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Previously several methods were proposed to reduce the stress concentration through improving bolts and nuts profile. Among those methods, (1)Tapering thread bolt (CD bolt) were proposed for stress reduction and (2) Special nuts were designed to have slightly different pitches. In this paper, a kind of nut is designed with providing slightly different pitches between the CD bolt and nut, so that the prevailing torque is appearing in order to obtain the anti-loosening and stress reduction effects. It is found that the maximum static stress concentration can be decreased by 28.6 %, and the maximum stress amplitude can be decreased by 23.9 % compared with the cases of standard bolts and nuts.

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Discharging the hydrogen gas filled in the high pressurized hydrogen container onboard causes hydrogen adiabatic expansion to change the temperature of the container, components and devices installed in the discharge line.In this study, changes in temperature of container and components were measured during the discharge of hydrogen gas from initial pressure of 70MPa.The results are as follows: 1) The temperature drop of inside of container, boss of container and pressure regulator were -43C, -27C and -24C respectively when hydrogen gas was discharged from 70MPa with a flow rate of 200NL/min. 2) At the beginning of discharge, the rapid increase in hydrogen gas temperature about +20C was observed and then the temperature dropped.

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This paper investigated the impact of deregulating the presence of stop signs prior to entering railway crossings on driver behavior at the onset of warnings of the railway crossings. When the warning of the railway crossing was presented to drivers, we evaluated the drivers′ cognition about the current situation, their decision making about “pass through” or “stop before” the railway crossing, and their actual behavior. Driving simulator experiments were conducted, and the driving behaviors were assessed based on the driving speeds and the presentation timings of the warning. In addition, the driving behaviors at the beginning of the warning were compared with the behaviors when a traffic light turned to yellow at an intersection. The results suggested that, in an optional zone where the drivers could both pass through and stop before the railway crossing, they stopped inside the intersection with the traffic light more frequently compared to the railway crossing due to their longer reaction time, and they made decision of “pass through” the railway crossing more frequently compared to the intersection with the traffic light.

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Previous study based on simulator experiments reported that a night vision enhancement system (NVES) with an accurate pedestrian warning was effective for pedestrian avoidance and it might produce a risk compensation behavior such as increasing the vehicle velocity. Therefore, in the present study, the driving simulator experiments were performed to compare the driving behaviors when using two types of NVESs with the different pedestrian detection rates.

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This paper aims at analyzing vehicle-platooning safety on a real-world arterial corridor where the initial speed and relative distance between each vehicle in the platoon were recorded via videocamera. Assuming emergency deceleration of the lead vehicle, seven-vehicle simulations were then executed to analyze variations to car-following safety within the platoon. Numerical analysis showed that platoons consisting only of passenger cars experience danger levels that are significantly higher than other platoon types. Furthermore, it was learned that a passenger car traveling just behind a heavy vehicle experiences a serious danger, even though the heavy vehicle traveling ahead of it is very safe.

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This paper investigates effects of environmental factors and driver distraction on eye-fixation-related potentials (EFRP) while driving. Various experimental conditions such as brightness and traffic condition were set up as the environmental factors in a motion-based driving simulator, and moreover several cognitive tasks were given to the participants while driving. Based on the obtained results, the relationship between EFRP, driver distraction and environmental factors was discussed.

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We surveyed needs of elderly drivers by a questionnaire. The questions were “How do you feel you become elderly especially in driving?”, “Which scenes do you feel stress during driving?”, “Which driving assistance system do you need?”, and so on. From the results, it was revealed elderly drivers were conscious of visual depression, they felt stress in night driving, and they selected the night vision system as a key assistance. So we made elderly and non-elderly drivers experience one of the existing night vision system to obtain feedback. Despite non-elderly drivers assessing the device helpful, elderly drivers assessing it unhelpful. Elderly drivers couldn't use it because of their physical depression, especially in visual functions. Therefore, we examined the new night vision system that is adapted for characteristics of elderly drivers.

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The purpose of this work is to study the influence on Eye-Fixation Related Potential (EFRP) by driver′s distraction and driving situation. The experiment with driving simulator was conducted, in which subjects were assigned both of driving task and cognitive task concurrently, while measuring their electroencephalogram (EEG) signals. The results show that the amplitude of lambda response in EFRP decreases according to the decline of attention for driving task. Furthermore, when driving in a complicated situation such as crowded intersections, there is a remarkable difference in the lambda response amplitude between concentrating and distracting state, compared with a simple driving situation.

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This paper describes the way we assure computation trustworthiness for prediction of safety system benefit based on Advanced Safety System and Traffic REaltime Evaluation Tool (ASSTREET). The way features connection between ASTREET and a driving simulator. Using it, we can find new problems to be corrected which we never assumed before driving. Furthermore, this paper compares a prediction result of traffic characteristics with its measured result on an actual street, correcting it. During this process, new problem to be corrected was discovered. The more times we repeat these processes, the better computation trustworthiness for prediction of safety system benefit.

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The present study is the first trial in which load path U* analysis has been applied to a motorcycle. Since an aluminum die cast frame cannot be regarded as a thin-walled structure, three-dimensional elements are used for FEM calculation. This is the first time that U*analysis of a FE model with three-dimensional elements has been attempted. From the results of U* analysis, we can see the bolted engine shows effective load transfer. A removed bolt changes the load transfer rate between the upper and lower frames, verifying the sensibility test result by a test driver.

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During the development of our new generation horizontally opposed gasoline engine, we used CFD and single cylinder engine to investigate the combustion process when considering basic engine specifications such as bore, stroke and combustion chamber shape. The results were a long stroke and a new design combustion chamber that maintain tumble motion to near TDC and improves flame propagation. The combination of the improved combustion chamber design together with dual AVCS, TGV and EGR cooler afford this new engine global environmental regulation adaptability.

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For efficiency improvement of automatic transmissions, very small cage and roller bearing for planetary gears, with 1.5mm diameter rollers and a 7mm diameter planetary shaft, was developed using high-strength M-shaped welded cage. As a result of needle roller shape optimization and adoption of nitrocarburized high-strength chrome molybdenum steel cage, upper speed limit reached to 1.5 times of that of conventional products.

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A development project for a hydrogen internal combustion engine (ICE) system for heavy duty vehicles supporting Japanese freightage has been promoted as a candidate for use in future vehicles that meet ultra-low emission and anti-global warming targets. In the project, high-pressure hydrogen gas direct injectors were developed. And new combustion method peculiar to the hydrogen which balanced low NOx with the high output was developed. Finally, the target power and ultra-low emissions which meet the JAPAN 2009 emissions regulation by the transient emission testing mode (JE05) were confirmed in a naturally aspirated 4-cylinder hydrogen engine which applied the injectors.

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Thermographical measurement was applied to center-holed steel sheets with and without weld bead, and partial model specimens with fillet-lap welded joints under cyclic load. Temperature ranges which correspond to the cyclic load at the crack initiation regions in all kinds of specimens did not show specific changes. Average temperature increase in the center-holed specimen without bead indicated remarkable increase in a larger stress range than the fatigue limit. In the case of the center-holed specimen with weld bead and the partial model specimen, average temperature increased slightly in stress range 10MPa and 20MPa greater than the fatigue limits, respectively.

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This article proposes a design methodology for automotive embedded software system based on the Service-Oriented Architecture. We define the property as the attributes and conditions of the automotive, environment and users. We propose four property models, which enable to systematic design of automotive software architecture for collaborative control. We evaluate the effectiveness of the proposed design methodology by applying an automotive software.

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