Steering reaction torque changes with respect to input frequency because steering torque is under influence of vehicle dynamics. A new electronic power steering (EPS) control strategy that is the damping control with the filter is introduced to compensate for steering torque property with respect to vehicle dynamics. This simple control is easy to add on present EPS system. Both steering damping and steering response performance are improved by this control. Not only steering feeling but also roll feeling is improved, by this EPS control.

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Studies were conducted on catalyst and emission control technologies with the aim of extending lean operation of gasoline direct injection engines for better fuel economy. A 99.5 % NOx purification efficiency was obtained with a potassium-based NOx-trap catalyst by enhancement of gas diffusivity in the washcoat and also sulfur purge capability. Combined with HC reduction technologies such as a larger valve-overlapping during cold start catalyst warm-up and HC slip prevention control during NOx purge operation, a vehicle with this catalyst meets the Japanese SULEV regulation.

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A urea SCR system was combined with a DPF system to reduce NOx and PM in a 4L turbocharged with intercooler diesel engine. Urea injection control logic was developed for various low temperature and high temperature transient operations. Significant reductions in NOx were realized in JE05 and WHTC modes by adopting the urea injection control. It has been shown that NOx can be reduced by 95%, achieving the challenge target value of NOx in JE05 mode.

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The nitrogen components(NO,NO₂,N₂O and NH₃) analyzer has been developed utilizing Quantum Cascade Lase (QCL). The QCL can emit in a mid-infrared region where these nitrogen components have strong absorption. This laser optics configuration can give us a super fine resolution of the mid-infrared spectrum. Therefore, utilizing this spectrometer can reduce the interference caused by the spectral overlap of co-existing gases in engine exhaust gas. The developed analyzer has been evaluated using actual engine exhaust gas to confirm the influence from coexisting gases and the measurement accuracies and stabilities.

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This paper introduces results of the feasibility study of a lane keeping assist system utilizing the rear view camera for a parking assist system instead of a dedicated front view camera. If a rear view camera is shared, the total system cost can be significantly reduced. However, the system has some disadvantages also such as delay of lane recognition that causes degradation of the control accuracy for lane position, and detection loss of lane markers due to the low image resolution in distant area. We propose the countermeasures for these concerns, and show the simulation and experimental results.

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Improving performance and reducing the costs are the most important issues for humidifiers of fuel cell vehicles. By developing the method for analyzing the quantitative gas velocity distribution that flows outside the hollow fiber membrane, new humidifier design, called inner by-pass flow model, was developed to obtain much uniform gas velocity distribution. In comparison with the conventional counter flow model, the inner bypass flow model configuration showed the higher efficiency of overall water flux in the whole module, and reduced the pressure drop, enabling approximate 40% decrease in the size of the humidifier, which can contribute the cost reduction.

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This research deals with the influence of the breaking force to turning characteristics of two-wheeled vehicle. For the former research, the characteristics of steer and slip angle at turning are described. In this research, the influence of breaking force to steer torque are described using quasi-steady state analysis.

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A new method of slip ratio control to improve traction for all-wheel-drive vehicle utilizing vehicle acceleration together with the time derivative of the slip ratio is proposed. This control method automatically suppresses the increase of slip ratio whenever it is over the optimum, such as in case where the target slip ratio becomes higher than the optimum. The control is based on vehicle acceleration for adaptability to all-wheel-drive vehicles, where conventional wheel speed based control had difficulty when all-wheel went into a wheel spin. The new control method was implemented into an electrical-motor-assisted-all-wheel-drive vehicle and showed improved low-friction-traction performance.

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The authors focus on anti-rolling performance of a heavy vehicle, and propose to suppress the roll motion of the heavy vehicle by active control using electromagnetic suspensions. The body of the heavy vehicle is modeled as a continuous cylinder to describe torsional motion, therefore differences of roll angles of the front and the rear axis can be expressed. Then the authors design a control system to suppress the roll and torsion of the body using optimal control theory. The results of the numerical simultations and the experiments show the proposed system reduces roll angles of the torsional body better than the passive suspension system.

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This paper describes a developed simulation of vehicle thermal management and the analysis method of its result. The analysis method is able to show the total input and output of heat flow of a component in engine room and under floor in each mode of conduction, radiation and convection, and to show the detail of heat flows between a component and its surroundings in mode of conduction and radiation.

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FE models for pedestrian dummy and human knee joints were subjected to 4-point bending simulations in valgus bending. Failure threshold for each ligament of the dummy was estimated from the correlation between the dummy and human models. The maximum tensile force for each ligament of the dummy obtained from full-scale impact simulations using a full-body dummy FE model and vehicle FE models with different front shapes was normalized by the threshold. The results were compared with the distribution of observed injuries from published full-scale car-pedestrian impact experiments using human subjects and similar cars to validate the estimated thresholds.

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We investigated the effectiveness of seatbelt and airbag on high-energy traffic accident with frontal impact. The severity of head and neck, chest, abdomen and extremity were significantly lower in belted patients than un-belted patients. The severity of head and neck, face were significantly lower in airbag-deployed patients than un-deployed patients with seatbelt use. On the other hand, the severity of chest and abdomen were significantly higher in airbag-deployed patients than un-deployed patients in unbelted patients, which must be alerted to all car users.

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Recently, one of the most important appeal points of a wagon type vehicle is the spaciousness of the rear seat with the long slide adjuster. But if the sheet position of the vehicle is changed, there is a possibility of influencing the occupant injury. Therefore, the quality engineering was applied to vehicle collision tests using scale models and the safety performance of the rear seat occupant was examined. As a result, it was confirmed that the change for the relative position between the shoulder belt anchor position and the occupant greatly influenced the occupant restraint.

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In connection with lowering birthrate and logevity, the ratio of traffic accidents in which elderly people are involved is increasing, and the need for elderly injury mitigation is also increasing. In this study, human FE models capable of evaluating lumbar spine injuries for adult and the elderly were developed incorporating the changes of the material characteristics and bone geometry of the lumbar spine due to aging investigated and quantified from the literature. The models were validated against the test results for corresponding age groups from the literature.

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Human thorax FE models for evaluating thoracic skeletal injuries both on adult and the elderly were developed. The rib cage geometries were generated based on the medical CT images and the literature. The material properties of the rib, costal cartilage and clavicle were estimated based on the literature, and for the sternum, the material property of the rib was used. The models were validated against isolated bone bending and chest impact tests from the literature.

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There are two kinds of infrared images of a night driving assistance system, which are provided to drivers in order to inform the less-visible pedestrian; a NIR (Near Infrared) image and a FIR (Far Infrared) image. In the present paper, drivinig simulator experiments with a pseudo infrared image are performed under the various external temperature and brightness conditions to verify the influence of the difference of the infrared image on avoidance actions to moving pedestrians.

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Hydrocarbon mass emitted, while cold start, becomes significant as vehicle emission restraints tighten. This paper investigates the mechanism of emitted hydrocarbon reduction as forwarding the exhaust valve close timing at the very beginning of cold start, because there are relation between in-cylinder wet and emitted hydrocarbon. The hydrocarbon reduction was due to the backflow of the operating gas into the intake port, boosting the fuel vaporization. Emitted hydrocarbon at engine start is 30% decreased in consequence.

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This study was aimed at clarifying the effect of lower tension pisotn rings on piston friction and lubricating oil consumption(LOC). Floating liner method and sulfur tracer method were applied simultaneously to measure the piston fiction and LOC with gasoline engine. This paper described how each ring tension acts on both piston frictio nand LOC. In order to verify the reasons, oil film behavior around the piston and rings were observed by the engine with optical glass window.

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In order to reduce exhaust emissions and increase the brake thermal efficiency in a direct injection (DI) diesel engine, we pursued the combustion chamber and the fuel injection characteristics under the common rail fuel injection system and the high compression ratio. As a result, we could find the combustion chamber improving NOx, smoke emission and the brake thermal efficiency. And the relations between the combustion chamber and the fuel injection characteristics, gas flow and combustion characteristics were clarified.

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Alminum alloy has been gradually adpoted for engines components for reduction fo its weight. A bearing housing mode of Aluminum alloy tends to reduce interference between the nousing and bearing under the operating condition due to higher coefficient of linear thermal expansion of Aluminum alloy. Less bearing/housing interference tends to cause bearing creep, and the creep causes damage to the bearing race. The mechanism of the race damage was investigated in this study. The bearing creep speed, retainer rotation speed and inner race temperature were measured, and theoretical retainer speed was calculated using measured bearing creep speed. It was found that larger creep speed caused larger deviation of measured retainere speeds from calculations. According to increase of the deviation, the inner race temperature, however, decreased at first, and turned to incerase at acertain point. This temperature trend could be explained by the ball/race skidding retio considering differential skidding and the deviation. Finally, the effect of temperature rise of the race cuased by creep was investigated by the durability test. Findings showed that temperature rise caused the damage to the bearing race.

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The operating range in premixed diesel combustion is limited by rapid combustion at maximum loads and unstable ignition at minimum loads, both affected by ignition delays and ignition timings depending on fuel ignitability. To analyze the correlation between ignition delays and common fuel ignitability factors represented by cetane number or octane number, fuels with various ignitability factors were examined at an early injection timing (30°CA BTDC) and a low intake oxygen content. The ignitability factors correlated moderately with ignition delays, with notable irregular fluctuations. The operating range in premixed diesel combustion depended most strongly on the actual ignition delay.

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NOx reduction mechanism and a requirement for high NOx reduction efficiency in a urea SCR system at transient conditions with low exhaust gas temperature were investigated by using a four liters multi-cylinder diesel engine. NOx can be significantly reduced by adjusting mode-overall SCR inlet NO₂/NOx ratio at 0.5±0.1 with adopting NH₃ adsorption quantity control. It has been shown that ammonium nitrate (NH₄NO₃) plays an important role to proceeding Fast SCR reaction at transient low exhaust gas temperature conditions.

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Minimum oil film thickness is one of the most important issues for optimization of a bearing design. We developed a technique to measure an oil film thickness by the change in capacitance between the shaft and a thin-film electrode of several micrometers thickness formed on the surface of a bearing. Measured oil film thickness with thin film electrode corresponded to the calculated value with the elasto-hydrodynamic lubrication theory. The Authors applied this technique to the main journals of a nautomobile engine and measured their oil film thickness up to maximum speed and full load. The oil film thickness became thinner with the increase of engine load, and became turned thick with the increase of engine speed. Furthermore, we measured an oil film thickness by the total capacitance method, the conventional method, and compared the two values.

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The chemical fundamentals of HCCI combustion processes are investigated and discussed in this paper. There are two reaction routes depending on the types of hydrocarbons. N-paraffins are easily decomposed into radicals and low molecular hydrocarbons during LTHR, and those chemicals assist the start of HTHR reaction (Route 1). On the contrary, naphthenes and aromatics are mostly stable during cool flame period and ring opening reaction temperatures are different(Route 2). Those two reaction routes give the HTHR personalities of hydrocarbons in HCCI combustion.

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It was reported that n-heptane and toluene blended fuels(NTL series fuels) showed the dual phase high temperature heat release (DP-HTHR) combustion in a previous paper[1]. DP-HTHR has the potential to enlarge the engine operational range to high load conditions. Further research has been reported in this paper. Initial interests were in the combustion characteristics of a second "bump" in the high temperature heat release in DP-HTHR, since this kind of two-stage combustion appears, when CO oxidation occurs radically. The second interest was the possbility of DP-HTHR combustion with the blends of the refinery based gasolines. Those two topics were fully investigated from the point of combustion and emission data in this paper.

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Advanced engine technologies, such as variable velve actuation, ultra-high pressure fuel injection, and high pressure turbocharger, have been developed for reduction in emission and fuel consumption of diesel engines. Objectives of this study are to investigate possibility of a new clean combustion with advanced engine technologies, and to clarify effects of fuel properties on the advanced engine combustion. The result from this study represents that decreases in fuel ignitability and T90 derive a long premixing period or promotion of fuel evaporation that could reduce soot emission. And it is clarified that simultaneous use of ultra-high pressure fuel injeciton and high pressure turbo-charging could expand operation limit with ultra-low emission and silent diesel combustion.

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We propose a new method for evaluating the amount of adhesion fuel when fuel spray impinges on the wall surface by considering the normal and tangential droplet impact velocities. To verify this method, we examine how the amount of fuel adhered to a flat plate varies with the spray's angle of incidence. Our experimental results show that less fuel adheres to the wall when spray is oriented obliquely. To verify our method, we also examine the concentration of the air-fuel mixture and the fuel film thickness formed in an engine intake port model when a fuel spray is injected. By comparing these experimental results with our calculated results, we show that our proposed method can evaluate the behavior of adhered fuel which conventional methods can not evaluate.

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We have performed the chemical kinetic simulations for multi-fuel HCCI combustion with alkane, alcohol and ether. Sub fuels were added at premixed conditions and after low temperature oxidation. From the analysis using contribution matrix, the ingition delay times of neat and multi-fuel depend on heat release by H₂O₂ Loop. For alcohol oxidation, the reaction of HO₂ with fuel inhibits the heat release by H₂O₂ loop. The mixing effects of fuels appear in the H₂O₂ and CH₂O concentrations those related to heat release by H₂O₂ Loop and the concentrations of these species are mainly from lower octane number fuel. Thus the larger variation of ignition delay times can be attained with premixed mixtures between higer octane number main fuel and lower octane number sub fuel.

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Hydro-carbon thermal ignition processes were analyzed by using the tools developed by the authors, "Contribution Matrix" and "Atomic Balance". It was proposed to explain the thermal ignition process from four view points, H₂O₂ Chemistry, HO₂ Chemistry, H₂-O₂ System Chemistry and CO₂ Chemistry. In case of the pure Hydrogen-Oxygen system, Reaction of (R12) OH+H₂→H₂O+H plays a significant role. In case of Hydrocarbon thermal ignition, however, contribution of this reaction is not important because of the lower H₂ concentration. (R13) CO+OH→CO₂+H plays a predominant role in place of (R12). The only path to generate CO₂ is this reaction. In the H₂O₂ Chemistry dominant regime, (R12) convert CO slowly into CO₂. The mafor portion of CO₂ is generated by the same reaction during the final stage of the H₂-O₂ System Chemistry.

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We propose the control/circuit simulation system using motor model with magnetid saturation characterisitcs and harmonics created by electromagnetic filed simulator. That motor model has the inductance, magnetic flux and torque information of each motor which include the spatial harmonic components and effect by magnetic saturation. And we made the Interior Permanent Magnet Synchronous Motor(IPMSM) for estimation of that motor model and compared current, voltage, iron loss results given by the simulation with the experimented values.

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Driver assistance for cognition and judgment is effective for reducing traffic accidents. However, environment recognition by the sensor is not perfect in the real world. False and missing alarms may cause dangerous situations or disuse of the system by losing driver's trust. We propose a warning method corresponding to recognition reliability of the sensor to suppress reduction of trust from the standpoint of risk engineering. In this research, evaluation experiments using a driving simulator were conducted for a lane change decision aide system. Effectiveness of the proposed warning method was verified when using the sensor with some errors.

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This paper proposes a pedestrian collision avoidance system based on a monocular camera and a millimeter wave radar, as one of the active safety technologies to protect pedestrians. The method to decide about the presence of a pedestrian is based on the assumption that objects moving along a crosswalk can be interpreted as pedestrians under certain circumstances. The camera can be used to detect the crosswalk. Data from both sensors can then be used to infer abut the presence of a pedestrian. The sensor fusion algorithm which combines data from the sensors is explained. Then the paper describes a warning concept which provides visual information about the presence of a pedestrian to the driver, depending on an estimated probability for a collision. Finally, results from test drives on an experimental vehicle with the system running in practice is presented.

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The effect of improved visibility at night by the adoption of the Adaptive Front-lighting System is promising. However, in order to confirm whether or not the AFS is really beneficial for drivers. It is necessary to perform an evaluation of performance by considering the vehicle as a man-machine that is integrated with human characteristics. Therefore, the effect of the AFS was confirmed in the present research by performing experiments in which a fixed driving simulator is used and actual vehicle experiments with the objective of quantifying influences on the driver's perception, judgment, and operation characteristics by AFS.

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Increasing number of traffic accident in stopping at intersection caused by the aged drivers has become one of the traffic accident characteristics. This paper aims to propose an information assistance system for elderly drivers who show the unsafe behavior in stopping at intersection. The goal of this research is mainly to clarify a strategy for designing the information assistance method by analyzing the perception and recognition performance of each driver during driving. Finally, this paper demonstrates the effectiveness on enhancing the safe behavior in stopping at intersection by using driving simulator and real vehicle.

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Advanced diesel engine emits reduced unregulated emissions, but there are few reports on transient emission behavior of the unregulated emissions. This report shows that a time-of-flight mass spectrometer combined with ionization by proton transfer reaction has higher time (as short as seconds) and mass resolution, and its higher sensitivity as low as several ppb was evaluated. The mass spectrometer was applied to measurements of emission from diesel engine to verify effects of DPF.

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In the study, a multidimensional scale for defensive-driving assessment was developed based on the driving instructors' knowledge. Firstly, totally 272 assessment items were collected through interviewing with instructors and reviewing conventional scales assessing drivers' characteristics, and 38 items were nominated as the candidates of the new scale. Secondary, instructors tried to assess 469 drivers' driving with these items. As results, 4 assessment factors were abstracted through the factor analyses, and the Defensive-Driving Assessment Questionnaire (DDAQ) was constructed with 15 significant items. Finally, a statistical model of defensive-driving assessment was proposed and verified using the structural equation modeling.

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We conducted a queationnaire survey in order to clarify how the interface design of the automobile influences the user experiences at ear seats. Survey was conducted on different types of interface, and factor analysis was used in order to identify factors that explain the questionnaire results. Consequently two factors such as 'usability' and the 'pleasantness' are revealed. It is also observed that those factors tend to be incompatible. Further studies will be required to examine whether they can be compatible.

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Micro air vehicle(MAV) has marked potentials for aerial surveillance becuase of its low cost of operation, high portability, and low risk of injury by crash over residential aea. MAV, however, has an inevitable limit of performance owing to the insufficient payload and susceptibility to aerial disturbances. The application of collective motion control to multiple MAVs is proposed here to solve this problem, integrating individuals' performances to realize high capability and reliability for various missions. Biologically inspired collective motion control is incorporated here and the simulation results clarifies its ability to realize various collective motions, e.g. loitering or shape control, by using simple interaction parameters, as well as the robustness to the change of MAV numbers in operation.

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Automotive software is rapidly increasing the size and complexity due to the high demand to the advanced functions of safety, fuel-economy, and emission control. This article proposes a SOA (Service-Oriented Architecture) for the automotive embedded software, an emerging paradigm to automotive software development. We propose a model of SOA for the automotive software, which enables the integrated control of distributed software across ECUs as well as control between vehicles and service providers over the communication networks. We discuss the effectiveness of the proposed architecture with the evaluation of various aspects of the architecture.

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