This paper proposes robust lateral motion control of vehicle with steer-by-wire system. For the vehicle with steer-by-wire system, we design the observer to construct a lateral motion control system without a yaw rate sensor and a lateral speed sensor. The lateral motion control system considering a disturbance caused by a crosswind is constructed. In addition controllability of the proposed system is also considered. A condition for the controllability is derived from the controllability matrix. Computer simulation results are shown to confirm the effectiveness of the proposed control system.

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Vehicles equipped with in-wheel motors are being studied and developed as a type of electric vehicle. Since these motors are attached to the suspension, a large vertical suspension reaction force is generated during driving. Based on this mechanism, this paper describes the development of a method for independently controlling roll and pitch as well as yaw using driving force distribution control. It also details the theoretical calculation of a method for decoupling the dynamic motions. Finally, it describes the application of these 3D dynamic motion control methods to a test vehicle and the confirmation of the performance improvement.

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The purpose of this paper is to evaluate the effectiveness and superiority of the previously proposed velocity guidance system using accelerator pedal reaction force control in comparison with those using other HMIs such as visual and audio devices. A set of velocity guidance experiments is arranged by using Driving Simulator (DS) to verify the four kinds of guidance system via experimental results and questionnaires. The experimental results show that haptic guidance provides higher accuracy with fewer loads to the driver in velocity tracking.

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This paper discusses design of a support function to avoid a collision with a vehicle in a dead zone when the host vehicle is going to change lanes. The following three types of support functions are compared: (1) a warning type support in which an auditory alert is given to the driver to enhance situation awareness, (2) an action type support with soft protection that resists the driver doing the dangerous steering maneuver by making the steering wheel heavier, and (3) an action type support with hard protection in which the driver steering input is canceled to prevent a collision with the vehicle in the dead zone. The results of an experiment on a driving simulator showed that action type supports were effective to improve safety. In particular, the hard protection was more effective than the soft protection for collision avoidance. The results also showed that the hard protection was as acceptable as the other two systems.

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The longitudinal motion characteristics of large sized diesel trucks equipped with the electronic governor, automated mechanical transmission (AMT) and an electronic brake system (EBS) are identified through actual running test and modeled for simulation. The　modeled characteristics of engine governor, clutch and brake are given as simple equations. The shift schedule is given by vehicle/engine speed and accelerator %. The model simulates enough actual vehicle motion and indicates used gear region on the governor chart considering the application to the fuel consumption model.

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The Helmholtz resonator not only reduces exhaust noise in resonance frequency, but also increases in other frequencies. The silencer property can control the damping in the neck of the Helmholtz resonator. In order to obtain the damping, the neck diameter must be small. Because the particle velocity is high at the neck due to the high-pressure fluctuation in the exhaust system, the pressure drop is high at the narrow pipe. When a Helmholtz resonator is designed, it is advised to control the damping at the neck diameter and the frequency at the neck length.

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In this paper a new evaluation for fluctuating aerodynamic noise under on-road turbulent flow conditions is proposed. Degree of modulation is used to evaluate the feeling of fluctuation. Furthermore, degree of modulation is applied to the evaluation index for fluctuating aerodynamic noise as Nm index. Nm index is a synthesis of Loudness (N) for the noise level and slope of degree of modulation (m) for the feeling of fluctuation. It is shown Nm index value agrees with human feeling scores relative to conventional index values.

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The electric active suspension system, named eActive3, is equipped with three electric rotary type actuators. This system can control three modes of the vehicle. Authors propose two logics of preview control in the rear suspensions. One of the logics is feed-forward skyhook control by the estimated road displacement of the single suspension. The other is feed-forward skyhook control by the estimated laterality and antero-posterior gradient of the road surface. In addition, the test result of ride comfort performance and consumption energy is experimentally verified.

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Vehicle acceleration has a large effect on occupant kinematic behavior and injury risks. In this research, an optimization of vehicle crash pulse was examined to reduce injury measures of rear seat occupants from mathematical simulation. In the optimization, the vehicle crash pulse was improved with the objective function of occupant chest acceleration or deflection. The optimized crash pulse was high acceleration in initial phase, small in the middle phase and high in the final phase. The optimized crash pulse in the final phase was higher in the case of chest acceleration than that of chest deflection due to inertial force of head and upper extremities.

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In the past research, a pedestrian pelvis injury index was examined using a human FE model and simplified vehicle models representing various shapes and stiffness characteristics of vehicles. In this research, an enhanced pelvis injury index was developed by using an improved version of the pelvis model, and further investigating the shapes and stiffness characteristics of the simplified vehicle models to better represent pedestrian loading from actual vehicles.

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A large part of pelvis injuries in pedestrian accidents are due to contact with the high bonnet leading edge (BLE) of vehicles such as SUVs. This research examined a capability of pelvis injury evaluation by comparing injuries estimated using a combination of a human FE model and a pelvis injury index, and the injury measures from the upper legform adopted by Euro NCAP for the BLE tests.

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The purpose of this study is to clarify the influential factors in frontal collision using Japanese accident data. The injury prediction method and influential factors are proposed using ordinal logistic regression model. In this analysis, the significant factors are delta-V, seat belt use, vehicle damage grade and occupant's age. The prediction model using these factors can correspond to real accident data. On the other hand, the accident conditions which do not correspond to this model have several characteristics. These accident cases are frontal pole collision, short statured elderly female, etc. There is a possibility that these characteristics are the influential factors for injury level.

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In this paper, thoracic and abdominal injury of motor vehicle occupant was analyzed in detail. In-depth accident sampling and investigation with medical and engineering network was examined. A total of 48 accidents with 58 patients injury data was collected. We analyzed the relationships between frequency distribution of thoracoabdominal injury and vehicle equivalent barrier speed (EBS), crash direction, restraint system type and use, contact components. The results show that EBS 35 km/h, frontal and nearside impact are associated with thoracoabdominal AIS 3+ injury. Lap and shoulder belt and airbag are affected with internal organs(lung, liver, mesentery, e.g.) injury and rib fracture.

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A transient engine simulation model, which consists of a zero-dimensional diesel combustion model, a one-dimensional gas flow model and an engine control model, was developed. By combining the engine control model with the previously developed engine model, it was made possible to predict the change of the combustion characteristics with the calibration of the engine control program. Application of this model to the New European Driving Cycle showed a good agreement with the measured data.

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Requirements of friendly environmental car have increased in recent years. The advancement of fuel efficiency, the clean exhaust gas, and so on by improvement of the exhaust systems are requested in the automobile industry. The flow structure inside the exhaust manifold affects the performance of the exhaust systems. The present study is carried out to understand the characteristics of the unsteady flow in an exhaust manifold under a room temperature condition. The flow is measured by a hot-wire anemometry and some laser techniques. It is confirmed that the flow direction in the exhaust manifold changed between -40deg. to 10deg. of the BTDC, because the pressure inside the cylinder at the BTDC becomes negative under the motoring engine condition.

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For reduction of NOx emission from diesel engines, it is important to capture temporal and spatial changes of NOx produced in a cylinder. However, it is difficult to observe presence of the NOx itself visually in a cylinder. Therefore, the authors quantitatively evaluated a correlation between the NOx emission and flame temperature, focusing on a relation between the NOx formation process and temperature. Consequently, the evaluation confirmed that there is a high correlation between NOx production index derived from the flame temperature measured by the two-color method using the extended Zeldovich mechanism and the NOx emission from an optical engines.

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Hybrid vehicles (HVs) are becoming more widely used. Since HVs supplement engines drive with motor power, the lubricant oil temperature remains at a lower level than in a conventional gasoline vehicle. This study analyzed the effect of cylinder liner temperature and lubricant oil temperature on engine friction. The results showed that, although the lubricant oil temperature was hardly significant, the liner temperature had an effect on piston friction. It was found that raising the temperature of the middle section of the cylinder liner was the most effective way of reducing piston friction.

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When the initial reaction temperature is low, the oxidation process of alkanes with three or more carbon atoms is characterized by the low temperature oxidation (LTO) process. This process is controlled by RO2 Chemistry and H₂O2 Chemistry (Route 1). When the initial temperature is higher than LTO end temperature, the oxidation proceeds without LTO process. In this condition, the reaction proceeds by the β-scission of alkyl radical, producing alkene and small alkyl radical (Route 2). At even higher temperature, the direct decomposition reactions of fuel molecule control the reaction process (Route 3). The rate determining processes of Route 1 are the decomposition of keto-hydroperoxide, generated by the reactions RH → R → ROO → QOOH → OOQOOH Ket(Ald)OOH , and the dissociation of H₂O2, H₂O2 → OH + OH. The rate determining process of Route 2 and 3 is the chain branching reaction H + O2 → OH + O.

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In this study, the authors focus on one of next-generation bio-alcohols, isopentanol, and have developed a detailed chemical kinetic model for isopentanol which has high- and low-temperature chemistry. This paper describes the model formulation and validation. Also, the model is applied to a homogeneous charge compression ignition (HCCI) engine to reproduce combustion phasing and behaviors of intermediate temperature heat release (ITHR). The simulations with the detailed model developed in this study have good agreement with experiments.

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Engine EGR reforming was examined with a goal of improving the fuel consumption of engines burning ethanol-blended gasoline. The catalyst carriers of Rh catalyst were examined and optimized by using a flow reactor. The improved “carrier of ceria” is the most suitable. And engine EGR reforming was examined by an experimental engine. With pure ethanol, engine EGR reforming was possible at lower temperature compared with gasoline, and the fuel consumption was improved. With E85, the hydrogen in reforming gas was increased with the optimized catalyst.

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For an improvement of fuel consumption and emission purification, engine operating parameters, such as a valve operation, become variable. Therefore, an engine operation at a transient state was increased and an accuracy was increasingly required to control an air fuel ratio at transient state. This paper investigated an adaptive gain control system which was respectively equipped to the feedforward and the feedback controller. Then, a robustness against operating condition and system parameter were also investigated by comparing with some single side adaptive controller. A high accuracy control result and robustness of the controller were shown by the experimental results.

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This study investigated the mechanism producing the multi-stage heat release behavior of a supercharged HCCI engine operated on blended fuels of DME and methane. These aspects were investigated by making spectroscopic measurements of in-cylinder gas, FTIR analysis of intermediate products and by conducting chemical kinetic analyses. The results revealed that the DME is mainly consumed during cool flame and accumulate HCHO. In addition, in the first-stage heat release of the main combustion, HCHO is consumed and CO is produced. Meanwhile, methane is not appreciably consumed in the first-stage heat release of the main combustion and consumed just prior to the second-stage heat release. That explains why the heat release of the hot flame occurred in two distinct stages.

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The ignition timing of homogeneous charge compression ignition (HCCI) combustion engines is the important factor which should be controlled. In this study, effects of adding reaction intermediates to n-heptane-air mixture on auto-ignition delay time are evaluated. Effects of additives on the ignition timing control are large at low temperature, and these tend to become small at high temperature. Especially, it is appropriate to supply additives at lower temperature than the temperature of negative temperature coefficient in order to control the ignition timing. C₂H₂ and C₂H hardly influence the ignition time in high temperature conditions though it has the effect of promoting the ignition in low temperature conditions.

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Homogeneous Charge Compression Ignition (HCCI) combustion has attracted considerable interest as a new combustion concept for internal combustion engines in recent years because of their potential for high efficiency and clean combustion. However the HCCI combustion process has two issues to be resolved: ignition timing control, slower combustion. Authors focused attention on exhaust gas recirculation (EGR) to resolve these issues. In this study, the influence of EGR on ignition in an HCCI engine was investigated by using an actual engine and analysis of chemical reactions based on chemical kinetic simulations.

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A catalytic muffler design is required the structure that makes emission gas flow smoothly in the muffler for improving the purification efficiency. This paper focuses on the design environment including uncertain design information and applies a preference set-based design method to the catalytic muffler design in the design phase. The design method can obtain a ranged set of design solutions that satisfies performance requirements by representing uncertain design information as ranged sets.

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In this study, we have constructed 1-dimensional model to simulate chemical reaction in diesel oxidation catalyst. And we have predicted oxidation reaction in the diesel oxidation catalyst using elements data of diesel engine exhaust gas. In addition, we have investigated optimization of the amount of platinum site in the diesel oxidation catalyst, which is placed before diesel particulate filter or urea SCR system, using the 1-dimensional model.

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Diesel Particulate Filter (DPF) is regenerated in particulate matter (PM) oxidation reaction when PM was loaded. In this report, it makes a study regarding basic calculation method of kinetics parameters using the oxidation reaction process of PM that was simulated by laboratory experiments with synthetic gases. Additionally, it reports on the results of examining the relation between temperature and time when a DPF is regenerating, using kinetic parameters.

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A new membrane filter made of SiC nano-particles with a 5nm thickness of oxide-layer, in which Pt particles with a few nano-meters size is imbedded, was proposed for reduction of temperature in oxidation reaction of diesel nano-scaled particulates in regeneration process of DPFs.

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It is recognized that N2O, having 310 times CO₂ global warming potential, tends to be produced due to NH3 slip from Urea SCR catalysts. To investigate N2O formation mechanism and reduce its emission, we have conducted both experiment and chemical kinetics simulation studies. The results have shown that the reactions associate with NH3 and NO produces N2O in the oxidation catalyst and its peak appears around a 200℃ exhaust gas temperature. It has also been found out that the catalytic volume and urea injection quantity should be optimized to prevent NH3 slip.

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The effect of diesel exhaust aftertreatment system on exhaust gas emissions during cold-starting was evaluated experimentally. The aftertreatment system which consisted of diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) was used. Exhaust gas emissions were measured at front and rear of the aftertreatment system, and intensity of exhaust odor was assessed by sensory assessment. The results indicate that HC was adsorbed on the aftertreatment system and desorption of some of HC occurred with elevation of exhaust temperature. HC which did not adsorb onto the aftertreatment system was discharged from a tail pipe as a white smoke. Some of HCHO, which is the primary odor component of diesel exhaust, was also adsorbed on the aftertreatment system. It was confirmed that odor intensity at the rear of the aftertreatment system was weaker than that of the front side.

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Future heavy duty diesel exhaust emissions are supposed to be regulated based on cold start and warm up emissions. Thus, diesel engine tests were carried out to investigate ignition, combustion and emission characteristics at low and normal coolant temperatures using fuels having different chemical properties and cetane numbers. The results show that low coolant temperatures and/or low cetane number fuels tend to delay combustion, resulting in influencing emissions characteristics particularly at low load.

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Recently, boost pressure and EGR ratio are set to increase for improving performance of diesel engine, and pressure in a cylinder is higher than that of conventional engine. Therefore, it is necessary to understand effect of high ambient pressure in a cylinder on diesel spray. In this study, diesel spray was formed in high pressure vessel that simulated high boost engine. Shadow images of spray were captured for understanding structure of spray, and time-resolved particle image velocimetry (PIV) was applied for observation of spray behavior. As the results, axial velocity of diesel spray was reduced with increasing of ambient pressure. Downstream spray was caught up and overtaken with upstream spray, was clarified.

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A supercharging system together with a mechanical supercharger and a turbo charger was investigated with experimental and numerical analysis in a diesel engine use for the commercial vehicle. The mechanical loss of a mechanical supercharger was reduced by putting a turbo charger together. Furthermore, it was found that the fuel consumption as a vehicle could be improved by optimizing power train specifications. And it was accomplished by increase of the low-end torque which was produced by a mechanical supercharger.

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Engine performance, combustion characteristics, and emissions were investigated using a DI diesel engine with FAME fuels such as methyl laurate and methyl oleate. Compared with gas oil operation, the smoke densities and HC emissions with FAME fuels showed significant decreases over the tested load range. To discuss the combustion characteristics of the FAME fuels, basic experiments with single droplets were conducted and the combustion behavior was analyzed by shadowgraph photography. The results show that soot formation of the FAME fuels (oxygenated fuels) is strongly suppressed due to the characteristics of this kind of fuel.

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According to results from detailed chemical kinetics modeling, methyl decanoate, MD, shows shorter ignition delays than those of n-heptane over the whole range of the initial temperature. In the second report, the high ignitability in a case without LTO had been elucidated by means of contribution matrices. In the present report, the high ignitability in a case with LTO was analyzed. At the beginning of an ignition process, OH is quickly generated by a path of MD + O2 = MD2j + HO2 to MD2OOH4O2 = MDket24 + OH due to a low C-H bond energy of the α-C atom to the carbonyl group. Therefore, an LTO preparation phase starts with a high OH concentration. In an LTO phase, a large amount of CH2CHO is generated by decomposition of fragmental ketooxy radaicals and aldehyde radicals. As a result, CH2CHO + O2 = CH₂O + CO + OH + 214 kJ increases the LTO end temperature, compared with that of n-heptane.

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It is a very important and urgent subject that internal combustion engines have better combustion potential for clean and high efficiency performance for energy-saving future. A new combustion concept, Diesel Staggered Premixed Ignition with Accelerated oxidation (D-SPIA), was developed for lower exhaust emissions and carbon dioxide (CO₂). This concept is based on divided fuel injections before TDC. Although the D-SPIA is a type of PCCI (Premixed Charge Compression Ignition), it has a distinct feature of double premixed combustion by optimum injection quantities and staggered timing, which can achieve an ideal heat release rate for low pollutant emissions and fuel consumption.

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Combustion robustness of the new concept combustion named D-SPIA was investigated for ambient temperature, engine coolant temperature and fuel cetane quality. Through these tests, we found out that heat release rate of the D-SPIA could be maintained at a desired crank angle by control of air-fuel ratio and/or injection timing based on changes in the environmental conditions and stability of the D-SPIA was maintained even when using of a low cetane index fuel. Finally, we tested a prototype engine using the D-SPIA and verified that it had a potential to meet Euro6 regulation without any DeNOx after-treatment and fuel penalty.

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To analyze the carbon monoxide (CO) emission sources in diesel combustion, an in-cylinder CO imaging technique using two-photon excitation LIF was developed. While overlapping of the light emitted by the soot particles, over the weak CO fluorescence, became a serious problem, it was solved by optimizing the imaging direction, and by increasing the level of laser irradiation used for LIF excitation. The results of in-cylinder CO-LIF imaging were compared with the results obtained with CFD simulation and the agreement was found to be excellent. The results of LIF and CFD showed that the major source of CO emissions under low load conditions is the over-diffusion of the pilot sprays. These prevent the local temperature from rising, sufficiently to oxidize the CO.

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Biodiesel fuel (BDF) is a promising carbon neutral fuel. However, BDF has high viscosity and poor volatility. In this study, it aims at the reformulation of physical properties of BDF by mixing a low boiling point fuel. In this paper, the influence that the difference of alcohol fuels exert on combustion characteristic of BDF is understood by using methanol, ethanol, 1-propanol and 1-butanol as a low boiling point fuel. In combustion experiment, the ignition characteristics and soot formation characteristics are evaluated to conduct chemiluminescence photography and direct photography in the constant volume combustion vessel.

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For diesel combustion, the ignitability of butanol and ethanol are too low and the viscosity of unesterified vegetable oil is too high, but blends of these two kinds of fuels have sufficient ignitability with low viscosity, as well as low soot formation characteristics due to the oxygen content. The solubility of butanol and vegetable oil is very high and a wide range of blends is possible, while the blending of butanol, ethanol, and vegetable oil is limited to certain ratio. The experimental results showed that smokeless, low NOx, and low engine noise with a blend of the same volumes of butanol and unesterified vegetable oil and a blend of 40%, 20% by volume of butanol-ethanol with vegetable oil were established with optimum pilot injection and high EGR in a DI diesel engine.

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This study aims to obtain a strategy for optimizing the combination of injection conditions and combustion chamber geometry to achieve low unburned species emissions with high thermal efficiency and low NOx emission in a natural-gas dual fuel engine. Experiments were performed using a single-cylinder test engine with a common-rail injection system varying piston bowl diameter. The results showed that larger bowl diameter provides lower THC and CO emissions at earlier pilot injection timings in single-stage injection mode. In the case of two-stage pilot injection, larger bowl diameter improves THC and NOx emissions for smaller amount of first injection, on the other hand, piston bowl diameter has weak influence on exhaust emissions for larger amount of first injection.

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Recent years, engine calibration process has been required to be more sophisticated. It is possible to improve efficiency of calibration by making good use of models, and calibration process where models are introduced is called Model Based Calibration (MBC).MBC has been showing its validity to some extent. But it is necessary to spend much time still and all at boundary detection that is indispensable for accurate engine modeling. Especially for diesel engine calibration, it takes much time, because there are large numbers of calibration parameters. In this paper, the newmethodology for boundary finding measurement is introduced.

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A model is developed for analyzing the fundamental static and dynamic performance of a power steering. The basic inertia, stiffness and damping properties of each component are taken into consideration. A dynamic friction model is introduced for precise modeling of the losses of the gear meshes, the yoke support and the bearings. The torque ripple generated by the universal joints of the intermediate shaft is considered. The assist motor (brushed DC type) and its power electronics are represented in a 4-quadrant model. Static and dynamic responses of this power steering model are validated against experimental data.

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Pedestrian detection is one of the key technologies for driver assistance systems. This paper proposes a sensor fusion system for pedestrian detection using an electrically-scanned millimeter wave radar and a stereovision. To improve the sensitivity of the radar for pedestrians, the system controls the directivity of the radar beam on the basis of the detection results from the stereovision. And the reliability for the detected radar signals is estimated by using the Dempster-Shafer evidence theory in order to determine precisely whether pedestrians are present or not. Some experiments in a road environment confirm the effectiveness of the proposed system.

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We developed a new propane burner satisfying the requirements of the localized fire test for hydrogen fuel tank proposed by SAE. This paper introduces the specifications of this burner, and reports its characteristics as determined from various fire exposure tests in order to provide data that would be useful for the design of automotive compressed fuel cylinders. Our fire exposure tests included localized and engulfing fire tests to compare TPRD activation time, cylinder burst pressure and other parameters among different flame configurations and to identify the effects of an automotive compressed fuel cylinder on localized fire test results.

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Fatigue strength of lapped weld joint in use of fatigue improvement welding process (MX-MIG process) which can improve the weld toe shape and decrease the residual tensile stress was investigated. As a result, fatigue limit at the weld toe of MX-MIG process could improve to 1.6-1.8 times compared with conventional welding process. Moreover, fatigue strength at the start point of lapped weld joint which has the possibility of crack initiation site in actual automobile components was improved with the combination of MX-MIG process and the extension bead. The light-weighting of chassis parts will be possible by application of MX-MIG process.

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Damaging phenomena of cutting tools were investigated to improve machinability of high-hardness die steels. The results showed that several types of adhesive materials were formed on the edges of cutting tools, depending on chemical compositions of die steels. Based on the results of this study, it was concluded that formation of particular adhesive materials leaded to improvement of cutting tool life.

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Deterioration mechanism of epoxy structural adhesives by water absorption was examined. Bonding strength decreased with water absorption time, and hydrolysis of adhesive occurred. Bonding strength correlated with degree of hydrolysis defined using peak intensity ratio in Fourier Transform Infrared Spectroscope (FT-IR). Hydrolysis was confirmed in weld-bonding parts of repossessed car, therefore, deterioration of bonding strength in market was able to evaluate using degree of hydrolysis. It was assumed that the water preferentially diffuses at interface between adherent and adhesive in early stage, and then diffuses from whole edge into adhesive layer. Hydrolysis would proceed according to this water diffusion process, and bonding strength and failure mode would be determined by magnitude relation between bulk strength and bonding strength at interface.

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A longitudinal control method is proposed for energy saving using local traffic information. The control method determines the traction and brake forces to reduce acceleration and deceleration of the vehicle, treating local traffic information such as front vehicles and signals as obstruction for eco-driving. The control method consists of two algorithms: one generates rough velocity patterns for eco-driving, and the other controls the vehicle using based on optimal control theory referring to the velocity pattern. This paper presents details of the proposed control method and simulation results obtained under different conditions, and clarifies the relationship between energy-saving effect and traffic information available in the controller.

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This paper investigates legibility of display symbols on one and multiple display locations of TFT-LCD instrument panel. In the experiment with the driving simulator, the subjects were instructed to judge the shape of the symbol when TFT-LCD instrument panel displayed one of five symbols while driving. The percentage of correct answer and the reaction time were analyzed.

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