We focused on low-cost hollow extruded aluminum materials and worked on developing the manufacturing method of the aluminum rear lower arm by cold press. We developed the rear lower arm made of extruded aluminum, which showed a great reduction in cost and a lightning effect comparing to those of die-casting, by establishing elementary technics in structure details, alloying element, junction process, etc..

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In order to correctly identify the collision point when reconstructing a traffic accident, it is important to understand the mechanism of scattering phenomenon of broken parts in traffic accidents. However, few studies have been conducted to clarify the mechanism of such phenomenon based on actual collision tests. This paper classifies the phenomenon according to the mechanism and clarifies each characteristic. The analysis is based on more than 100 actual collision tests.

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The multiple-link mechanism adopted for the variable valve event and lift(VVEL) system is connected mechanically from the drive shaft to the output cam, providing high-speed and friction characteristics superior to those of other similar types of variable valve lift systems commercialized to date. It was necessary to develop new technologies for ensuring the reliability of the many different types of sliding parts used in the VVEL system.
This paper describes the outline and application examples of newly developed lubrication analysis methodology which is applied to optimization of the shapes of sliding surfaces and link parts in order to realize reliability and low friction simultaneously. In this analysis methodology, various types of simulation techniques such as mechanism analysis, dynamic stress analysis, EHL analysis and simulations for predicting oil flow rates were combined to quantify the complex types of force inputs, contract pressure distributions and sliding velocity changes.

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A combustion concept was proposed to reduce unburnt THC from gasoline direct injection engines during cold-start. (1) The retarded ignition control with the split injection, the 1st injection timing is the later period of compression stroke and the 2nd one is the early period of expansion stroke was able to heat the exhaust gas up more than 700 deg.C at 20 seconds after the engine start. (2) Combustion stability at retarded ignition was improved exceedingly by using the fuel-spray directed under the spark plug and the step-shaped piston. The fuel injected at the 1st injection timing was guided around the spark plug so stable stratified mixture was generated until the retarded spark timing. (3) There was no penalty at full load conditions with the proposed combustion concept, because required step height on the piston for the concept was considerably low so mixture distribution at full load condition was not affected by the piston geometry.

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The purpose of this work is to investigate the DME fuel adaptability of a high pressure pump with a suction control type fuel metering system which is used in a mass-produced common rail type diesel injection system, and to modify the fuel system components for DME. It was verified that the suction control type fuel metering system had adaption to DME fuel. The high pressure fuel system components such as rail volume, rail outlet orifice and high pressure pipe were optimized for DME, and very stable injection performances were obtained by the modified DME injection system.

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In the development of the Hybrid electric vehicle motor drive system, we found the coil winding change effective as a method of improving the electric maximum rotation speed limit. For seamless switching at continuous torque, we adapted the automotive parts by choosing semiconductor devices. We achieved the product by utilizing this technology and the control improvement.

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The adaptive assist control generated motor assist map which can the most efficiently use the HV system from running environment and operation of the driver, battery state of charge that time automatically was developed. It is shown that it reduced variance of the improvement of fuel economy effect of HV in which the operation of the driver varies in this control, and again, that it can reduce the fuel consumption in comparison with the conventional control for various running patterns such as urban district and traffic congestion more by simulation and experimental vehicle.

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A new parking-aid system using an All-Around View system (AVS) that supports multiple turns is proposed. This system calculates the parking path depending on the steering angle at the initial position of the parking maneuver. This paper presents a method of parking path calculation and investigates the number of required turns and space to complete the parking maneuver. This method is able to find a path even for small parking spaces. Finally, the human-machine-interface with which the driver can set the target position and select the parking path on the AVS screen is described.

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FFor providing energy saving route guidance by the navigation system, it is efficiency not only to find the shortest route and congested routes but also to use the altitude information of the candidate routes. This paper considers the relation of the altitude information and the energy saving route by setting the actual sloping routes and taking the fuel consumption data on these routes. We investigate how to implement on map data in the Kiwi format and a dynamic re-route calculation based on Bayesian statistics.

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Nanoparticle emission characteristics of a MPI gasoline-engine vehicle (particle mass/number and size distribution measurement) were investigated by using gasoline with metal-containing additives like methyl-cyclopentadienyl manganese tricarbonyl and ferrocene. Mn containing nanoparticle emission was observed when Mn containing additive was used, and the number and total amount of them increased as the dosage increased. The same phenomenon of Fe containing nanoparticles was observed up on the usage of Fe containing additive. The large portion was nanoparticle of diameters between 5nm and 50nm, and increase of particle number, especially diameters under 20nm was observed even at lower dosage level of metal-containing additives.

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New expressions are introduced to indicate the contribution rate between members for load transfer in vehicle bodies. Load transfers from the loading and the supporting points are expressed using U∗ individually, and the summation of both U∗s is defined as U∗sum. We propose the histogram representation of U∗sum as a frequency diagram with regard to the number of FEM elements. The histograms are depicted for modeled bodies under torsion, which show that the main role of the windshield is the load transfer to the roof panel. The histogram indicates the insufficiency of oversimplified modeling of structures.

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Transfer Path Analysis is a key technology for tackling with the noise and vibration problems, and the precision of the input identification influences the result of contribution analysis. This paper presents a new input identification method based on the apparent-mass estimation. Then variance of the identified force is estimated and reliability coefficient is introduced to evaluate the input identification accuracy. To avoid the inversion process of ill-conditioned frequency response functions matrix, the apparent-mass matrix is directly estimated in a vibration test. In this paper, simulation and vibration test are used to compare the accuracy of two identification methods.

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Although warning systems are widely introduced to improve traffic safety, they should not confuse driver's judgment due to inappropriate presentation. This paper analyzes false alarm problem of the warning system based on the data obtained in driving simulator experiment. We supposed nuisance warning that comes from the inconsistency between driver's subjective judgment and warning threshold of the system. Allowable false alarm level of the system is considered.

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Effect of curve character on drivers' choice of curve entering speed was investigated using a driving behavior database distributed by the research institute of human engineering for quality life (HQL). Based on data obtained at 77 curves with 97 to 528 experimental trips by 4 to 28 subjects, a prediction model of median of curve entering speed was developed in which radius of curvature and velocity tendency before and after the curve are effective factors for prediction.

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The effect of improved visibility at night by the adoption of the Adaptive Front-lighting System is promising. However, the effectiveness evaluation considering the human characteristics of the lighting control system is not enough. In order to confirm 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. This study investigated the influence of the lighting control of the driver by using the driving simulator. And we simulated the driving behavior of the lighting controlled by using the variable preview time model. As a result, the effect of the lighting control was clarified.

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The goals of this research are to understand relationship between head tilt strategy and motion sickness incidence and apply its result to the design of comfortable vehicle control. So far, we proposed a mathematical model of the motion sickness incidence caused by the head movement in 3D space based on subjective vertical conflict. This paper analyzes effect of the head movement on decrease of motion sickness incidence using the mathematical model. The estimated motion sickness incidence using the proposed model showed that the head tilts toward the inertial acceleration including drivers head movement have effect to reduce motion sickness incidence.

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A human body FE model representing a pregnant occupant has been developed based on the existing THUMS model. Using the model, the study conducted frontal impact simulations to compare the occupant motions with and without wearing the seatbelt. The results indicated that the loading to the occupant body could be mitigated by wearing the seatbelt. The model also showed smaller abdominal deformation when the seatbelt was located at the inferior abdomen.

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To investigate effect of muscle activity in pre-impact on injury outcome, we developed a human whole body FE model with muscular solid elements which can simulate 3-D geometry of each muscle and muscle stiffness change for the inputted activity, and performed side impact simulations using the whole body FE model. The simulation results showed that muscle activity in occupant bracing could reduce forces from a door in lower speed impacts and cause stress concentration at the bones of the arm and the shoulder not only in near side but also in far side.

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In the present study, the factors that can affect a pedestrian's chest injuries by the front configuration of a vehicle were investigated using a finite element analysis. In a bonnet-type car-pedestrian accident, the pedestrian's chest impacted the bonnet top at a low velocity according to the rotation of the pedestrian's entire body around the car. The stiffness of the bonnet top where the chest impacted was distributed, and thorax deformation was small and uniform. In a one-box type vehicle-pedestrian accident, the pedestrian's chest was directly impacted by the front of the vehicle at a high velocity. Because the chest was hit by the stiff windshield frame, the thorax was deformed locally. The results showed that vehicle configuration can affect the impact velocity to the chest, and the stiffness of the vehicle structure can affect chest deformation and its mode.

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A robust crosswalk recognition method is proposed from an image sequence captured by an on-board single camera. This method is applied to a driver assistance system for preventing pedestrian accidents utilizing the information of the crosswalk location. A crosswalk in the image is recognized by calculating the “cross ratio” of the edge points, which is an invariant of perspective projection. The proposed method achieves robust recognition using prior knowledge about the crosswalks in the image and consistency check through the image sequence. The validity of the proposed method was confirmed by a number of public road image sequences.

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Model-based technique for the variable valve engine calibration process, employing engine cycle simulation and polynomial regression analysis, has been developed. In the present technique, the simulation model tuning and validation were done, followed by the creation of a dataset for the regression analysis of charging efficiency using 4th-order polynomial equation. D-optimal design, robust least square method and likelihood-ratio test were demonstrated to yield the robust and accurate regression model. The reliability of the implementation control model, which considers the effect of gas dynamics in the intake manifold, was confirmed using a model-in-the-loop simulation.

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Experimental analysis of the oil consumption factors in turbocharged gasoline engine has been conducted. The oil consumption factors were separated to turbocharger, blow-by gas, oil evaporation, valve guides and piston rings. Consumption from turbocharger and valve guides was investigated by separating the oil line. Oil evaporation was investigated by using the oil with different volatility characteristics. The major contributions are oil loss via the piston ring (55 to 75 percent), oil evaporation (15 to 40 percent) and blow-by oil consumption (2 to 15 percent) at full load. Consumption from turbocharger and valve guides is almost zero percent.

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In this paper, a new oil evaporation model was developed, combining a thermo-hydrodynamic lubrication model with a conventional oil evaporation model considered the energy balance on the oil film surface. In addition, the effects of types of lubricant, the oil film thickness and the liner temperature in the evaporated oil from the liner were examined. Moreover, the calculated evaporative oil was compared with the measured oil consumption of a gasoline engine. The relationship between the evaporated oil, the lubricant viscosity, and the oil film thickness were clarified by using this model. The results showed that the calculated oil evaporation from the cylinder wall closely corresponded to the measured oil consumption under low load conditions. Under a high load and a high-speed conditions, the measured values exceeded the calculated values.

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The activated carbon canister is mainly used as a storage device of hydrocarbon vapor from the fuel tank. The aim of this study is, to develop a canister with improved performance by decreasing the amount of hydrocarbon diffusion. Experimental results of the hydrocarbon diffusion in the canister and the behavior of butane, a major component of hydrocarbon, are reported in this research. A calculation method of hydrocarbon diffusion is derived that can predict canister performance.

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A newly developed small-sized IES (inductive energy storage) circuit with a semiconductor switch at turn-off action was successfully applied to an ignition system. This IES circuit can generate repetitive nanosecond pulse discharges. An ignition system using repetitive nanosecond pulse discharges was investigated as an alternative to conventional spark ignition systems in the previous paper(1)(2). The ignition system using repetitive nanosecond pulse discharges was found to improve the inflammability of lean combustible mixtures, such as extended flammability limits, shorted ignition delay time, with increasing the number of pulses. In this paper, we examined the ignition characteristics under diluted condition considering EGR. In addition, the authors sought for the mechanisms for improving the inflammability in more detail using conventional ignition plug. Moreover, an application of this ignition system to a SI engine was conducted and the diluted limit was investigated. The result shows that the diluted limit is extended from 17.5 % to 22.5 % in EGR ratio and that thermal efficiency is improved by 5% by replacing the ignition system from a conventional one.

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In order to reduce NOx emissions in a DI diesel engine, we pursued the measurement and calculation method of EGR (Exhaust Gas Recirculation) rate under the internal EGR. As a result, the following conclusions were obtained. (1)The internal EGR rate was estimated by the measurement and calculation of oxygen concentration in the intake port. (2)The EGR rate partially did not correspond in comparison with NOx reduction rate because of the heterogeneous mixture of air and EGR gas in the intake port. (3)This was proved by the calculation under CFD and measurement of gas temperature in the intake port.

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The elementary reaction scheme including a soot model for a diesel surrogate fuel by Golovitchev and the soot oxidation model for surface reaction by Nagle, et al. have been incorporated into the GTT-CHEM code constructed by the authors' group, in order to numerically predict soot emission from a direct injection diesel engine. The reaction rate constants have been optimized to reasonably reproduce the φ-T map for soot generation and the ignition delay data. As a result, the experimental results of soot and NO emissions as well as the rates of heat release under various injection conditions have been reproduced reasonably well by means of three-dimensional chemical kinetics calculation using the GTT-CHEM code.

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In order to reduce NOx emissions and fuel consumption in a direct injection (DI) diesel engine, we pursued the flow of EGR (Exhaust Gas Recirculation) gas in the cylinder, combustion and exhaust emissions characteristics under the internal EGR by the theoretical and experimental method. As a result, the following conclusions were obtained. The flow of EGR gas in the cylinder during the intake and compression stroke was clarified. And we could find the relations between the flow of EGR gas and the engine performance, exhaust emissions and combustion characteristics.

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High boost and high EGR diesel combustion is recently obtained much attention to reduce exhaust NOx emission. EGR cooler is one of the key elements of EGR system and soot deposits inside the EGR cooler should be eliminated to maintain the high performance of EGR cooler. Then, characterization of soot deposited in the EGR cooler was reported as the fundamental study of deposits elimination. Deterioration of heat transfer performance and mass of deposits were investigated using oxidation method previously developed by the authors. Microscopic investigation of deposits layer resulted deposits distribution inside the EGR cooler. Local deposits layer thickness on the heat transfer surface was greatly influenced by the surface configuration. Bulk density of deposits layer was around 0.2 g/cm³ and was extremely smaller than PM density reported in the literatures.

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In this study, to use bio-butanol, which is soluble in gas oil, the fuel properties, combustion characteristics and exhaust emissions of the blend fuels of 1-butanol and JIS No.2 gas oil are investigated using a DI diesel engine. The 1-butanol content of test fuels is 10-50 mass%. With increasing 1-butanol content, the ignition delay of the blend fuel becomes longer and the HC and CO emissions increase at low load condition. However, the smoke emissions decrease with increasing 1-butanol content. Especially, with 40mass% 1-butanol content the smoke emission reduce about 80% at full load condition.

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Hydrogen engines are required to provide high thermal efficiency and low nitrogen oxide (NOx) emissions. There are many possible combinations of injection timing, lambda and EGR rate that can be used in a direct-injection system for achieving such performance. In this study, NOx emissions of natural aspirated 4 cylinders engine with management strategies involving the injection timing, ignition timing, lambda and the EGR rate were evaluated under a Japanese JE05 emissions test cycle. Finally, the paper projects the potential of direct injection hydrogen engine for obtaining high output power and attaining low NOx emissions of 0.7g/kWh under the emission test cycle with NSR catalyst.

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Numerical analysis has been performed for turbulent flow in a 90-degree bend pipe with half-tip ribs by using an algebraic Reynolds stress model and boundary fitted coordinate system. Calculated results are compared with the experiment in order to confirm the validity of the presented model and clarify the mechanism of drag reduction. It has been found that the calculation can reproduce reasonably the measured velocity profiles including secondary flow vectors. Besides, calculated results suggest that drag reduction must be caused by the secondary flow of the second kind which is produced by anisotropic turbulence through half-trip rib.

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In order to improve the energy efficiency, HEV with CVT between the motor and the engine in addition to between the engine and wheels is considered. For the case that the engine and the motor have variable angular velocity ratio, the energy optimal control is derived from the system that has the virtual subsystem that gives the reference angular velocity, the actual subsystem that follows the reference velocity, and the virtual nonlinear damping that combines the subsystems. In the 10-mode driving simulation, the new control shows excellent speed following performance. The energy consumption is 11.3% less than the energy optimal control of the first report.

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This study was conducted for the purpose of quantitative evaluation about contributing factors (driving speed pattern, cold-start and accessories usage) to passenger car's CO₂ emissions. CO₂ emissions were quantitatively estimated by a CO₂ emission model based on 16 passenger car's driving data collected in real world for a long term. The results show that CO₂ emission factors contributed by driving speed patterns in real world mostly exceed the factors measured 10·15 mode test. And the contribution to CO₂ emission by cold-start and usage of accessories were 13 - 31 % to annual CO₂ emissions.

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This report describes examination of information to inside and outside vehicles and human machine interface of platoon systems. This platooning system consists of trucks of a autonomous driving, and aims at CO2 reduction and energy saving. Proposed HMI is taking into consideration the safety of a platooning system, and the sense of security of a driver. Furthermore, these HMI are constructed on real vehicles and the basic experiment shows availability.

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The aim of this work is to establish the equation for predicting cetane number of biodiesel fuels based on their composition or properties. For conducting the regression analysis, 34 fuel-samples with wide variety of ignition quality were made by mixing 5 kinds of biodiesels and 5 kinds of FAME reagents. The relationship between cetane number, which was measured with the constant-volume combustion test, and the fuel properties such as iodine value, saponification number and boiling point were analyzed. Based on these results, 4 kinds of regression equations were proposed and their accuracies were examined. Obtained results show that the regression equation based on fuel composition can give cetane number with high accuracy, while it can be roughly predicted only from iodine value.

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We have developed the simplified chemical kinetic model of n-heptane, n-pentane and propane based on the knowledge of RO₂ and H₂O₂ chemistry, which roles in the hydrocarbon ignition mechanism were clearly understood in our previous studies. The model consists of common and fuel specific reaction parts. Common part includes C₀-C₂ small species related reactions taken from detailed model without modifications. Fuel specific part includes lumping reactions of RO₂ chemistry. However the methodologies of lumping are almost same for each fuel, except hydroperoxy alkyl radicals and ketohydroperoxide reactions which rate constants are determined from the comparison of low temperature oxidation characteristics calculated by detailed chemical kinetic model. It was confirmed that this simplified model, only 26 species and 51 reactions in case of n-heptane oxidations, well reproduces the results of detailed model without missing the kinetics of hydrocarbon ignitions.

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A honeycomb shaped paper was prepared by paper making technique and the following molding and calcination process. On the porous paper-honeycomb, precious metal catalyst containing Pd dispersed on Mn-substituted lanthanum hexa-aluminate(MPB) as one of the catalyst contents was coated and the exhaust gas purification performance was studied by measurement of the gas emitted from two wheeled vehicle(125cc). NOx, CO and HC gas contained in the exhaust gas, were detected lower than the value of EURO3 emission regulation.

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Two conditions of the picture presentation method in the driving simulator (DS) were compared for the estimation of driver gap acceptance in turning across opposite traffic. One was the stereo condition in which the picture was presented with binocular disparity consistent with the simulated scene. The other was the 2-D condition in which the picture was presented with zero binocular disparity all over the picture. We did not find significant differences between the estimations in the two conditions for the acceptance threshold and for the risk score at the acceptance threshold. Requirements for the picture presented in DS was discussed.

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